question: private void decrementWorkerCount ( ) { for ( ; ; ) { int c = ctl . get ( ) ; if ( ctl . compareAndSet ( c , ctlOf ( runStateOf ( c ) , workerCountOf ( c ) - 1 ) ) ) break ; } }
target:  Decrements the workerCount field of ctl. This is called only on abrupt termination of a thread (see processWorkerExit). Other decrements are performed within getTask.