Happens Before Relationship in Java | Java Multi threading Interview Questions

What is happens before relationship in Java, this has been asked multiple times in Java Interviews.

A java candidate must be aware about Visibility, Ordering and Happens Before relationship. This shows candidate has knowledge about basics in Java Multi-threading.

Below are some of the topics that I have already covered. Check my channel for complete list of topics.

* Synchronization in Java

* Race conditions and Data Races in Java

* What is ideal thread pool size

*Thread Priority in Java

Let me know in the comment section if you have any question.

#java #javainterview @multithreading

[rapoliit]

Damn good man. Only nuances will make it to best videos.

[meriemasia]

Nice video, good luck in coming videos

[aakashbadola]

Hi Ajay,
Thanks for the video, but I have one doubt.. after applying synchronization on both methods I tried to test it again and again. But some times I get the following output:
Thread-0 has finished its job.
Thread 2 is printing the value of i: 0 the value should be 20000
I can see my first thread which is incrementing the value of "i" ran first and completed, then T2 ran and printed 0. I don't understand why this is happening, please help.
And can you please tell me the significance of using final Object reference in synchronized block rather than "this".

[darshgupta]

If you swap, t1.start() and t2.start() with each other in the example, it will again break.

[mrunalkubal]

Why to create new Object? Instead just pass this to synchronized block. synchronized (this)