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4coder/non-source/test_data/lots_of_files/ppltasks.h

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Testing data
2018-03-16 18:19:11 +00:00
/***
* ==++==
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
* ==--==
* =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*
* ppltasks.h
*
* Parallel Patterns Library - PPL Tasks
*
* =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
****/
#pragma once
#ifndef _PPLTASKS_H
#define _PPLTASKS_H
#include <pplconcrt.h>
// Cannot build using a compiler that is older than dev10 SP1
#ifdef _MSC_VER
#if _MSC_FULL_VER < 160040219 /*IFSTRIP=IGN*/
#error ERROR: Visual Studio 2010 SP1 or later is required to build ppltasks
#endif /*IFSTRIP=IGN*/
#endif
#include <functional>
#include <vector>
#include <utility>
#include <exception>
#include <algorithm>
#if defined (__cplusplus_winrt)
#include <windows.h>
#include <ctxtcall.h>
#include <agile.h>
#include <winapifamily.h>
#ifndef _UITHREADCTXT_SUPPORT
#ifdef WINAPI_FAMILY /*IFSTRIP=IGN*/
// It is safe to include winapifamily as WINAPI_FAMILY was defined by the user
#include <winapifamily.h>
#if WINAPI_FAMILY == WINAPI_FAMILY_APP
// UI thread context support is not required for desktop and Windows Store apps
#define _UITHREADCTXT_SUPPORT 0
#elif WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP
// UI thread context support is not required for desktop and Windows Store apps
#define _UITHREADCTXT_SUPPORT 0
#else /* WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP */
#define _UITHREADCTXT_SUPPORT 1
#endif /* WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP */
#else /* WINAPI_FAMILY */
// Not supported without a WINAPI_FAMILY setting.
#define _UITHREADCTXT_SUPPORT 0
#endif /* WINAPI_FAMILY */
#endif /* _UITHREADCTXT_SUPPORT */
#if _UITHREADCTXT_SUPPORT
#include <uithreadctxt.h>
#endif /* _UITHREADCTXT_SUPPORT */
#pragma detect_mismatch("_PPLTASKS_WITH_WINRT", "1")
#else /* (__cplusplus_winrt) */
#pragma detect_mismatch("_PPLTASKS_WITH_WINRT", "0")
#endif /* #if defined(__cplusplus_winrt) */
#ifdef _DEBUG
#define _DBG_ONLY(X) X
#else
#define _DBG_ONLY(X)
#endif // #ifdef _DEBUG
// std::copy_exception changed to std::make_exception_ptr from VS 2010 to VS 11.
#ifdef _MSC_VER
#if _MSC_VER < 1700 /*IFSTRIP=IGN*/
namespace std
{
template<class _E> exception_ptr make_exception_ptr(_E _Except)
{
return copy_exception(_Except);
}
}
#endif
#ifndef _PPLTASK_ASYNC_LOGGING
#if _MSC_VER >= 1800 && defined(__cplusplus_winrt)
#define _PPLTASK_ASYNC_LOGGING 1 // Only enable async logging under dev12 winrt
#else
#define _PPLTASK_ASYNC_LOGGING 0
#endif
#endif
#endif
#pragma pack(push,_CRT_PACKING)
#pragma warning(push)
#pragma warning(disable: 28197)
#pragma warning(disable: 4100) // Unreferenced formal parameter - needed for document generation
#pragma warning(disable: 4127) // constant express in if condition - we use it for meta programming
// All CRT public header files are required to be protected from the macro new
#pragma push_macro("new")
#undef new
// stuff ported from Dev11 CRT
// NOTE: this doesn't actually match std::declval. it behaves differently for void!
// so don't blindly change it to std::declval.
namespace stdx
{
template<class _T>
_T&& declval();
}
/// <summary>
/// The <c>Concurrency</c> namespace provides classes and functions that give you access to the Concurrency Runtime,
/// a concurrent programming framework for C++. For more information, see <see cref="Concurrency Runtime"/>.
/// </summary>
/**/
namespace Concurrency
{
/// <summary>
/// A type that represents the terminal state of a task. Valid values are <c>completed</c> and <c>canceled</c>.
/// </summary>
/// <seealso cref="task Class"/>
/**/
typedef task_group_status task_status;
template <typename _Type> class task;
template <> class task<void>;
// In debug builds, default to 10 frames, unless this is overridden prior to #includ'ing ppltasks.h. In retail builds, default to only one frame.
#ifndef PPL_TASK_SAVE_FRAME_COUNT
#ifdef _DEBUG
#define PPL_TASK_SAVE_FRAME_COUNT 10
#else
#define PPL_TASK_SAVE_FRAME_COUNT 1
#endif
#endif
/// <summary>
/// Helper macro to determine how many stack frames need to be saved. When any number less or equal to 1 is specified,
/// only one frame is captured and no stackwalk will be involved. Otherwise, the number of callstack frames will be captured.
/// </summary>
/// <ramarks>
/// This needs to be defined as a macro rather than a function so that if we're only gathering one frame, _ReturnAddress()
/// will evaluate to client code, rather than a helper function inside of _TaskCreationCallstack, itself.
/// </remarks>
#if PPL_TASK_SAVE_FRAME_COUNT > 1
#if defined(__cplusplus_winrt) && !defined(_DEBUG)
#pragma message ("WARNING: Redefinning PPL_TASK_SAVE_FRAME_COUNT under Release build for non-desktop applications is not supported; only one frame will be captured!")
#define _CAPTURE_CALLSTACK() ::Concurrency::details::_TaskCreationCallstack::_CaptureSingleFrameCallstack(_ReturnAddress())
#else
#define _CAPTURE_CALLSTACK() ::Concurrency::details::_TaskCreationCallstack::_CaptureMultiFramesCallstack(PPL_TASK_SAVE_FRAME_COUNT)
#endif
#else
#define _CAPTURE_CALLSTACK() ::Concurrency::details::_TaskCreationCallstack::_CaptureSingleFrameCallstack(_ReturnAddress())
#endif
/// <summary>
/// Returns an indication of whether the task that is currently executing has received a request to cancel its
/// execution. Cancellation is requested on a task if the task was created with a cancellation token, and
/// the token source associated with that token is canceled.
/// </summary>
/// <returns>
/// <c>true</c> if the currently executing task has received a request for cancellation, <c>false</c> otherwise.
/// </returns>
/// <remarks>
/// If you call this method in the body of a task and it returns <c>true</c>, you must respond with a call to
/// <see cref="cancel_current_task Function">cancel_current_task</see> to acknowledge the cancellation request,
/// after performing any cleanup you need. This will abort the execution of the task and cause it to enter into
/// the <c>canceled</c> state. If you do not respond and continue execution, or return instead of calling
/// <c>cancel_current_task</c>, the task will enter the <c>completed</c> state when it is done.
/// state.
/// <para>A task is not cancellable if it was created without a cancellation token.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/// <seealso cref="cancellation_token_source Class"/>
/// <seealso cref="cancellation_token Class"/>
/// <seealso cref="cancel_current_task Function"/>
/**/
inline bool __cdecl is_task_cancellation_requested()
{
return ::Concurrency::details::_TaskCollection_t::_Is_cancellation_requested();
}
/// <summary>
/// Cancels the currently executing task. This function can be called from within the body of a task to abort the
/// task's execution and cause it to enter the <c>canceled</c> state. While it may be used in response to
/// the <see cref="is_task_cancellation_requested Function">is_task_cancellation_requested</see> function, you may
/// also use it by itself, to initiate cancellation of the task that is currently executing.
/// <para>It is not a supported scenario to call this function if you are not within the body of a <c>task</c>.
/// Doing so will result in undefined behavior such as a crash or a hang in your application.</para>
/// </summary>
/// <seealso cref="task Class"/>
/**/
inline __declspec(noreturn) void __cdecl cancel_current_task()
{
throw task_canceled();
}
namespace details
{
/// <summary>
/// Callstack container, which is used to capture and preserve callstacks in ppltasks.
/// Members of this class is examined by vc debugger, thus there will be no public access methods.
/// Please note that names of this class should be kept stable for debugger examining.
/// </summary>
class _TaskCreationCallstack
{
private:
// If _M_SingleFrame != nullptr, there will be only one frame of callstacks, which is stored in _M_SingleFrame;
// otherwise, _M_Frame will store all the callstack frames.
void* _M_SingleFrame;
std::vector<void *> _M_frames;
public:
_TaskCreationCallstack()
{
_M_SingleFrame = nullptr;
}
// Store one frame of callstack. This function works for both Debug / Release CRT.
static _TaskCreationCallstack _CaptureSingleFrameCallstack(void *_SingleFrame)
{
_TaskCreationCallstack _csc;
_csc._M_SingleFrame = _SingleFrame;
return _csc;
}
// Capture _CaptureFrames number of callstack frames. This function only work properly for Desktop or Debug CRT.
__declspec(noinline)
static _TaskCreationCallstack _CaptureMultiFramesCallstack(size_t _CaptureFrames)
{
_TaskCreationCallstack _csc;
_csc._M_frames.resize(_CaptureFrames);
// skip 2 frames to make sure callstack starts from user code
_csc._M_frames.resize(::Concurrency::details::platform::CaptureCallstack(&_csc._M_frames[0], 2, _CaptureFrames));
return _csc;
}
};
typedef unsigned char _Unit_type;
struct _TypeSelectorNoAsync {};
struct _TypeSelectorAsyncOperationOrTask {};
struct _TypeSelectorAsyncOperation : public _TypeSelectorAsyncOperationOrTask { };
struct _TypeSelectorAsyncTask : public _TypeSelectorAsyncOperationOrTask { };
struct _TypeSelectorAsyncAction {};
struct _TypeSelectorAsyncActionWithProgress {};
struct _TypeSelectorAsyncOperationWithProgress {};
template<typename _Ty>
struct _NormalizeVoidToUnitType
{
typedef _Ty _Type;
};
template<>
struct _NormalizeVoidToUnitType<void>
{
typedef _Unit_type _Type;
};
template<typename _T>
struct _IsUnwrappedAsyncSelector
{
static const bool _Value = true;
};
template<>
struct _IsUnwrappedAsyncSelector<_TypeSelectorNoAsync>
{
static const bool _Value = false;
};
template <typename _Ty>
struct _UnwrapTaskType
{
typedef _Ty _Type;
};
template <typename _Ty>
struct _UnwrapTaskType<task<_Ty>>
{
typedef _Ty _Type;
};
template <typename _T>
_TypeSelectorAsyncTask _AsyncOperationKindSelector(task<_T>);
_TypeSelectorNoAsync _AsyncOperationKindSelector(...);
#if defined(__cplusplus_winrt)
template <typename _Type>
struct _Unhat
{
typedef _Type _Value;
};
template <typename _Type>
struct _Unhat<_Type^>
{
typedef _Type _Value;
};
value struct _NonUserType { public: int _Dummy; };
template <typename _Type, bool _IsValueTypeOrRefType = __is_valid_winrt_type(_Type)>
struct _ValueTypeOrRefType
{
typedef _NonUserType _Value;
};
template <typename _Type>
struct _ValueTypeOrRefType<_Type, true>
{
typedef _Type _Value;
};
template <typename _T1, typename _T2>
_T2 _ProgressTypeSelector(Windows::Foundation::IAsyncOperationWithProgress<_T1,_T2>^);
template <typename _T1>
_T1 _ProgressTypeSelector(Windows::Foundation::IAsyncActionWithProgress<_T1>^);
template <typename _Type>
struct _GetProgressType
{
typedef decltype(_ProgressTypeSelector(stdx::declval<_Type>())) _Value;
};
template <typename _Type>
struct _IsIAsyncInfo
{
static const bool _Value = __is_base_of(Windows::Foundation::IAsyncInfo, typename _Unhat<_Type>::_Value);
};
template <typename _T>
_TypeSelectorAsyncOperation _AsyncOperationKindSelector(Windows::Foundation::IAsyncOperation<_T>^);
_TypeSelectorAsyncAction _AsyncOperationKindSelector(Windows::Foundation::IAsyncAction^);
template <typename _T1, typename _T2>
_TypeSelectorAsyncOperationWithProgress _AsyncOperationKindSelector(Windows::Foundation::IAsyncOperationWithProgress<_T1, _T2>^);
template <typename _T>
_TypeSelectorAsyncActionWithProgress _AsyncOperationKindSelector(Windows::Foundation::IAsyncActionWithProgress<_T>^);
template <typename _Type, bool _IsAsync = _IsIAsyncInfo<_Type>::_Value>
struct _TaskTypeTraits
{
typedef typename _UnwrapTaskType<_Type>::_Type _TaskRetType;
typedef decltype(_AsyncOperationKindSelector(stdx::declval<_Type>())) _AsyncKind;
typedef typename _NormalizeVoidToUnitType<_TaskRetType>::_Type _NormalizedTaskRetType;
static const bool _IsAsyncTask = _IsAsync;
static const bool _IsUnwrappedTaskOrAsync = _IsUnwrappedAsyncSelector<_AsyncKind>::_Value;
};
template<typename _Type>
struct _TaskTypeTraits<_Type, true >
{
typedef decltype(((_Type)nullptr)->GetResults()) _TaskRetType;
typedef _TaskRetType _NormalizedTaskRetType;
typedef decltype(_AsyncOperationKindSelector((_Type)nullptr)) _AsyncKind;
static const bool _IsAsyncTask = true;
static const bool _IsUnwrappedTaskOrAsync = _IsUnwrappedAsyncSelector<_AsyncKind>::_Value;
};
#else /* defined (__cplusplus_winrt) */
template <typename _Type>
struct _IsIAsyncInfo
{
static const bool _Value = false;
};
template <typename _Type, bool _IsAsync = false>
struct _TaskTypeTraits
{
typedef typename _UnwrapTaskType<_Type>::_Type _TaskRetType;
typedef decltype(_AsyncOperationKindSelector(stdx::declval<_Type>())) _AsyncKind;
typedef typename _NormalizeVoidToUnitType<_TaskRetType>::_Type _NormalizedTaskRetType;
static const bool _IsAsyncTask = false;
static const bool _IsUnwrappedTaskOrAsync = _IsUnwrappedAsyncSelector<_AsyncKind>::_Value;
};
#endif /* defined (__cplusplus_winrt) */
template <typename _Function> auto _IsCallable(_Function _Func, int) -> decltype(_Func(), std::true_type()) { (_Func); return std::true_type(); }
template <typename _Function> std::false_type _IsCallable(_Function, ...) { return std::false_type(); }
template <>
struct _TaskTypeTraits<void>
{
typedef void _TaskRetType;
typedef _TypeSelectorNoAsync _AsyncKind;
typedef _Unit_type _NormalizedTaskRetType;
static const bool _IsAsyncTask = false;
static const bool _IsUnwrappedTaskOrAsync = false;
};
template<typename _Type>
task<_Type> _To_task(_Type t);
task<void> _To_task();
struct _BadContinuationParamType{};
template <typename _Function, typename _Type> auto _ReturnTypeHelper(_Type t, _Function _Func, int, int) -> decltype(_Func(_To_task(t)));
template <typename _Function, typename _Type> auto _ReturnTypeHelper(_Type t, _Function _Func, int, ...) -> decltype(_Func(t));
template <typename _Function, typename _Type> auto _ReturnTypeHelper(_Type t, _Function _Func, ...) -> _BadContinuationParamType;
template <typename _Function, typename _Type> auto _IsTaskHelper(_Type t, _Function _Func, int, int) -> decltype(_Func(_To_task(t)), std::true_type());
template <typename _Function, typename _Type> std::false_type _IsTaskHelper(_Type t, _Function _Func, int, ...);
template <typename _Function> auto _VoidReturnTypeHelper(_Function _Func, int, int) -> decltype(_Func(_To_task()));
template <typename _Function> auto _VoidReturnTypeHelper(_Function _Func, int, ...) -> decltype(_Func());
template <typename _Function> auto _VoidIsTaskHelper(_Function _Func, int, int) -> decltype(_Func(_To_task()), std::true_type());
template <typename _Function> std::false_type _VoidIsTaskHelper(_Function _Func, int, ...);
template<typename _Function, typename _ExpectedParameterType>
struct _FunctionTypeTraits
{
typedef decltype(_ReturnTypeHelper(stdx::declval<_ExpectedParameterType>(),stdx::declval<_Function>(), 0, 0)) _FuncRetType;
static_assert(!std::is_same<_FuncRetType,_BadContinuationParamType>::value, "incorrect parameter type for the callable object in 'then'; consider _ExpectedParameterType or task<_ExpectedParameterType> (see below)");
typedef decltype(_IsTaskHelper(stdx::declval<_ExpectedParameterType>(),stdx::declval<_Function>(), 0, 0)) _Takes_task;
};
template<typename _Function>
struct _FunctionTypeTraits<_Function, void>
{
typedef decltype(_VoidReturnTypeHelper(stdx::declval<_Function>(), 0, 0)) _FuncRetType;
typedef decltype(_VoidIsTaskHelper(stdx::declval<_Function>(), 0, 0)) _Takes_task;
};
template<typename _Function, typename _ReturnType>
struct _ContinuationTypeTraits
{
typedef task<typename _TaskTypeTraits<typename _FunctionTypeTraits<_Function, _ReturnType>::_FuncRetType>::_TaskRetType> _TaskOfType;
};
// _InitFunctorTypeTraits is used to decide whether a task constructed with a lambda should be unwrapped. Depending on how the variable is
// declared, the constructor may or may not perform unwrapping. For eg.
//
// This declaration SHOULD NOT cause unwrapping
// task<task<void>> t1([]() -> task<void> {
// task<void> t2([]() {});
// return t2;
// });
//
// This declaration SHOULD cause unwrapping
// task<void>> t1([]() -> task<void> {
// task<void> t2([]() {});
// return t2;
// });
// If the type of the task is the same as the return type of the function, no unwrapping should take place. Else normal rules apply.
template <typename _TaskType, typename _FuncRetType>
struct _InitFunctorTypeTraits
{
typedef typename _TaskTypeTraits<_FuncRetType>::_AsyncKind _AsyncKind;
static const bool _IsAsyncTask = _TaskTypeTraits<_FuncRetType>::_IsAsyncTask;
static const bool _IsUnwrappedTaskOrAsync = _TaskTypeTraits<_FuncRetType>::_IsUnwrappedTaskOrAsync;
};
template<typename T>
struct _InitFunctorTypeTraits<T, T>
{
typedef _TypeSelectorNoAsync _AsyncKind;
static const bool _IsAsyncTask = false;
static const bool _IsUnwrappedTaskOrAsync = false;
};
/// <summary>
/// Helper object used for LWT invocation.
/// </summary>
struct _TaskProcThunk
{
_TaskProcThunk(const std::function<void ()> & _Callback) :
_M_func(_Callback)
{
}
static void __cdecl _Bridge(void *_PData)
{
_TaskProcThunk *_PThunk = reinterpret_cast<_TaskProcThunk *>(_PData);
_Holder _ThunkHolder(_PThunk);
_PThunk->_M_func();
}
private:
// RAII holder
struct _Holder
{
_Holder(_TaskProcThunk * _PThunk) : _M_pThunk(_PThunk)
{
}
~_Holder()
{
delete _M_pThunk;
}
_TaskProcThunk * _M_pThunk;
private:
_Holder& operator=(const _Holder&);
};
std::function<void()> _M_func;
_TaskProcThunk& operator=(const _TaskProcThunk&);
};
/// <summary>
/// Schedule a functor with automatic inlining. Note that this is "fire and forget" scheduling, which cannot be
/// waited on or canceled after scheduling.
/// This schedule method will perform automatic inlining base on <paramref value="_InliningMode"/>.
/// </summary>
/// <param name="_Func">
/// The user functor need to be scheduled.
/// </param>
/// <param name="_InliningMode">
/// The inlining scheduling policy for current functor.
/// </param>
static void _ScheduleFuncWithAutoInline(const std::function<void ()> & _Func, _TaskInliningMode_t _InliningMode)
{
_TaskCollection_t::_RunTask(&_TaskProcThunk::_Bridge, new _TaskProcThunk(_Func), _InliningMode);
}
class _ContextCallback
{
typedef std::function<void(void)> _CallbackFunction;
#if defined (__cplusplus_winrt)
public:
static _ContextCallback _CaptureCurrent()
{
_ContextCallback _Context;
_Context._Capture();
return _Context;
}
~_ContextCallback()
{
_Reset();
}
_ContextCallback(bool _DeferCapture = false)
{
if (_DeferCapture)
{
_M_context._M_captureMethod = _S_captureDeferred;
}
else
{
_M_context._M_pContextCallback = nullptr;
}
}
// Resolves a context that was created as _S_captureDeferred based on the environment (ancestor, current context).
void _Resolve(bool _CaptureCurrent)
{
if(_M_context._M_captureMethod == _S_captureDeferred)
{
_M_context._M_pContextCallback = nullptr;
if (_CaptureCurrent)
{
if (_IsCurrentOriginSTA())
{
_Capture();
}
#if _UITHREADCTXT_SUPPORT
else
{
// This method will fail if not called from the UI thread.
HRESULT _Hr = CaptureUiThreadContext(&_M_context._M_pContextCallback);
if (FAILED(_Hr))
{
_M_context._M_pContextCallback = nullptr;
}
}
#endif /* _UITHREADCTXT_SUPPORT */
}
}
}
void _Capture()
{
HRESULT _Hr = CoGetObjectContext(IID_IContextCallback, reinterpret_cast<void **>(&_M_context._M_pContextCallback));
if (FAILED(_Hr))
{
_M_context._M_pContextCallback = nullptr;
}
}
_ContextCallback(const _ContextCallback& _Src)
{
_Assign(_Src._M_context._M_pContextCallback);
}
_ContextCallback(_ContextCallback&& _Src)
{
_M_context._M_pContextCallback = _Src._M_context._M_pContextCallback;
_Src._M_context._M_pContextCallback = nullptr;
}
_ContextCallback& operator=(const _ContextCallback& _Src)
{
if (this != &_Src)
{
_Reset();
_Assign(_Src._M_context._M_pContextCallback);
}
return *this;
}
_ContextCallback& operator=(_ContextCallback&& _Src)
{
if (this != &_Src)
{
_M_context._M_pContextCallback = _Src._M_context._M_pContextCallback;
_Src._M_context._M_pContextCallback = nullptr;
}
return *this;
}
bool _HasCapturedContext() const
{
_ASSERTE(_M_context._M_captureMethod != _S_captureDeferred);
return (_M_context._M_pContextCallback != nullptr);
}
void _CallInContext(_CallbackFunction _Func) const
{
if (!_HasCapturedContext())
{
_Func();
}
else
{
ComCallData callData;
ZeroMemory(&callData, sizeof(callData));
callData.pUserDefined = reinterpret_cast<void *>(&_Func);
HRESULT _Hr = _M_context._M_pContextCallback->ContextCallback(&_Bridge, &callData, IID_ICallbackWithNoReentrancyToApplicationSTA, 5, nullptr);
if (FAILED(_Hr))
{
throw ::Platform::Exception::CreateException(_Hr);
}
}
}
bool operator==(const _ContextCallback& _Rhs) const
{
return (_M_context._M_pContextCallback == _Rhs._M_context._M_pContextCallback);
}
bool operator!=(const _ContextCallback& _Rhs) const
{
return !(operator==(_Rhs));
}
private:
void _Reset()
{
if (_M_context._M_captureMethod != _S_captureDeferred && _M_context._M_pContextCallback != nullptr)
{
_M_context._M_pContextCallback->Release();
}
}
void _Assign(IContextCallback *_PContextCallback)
{
_M_context._M_pContextCallback = _PContextCallback;
if (_M_context._M_captureMethod != _S_captureDeferred && _M_context._M_pContextCallback != nullptr)
{
_M_context._M_pContextCallback->AddRef();
}
}
static HRESULT __stdcall _Bridge(ComCallData *_PParam)
{
_CallbackFunction *pFunc = reinterpret_cast<_CallbackFunction *>(_PParam->pUserDefined);
(*pFunc)();
return S_OK;
}
// Returns the origin information for the caller (runtime / Windows Runtime apartment as far as task continuations need know)
static bool _IsCurrentOriginSTA()
{
APTTYPE _AptType;
APTTYPEQUALIFIER _AptTypeQualifier;
HRESULT hr = CoGetApartmentType(&_AptType, &_AptTypeQualifier);
if (SUCCEEDED(hr))
{
// We determine the origin of a task continuation by looking at where .then is called, so we can tell whether
// to need to marshal the continuation back to the originating apartment. If an STA thread is in executing in
// a neutral aparment when it schedules a continuation, we will not marshal continuations back to the STA,
// since variables used within a neutral apartment are expected to be apartment neutral.
switch(_AptType)
{
case APTTYPE_MAINSTA:
case APTTYPE_STA:
return true;
default:
break;
}
}
return false;
}
union
{
IContextCallback *_M_pContextCallback;
size_t _M_captureMethod;
} _M_context;
static const size_t _S_captureDeferred = 1;
#else /* defined (__cplusplus_winrt) */
public:
static _ContextCallback _CaptureCurrent()
{
return _ContextCallback();
}
_ContextCallback(bool = false)
{
}
_ContextCallback(const _ContextCallback&)
{
}
_ContextCallback(_ContextCallback&&)
{
}
_ContextCallback& operator=(const _ContextCallback&)
{
return *this;
}
_ContextCallback& operator=(_ContextCallback&&)
{
return *this;
}
bool _HasCapturedContext() const
{
return false;
}
void _Resolve(bool) const
{
}
void _CallInContext(_CallbackFunction _Func) const
{
_Func();
}
bool operator==(const _ContextCallback&) const
{
return true;
}
bool operator!=(const _ContextCallback&) const
{
return false;
}
#endif /* defined (__cplusplus_winrt) */
};
template<typename _Type>
struct _ResultHolder
{
void Set(const _Type& _type)
{
_Result = _type;
}
_Type Get()
{
return _Result;
}
_Type _Result;
};
#if defined (__cplusplus_winrt)
template<typename _Type>
struct _ResultHolder<_Type^>
{
void Set(_Type^ const & _type)
{
_M_Result = _type;
}
_Type^ Get()
{
return _M_Result.Get();
}
private:
// ::Platform::Agile handle specialization of all hats
// including ::Platform::String and ::Platform::Array
::Platform::Agile<_Type^> _M_Result;
};
//
// The below are for composability with tasks auto-created from when_any / when_all / && / || constructs.
//
template<typename _Type>
struct _ResultHolder<std::vector<_Type^>>
{
void Set(const std::vector<_Type^>& _type)
{
_Result.reserve(_type.size());
for (auto _PTask = _type.begin(); _PTask != _type.end(); ++_PTask)
{
_Result.emplace_back(*_PTask);
}
}
std::vector<_Type^> Get()
{
// Return vectory<T^> with the objects that are marshaled in the proper appartment
std::vector<_Type^> _Return;
_Return.reserve(_Result.size());
for (auto _PTask = _Result.begin(); _PTask != _Result.end(); ++_PTask)
{
_Return.push_back(_PTask->Get()); // Platform::Agile will marshal the object to appropriate appartment if neccessary
}
return _Return;
}
std::vector< ::Platform::Agile<_Type^> > _Result;
};
template<typename _Type>
struct _ResultHolder<std::pair<_Type^, void*> >
{
void Set(const std::pair<_Type^, size_t>& _type)
{
_M_Result = _type;
}
std::pair<_Type^, size_t> Get()
{
return std::make_pair(_M_Result.first.Get(), _M_Result.second);
}
private:
std::pair< ::Platform::Agile<_Type^>, size_t> _M_Result;
};
#endif /* defined (__cplusplus_winrt) */
// An exception thrown by the task body is captured in an exception holder and it is shared with all value based continuations rooted at the task.
// The exception is 'observed' if the user invokes get()/wait() on any of the tasks that are sharing this exception holder. If the exception
// is not observed by the time the internal object owned by the shared pointer destructs, the process will fail fast.
struct _ExceptionHolder
{
private:
void ReportUnhandledError()
{
#if defined (__cplusplus_winrt)
if (_M_winRTException != nullptr)
{
::Platform::Details::ReportUnhandledError(_M_winRTException);
}
#endif /* defined (__cplusplus_winrt) */
}
public:
explicit _ExceptionHolder(const std::exception_ptr& _E, const _TaskCreationCallstack &_stackTrace) :
_M_exceptionObserved(0), _M_stdException(_E), _M_stackTrace(_stackTrace)
#if defined (__cplusplus_winrt)
, _M_winRTException(nullptr)
#endif /* defined (__cplusplus_winrt) */
{
}
#if defined (__cplusplus_winrt)
explicit _ExceptionHolder(::Platform::Exception^ _E, const _TaskCreationCallstack &_stackTrace) :
_M_exceptionObserved(0), _M_winRTException(_E), _M_stackTrace(_stackTrace)
{
}
#endif /* defined (__cplusplus_winrt) */
__declspec(noinline)
~_ExceptionHolder()
{
if (_M_exceptionObserved == 0)
{
// If you are trapped here, it means an exception thrown in task chain didn't get handled.
// Please add task-based continuation to handle all exceptions coming from tasks.
// this->_M_stackTrace keeps the creation callstack of the task generates this exception.
_REPORT_PPLTASK_UNOBSERVED_EXCEPTION();
}
}
void _RethrowUserException()
{
if (_M_exceptionObserved == 0)
{
atomic_exchange(_M_exceptionObserved, 1l);
}
#if defined (__cplusplus_winrt)
if (_M_winRTException != nullptr)
{
throw _M_winRTException;
}
#endif /* defined (__cplusplus_winrt) */
std::rethrow_exception(_M_stdException);
}
// A variable that remembers if this exception was every rethrown into user code (and hence handled by the user). Exceptions that
// are unobserved when the exception holder is destructed will terminate the process.
atomic_long _M_exceptionObserved;
// Either _M_stdException or _M_winRTException is populated based on the type of exception encountered.
std::exception_ptr _M_stdException;
#if defined (__cplusplus_winrt)
::Platform::Exception^ _M_winRTException;
#endif /* defined (__cplusplus_winrt) */
// Disassembling this value will point to a source instruction right after a call instruction. If the call is to create_task,
// a task constructor or the then method, the task created by that method is the one that encountered this exception. If the call
// is to task_completion_event::set_exception, the set_exception method was the source of the exception.
