By contract, the method ``++Object.wait(...)++``, ``++Object.notify()++`` and ``++Object.notifyAll()++`` should be called by a thread that is the owner of the object's monitor. If this is not the case an ``++IllegalMonitorStateException++`` exception is thrown. This rule reinforces this constraint by making it mandatory to call one of these methods only inside a ``++synchronized++`` method or statement. == Noncompliant Code Example ---- private void removeElement() { while (!suitableCondition()){ obj.wait(); } ... // Perform removal } ---- or ---- private void removeElement() { while (!suitableCondition()){ wait(); } ... // Perform removal } ---- == Compliant Solution ---- private void removeElement() { synchronized(obj) { while (!suitableCondition()){ obj.wait(); } ... // Perform removal } } ---- or ---- private synchronized void removeElement() { while (!suitableCondition()){ wait(); } ... // Perform removal } ---- ifdef::env-github,rspecator-view[] ''' == Implementation Specification (visible only on this page) include::message.adoc[] endif::env-github,rspecator-view[]