Nonzero indicates success. Zero indicates failure. To get extended error information, call GetLastError.

For a manual-reset event object, all waiting threads that can be released immediately are released. The function then resets the event object's state to nonsignaled and returns.

For an auto-reset event object, the function resets the state to nonsignaled and returns after releasing a single waiting thread, even if multiple threads are waiting.

If no threads are waiting, or if no thread can be released immediately, PulseEvent simply sets the event object's state to nonsignaled and returns.

For a thread using the multiple-object wait functions to wait for all specified objects to be signaled, PulseEvent can set the event object's state to signaled and reset it to nonsignaled without causing the wait function to return. This happens if not all of the specified objects are simultaneously signaled.

Each object type, such as memory maps, semaphores, events, message queues, mutexes, and watchdog timers, has its own separate namespace. Empty strings, "", are handled as named objects. On Windows desktop-based platforms, synchronization objects all share the same namespace.

Reference