event
A user event object created using clCreateUserEvent.
execution_status
Specifies the new execution status to be set and can be CL_COMPLETE or a negative integer value
to indicate an error. A negative integer value causes all enqueued commands that wait on this user event
to be terminated. clSetUserEventStatus
can only be called once to change the execution
status of event
.
Enqueued commands that specify user events in the event_wait_list
argument of
clEnqueue***
commands must ensure that the status of these user events being waited on are
set using clSetUserEventStatus
before any OpenCL APIs that release OpenCL objects except for
event objects are called; otherwise the behavior is undefined.
Returns CL_SUCCESS if the function was executed successfully. Otherwise, it returns one of the following errors
event
is not a valid user event.
execution_status
is not CL_COMPLETE
or a negative integer value.
execution_status
for
event
has already been changed by a previous call to
clSetUserEventStatus
.
For example, the following code sequence will result in undefined behavior of clReleaseMemObject.
ev1 = clCreateUserEvent(ctx, NULL); clEnqueueWriteBuffer(cq, buf1, CL_FALSE, ..., 1, &ev1, NULL; clEnqueueWriteBuffer(cq, buf2, CL_FALSE,...); clReleaseMemObject(buf2); clSetUserEventStatus(ev1, CL_COMPLETE); |
The following code sequence, however, works correctly.
ev1 = clCreateUserEvent(ctx, NULL); clEnqueueWriteBuffer(cq, buf1, CL_FALSE, ..., 1, &ev1, NULL; clEnqueueWriteBuffer(cq, buf2, CL_FALSE,...); clSetUserEventStatus(ev1, CL_COMPLETE); clReleaseMemObject(buf2); |