question: public boolean shutdown ( long awaitTimeMillis ) { shutdown = true ; for ( GridWorker w : workers ) w . cancel ( ) ; while ( awaitTimeMillis > 0 && ! workers . isEmpty ( ) ) { try { Thread . sleep ( 100 ) ; awaitTimeMillis -= 100 ; } catch ( InterruptedException e ) { break ; } } return workers . isEmpty ( ) ; }
target:  Shuts down this executor service.