#include <itkOpenCLUserEvent.h>

Detailed Description

The OpenCLUserEvent class represents OpenCL user events.

User events allow applications to enqueue commands that wait on a user event to finish before the command is executed by the device. Commands that depend upon the user event will not be executed until the application triggers the user event with SetComplete(). User events are constructed with OpenCLContext::CreateUserEvent().

OpenCLBuffer buffer = context->CreateBufferDevice(size, OpenCLMemoryObject::WriteOnly);
OpenCLUserEvent user_event = context->CreateUserEvent();
OpenCLEventList events;
events << user_event;
OpenCLEvent event1 = buffer.WriteAsync(..., events, ...);
OpenCLEvent event2 = buffer.WriteAsync(..., events, ...);
events << event1 << event2;
user_event.SetComplete();

Note: Developers should be careful when releasing their last reference count on events created by OpenCLContext::CreateUserEvent() that have not yet been set to status of {CL_COMPLETE} or an error. If the user event was used in the OpenCLEventList argument passed to a clEnqueue*** API or another application host thread is waiting for it in OpenCLEvent::WaitForFinished(), those commands and host threads will continue to wait for the event status to reach {CL_COMPLETE} or error, even after the user has released the object. Since in this scenario the developer has released his last reference count to the user event, it would be in principle no longer valid for him to change the status of the event to unblock all the other machinery. As a result the waiting tasks will wait forever, and associated events, cl_mem objects, command queues and contexts are likely to leak. In-order command queues caught up in this deadlock may cease to do any work.

See also: OpenCLEvent, OpenCLContext::CreateUserEvent()

Definition at line 66 of file itkOpenCLUserEvent.h.

Inheritance diagram for itk::OpenCLUserEvent:

Public Types
typedef OpenCLUserEvent	Self

Public Types inherited from itk::OpenCLEvent
typedef OpenCLEvent	Self

Public Member Functions
	OpenCLUserEvent ()

	OpenCLUserEvent (cl_event id)

	OpenCLUserEvent (const OpenCLEvent &other)

OpenCLUserEvent &	operator= (const OpenCLEvent &other)

void	SetComplete ()

void	SetStatus (const cl_int status)

Public Member Functions inherited from itk::OpenCLEvent
cl_command_type	GetCommandType () const

cl_event	GetEventId () const

cl_ulong	GetFinishTime () const

cl_ulong	GetQueueTime () const

cl_ulong	GetRunTime () const

cl_int	GetStatus () const

cl_ulong	GetSubmitTime () const

bool	IsComplete () const

bool	IsError () const

bool	IsNull () const

bool	IsQueued () const

bool	IsRunning () const

bool	IsSubmitted () const

	OpenCLEvent ()

	OpenCLEvent (const cl_event id)

	OpenCLEvent (const OpenCLEvent &other)

OpenCLEvent &	operator= (const OpenCLEvent &other)

cl_int	SetCallback (cl_int type, void(CL_CALLBACK pfn_notify)(cl_event, cl_int, void ), void *user_data=nullptr)

cl_int	WaitForFinished ()

	~OpenCLEvent ()

Private Member Functions
	OpenCLUserEvent (cl_event id, bool)

void	ReleaseIfNotUserEvent ()

Friends
class	OpenCLContext

Member Typedef Documentation

◆ Self

typedef OpenCLUserEvent itk::OpenCLUserEvent::Self

Standard class typedefs.

Definition at line 71 of file itkOpenCLUserEvent.h.

Constructor & Destructor Documentation

◆ OpenCLUserEvent() [1/4]

itk::OpenCLUserEvent::OpenCLUserEvent ( )

inline

Constructs a null user event.

Definition at line 74 of file itkOpenCLUserEvent.h.

◆ OpenCLUserEvent() [2/4]

itk::OpenCLUserEvent::OpenCLUserEvent ( cl_event id )

Constructs an OpenCL event object from the native identifier id. This class takes over ownership of id and will release it in the destructor. If id is not a user event, then the newly constructed event will be set to null, and id will be released.

◆ OpenCLUserEvent() [3/4]

itk::OpenCLUserEvent::OpenCLUserEvent ( const OpenCLEvent & other )

Constructs a copy of other. The {clRetainEvent()} function will be called to update the reference count on GetEventId(). If other is not a user event, then the newly constructed event will be set to null.

◆ OpenCLUserEvent() [4/4]

itk::OpenCLUserEvent::OpenCLUserEvent	(	cl_event	id,
		bool
	)

inlineprivate

Definition at line 112 of file itkOpenCLUserEvent.h.

Member Function Documentation

◆ operator=()

OpenCLUserEvent & itk::OpenCLUserEvent::operator= ( const OpenCLEvent & other )

Assigns other to this OpenCL event object. The current GetEventId() will be released with {clReleaseEvent()}, and the new GetEventId() will be retained with {clRetainEvent()}. If other is not a user event, then this event will be set to null.

◆ ReleaseIfNotUserEvent()

void itk::OpenCLUserEvent::ReleaseIfNotUserEvent ( )

private

Checks the event type agains {CL_COMMAND_USER} and release it if not.

◆ SetComplete()

void itk::OpenCLUserEvent::SetComplete ( )

Sets this user event to the complete state. Any queued commands that depend upon this event can now proceed.

See also: SetStatus()

◆ SetStatus()

void itk::OpenCLUserEvent::SetStatus ( const cl_int status )

Sets the status of this user event. The status should be either {CL_COMPLETE} or a negative OpenCL error code.

See also: SetComplete()

Friends And Related Function Documentation

◆ OpenCLContext

friend class OpenCLContext

friend

friends from OpenCL core

Definition at line 116 of file itkOpenCLUserEvent.h.