1.

What’s the difference between class lock and object lock?

Answer»

CLASS Lock: In java, each and every class has a UNIQUE lock usually referred to as a class level lock. These locks are achieved using the keyword ‘static synchronized’ and can be used to make static data thread-safe. It is generally used when ONE wants to prevent multiple threads from ENTERING a synchronized block. 

Example:  

PUBLIC class ClassLevelLockExample { public void classLevelLockMethod() { synchronized (ClassLevelLockExample.class) { //DO your stuff here } } }

Object Lock: In java, each and every object has a unique lock usually referred to as an object-level lock. These locks are achieved using the keyword ‘synchronized’ and can be used to protect non-static data. It is generally used when one wants to synchronize a non-static method or block so that only the thread will be able to execute the code block on a given instance of the class.  

Example:  

public class ObjectLevelLockExample { public void objectLevelLockMethod() { synchronized (this) { //DO your stuff here } }}


Discussion

No Comment Found

Related InterviewSolutions