Urho3D::WorkQueue Class Reference

Work queue subsystem for multithreading. More...

#include <Urho3D/Core/WorkQueue.h>

Inheritance diagram for Urho3D::WorkQueue:

Collaboration diagram for Urho3D::WorkQueue:

Public Member Functions
	WorkQueue (Context *context)
	Construct.
	~WorkQueue () override
	Destruct.
void	CreateThreads (unsigned numThreads)
	Create worker threads. Can only be called once.
SharedPtr< WorkItem >	GetFreeItem ()
	Get pointer to an usable WorkItem from the item pool. Allocate one if no more free items.
void	AddWorkItem (const SharedPtr< WorkItem > &item)
	Add a work item and resume worker threads.
bool	RemoveWorkItem (SharedPtr< WorkItem > item)
	Remove a work item before it has started executing. Return true if successfully removed.
unsigned	RemoveWorkItems (const Vector< SharedPtr< WorkItem > > &items)
	Remove a number of work items before they have started executing. Return the number of items successfully removed.
void	Pause ()
	Pause worker threads.
void	Resume ()
	Resume worker threads.
void	Complete (unsigned priority)
	Finish all queued work which has at least the specified priority. Main thread will also execute priority work. Pause worker threads if no more work remains.
void	SetTolerance (int tolerance)
	Set the pool telerance before it starts deleting pool items.
void	SetNonThreadedWorkMs (int ms)
	Set how many milliseconds maximum per frame to spend on low-priority work, when there are no worker threads.
unsigned	GetNumThreads () const
	Return number of worker threads.
bool	IsCompleted (unsigned priority) const
	Return whether all work with at least the specified priority is finished.
bool	IsCompleting () const
	Return whether the queue is currently completing work in the main thread.
int	GetTolerance () const
	Return the pool tolerance.
int	GetNonThreadedWorkMs () const
	Return how many milliseconds maximum to spend on non-threaded low-priority work.
Public Member Functions inherited from Urho3D::Object
	Object (Context *context)
	Construct.
	~Object () override
	Destruct. Clean up self from event sender & receiver structures.
virtual StringHash	GetType () const =0
virtual const String &	GetTypeName () const =0
virtual const TypeInfo *	GetTypeInfo () const =0
	Return type info.
virtual void	OnEvent (Object *sender, StringHash eventType, VariantMap &eventData)
	Handle event.
bool	IsInstanceOf (StringHash type) const
	Check current instance is type of specified type.
bool	IsInstanceOf (const TypeInfo *typeInfo) const
	Check current instance is type of specified type.
template<typename T >
bool	IsInstanceOf () const
	Check current instance is type of specified class.
template<typename T >
T *	Cast ()
	Cast the object to specified most derived class.
template<typename T >
const T *	Cast () const
	Cast the object to specified most derived class.
void	SubscribeToEvent (StringHash eventType, EventHandler *handler)
	Subscribe to an event that can be sent by any sender.
void	SubscribeToEvent (Object *sender, StringHash eventType, EventHandler *handler)
	Subscribe to a specific sender's event.
void	SubscribeToEvent (StringHash eventType, const std::function< void(StringHash, VariantMap &)> &function, void *userData=nullptr)
	Subscribe to an event that can be sent by any sender.
void	SubscribeToEvent (Object *sender, StringHash eventType, const std::function< void(StringHash, VariantMap &)> &function, void *userData=nullptr)
	Subscribe to a specific sender's event.
void	UnsubscribeFromEvent (StringHash eventType)
	Unsubscribe from an event.
void	UnsubscribeFromEvent (Object *sender, StringHash eventType)
	Unsubscribe from a specific sender's event.
void	UnsubscribeFromEvents (Object *sender)
	Unsubscribe from a specific sender's events.
void	UnsubscribeFromAllEvents ()
	Unsubscribe from all events.
void	UnsubscribeFromAllEventsExcept (const PODVector< StringHash > &exceptions, bool onlyUserData)
	Unsubscribe from all events except those listed, and optionally only those with userdata (script registered events).
void	SendEvent (StringHash eventType)
	Send event to all subscribers.
void	SendEvent (StringHash eventType, VariantMap &eventData)
	Send event with parameters to all subscribers.
VariantMap &	GetEventDataMap () const
	Return a preallocated map for event data. Used for optimization to avoid constant re-allocation of event data maps.
template<typename... Args>
void	SendEvent (StringHash eventType, Args... args)
	Send event with variadic parameter pairs to all subscribers. The parameter pairs is a list of paramID and paramValue separated by comma, one pair after another.
Context *	GetContext () const
	Return execution context.
const Variant &	GetGlobalVar (StringHash key) const
const VariantMap &	GetGlobalVars () const
void	SetGlobalVar (StringHash key, const Variant &value)
Object *	GetSubsystem (StringHash type) const
	Return subsystem by type.
Object *	GetEventSender () const
	Return active event sender. Null outside event handling.
EventHandler *	GetEventHandler () const
	Return active event handler. Null outside event handling.
bool	HasSubscribedToEvent (StringHash eventType) const
	Return whether has subscribed to an event without specific sender.
bool	HasSubscribedToEvent (Object *sender, StringHash eventType) const
	Return whether has subscribed to a specific sender's event.
bool	HasEventHandlers () const
	Return whether has subscribed to any event.
template<class T >
T *	GetSubsystem () const
	Template version of returning a subsystem.
const String &	GetCategory () const
void	SetBlockEvents (bool block)
	Block object from sending and receiving events.
bool	GetBlockEvents () const
	Return sending and receiving events blocking status.
Public Member Functions inherited from Urho3D::RefCounted
	RefCounted ()
	Construct. Allocate the reference count structure and set an initial self weak reference.
virtual	~RefCounted ()
	Destruct. Mark as expired and also delete the reference count structure if no outside weak references exist.
	RefCounted (const RefCounted &rhs)=delete
	Prevent copy construction.
RefCounted &	operator= (const RefCounted &rhs)=delete
	Prevent assignment.
void	AddRef ()
	Increment reference count. Can also be called outside of a SharedPtr for traditional reference counting.
void	ReleaseRef ()
	Decrement reference count and delete self if no more references. Can also be called outside of a SharedPtr for traditional reference counting.
int	Refs () const
int	WeakRefs () const
RefCount *	RefCountPtr ()
	Return pointer to the reference count structure.

