Question

What would be the most elegant way to implement a Win32 equivalent of WaitForMultipleObjects in Java (v6). A thread is sleeping until one of several events occur. When that happens, I want to process it and get back to sleep. No data is required, just an event.

Answer 1

It really depends what you want to do with it, but you could do something as simple as using the wait/notify methods or you could use the structures in the java.util.concurrency package. The latter would personally be my choice. You could easily set up a BlockingQueue that you could have producers drop event objects into and consumers blocking on removing the events.

// somewhere out there
public enum Events {
  TERMINATE, DO_SOMETHING, BAKE_SOMETHING
}

// inside consumer
Events e;
while( (e = queue.take()) != TERMINATE ) {
  switch(e) {
    case DO_SOMETHING:
      // blah blah
  }
}

// somewhere else in another thread
Events e = BAKE_SOMETHING;
if( queue.offer(e) )
   // the queue gladly accepted our BAKE_SOMETHING event!
else
   // oops! we could block with put() if we want...