Dispatch atleast one callback, blocking until the callback is dispatched.
CPG_DISPATCH_ALL
Dispatch all waiting callbacks without blocking to wait for any callbacks.
CPG_DISPATCH_BLOCKING
Dispatch all callbacks, blocking indefinitely. This is used in a threaded
program where a thread is created, and then cpg_dispatch() is called immediately
from the created thread to execute callbacks.
RETURN VALUE
This call returns the CPG_OK value if successful, otherwise an error is returned.