Concurrency::task_continuation_context Class Reference

The task_continuation_context 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. More...

#include <ppltasks.h>

Inheritance diagram for Concurrency::task_continuation_context:

Static Public Member Functions
static task_continuation_context	use_default ()
	Creates the default task continuation context. More...
Static Public Member Functions inherited from Concurrency::details::_ContextCallback
static _ContextCallback	_CaptureCurrent ()

Private Member Functions
	task_continuation_context (bool _DeferCapture=false)

Additional Inherited Members
Public Member Functions inherited from Concurrency::details::_ContextCallback
	_ContextCallback (bool=false)
	_ContextCallback (const _ContextCallback &)
	_ContextCallback (_ContextCallback &&)
_ContextCallback &	operator= (const _ContextCallback &)
_ContextCallback &	operator= (_ContextCallback &&)
bool	_HasCapturedContext () const
void	_Resolve (bool) const
void	_CallInContext (_CallbackFunction _Func) const
bool	operator== (const _ContextCallback &) const
bool	operator!= (const _ContextCallback &) const

Detailed Description

The task_continuation_context 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.

See also

task Class

Constructor & Destructor Documentation

Concurrency::task_continuation_context::task_continuation_context ( bool  _DeferCapture = false )

inlineprivate

                                                          : details::_ContextCallback(_DeferCapture)
    {
    }

Member Function Documentation

static task_continuation_context Concurrency::task_continuation_context::use_default ( )

inlinestatic

Creates the default task continuation context.

Returns

The default continuation context.

The default context is used if you don't specifiy a continuation context when you call the then 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 then is invoked.

An apartment aware task is a task that unwraps a Windows Runtime IAsyncInfo 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.

A continuation on a non-apartment aware task will execute in a context the Runtime chooses.

    {
#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) */
    }

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The documentation for this class was generated from the following file:

• VS2013/inc/ppltasks.h