Understanding of Java Locks

The lock provides two main features: Mutex (mutual exclusion) and the Visibility (visibility) .

Mutual exclusion: Allows only one thread to hold a particular lock at a time, so you can use this attribute to implement a coordinated access protocol to shared data so that only one thread can use that shared data at a time.

Visibility: You must ensure that the changes made to the shared data before the lock is released are visible to the other thread that subsequently acquired the lock-if there is no guarantee of this visibility provided by the synchronization mechanism, the shared variables that the thread sees may be pre-modified or inconsistent values , which can cause many serious problems.

Understanding of Java Locks