Private Member Functions
	URHO3D_OBJECT (WorkQueue, Object)
void	ProcessItems (unsigned threadIndex)
	Process work items until shut down. Called by the worker threads.
void	PurgeCompleted (unsigned priority)
	Purge completed work items which have at least the specified priority, and send completion events as necessary.
void	PurgePool ()
	Purge the pool to reduce allocation where its unneeded.
void	ReturnToPool (SharedPtr< WorkItem > &item)
	Return a work item to the pool.
void	HandleBeginFrame (StringHash eventType, VariantMap &eventData)
	Handle frame start event. Purge completed work from the main thread queue, and perform work if no threads at all.

Private Attributes
Vector< SharedPtr< WorkerThread > >	threads_
	Worker threads.
List< SharedPtr< WorkItem > >	poolItems_
	Work item pool for reuse to cut down on allocation. The bool is a flag for item pooling and whether it is available or not.
List< SharedPtr< WorkItem > >	workItems_
	Work item collection. Accessed only by the main thread.
List< WorkItem * >	queue_
	Work item prioritized queue for worker threads. Pointers are guaranteed to be valid (point to workItems).
Mutex	queueMutex_
	Worker queue mutex.
std::atomic< bool >	shutDown_
	Shutting down flag.
std::atomic< bool >	pausing_
	Pausing flag. Indicates the worker threads should not contend for the queue mutex.
bool	paused_
	Paused flag. Indicates the queue mutex being locked to prevent worker threads using up CPU time.
bool	completing_
	Completing work in the main thread flag.
int	tolerance_
	Tolerance for the shared pool before it begins to deallocate.
unsigned	lastSize_
	Last size of the shared pool.
int	maxNonThreadedWorkMs_
	Maximum milliseconds per frame to spend on low-priority work, when there are no worker threads.

Friends
class	WorkerThread

Additional Inherited Members
Static Public Member Functions inherited from Urho3D::Object
static const TypeInfo *	GetTypeInfoStatic ()
	Return type info static.
Protected Attributes inherited from Urho3D::Object
Context *	context_
	Execution context.

Detailed Description

Work queue subsystem for multithreading.

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

• Source/Urho3D/Core/WorkQueue.h
• Source/Urho3D/Core/WorkQueue.cpp