TIOBE - Java Coding Standard

Rule: Design29

Synopsis:	Call Thread.notifyAll() rather than Thread.notify()
Language:	Java
Severity Level:	1
Category:	Design

Description:

Thread.notify() awakens a thread monitoring the object. If more than one thread is monitoring, then only one is chosen. The thread chosen is arbitrary; thus it's usually safer to call notifyAll() instead.

public class Foo {
 void bar() {
  x.notify();
  // If many threads are monitoring x, only one (and you won't know which) will be notified.
  // use instead:
  x.notifyAll();
 }
}