Wait() in Thread programming

Question

Please look at this method:
synchronized void doWhenCondition() {
while(!condition)
wait();
//Do what needs to be done when condition holds
A question that confuses me is: Suppose that all methods of this class are synchronized, and given that only one thread at a time can be executing any procedure of this class, is it still necessary to place condition waits in while loop?

Answer 1

A question that confuses me is: Suppose that all
methods of this class are synchronized, and given that
only one thread at a time can be executing any
procedure of this class, is it still necessary to
place condition waits in while loop? Even if you can determine that only one thread will be waiting, I would still always put wait() in a loop and use notifyAll() instead of notify(). The reason is that when the code is later modified, the assumption that only one thread will be waiting at one time may not be true, and you'll have a serious and hard-to-find bug in your code!
If you do determine that using notifyAll() is a performance problem, you can change it to notify(), but I would then add a big comment explaining that if the code is modified the notify() may need to be changed to notifyAll().