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
.
If there are enqueued commands with user events in the
event_wait_list
argument of
clEnqueue***
commands, the user 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); |