This document discusses inter-thread communication in Java, which allows synchronized threads to communicate with each other. It describes polling as a wasteful process where a thread repeatedly checks a condition, and how inter-thread communication avoids this through wait(), notify(), and notifyAll() methods. These methods, defined in the Object class, allow one thread to pause while another thread executes, with notify() waking one thread and notifyAll() waking all threads. The key difference between wait() and sleep() is that wait() releases the monitor lock while sleeping.

1. INTER THREAD
COMMUNICATION

2. WHY IT IS REQUIRED ???
There are situations when one thread keeps on checking for
some condition repeatedly, once that condition satisfies the
thread moves ahead with its appropriate action. This situation is
known as POLLING.
This is basically a wastage of CPU time which is undesirable so,
to avoid polling, java has an elegant inter thread communication
mechanism.

3. WHAT IS IT ??
•Allowing synchronized threads to communicate
with each other.
•Cooperation is a mechanism in which a thread
is paused running in its critical section and
another thread is allowed to enter (or lock) in
the same critical section to be executed.

4. EXAMPLE :

6. HOW INTER THREAD COMMUNICATION IS
ACHIEVED ???
It is implemented by following methods
of Object class:
wait()
notify()
notifyAll()

7. UNDERSTANDING THE PROCESS OF INTER-
THREAD COMMUNICATION

8. WAIT() METHOD

9. NOTIFY() METHOD
Syntax :
public final void notify()

10. NOTIFYALL() METHOD
Syntax :
public final void notifyAll()

11. Why wait(), notify() and
notifyAll() methods are defined
in Object class not Thread
class ?

12. DIFFERENCE BETWEEN WAIT AND SLEEP ?

15. THANK YOU