What sync object should i use?

[Sean Kelly]

I'm doing this from my phone so please bear with me.

You use a mutex in combination with a condition variable so you 
can check the state of something to determine if waiting is 
necessary. So the classic producer/consumer would be something 
like:

T get() {
     shnchronized(c.mutex) {
         while (q.isEmpty)
             c.wait();
         return q.take();
     }
}

void put(T val) {
     synchronized (c.mutex) {
         q.add(val);
         c.notify();
     }
}

You can emulate a Win32 event that stays flipped by 
checking/setting a bool or int inside the mutex.