question: protected void waitForShutdownSignal ( ) throws InterruptedException { if ( mutexWaiting == null ) mutexWaiting = new Object ( ) ; try { synchronized ( mutexWaiting ) { mutexWaiting . wait ( ) ; } } catch ( InterruptedException e ) { if ( ! shutdown ) throw e ; } }
target:  Causes the current thread to block until signalShutdown is called. This is used by WorkerThreads which are not actively polling the shutdown field.