Where are variables stored in Java, Stack or Heap?

A primitive variable “holds” directly his value itself. Examples of a primitive variable :  int i, long l; A reference variable “holds” the reference (4 bytes on 32-bit JVMs, 8 bytes on 64-bit JVMs) who refers to an object. Examples of a reference variable : Student s, Date d; local variable...

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Why nonfair lock is faster than fair lock (java.util.concurrent.locks.Lock) in Java Concurrency

This is the nonfair scenario: When a thread B asks to hold a lock, if the lock is already taken by another thread A. Then the thread B will be suspended. After thread A finished his job, it releases the lock, then thread B is resumed. However, B needs a period of time to be able to actually run it's task from where it was suspended. And this period of time could be relatively long compared to another...

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