Чем отличаются функции sleep, wait и yield в контексте многопоточности?

In the context of multithreading in Java, the functions sleep, wait, and yield have different purposes:

• sleep(long millis):

  • Pauses the execution of the current thread for the specified time.
  • Does not release the monitor (lock) if it is held.
  • Used for delays.

• wait():

  • Causes the current thread to wait on an object, releasing the monitor of that object and entering the waiting state.
  • The thread will wait until another thread calls notify() or notifyAll() on the same object.
  • Used for inter-thread communication and synchronization.

• yield():

  • Suggests to the thread scheduler to give other threads of the same priority a chance to run.
  • The thread does not block or enter a waiting state; it simply pauses temporarily.
  • Used to improve scheduling but does not guarantee a switch.

Example:

Thread.sleep(1000); // pause for 1 second
synchronized(obj) {
    obj.wait(); // wait for notification
}
Thread.yield(); // suggest scheduler to switch