I know that its a very lame question to ask experts like you but still i cannot help myself asking the question that "What is the Diffrence Between Notify & NotifyAll" method in the Object Class.
Well so far my search on the Internet reveals that 'notify()' method wakes up a single thread waiting on the object and passes the control of the monitor to it. So far so good and for 'notifyAll()' it says that its will wake up all the threads waiting on the object and will select a thread to pass control to it. Well as per me during that period the unselected thread will again go back to sleep in the JVM scheduler list and they will need yet another call to Notifty (or NotifyAll) in order to wake them up. So, as far as i see there is no diffrence between notify & notifyall as they both will result in waking up a single thread waiting on the Object.
If above assertions are indeed true than why to have two diffrent methods.
Thanks, Sathish Kumar.G
Certified on SCJP 5.0, OCPJWCD, Spring3.2, OCEJWSD
Satish: 'notifyAll()' it says that its will wake up all the threads waiting on the object and will select a thread to pass control to it
It is partly correct, notifyAll() will notify all the threads and after that all the threads will contest for the monitor lock. The thread that gets the monitor lock will start the work and the rest will be waiting for the monitor lock. The above difference is pretty big as the threads waiting for monitor will not require a notify() call to start processing but will start processing as soon as they get the monitor lock. If you take the thread dump and see the state of the threads (although getting this dump at the correct time is somewhat tough),
In case of notify() only one thread will get to the RUNNING state and other will be in WAIT state
In case of notifyAll() only one thread will get to the RUNNING state and other will be in BLOCKED state