// DO NOT REMOVE THIS VARIABLE. It is extremely helpful for debugging.
_TaskCreationCallstack _M_stackTrace;
};
#if defined (__cplusplus_winrt)
/// <summary>
/// Base converter class for converting asynchronous interfaces to IAsyncOperation
/// </summary>
template<typename _AsyncOperationType, typename _CompletionHandlerType, typename _Result>
ref struct _AsyncInfoImpl abstract : Windows::Foundation::IAsyncOperation<_Result>
{
internal:
// The async action, action with progress or operation with progress that this stub forwards to.
::Platform::Agile<_AsyncOperationType> _M_asyncInfo;
Windows::Foundation::AsyncOperationCompletedHandler<_Result>^ _M_CompletedHandler;
_AsyncInfoImpl( _AsyncOperationType _AsyncInfo ) : _M_asyncInfo(_AsyncInfo) {}
public:
virtual void Cancel() { _M_asyncInfo.Get()->Cancel(); }
virtual void Close() { _M_asyncInfo.Get()->Close(); }
virtual property Windows::Foundation::HResult ErrorCode
{
Windows::Foundation::HResult get()
{
return _M_asyncInfo.Get()->ErrorCode;
}
}
virtual property UINT Id
{
UINT get()
{
return _M_asyncInfo.Get()->Id;
}
}
virtual property Windows::Foundation::AsyncStatus Status
{
Windows::Foundation::AsyncStatus get()
{
return _M_asyncInfo.Get()->Status;
}
}
virtual _Result GetResults() { throw std::runtime_error("derived class must implement"); }
virtual property Windows::Foundation::AsyncOperationCompletedHandler<_Result>^ Completed
{
Windows::Foundation::AsyncOperationCompletedHandler<_Result>^ get()
{
return _M_CompletedHandler;
}
void set(Windows::Foundation::AsyncOperationCompletedHandler<_Result>^ value)
{
_M_CompletedHandler = value;
_M_asyncInfo.Get()->Completed = ref new _CompletionHandlerType([&](_AsyncOperationType, Windows::Foundation::AsyncStatus status) {
_M_CompletedHandler->Invoke(this, status);
});
}
}
};
/// <summary>
/// Class _IAsyncOperationWithProgressToAsyncOperationConverter is used to convert an instance of IAsyncOperationWithProgress<T> into IAsyncOperation<T>
/// </summary>
template<typename _Result, typename _Progress>
ref struct _IAsyncOperationWithProgressToAsyncOperationConverter sealed :
_AsyncInfoImpl<Windows::Foundation::IAsyncOperationWithProgress<_Result,_Progress>^,
Windows::Foundation::AsyncOperationWithProgressCompletedHandler<_Result,_Progress>,
_Result>
{
internal:
_IAsyncOperationWithProgressToAsyncOperationConverter(Windows::Foundation::IAsyncOperationWithProgress<_Result,_Progress>^ _Operation) :
_AsyncInfoImpl<Windows::Foundation::IAsyncOperationWithProgress<_Result,_Progress>^,
Windows::Foundation::AsyncOperationWithProgressCompletedHandler<_Result,_Progress>,
_Result>(_Operation) {}
public:
virtual _Result GetResults() override { return _M_asyncInfo.Get()->GetResults(); }
};
/// <summary>
/// Class _IAsyncActionToAsyncOperationConverter is used to convert an instance of IAsyncAction into IAsyncOperation<_Unit_type>
/// </summary>
ref struct _IAsyncActionToAsyncOperationConverter sealed :
_AsyncInfoImpl<Windows::Foundation::IAsyncAction^,
Windows::Foundation::AsyncActionCompletedHandler,
details::_Unit_type>
{
internal:
_IAsyncActionToAsyncOperationConverter(Windows::Foundation::IAsyncAction^ _Operation) :
_AsyncInfoImpl<Windows::Foundation::IAsyncAction^,
Windows::Foundation::AsyncActionCompletedHandler,
details::_Unit_type>(_Operation) {}
public:
virtual details::_Unit_type GetResults() override
{
// Invoke GetResults on the IAsyncAction to allow exceptions to be thrown to higher layers before returning a dummy value.
_M_asyncInfo.Get()->GetResults();
return details::_Unit_type();
}
};
/// <summary>
/// Class _IAsyncActionWithProgressToAsyncOperationConverter is used to convert an instance of IAsyncActionWithProgress into IAsyncOperation<_Unit_type>
/// </summary>
template<typename _Progress>
ref struct _IAsyncActionWithProgressToAsyncOperationConverter sealed :
_AsyncInfoImpl<Windows::Foundation::IAsyncActionWithProgress<_Progress>^,
Windows::Foundation::AsyncActionWithProgressCompletedHandler<_Progress>,
details::_Unit_type>
{
internal:
_IAsyncActionWithProgressToAsyncOperationConverter(Windows::Foundation::IAsyncActionWithProgress<_Progress>^ _Action) :
_AsyncInfoImpl<Windows::Foundation::IAsyncActionWithProgress<_Progress>^,
Windows::Foundation::AsyncActionWithProgressCompletedHandler<_Progress>,
details::_Unit_type>(_Action) {}
public:
virtual details::_Unit_type GetResults() override
{
// Invoke GetResults on the IAsyncActionWithProgress to allow exceptions to be thrown before returning a dummy value.
_M_asyncInfo.Get()->GetResults();
return details::_Unit_type();
}
};
#endif /* defined (__cplusplus_winrt) */
} // namespace details
/// <summary>
/// The <c>task_continuation_context</c> class allows you to specify where you would like a continuation to be executed.
/// It is only useful to use this class from a Windows Store app. For non-Windows Store apps, the task continuation's
/// execution context is determined by the runtime, and not configurable.
/// </summary>
/// <seealso cref="task Class"/>
/**/
class task_continuation_context : public details::_ContextCallback
{
public:
/// <summary>
/// Creates the default task continuation context.
/// </summary>
/// <returns>
/// The default continuation context.
/// </returns>
/// <remarks>
/// The default context is used if you don't specifiy a continuation context when you call the <c>then</c> method. In Windows
/// applications for Windows 7 and below, as well as desktop applications on Windows 8 and higher, the runtime determines where
/// task continuations will execute. However, in a Windows Store app, the default continuation context for a continuation on an
/// apartment aware task is the apartment where <c>then</c> is invoked.
/// <para>An apartment aware task is a task that unwraps a Windows Runtime <c>IAsyncInfo</c> interface, or a task that is descended from such
/// a task. Therefore, if you schedule a continuation on an apartment aware task in a Windows Runtime STA, the continuation will execute in
/// that STA.</para>
/// <para>A continuation on a non-apartment aware task will execute in a context the Runtime chooses.</para>
/// </remarks>
/**/
static task_continuation_context use_default()
{
#if defined (__cplusplus_winrt)
// The callback context is created with the context set to CaptureDeferred and resolved when it is used in .then()
return task_continuation_context(true); // sets it to deferred, is resolved in the constructor of _ContinuationTaskHandle
#else /* defined (__cplusplus_winrt) */
return task_continuation_context();
#endif /* defined (__cplusplus_winrt) */
}
#if defined (__cplusplus_winrt)
/// <summary>
/// Creates a task continuation context which allows the Runtime to choose the execution context for a continuation.
/// </summary>
/// <returns>
/// A task continuation context that represents an arbitrary location.
/// </returns>
/// <remarks>
/// When this continuation context is used the continuation will execute in a context the runtime chooses even if the antecedent task
/// is apartment aware.
/// <para><c>use_arbitrary</c> can be used to turn off the default behavior for a continuation on an apartment
/// aware task created in an STA. </para>
/// <para>This method is only available to Windows Store apps.</para>
/// </remarks>
/**/
static task_continuation_context use_arbitrary()
{
task_continuation_context _Arbitrary(true);
_Arbitrary._Resolve(false);
return _Arbitrary;
}
/// <summary>
/// Returns a task continuation context object that represents the current execution context.
/// </summary>
/// <returns>
/// The current execution context.
/// </returns>
/// <remarks>
/// This method captures the caller's Windows Runtime context so that continuations can be executed in the right apartment.
/// <para>The value returned by <c>use_current</c> can be used to indicate to the Runtime that the continuation should execute in
/// the captured context (STA vs MTA) regardless of whether or not the antecedent task is apartment aware. An apartment aware task is
/// a task that unwraps a Windows Runtime <c>IAsyncInfo</c> interface, or a task that is descended from such a task. </para>
/// <para>This method is only available to Windows Store apps.</para>
/// </remarks>
/**/
static task_continuation_context use_current()
{
task_continuation_context _Current(true);
_Current._Resolve(true);
return _Current;
}
#endif /* defined (__cplusplus_winrt) */
private:
task_continuation_context(bool _DeferCapture = false) : details::_ContextCallback(_DeferCapture)
{
}
};
class task_options;
namespace details
{
struct _Internal_task_options
{
bool _M_hasPresetCreationCallstack;
_TaskCreationCallstack _M_presetCreationCallstack;
void _set_creation_callstack(const _TaskCreationCallstack &_callstack)
{
_M_hasPresetCreationCallstack = true;
_M_presetCreationCallstack = _callstack;
}
_Internal_task_options()
{
_M_hasPresetCreationCallstack = false;
}
};
inline _Internal_task_options &_get_internal_task_options(task_options &options);
inline const _Internal_task_options &_get_internal_task_options(const task_options &options);
}
/// <summary>
/// Represents the allowed options for creating a task
/// </summary>
class task_options
{
public:
/// <summary>
/// Default list of task creation options
/// </summary>
task_options()
: _M_Scheduler(get_ambient_scheduler()),
_M_CancellationToken(cancellation_token::none()),
_M_ContinuationContext(task_continuation_context::use_default()),
_M_HasCancellationToken(false),
_M_HasScheduler(false)
{
}
/// <summary>
/// Task option that specify a cancellation token
/// </summary>
task_options(cancellation_token _Token)
: _M_Scheduler(get_ambient_scheduler()),
_M_CancellationToken(_Token),
_M_ContinuationContext(task_continuation_context::use_default()),
_M_HasCancellationToken(true),
_M_HasScheduler(false)
{
}
/// <summary>
/// Task option that specify a continuation context. This is valid only for continuations (then)
/// </summary>
task_options(task_continuation_context _ContinuationContext)
: _M_Scheduler(get_ambient_scheduler()),
_M_CancellationToken(cancellation_token::none()),
_M_ContinuationContext(_ContinuationContext),
_M_HasCancellationToken(false),
_M_HasScheduler(false)
{
}
/// <summary>
/// Task option that specify a cancellation token and a continuation context. This is valid only for continuations (then)
/// </summary>
task_options(cancellation_token _Token, task_continuation_context _ContinuationContext)
: _M_Scheduler(get_ambient_scheduler()),
_M_CancellationToken(_Token),
_M_ContinuationContext(_ContinuationContext),
_M_HasCancellationToken(false),
_M_HasScheduler(false)
{
}
/// <summary>
/// Task option that specify a scheduler with shared lifetime
/// </summary>
template<typename _SchedType>
task_options(std::shared_ptr<_SchedType> _Scheduler)
: _M_Scheduler(std::move(_Scheduler)),
_M_CancellationToken(cancellation_token::none()),
_M_ContinuationContext(task_continuation_context::use_default()),
_M_HasCancellationToken(false),
_M_HasScheduler(true)
{
}
/// <summary>
/// Task option that specify a scheduler reference
/// </summary>
task_options(scheduler_interface& _Scheduler)
: _M_Scheduler(&_Scheduler),
_M_CancellationToken(cancellation_token::none()),
_M_ContinuationContext(task_continuation_context::use_default()),
_M_HasCancellationToken(false),
_M_HasScheduler(true)
{
}
/// <summary>
/// Task option that specify a scheduler
/// </summary>
task_options(scheduler_ptr _Scheduler)
: _M_Scheduler(std::move(_Scheduler)),
_M_CancellationToken(cancellation_token::none()),
_M_ContinuationContext(task_continuation_context::use_default()),
_M_HasCancellationToken(false),
_M_HasScheduler(true)
{
}
/// <summary>
/// Task option copy constructor
/// </summary>
task_options(const task_options& _TaskOptions)
: _M_Scheduler(_TaskOptions.get_scheduler()),
_M_CancellationToken(_TaskOptions.get_cancellation_token()),
_M_ContinuationContext(_TaskOptions.get_continuation_context()),
_M_HasCancellationToken(_TaskOptions.has_cancellation_token()),
_M_HasScheduler(_TaskOptions.has_scheduler())
{
}
/// <summary>
/// Sets the given token in the options
/// </summary>
void set_cancellation_token(cancellation_token _Token)
{
_M_CancellationToken = _Token;
_M_HasCancellationToken = true;
}
/// <summary>
/// Sets the given continuation context in the options
/// </summary>
void set_continuation_context(task_continuation_context _ContinuationContext)
{
_M_ContinuationContext = _ContinuationContext;
}
/// <summary>
/// Indicates whether a cancellation token was specified by the user
/// </summary>
bool has_cancellation_token() const
{
return _M_HasCancellationToken;
}
/// <summary>
/// Returns the cancellation token
/// </summary>
cancellation_token get_cancellation_token() const
{
return _M_CancellationToken;
}
/// <summary>
/// Returns the continuation context
/// </summary>
task_continuation_context get_continuation_context() const
{
return _M_ContinuationContext;
}
/// <summary>
/// Indicates whether a scheduler n was specified by the user
/// </summary>
bool has_scheduler() const
{
return _M_HasScheduler;
}
/// <summary>
/// Returns the scheduler
/// </summary>
scheduler_ptr get_scheduler() const
{
return _M_Scheduler;
}
private:
task_options const& operator=(task_options const& _Right);
friend details::_Internal_task_options &details::_get_internal_task_options(task_options &);
friend const details::_Internal_task_options &details::_get_internal_task_options(const task_options &);
scheduler_ptr _M_Scheduler;
cancellation_token _M_CancellationToken;
task_continuation_context _M_ContinuationContext;
details::_Internal_task_options _M_InternalTaskOptions;
bool _M_HasCancellationToken;
bool _M_HasScheduler;
};
namespace details
{
inline _Internal_task_options & _get_internal_task_options(task_options &options)
{
return options._M_InternalTaskOptions;
}
inline const _Internal_task_options & _get_internal_task_options(const task_options &options)
{
return options._M_InternalTaskOptions;
}
struct _Task_impl_base;
template<typename _ReturnType> struct _Task_impl;
template<typename _ReturnType>
struct _Task_ptr
{
typedef std::shared_ptr<_Task_impl<_ReturnType>> _Type;
static _Type _Make(_CancellationTokenState * _Ct, scheduler_ptr _Scheduler_arg) { return std::make_shared<_Task_impl<_ReturnType>>(_Ct, _Scheduler_arg); }
};
typedef _TaskCollection_t::_TaskProcHandle_t _UnrealizedChore_t;
typedef std::shared_ptr<_Task_impl_base> _Task_ptr_base;
// The weak-typed base task handler for continuation tasks.
struct _ContinuationTaskHandleBase : _UnrealizedChore_t
{
_ContinuationTaskHandleBase * _M_next;
task_continuation_context _M_continuationContext;
bool _M_isTaskBasedContinuation;
// This field gives inlining scheduling policy for current chore.
_TaskInliningMode_t _M_inliningMode;
virtual _Task_ptr_base _GetTaskImplBase() const = 0;
_ContinuationTaskHandleBase() :
_M_next(nullptr), _M_continuationContext(task_continuation_context::use_default()), _M_isTaskBasedContinuation(false), _M_inliningMode(details::_NoInline)
{
}
virtual ~_ContinuationTaskHandleBase() {}
};
#if _PPLTASK_ASYNC_LOGGING
// GUID used for identifying causality logs from PPLTask
const ::Platform::Guid _PPLTaskCausalityPlatformID(0x7A76B220, 0xA758, 0x4E6E, 0xB0, 0xE0, 0xD7, 0xC6, 0xD7, 0x4A, 0x88, 0xFE);
__declspec(selectany) volatile long _isCausalitySupported = 0;
inline bool _IsCausalitySupported()
{
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
if (_isCausalitySupported == 0)
{
long _causality = 1;
OSVERSIONINFOEX _osvi = {};
_osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
// The Causality is supported on Windows version higher than Windows 8
_osvi.dwMajorVersion = 6;
_osvi.dwMinorVersion = 3;
DWORDLONG _conditionMask = 0;
VER_SET_CONDITION( _conditionMask, VER_MAJORVERSION, VER_GREATER_EQUAL );
VER_SET_CONDITION( _conditionMask, VER_MINORVERSION, VER_GREATER_EQUAL );
if ( ::VerifyVersionInfo(&_osvi, VER_MAJORVERSION | VER_MINORVERSION, _conditionMask))
{
_causality = 2;
}
_isCausalitySupported = _causality;
return _causality == 2;
}
return _isCausalitySupported == 2 ? true : false;
#else
return true;
#endif
}
// Stateful logger rests inside task_impl_base.
struct _TaskEventLogger
{
_Task_impl_base *_M_task;
bool _M_scheduled;
bool _M_taskPostEventStarted;
// Log before scheduling task
void _LogScheduleTask(bool _isContinuation)
{
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceOperationCreation(::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required, ::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID, reinterpret_cast<unsigned long long>(_M_task),
_isContinuation ? "Concurrency::PPLTask::ScheduleContinuationTask" : "Concurrency::PPLTask::ScheduleTask", 0);
_M_scheduled = true;
}
}
// It will log the cancel event but not canceled state. _LogTaskCompleted will log the terminal state, which includes cancel state.
void _LogCancelTask()
{
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceOperationRelation(::Windows::Foundation::Diagnostics::CausalityTraceLevel::Important, ::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID, reinterpret_cast<unsigned long long>(_M_task), ::Windows::Foundation::Diagnostics::CausalityRelation::Cancel);
}
}
// Log when task reaches terminal state. Note: the task can reach a terminal state (by cancellation or exception) without having run
void _LogTaskCompleted();
// Log when task body (which includes user lambda and other scheduling code) begin to run
void _LogTaskExecutionStarted() { }
// Log when task body finish executing
void _LogTaskExecutionCompleted()
{
if (_M_taskPostEventStarted && details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceSynchronousWorkCompletion(::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required, ::Windows::Foundation::Diagnostics::CausalitySource::Library,
::Windows::Foundation::Diagnostics::CausalitySynchronousWork::CompletionNotification);
}
}
// Log right before user lambda being invoked
void _LogWorkItemStarted()
{
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceSynchronousWorkStart(::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required, ::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID, reinterpret_cast<unsigned long long>(_M_task), ::Windows::Foundation::Diagnostics::CausalitySynchronousWork::Execution);
}
}
// Log right after user lambda being invoked
void _LogWorkItemCompleted()
{
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceSynchronousWorkCompletion(::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required, ::Windows::Foundation::Diagnostics::CausalitySource::Library,
::Windows::Foundation::Diagnostics::CausalitySynchronousWork::Execution);
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceSynchronousWorkStart(::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required, ::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID, reinterpret_cast<unsigned long long>(_M_task), ::Windows::Foundation::Diagnostics::CausalitySynchronousWork::CompletionNotification);
_M_taskPostEventStarted = true;
}
}
_TaskEventLogger(_Task_impl_base *_task): _M_task(_task)
{
_M_scheduled = false;
_M_taskPostEventStarted = false;
}
};
// Exception safe logger for user lambda
struct _TaskWorkItemRAIILogger
{
_TaskEventLogger &_M_logger;
_TaskWorkItemRAIILogger(_TaskEventLogger &_taskHandleLogger): _M_logger(_taskHandleLogger)
{
_M_logger._LogWorkItemStarted();
}
~_TaskWorkItemRAIILogger()
{
_M_logger._LogWorkItemCompleted();
}
_TaskWorkItemRAIILogger &operator =(const _TaskWorkItemRAIILogger &); // cannot be assigned
};
#else
inline void _LogCancelTask(_Task_impl_base *) {}
struct _TaskEventLogger
{
void _LogScheduleTask(bool) {}
void _LogCancelTask() {}
void _LogWorkItemStarted() {}
void _LogWorkItemCompleted() {}
void _LogTaskExecutionStarted() {}
void _LogTaskExecutionCompleted() {}
void _LogTaskCompleted() {}
_TaskEventLogger(_Task_impl_base *) {}
};
struct _TaskWorkItemRAIILogger
{
_TaskWorkItemRAIILogger(_TaskEventLogger &) {}
};
#endif
/// <summary>
/// The _PPLTaskHandle is the strong-typed task handle base. All user task functions need to be wrapped in this task handler
/// to be executable by PPL. By deriving from a different _BaseTaskHandle, it can be used for both initial tasks and continuation tasks.
/// For initial tasks, _PPLTaskHandle will be derived from _UnrealizedChore_t, and for continuation tasks, it will be derived from
/// _ContinuationTaskHandleBase. The life time of the _PPLTaskHandle object is be managed by runtime if task handle is scheduled.
/// </summary>
/// <typeparam name="_ReturnType">
/// The result type of the _Task_impl.
/// </typeparam>
/// <typeparam name="_DerivedTaskHandle">
/// The derived task handle class. The <c>operator ()</c> needs to be implemented.
/// </typeparam>
/// <typeparam name="_BaseTaskHandle">
/// The base class from which _PPLTaskHandle should be derived. This is either _UnrealizedChore_t or _ContinuationTaskHandleBase.
/// </typeparam>
template<typename _ReturnType, typename _DerivedTaskHandle, typename _BaseTaskHandle>
struct _PPLTaskHandle : _BaseTaskHandle
{
_PPLTaskHandle(const typename _Task_ptr<_ReturnType>::_Type & _PTask) : _M_pTask(_PTask)
{
}
virtual ~_PPLTaskHandle()
{
// Here is the sink of all task completion code paths
_M_pTask->_M_taskEventLogger._LogTaskCompleted();
}
virtual void invoke() const
{
// All exceptions should be rethrown to finish cleanup of the task collection. They will be caught and handled
// by the runtime.
_ASSERTE((bool)_M_pTask);
if (!_M_pTask->_TransitionedToStarted())
{
static_cast<const _DerivedTaskHandle *>(this)->_SyncCancelAndPropagateException();
return;
}
_M_pTask->_M_taskEventLogger._LogTaskExecutionStarted();
try
{
// All derived task handle must implement this contract function.
static_cast<const _DerivedTaskHandle *>(this)->_Perform();
}
catch(const task_canceled &)
{
_M_pTask->_Cancel(true);
}
catch(const _Interruption_exception &)
{
_M_pTask->_Cancel(true);
}
#if defined (__cplusplus_winrt)
catch(::Platform::Exception^ _E)
{
_M_pTask->_CancelWithException(_E);
}
#endif /* defined (__cplusplus_winrt) */
catch(...)
{
_M_pTask->_CancelWithException(std::current_exception());
}
_M_pTask->_M_taskEventLogger._LogTaskExecutionCompleted();
}
// Cast _M_pTask pointer to "type-less" _Task_impl_base pointer, which can be used in _ContinuationTaskHandleBase.
// The return value should be automatically optimized by R-value ref.
_Task_ptr_base _GetTaskImplBase() const
{
return _M_pTask;
}
typename _Task_ptr<_ReturnType>::_Type _M_pTask;
private:
_PPLTaskHandle const & operator=(_PPLTaskHandle const&); // no assignment operator
};
/// <summary>
/// The base implementation of a first-class task. This class contains all the non-type specific
/// implementation details of the task.
/// </summary>
/**/
struct _Task_impl_base
{
enum _TaskInternalState
{
// Tracks the state of the task, rather than the task collection on which the task is scheduled
_Created,
_Started,
_PendingCancel,
_Completed,
_Canceled
};
_Task_impl_base(_CancellationTokenState * _PTokenState, scheduler_ptr _Scheduler_arg)
: _M_TaskState(_Created),
_M_fFromAsync(false), _M_fUnwrappedTask(false),
_M_pRegistration(nullptr), _M_Continuations(nullptr), _M_TaskCollection(_Scheduler_arg),
_M_taskEventLogger(this)
{
// Set cancelation token
_M_pTokenState = _PTokenState;
_ASSERTE(_M_pTokenState != nullptr);
if (_M_pTokenState != _CancellationTokenState::_None())
_M_pTokenState->_Reference();
}
virtual ~_Task_impl_base()
{
_ASSERTE(_M_pTokenState != nullptr);
if (_M_pTokenState != _CancellationTokenState::_None())
{
_M_pTokenState->_Release();
}
}
task_status _Wait()
{
bool _DoWait = true;
#if defined (__cplusplus_winrt)
if (_IsNonBlockingThread())
{
// In order to prevent Windows Runtime STA threads from blocking the UI, calling task.wait() task.get() is illegal
// if task has not been completed.
if (!_IsCompleted() && !_IsCanceled())
{
throw invalid_operation("Illegal to wait on a task in a Windows Runtime STA");
}
else
{
// Task Continuations are 'scheduled' *inside* the chore that is executing on the ancestors's task group. If a continuation
// needs to be marshalled to a different apartment, instead of scheduling, we make a synchronous cross apartment COM
// call to execute the continuation. If it then happens to do something which waits on the ancestor (say it calls .get(), which
// task based continuations are wont to do), waiting on the task group results in on the chore that is making this
// synchronous callback, which causes a deadlock. To avoid this, we test the state ancestor's event , and we will NOT wait on
// if it has finished execution (which means now we are on the inline synchronous callback).
_DoWait = false;
}
}
#endif /* defined (__cplusplus_winrt) */
if (_DoWait)
{
// If this task was created from a Windows Runtime async operation, do not attempt to inline it. The
// async operation will take place on a thread in the appropriate apartment Simply wait for the completed
// event to be set.
if (_M_fFromAsync)
{
_M_TaskCollection._Wait();
}
else
{
// Wait on the task collection to complete. The task collection is guaranteed to still be
// valid since the task must be still within scope so that the _Task_impl_base destructor
// has not yet been called. This call to _Wait potentially inlines execution of work.
try
{
// Invoking wait on a task collection resets the state of the task collection. This means that
// if the task collection itself were canceled, or had encountered an exception, only the first
// call to wait will receive this status. However, both cancellation and exceptions flowing through
// tasks set state in the task impl itself.
// When it returns cancelled, either work chore or the cancel thread should already have set task's state
// properly -- cancelled state or completed state (because there was no interruption point).
// For tasks with unwrapped tasks, we should not change the state of current task, since the unwrapped task are still running.
_M_TaskCollection._RunAndWait();
}
catch(details::_Interruption_exception&)
{
// The _TaskCollection will never be an interruption point since it has a none token.
_ASSERTE(false);
}
catch(task_canceled&)
{
// task_canceled is a special exception thrown by cancel_current_task. The spec states that cancel_current_task
// must be called from code that is executed within the task (throwing it from parallel work created by and waited
// upon by the task is acceptable). We can safely assume that the task wrapper _PPLTaskHandle::operator() has seen
// the exception and canceled the task. Swallow the exception here.
_ASSERTE(_IsCanceled());
}
#if defined (__cplusplus_winrt)
catch(::Platform::Exception^ _E)
{
// Its possible the task body hasn't seen the exception, if so we need to cancel with exception here.
if(!_HasUserException())
{
_CancelWithException(_E);
}
// Rethrow will mark the exception as observed.
_M_exceptionHolder->_RethrowUserException();
}
#endif /* defined (__cplusplus_winrt) */
catch(...)
{
// Its possible the task body hasn't seen the exception, if so we need to cancel with exception here.
if(!_HasUserException())
{
_CancelWithException(std::current_exception());
}
// Rethrow will mark the exception as observed.
_M_exceptionHolder->_RethrowUserException();
}
// If the lambda body for this task (executed or waited upon in _RunAndWait above) happened to return a task
// which is to be unwrapped and plumbed to the output of this task, we must not only wait on the lambda body, we must
// wait on the **INNER** body. It is in theory possible that we could inline such if we plumb a series of things through;
// however, this takes the tact of simply waiting upon the completion signal.
if (_M_fUnwrappedTask)
{
_M_TaskCollection._Wait();
}
}
}
if (_HasUserException())
{
_M_exceptionHolder->_RethrowUserException();
}
else if (_IsCanceled())
{
return canceled;
}
_ASSERTE(_IsCompleted());
return completed;
}
/// <summary>
/// Requests cancellation on the task and schedules continuations if the task can be transitioned to a terminal state.
/// </summary>
/// <param name="_SynchronousCancel">
/// Set to true if the cancel takes place as a result of the task body encountering an exception, or because an ancestor or task_completion_event the task
/// was registered with were canceled with an exception. A synchronous cancel is one that assures the task could not be running on a different thread at
/// the time the cancellation is in progress. An asynchronous cancel is one where the thread performing the cancel has no control over the thread that could
/// be executing the task, that is the task could execute concurrently while the cancellation is in progress.
/// </param>
/// <param name="_UserException">
/// Whether an exception other than the internal runtime cancellation exceptions caused this cancellation.
/// </param>
/// <param name="_PropagatedFromAncestor">
/// Whether this exception came from an ancestor task or a task_completion_event as opposed to an exception that was encountered by the task itself. Only valid when
/// _UserException is set to true.
/// </param>
/// <param name="_ExHolder">
/// The exception holder that represents the exception. Only valid when _UserException is set to true.
/// </param>
virtual bool _CancelAndRunContinuations(bool _SynchronousCancel, bool _UserException, bool _PropagatedFromAncestor, const std::shared_ptr<_ExceptionHolder>& _ExHolder) = 0;
bool _Cancel(bool _SynchronousCancel)
{
// Send in a dummy value for exception. It is not used when the first parameter is false.
return _CancelAndRunContinuations(_SynchronousCancel, false, false, _M_exceptionHolder);
}
bool _CancelWithExceptionHolder(const std::shared_ptr<_ExceptionHolder>& _ExHolder, bool _PropagatedFromAncestor)
{
// This task was canceled because an ancestor task encountered an exception.
return _CancelAndRunContinuations(true, true, _PropagatedFromAncestor, _ExHolder);
}
#if defined (__cplusplus_winrt)
bool _CancelWithException(::Platform::Exception^ _Exception)
{
// This task was canceled because the task body encountered an exception.
