Concurrency with Java Threads

1) basic "Notify Events" - can not be queued.
 - if no threads waiting, Notify() - does nothing..
2) If you need "NOTIFICATIONS" be queued, we need to go beyond Wait()/Notify()/NotifyAll()

     - a) Semaphore (without Buzy waiting..)
     - b) Cyclic Barrier
     - c) CountDown Latch

Wait() - Notify() NotifyAll()

Synchronized(Mutex)

Thread-Singalling
Thread-Yielding

"Volatile " - in Threads