FOnlineAsyncTaskManager | Unreal Engine 5.4 Documentation

Unreal Engine C++ API Reference > Plugins > OnlineSubsystem

Inheritance Hierarchy

FRunnable
FSingleThreadRunnable
FOnlineAsyncTaskManager

References


Module	OnlineSubsystem
Header	/Engine/Plugins/Online/OnlineSubsystem/Source/Public/OnlineAsyncTaskManager.h
Include	#include "OnlineAsyncTaskManager.h"

Syntax

class FOnlineAsyncTaskManager :  
    public FRunnable ,  
    private FSingleThreadRunnable

Remarks

The foundation of all async operations in every online subsystem

A task manager ticks on its own thread, managing both a serial and parallel queue of FOnlineAsyncTasks Each task works through the serial queue in the following manner GameThread

Initialize() OnlineThread Tick() until IsDone() Add task to OutQueue GameThread
Finalize()
TriggerDelegates()

Parallel task queue works in a similar flow, except the tasks don't wait for any previous tasks to complete

Variables

Type	Name	Description
std::atomic< bool >	bReloadMaxParallelTasksConfig	Signal game thread to reload the MaxParallelTasks value from config
FThreadSafeBool	bRequestingExit	Should this manager and the thread exit
int32	MaxParallelTasks	Number of tasks that can run in parallel
volatile uint32	OnlineThreadId	Set by FOnlineAsyncTaskManager::Run
TArray< FOnlineAsyncItem * >	OutQueue	Completed online requests are queued up here for processing on the game thread
FCriticalSection	OutQueueLock	Critical section for thread safe operation of the out queue
TArray< FOnlineAsyncTask * >	ParallelTasks	Tasks that are running in parallel
FCriticalSection	ParallelTasksLock	Critical section for thread safe operation of the list
uint32	PollingInterval	Min amount of time to poll for the current task to complete
TQueue< FOnlineAsyncTask *, EQueueMode::Mpsc >	QueuedParallelTasks	This queue is for tasks that are safe to run in parallel with one another
TArray< FOnlineAsyncTask * >	QueuedSerialTasks	Game thread async tasks are queued up here for processing on the online thread
FCriticalSection	QueuedSerialTasksLock	Critical section for thread safe operation of the event in queue
FEvent *	WorkEvent	Trigger event to signal the queue has tasks that need processing

Constructors

	Type	Name	Description
		FOnlineAsyncTaskManager ()

Destructors

	Type	Name	Description
		~FOnlineAsyncTaskManager ()

Functions

Type	Name	Description
void	AddGenericToInQueue ( const CallableType& InCallable )	Add a new item to the in queue that will call InCallable on the game thread.
void	AddGenericToInQueueOnlineThread ( const FString& CallableName, const CallableType& InCallable )	Add a new item to the in queue that will call InCallable on the ONLINE thread.
void	AddGenericToOutQueue ( const CallableType& InCallable )	Add a new item to the out queue that will call InCallable on the game thread.
void	AddToInQueue ( FOnlineAsyncTask* NewTask )	Add online async tasks that need processing onto the incoming queue
void	AddToOutQueue ( FOnlineAsyncItem* CompletedItem )	Add completed online async tasks that need processing onto the queue
void	AddToParallelTasks ( FOnlineAsyncTask* NewTask )	Add a new online async task that is safe to run in parallel
void	GameTick ()	CALL ONLY FROM GAME THREAD Give the completed async tasks a chance to marshal their data back onto the game thread Calling delegates where appropriate
void	OnlineTick ()	CALL ONLY FROM ONLINE THREAD Give the online service a chance to do work
void	RemoveFromParallelTasks ( FOnlineAsyncTask* OldTask )	Remove a parallel async task from the parallel queue

Overridden from FRunnable

Type	Name	Description
void	Exit ()	Called in the context of the aggregating thread to perform any cleanup.
FSingleThreadRunnable *	GetSingleThreadInterface ()	FSingleThreadRunnable accessor for ticking this FRunnable when multi-threading is disabled.
bool	Init ()	Init the online async task manager
uint32	Run ()	This is where all per object thread work is done.
void	Stop ()	This is called if a thread is requested to terminate early