_ASSERTE(!_HasUserException());
return _CancelAndRunContinuations(true, true, false, std::make_shared<_ExceptionHolder>(_Exception, _GetTaskCreationCallstack()));
}
#endif /* defined (__cplusplus_winrt) */
bool _CancelWithException(const std::exception_ptr& _Exception)
{
// This task was canceled because the task body encountered an exception.
_ASSERTE(!_HasUserException());
return _CancelAndRunContinuations(true, true, false, std::make_shared<_ExceptionHolder>(_Exception, _GetTaskCreationCallstack()));
}
void _RegisterCancellation(std::weak_ptr<_Task_impl_base> _WeakPtr)
{
_ASSERTE(details::_CancellationTokenState::_IsValid(_M_pTokenState));
auto _CancellationCallback = [_WeakPtr](){
// Taking ownership of the task prevents dead lock during destruction
// if the destructor waits for the cancellations to be finished
auto _task = _WeakPtr.lock();
if (_task != nullptr)
_task->_Cancel(false);
};
_M_pRegistration = new details::_CancellationTokenCallback<decltype(_CancellationCallback)>(_CancellationCallback);
_M_pTokenState->_RegisterCallback(_M_pRegistration);
}
void _DeregisterCancellation()
{
if (_M_pRegistration != nullptr)
{
_M_pTokenState->_DeregisterCallback(_M_pRegistration);
_M_pRegistration->_Release();
_M_pRegistration = nullptr;
}
}
bool _IsCreated()
{
return (_M_TaskState == _Created);
}
bool _IsStarted()
{
return (_M_TaskState == _Started);
}
bool _IsPendingCancel()
{
return (_M_TaskState == _PendingCancel);
}
bool _IsCompleted()
{
return (_M_TaskState == _Completed);
}
bool _IsCanceled()
{
return (_M_TaskState == _Canceled);
}
bool _HasUserException()
{
return static_cast<bool>(_M_exceptionHolder);
}
const std::shared_ptr<_ExceptionHolder>& _GetExceptionHolder()
{
_ASSERTE(_HasUserException());
return _M_exceptionHolder;
}
bool _IsApartmentAware()
{
return _M_fFromAsync;
}
void _SetAsync(bool _Async = true)
{
_M_fFromAsync = _Async;
}
_TaskCreationCallstack _GetTaskCreationCallstack()
{
return _M_pTaskCreationCallstack;
}
void _SetTaskCreationCallstack(const _TaskCreationCallstack &_Callstack)
{
_M_pTaskCreationCallstack = _Callstack;
}
/// <summary>
/// Helper function to schedule the task on the Task Collection.
/// </summary>
/// <param name="_PTaskHandle">
/// The task chore handle that need to be executed.
/// </param>
/// <param name="_InliningMode">
/// The inlining scheduling policy for current _PTaskHandle.
/// </param>
void _ScheduleTask(_UnrealizedChore_t * _PTaskHandle, _TaskInliningMode_t _InliningMode)
{
try
{
_M_TaskCollection._ScheduleTask(_PTaskHandle, _InliningMode);
}
catch(const task_canceled &)
{
// task_canceled is a special exception thrown by cancel_current_task. The spec states that cancel_current_task
// must be called from code that is executed within the task (throwing it from parallel work created by and waited
// upon by the task is acceptable). We can safely assume that the task wrapper _PPLTaskHandle::operator() has seen
// the exception and canceled the task. Swallow the exception here.
_ASSERTE(_IsCanceled());
}
catch(const _Interruption_exception &)
{
// The _TaskCollection will never be an interruption point since it has a none token.
_ASSERTE(false);
}
catch(...)
{
// This exception could only have come from within the chore body. It should've been caught
// and the task should be canceled with exception. Swallow the exception here.
_ASSERTE(_HasUserException());
}
}
/// <summary>
/// Function executes a continuation. This function is recorded by a parent task implementation
/// when a continuation is created in order to execute later.
/// </summary>
/// <param name="_PTaskHandle">
/// The continuation task chore handle that need to be executed.
/// </param>
/**/
void _RunContinuation(_ContinuationTaskHandleBase * _PTaskHandle)
{
_Task_ptr_base _ImplBase = _PTaskHandle->_GetTaskImplBase();
if (_IsCanceled() && !_PTaskHandle->_M_isTaskBasedContinuation)
{
if (_HasUserException())
{
// If the ancestor encountered an exception, transfer the exception to the continuation
// This traverses down the tree to propagate the exception.
_ImplBase->_CancelWithExceptionHolder(_GetExceptionHolder(), true);
}
else
{
// If the ancestor was canceled, then your own execution should be canceled.
// This traverses down the tree to cancel it.
_ImplBase->_Cancel(true);
}
}
else
{
// This can only run when the ancestor has completed or it's a task based continuation that fires when a task is canceled
// (with or without a user exception).
_ASSERTE(_IsCompleted() || _PTaskHandle->_M_isTaskBasedContinuation);
_ASSERTE(!_ImplBase->_IsCanceled());
return _ImplBase->_ScheduleContinuationTask(_PTaskHandle);
}
// If the handle is not scheduled, we need to manually delete it.
delete _PTaskHandle;
}
// Schedule a continuation to run
void _ScheduleContinuationTask(_ContinuationTaskHandleBase * _PTaskHandle)
{
_M_taskEventLogger._LogScheduleTask(true);
// Ensure that the continuation runs in proper context (this might be on a Concurrency Runtime thread or in a different Windows Runtime apartment)
if (_PTaskHandle->_M_continuationContext._HasCapturedContext())
{
// For those continuations need to be scheduled inside captured context, we will try to apply automatic inlining to their inline modes,
// if they haven't been specified as _ForceInline yet. This change will encourage those continuations to be executed inline so that reduce
// the cost of marshaling.
// For normal continuations we won't do any change here, and their inline policies are completely decided by ._ThenImpl method.
if (_PTaskHandle->_M_inliningMode != details::_ForceInline)
{
_PTaskHandle->_M_inliningMode = details::_DefaultAutoInline;
}
_ScheduleFuncWithAutoInline([_PTaskHandle]() {
// Note that we cannot directly capture "this" pointer, instead, we should use _TaskImplPtr, a shared_ptr to the _Task_impl_base.
// Because "this" pointer will be invalid as soon as _PTaskHandle get deleted. _PTaskHandle will be deleted after being scheduled.
auto _TaskImplPtr = _PTaskHandle->_GetTaskImplBase();
if (details::_ContextCallback::_CaptureCurrent() == _PTaskHandle->_M_continuationContext)
{
_TaskImplPtr->_ScheduleTask(_PTaskHandle, details::_ForceInline);
}
else
{
//
// It's entirely possible that the attempt to marshal the call into a differing context will fail. In this case, we need to handle
// the exception and mark the continuation as canceled with the appropriate exception. There is one slight hitch to this:
//
// NOTE: COM's legacy behavior is to swallow SEH exceptions and marshal them back as HRESULTS. This will in effect turn an SEH into
// a C++ exception that gets tagged on the task. One unfortunate result of this is that various pieces of the task infrastructure will
// not be in a valid state after this in /EHsc (due to the lack of destructors running, etc...).
//
try
{
// Dev10 compiler needs this!
auto _PTaskHandle1 = _PTaskHandle;
_PTaskHandle->_M_continuationContext._CallInContext( [_PTaskHandle1, _TaskImplPtr](){
_TaskImplPtr->_ScheduleTask(_PTaskHandle1, details::_ForceInline);
});
}
#if defined (__cplusplus_winrt)
catch(::Platform::Exception^ _E)
{
_TaskImplPtr->_CancelWithException(_E);
}
#endif /* defined (__cplusplus_winrt) */
catch(...)
{
_TaskImplPtr->_CancelWithException(std::current_exception());
}
}
}, _PTaskHandle->_M_inliningMode);
}
else
{
_ScheduleTask(_PTaskHandle, _PTaskHandle->_M_inliningMode);
}
}
/// <summary>
/// Schedule the actual continuation. This will either schedule the function on the continuation task's implementation
/// if the task has completed or append it to a list of functions to execute when the task actually does complete.
/// </summary>
/// <typeparam name="_FuncInputType">
/// The input type of the task.
/// </typeparam>
/// <typeparam name="_FuncOutputType">
/// The output type of the task.
/// </typeparam>
/**/
void _ScheduleContinuation(_ContinuationTaskHandleBase * _PTaskHandle)
{
enum { _Nothing, _Schedule, _Cancel, _CancelWithException } _Do = _Nothing;
// If the task has canceled, cancel the continuation. If the task has completed, execute the continuation right away.
// Otherwise, add it to the list of pending continuations
{
::Concurrency::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
if (_IsCompleted() || (_IsCanceled() && _PTaskHandle->_M_isTaskBasedContinuation))
{
_Do = _Schedule;
}
else if (_IsCanceled())
{
if (_HasUserException())
{
_Do = _CancelWithException;
}
else
{
_Do = _Cancel;
}
}
else
{
// chain itself on the continuation chain.
_PTaskHandle->_M_next = _M_Continuations;
_M_Continuations = _PTaskHandle;
}
}
// Cancellation and execution of continuations should be performed after releasing the lock. Continuations off of
// async tasks may execute inline.
switch (_Do)
{
case _Schedule:
{
_PTaskHandle->_GetTaskImplBase()->_ScheduleContinuationTask(_PTaskHandle);
break;
}
case _Cancel:
{
// If the ancestor was canceled, then your own execution should be canceled.
// This traverses down the tree to cancel it.
_PTaskHandle->_GetTaskImplBase()->_Cancel(true);
delete _PTaskHandle;
break;
}
case _CancelWithException:
{
// If the ancestor encountered an exception, transfer the exception to the continuation
// This traverses down the tree to propagate the exception.
_PTaskHandle->_GetTaskImplBase()->_CancelWithExceptionHolder(_GetExceptionHolder(), true);
delete _PTaskHandle;
break;
}
case _Nothing:
default:
// In this case, we have inserted continuation to continuation chain,
// nothing more need to be done, just leave.
break;
}
}
void _RunTaskContinuations()
{
// The link list can no longer be modified at this point,
// since all following up continuations will be scheduled by themselves.
_ContinuationList _Cur = _M_Continuations, _Next;
_M_Continuations = nullptr;
while (_Cur)
{
// Current node might be deleted after running,
// so we must fetch the next first.
_Next = _Cur->_M_next;
_RunContinuation(_Cur);
_Cur = _Next;
}
}
#if defined (__cplusplus_winrt)
static bool _IsNonBlockingThread()
{
APTTYPE _AptType;
APTTYPEQUALIFIER _AptTypeQualifier;
HRESULT hr = CoGetApartmentType(&_AptType, &_AptTypeQualifier);
//
// If it failed, it's not a Windows Runtime/COM initialized thread. This is not a failure.
//
if (SUCCEEDED(hr))
{
switch(_AptType)
{
case APTTYPE_STA:
case APTTYPE_MAINSTA:
return true;
break;
case APTTYPE_NA:
switch(_AptTypeQualifier)
{
// A thread executing in a neutral apartment is either STA or MTA. To find out if this thread is allowed
// to wait, we check the app qualifier. If it is an STA thread executing in a neutral apartment, waiting
// is illegal, because the thread is responsible for pumping messages and waiting on a task could take the
// thread out of circulation for a while.
case APTTYPEQUALIFIER_NA_ON_STA:
case APTTYPEQUALIFIER_NA_ON_MAINSTA:
return true;
break;
}
break;
}
}
#if _UITHREADCTXT_SUPPORT
// This method is used to throw an exepection in _Wait() if called within STA. We
// want the same behavior if _Wait is called on the UI thread.
if (SUCCEEDED(CaptureUiThreadContext(nullptr)))
{
return true;
}
#endif /* _UITHREADCTXT_SUPPORT */
return false;
}
template<typename _ReturnType, typename>
static void _AsyncInit(const typename _Task_ptr<_ReturnType>::_Type & _OuterTask,
Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value>^ _AsyncOp)
{
// This method is invoked either when a task is created from an existing async operation or
// when a lambda that creates an async operation executes.
// If the outer task is pending cancel, cancel the async operation before setting the completed handler. The COM reference on
// the IAsyncInfo object will be released when all ^references to the operation go out of scope.
// This assertion uses the existence of taskcollection to determine if the task was created from an event.
// That is no longer valid as even tasks created from a user lambda could have no underlying taskcollection
// when a custom scheduler is used.
// _ASSERTE((!_OuterTask->_M_TaskCollection._IsCreated() || _OuterTask->_M_fUnwrappedTask) && !_OuterTask->_IsCanceled());
// Pass the shared_ptr by value into the lambda instead of using 'this'.
_AsyncOp->Completed = ref new Windows::Foundation::AsyncOperationCompletedHandler<_ReturnType>(
[_OuterTask](Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value>^ _Operation, Windows::Foundation::AsyncStatus _Status) mutable
{
if (_Status == Windows::Foundation::AsyncStatus::Canceled)
{
_OuterTask->_Cancel(true);
}
else if (_Status == Windows::Foundation::AsyncStatus::Error)
{
_OuterTask->_CancelWithException(::Platform::Exception::ReCreateException(static_cast<int>(_Operation->ErrorCode.Value)));
}
else
{
_ASSERTE(_Status == Windows::Foundation::AsyncStatus::Completed);
_OuterTask->_FinalizeAndRunContinuations(_Operation->GetResults());
}
// Take away this shared pointers reference on the task instead of waiting for the delegate to be released. It could
// be released on a different thread after a delay, and not releasing the reference here could cause the tasks to hold
// on to resources longer than they should. As an example, without this reset, writing to a file followed by reading from
// it using the Windows Runtime Async APIs causes a sharing violation.
// Using const_cast is the workaround for failed mutable keywords
const_cast<_Task_ptr<_ReturnType>::_Type &>(_OuterTask).reset();
});
_OuterTask->_SetUnwrappedAsyncOp(_AsyncOp);
}
#endif /* defined (__cplusplus_winrt) */
template<typename _ReturnType, typename _InternalReturnType>
static void _AsyncInit(const typename _Task_ptr<_ReturnType>::_Type& _OuterTask, const task<_InternalReturnType> & _UnwrappedTask)
{
_ASSERTE(_OuterTask->_M_fUnwrappedTask && !_OuterTask->_IsCanceled());
//
// We must ensure that continuations off _OuterTask (especially exception handling ones) continue to function in the
// presence of an exception flowing out of the inner task _UnwrappedTask. This requires an exception handling continuation
// off the inner task which does the appropriate funnelling to the outer one. We use _Then instead of then to prevent
// the exception from being marked as observed by our internal continuation. This continuation must be scheduled regardless
// of whether or not the _OuterTask task is canceled.
//
_UnwrappedTask._Then([_OuterTask] (task<_InternalReturnType> _AncestorTask) {
if (_AncestorTask._GetImpl()->_IsCompleted())
{
_OuterTask->_FinalizeAndRunContinuations(_AncestorTask._GetImpl()->_GetResult());
}
else
{
_ASSERTE(_AncestorTask._GetImpl()->_IsCanceled());
if (_AncestorTask._GetImpl()->_HasUserException())
{
// Set _PropagatedFromAncestor to false, since _AncestorTask is not an ancestor of _UnwrappedTask.
// Instead, it is the enclosing task.
_OuterTask->_CancelWithExceptionHolder(_AncestorTask._GetImpl()->_GetExceptionHolder(), false);
}
else
{
_OuterTask->_Cancel(true);
}
}
}, nullptr, details::_DefaultAutoInline);
}
scheduler_ptr _GetScheduler() const
{
return _M_TaskCollection._GetScheduler();
}
// Tracks the internal state of the task
volatile _TaskInternalState _M_TaskState;
// Set to true either if the ancestor task had the flag set to true, or if the lambda that does the work of this task returns an
// async operation or async action that is unwrapped by the runtime.
bool _M_fFromAsync;
// Set to true when a continuation unwraps a task or async operation.
bool _M_fUnwrappedTask;
// An exception thrown by the task body is captured in an exception holder and it is shared with all value based continuations rooted at the task.
// The exception is 'observed' if the user invokes get()/wait() on any of the tasks that are sharing this exception holder. If the exception
// is not observed by the time the internal object owned by the shared pointer destructs, the process will fail fast.
std::shared_ptr<_ExceptionHolder> _M_exceptionHolder;
typedef _ContinuationTaskHandleBase * _ContinuationList;
::Concurrency::extensibility::critical_section_t _M_ContinuationsCritSec;
_ContinuationList _M_Continuations;
// The cancellation token state.
_CancellationTokenState * _M_pTokenState;
// The registration on the token.
_CancellationTokenRegistration * _M_pRegistration;
// The async task collection wrapper
::Concurrency::details::_TaskCollection_t _M_TaskCollection;
// Callstack for function call (constructor or .then) that created this task impl.
_TaskCreationCallstack _M_pTaskCreationCallstack;
_TaskEventLogger _M_taskEventLogger;
private:
// Must not be copied by value:
_Task_impl_base(const _Task_impl_base&);
_Task_impl_base const & operator=(_Task_impl_base const&);
};
#if _PPLTASK_ASYNC_LOGGING
inline void _TaskEventLogger::_LogTaskCompleted()
{
if (_M_scheduled)
{
::Windows::Foundation::AsyncStatus _State;
if (_M_task->_IsCompleted())
_State = ::Windows::Foundation::AsyncStatus::Completed;
else if (_M_task->_HasUserException())
_State = ::Windows::Foundation::AsyncStatus::Error;
else
_State = ::Windows::Foundation::AsyncStatus::Canceled;
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceOperationCompletion(::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required, ::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID, reinterpret_cast<unsigned long long>(_M_task), _State);
}
}
}
#endif
/// <summary>
/// The implementation of a first-class task. This structure contains the task group used to execute
/// the task function and handles the scheduling. The _Task_impl is created as a shared_ptr
/// member of the the public task class, so its destruction is handled automatically.
/// </summary>
/// <typeparam name="_ReturnType">
/// The result type of this task.
/// </typeparam>
/**/
template<typename _ReturnType>
struct _Task_impl : public _Task_impl_base
{
#if defined (__cplusplus_winrt)
typedef Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value> _AsyncOperationType;
#endif // defined(__cplusplus_winrt)
_Task_impl(_CancellationTokenState * _Ct, scheduler_ptr _Scheduler_arg)
: _Task_impl_base(_Ct, _Scheduler_arg)
{
#if defined (__cplusplus_winrt)
_M_unwrapped_async_op = nullptr;
#endif /* defined (__cplusplus_winrt) */
}
virtual ~_Task_impl()
{
// We must invoke _DeregisterCancellation in the derived class destructor. Calling it in the base class destructor could cause
// a partially initialized _Task_impl to be in the list of registrations for a cancellation token.
_DeregisterCancellation();
}
virtual bool _CancelAndRunContinuations(bool _SynchronousCancel, bool _UserException, bool _PropagatedFromAncestor, const std::shared_ptr<_ExceptionHolder> & _ExceptionHolder_arg)
{
enum { _Nothing, _RunContinuations, _Cancel } _Do = _Nothing;
{
::Concurrency::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
if (_UserException)
{
_ASSERTE(_SynchronousCancel && !_IsCompleted());
// If the state is _Canceled, the exception has to be coming from an ancestor.
_ASSERTE(!_IsCanceled() || _PropagatedFromAncestor);
// We should not be canceled with an exception more than once.
_ASSERTE(!_HasUserException());
if (_M_TaskState == _Canceled)
{
// If the task has finished cancelling there should not be any continuation records in the array.
return false;
}
else
{
_ASSERTE(_M_TaskState != _Completed);
_M_exceptionHolder = _ExceptionHolder_arg;
}
}
else
{
// Completed is a non-cancellable state, and if this is an asynchronous cancel, we're unable to do better than the last async cancel
// which is to say, cancellation is already initiated, so return early.
if (_IsCompleted() || _IsCanceled() || (_IsPendingCancel() && !_SynchronousCancel))
{
_ASSERTE(!_IsCompleted() || !_HasUserException());
return false;
}
_ASSERTE(!_SynchronousCancel || !_HasUserException());
}
if (_SynchronousCancel)
{
// Be aware that this set must be done BEFORE _M_Scheduled being set, or race will happen between this and wait()
_M_TaskState = _Canceled;
// Cancellation completes the task, so all dependent tasks must be run to cancel them
// They are canceled when they begin running (see _RunContinuation) and see that their
// ancestor has been canceled.
_Do = _RunContinuations;
}
else
{
_ASSERTE(!_UserException);
if (_IsStarted())
{
// should not initiate cancellation under a lock
_Do = _Cancel;
}
// The _M_TaskState variable transitions to _Canceled when cancellation is completed (the task is not executing user code anymore).
// In the case of a synchronous cancel, this can happen immediately, whereas with an asynchronous cancel, the task has to move from
// _Started to _PendingCancel before it can move to _Canceled when it is finished executing.
_M_TaskState = _PendingCancel;
_M_taskEventLogger._LogCancelTask();
}
}
switch (_Do)
{
case _Cancel:
{
#if defined (__cplusplus_winrt)
if (_M_unwrapped_async_op != nullptr)
{
// We will only try to cancel async operation but not unwrapped tasks, since unwrapped tasks cannot be canceled without its token.
_M_unwrapped_async_op->Cancel();
}
#endif /* defined (__cplusplus_winrt) */
_M_TaskCollection._Cancel();
break;
}
case _RunContinuations:
{
// Only execute continuations and mark the task as completed if we were able to move the task to the _Canceled state.
_M_TaskCollection._Complete();
if (_M_Continuations)
{
// Scheduling cancellation with automatic inlining.
_ScheduleFuncWithAutoInline([=](){ _RunTaskContinuations(); }, details::_DefaultAutoInline);
}
break;
}
}
return true;
}
void _FinalizeAndRunContinuations(_ReturnType _Result)
{
_M_Result.Set(_Result);
{
//
// Hold this lock to ensure continuations being concurrently either get added
// to the _M_Continuations vector or wait for the result
//
::Concurrency::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
// A task could still be in the _Created state if it was created with a task_completion_event.
// It could also be in the _Canceled state for the same reason.
_ASSERTE(!_HasUserException() && !_IsCompleted());
if (_IsCanceled())
{
return;
}
// Always transition to "completed" state, even in the face of unacknowledged pending cancellation
_M_TaskState = _Completed;
}
_M_TaskCollection._Complete();
_RunTaskContinuations();
}
//
// This method is invoked when the starts executing. The task returns early if this method returns true.
//
bool _TransitionedToStarted()
{
::Concurrency::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
// Canceled state could only result from antecedent task's canceled state, but that code path will not reach here.
_ASSERT(!_IsCanceled());
if (_IsPendingCancel())
return false;
_ASSERTE(_IsCreated());
_M_TaskState = _Started;
return true;
}
#if defined (__cplusplus_winrt)
void _SetUnwrappedAsyncOp(_AsyncOperationType^ _AsyncOp)
{
::Concurrency::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
// Cancel the async operation if the task itself is canceled, since the thread that canceled the task missed it.
if (_IsPendingCancel())
{
_ASSERTE(!_IsCanceled());
_AsyncOp->Cancel();
}
else
{
_M_unwrapped_async_op = _AsyncOp;
}
}
#endif /* defined (__cplusplus_winrt) */
// Return true if the task has reached a terminal state
bool _IsDone()
{
return _IsCompleted() || _IsCanceled();
}
_ReturnType _GetResult()
{
return _M_Result.Get();
}
_ResultHolder<_ReturnType> _M_Result; // this means that the result type must have a public default ctor.
#if defined (__cplusplus_winrt)
_AsyncOperationType^ _M_unwrapped_async_op;
#endif /* defined (__cplusplus_winrt) */
};
template<typename _ResultType>
struct _Task_completion_event_impl
{
private:
_Task_completion_event_impl(const _Task_completion_event_impl&);
_Task_completion_event_impl& operator=(const _Task_completion_event_impl&);
public:
typedef std::vector<typename _Task_ptr<_ResultType>::_Type> _TaskList;
_Task_completion_event_impl() :
_M_fHasValue(false), _M_fIsCanceled(false)
{
}
bool _HasUserException()
{
return _M_exceptionHolder != nullptr;
}
~_Task_completion_event_impl()
{
for( auto _TaskIt = _M_tasks.begin(); _TaskIt != _M_tasks.end(); ++_TaskIt )
{
_ASSERTE(!_M_fHasValue && !_M_fIsCanceled);
// Cancel the tasks since the event was never signaled or canceled.
(*_TaskIt)->_Cancel(true);
}
}
// We need to protect the loop over the array, so concurrent_vector would not have helped
_TaskList _M_tasks;
::Concurrency::extensibility::critical_section_t _M_taskListCritSec;
_ResultHolder<_ResultType> _M_value;
std::shared_ptr<_ExceptionHolder> _M_exceptionHolder;
bool _M_fHasValue;
bool _M_fIsCanceled;
};
// Utility method for dealing with void functions
inline std::function<_Unit_type(void)> _MakeVoidToUnitFunc(const std::function<void(void)>& _Func)
{
return [=]() -> _Unit_type { _Func(); return _Unit_type(); };
}
template <typename _Type>
std::function<_Type(_Unit_type)> _MakeUnitToTFunc(const std::function<_Type(void)>& _Func)
{
return [=](_Unit_type) -> _Type { return _Func(); };
}
template <typename _Type>
std::function<_Unit_type(_Type)> _MakeTToUnitFunc(const std::function<void(_Type)>& _Func)
{
return [=](_Type t) -> _Unit_type { _Func(t); return _Unit_type(); };
}
inline std::function<_Unit_type(_Unit_type)> _MakeUnitToUnitFunc(const std::function<void(void)>& _Func)
{
return [=](_Unit_type) -> _Unit_type { _Func(); return _Unit_type(); };
}
} // namespace details
/// <summary>
/// The <c>task_completion_event</c> class allows you to delay the execution of a task until a condition is satisfied,
/// or start a task in response to an external event.
/// </summary>
/// <typeparam name="_ResultType">
/// The result type of this <c>task_completion_event</c> class.
/// </typeparam>
/// <remarks>
/// Use a task created from a task completion event when your scenario requires you to create a task that will complete, and
/// thereby have its continuations scheduled for execution, at some point in the future. The <c>task_completion_event</c> must
/// have the same type as the task you create, and calling the set method on the task completion event with a value of that type
/// will cause the associated task to complete, and provide that value as a result to its continuations.
/// <para>If the task completion event is never signaled, any tasks created from it will be canceled when it is destructed.</para>
/// <para><c>task_completion_event</c> behaves like a smart pointer, and should be passed by value.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/**/
template<typename _ResultType>
class task_completion_event
{
public:
/// <summary>
/// Constructs a <c>task_completion_event</c> object.
/// </summary>
/**/
task_completion_event()
: _M_Impl(std::make_shared<details::_Task_completion_event_impl<_ResultType>>())
{
}
/// <summary>
/// Sets the task completion event.
/// </summary>
/// <param name="_Result">
/// The result to set this event with.
/// </param>
/// <returns>
/// The method returns <c>true</c> if it was successful in setting the event. It returns <c>false</c> if the event is already set.
/// </returns>
/// <remarks>
/// In the presence of multiple or concurrent calls to <c>set</c>, only the first call will succeed and its result (if any) will be stored in the
/// task completion event. The remaining sets are ignored and the method will return false. When you set a task completion event, all the
/// tasks created from that event will immediately complete, and its continuations, if any, will be scheduled. Task completion objects that have
/// a <typeparamref name="_ResultType"/> other than <c>void</c> will pass the value <paramref value="_Result"/> to their continuations.
/// </remarks>
/**/
bool set(_ResultType _Result) const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
// Subsequent sets are ignored. This makes races to set benign: the first setter wins and all others are ignored.
if (_IsTriggered())
{
return false;
}
_TaskList _Tasks;
bool _RunContinuations = false;
{
::Concurrency::extensibility::scoped_critical_section_t _LockHolder(_M_Impl->_M_taskListCritSec);
if (!_IsTriggered())
{
_M_Impl->_M_value.Set(_Result);
_M_Impl->_M_fHasValue = true;
_Tasks.swap(_M_Impl->_M_tasks);
_RunContinuations = true;
}
}
if (_RunContinuations)
{
for( auto _TaskIt = _Tasks.begin(); _TaskIt != _Tasks.end(); ++_TaskIt )
{
// If current task was cancelled by a cancellation_token, it would be in cancel pending state.
if ((*_TaskIt)->_IsPendingCancel())
(*_TaskIt)->_Cancel(true);
else
{
// Tasks created with task_completion_events can be marked as async, (we do this in when_any and when_all
// if one of the tasks involved is an async task). Since continuations of async tasks can execute inline, we
// need to run continuations after the lock is released.
(*_TaskIt)->_FinalizeAndRunContinuations(_M_Impl->_M_value.Get());
}
}
if (_M_Impl->_HasUserException())
{
_M_Impl->_M_exceptionHolder.reset();
}
return true;
}
return false;
}
template<typename _E>
__declspec(noinline) // Ask for no inlining so that the _ReturnAddress intrinsic gives us the expected result
bool set_exception(_E _Except) const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
// It is important that _CAPTURE_CALLSTACK() evaluate to the instruction after the call instruction for set_exception.
return _Cancel(std::make_exception_ptr(_Except), _CAPTURE_CALLSTACK());
}
/// <summary>
/// Propagates an exception to all tasks associated with this event.
/// </summary>
/// <param>
/// The exception_ptr that indicates the exception to set this event with.
