NAME

       clCreateEventFromGLsyncKHR - Creates an event object linked to an OpenGL sync object.

       cl_event clCreateEventFromGLsyncKHR(cl_context context, GLsync sync, cl_int *errcode_ret);

PARAMETERS

        context
           A valid OpenCL context created from an OpenGL context or share group, using the
           cl_khr_gl_sharing(3clc) extension.

        sync
           The name of a sync object in the GL share group associated with context.

DESCRIPTION

       An event object may be created by linking to an OpenGL sync object. Completion of such an
       event object is equivalent to waiting for completion of the fence command associated with
       the linked GL sync object.

NOTES

       The parameters of an event object linked to a GL sync object will return the following
       values when queried with clGetEventInfo(3clc):

       •    The CL_EVENT_COMMAND_QUEUE of a linked event is NULL, because the event is not
           associated with any OpenCL command queue.

       •    The CL_EVENT_COMMAND_TYPE of a linked event is CL_COMMAND_GL_FENCE_SYNC_OBJECT_KHR,
           indicating that the event is associated with a GL sync object, rather than an OpenCL
           command.

       •    The CL_EVENT_COMMAND_EXECUTION_STATUS of a linked event is either CL_SUBMITTED,
           indicating that the fence command associated with the sync object has  not yet
           completed, or CL_COMPLETE, indicating that the fence command has completed.

       clCreateEventFromGLsyncKHR performs an implicit clRetainEvent(3clc) on the returned event
       object. Creating a linked event object also places a reference on the linked GL sync
       object. When the event object is deleted, the reference will be removed from the GL sync
       object.

       Events returned from clCreateEventFromGLsyncKHR may only be consumed by
       clEnqueueAcquireGLObjects(3clc). Passing such events to any other CL API will generate a
       CL_INVALID_EVENT error.

ERRORS

       Returns a valid OpenCL event object and errcode_ret is set to CL_SUCCESS if the event
       object is created successfully. Otherwise, it returns a NULL value with one of the
       following error values returned in errcode_ret:

       •   CL_INVALID_CONTEXT if context is not a valid context or was not created from a GL
           context.

       •   CL_INVALID_GL_OBJECT if sync is not the name of a sync object in the GL share group
           associated with context.

SPECIFICATION

       OpenCL Specification[1]

SEE ALSO

       cl_khr_gl_event(3clc), clEnqueueAcquireGLObjects(3clc), clRetainEvent(3clc)

AUTHORS

       The Khronos Group

COPYRIGHT

       Copyright © 2007-2011 The Khronos Group Inc.
       Permission is hereby granted, free of charge, to any person obtaining a copy of this
       software and/or associated documentation files (the "Materials"), to deal in the Materials
       without restriction, including without limitation the rights to use, copy, modify, merge,
       publish, distribute, sublicense, and/or sell copies of the Materials, and to permit
       persons to whom the Materials are furnished to do so, subject to the condition that this
       copyright notice and permission notice shall be included in all copies or substantial
       portions of the Materials.

NOTES

        1. OpenCL Specification
           page 62, section 9.8.4 - Additions to Chapter 5