Why wait notify are in object class?
We wait on an object if we are waiting for some condition to change – some resource to become available. We notify on an object if we want to awaken sleeping threads. There can be any number of lock objects in your program – each locking a particular resource or code segment.
When to Use wait and notify in Java?
The wait() method causes the current thread to wait until another thread invokes the notify() or notifyAll() methods for that object. The notify() method wakes up a single thread that is waiting on that object’s monitor. The notifyAll() method wakes up all threads that are waiting on that object’s monitor.
What does the object wait () method do?
wait() causes current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object. In other words, this method behaves exactly as if it simply performs the call wait(0). The thread then waits until it can re-obtain ownership of the monitor and resumes execution. …
Why wait () notify () notifyAll () methods are in object class instead of thread class?
If wait() and notify() were on the Thread instead then each thread would have to know the status of every other thread and there is no way to know thread1 that thread2 was waiting for any resource to access. Hence, notify, wait, notifyAll methods are defined in object class in Java.
What is wait () notify ()?
Wait() notify() When wait() is called on a thread holding the monitor lock, it surrenders the monitor lock and enters the waiting state. When the notify() is called on a thread holding the monitor lock, it symbolizes that the thread is soon going to surrender the lock.
Can we override wait () or notify () methods?
Because of this, all Java classes inherit methods from Object . Object declares three versions of the wait method, as well as the methods notify , notifyAll and getClass . These methods all are final and cannot be overridden.