/// </param>
/**/
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK gives us the expected result
bool set_exception(std::exception_ptr _ExceptionPtr) const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
// It is important that _CAPTURE_CALLSTACK() evaluate to the instruction after the call instruction for set_exception.
return _Cancel(_ExceptionPtr, _CAPTURE_CALLSTACK());
}
/// <summary>
/// Internal method to cancel the task_completion_event. Any task created using this event will be marked as canceled if it has
/// not already been set.
/// </summary>
bool _Cancel() const
{
// Cancel with the stored exception if one exists.
return _CancelInternal();
}
/// <summary>
/// Internal method to cancel the task_completion_event with the exception provided. Any task created using this event will be canceled
/// with the same exception.
/// </summary>
template<typename _ExHolderType>
bool _Cancel(_ExHolderType _ExHolder, const details::_TaskCreationCallstack &_SetExceptionAddressHint = details::_TaskCreationCallstack ()) const
{
bool _Canceled;
if(_StoreException(_ExHolder, _SetExceptionAddressHint))
{
_Canceled = _CancelInternal();
_ASSERTE(_Canceled);
}
else
{
_Canceled = false;
}
return _Canceled;
}
/// <summary>
/// Internal method that stores an exception in the task completion event. This is used internally by when_any.
/// Note, this does not cancel the task completion event. A task completion event with a stored exception
/// can bet set() successfully. If it is canceled, it will cancel with the stored exception, if one is present.
/// </summary>
template<typename _ExHolderType>
bool _StoreException(_ExHolderType _ExHolder, const details::_TaskCreationCallstack &_SetExceptionAddressHint = details::_TaskCreationCallstack ()) const
{
::Concurrency::extensibility::scoped_critical_section_t _LockHolder(_M_Impl->_M_taskListCritSec);
if (!_IsTriggered() && !_M_Impl->_HasUserException())
{
// Create the exception holder only if we have ensured there we will be successful in setting it onto the
// task completion event. Failing to do so will result in an unobserved task exception.
_M_Impl->_M_exceptionHolder = _ToExceptionHolder(_ExHolder, _SetExceptionAddressHint);
return true;
}
return false;
}
/// <summary>
/// Tests whether current event has been either Set, or Canceled.
/// </summary>
bool _IsTriggered() const
{
return _M_Impl->_M_fHasValue || _M_Impl->_M_fIsCanceled;
}
private:
static std::shared_ptr<details::_ExceptionHolder> _ToExceptionHolder(const std::shared_ptr<details::_ExceptionHolder>& _ExHolder, const details::_TaskCreationCallstack&)
{
return _ExHolder;
}
static std::shared_ptr<details::_ExceptionHolder> _ToExceptionHolder(std::exception_ptr _ExceptionPtr, const details::_TaskCreationCallstack &_SetExceptionAddressHint)
{
return std::make_shared<details::_ExceptionHolder>(_ExceptionPtr, _SetExceptionAddressHint);
}
template <typename T> friend class task; // task can register itself with the event by calling the private _RegisterTask
template <typename T> friend class task_completion_event;
typedef typename details::_Task_completion_event_impl<_ResultType>::_TaskList _TaskList;
/// <summary>
/// Cancels the task_completion_event.
/// </summary>
bool _CancelInternal() const
{
// Cancellation of task completion events is an internal only utility. Our usage is such that _CancelInternal
// will never be invoked if the task completion event has been set.
_ASSERTE(!_M_Impl->_M_fHasValue);
if (_M_Impl->_M_fIsCanceled)
{
return false;
}
_TaskList _Tasks;
bool _Cancel = false;
{
::Concurrency::extensibility::scoped_critical_section_t _LockHolder(_M_Impl->_M_taskListCritSec);
_ASSERTE(!_M_Impl->_M_fHasValue);
if (!_M_Impl->_M_fIsCanceled)
{
_M_Impl->_M_fIsCanceled = true;
_Tasks.swap(_M_Impl->_M_tasks);
_Cancel = true;
}
}
bool _UserException = _M_Impl->_HasUserException();
if (_Cancel)
{
for( auto _TaskIt = _Tasks.begin(); _TaskIt != _Tasks.end(); ++_TaskIt )
{
// Need to call this after the lock is released. See comments in set().
if (_UserException)
{
(*_TaskIt)->_CancelWithExceptionHolder(_M_Impl->_M_exceptionHolder, true);
}
else
{
(*_TaskIt)->_Cancel(true);
}
}
}
return _Cancel;
}
/// <summary>
/// Register a task with this event. This function is called when a task is constructed using
/// a task_completion_event.
/// </summary>
void _RegisterTask(const typename details::_Task_ptr<_ResultType>::_Type & _TaskParam)
{
::Concurrency::extensibility::scoped_critical_section_t _LockHolder(_M_Impl->_M_taskListCritSec);
//If an exception was already set on this event, then cancel the task with the stored exception.
if(_M_Impl->_HasUserException())
{
_TaskParam->_CancelWithExceptionHolder(_M_Impl->_M_exceptionHolder, true);
}
else if (_M_Impl->_M_fHasValue)
{
_TaskParam->_FinalizeAndRunContinuations(_M_Impl->_M_value.Get());
}
else
{
_M_Impl->_M_tasks.push_back(_TaskParam);
}
}
std::shared_ptr<details::_Task_completion_event_impl<_ResultType>> _M_Impl;
};
/// <summary>
/// The <c>task_completion_event</c> class allows you to delay the execution of a task until a condition is satisfied,
/// or start a task in response to an external event.
/// </summary>
/// <remarks>
/// Use a task created from a task completion event when your scenario requires you to create a task that will complete, and
/// thereby have its continuations scheduled for execution, at some point in the future. The <c>task_completion_event</c> must
/// have the same type as the task you create, and calling the set method on the task completion event with a value of that type
/// will cause the associated task to complete, and provide that value as a result to its continuations.
/// <para>If the task completion event is never signaled, any tasks created from it will be canceled when it is destructed.</para>
/// <para><c>task_completion_event</c> behaves like a smart pointer, and should be passed by value.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/**/
template<>
class task_completion_event<void>
{
public:
/// <summary>
/// Sets the task completion event.
/// </summary>
/// <returns>
/// The method returns <c>true</c> if it was successful in setting the event. It returns <c>false</c> if the event is already set.
/// </returns>
/// <remarks>
/// In the presence of multiple or concurrent calls to <c>set</c>, only the first call will succeed and its result (if any) will be stored in the
/// task completion event. The remaining sets are ignored and the method will return false. When you set a task completion event, all the
/// tasks created from that event will immediately complete, and its continuations, if any, will be scheduled. Task completion objects that have
/// a <typeparamref name="_ResultType"/> other than <c>void</c> will pass the value <paramref value="_Result"/> to their continuations.
/// </remarks>
/**/
bool set() const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
return _M_unitEvent.set(details::_Unit_type());
}
template<typename _E>
__declspec(noinline) // Ask for no inlining so that the _ReturnAddress intrinsic gives us the expected result
bool set_exception(_E _Except) const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
return _M_unitEvent._Cancel(std::make_exception_ptr(_Except), _CAPTURE_CALLSTACK());
}
/// <summary>
/// Propagates an exception to all tasks associated with this event.
/// </summary>
/// <param>
/// The exception_ptr that indicates the exception to set this event with.
/// </param>
/**/
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK intrinsic gives us the expected result
bool set_exception(std::exception_ptr _ExceptionPtr) const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
// It is important that _CAPTURE_CALLSTACK() evaluate to the instruction after the call instruction for set_exception.
return _M_unitEvent._Cancel(_ExceptionPtr, _CAPTURE_CALLSTACK());
}
/// <summary>
/// Cancel the task_completion_event. Any task created using this event will be marked as canceled if it has
/// not already been set.
/// </summary>
void _Cancel() const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
_M_unitEvent._Cancel();
}
/// <summary>
/// Cancel the task_completion_event with the exception holder provided. Any task created using this event will be canceled
/// with the same exception.
/// </summary>
void _Cancel(const std::shared_ptr<details::_ExceptionHolder>& _ExHolder) const
{
_M_unitEvent._Cancel(_ExHolder);
}
/// <summary>
/// Method that stores an exception in the task completion event. This is used internally by when_any.
/// Note, this does not cancel the task completion event. A task completion event with a stored exception
/// can bet set() successfully. If it is canceled, it will cancel with the stored exception, if one is present.
/// </summary>
bool _StoreException(const std::shared_ptr<details::_ExceptionHolder>& _ExHolder) const
{
return _M_unitEvent._StoreException(_ExHolder);
}
/// <summary>
/// Test whether current event has been either Set, or Canceled.
/// </summary>
bool _IsTriggered() const
{
return _M_unitEvent._IsTriggered();
}
private:
template <typename T> friend class task; // task can register itself with the event by calling the private _RegisterTask
/// <summary>
/// Register a task with this event. This function is called when a task is constructed using
/// a task_completion_event.
/// </summary>
void _RegisterTask(details::_Task_ptr<details::_Unit_type>::_Type _TaskParam)
{
_M_unitEvent._RegisterTask(_TaskParam);
}
// The void event contains an event a dummy type so common code can be used for events with void and non-void results.
task_completion_event<details::_Unit_type> _M_unitEvent;
};
namespace details
{
//
// Compile-time validation helpers
//
// Task constructor validation: issue helpful diagnostics for common user errors. Do not attempt full validation here.
//
// Anything callable is fine
template<typename _ReturnType, typename _Ty>
auto _IsValidTaskCtor(_Ty _Param, int,int,int,int) -> decltype(_Param(), std::true_type());
#if defined (__cplusplus_winrt)
// Anything that has GetResults is fine: this covers all async operations
template<typename _ReturnType, typename _Ty>
auto _IsValidTaskCtor(_Ty _Param, int, int, int,...) -> decltype(_Param->GetResults(), std::true_type());
#endif
// Allow parameters with set: this covers task_completion_event
template<typename _ReturnType, typename _Ty>
auto _IsValidTaskCtor(_Ty _Param, int, int, ...) -> decltype(_Param.set(stdx::declval<_ReturnType>()), std::true_type());
template<typename _ReturnType, typename _Ty>
auto _IsValidTaskCtor(_Ty _Param, int, ...) -> decltype(_Param.set(), std::true_type());
// All else is invalid
template<typename _ReturnType, typename _Ty>
std::false_type _IsValidTaskCtor(_Ty _Param, ...);
template<typename _ReturnType, typename _Ty>
void _ValidateTaskConstructorArgs(_Ty _Param)
{
static_assert(std::is_same<decltype(_IsValidTaskCtor<_ReturnType>(_Param,0,0,0,0)),std::true_type>::value,
#if defined (__cplusplus_winrt)
"incorrect argument for task constructor; can be a callable object, an asynchronous operation, or a task_completion_event"
#else /* defined (__cplusplus_winrt) */
"incorrect argument for task constructor; can be a callable object or a task_completion_event"
#endif /* defined (__cplusplus_winrt) */
);
#if defined (__cplusplus_winrt)
static_assert(!(std::is_same<_Ty,_ReturnType>::value && details::_IsIAsyncInfo<_Ty>::_Value),
"incorrect template argument for task; consider using the return type of the async operation");
#endif /* defined (__cplusplus_winrt) */
}
#if defined (__cplusplus_winrt)
// Helpers for create_async validation
//
// A parameter lambda taking no arguments is valid
template<typename _Ty>
static auto _IsValidCreateAsync(_Ty _Param, int, int, int, int) -> decltype(_Param(), std::true_type());
// A parameter lambda taking an cancellation_token argument is valid
template<typename _Ty>
static auto _IsValidCreateAsync(_Ty _Param, int, int, int, ...) -> decltype(_Param(cancellation_token::none()), std::true_type());
// A parameter lambda taking a progress report argument is valid
template<typename _Ty>
static auto _IsValidCreateAsync(_Ty _Param, int, int, ...) -> decltype(_Param(details::_ProgressReporterCtorArgType()), std::true_type());
// A parameter lambda taking a progress report and a cancellation_token argument is valid
template<typename _Ty>
static auto _IsValidCreateAsync(_Ty _Param, int, ...) -> decltype(_Param(details::_ProgressReporterCtorArgType(), cancellation_token::none()), std::true_type());
// All else is invalid
template<typename _Ty>
static std::false_type _IsValidCreateAsync(_Ty _Param, ...);
#endif /* defined (__cplusplus_winrt) */
}
/// <summary>
/// A helper class template that transforms a continuation lambda that either takes or returns void, or both, into a lambda that takes and returns a
/// non-void type (details::_Unit_type is used to substitute for void). This is to minimize the special handling required for 'void'.
/// </summary>
template<typename _InpType, typename _OutType>
class _Continuation_func_transformer
{
public:
static auto _Perform(std::function<_OutType(_InpType)> _Func) -> decltype(_Func)
{
return _Func;
}
};
template<typename _OutType>
class _Continuation_func_transformer<void, _OutType>
{
public:
static auto _Perform(std::function<_OutType(void)> _Func) -> decltype(details::_MakeUnitToTFunc<_OutType>(_Func))
{
return details::_MakeUnitToTFunc<_OutType>(_Func);
}
};
template<typename _InType>
class _Continuation_func_transformer<_InType, void>
{
public:
static auto _Perform(std::function<void(_InType)> _Func) -> decltype(details::_MakeTToUnitFunc<_InType>(_Func))
{
return details::_MakeTToUnitFunc<_InType>(_Func);
}
};
template<>
class _Continuation_func_transformer<void, void>
{
public:
static auto _Perform(std::function<void(void)> _Func) -> decltype(details::_MakeUnitToUnitFunc(_Func))
{
return details::_MakeUnitToUnitFunc(_Func);
}
};
// A helper class template that transforms an intial task lambda returns void into a lambda that returns a non-void type (details::_Unit_type is used
// to substitute for void). This is to minimize the special handling required for 'void'.
template<typename _RetType>
class _Init_func_transformer
{
public:
static auto _Perform(std::function<_RetType(void)> _Func) -> decltype(_Func)
{
return _Func;
}
};
template<>
class _Init_func_transformer<void>
{
public:
static auto _Perform(std::function<void(void)> _Func) -> decltype(details::_MakeVoidToUnitFunc(_Func))
{
return details::_MakeVoidToUnitFunc(_Func);
}
};
/// <summary>
/// The Parallel Patterns Library (PPL) <c>task</c> class. A <c>task</c> object represents work that can be executed asynchronously,
/// and concurrently with other tasks and parallel work produced by parallel algorithms in the Concurrency Runtime. It produces
/// a result of type <typeparamref name="_ResultType"/> on successful completion. Tasks of type <c>task&lt;void&gt;</c> produce no result.
/// A task can be waited upon and canceled independently of other tasks. It can also be composed with other tasks using
/// continuations(<c>then</c>), and join(<c>when_all</c>) and choice(<c>when_any</c>) patterns.
/// </summary>
/// <typeparam name="_ReturnType">
/// The result type of this task.
/// </typeparam>
/// <remarks>
/// For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.
/// </remarks>
/**/
template<typename _ReturnType>
class task
{
public:
/// <summary>
/// The type of the result an object of this class produces.
/// </summary>
/**/
typedef _ReturnType result_type;
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within containers.
/// A default constructed task cannot be used until you assign a valid task to it. Methods such as <c>get</c>, <c>wait</c> or <c>then</c>
/// will throw an <see cref="invalid_argument Class">invalid_argument</see> exception when called on a default constructed task.
/// <para>A task that is created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the task
/// completion event is set.</para>
/// <para>The version of the constructor that takes a cancellation token creates a task that can be canceled using the
/// <c>cancellation_token_source</c> the token was obtained from. Tasks created without a cancellation token are not cancelable.</para>
/// <para>Tasks created from a <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes. Similarly, tasks created
/// from a lamda that returns a <c>task&lt;result_type&gt;</c> reach their terminal state when the inner task reaches its terminal state,
/// and not when the lamda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by multiple threads
/// without the need for locks.</para>
/// <para>The constructor overloads that take a Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available
/// to Windows Store apps.</para>
/// <para>For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
task() : _M_Impl(nullptr)
{
// The default constructor should create a task with a nullptr impl. This is a signal that the
// task is not usable and should throw if any wait(), get() or then() APIs are used.
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda, a function object, a <c>task_completion_event&lt;result_type&gt;</c>
/// object, or a Windows::Foundation::IAsyncInfo if you are using tasks in your Windows Store app. The lambda or function
/// object should be a type equivalent to <c>std::function&lt;X(void)&gt;</c>, where X can be a variable of type <c>result_type</c>,
/// <c>task&lt;result_type&gt;</c>, or a Windows::Foundation::IAsyncInfo in Windows Store apps.
/// </param>
/// <param name="_Token">
/// The cancellation token to associate with this task. A task created without a cancellation token cannot be canceled. It implicitly receives
/// the token <c>cancellation_token::none()</c>.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within containers.
/// A default constructed task cannot be used until you assign a valid task to it. Methods such as <c>get</c>, <c>wait</c> or <c>then</c>
/// will throw an <see cref="invalid_argument Class">invalid_argument</see> exception when called on a default constructed task.
/// <para>A task that is created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the task
/// completion event is set.</para>
/// <para>The version of the constructor that takes a cancellation token creates a task that can be canceled using the
/// <c>cancellation_token_source</c> the token was obtained from. Tasks created without a cancellation token are not cancelable.</para>
/// <para>Tasks created from a <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes. Similarly, tasks created
/// from a lamda that returns a <c>task&lt;result_type&gt;</c> reach their terminal state when the inner task reaches its terminal state,
/// and not when the lamda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by multiple threads
/// without the need for locks.</para>
/// <para>The constructor overloads that take a Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available
/// to Windows Store apps.</para>
/// <para>For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Ty>
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK gives us the expected result
explicit task(_Ty _Param)
{
task_options _TaskOptions;
details::_ValidateTaskConstructorArgs<_ReturnType,_Ty>(_Param);
_CreateImpl(_TaskOptions.get_cancellation_token()._GetImplValue(), _TaskOptions.get_scheduler());
// Do not move the next line out of this function. It is important that _CAPTURE_CALLSTACK() evaluate to the the call site of the task constructor.
_SetTaskCreationCallstack(_CAPTURE_CALLSTACK());
_TaskInitMaybeFunctor(_Param, details::_IsCallable(_Param,0));
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda, a function object, a <c>task_completion_event&lt;result_type&gt;</c>
/// object, or a Windows::Foundation::IAsyncInfo if you are using tasks in your Windows Store app. The lambda or function
/// object should be a type equivalent to <c>std::function&lt;X(void)&gt;</c>, where X can be a variable of type <c>result_type</c>,
/// <c>task&lt;result_type&gt;</c>, or a Windows::Foundation::IAsyncInfo in Windows Store apps.
/// </param>
/// <param name="_TaskOptions">
/// The task options include cancellation token, scheduler etc
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within containers.
/// A default constructed task cannot be used until you assign a valid task to it. Methods such as <c>get</c>, <c>wait</c> or <c>then</c>
/// will throw an <see cref="invalid_argument Class">invalid_argument</see> exception when called on a default constructed task.
/// <para>A task that is created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the task
/// completion event is set.</para>
/// <para>The version of the constructor that takes a cancellation token creates a task that can be canceled using the
/// <c>cancellation_token_source</c> the token was obtained from. Tasks created without a cancellation token are not cancelable.</para>
/// <para>Tasks created from a <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes. Similarly, tasks created
/// from a lamda that returns a <c>task&lt;result_type&gt;</c> reach their terminal state when the inner task reaches its terminal state,
/// and not when the lamda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by multiple threads
/// without the need for locks.</para>
/// <para>The constructor overloads that take a Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available
/// to Windows Store apps.</para>
/// <para>For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Ty>
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK gives us the expected result
explicit task(_Ty _Param, const task_options &_TaskOptions)
{
details::_ValidateTaskConstructorArgs<_ReturnType,_Ty>(_Param);
_CreateImpl(_TaskOptions.get_cancellation_token()._GetImplValue(), _TaskOptions.get_scheduler());
// Do not move the next line out of this function. It is important that _CAPTURE_CALLSTACK() evaluate to the the call site of the task constructor.
_SetTaskCreationCallstack(details::_get_internal_task_options(_TaskOptions)._M_hasPresetCreationCallstack ? details::_get_internal_task_options(_TaskOptions)._M_presetCreationCallstack : _CAPTURE_CALLSTACK());
_TaskInitMaybeFunctor(_Param, details::_IsCallable(_Param,0));
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within containers.
/// A default constructed task cannot be used until you assign a valid task to it. Methods such as <c>get</c>, <c>wait</c> or <c>then</c>
/// will throw an <see cref="invalid_argument Class">invalid_argument</see> exception when called on a default constructed task.
/// <para>A task that is created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the task
/// completion event is set.</para>
/// <para>The version of the constructor that takes a cancellation token creates a task that can be canceled using the
/// <c>cancellation_token_source</c> the token was obtained from. Tasks created without a cancellation token are not cancelable.</para>
/// <para>Tasks created from a <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes. Similarly, tasks created
/// from a lamda that returns a <c>task&lt;result_type&gt;</c> reach their terminal state when the inner task reaches its terminal state,
/// and not when the lamda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by multiple threads
/// without the need for locks.</para>
/// <para>The constructor overloads that take a Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available
/// to Windows Store apps.</para>
/// <para>For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
task(const task& _Other): _M_Impl(_Other._M_Impl) {}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within containers.
/// A default constructed task cannot be used until you assign a valid task to it. Methods such as <c>get</c>, <c>wait</c> or <c>then</c>
/// will throw an <see cref="invalid_argument Class">invalid_argument</see> exception when called on a default constructed task.
/// <para>A task that is created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the task
/// completion event is set.</para>
/// <para>The version of the constructor that takes a cancellation token creates a task that can be canceled using the
/// <c>cancellation_token_source</c> the token was obtained from. Tasks created without a cancellation token are not cancelable.</para>
/// <para>Tasks created from a <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes. Similarly, tasks created
/// from a lamda that returns a <c>task&lt;result_type&gt;</c> reach their terminal state when the inner task reaches its terminal state,
/// and not when the lamda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by multiple threads
/// without the need for locks.</para>
/// <para>The constructor overloads that take a Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available
/// to Windows Store apps.</para>
/// <para>For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
task(task&& _Other): _M_Impl(std::move(_Other._M_Impl)) {}
/// <summary>
/// Replaces the contents of one <c>task</c> object with another.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// As <c>task</c> behaves like a smart pointer, after a copy assignment, this <c>task</c> objects represents the same
/// actual task as <paramref name="_Other"/> does.
/// </remarks>
/**/
task& operator=(const task& _Other)
{
if (this != &_Other)
{
_M_Impl = _Other._M_Impl;
}
return *this;
}
/// <summary>
/// Replaces the contents of one <c>task</c> object with another.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// As <c>task</c> behaves like a smart pointer, after a copy assignment, this <c>task</c> objects represents the same
/// actual task as <paramref name="_Other"/> does.
/// </remarks>
/**/
task& operator=(task&& _Other)
{
if (this != &_Other)
{
_M_Impl = std::move(_Other._M_Impl);
}
return *this;
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task&lt;result_type&gt;</c>, where <c>result_type</c> is the type
/// of the result this task produces.
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo interface, are only available
/// to Windows Store apps.
/// <para>For more information on how to use task continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK gives us the expected result
auto then(const _Function& _Func) const -> typename details::_ContinuationTypeTraits<_Function, _ReturnType>::_TaskOfType
{
task_options _TaskOptions;
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(_CAPTURE_CALLSTACK());
return _ThenImpl<_ReturnType, _Function>(_Func, _TaskOptions);
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task&lt;result_type&gt;</c>, where <c>result_type</c> is the type
/// of the result this task produces.
/// </param>
/// <param name="_TaskOptions">
/// The task options include cancellation token, scheduler and continuation context. By default the former 3
/// options are inherited from the antecedent task
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo interface, are only available
/// to Windows Store apps.
/// <para>For more information on how to use task continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK gives us the expected result
auto then(const _Function& _Func, task_options _TaskOptions) const -> typename details::_ContinuationTypeTraits<_Function, _ReturnType>::_TaskOfType
{
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(_CAPTURE_CALLSTACK());
return _ThenImpl<_ReturnType, _Function>(_Func, _TaskOptions);
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task&lt;result_type&gt;</c>, where <c>result_type</c> is the type
/// of the result this task produces.
/// </param>
/// <param name="_CancellationToken">
/// The cancellation token to associate with the continuation task. A continuation task that is created without a cancellation token will inherit
/// the token of its antecedent task.
/// </param>
/// <param name="_ContinuationContext">
/// A variable that specifies where the continuation should execute. This variable is only useful when used in a Windows Store
/// style app. For more information, see <see cref="task_continuation_context Class">task_continuation_context</see>
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo interface, are only available
/// to Windows Store apps.
/// <para>For more information on how to use task continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK gives us the expected result
auto then(const _Function& _Func, cancellation_token _CancellationToken, task_continuation_context _ContinuationContext) const -> typename details::_ContinuationTypeTraits<_Function, _ReturnType>::_TaskOfType
{
task_options _TaskOptions(_CancellationToken, _ContinuationContext);
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(_CAPTURE_CALLSTACK());
return _ThenImpl<_ReturnType, _Function>(_Func, _TaskOptions);
}
/// <summary>
/// Waits for this task to reach a terminal state. It is possible for <c>wait</c> to execute the task inline, if all of the tasks
/// dependencies are satisfied, and it has not already been picked up for execution by a background worker.
/// </summary>
/// <returns>
/// A <c>task_status</c> value which could be either <c>completed</c> or <c>canceled</c>. If the task encountered an exception
/// during execution, or an exception was propagated to it from an antecedent task, <c>wait</c> will throw that exception.
/// </returns>
/**/
task_status wait() const
{
if (!_M_Impl)
{
throw invalid_operation("wait() cannot be called on a default constructed task.");
}
return _M_Impl->_Wait();
}
/// <summary>
/// Returns the result this task produced. If the task is not in a terminal state, a call to <c>get</c> will wait for the task to
/// finish. This method does not return a value when called on a task with a <c>result_type</c> of <c>void</c>.
/// </summary>
/// <returns>
/// The result of the task.
/// </returns>
/// <remarks>
/// If the task is canceled, a call to <c>get</c> will throw a <see cref="task_canceled Class">task_canceled</see> exception. If the task
/// encountered an different exception or an exception was propagated to it from an antecedent task, a call to <c>get</c> will throw that exception.
/// </remarks>
/**/
_ReturnType get() const
{
if (!_M_Impl)
{
throw invalid_operation("get() cannot be called on a default constructed task.");
}
if (_M_Impl->_Wait() == canceled)
{
throw task_canceled();
}
return _M_Impl->_GetResult();
}
/// <summary>
/// Determines if the task is completed.
/// </summary>
/// <returns>
/// True if the task has completed, false otherwise.
/// </returns>
/// <remarks>
/// The function returns true if the task is completed or canceled (with or without user exception).
/// </remarks>
bool is_done() const
{
if (!_M_Impl)
{
throw invalid_operation("is_done() cannot be called on a default constructed task.");
}
return _M_Impl->_IsDone();
}
/// <summary>
/// Returns the scheduler for this task
/// </summary>
/// <returns>
/// A pointer to the scheduler
/// </returns>
scheduler_ptr scheduler() const
{
if (!_M_Impl)
{
throw invalid_operation("scheduler() cannot be called on a default constructed task.");
}
return _M_Impl->_GetScheduler();
}
/// <summary>
/// Determines whether the task unwraps a Windows Runtime <c>IAsyncInfo</c> interface or is descended from such a task.
/// </summary>
/// <returns>
/// <c>true</c> if the task unwraps an <c>IAsyncInfo</c> interface or is descended from such a task, <c>false</c> otherwise.
/// </returns>
/**/
bool is_apartment_aware() const
{
if (!_M_Impl)
{
throw invalid_operation("is_apartment_aware() cannot be called on a default constructed task.");
}
return _M_Impl->_IsApartmentAware();
}
/// <summary>
/// Determines whether two <c>task</c> objects represent the same internal task.
/// </summary>
/// <returns>
/// <c>true</c> if the objects refer to the same underlying task, and <c>false</c> otherwise.
/// </returns>
/**/
bool operator==(const task<_ReturnType>& _Rhs) const
{
return (_M_Impl == _Rhs._M_Impl);
}
/// <summary>
/// Determines whether two <c>task</c> objects represent different internal tasks.
/// </summary>
/// <returns>
/// <c>true</c> if the objects refer to different underlying tasks, and <c>false</c> otherwise.
/// </returns>
/**/
bool operator!=(const task<_ReturnType>& _Rhs) const
{
return !operator==(_Rhs);
}
/// <summary>
/// Create an underlying task implementation.
/// </summary>
void _CreateImpl(details::_CancellationTokenState * _Ct, scheduler_ptr _Scheduler)
{
_ASSERTE(_Ct != nullptr);
_M_Impl = details::_Task_ptr<_ReturnType>::_Make(_Ct, _Scheduler);
if (_Ct != details::_CancellationTokenState::_None())
{
_M_Impl->_RegisterCancellation(_M_Impl);
}
}
/// <summary>
/// Return the underlying implementation for this task.
/// </summary>
const typename details::_Task_ptr<_ReturnType>::_Type & _GetImpl() const
{
return _M_Impl;
}
/// <summary>
/// Set the implementation of the task to be the supplied implementaion.
/// </summary>
void _SetImpl(const typename details::_Task_ptr<_ReturnType>::_Type & _Impl)
{
_ASSERTE(!_M_Impl);
_M_Impl = _Impl;
}
/// <summary>
/// Set the implementation of the task to be the supplied implementaion using a move instead of a copy.
/// </summary>
void _SetImpl(typename details::_Task_ptr<_ReturnType>::_Type && _Impl)
{
_ASSERTE(!_M_Impl);
_M_Impl = std::move(_Impl);
}
/// <summary>
/// Sets a property determining whether the task is apartment aware.
/// </summary>
void _SetAsync(bool _Async = true)
{
_GetImpl()->_SetAsync(_Async);
}
/// <summary>
/// Sets a field in the task impl to the return callstack for calls to the task constructors and the then method.
