event reference count.
cl_int clRetainEvent(cl_event event)
Event object being retained.
The OpenCL commands that return an event perform an implicit retain.
CL_SUCCESS if the function executed successfully.
Otherwise, it returns one of the following errors:
eventis not a valid event object.
CL_OUT_OF_RESOURCESif there is a failure to allocate resources required by the OpenCL implementation on the device.
CL_OUT_OF_HOST_MEMORYif there is a failure to allocate resources required by the OpenCL implementation on the host.