FAsyncTaskBase | Unreal Engine 5.7 Documentation

FAsyncTask - template task for jobs queued to thread pools

Sample code:

class ExampleAsyncTask : public FNonAbandonableTask { friend class FAsyncTask;

int32 ExampleData;

ExampleAsyncTask(int32 InExampleData) : ExampleData(InExampleData) { }

void DoWork() { ... do the work here }

FORCEINLINE TStatId GetStatId() const { RETURN_QUICK_DECLARE_CYCLE_STAT(ExampleAsyncTask, STATGROUP_ThreadPoolAsyncTasks); } };

void Example() {

start an example job FAsyncTask* MyTask = new FAsyncTask( 5 ); MyTask->StartBackgroundTask();

or MyTask->StartSynchronousTask();

/to just do it now on this thread /Check if the task is done : if (MyTask->IsDone()) { }

/Spinning on IsDone is not acceptable( see EnsureCompletion ), but it is ok to check once a frame. /Ensure the task is done, doing the task on the current thread if it has not been started, waiting until completion in all cases. MyTask->EnsureCompletion(); delete Task; }


Name	FAsyncTaskBase
Type	class
Header File	/Engine/Source/Runtime/Core/Public/Async/AsyncWork.h
Include Path	#include "Async/AsyncWork.h"

Syntax

class FAsyncTaskBase :  
    private UE::FInheritedContextBase ,  
    private IQueuedWork

Inheritance Hierarchy

FInheritedContextBase → FAsyncTaskBase

Implements Interfaces

IQueuedWork

Derived Classes

FAsyncTask

Destructors

Name	Remarks	Include Path	Unreal Specifiers
virtual ~FAsyncTaskBase()	Destructor, not legal when a task is in process	Async/AsyncWork.h

Variables

Protected

Name	Type	Remarks	Include Path
DebugName	const TCHAR *	Text to identify the Task; used for debug/log purposes only.	Async/AsyncWork.h
DoneEvent	FEvent *	If we aren't doing the work synchronously, this will hold the completion event	Async/AsyncWork.h
Flags	EQueuedWorkFlags	Current flags	Async/AsyncWork.h
Priority	EQueuedWorkPriority	Current priority	Async/AsyncWork.h
QueuedPool	FQueuedThreadPool *	Pool we are queued into, maintained by the calling thread	Async/AsyncWork.h
RequiredMemory	int64	Approximation of the peak memory (in bytes) this task could require during it's execution.	Async/AsyncWork.h
StatId	TStatId	StatId used for FScopeCycleCounter	Async/AsyncWork.h
WorkNotFinishedCounter	FThreadSafeCounter	Thread safe counter that indicates WORK completion, no necessarily finalization of the job	Async/AsyncWork.h

Functions

Public

Name	Remarks	Include Path
bool Cancel ()	Cancel the task, if possible.	Async/AsyncWork.h
void EnsureCompletion ( bool bDoWorkOnThisThreadIfNotStarted, bool bIsLatencySensitive )	Wait until the job is complete	Async/AsyncWork.h
EQueuedWorkPriority GetPriority()		Async/AsyncWork.h
bool IsDone ()	Returns true if the work and TASK has completed, false while it's still in progress.	Async/AsyncWork.h
bool IsIdle ()	Returns true if the work has not been started or has been completed.	Async/AsyncWork.h
bool IsWorkDone ()	Returns true if the work has completed, false while it's still in progress.	Async/AsyncWork.h
bool Reschedule ( FQueuedThreadPool* InQueuedPool, EQueuedWorkPriority InQueuedWorkPriority )	If not already being processed, will be rescheduled on given thread pool and priority.	Async/AsyncWork.h
bool SetPriority ( EQueuedWorkPriority QueuedWorkPriority )		Async/AsyncWork.h
void StartBackgroundTask ( FQueuedThreadPool* InQueuedPool, EQueuedWorkPriority InQueuedWorkPriority, EQueuedWorkFlags InQueuedWorkFlags, int64 InRequiredMemory, const TCHAR* InDebugName )	Queue this task for processing by the background thread pool	Async/AsyncWork.h
void StartSynchronousTask ( EQueuedWorkPriority InQueuedWorkPriority, EQueuedWorkFlags InQueuedWorkFlags, int64 InRequiredMemory, const TCHAR* InDebugName )	Run this task on this thread	Async/AsyncWork.h
bool WaitCompletionWithTimeout ( float TimeLimitSeconds )	Wait until the job is complete, up to a time limit	Async/AsyncWork.h

Overridden from IQueuedWork

Name	Remarks	Include Path	Unreal Specifiers
virtual const TCHAR * GetDebugName()	Returns text to identify the Work, for debug/log purposes only	Async/AsyncWork.h
virtual int64 GetRequiredMemory()	Returns an approximation of the peak memory (in bytes) this task could require during it's execution.	Async/AsyncWork.h

Protected

Name	Remarks	Include Path
void CheckIdle()	Internal call to assert that we are idle	Async/AsyncWork.h
void DoTaskWork()	Perform task's work	Async/AsyncWork.h
void Init ( TStatId InStatId )		Async/AsyncWork.h
virtual void MarkAsCanceled()	Mark the task as canceled (i.e. no longer needed).	Async/AsyncWork.h
bool TryAbandonTask()	Abandon task if possible, returns true on success, false otherwise.	Async/AsyncWork.h

Navigation

Syntax

Inheritance Hierarchy

Implements Interfaces

Derived Classes

Destructors

Variables

Protected

Functions

Public

Overridden from IQueuedWork

Protected