/// </summary>
void _SetTaskCreationCallstack(const details::_TaskCreationCallstack &_callstack)
{
_GetImpl()->_SetTaskCreationCallstack(_callstack);
}
/// <summary>
/// An internal version of then that takes additional flags and always execute the continuation inline by default.
/// When _ForceInline is set to false, continuations inlining will be limited to default _DefaultAutoInline.
/// This function is Used for runtime internal continuations only.
/// </summary>
template<typename _Function>
auto _Then(const _Function& _Func, details::_CancellationTokenState *_PTokenState,
details::_TaskInliningMode_t _InliningMode = details::_ForceInline) const -> typename details::_ContinuationTypeTraits<_Function, _ReturnType>::_TaskOfType
{
// inherit from antecedent
auto _Scheduler = _GetImpl()->_GetScheduler();
return _ThenImpl<_ReturnType, _Function>(_Func, _PTokenState, task_continuation_context::use_default(), _Scheduler, _CAPTURE_CALLSTACK(), _InliningMode);
}
private:
template <typename T> friend class task;
// The task handle type used to construct an 'initial task' - a task with no dependents.
template <typename _InternalReturnType, typename _Function, typename _TypeSelection>
struct _InitialTaskHandle :
details::_PPLTaskHandle<_ReturnType, _InitialTaskHandle<_InternalReturnType, _Function, _TypeSelection>, details::_UnrealizedChore_t>
{
_Function _M_function;
_InitialTaskHandle(const typename details::_Task_ptr<_ReturnType>::_Type & _TaskImpl, const _Function & _func)
: details::_PPLTaskHandle<_ReturnType, _InitialTaskHandle<_InternalReturnType, _Function, _TypeSelection>, details::_UnrealizedChore_t>::_PPLTaskHandle(_TaskImpl)
, _M_function(_func)
{
}
virtual ~_InitialTaskHandle() {}
template <typename _Func>
auto _LogWorkItemAndInvokeUserLambda(_Func && _func) const -> decltype(_func())
{
details::_TaskWorkItemRAIILogger _LogWorkItem(this->_M_pTask->_M_taskEventLogger);
return _func();
}
void _Perform() const
{
_Init(_TypeSelection());
}
void _SyncCancelAndPropagateException() const
{
this->_M_pTask->_Cancel(true);
}
//
// Overload 0: returns _InternalReturnType
//
// This is the most basic task with no unwrapping
//
void _Init(details::_TypeSelectorNoAsync) const
{
this->_M_pTask->_FinalizeAndRunContinuations(_LogWorkItemAndInvokeUserLambda(_Init_func_transformer<_InternalReturnType>::_Perform(_M_function)));
}
//
// Overload 1: returns IAsyncOperation<_InternalReturnType>^ (only uder /ZW)
// or
// returns task<_InternalReturnType>
//
// This is task whose functor returns an async operation or a task which will be unwrapped for continuation
// Depending on the output type, the right _AsyncInit gets invoked
//
void _Init(details::_TypeSelectorAsyncOperationOrTask) const
{
details::_Task_impl_base::_AsyncInit<_ReturnType, _InternalReturnType>(this->_M_pTask, _LogWorkItemAndInvokeUserLambda(_M_function));
}
#if defined (__cplusplus_winrt)
//
// Overload 2: returns IAsyncAction^
//
// This is task whose functor returns an async action which will be unwrapped for continuation
//
void _Init(details::_TypeSelectorAsyncAction) const
{
details::_Task_impl_base::_AsyncInit<_ReturnType, _InternalReturnType>(this->_M_pTask, ref new details::_IAsyncActionToAsyncOperationConverter(_LogWorkItemAndInvokeUserLambda(_M_function)));
}
//
// Overload 3: returns IAsyncOperationWithProgress<_InternalReturnType, _ProgressType>^
//
// This is task whose functor returns an async operation with progress which will be unwrapped for continuation
//
void _Init(details::_TypeSelectorAsyncOperationWithProgress) const
{
typedef details::_GetProgressType<decltype(_M_function())>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_ReturnType, _InternalReturnType>(this->_M_pTask,
ref new details::_IAsyncOperationWithProgressToAsyncOperationConverter<_InternalReturnType,_ProgressType>(_LogWorkItemAndInvokeUserLambda(_M_function)));
}
//
// Overload 4: returns IAsyncActionWithProgress<_ProgressType>^
//
// This is task whose functor returns an async action with progress which will be unwrapped for continuation
//
void _Init(details::_TypeSelectorAsyncActionWithProgress) const
{
typedef details::_GetProgressType<decltype(_M_function())>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_ReturnType, _InternalReturnType>(this->_M_pTask,
ref new details::_IAsyncActionWithProgressToAsyncOperationConverter<_ProgressType>(_LogWorkItemAndInvokeUserLambda(_M_function)));
}
#endif /* defined (__cplusplus_winrt) */
};
/// <summary>
/// The task handle type used to create a 'continuation task'.
/// </summary>
template <typename _InternalReturnType, typename _ContinuationReturnType, typename _Function, typename _IsTaskBased, typename _TypeSelection>
struct _ContinuationTaskHandle :
details::_PPLTaskHandle<typename details::_NormalizeVoidToUnitType<_ContinuationReturnType>::_Type,
_ContinuationTaskHandle<_InternalReturnType, _ContinuationReturnType, _Function, _IsTaskBased, _TypeSelection>, details::_ContinuationTaskHandleBase>
{
typedef typename details::_NormalizeVoidToUnitType<_ContinuationReturnType>::_Type _NormalizedContinuationReturnType;
typename details::_Task_ptr<_ReturnType>::_Type _M_ancestorTaskImpl;
_Function _M_function;
_ContinuationTaskHandle(const typename details::_Task_ptr<_ReturnType>::_Type & _AncestorImpl,
const typename details::_Task_ptr<_NormalizedContinuationReturnType>::_Type & _ContinuationImpl,
const _Function & _Func, const task_continuation_context & _Context, details::_TaskInliningMode_t _InliningMode)
: details::_PPLTaskHandle<typename details::_NormalizeVoidToUnitType<_ContinuationReturnType>::_Type,
_ContinuationTaskHandle<_InternalReturnType, _ContinuationReturnType, _Function, _IsTaskBased, _TypeSelection>, details::_ContinuationTaskHandleBase>
::_PPLTaskHandle(_ContinuationImpl)
, _M_ancestorTaskImpl(_AncestorImpl)
, _M_function(_Func)
{
this->_M_isTaskBasedContinuation = _IsTaskBased::value;
this->_M_continuationContext = _Context;
this->_M_continuationContext._Resolve(_AncestorImpl->_IsApartmentAware());
this->_M_inliningMode = _InliningMode;
}
virtual ~_ContinuationTaskHandle() {}
template <typename _Func, typename _Arg>
auto _LogWorkItemAndInvokeUserLambda(_Func && _func, _Arg && _value) const -> decltype(_func(std::forward<_Arg>(_value)))
{
details::_TaskWorkItemRAIILogger _LogWorkItem(this->_M_pTask->_M_taskEventLogger);
return _func(std::forward<_Arg>(_value));
}
void _Perform() const
{
_Continue(_IsTaskBased(), _TypeSelection());
}
void _SyncCancelAndPropagateException() const
{
if (_M_ancestorTaskImpl->_HasUserException())
{
// If the ancestor encountered an exception, transfer the exception to the continuation
// This traverses down the tree to propagate the exception.
this->_M_pTask->_CancelWithExceptionHolder(_M_ancestorTaskImpl->_GetExceptionHolder(), true);
}
else
{
// If the ancestor was canceled, then your own execution should be canceled.
// This traverses down the tree to cancel it.
this->_M_pTask->_Cancel(true);
}
}
//
// Overload 0-0: _InternalReturnType -> _TaskType
//
// This is a straight task continuation which simply invokes its target with the ancestor's completion argument
//
void _Continue(std::false_type, details::_TypeSelectorNoAsync) const
{
this->_M_pTask->_FinalizeAndRunContinuations(
_LogWorkItemAndInvokeUserLambda(_Continuation_func_transformer<_InternalReturnType, _ContinuationReturnType>::_Perform(_M_function), _M_ancestorTaskImpl->_GetResult()));
}
//
// Overload 0-1: _InternalReturnType -> IAsyncOperation<_TaskType>^ (only uder /ZW)
// or
// _InternalReturnType -> task<_TaskType>
//
// This is a straight task continuation which returns an async operation or a task which will be unwrapped for continuation
// Depending on the output type, the right _AsyncInit gets invoked
//
void _Continue(std::false_type, details::_TypeSelectorAsyncOperationOrTask) const
{
typedef typename details::_FunctionTypeTraits<_Function, _InternalReturnType>::_FuncRetType _FuncOutputType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
_LogWorkItemAndInvokeUserLambda(_Continuation_func_transformer<_InternalReturnType, _FuncOutputType>::_Perform(_M_function), _M_ancestorTaskImpl->_GetResult())
);
}
#if defined (__cplusplus_winrt)
//
// Overload 0-2: _InternalReturnType -> IAsyncAction^
//
// This is a straight task continuation which returns an async action which will be unwrapped for continuation
//
void _Continue(std::false_type, details::_TypeSelectorAsyncAction) const
{
typedef details::_FunctionTypeTraits<_Function, _InternalReturnType>::_FuncRetType _FuncOutputType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
ref new details::_IAsyncActionToAsyncOperationConverter(
_LogWorkItemAndInvokeUserLambda(_Continuation_func_transformer<_InternalReturnType, _FuncOutputType>::_Perform(_M_function), _M_ancestorTaskImpl->_GetResult())));
}
//
// Overload 0-3: _InternalReturnType -> IAsyncOperationWithProgress<_TaskType, _ProgressType>^
//
// This is a straight task continuation which returns an async operation with progress which will be unwrapped for continuation
//
void _Continue(std::false_type, details::_TypeSelectorAsyncOperationWithProgress) const
{
typedef details::_FunctionTypeTraits<_Function, _InternalReturnType>::_FuncRetType _FuncOutputType;
auto _OpWithProgress = _LogWorkItemAndInvokeUserLambda(_Continuation_func_transformer<_InternalReturnType, _FuncOutputType>::_Perform(_M_function), _M_ancestorTaskImpl->_GetResult());
typedef details::_GetProgressType<decltype(_OpWithProgress)>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
ref new details::_IAsyncOperationWithProgressToAsyncOperationConverter<_ContinuationReturnType, _ProgressType>(_OpWithProgress));
}
//
// Overload 0-4: _InternalReturnType -> IAsyncActionWithProgress<_ProgressType>^
//
// This is a straight task continuation which returns an async action with progress which will be unwrapped for continuation
//
void _Continue(std::false_type, details::_TypeSelectorAsyncActionWithProgress) const
{
typedef details::_FunctionTypeTraits<_Function, _InternalReturnType>::_FuncRetType _FuncOutputType;
auto _OpWithProgress = _LogWorkItemAndInvokeUserLambda(_Continuation_func_transformer<_InternalReturnType, _FuncOutputType>::_Perform(_M_function), _M_ancestorTaskImpl->_GetResult());
typedef details::_GetProgressType<decltype(_OpWithProgress)>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
ref new details::_IAsyncActionWithProgressToAsyncOperationConverter<_ProgressType>(_OpWithProgress));
}
#endif /* defined (__cplusplus_winrt) */
//
// Overload 1-0: task<_InternalReturnType> -> _TaskType
//
// This is an exception handling type of continuation which takes the task rather than the task's result.
//
void _Continue(std::true_type, details::_TypeSelectorNoAsync) const
{
typedef task<_InternalReturnType> _FuncInputType;
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
this->_M_pTask->_FinalizeAndRunContinuations(
_LogWorkItemAndInvokeUserLambda(_Continuation_func_transformer<_FuncInputType, _ContinuationReturnType>::_Perform(_M_function), std::move(_ResultTask)));
}
//
// Overload 1-1: task<_InternalReturnType> -> IAsyncOperation<_TaskType>^
// or
// task<_TaskType>
//
// This is an exception handling type of continuation which takes the task rather than
// the task's result. It also returns an async operation or a task which will be unwrapped
// for continuation
//
void _Continue(std::true_type, details::_TypeSelectorAsyncOperationOrTask) const
{
// The continuation takes a parameter of type task<_Input>, which is the same as the ancestor task.
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(this->_M_pTask,
_LogWorkItemAndInvokeUserLambda(_M_function, std::move(_ResultTask)));
}
#if defined (__cplusplus_winrt)
//
// Overload 1-2: task<_InternalReturnType> -> IAsyncAction^
//
// This is an exception handling type of continuation which takes the task rather than
// the task's result. It also returns an async action which will be unwrapped for continuation
//
void _Continue(std::true_type, details::_TypeSelectorAsyncAction) const
{
// The continuation takes a parameter of type task<_Input>, which is the same as the ancestor task.
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(this->_M_pTask,
ref new details::_IAsyncActionToAsyncOperationConverter(_LogWorkItemAndInvokeUserLambda(_M_function, std::move(_ResultTask))));
}
//
// Overload 1-3: task<_InternalReturnType> -> IAsyncOperationWithProgress<_TaskType, _ProgressType>^
//
// This is an exception handling type of continuation which takes the task rather than
// the task's result. It also returns an async operation with progress which will be unwrapped
// for continuation
//
void _Continue(std::true_type, details::_TypeSelectorAsyncOperationWithProgress) const
{
// The continuation takes a parameter of type task<_Input>, which is the same as the ancestor task.
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
typedef details::_GetProgressType<decltype(_M_function(_ResultTask))>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(this->_M_pTask,
ref new details::_IAsyncOperationWithProgressToAsyncOperationConverter<_ContinuationReturnType, _ProgressType>(
_LogWorkItemAndInvokeUserLambda(_M_function, std::move(_ResultTask))));
}
//
// Overload 1-4: task<_InternalReturnType> -> IAsyncActionWithProgress<_ProgressType>^
//
// This is an exception handling type of continuation which takes the task rather than
// the task's result. It also returns an async operation with progress which will be unwrapped
// for continuation
//
void _Continue(std::true_type, details::_TypeSelectorAsyncActionWithProgress) const
{
// The continuation takes a parameter of type task<_Input>, which is the same as the ancestor task.
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
typedef details::_GetProgressType<decltype(_M_function(_ResultTask))>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(this->_M_pTask,
ref new details::_IAsyncActionWithProgressToAsyncOperationConverter<_ProgressType>(
_LogWorkItemAndInvokeUserLambda(_M_function, std::move(_ResultTask))));
}
#endif /* defined (__cplusplus_winrt) */
};
/// <summary>
/// Initializes a task using a lambda, function pointer or function object.
/// </summary>
template<typename _InternalReturnType, typename _Function>
void _TaskInitWithFunctor(const _Function& _Func)
{
typedef typename details::_InitFunctorTypeTraits<_InternalReturnType, decltype(_Func())> _Async_type_traits;
_M_Impl->_M_fFromAsync = _Async_type_traits::_IsAsyncTask;
_M_Impl->_M_fUnwrappedTask = _Async_type_traits::_IsUnwrappedTaskOrAsync;
_M_Impl->_M_taskEventLogger._LogScheduleTask(false);
_M_Impl->_ScheduleTask(new _InitialTaskHandle<_InternalReturnType, _Function, typename _Async_type_traits::_AsyncKind>(_GetImpl(), _Func), details::_NoInline);
}
/// <summary>
/// Initializes a task using a task completion event.
/// </summary>
void _TaskInitNoFunctor(task_completion_event<_ReturnType>& _Event)
{
_Event._RegisterTask(_M_Impl);
}
#if defined (__cplusplus_winrt)
/// <summary>
/// Initializes a task using an asynchronous operation IAsyncOperation<T>^
/// </summary>
void _TaskInitAsyncOp(Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value>^ _AsyncOp)
{
_M_Impl->_M_fFromAsync = true;
// Mark this task as started here since we can set the state in the constructor without acquiring a lock. Once _AsyncInit
// returns a completion could execute concurrently and the task must be fully initialized before that happens.
_M_Impl->_M_TaskState = details::_Task_impl_base::_Started;
// Pass the shared pointer into _AsyncInit for storage in the Async Callback.
details::_Task_impl_base::_AsyncInit<_ReturnType, _ReturnType>(_M_Impl, _AsyncOp);
}
/// <summary>
/// Initializes a task using an asynchronous operation IAsyncOperation<T>^
/// </summary>
void _TaskInitNoFunctor(Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value>^ _AsyncOp)
{
_TaskInitAsyncOp(_AsyncOp);
}
/// <summary>
/// Initializes a task using an asynchronous operation with progress IAsyncOperationWithProgress<T, P>^
/// </summary>
template<typename _Progress>
void _TaskInitNoFunctor(Windows::Foundation::IAsyncOperationWithProgress<typename details::_ValueTypeOrRefType<_ReturnType>::_Value, _Progress>^ _AsyncOp)
{
_TaskInitAsyncOp(ref new details::_IAsyncOperationWithProgressToAsyncOperationConverter<typename details::_ValueTypeOrRefType<_ReturnType>::_Value, _Progress>(_AsyncOp));
}
#endif /* defined (__cplusplus_winrt) */
/// <summary>
/// Initializes a task using a callable object.
/// </summary>
template<typename _Function>
void _TaskInitMaybeFunctor(_Function & _Func, std::true_type)
{
_TaskInitWithFunctor<_ReturnType, _Function>(_Func);
}
/// <summary>
/// Initializes a task using a non-callable object.
/// </summary>
template<typename _Ty>
void _TaskInitMaybeFunctor(_Ty & _Param, std::false_type)
{
_TaskInitNoFunctor(_Param);
}
template<typename _InternalReturnType, typename _Function>
auto _ThenImpl(const _Function& _Func, const task_options& _TaskOptions) const -> typename details::_ContinuationTypeTraits<_Function, _InternalReturnType>::_TaskOfType
{
if (!_M_Impl)
{
throw invalid_operation("then() cannot be called on a default constructed task.");
}
details::_CancellationTokenState *_PTokenState = _TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _Scheduler = _TaskOptions.has_scheduler() ? _TaskOptions.get_scheduler() : _GetImpl()->_GetScheduler();
auto _CreationStack = details::_get_internal_task_options(_TaskOptions)._M_hasPresetCreationCallstack ? details::_get_internal_task_options(_TaskOptions)._M_presetCreationCallstack : details::_TaskCreationCallstack();
return _ThenImpl<_InternalReturnType, _Function>(_Func, _PTokenState, _TaskOptions.get_continuation_context(), _Scheduler, _CreationStack);
}
/// <summary>
/// The one and only implementation of then for void and non-void tasks.
/// </summary>
template<typename _InternalReturnType, typename _Function>
auto _ThenImpl(const _Function& _Func, details::_CancellationTokenState *_PTokenState, const task_continuation_context& _ContinuationContext, scheduler_ptr _Scheduler, details::_TaskCreationCallstack _CreationStack,
details::_TaskInliningMode_t _InliningMode = details::_NoInline) const -> typename details::_ContinuationTypeTraits<_Function, _InternalReturnType>::_TaskOfType
{
if (!_M_Impl)
{
throw invalid_operation("then() cannot be called on a default constructed task.");
}
typedef details::_FunctionTypeTraits<_Function, _InternalReturnType> _Function_type_traits;
typedef details::_TaskTypeTraits<typename _Function_type_traits::_FuncRetType> _Async_type_traits;
typedef typename _Async_type_traits::_TaskRetType _TaskType;
//
// A **nullptr** token state indicates that it was not provided by the user. In this case, we inherit the antecedent's token UNLESS this is a
// an exception handling continuation. In that case, we break the chain with a _None. That continuation is never canceled unless the user
// explicitly passes the same token.
//
if (_PTokenState == nullptr)
{
if (_Function_type_traits::_Takes_task::value)
{
_PTokenState = details::_CancellationTokenState::_None();
}
else
{
_PTokenState = _GetImpl()->_M_pTokenState;
}
}
task<_TaskType> _ContinuationTask;
_ContinuationTask._CreateImpl(_PTokenState, _Scheduler);
_ContinuationTask._GetImpl()->_M_fFromAsync = (_GetImpl()->_M_fFromAsync || _Async_type_traits::_IsAsyncTask);
_ContinuationTask._GetImpl()->_M_fUnwrappedTask = _Async_type_traits::_IsUnwrappedTaskOrAsync;
_ContinuationTask._SetTaskCreationCallstack(_CreationStack);
_GetImpl()->_ScheduleContinuation(new _ContinuationTaskHandle<_InternalReturnType, _TaskType, _Function, typename _Function_type_traits::_Takes_task, typename _Async_type_traits::_AsyncKind>(
_GetImpl(), _ContinuationTask._GetImpl(), _Func, _ContinuationContext, _InliningMode));
return _ContinuationTask;
}
// The underlying implementation for this task
typename details::_Task_ptr<_ReturnType>::_Type _M_Impl;
};
/// <summary>
/// The Parallel Patterns Library (PPL) <c>task</c> class. A <c>task</c> object represents work that can be executed asynchronously,
/// and concurrently with other tasks and parallel work produced by parallel algorithms in the Concurrency Runtime. It produces
/// a result of type <typeparamref name="_ResultType"/> on successful completion. Tasks of type <c>task&lt;void&gt;</c> produce no result.
/// A task can be waited upon and canceled independently of other tasks. It can also be composed with other tasks using
/// continuations(<c>then</c>), and join(<c>when_all</c>) and choice(<c>when_any</c>) patterns.
/// </summary>
/// <remarks>
/// For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.
/// </remarks>
/**/
template<>
class task<void>
{
public:
/// <summary>
/// The type of the result an object of this class produces.
/// </summary>
/**/
typedef void result_type;
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within containers.
/// A default constructed task cannot be used until you assign a valid task to it. Methods such as <c>get</c>, <c>wait</c> or <c>then</c>
/// will throw an <see cref="invalid_argument Class">invalid_argument</see> exception when called on a default constructed task.
/// <para>A task that is created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the task
/// completion event is set.</para>
/// <para>The version of the constructor that takes a cancellation token creates a task that can be canceled using the
/// <c>cancellation_token_source</c> the token was obtained from. Tasks created without a cancellation token are not cancelable.</para>
/// <para>Tasks created from a <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes. Similarly, tasks created
/// from a lamda that returns a <c>task&lt;result_type&gt;</c> reach their terminal state when the inner task reaches its terminal state,
/// and not when the lamda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by multiple threads
/// without the need for locks.</para>
/// <para>The constructor overloads that take a Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available
/// to Windows Store apps.</para>
/// <para>For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
task() : _M_unitTask()
{
// The default constructor should create a task with a nullptr impl. This is a signal that the
// task is not usable and should throw if any wait(), get() or then() APIs are used.
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda, a function object, a <c>task_completion_event&lt;result_type&gt;</c>
/// object, or a Windows::Foundation::IAsyncInfo if you are using tasks in your Windows Store app. The lambda or function
/// object should be a type equivalent to <c>std::function&lt;X(void)&gt;</c>, where X can be a variable of type <c>result_type</c>,
/// <c>task&lt;result_type&gt;</c>, or a Windows::Foundation::IAsyncInfo in Windows Store apps.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within containers.
/// A default constructed task cannot be used until you assign a valid task to it. Methods such as <c>get</c>, <c>wait</c> or <c>then</c>
/// will throw an <see cref="invalid_argument Class">invalid_argument</see> exception when called on a default constructed task.
/// <para>A task that is created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the task
/// completion event is set.</para>
/// <para>The version of the constructor that takes a cancellation token creates a task that can be canceled using the
/// <c>cancellation_token_source</c> the token was obtained from. Tasks created without a cancellation token are not cancelable.</para>
/// <para>Tasks created from a <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes. Similarly, tasks created
/// from a lamda that returns a <c>task&lt;result_type&gt;</c> reach their terminal state when the inner task reaches its terminal state,
/// and not when the lamda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by multiple threads
/// without the need for locks.</para>
/// <para>The constructor overloads that take a Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available
/// to Windows Store apps.</para>
/// <para>For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Ty>
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK gives us the expected result
explicit task(_Ty _Param, const task_options& _TaskOptions = task_options())
{
details::_ValidateTaskConstructorArgs<void,_Ty>(_Param);
_M_unitTask._CreateImpl(_TaskOptions.get_cancellation_token()._GetImplValue(), _TaskOptions.get_scheduler());
// Do not move the next line out of this function. It is important that _CAPTURE_CALLSTACK() evaluate to the the call site of the task constructor.
_M_unitTask._SetTaskCreationCallstack(details::_get_internal_task_options(_TaskOptions)._M_hasPresetCreationCallstack ? details::_get_internal_task_options(_TaskOptions)._M_presetCreationCallstack : _CAPTURE_CALLSTACK());
_TaskInitMaybeFunctor(_Param, details::_IsCallable(_Param,0));
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within containers.
/// A default constructed task cannot be used until you assign a valid task to it. Methods such as <c>get</c>, <c>wait</c> or <c>then</c>
/// will throw an <see cref="invalid_argument Class">invalid_argument</see> exception when called on a default constructed task.
/// <para>A task that is created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the task
/// completion event is set.</para>
/// <para>The version of the constructor that takes a cancellation token creates a task that can be canceled using the
/// <c>cancellation_token_source</c> the token was obtained from. Tasks created without a cancellation token are not cancelable.</para>
/// <para>Tasks created from a <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes. Similarly, tasks created
/// from a lamda that returns a <c>task&lt;result_type&gt;</c> reach their terminal state when the inner task reaches its terminal state,
/// and not when the lamda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by multiple threads
/// without the need for locks.</para>
/// <para>The constructor overloads that take a Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available
/// to Windows Store apps.</para>
/// <para>For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
task(const task& _Other): _M_unitTask(_Other._M_unitTask){}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within containers.
/// A default constructed task cannot be used until you assign a valid task to it. Methods such as <c>get</c>, <c>wait</c> or <c>then</c>
/// will throw an <see cref="invalid_argument Class">invalid_argument</see> exception when called on a default constructed task.
/// <para>A task that is created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the task
/// completion event is set.</para>
/// <para>The version of the constructor that takes a cancellation token creates a task that can be canceled using the
/// <c>cancellation_token_source</c> the token was obtained from. Tasks created without a cancellation token are not cancelable.</para>
/// <para>Tasks created from a <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes. Similarly, tasks created
/// from a lamda that returns a <c>task&lt;result_type&gt;</c> reach their terminal state when the inner task reaches its terminal state,
/// and not when the lamda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by multiple threads
/// without the need for locks.</para>
/// <para>The constructor overloads that take a Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available
/// to Windows Store apps.</para>
/// <para>For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
task(task&& _Other) : _M_unitTask(std::move(_Other._M_unitTask)) {}
/// <summary>
/// Replaces the contents of one <c>task</c> object with another.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// As <c>task</c> behaves like a smart pointer, after a copy assignment, this <c>task</c> objects represents the same
/// actual task as <paramref name="_Other"/> does.
/// </remarks>
/**/
task& operator=(const task& _Other)
{
if (this != &_Other)
{
_M_unitTask = _Other._M_unitTask;
}
return *this;
}
/// <summary>
/// Replaces the contents of one <c>task</c> object with another.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// As <c>task</c> behaves like a smart pointer, after a copy assignment, this <c>task</c> objects represents the same
/// actual task as <paramref name="_Other"/> does.
/// </remarks>
/**/
task& operator=(task&& _Other)
{
if (this != &_Other)
{
_M_unitTask = std::move(_Other._M_unitTask);
}
return *this;
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task&lt;result_type&gt;</c>, where <c>result_type</c> is the type
/// of the result this task produces.
/// </param>
/// <param name="_CancellationToken">
/// The cancellation token to associate with the continuation task. A continuation task that is created without a cancellation token will inherit
/// the token of its antecedent task.
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo interface, are only available
/// to Windows Store apps.
/// <para>For more information on how to use task continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK gives us the expected result
auto then(const _Function& _Func, task_options _TaskOptions = task_options()) const -> typename details::_ContinuationTypeTraits<_Function, void>::_TaskOfType
{
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(_CAPTURE_CALLSTACK());
return _M_unitTask._ThenImpl<void, _Function>(_Func, _TaskOptions);
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task&lt;result_type&gt;</c>, where <c>result_type</c> is the type
/// of the result this task produces.
/// </param>
/// <param name="_CancellationToken">
/// The cancellation token to associate with the continuation task. A continuation task that is created without a cancellation token will inherit
/// the token of its antecedent task.
/// </param>
/// <param name="_ContinuationContext">
/// A variable that specifies where the continuation should execute. This variable is only useful when used in a Windows Store
/// style app. For more information, see <see cref="task_continuation_context Class">task_continuation_context</see>
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo interface, are only available
/// to Windows Store apps.
/// <para>For more information on how to use task continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the _CAPTURE_CALLSTACK gives us the expected result
auto then(const _Function& _Func, cancellation_token _CancellationToken, task_continuation_context _ContinuationContext) const -> typename details::_ContinuationTypeTraits<_Function, void>::_TaskOfType
{
task_options _TaskOptions(_CancellationToken, _ContinuationContext);
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(_CAPTURE_CALLSTACK());
return _M_unitTask._ThenImpl<void, _Function>(_Func, _TaskOptions);
}
/// <summary>
/// Waits for this task to reach a terminal state. It is possible for <c>wait</c> to execute the task inline, if all of the tasks
/// dependencies are satisfied, and it has not already been picked up for execution by a background worker.
/// </summary>
/// <returns>
/// A <c>task_status</c> value which could be either <c>completed</c> or <c>canceled</c>. If the task encountered an exception
/// during execution, or an exception was propagated to it from an antecedent task, <c>wait</c> will throw that exception.
/// </returns>
/**/
task_status wait() const
{
return _M_unitTask.wait();
}
/// <summary>
/// Returns the result this task produced. If the task is not in a terminal state, a call to <c>get</c> will wait for the task to
/// finish. This method does not return a value when called on a task with a <c>result_type</c> of <c>void</c>.
