Assume the following method is properly synchronized and called from a thread A on an object B:

wait(2000);

After calling this method, when will the thread A become a candidate to get another turn at the CPU?

  • After thread A is notified, or after two seconds.
  • After the lock on B is released, or after two seconds.
  • Two seconds after thread A is notified.
  • Two seconds after lock B is released.

Note/Explanation

Option A. Either of the two events (notification or wait time expiration) will make the thread become a candidate for running again.

Option B. is incorrect because a waiting thread will not return to runnable when the lock is released, unless a notification occurs.

Option C. is incorrect because the thread will become a candidate immediately after notification, not two seconds afterwards.

Option D. is also incorrect because a thread will not come out of a waiting pool just because a lock has been released.

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