/// </summary>
/// <remarks>
/// If the task is canceled, a call to <c>get</c> will throw a <see cref="task_canceled Class">task_canceled</see> exception. If the task
/// encountered an different exception or an exception was propagated to it from an antecedent task, a call to <c>get</c> will throw that exception.
/// </remarks>
/**/
void get() const
{
_M_unitTask.get();
}
/// <summary>
/// Determines if the task is completed.
/// </summary>
/// <returns>
/// True if the task has completed, false otherwise.
/// </returns>
/// <remarks>
/// The function returns true if the task is completed or canceled (with or without user exception).
/// </remarks>
bool is_done() const
{
return _M_unitTask.is_done();
}
/// <summary>
/// Returns the scheduler for this task
/// </summary>
/// <returns>
/// A pointer to the scheduler
/// </returns>
scheduler_ptr scheduler() const
{
return _M_unitTask.scheduler();
}
/// <summary>
/// Determines whether the task unwraps a Windows Runtime <c>IAsyncInfo</c> interface or is descended from such a task.
/// </summary>
/// <returns>
/// <c>true</c> if the task unwraps an <c>IAsyncInfo</c> interface or is descended from such a task, <c>false</c> otherwise.
/// </returns>
/**/
bool is_apartment_aware() const
{
return _M_unitTask.is_apartment_aware();
}
/// <summary>
/// Determines whether two <c>task</c> objects represent the same internal task.
/// </summary>
/// <returns>
/// <c>true</c> if the objects refer to the same underlying task, and <c>false</c> otherwise.
/// </returns>
/**/
bool operator==(const task<void>& _Rhs) const
{
return (_M_unitTask == _Rhs._M_unitTask);
}
/// <summary>
/// Determines whether two <c>task</c> objects represent different internal tasks.
/// </summary>
/// <returns>
/// <c>true</c> if the objects refer to different underlying tasks, and <c>false</c> otherwise.
/// </returns>
/**/
bool operator!=(const task<void>& _Rhs) const
{
return !operator==(_Rhs);
}
/// <summary>
/// Create an underlying task implementation.
/// </summary>
void _CreateImpl(details::_CancellationTokenState * _Ct, scheduler_ptr _Scheduler)
{
_M_unitTask._CreateImpl(_Ct, _Scheduler);
}
/// <summary>
/// Return the underlying implementation for this task.
/// </summary>
const details::_Task_ptr<details::_Unit_type>::_Type & _GetImpl() const
{
return _M_unitTask._M_Impl;
}
/// <summary>
/// Set the implementation of the task to be the supplied implementaion.
/// </summary>
void _SetImpl(const details::_Task_ptr<details::_Unit_type>::_Type & _Impl)
{
_M_unitTask._SetImpl(_Impl);
}
/// <summary>
/// Set the implementation of the task to be the supplied implementaion using a move instead of a copy.
/// </summary>
void _SetImpl(details::_Task_ptr<details::_Unit_type>::_Type && _Impl)
{
_M_unitTask._SetImpl(std::move(_Impl));
}
/// <summary>
/// Sets a property determining whether the task is apartment aware.
/// </summary>
void _SetAsync(bool _Async = true)
{
_M_unitTask._SetAsync(_Async);
}
/// <summary>
/// Sets a field in the task impl to the return callstack for calls to the task constructors and the then method.
/// </summary>
void _SetTaskCreationCallstack(const details::_TaskCreationCallstack &_callstack)
{
_M_unitTask._SetTaskCreationCallstack(_callstack);
}
/// <summary>
/// An internal version of then that takes additional flags and executes the continuation inline. Used for runtime internal continuations only.
/// </summary>
template<typename _Function>
auto _Then(const _Function& _Func, details::_CancellationTokenState *_PTokenState,
details::_TaskInliningMode_t _InliningMode = details::_ForceInline) const -> typename details::_ContinuationTypeTraits<_Function, void>::_TaskOfType
{
// inherit from antecedent
auto _Scheduler = _GetImpl()->_GetScheduler();
return _M_unitTask._ThenImpl<void, _Function>(_Func, _PTokenState, task_continuation_context::use_default(), _Scheduler, _CAPTURE_CALLSTACK(), _InliningMode);
}
private:
template <typename T> friend class task;
template <typename T> friend class task_completion_event;
/// <summary>
/// Initializes a task using a task completion event.
/// </summary>
void _TaskInitNoFunctor(task_completion_event<void>& _Event)
{
_M_unitTask._TaskInitNoFunctor(_Event._M_unitEvent);
}
#if defined (__cplusplus_winrt)
/// <summary>
/// Initializes a task using an asynchronous action IAsyncAction^
/// </summary>
void _TaskInitNoFunctor(Windows::Foundation::IAsyncAction^ _AsyncAction)
{
_M_unitTask._TaskInitAsyncOp(ref new details::_IAsyncActionToAsyncOperationConverter(_AsyncAction));
}
/// <summary>
/// Initializes a task using an asynchronous action with progress IAsyncActionWithProgress<_P>^
/// </summary>
template<typename _P>
void _TaskInitNoFunctor(Windows::Foundation::IAsyncActionWithProgress<_P>^ _AsyncActionWithProgress)
{
_M_unitTask._TaskInitAsyncOp(ref new details::_IAsyncActionWithProgressToAsyncOperationConverter<_P>(_AsyncActionWithProgress));
}
#endif /* defined (__cplusplus_winrt) */
/// <summary>
/// Initializes a task using a callable object.
/// </summary>
template<typename _Function>
void _TaskInitMaybeFunctor(_Function & _Func, std::true_type)
{
_M_unitTask._TaskInitWithFunctor<void, _Function>(_Func);
}
/// <summary>
/// Initializes a task using a non-callable object.
/// </summary>
template<typename _T>
void _TaskInitMaybeFunctor(_T & _Param, std::false_type)
{
_TaskInitNoFunctor(_Param);
}
// The void task contains a task of a dummy type so common code can be used for tasks with void and non-void results.
task<details::_Unit_type> _M_unitTask;
};
namespace details
{
/// <summary>
/// The following type traits are used for the create_task function.
/// </summary>
#if defined (__cplusplus_winrt)
// Unwrap functions for asyncOperations
template<typename _Ty>
_Ty _GetUnwrappedType(Windows::Foundation::IAsyncOperation<_Ty>^);
void _GetUnwrappedType(Windows::Foundation::IAsyncAction^);
template<typename _Ty, typename _Progress>
_Ty _GetUnwrappedType(Windows::Foundation::IAsyncOperationWithProgress<_Ty, _Progress>^);
template<typename _Progress>
void _GetUnwrappedType(Windows::Foundation::IAsyncActionWithProgress<_Progress>^);
#endif /* defined (__cplusplus_winrt) */
// Unwrap task<T>
template<typename _Ty>
_Ty _GetUnwrappedType(task<_Ty>);
// Unwrap all supportted types
template<typename _Ty>
auto _GetUnwrappedReturnType(_Ty _Arg, int) -> decltype(_GetUnwrappedType(_Arg));
// fallback
template<typename _Ty>
_Ty _GetUnwrappedReturnType(_Ty, ...);
/// <summary>
/// <c>_GetTaskType</c> functions will retrieve task type <c>T</c> in <c>task[T](Arg)</c>,
/// for given constructor argument <c>Arg</c> and its property "callable".
/// It will automatically unwrap argument to get the final return type if necessary.
/// </summary>
// Non-Callable
template<typename _Ty>
_Ty _GetTaskType(task_completion_event<_Ty>, std::false_type);
// Non-Callable
template<typename _Ty>
auto _GetTaskType(_Ty _NonFunc, std::false_type) -> decltype(_GetUnwrappedType(_NonFunc));
// Callable
template<typename _Ty>
auto _GetTaskType(_Ty _Func, std::true_type) -> decltype(_GetUnwrappedReturnType(_Func(), 0));
// Special callable returns void
void _GetTaskType(std::function<void()>, std::true_type);
struct _BadArgType{};
template<typename _Ty>
auto _FilterValidTaskType(_Ty _Param, int) -> decltype(_GetTaskType(_Param, _IsCallable(_Param, 0)));
template<typename _Ty>
_BadArgType _FilterValidTaskType(_Ty _Param, ...);
template<typename _Ty>
struct _TaskTypeFromParam
{
typedef decltype(_FilterValidTaskType(stdx::declval<_Ty>(), 0)) _Type;
};
} // namespace details
/// <summary>
/// Creates a PPL <see cref="task Class">task</see> object. <c>create_task</c> can be used anywhere you would have used a task constructor.
/// It is provided mainly for convenience, because it allows use of the <c>auto</c> keyword while creating tasks.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda or function object, a <c>task_completion_event</c>
/// object, a different <c>task</c> object, or a Windows::Foundation::IAsyncInfo interface if you are using tasks in your Windows Store app.
/// </param>
/// <returns>
/// A new task of type <c>T</c>, that is inferred from <paramref name="_Param"/>.
/// </returns>
/// <remarks>
/// The first overload behaves like a task constructor that takes a single parameter.
/// <para>The second overload associates the cancellation token provided with the newly created task. If you use this overload you are not
/// allowed to pass in a different <c>task</c> object as the first parameter.</para>
/// <para>The type of the returned task is inferred from the first parameter to the function. If <paramref name="_Param"/> is a <c>task_completion_event&lt;T&gt;</c>,
/// a <c>task&lt;T&gt;</c>, or a functor that returns either type <c>T</c> or <c>task&lt;T&gt;</c>, the type of the created task is <c>task&lt;T&gt;</c>.</para>
/// <para>In a Windows Store app, if <paramref name="_Param"/> is of type Windows::Foundation::IAsyncOperation&lt;T&gt;^ or
/// Windows::Foundation::IAsyncOperationWithProgress&lt;T,P&gt;^, or a functor that returns either of those types, the created task will be of type <c>task&lt;T&gt;</c>.
/// If <paramref name="_Param"/> is of type Windows::Foundation::IAsyncAction^ or Windows::Foundation::IAsyncActionWithProgress&lt;P&gt;^, or a functor
/// that returns either of those types, the created task will have type <c>task&lt;void&gt;</c>.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _Ty>
__declspec(noinline)
auto create_task(_Ty _Param, task_options _TaskOptions = task_options()) -> task<typename details::_TaskTypeFromParam<_Ty>::_Type>
{
static_assert(!std::is_same<typename details::_TaskTypeFromParam<_Ty>::_Type,details::_BadArgType>::value,
#if defined (__cplusplus_winrt)
"incorrect argument for create_task; can be a callable object, an asynchronous operation, or a task_completion_event"
#else /* defined (__cplusplus_winrt) */
"incorrect argument for create_task; can be a callable object or a task_completion_event"
#endif /* defined (__cplusplus_winrt) */
);
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(_CAPTURE_CALLSTACK());
task<typename details::_TaskTypeFromParam<_Ty>::_Type> _CreatedTask(_Param, _TaskOptions);
return _CreatedTask;
}
/// <summary>
/// Creates a PPL <see cref="task Class">task</see> object. <c>create_task</c> can be used anywhere you would have used a task constructor.
/// It is provided mainly for convenience, because it allows use of the <c>auto</c> keyword while creating tasks.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda or function object, a <c>task_completion_event</c>
/// object, a different <c>task</c> object, or a Windows::Foundation::IAsyncInfo interface if you are using tasks in your Windows Store app.
/// </param>
/// <param name="_Token">
/// The cancellation token to associate with the task. When the source for this token is canceled, cancellation will be requested on the task.
/// </param>
/// <returns>
/// A new task of type <c>T</c>, that is inferred from <paramref name="_Param"/>.
/// </returns>
/// <remarks>
/// The first overload behaves like a task constructor that takes a single parameter.
/// <para>The second overload associates the cancellation token provided with the newly created task. If you use this overload you are not
/// allowed to pass in a different <c>task</c> object as the first parameter.</para>
/// <para>The type of the returned task is inferred from the first parameter to the function. If <paramref name="_Param"/> is a <c>task_completion_event&lt;T&gt;</c>,
/// a <c>task&lt;T&gt;</c>, or a functor that returns either type <c>T</c> or <c>task&lt;T&gt;</c>, the type of the created task is <c>task&lt;T&gt;</c>.</para>
/// <para>In a Windows Store app, if <paramref name="_Param"/> is of type Windows::Foundation::IAsyncOperation&lt;T&gt;^ or
/// Windows::Foundation::IAsyncOperationWithProgress&lt;T,P&gt;^, or a functor that returns either of those types, the created task will be of type <c>task&lt;T&gt;</c>.
/// If <paramref name="_Param"/> is of type Windows::Foundation::IAsyncAction^ or Windows::Foundation::IAsyncActionWithProgress&lt;P&gt;^, or a functor
/// that returns either of those types, the created task will have type <c>task&lt;void&gt;</c>.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
__declspec(noinline)
task<_ReturnType> create_task(const task<_ReturnType>& _Task)
{
task<_ReturnType> _CreatedTask(_Task);
return _CreatedTask;
}
#if defined (__cplusplus_winrt)
namespace details
{
template<typename _T>
task<_T> _To_task_helper(Windows::Foundation::IAsyncOperation<_T>^ op)
{
return task<_T>(op);
}
template<typename _T, typename _Progress>
task<_T> _To_task_helper(Windows::Foundation::IAsyncOperationWithProgress<_T, _Progress>^ op)
{
return task<_T>(op);
}
inline task<void> _To_task_helper(Windows::Foundation::IAsyncAction^ op)
{
return task<void>(op);
}
template<typename _Progress>
task<void> _To_task_helper(Windows::Foundation::IAsyncActionWithProgress<_Progress>^ op)
{
return task<void>(op);
}
template<typename _ProgressType>
class _ProgressDispatcherBase
{
public:
virtual ~_ProgressDispatcherBase()
{
}
virtual void _Report(const _ProgressType& _Val) = 0;
};
template<typename _ProgressType, typename _ClassPtrType>
class _ProgressDispatcher : public _ProgressDispatcherBase<_ProgressType>
{
public:
virtual ~_ProgressDispatcher()
{
}
_ProgressDispatcher(_ClassPtrType _Ptr) : _M_ptr(_Ptr)
{
}
virtual void _Report(const _ProgressType& _Val)
{
_M_ptr->_FireProgress(_Val);
}
private:
_ClassPtrType _M_ptr;
};
class _ProgressReporterCtorArgType{};
} // namespace details
/// <summary>
/// The progress reporter class allows reporting progress notifications of a specific type. Each progress_reporter object is bound
/// to a particular asynchronous action or operation.
/// </summary>
/// <typeparam name="_ProgressType">
/// The payload type of each progress notification reported through the progress reporter.
/// </typeparam>
/// <remarks>
/// This type is only available to Windows Store apps.
/// </remarks>
/// <seealso cref="create_async Function"/>
/**/
template<typename _ProgressType>
class progress_reporter
{
typedef std::shared_ptr<details::_ProgressDispatcherBase<_ProgressType>> _PtrType;
public:
/// <summary>
/// Sends a progress report to the asynchronous action or operation to which this progress reporter is bound.
/// </summary>
/// <param name="_Val">
/// The payload to report through a progress notification.
/// </param>
/**/
void report(const _ProgressType& _Val) const
{
_M_dispatcher->_Report(_Val);
}
template<typename _ClassPtrType>
static progress_reporter _CreateReporter(_ClassPtrType _Ptr)
{
progress_reporter _Reporter;
details::_ProgressDispatcherBase<_ProgressType> *_PDispatcher = new details::_ProgressDispatcher<_ProgressType, _ClassPtrType>(_Ptr);
_Reporter._M_dispatcher = _PtrType(_PDispatcher);
return _Reporter;
}
progress_reporter() {}
private:
progress_reporter(details::_ProgressReporterCtorArgType);
_PtrType _M_dispatcher;
};
namespace details
{
//
// maps internal definitions for AsyncStatus and defines states that are not client visible
//
enum _AsyncStatusInternal
{
_AsyncCreated = -1, // externally invisible
// client visible states (must match AsyncStatus exactly)
_AsyncStarted = 0, // Windows::Foundation::AsyncStatus::Started,
_AsyncCompleted = 1, // Windows::Foundation::AsyncStatus::Completed,
_AsyncCanceled = 2, // Windows::Foundation::AsyncStatus::Canceled,
_AsyncError = 3, // Windows::Foundation::AsyncStatus::Error,
// non-client visible internal states
_AsyncCancelPending,
_AsyncClosed,
_AsyncUndefined
};
//
// designates whether the "GetResults" method returns a single result (after complete fires) or multiple results
// (which are progressively consumable between Start state and before Close is called)
//
enum _AsyncResultType
{
SingleResult = 0x0001,
MultipleResults = 0x0002
};
// ***************************************************************************
// Template type traits and helpers for async production APIs:
//
struct _ZeroArgumentFunctor { };
struct _OneArgumentFunctor { };
struct _TwoArgumentFunctor { };
// ****************************************
// CLASS TYPES:
// ********************
// TWO ARGUMENTS:
// non-void arg:
template<typename _Class, typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg1 _Arg1ClassHelperThunk(_ReturnType (_Class::*)(_Arg1, _Arg2) const);
// non-void arg:
template<typename _Class, typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg2 _Arg2ClassHelperThunk(_ReturnType (_Class::*)(_Arg1, _Arg2) const);
template<typename _Class, typename _ReturnType, typename _Arg1, typename _Arg2>
_ReturnType _ReturnTypeClassHelperThunk(_ReturnType (_Class::*)(_Arg1, _Arg2) const);
template<typename _Class, typename _ReturnType, typename _Arg1, typename _Arg2>
_TwoArgumentFunctor _ArgumentCountHelper(_ReturnType (_Class::*)(_Arg1, _Arg2) const);
// ********************
// ONE ARGUMENT:
// non-void arg:
template<typename _Class, typename _ReturnType, typename _Arg1>
_Arg1 _Arg1ClassHelperThunk(_ReturnType (_Class::*)(_Arg1) const);
// non-void arg:
template<typename _Class, typename _ReturnType, typename _Arg1>
void _Arg2ClassHelperThunk(_ReturnType (_Class::*)(_Arg1) const);
template<typename _Class, typename _ReturnType, typename _Arg1>
_ReturnType _ReturnTypeClassHelperThunk(_ReturnType (_Class::*)(_Arg1) const);
template<typename _Class, typename _ReturnType, typename _Arg1>
_OneArgumentFunctor _ArgumentCountHelper(_ReturnType (_Class::*)(_Arg1) const);
// ********************
// ZERO ARGUMENT:
// void arg:
template<typename _Class, typename _ReturnType>
void _Arg1ClassHelperThunk(_ReturnType (_Class::*)() const);
// void arg:
template<typename _Class, typename _ReturnType>
void _Arg2ClassHelperThunk(_ReturnType (_Class::*)() const);
// void arg:
template<typename _Class, typename _ReturnType>
_ReturnType _ReturnTypeClassHelperThunk(_ReturnType (_Class::*)() const);
template<typename _Class, typename _ReturnType>
_ZeroArgumentFunctor _ArgumentCountHelper(_ReturnType (_Class::*)() const);
// ****************************************
// POINTER TYPES:
// ********************
// TWO ARGUMENTS:
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__cdecl *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg2 _Arg2PFNHelperThunk(_ReturnType(__cdecl *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__cdecl *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_TwoArgumentFunctor _ArgumentCountHelper(_ReturnType(__cdecl *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__stdcall *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg2 _Arg2PFNHelperThunk(_ReturnType(__stdcall *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__stdcall *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_TwoArgumentFunctor _ArgumentCountHelper(_ReturnType(__stdcall *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__fastcall *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg2 _Arg2PFNHelperThunk(_ReturnType(__fastcall *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__fastcall *)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_TwoArgumentFunctor _ArgumentCountHelper(_ReturnType(__fastcall *)(_Arg1, _Arg2));
// ********************
// ONE ARGUMENT:
template<typename _ReturnType, typename _Arg1>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__cdecl *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
void _Arg2PFNHelperThunk(_ReturnType(__cdecl *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__cdecl *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_OneArgumentFunctor _ArgumentCountHelper(_ReturnType(__cdecl *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__stdcall *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
void _Arg2PFNHelperThunk(_ReturnType(__stdcall *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__stdcall *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_OneArgumentFunctor _ArgumentCountHelper(_ReturnType(__stdcall *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__fastcall *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
void _Arg2PFNHelperThunk(_ReturnType(__fastcall *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__fastcall *)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_OneArgumentFunctor _ArgumentCountHelper(_ReturnType(__fastcall *)(_Arg1));
// ********************
// ZERO ARGUMENT:
template<typename _ReturnType>
void _Arg1PFNHelperThunk(_ReturnType(__cdecl *)());
template<typename _ReturnType>
void _Arg2PFNHelperThunk(_ReturnType(__cdecl *)());
template<typename _ReturnType>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__cdecl *)());
template<typename _ReturnType>
_ZeroArgumentFunctor _ArgumentCountHelper(_ReturnType(__cdecl *)());
template<typename _ReturnType>
void _Arg1PFNHelperThunk(_ReturnType(__stdcall *)());
template<typename _ReturnType>
void _Arg2PFNHelperThunk(_ReturnType(__stdcall *)());
template<typename _ReturnType>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__stdcall *)());
template<typename _ReturnType>
_ZeroArgumentFunctor _ArgumentCountHelper(_ReturnType(__stdcall *)());
template<typename _ReturnType>
void _Arg1PFNHelperThunk(_ReturnType(__fastcall *)());
template<typename _ReturnType>
void _Arg2PFNHelperThunk(_ReturnType(__fastcall *)());
template<typename _ReturnType>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__fastcall *)());
template<typename _ReturnType>
_ZeroArgumentFunctor _ArgumentCountHelper(_ReturnType(__fastcall *)());
template<typename _T>
struct _FunctorArguments
{
static const size_t _Count = 0;
};
template<>
struct _FunctorArguments<_OneArgumentFunctor>
{
static const size_t _Count = 1;
};
template<>
struct _FunctorArguments<_TwoArgumentFunctor>
{
static const size_t _Count = 2;
};
template<typename _T>
struct _FunctorTypeTraits
{
typedef decltype(_ArgumentCountHelper(&(_T::operator()))) _ArgumentCountType;
static const size_t _ArgumentCount = _FunctorArguments<_ArgumentCountType>::_Count;
typedef decltype(_ReturnTypeClassHelperThunk(&(_T::operator()))) _ReturnType;
typedef decltype(_Arg1ClassHelperThunk(&(_T::operator()))) _Argument1Type;
typedef decltype(_Arg2ClassHelperThunk(&(_T::operator()))) _Argument2Type;
};
template<typename _T>
struct _FunctorTypeTraits<_T *>
{
typedef decltype(_ArgumentCountHelper(stdx::declval<_T*>())) _ArgumentCountType;
static const size_t _ArgumentCount = _FunctorArguments<_ArgumentCountType>::_Count;
typedef decltype(_ReturnTypePFNHelperThunk(stdx::declval<_T*>())) _ReturnType;
typedef decltype(_Arg1PFNHelperThunk(stdx::declval<_T*>())) _Argument1Type;
typedef decltype(_Arg2PFNHelperThunk(stdx::declval<_T*>())) _Argument2Type;
};
template<typename _T>
struct _ProgressTypeTraits
{
static const bool _TakesProgress = false;
typedef void _ProgressType;
};
template<typename _T>
struct _ProgressTypeTraits<progress_reporter<_T>>
{
static const bool _TakesProgress = true;
typedef typename _T _ProgressType;
};
template<typename _T, size_t count = _FunctorTypeTraits<_T>::_ArgumentCount>
struct _CAFunctorOptions
{
static const bool _TakesProgress = false;
static const bool _TakesToken = false;
typedef void _ProgressType;
};
template<typename _T>
struct _CAFunctorOptions<_T, 1>
{
private:
typedef typename _FunctorTypeTraits<_T>::_Argument1Type _Argument1Type;
public:
static const bool _TakesProgress = _ProgressTypeTraits<_Argument1Type>::_TakesProgress;
static const bool _TakesToken = !_TakesProgress;
typedef typename _ProgressTypeTraits<_Argument1Type>::_ProgressType _ProgressType;
};
template<typename _T>
struct _CAFunctorOptions<_T, 2>
{
private:
typedef typename _FunctorTypeTraits<_T>::_Argument1Type _Argument1Type;
public:
static const bool _TakesProgress = true;
static const bool _TakesToken = true;
typedef typename _ProgressTypeTraits<_Argument1Type>::_ProgressType _ProgressType;
};
ref class _Zip
{
};
// ***************************************************************************
// Async Operation Task Generators
//
//
// Functor returns an IAsyncInfo - result needs to be wrapped in a task:
//
template<typename _AsyncSelector, typename _ReturnType>
struct _SelectorTaskGenerator
{
template<typename _Function>
static task<_ReturnType> _GenerateTask_0(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(_Func(), _taskOptinos);
}
template<typename _Function>
static task<_ReturnType> _GenerateTask_1C(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(_Func(_Cts.get_token()), _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_1P(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(_Func(_Progress), _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_2PC(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(_Func(_Progress, _Cts.get_token()), _taskOptinos);
}
};
template<typename _AsyncSelector>
struct _SelectorTaskGenerator<_AsyncSelector, void>
{
template<typename _Function>
static task<void> _GenerateTask_0(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(_Func(), _taskOptinos);
}
template<typename _Function>
static task<void> _GenerateTask_1C(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(_Func(_Cts.get_token()), _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_1P(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(_Func(_Progress), _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_2PC(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(_Func(_Progress, _Cts.get_token()), _taskOptinos);
}
};
//
// Functor returns a result - it needs to be wrapped in a task:
//
template<typename _ReturnType>
struct _SelectorTaskGenerator<_TypeSelectorNoAsync, _ReturnType>
{
#pragma warning(push)
#pragma warning(disable: 4702)
template<typename _Function>
static task<_ReturnType> _GenerateTask_0(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>( [=]() -> _ReturnType {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
return _Func();
}, _taskOptinos);
}
#pragma warning(pop)
template<typename _Function>
static task<_ReturnType> _GenerateTask_1C(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>( [=]() -> _ReturnType {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
return _Func(_Cts.get_token());
}, _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_1P(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>( [=]() -> _ReturnType {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
return _Func(_Progress);
}, _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_2PC(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>( [=]() -> _ReturnType {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
return _Func(_Progress, _Cts.get_token());
}, _taskOptinos);
}
};
template<>
struct _SelectorTaskGenerator<_TypeSelectorNoAsync, void>
{
template<typename _Function>
static task<void> _GenerateTask_0(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>( [=]() {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
_Func();
}, _taskOptinos);
}
template<typename _Function>
static task<void> _GenerateTask_1C(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>( [=]() {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
_Func(_Cts.get_token());
}, _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_1P(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>( [=]() {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
_Func(_Progress);
}, _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_2PC(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>( [=]() {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
_Func(_Progress, _Cts.get_token());
}, _taskOptinos);
}
};
//
// Functor returns a task - the task can directly be returned:
//
template<typename _ReturnType>
struct _SelectorTaskGenerator<_TypeSelectorAsyncTask, _ReturnType>
{
template<typename _Function>
static task<_ReturnType> _GenerateTask_0(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _Func();
}
template<typename _Function>
static task<_ReturnType> _GenerateTask_1C(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _Func(_Cts.get_token());
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_1P(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _Func(_Progress);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_2PC(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _Func(_Progress, _Cts.get_token());
}
};
template<>
struct _SelectorTaskGenerator<_TypeSelectorAsyncTask, void>
{
template<typename _Function>
static task<void> _GenerateTask_0(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _Func();
}
template<typename _Function>
static task<void> _GenerateTask_1C(const _Function& _Func, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _Func(_Cts.get_token());
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_1P(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _Func(_Progress);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_2PC(const _Function& _Func, const _ProgressObject& _Progress, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _Func(_Progress, _Cts.get_token());
}
};
template<typename _Generator, bool _TakesToken, bool TakesProgress>
struct _TaskGenerator
{
};
template<typename _Generator>
struct _TaskGenerator<_Generator, false, false>
{
template<typename _Function, typename _ClassPtr, typename _ProgressType>
static auto _GenerateTask(const _Function& _Func, _ClassPtr _Ptr, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
-> decltype(_Generator::_GenerateTask_0(_Func, _Cts, _callstack))
{
return _Generator::_GenerateTask_0(_Func, _Cts, _callstack);
}
};
template<typename _Generator>
struct _TaskGenerator<_Generator, true, false>
{
template<typename _Function, typename _ClassPtr, typename _ProgressType>
static auto _GenerateTask(const _Function& _Func, _ClassPtr _Ptr, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
-> decltype(_Generator::_GenerateTask_0(_Func, _Cts, _callstack))
{
return _Generator::_GenerateTask_1C(_Func, _Cts, _callstack);
}
};
template<typename _Generator>
struct _TaskGenerator<_Generator, false, true>
{
template<typename _Function, typename _ClassPtr, typename _ProgressType>
static auto _GenerateTask(const _Function& _Func, _ClassPtr _Ptr, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
-> decltype(_Generator::_GenerateTask_0(_Func, _Cts, _callstack))
{
return _Generator::_GenerateTask_1P(_Func, progress_reporter<_ProgressType>::_CreateReporter(_Ptr), _Cts, _callstack);
}
};
template<typename _Generator>
struct _TaskGenerator<_Generator, true, true>
{
template<typename _Function, typename _ClassPtr, typename _ProgressType>
static auto _GenerateTask(const _Function& _Func, _ClassPtr _Ptr, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
-> decltype(_Generator::_GenerateTask_0(_Func, _Cts, _callstack))
{
return _Generator::_GenerateTask_2PC(_Func, progress_reporter<_ProgressType>::_CreateReporter(_Ptr), _Cts, _callstack);
}
};
// ***************************************************************************
// Async Operation Attributes Classes
//
// These classes are passed through the hierarchy of async base classes in order to hold multiple attributes of a given async construct in
// a single container. An attribute class must define:
//
// Mandatory:
// -------------------------
//
// _AsyncBaseType : The Windows Runtime interface which is being implemented.
// _CompletionDelegateType : The Windows Runtime completion delegate type for the interface.
// _ProgressDelegateType : If _TakesProgress is true, the Windows Runtime progress delegate type for the interface. If it is false, an empty Windows Runtime type.
// _ReturnType : The return type of the async construct (void for actions / non-void for operations)
//
// _TakesProgress : An indication as to whether or not
//
// _Generate_Task : A function adapting the user's function into what's necessary to produce the appropriate task
//
// Optional:
// -------------------------
//
template<typename _Function, typename _ProgressType, typename _ReturnType, typename _TaskTraits, bool _TakesToken, bool _TakesProgress>
struct _AsyncAttributes
{
};
template<typename _Function, typename _ProgressType, typename _ReturnType, typename _TaskTraits, bool _TakesToken>
struct _AsyncAttributes<_Function, _ProgressType, _ReturnType, _TaskTraits, _TakesToken, true>
{
typedef typename Windows::Foundation::IAsyncOperationWithProgress<_ReturnType, _ProgressType> _AsyncBaseType;
typedef typename Windows::Foundation::AsyncOperationProgressHandler<_ReturnType, _ProgressType> _ProgressDelegateType;
typedef typename Windows::Foundation::AsyncOperationWithProgressCompletedHandler<_ReturnType, _ProgressType> _CompletionDelegateType;
typedef typename _ReturnType _ReturnType;
typedef typename _ProgressType _ProgressType;
typedef typename _TaskTraits::_AsyncKind _AsyncKind;
typedef typename _SelectorTaskGenerator<_AsyncKind, _ReturnType> _SelectorTaskGenerator;
typedef typename _TaskGenerator<_SelectorTaskGenerator, _TakesToken, true> _TaskGenerator;
static const bool _TakesProgress = true;
static const bool _TakesToken = _TakesToken;
template<typename _Function, typename _ClassPtr>
static task<_ReturnType> _Generate_Task(const _Function& _Func, _ClassPtr _Ptr, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _TaskGenerator::_GenerateTask<_Function, _ClassPtr, _ProgressType>(_Func, _Ptr, _Cts, _callstack);
}
};
template<typename _Function, typename _ProgressType, typename _ReturnType, typename _TaskTraits, bool _TakesToken>
struct _AsyncAttributes<_Function, _ProgressType, _ReturnType, _TaskTraits, _TakesToken, false>
{
typedef typename Windows::Foundation::IAsyncOperation<_ReturnType> _AsyncBaseType;
typedef _Zip _ProgressDelegateType;
typedef typename Windows::Foundation::AsyncOperationCompletedHandler<_ReturnType> _CompletionDelegateType;
typedef typename _ReturnType _ReturnType;
typedef typename _TaskTraits::_AsyncKind _AsyncKind;
typedef typename _SelectorTaskGenerator<_AsyncKind, _ReturnType> _SelectorTaskGenerator;
typedef typename _TaskGenerator<_SelectorTaskGenerator, _TakesToken, false> _TaskGenerator;
static const bool _TakesProgress = false;
static const bool _TakesToken = _TakesToken;
template<typename _Function, typename _ClassPtr>
static task<_ReturnType> _Generate_Task(const _Function& _Func, _ClassPtr _Ptr, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _TaskGenerator::_GenerateTask<_Function, _ClassPtr, _ProgressType>(_Func, _Ptr, _Cts, _callstack);
}
};
template<typename _Function, typename _ProgressType, typename _TaskTraits, bool _TakesToken>
struct _AsyncAttributes<_Function, _ProgressType, void, _TaskTraits, _TakesToken, true>
{
typedef typename Windows::Foundation::IAsyncActionWithProgress<_ProgressType> _AsyncBaseType;
typedef typename Windows::Foundation::AsyncActionProgressHandler<_ProgressType> _ProgressDelegateType;
typedef typename Windows::Foundation::AsyncActionWithProgressCompletedHandler<_ProgressType> _CompletionDelegateType;
typedef void _ReturnType;
typedef typename _ProgressType _ProgressType;
typedef typename _TaskTraits::_AsyncKind _AsyncKind;
typedef typename _SelectorTaskGenerator<_AsyncKind, _ReturnType> _SelectorTaskGenerator;
typedef typename _TaskGenerator<_SelectorTaskGenerator, _TakesToken, true> _TaskGenerator;
static const bool _TakesProgress = true;
static const bool _TakesToken = _TakesToken;
template<typename _Function, typename _ClassPtr>
static task<_ReturnType> _Generate_Task(const _Function& _Func, _ClassPtr _Ptr, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _TaskGenerator::_GenerateTask<_Function, _ClassPtr, _ProgressType>(_Func, _Ptr, _Cts, _callstack);
}
};
template<typename _Function, typename _ProgressType, typename _TaskTraits, bool _TakesToken>
struct _AsyncAttributes<_Function, _ProgressType, void, _TaskTraits, _TakesToken, false>
{
typedef typename Windows::Foundation::IAsyncAction _AsyncBaseType;
typedef _Zip _ProgressDelegateType;
typedef typename Windows::Foundation::AsyncActionCompletedHandler _CompletionDelegateType;
typedef void _ReturnType;
typedef typename _TaskTraits::_AsyncKind _AsyncKind;
typedef typename _SelectorTaskGenerator<_AsyncKind, _ReturnType> _SelectorTaskGenerator;
typedef typename _TaskGenerator<_SelectorTaskGenerator, _TakesToken, false> _TaskGenerator;
static const bool _TakesProgress = false;
static const bool _TakesToken = _TakesToken;
template<typename _Function, typename _ClassPtr>
static task<_ReturnType> _Generate_Task(const _Function& _Func, _ClassPtr _Ptr, cancellation_token_source _Cts, const _TaskCreationCallstack & _callstack)
{
return _TaskGenerator::_GenerateTask<_Function, _ClassPtr, _ProgressType>(_Func, _Ptr, _Cts, _callstack);
}
};
template<typename _Function>
struct _AsyncLambdaTypeTraits
{
typedef typename _FunctorTypeTraits<_Function>::_ReturnType _ReturnType;
typedef typename _FunctorTypeTraits<_Function>::_Argument1Type _Argument1Type;
typedef typename _CAFunctorOptions<_Function>::_ProgressType _ProgressType;
static const bool _TakesProgress = _CAFunctorOptions<_Function>::_TakesProgress;
static const bool _TakesToken = _CAFunctorOptions<_Function>::_TakesToken;
typedef typename _TaskTypeTraits<_ReturnType> _TaskTraits;
typedef typename _AsyncAttributes<_Function, _ProgressType, typename _TaskTraits::_TaskRetType, _TaskTraits, _TakesToken, _TakesProgress> _AsyncAttributes;
};
// ***************************************************************************
// AsyncInfo (and completion) Layer:
//
//
// Internal base class implementation for async operations (based on internal Windows representation for ABI level async operations)
//
template < typename _Attributes, _AsyncResultType resultType = SingleResult >
ref class _AsyncInfoBase abstract : _Attributes::_AsyncBaseType
{
internal:
_AsyncInfoBase() :
_M_currentStatus(_AsyncStatusInternal::_AsyncCreated),
_M_errorCode(S_OK),
_M_completeDelegate(nullptr),
_M_CompleteDelegateAssigned(0),
_M_CallbackMade(0)
{
_M_id = ::Concurrency::details::platform::GetNextAsyncId();
}
public:
virtual typename _Attributes::_ReturnType GetResults()
{
throw ::Platform::Exception::CreateException(E_UNEXPECTED);
}
virtual property unsigned int Id
{
unsigned int get()
{
_CheckValidStateForAsyncInfoCall();
return _M_id;
}
void set(unsigned int id)
{
_CheckValidStateForAsyncInfoCall();
if (id == 0)
{
throw ::Platform::Exception::CreateException(E_INVALIDARG);
}
else if (_M_currentStatus != _AsyncStatusInternal::_AsyncCreated)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
_M_id = id;
}
}
virtual property Windows::Foundation::AsyncStatus Status
{
Windows::Foundation::AsyncStatus get()
{
_CheckValidStateForAsyncInfoCall();
_AsyncStatusInternal _Current = _M_currentStatus;
//
// Map our internal cancel pending to cancelled. This way "pending cancelled" looks to the outside as "cancelled" but
// can still transition to "completed" if the operation completes without acknowledging the cancellation request
//
switch(_Current)
{
case _AsyncCancelPending:
_Current = _AsyncCanceled;
break;
case _AsyncCreated:
_Current = _AsyncStarted;
break;
default:
break;
}
return static_cast<Windows::Foundation::AsyncStatus>(_Current);
}
}
virtual property Windows::Foundation::HResult ErrorCode
{
Windows::Foundation::HResult get()
{
_CheckValidStateForAsyncInfoCall();
Windows::Foundation::HResult _Hr;
_Hr.Value = _M_errorCode;
return _Hr;
}
}
virtual property typename _Attributes::_ProgressDelegateType^ Progress
{
typename typename _Attributes::_ProgressDelegateType^ get()
{
return _GetOnProgress();
}
void set(typename _Attributes::_ProgressDelegateType^ _ProgressHandler)
{
_PutOnProgress(_ProgressHandler);
}
}
virtual void Cancel()
{
if (_TransitionToState(_AsyncCancelPending))
{
_OnCancel();
}
}
virtual void Close()
{
if (_TransitionToState(_AsyncClosed))
{
_OnClose();
}
else
{
if (_M_currentStatus != _AsyncClosed) // Closed => Closed transition is just ignored
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_STATE_CHANGE);
}
}
}
virtual property typename _Attributes::_CompletionDelegateType^ Completed
{
typename _Attributes::_CompletionDelegateType^ get()
{
_CheckValidStateForDelegateCall();
return _M_completeDelegate;
}
void set(typename _Attributes::_CompletionDelegateType^ _CompleteHandler)
{
_CheckValidStateForDelegateCall();
// this delegate property is "write once"
if (InterlockedIncrement(&_M_CompleteDelegateAssigned) == 1)
{
_M_completeDelegateContext = _ContextCallback::_CaptureCurrent();
_M_completeDelegate = _CompleteHandler;
// Guarantee that the write of _M_completeDelegate is ordered with respect to the read of state below
// as perceived from _FireCompletion on another thread.
MemoryBarrier();
if (_IsTerminalState())
{
_FireCompletion();
}
}
else
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_DELEGATE_ASSIGNMENT);
}
}
}
protected private:
// _Start - this is not externally visible since async operations "hot start" before returning to the caller
void _Start()
{
if (_TransitionToState(_AsyncStarted))
{
_OnStart();
}
else
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_STATE_CHANGE);
}
}
void _FireCompletion()
{
_TryTransitionToCompleted();
// we guarantee that completion can only ever be fired once
if (_M_completeDelegate != nullptr && InterlockedIncrement(&_M_CallbackMade) == 1)
{
_M_completeDelegateContext._CallInContext([=] {
_M_completeDelegate((_Attributes::_AsyncBaseType^)this, this->Status);
_M_completeDelegate = nullptr;
});
}
}
virtual typename _Attributes::_ProgressDelegateType^ _GetOnProgress()
{
throw ::Platform::Exception::CreateException(E_UNEXPECTED);
}
virtual void _PutOnProgress(typename _Attributes::_ProgressDelegateType^ _ProgressHandler)
{
throw ::Platform::Exception::CreateException(E_UNEXPECTED);
}
bool _TryTransitionToCompleted()
{
return _TransitionToState(_AsyncStatusInternal::_AsyncCompleted);
}
bool _TryTransitionToCancelled()
{
return _TransitionToState(_AsyncStatusInternal::_AsyncCanceled);
}
bool _TryTransitionToError(const HRESULT error)
{
_InterlockedCompareExchange(reinterpret_cast<volatile LONG*>(&_M_errorCode), error, S_OK);
return _TransitionToState(_AsyncStatusInternal::_AsyncError);
}
// This method checks to see if the delegate properties can be
// modified in the current state and generates the appropriate
// error hr in the case of violation.
inline void _CheckValidStateForDelegateCall()
{
if (_M_currentStatus == _AsyncClosed)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
}
// This method checks to see if results can be collected in the
// current state and generates the appropriate error hr in
// the case of a violation.
inline void _CheckValidStateForResultsCall()
{
_AsyncStatusInternal _Current = _M_currentStatus;
if (_Current == _AsyncError)
{
throw ::Platform::Exception::CreateException(_M_errorCode);
}
#pragma warning(push)
#pragma warning(disable: 4127) // Conditional expression is constant
// single result illegal before transition to Completed or Cancelled state
if (resultType == SingleResult)
#pragma warning(pop)
{
if (_Current != _AsyncCompleted)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
}
// multiple results can be called after Start has been called and before/after Completed
else if (_Current != _AsyncStarted &&
_Current != _AsyncCancelPending &&
_Current != _AsyncCanceled &&
_Current != _AsyncCompleted)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
}
// This method can be called by derived classes periodically to determine
// whether the asynchronous operation should continue processing or should
// be halted.
inline bool _ContinueAsyncOperation()
{
return (_M_currentStatus == _AsyncStarted);
}
// These two methods are used to allow the async worker implementation do work on
// state transitions. No real "work" should be done in these methods. In other words
// they should not block for a long time on UI timescales.
virtual void _OnStart() = 0;
virtual void _OnClose() = 0;
virtual void _OnCancel() = 0;
private:
// This method is used to check if calls to the AsyncInfo properties
// (id, status, errorcode) are legal in the current state. It also
// generates the appropriate error hr to return in the case of an
// illegal call.
inline void _CheckValidStateForAsyncInfoCall()
{
_AsyncStatusInternal _Current = _M_currentStatus;
if (_Current == _AsyncClosed)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
else if (_Current == _AsyncCreated)
{
throw ::Platform::Exception::CreateException(E_ASYNC_OPERATION_NOT_STARTED);
}
}
inline bool _TransitionToState(const _AsyncStatusInternal _NewState)
{
_AsyncStatusInternal _Current = _M_currentStatus;
// This enforces the valid state transitions of the asynchronous worker object
// state machine.
switch(_NewState)
{
case _AsyncStatusInternal::_AsyncStarted:
if (_Current != _AsyncCreated)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncCompleted:
if (_Current != _AsyncStarted && _Current != _AsyncCancelPending)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncCancelPending:
if (_Current != _AsyncStarted)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncCanceled:
if (_Current != _AsyncStarted && _Current != _AsyncCancelPending)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncError:
if (_Current != _AsyncStarted && _Current != _AsyncCancelPending)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncClosed:
if (!_IsTerminalState(_Current))
{
return false;
}
break;
default:
return false;
break;
}
// attempt the transition to the new state
// Note: if currentStatus_ == _Current, then there was no intervening write
// by the async work object and the swap succeeded.
_AsyncStatusInternal _RetState = static_cast<_AsyncStatusInternal>(
_InterlockedCompareExchange(reinterpret_cast<volatile LONG*>(&_M_currentStatus),
_NewState,
static_cast<LONG>(_Current)));
// ICE returns the former state, if the returned state and the
// state we captured at the beginning of this method are the same,
// the swap succeeded.
return (_RetState == _Current);
}
inline bool _IsTerminalState()
{
return _IsTerminalState(_M_currentStatus);
}
inline bool _IsTerminalState(_AsyncStatusInternal status)
{
return (status == _AsyncError ||
status == _AsyncCanceled ||
status == _AsyncCompleted ||
status == _AsyncClosed);
}
private:
_ContextCallback _M_completeDelegateContext;
typename _Attributes::_CompletionDelegateType^ volatile _M_completeDelegate;
_AsyncStatusInternal volatile _M_currentStatus;
HRESULT volatile _M_errorCode;
unsigned int _M_id;
long volatile _M_CompleteDelegateAssigned;
long volatile _M_CallbackMade;
};
// ***************************************************************************
// Progress Layer (optional):
//
template< typename _Attributes, bool _HasProgress, _AsyncResultType _ResultType = SingleResult >
ref class _AsyncProgressBase abstract : _AsyncInfoBase<_Attributes, _ResultType>
{
};
template< typename _Attributes, _AsyncResultType _ResultType>
ref class _AsyncProgressBase<_Attributes, true, _ResultType> abstract : _AsyncInfoBase<_Attributes, _ResultType>
{
internal:
_AsyncProgressBase() : _AsyncInfoBase<_Attributes, _ResultType>(),
_M_progressDelegate(nullptr)
{
}
virtual typename _Attributes::_ProgressDelegateType^ _GetOnProgress() override
{
_CheckValidStateForDelegateCall();
return _M_progressDelegate;
}
virtual void _PutOnProgress(typename _Attributes::_ProgressDelegateType^ _ProgressHandler) override
{
_CheckValidStateForDelegateCall();
_M_progressDelegate = _ProgressHandler;
_M_progressDelegateContext = _ContextCallback::_CaptureCurrent();
}
void _FireProgress(const typename _Attributes::_ProgressType& _ProgressValue)
{
if (_M_progressDelegate != nullptr)
{
_M_progressDelegateContext._CallInContext([=] {
_M_progressDelegate((_Attributes::_AsyncBaseType^)this, _ProgressValue);
});
}
}
private:
_ContextCallback _M_progressDelegateContext;
typename _Attributes::_ProgressDelegateType^ _M_progressDelegate;
};
template<typename _Attributes, _AsyncResultType _ResultType = SingleResult>
ref class _AsyncBaseProgressLayer abstract : _AsyncProgressBase<_Attributes, _Attributes::_TakesProgress, _ResultType>
{
};
// ***************************************************************************
// Task Adaptation Layer:
//
//
// _AsyncTaskThunkBase provides a bridge between IAsync<Action/Operation> and task.
//
template<typename _Attributes, typename _ReturnType>
ref class _AsyncTaskThunkBase abstract : _AsyncBaseProgressLayer<_Attributes>
{
public:
virtual _ReturnType GetResults() override
{
_CheckValidStateForResultsCall();
return _M_task.get();
}
internal:
typedef task<_ReturnType> _TaskType;
_AsyncTaskThunkBase(const _TaskType& _Task)
: _M_task(_Task)
{
}
_AsyncTaskThunkBase()
{
}
protected:
virtual void _OnStart() override
{
_M_task.then( [=](_TaskType _Antecedent) {
try
{
_Antecedent.get();
}
catch(task_canceled&)
{
_TryTransitionToCancelled();
}
catch(::Platform::Exception^ _Ex)
{
_TryTransitionToError(_Ex->HResult);
}
catch(...)
{
_TryTransitionToError(E_FAIL);
}
_FireCompletion();
});
}
internal:
_TaskType _M_task;
cancellation_token_source _M_cts;
};
template<typename _Attributes>
ref class _AsyncTaskThunk : _AsyncTaskThunkBase<_Attributes, typename _Attributes::_ReturnType>
{
internal:
_AsyncTaskThunk(const _TaskType& _Task) :
_AsyncTaskThunkBase(_Task)
{
}
_AsyncTaskThunk()
{
}
protected:
virtual void _OnClose() override
{
}
virtual void _OnCancel() override
{
_M_cts.cancel();
}
};
// ***************************************************************************
// Async Creation Layer:
//
template<typename _Function>
ref class _AsyncTaskGeneratorThunk sealed : _AsyncTaskThunk<typename _AsyncLambdaTypeTraits<_Function>::_AsyncAttributes>
{
internal:
typedef typename _AsyncLambdaTypeTraits<_Function>::_AsyncAttributes _Attributes;
typedef typename _AsyncTaskThunk<_Attributes> _Base;
typedef typename _Attributes::_AsyncBaseType _AsyncBaseType;
_AsyncTaskGeneratorThunk(const _Function& _Func, const _TaskCreationCallstack &_callstack) : _M_func(_Func), _M_creationCallstack(_callstack)
{
// Virtual call here is safe as the class is declared 'sealed'
_Start();
}
protected:
//
// The only thing we must do different from the base class is we must spin the hot task on transition from Created->Started. Otherwise,
// let the base thunk handle everything.
//
virtual void _OnStart() override
{
//
// Call the appropriate task generator to actually produce a task of the expected type. This might adapt the user lambda for progress reports,
// wrap the return result in a task, or allow for direct return of a task depending on the form of the lambda.
//
_M_task = _Attributes::_Generate_Task(_M_func, this, _M_cts, _M_creationCallstack);
_Base::_OnStart();
}
virtual void _OnCancel() override
{
_Base::_OnCancel();
}
private:
_TaskCreationCallstack _M_creationCallstack;
_Function _M_func;
};
} // namespace details
/// <summary>
/// Creates a Windows Runtime asynchronous construct based on a user supplied lambda or function object. The return type of <c>create_async</c> is
/// one of either <c>IAsyncAction^</c>, <c>IAsyncActionWithProgress&lt;TProgress&gt;^</c>, <c>IAsyncOperation&lt;TResult&gt;^</c>, or
/// <c>IAsyncOperationWithProgress&lt;TResult, TProgress&gt;^</c> based on the signature of the lambda passed to the method.
/// </summary>
/// <param name="_Func">
/// The lambda or function object from which to create a Windows Runtime asynchronous construct.
/// </param>
/// <returns>
/// An asynchronous construct represented by an IAsyncAction^, IAsyncActionWithProgress&lt;TProgress&gt;^, IAsyncOperation&lt;TResult&gt;^, or an
/// IAsyncOperationWithProgress&lt;TResult, TProgress&gt;^. The interface returned depends on the signature of the lambda passed into the function.
/// </returns>
/// <remarks>
/// The return type of the lambda determines whether the construct is an action or an operation.
/// <para>Lambdas that return void cause the creation of actions. Lambdas that return a result of type <c>TResult</c> cause the creation of
/// operations of TResult.</para>
/// <para>The lambda may also return a <c>task&lt;TResult&gt;</c> which encapsulates the aysnchronous work within itself or is the continuation of
/// a chain of tasks that represent the asynchronous work. In this case, the lambda itself is executed inline, since the tasks are the ones that
/// execute asynchronously, and the return type of the lambda is unwrapped to produce the asynchronous construct returned by <c>create_async</c>.
/// This implies that a lambda that returns a task&lt;void&gt; will cause the creation of actions, and a lambda that returns a task&lt;TResult&gt; will
/// cause the creation of operations of TResult.</para>
/// <para>The lambda may take either zero, one or two arguments. The valid arguments are <c>progress_reporter&lt;TProgress&gt;</c> and
/// <c>cancellation_token</c>, in that order if both are used. A lambda without arguments causes the creation of an asynchronous construct without
/// the capability for progress reporting. A lambda that takes a progress_reporter&lt;TProgress&gt; will cause <c>create_async</c> to return an asynchronous
/// construct which reports progress of type TProgress each time the <c>report</c> method of the progress_reporter object is called. A lambda that
/// takes a cancellation_token may use that token to check for cancellation, or pass it to tasks that it creates so that cancellation of the
/// asynchronous construct causes cancellation of those tasks.</para>
/// <para>If the body of the lambda or function object returns a result (and not a task&lt;TResult&gt;), the lamdba will be executed
/// asynchronously within the process MTA in the context of a task the Runtime implicitly creates for it. The <c>IAsyncInfo::Cancel</c> method will
/// cause cancellation of the implicit task.</para>
/// <para>If the body of the lambda returns a task, the lamba executes inline, and by declaring the lambda to take an argument of type
/// <c>cancellation_token</c> you can trigger cancellation of any tasks you create within the lambda by passing that token in when you create them.
/// You may also use the <c>register_callback</c> method on the token to cause the Runtime to invoke a callback when you call <c>IAsyncInfo::Cancel</c> on
/// the async operation or action produced..</para>
/// <para>This function is only available to Windows Store apps.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/// <seealso cref="progress_reporter Class"/>
/// <seealso cref="cancelation_token Class"/>
/**/
template<typename _Function>
__declspec(noinline)
details::_AsyncTaskGeneratorThunk<_Function> ^create_async(const _Function& _Func)
{
static_assert(std::is_same<decltype(details::_IsValidCreateAsync(_Func,0,0,0,0)),std::true_type>::value,
"argument to create_async must be a callable object taking zero, one or two arguments");
return ref new details::_AsyncTaskGeneratorThunk<_Function>(_Func, _CAPTURE_CALLSTACK());
}
#endif /* defined (__cplusplus_winrt) */
namespace details
{
// Helper struct for when_all operators to know when tasks have completed
template<typename _Type>
struct _RunAllParam
{
_RunAllParam() : _M_completeCount(0), _M_numTasks(0)
{
}
void _Resize(size_t _Len, bool _SkipVector = false)
{
_M_numTasks = _Len;
if (!_SkipVector)
{
_M_vector._Result.resize(_Len);
}
}
task_completion_event<_Unit_type> _M_completed;
_ResultHolder<std::vector<_Type> > _M_vector;
_ResultHolder<_Type> _M_mergeVal;
atomic_size_t _M_completeCount;
size_t _M_numTasks;
};
template<typename _Type>
struct _RunAllParam<std::vector<_Type> >
{
_RunAllParam() : _M_completeCount(0), _M_numTasks(0)
{
}
void _Resize(size_t _Len, bool _SkipVector = false)
{
_M_numTasks = _Len;
if (!_SkipVector)
{
_M_vector.resize(_Len);
}
}
task_completion_event<_Unit_type> _M_completed;
std::vector<_ResultHolder<std::vector<_Type> > > _M_vector;
atomic_size_t _M_completeCount;
size_t _M_numTasks;
};
// Helper struct specialization for void
template<>
struct _RunAllParam<_Unit_type>
{
_RunAllParam() : _M_completeCount(0), _M_numTasks(0)
{
}
void _Resize(size_t _Len)
{
_M_numTasks = _Len;
}
task_completion_event<_Unit_type> _M_completed;
atomic_size_t _M_completeCount;
size_t _M_numTasks;
};
inline void _JoinAllTokens_Add(const cancellation_token_source& _MergedSrc, _CancellationTokenState *_PJoinedTokenState)
{
if (_PJoinedTokenState != nullptr && _PJoinedTokenState != _CancellationTokenState::_None())
{
cancellation_token _T = cancellation_token::_FromImpl(_PJoinedTokenState);
_T.register_callback( [=](){
_MergedSrc.cancel();
});
}
}
template<typename _ElementType, typename _Function, typename _TaskType>
void _WhenAllContinuationWrapper(_RunAllParam<_ElementType>* _PParam, _Function _Func, task<_TaskType>& _Task)
{
if (_Task._GetImpl()->_IsCompleted())
{
_Func();
if (atomic_increment(_PParam->_M_completeCount) == _PParam->_M_numTasks)
{
// Inline execute its direct continuation, the _ReturnTask
_PParam->_M_completed.set(_Unit_type());
// It's safe to delete it since all usage of _PParam in _ReturnTask has been finished.
delete _PParam;
}
}
else
{
_ASSERTE(_Task._GetImpl()->_IsCanceled());
if (_Task._GetImpl()->_HasUserException())
{
// _Cancel will return false if the TCE is already canceled with or without exception
_PParam->_M_completed._Cancel(_Task._GetImpl()->_GetExceptionHolder());
}
else
{
_PParam->_M_completed._Cancel();
}
if (atomic_increment(_PParam->_M_completeCount) == _PParam->_M_numTasks)
{
delete _PParam;
}
}
}
template<typename _ElementType, typename _Iterator>
struct _WhenAllImpl
{
static task<std::vector<_ElementType>> _Perform(const task_options& _TaskOptions, _Iterator _Begin, _Iterator _End)
{
_CancellationTokenState *_PTokenState = _TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAllParam<_ElementType>();
cancellation_token_source _MergedSource;
// Step1: Create task completion event.
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_MergedSource.get_token());
task<_Unit_type> _All_tasks_completed(_PParam->_M_completed, _Options);
// The return task must be created before step 3 to enforce inline execution.
auto _ReturnTask = _All_tasks_completed._Then([=](_Unit_type) -> std::vector<_ElementType> {
return _PParam->_M_vector.Get();
}, nullptr);
// Step2: Combine and check tokens, and count elements in range.
if (_PTokenState)
{
_JoinAllTokens_Add(_MergedSource, _PTokenState);
_PParam->_Resize(static_cast<size_t>(std::distance(_Begin, _End)));
}
else
{
size_t _TaskNum = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
_TaskNum++;
_JoinAllTokens_Add(_MergedSource, _PTask->_GetImpl()->_M_pTokenState);
}
_PParam->_Resize(_TaskNum);
}
// Step3: Check states of previous tasks.
if( _Begin == _End )
{
_PParam->_M_completed.set(_Unit_type());
delete _PParam;
}
else
{
size_t _Index = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PTask->_Then([_PParam, _Index](task<_ElementType> _ResultTask) {
// Dev10 compiler bug
typedef _ElementType _ElementTypeDev10;
auto _PParamCopy = _PParam;
auto _IndexCopy = _Index;
auto _Func = [_PParamCopy, _IndexCopy, &_ResultTask](){
_PParamCopy->_M_vector._Result[_IndexCopy] = _ResultTask._GetImpl()->_GetResult();
};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
}, _CancellationTokenState::_None());
_Index++;
}
}
return _ReturnTask;
}
};
template<typename _ElementType, typename _Iterator>
struct _WhenAllImpl<std::vector<_ElementType>, _Iterator>
{
static task<std::vector<_ElementType>> _Perform(const task_options& _TaskOptions, _Iterator _Begin, _Iterator _End)
{
_CancellationTokenState *_PTokenState = _TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAllParam<std::vector<_ElementType>>();
cancellation_token_source _MergedSource;
// Step1: Create task completion event.
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_MergedSource.get_token());
task<_Unit_type> _All_tasks_completed(_PParam->_M_completed, _Options);
// The return task must be created before step 3 to enforce inline execution.
auto _ReturnTask = _All_tasks_completed._Then([=](_Unit_type) -> std::vector<_ElementType> {
_ASSERTE(_PParam->_M_completeCount == _PParam->_M_numTasks);
std::vector<_ElementType> _Result;
for(size_t _I = 0; _I < _PParam->_M_numTasks; _I++)
{
const std::vector<_ElementType>& _Vec = _PParam->_M_vector[_I].Get();
_Result.insert(_Result.end(), _Vec.begin(), _Vec.end());
}
return _Result;
}, nullptr);
// Step2: Combine and check tokens, and count elements in range.
if (_PTokenState)
{
_JoinAllTokens_Add(_MergedSource, _PTokenState);
_PParam->_Resize(static_cast<size_t>(std::distance(_Begin, _End)));
}
else
{
size_t _TaskNum = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
_TaskNum++;
_JoinAllTokens_Add(_MergedSource, _PTask->_GetImpl()->_M_pTokenState);
}
_PParam->_Resize(_TaskNum);
}
// Step3: Check states of previous tasks.
if( _Begin == _End )
{
_PParam->_M_completed.set(_Unit_type());
delete _PParam;
}
else
{
size_t _Index = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PTask->_Then([_PParam, _Index](task<std::vector<_ElementType>> _ResultTask) {
// Dev10 compiler bug
typedef _ElementType _ElementTypeDev10;
auto _PParamCopy = _PParam;
auto _IndexCopy = _Index;
auto _Func = [_PParamCopy, _IndexCopy, &_ResultTask]() {
_PParamCopy->_M_vector[_IndexCopy].Set(_ResultTask._GetImpl()->_GetResult());
};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
}, _CancellationTokenState::_None());
_Index++;
}
}
return _ReturnTask;
}
};
template<typename _Iterator>
struct _WhenAllImpl<void, _Iterator>
{
static task<void> _Perform(const task_options& _TaskOptions, _Iterator _Begin, _Iterator _End)
{
_CancellationTokenState *_PTokenState = _TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAllParam<_Unit_type>();
cancellation_token_source _MergedSource;
// Step1: Create task completion event.
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_MergedSource.get_token());
task<_Unit_type> _All_tasks_completed(_PParam->_M_completed, _Options);
// The return task must be created before step 3 to enforce inline execution.
auto _ReturnTask = _All_tasks_completed._Then([=](_Unit_type) {
}, nullptr);
// Step2: Combine and check tokens, and count elements in range.
if (_PTokenState)
{
_JoinAllTokens_Add(_MergedSource, _PTokenState);
_PParam->_Resize(static_cast<size_t>(std::distance(_Begin, _End)));
}
else
{
size_t _TaskNum = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
_TaskNum++;
_JoinAllTokens_Add(_MergedSource, _PTask->_GetImpl()->_M_pTokenState);
}
_PParam->_Resize(_TaskNum);
}
// Step3: Check states of previous tasks.
if( _Begin == _End )
{
_PParam->_M_completed.set(_Unit_type());
delete _PParam;
}
else
{
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PTask->_Then([_PParam](task<void> _ResultTask) {
auto _Func = [](){};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
}, _CancellationTokenState::_None());
}
}
return _ReturnTask;
}
};
template<typename _ReturnType>
task<std::vector<_ReturnType>> _WhenAllVectorAndValue(const task<std::vector<_ReturnType>>& _VectorTask, const task<_ReturnType>& _ValueTask,
bool _OutputVectorFirst)
{
auto _PParam = new _RunAllParam<_ReturnType>();
cancellation_token_source _MergedSource;
// Step1: Create task completion event.
task<_Unit_type> _All_tasks_completed(_PParam->_M_completed, _MergedSource.get_token());
// The return task must be created before step 3 to enforce inline execution.
auto _ReturnTask = _All_tasks_completed._Then([=](_Unit_type) -> std::vector<_ReturnType> {
_ASSERTE(_PParam->_M_completeCount == 2);
auto _Result = _PParam->_M_vector.Get(); // copy by value
auto _mergeVal = _PParam->_M_mergeVal.Get();
if (_OutputVectorFirst == true)
{
_Result.push_back(_mergeVal);
}
else
{
_Result.insert(_Result.begin(), _mergeVal);
}
return _Result;
}, nullptr);
// Step2: Combine and check tokens.
_JoinAllTokens_Add(_MergedSource, _VectorTask._GetImpl()->_M_pTokenState);
_JoinAllTokens_Add(_MergedSource, _ValueTask._GetImpl()->_M_pTokenState);
// Step3: Check states of previous tasks.
_PParam->_Resize(2, true);
if (_VectorTask.is_apartment_aware() || _ValueTask.is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_VectorTask._Then([_PParam](task<std::vector<_ReturnType>> _ResultTask) {
// Dev10 compiler bug
typedef _ReturnType _ReturnTypeDev10;
auto _PParamCopy = _PParam;
auto _Func = [_PParamCopy, &_ResultTask]() {
auto _ResultLocal = _ResultTask._GetImpl()->_GetResult();
_PParamCopy->_M_vector.Set(_ResultLocal);
};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
}, _CancellationTokenState::_None());
_ValueTask._Then([_PParam](task<_ReturnType> _ResultTask) {
// Dev10 compiler bug
typedef _ReturnType _ReturnTypeDev10;
auto _PParamCopy = _PParam;
auto _Func = [_PParamCopy, &_ResultTask]() {
auto _ResultLocal = _ResultTask._GetImpl()->_GetResult();
_PParamCopy->_M_mergeVal.Set(_ResultLocal);
};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
}, _CancellationTokenState::_None());
return _ReturnTask;
}
} // namespace details
/// <summary>
/// Creates a task that will complete successfully when all of the tasks supplied as arguments complete successfully.
/// </summary>
/// <typeparam name="_Iterator">
/// The type of the input iterator.
/// </typeparam>
/// <param name="_Begin">
/// The position of the first element in the range of elements to be combined into the resulting task.
/// </param>
/// <param name="_End">
/// The position of the first element beyond the range of elements to be combined into the resulting task.
/// </param>
/// <returns>
/// A task that completes sucessfully when all of the input tasks have completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;&gt;</c>. If the input tasks are of type <c>void</c> the output
/// task will also be a <c>task&lt;void&gt;</c>.
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled state, and the exception,
/// if one is encoutered, will be thrown if you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template <typename _Iterator>
auto when_all(_Iterator _Begin, _Iterator _End, const task_options& _TaskOptions = task_options())
-> decltype (details::_WhenAllImpl<typename std::iterator_traits<_Iterator>::value_type::result_type, _Iterator>::_Perform(_TaskOptions, _Begin, _End))
{
typedef typename std::iterator_traits<_Iterator>::value_type::result_type _ElementType;
return details::_WhenAllImpl<_ElementType, _Iterator>::_Perform(_TaskOptions, _Begin, _End);
}
/// <summary>
/// Creates a task that will complete succesfully when both of the tasks supplied as arguments complete successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when both of the input tasks have completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;&gt;</c>. If the input tasks are of type <c>void</c> the output
/// task will also be a <c>task&lt;void&gt;</c>.
/// <para> To allow for a construct of the sort taskA &amp;&amp; taskB &amp;&amp; taskC, which are combined in pairs, the &amp;&amp; operator
/// produces a <c>task&lt;std::vector&lt;T&gt;&gt;</c> if either one or both of the tasks are of type <c>task&lt;std::vector&lt;T&gt;&gt;</c>.</para>
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled state, and the exception,
/// if one is encoutered, will be thrown if you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
task<std::vector<_ReturnType>> operator&&(const task<_ReturnType> & _Lhs, const task<_ReturnType> & _Rhs)
{
task<_ReturnType> _PTasks[2] = {_Lhs, _Rhs};
return when_all(_PTasks, _PTasks+2);
}
/// <summary>
/// Creates a task that will complete succesfully when both of the tasks supplied as arguments complete successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when both of the input tasks have completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;&gt;</c>. If the input tasks are of type <c>void</c> the output
/// task will also be a <c>task&lt;void&gt;</c>.
/// <para> To allow for a construct of the sort taskA &amp;&amp; taskB &amp;&amp; taskC, which are combined in pairs, the &amp;&amp; operator
/// produces a <c>task&lt;std::vector&lt;T&gt;&gt;</c> if either one or both of the tasks are of type <c>task&lt;std::vector&lt;T&gt;&gt;</c>.</para>
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled state, and the exception,
/// if one is encoutered, will be thrown if you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
task<std::vector<_ReturnType>> operator&&(const task<std::vector<_ReturnType>> & _Lhs, const task<_ReturnType> & _Rhs)
{
return details::_WhenAllVectorAndValue(_Lhs, _Rhs, true);
}
/// <summary>
/// Creates a task that will complete succesfully when both of the tasks supplied as arguments complete successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when both of the input tasks have completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;&gt;</c>. If the input tasks are of type <c>void</c> the output
/// task will also be a <c>task&lt;void&gt;</c>.
/// <para> To allow for a construct of the sort taskA &amp;&amp; taskB &amp;&amp; taskC, which are combined in pairs, the &amp;&amp; operator
/// produces a <c>task&lt;std::vector&lt;T&gt;&gt;</c> if either one or both of the tasks are of type <c>task&lt;std::vector&lt;T&gt;&gt;</c>.</para>
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled state, and the exception,
/// if one is encoutered, will be thrown if you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
task<std::vector<_ReturnType>> operator&&(const task<_ReturnType> & _Lhs, const task<std::vector<_ReturnType>> & _Rhs)
{
return details::_WhenAllVectorAndValue(_Rhs, _Lhs, false);
}
/// <summary>
/// Creates a task that will complete succesfully when both of the tasks supplied as arguments complete successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when both of the input tasks have completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;&gt;</c>. If the input tasks are of type <c>void</c> the output
/// task will also be a <c>task&lt;void&gt;</c>.
/// <para> To allow for a construct of the sort taskA &amp;&amp; taskB &amp;&amp; taskC, which are combined in pairs, the &amp;&amp; operator
/// produces a <c>task&lt;std::vector&lt;T&gt;&gt;</c> if either one or both of the tasks are of type <c>task&lt;std::vector&lt;T&gt;&gt;</c>.</para>
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled state, and the exception,
/// if one is encoutered, will be thrown if you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
task<std::vector<_ReturnType>> operator&&(const task<std::vector<_ReturnType>> & _Lhs, const task<std::vector<_ReturnType>> & _Rhs)
{
task<std::vector<_ReturnType>> _PTasks[2] = {_Lhs, _Rhs};
return when_all(_PTasks, _PTasks+2);
}
/// <summary>
/// Creates a task that will complete succesfully when both of the tasks supplied as arguments complete successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when both of the input tasks have completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;&gt;</c>. If the input tasks are of type <c>void</c> the output
/// task will also be a <c>task&lt;void&gt;</c>.
/// <para> To allow for a construct of the sort taskA &amp;&amp; taskB &amp;&amp; taskC, which are combined in pairs, the &amp;&amp; operator
/// produces a <c>task&lt;std::vector&lt;T&gt;&gt;</c> if either one or both of the tasks are of type <c>task&lt;std::vector&lt;T&gt;&gt;</c>.</para>
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled state, and the exception,
/// if one is encoutered, will be thrown if you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
inline task<void> operator&&(const task<void> & _Lhs, const task<void> & _Rhs)
{
task<void> _PTasks[2] = {_Lhs, _Rhs};
return when_all(_PTasks, _PTasks+2);
}
namespace details
{
// Helper struct for when_any operators to know when tasks have completed
template <typename _CompletionType>
struct _RunAnyParam
{
_RunAnyParam() : _M_exceptionRelatedToken(nullptr), _M_completeCount(0), _M_numTasks(0), _M_fHasExplicitToken(false)
{
}
~_RunAnyParam()
{
if (_CancellationTokenState::_IsValid(_M_exceptionRelatedToken))
_M_exceptionRelatedToken->_Release();
}
task_completion_event<_CompletionType> _M_Completed;
cancellation_token_source _M_cancellationSource;
_CancellationTokenState * _M_exceptionRelatedToken;
atomic_size_t _M_completeCount;
size_t _M_numTasks;
bool _M_fHasExplicitToken;
};
template<typename _CompletionType, typename _Function, typename _TaskType>
void _WhenAnyContinuationWrapper(_RunAnyParam<_CompletionType> * _PParam, const _Function & _Func, task<_TaskType>& _Task)
{
bool _IsTokenCancled = !_PParam->_M_fHasExplicitToken && _Task._GetImpl()->_M_pTokenState != _CancellationTokenState::_None() && _Task._GetImpl()->_M_pTokenState->_IsCanceled();
if (_Task._GetImpl()->_IsCompleted() && !_IsTokenCancled)
{
_Func();
if (atomic_increment(_PParam->_M_completeCount) == _PParam->_M_numTasks)
{
delete _PParam;
}
}
else
{
_ASSERTE(_Task._GetImpl()->_IsCanceled() || _IsTokenCancled);
if (_Task._GetImpl()->_HasUserException() && !_IsTokenCancled)
{
if (_PParam->_M_Completed._StoreException(_Task._GetImpl()->_GetExceptionHolder()))
{
// This can only enter once.
_PParam->_M_exceptionRelatedToken = _Task._GetImpl()->_M_pTokenState;
_ASSERTE(_PParam->_M_exceptionRelatedToken);
// Deref token will be done in the _PParam destructor.
if (_PParam->_M_exceptionRelatedToken != _CancellationTokenState::_None())
{
_PParam->_M_exceptionRelatedToken->_Reference();
}
}
}
if (atomic_increment(_PParam->_M_completeCount) == _PParam->_M_numTasks)
{
// If no one has be completed so far, we need to make some final cancellation decision.
if (!_PParam->_M_Completed._IsTriggered())
{
// If we already explicit token, we can skip the token join part.
if (!_PParam->_M_fHasExplicitToken)
{
if (_PParam->_M_exceptionRelatedToken)
{
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _PParam->_M_exceptionRelatedToken);
}
else
{
// If haven't captured any exception token yet, there was no exception for all those tasks,
// so just pick a random token (current one) for normal cancellation.
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _Task._GetImpl()->_M_pTokenState);
}
}
// Do exception cancellation or normal cancellation based on whether it has stored exception.
_PParam->_M_Completed._Cancel();
}
delete _PParam;
}
}
}
template<typename _ElementType, typename _Iterator>
struct _WhenAnyImpl
{
static task<std::pair<_ElementType, size_t>> _Perform(const task_options& _TaskOptions, _Iterator _Begin, _Iterator _End)
{
if( _Begin == _End )
{
throw invalid_operation("when_any(begin, end) cannot be called on an empty container.");
}
_CancellationTokenState *_PTokenState = _TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAnyParam<std::pair<std::pair<_ElementType, size_t>, _CancellationTokenState *>>();
if (_PTokenState)
{
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _PTokenState);
_PParam->_M_fHasExplicitToken = true;
}
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_PParam->_M_cancellationSource.get_token());
task<std::pair<std::pair<_ElementType, size_t>, _CancellationTokenState *>> _Any_tasks_completed(_PParam->_M_Completed, _Options);
// Keep a copy ref to the token source
auto _CancellationSource = _PParam->_M_cancellationSource;
_PParam->_M_numTasks = static_cast<size_t>(std::distance(_Begin, _End));
size_t _Index = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_Any_tasks_completed._SetAsync();
}
_PTask->_Then([_PParam, _Index](task<_ElementType> _ResultTask) {
auto _PParamCopy = _PParam; // Dev10
auto _IndexCopy = _Index; // Dev10
auto _Func = [&_ResultTask, _PParamCopy, _IndexCopy]() {
_PParamCopy->_M_Completed.set(std::make_pair(std::make_pair(_ResultTask._GetImpl()->_GetResult(), _IndexCopy), _ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
}, _CancellationTokenState::_None());
_Index++;
}
// All _Any_tasks_completed._SetAsync() must be finished before this return continuation task being created.
return _Any_tasks_completed._Then([=](std::pair<std::pair<_ElementType, size_t>, _CancellationTokenState *> _Result) -> std::pair<_ElementType, size_t> {
_ASSERTE(_Result.second);
if (!_PTokenState)
{
_JoinAllTokens_Add(_CancellationSource, _Result.second);
}
return _Result.first;
}, nullptr);
}
};
template<typename _Iterator>
struct _WhenAnyImpl<void, _Iterator>
{
static task<size_t> _Perform(const task_options& _TaskOptions, _Iterator _Begin, _Iterator _End)
{
if( _Begin == _End )
{
throw invalid_operation("when_any(begin, end) cannot be called on an empty container.");
}
_CancellationTokenState *_PTokenState = _TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAnyParam<std::pair<size_t, _CancellationTokenState *>>();
if (_PTokenState)
{
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _PTokenState);
_PParam->_M_fHasExplicitToken = true;
}
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_PParam->_M_cancellationSource.get_token());
task<std::pair<size_t, _CancellationTokenState *>> _Any_tasks_completed(_PParam->_M_Completed, _Options);
// Keep a copy ref to the token source
auto _CancellationSource = _PParam->_M_cancellationSource;
_PParam->_M_numTasks = static_cast<size_t>(std::distance(_Begin, _End));
size_t _Index = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_Any_tasks_completed._SetAsync();
}
_PTask->_Then([_PParam, _Index](task<void> _ResultTask) {
auto _PParamCopy = _PParam; // Dev10
auto _IndexCopy = _Index; // Dev10
auto _Func = [&_ResultTask, _PParamCopy, _IndexCopy]() {
_PParamCopy->_M_Completed.set(std::make_pair(_IndexCopy, _ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
}, _CancellationTokenState::_None());
_Index++;
}
// All _Any_tasks_completed._SetAsync() must be finished before this return continuation task being created.
return _Any_tasks_completed._Then([=](std::pair<size_t, _CancellationTokenState *> _Result) -> size_t {
_ASSERTE(_Result.second);
if (!_PTokenState)
{
_JoinAllTokens_Add(_CancellationSource, _Result.second);
}
return _Result.first;
}, nullptr);
}
};
} // namespace details
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes successfully.
/// </summary>
/// <typeparam name="_Iterator">
/// The type of the input iterator.
/// </typeparam>
/// <param name="_Begin">
/// The position of the first element in the range of elements to be combined into the resulting task.
/// </param>
/// <param name="_End">
/// The position of the first element beyond the range of elements to be combined into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when any one of the input tasks has completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::pair&lt;T, size_t&gt;&gt;></c>, where the first element of the pair is the result
/// of the completing task, and the second element is the index of the task that finished. If the input tasks are of type <c>void</c>
/// the output is a <c>task&lt;size_t&gt;</c>, where the result is the index of the completing task.
/// </returns>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _Iterator>
auto when_any(_Iterator _Begin, _Iterator _End, const task_options& _TaskOptions = task_options())
-> decltype (details::_WhenAnyImpl<typename std::iterator_traits<_Iterator>::value_type::result_type, _Iterator>::_Perform(_TaskOptions, _Begin, _End))
{
typedef typename std::iterator_traits<_Iterator>::value_type::result_type _ElementType;
return details::_WhenAnyImpl<_ElementType, _Iterator>::_Perform(_TaskOptions, _Begin, _End);
}
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes successfully.
/// </summary>
/// <typeparam name="_Iterator">
/// The type of the input iterator.
/// </typeparam>
/// <param name="_Begin">
/// The position of the first element in the range of elements to be combined into the resulting task.
/// </param>
/// <param name="_End">
/// The position of the first element beyond the range of elements to be combined into the resulting task.
/// </param>
/// <param name="_CancellationToken">
/// The cancellation token which controls cancellation of the returned task. If you do not provide a cancellation token, the resulting
/// task will receive the cancellation token of the task that causes it to complete.
/// </param>
/// <returns>
/// A task that completes successfully when any one of the input tasks has completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::pair&lt;T, size_t&gt;&gt;></c>, where the first element of the pair is the result
/// of the completing task, and the second element is the index of the task that finished. If the input tasks are of type <c>void</c>
/// the output is a <c>task&lt;size_t&gt;</c>, where the result is the index of the completing task.
/// </returns>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _Iterator>
auto when_any(_Iterator _Begin, _Iterator _End, cancellation_token _CancellationToken)
-> decltype (details::_WhenAnyImpl<typename std::iterator_traits<_Iterator>::value_type::result_type, _Iterator>::_Perform(_CancellationToken._GetImplValue(), _Begin, _End))
{
typedef typename std::iterator_traits<_Iterator>::value_type::result_type _ElementType;
return details::_WhenAnyImpl<_ElementType, _Iterator>::_Perform(_CancellationToken._GetImplValue(), _Begin, _End);
}
/// <summary>
/// Creates a task that will complete successfully when either of the tasks supplied as arguments completes successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes sucessfully when either of the input tasks has completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;</c>. If the input tasks are of type <c>void</c> the output task
/// will also be a <c>task&lt;void&gt;</c>.
/// <para> To allow for a construct of the sort taskA || taskB &amp;&amp; taskC, which are combined in pairs, with &amp;&amp; taking precedence
/// over ||, the operator|| produces a <c>task&lt;std::vector&lt;T&gt;&gt;</c> if one of the tasks is of type <c>task&lt;std::vector&lt;T&gt;&gt;</c>
/// and the other one is of type <c>task&lt;T&gt;.</c></para>
/// </returns>
/// <remarks>
/// If both of the tasks are canceled or throw exceptions, the returned task will complete in the canceled state, and one of the exceptions,
/// if any are encountered, will be thrown when you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
task<_ReturnType> operator||(const task<_ReturnType> & _Lhs, const task<_ReturnType> & _Rhs)
{
auto _PParam = new details::_RunAnyParam<std::pair<_ReturnType, size_t>>();
task<std::pair<_ReturnType, size_t>> _Any_tasks_completed(_PParam->_M_Completed, _PParam->_M_cancellationSource.get_token());
// Chain the return continuation task here to ensure it will get inline execution when _M_Completed.set is called,
// So that _PParam can be used before it getting deleted.
auto _ReturnTask = _Any_tasks_completed._Then([=](std::pair<_ReturnType, size_t> _Ret) -> _ReturnType {
_ASSERTE(_Ret.second);
_JoinAllTokens_Add(_PParam->_M_cancellationSource, reinterpret_cast<details::_CancellationTokenState *>(_Ret.second));
return _Ret.first;
}, nullptr);
if (_Lhs.is_apartment_aware() || _Rhs.is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PParam->_M_numTasks = 2;
auto _Continuation = [_PParam](task<_ReturnType> _ResultTask) {
// Dev10 compiler bug
auto _PParamCopy = _PParam;
auto _Func = [&_ResultTask, _PParamCopy]() {
_PParamCopy->_M_Completed.set(std::make_pair(_ResultTask._GetImpl()->_GetResult(), reinterpret_cast<size_t>(_ResultTask._GetImpl()->_M_pTokenState)));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
};
_Lhs._Then(_Continuation, details::_CancellationTokenState::_None());
_Rhs._Then(_Continuation, details::_CancellationTokenState::_None());
return _ReturnTask;
}
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes sucessfully when either of the input tasks has completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;</c>. If the input tasks are of type <c>void</c> the output task
/// will also be a <c>task&lt;void&gt;</c>.
/// <para> To allow for a construct of the sort taskA || taskB &amp;&amp; taskC, which are combined in pairs, with &amp;&amp; taking precedence
/// over ||, the operator|| produces a <c>task&lt;std::vector&lt;T&gt;&gt;</c> if one of the tasks is of type <c>task&lt;std::vector&lt;T&gt;&gt;</c>
/// and the other one is of type <c>task&lt;T&gt;.</c></para>
/// </returns>
/// <remarks>
/// If both of the tasks are canceled or throw exceptions, the returned task will complete in the canceled state, and one of the exceptions,
/// if any are encountered, will be thrown when you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
task<std::vector<_ReturnType>> operator||(const task<std::vector<_ReturnType>> & _Lhs, const task<_ReturnType> & _Rhs)
{
auto _PParam = new details::_RunAnyParam<std::pair<std::vector<_ReturnType>, details::_CancellationTokenState *>>();
task<std::pair<std::vector<_ReturnType>, details::_CancellationTokenState *>> _Any_tasks_completed(_PParam->_M_Completed, _PParam->_M_cancellationSource.get_token());
// Chain the return continuation task here to ensure it will get inline execution when _M_Completed.set is called,
// So that _PParam can be used before it getting deleted.
auto _ReturnTask = _Any_tasks_completed._Then([=](std::pair<std::vector<_ReturnType>, details::_CancellationTokenState *> _Ret) -> std::vector<_ReturnType> {
_ASSERTE(_Ret.second);
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _Ret.second);
return _Ret.first;
}, nullptr);
if (_Lhs.is_apartment_aware() || _Rhs.is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PParam->_M_numTasks = 2;
_Lhs._Then([_PParam](task<std::vector<_ReturnType>> _ResultTask) {
// Dev10 compiler bug
auto _PParamCopy = _PParam;
auto _Func = [&_ResultTask, _PParamCopy]() {
auto _Result = _ResultTask._GetImpl()->_GetResult();
_PParamCopy->_M_Completed.set(std::make_pair(_Result, _ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
}, details::_CancellationTokenState::_None());
_Rhs._Then([_PParam](task<_ReturnType> _ResultTask)
{
// Dev10 compiler bug
typedef _ReturnType _ReturnTypeDev10;
auto _PParamCopy = _PParam;
auto _Func = [&_ResultTask, _PParamCopy]() {
auto _Result = _ResultTask._GetImpl()->_GetResult();
std::vector<_ReturnTypeDev10> _Vec;
_Vec.push_back(_Result);
_PParamCopy->_M_Completed.set(std::make_pair(_Vec, _ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
}, details::_CancellationTokenState::_None());
return _ReturnTask;
}
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes sucessfully when either of the input tasks has completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;</c>. If the input tasks are of type <c>void</c> the output task
/// will also be a <c>task&lt;void&gt;</c>.
/// <para> To allow for a construct of the sort taskA || taskB &amp;&amp; taskC, which are combined in pairs, with &amp;&amp; taking precedence
/// over ||, the operator|| produces a <c>task&lt;std::vector&lt;T&gt;&gt;</c> if one of the tasks is of type <c>task&lt;std::vector&lt;T&gt;&gt;</c>
/// and the other one is of type <c>task&lt;T&gt;.</c></para>
/// </returns>
/// <remarks>
/// If both of the tasks are canceled or throw exceptions, the returned task will complete in the canceled state, and one of the exceptions,
/// if any are encountered, will be thrown when you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
task<std::vector<_ReturnType>> operator||(const task<_ReturnType> & _Lhs, const task<std::vector<_ReturnType>> & _Rhs)
{
return _Rhs || _Lhs;
}
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes sucessfully when either of the input tasks has completed successfully. If the input tasks are of type <c>T</c>,
/// the output of this function will be a <c>task&lt;std::vector&lt;T&gt;</c>. If the input tasks are of type <c>void</c> the output task
/// will also be a <c>task&lt;void&gt;</c>.
/// <para> To allow for a construct of the sort taskA || taskB &amp;&amp; taskC, which are combined in pairs, with &amp;&amp; taking precedence
/// over ||, the operator|| produces a <c>task&lt;std::vector&lt;T&gt;&gt;</c> if one of the tasks is of type <c>task&lt;std::vector&lt;T&gt;&gt;</c>
/// and the other one is of type <c>task&lt;T&gt;.</c></para>
/// </returns>
/// <remarks>
/// If both of the tasks are canceled or throw exceptions, the returned task will complete in the canceled state, and one of the exceptions,
/// if any are encountered, will be thrown when you call <c>get()</c> or <c>wait()</c> on that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
inline task<void> operator||(const task<void> & _Lhs, const task<void> & _Rhs)
{
auto _PParam = new details::_RunAnyParam<std::pair<details::_Unit_type, details::_CancellationTokenState *>>();
task<std::pair<details::_Unit_type, details::_CancellationTokenState *>> _Any_task_completed(_PParam->_M_Completed, _PParam->_M_cancellationSource.get_token());
// Chain the return continuation task here to ensure it will get inline execution when _M_Completed.set is called,
// So that _PParam can be used before it getting deleted.
auto _ReturnTask = _Any_task_completed._Then([=](std::pair<details::_Unit_type, details::_CancellationTokenState *> _Ret) {
_ASSERTE(_Ret.second);
details::_JoinAllTokens_Add(_PParam->_M_cancellationSource, _Ret.second);
}, nullptr);
if (_Lhs.is_apartment_aware() || _Rhs.is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PParam->_M_numTasks = 2;
auto _Continuation = [_PParam](task<void> _ResultTask) mutable {
// Dev10 compiler needs this.
auto _PParam1 = _PParam;
auto _Func = [&_ResultTask, _PParam1]() {
_PParam1->_M_Completed.set(std::make_pair(details::_Unit_type(), _ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
};
_Lhs._Then(_Continuation, details::_CancellationTokenState::_None());
_Rhs._Then(_Continuation, details::_CancellationTokenState::_None());
return _ReturnTask;
}
template<typename _Ty>
task<_Ty> task_from_result(_Ty _Param, const task_options& _TaskOptions = task_options())
{
task_completion_event<_Ty> _Tce;
_Tce.set(_Param);
return create_task(_Tce, _TaskOptions);
}
// Work around VS 2010 compiler bug
#if _MSC_VER == 1600
inline task<bool> task_from_result(bool _Param)
{
task_completion_event<bool> _Tce;
_Tce.set(_Param);
return create_task(_Tce, task_options());
}
#endif
inline task<void> task_from_result(const task_options& _TaskOptions = task_options())
{
task_completion_event<void> _Tce;
_Tce.set();
return create_task(_Tce, _TaskOptions);
}
template<typename _TaskType, typename _ExType>
task<_TaskType> task_from_exception(_ExType _Exception, const task_options& _TaskOptions = task_options())
{
task_completion_event<_TaskType> _Tce;
_Tce.set_exception(_Exception);
return create_task(_Tce, _TaskOptions);
}
namespace details
{
/// <summary>
/// A convenient extension to Concurrency: loop until a condition is no longer met
/// </summary>
/// <param name="func">
/// A function representing the body of the loop. It will be invoked at least once and
/// then repetitively as long as it returns true.
/// </param>
inline
task<bool> do_while(std::function<task<bool>(void)> func)
{
task<bool> first = func();
return first.then([=](bool guard) -> task<bool> {
if (guard)
return do_while(func);
else
return first;
});
}
} // namespace details
} // namespace Concurrency
#pragma pop_macro("new")
#pragma warning(pop)
#pragma pack(pop)
#endif // _PPLTASKS_H