question: static boolean tryExternalUnpush ( ForkJoinTask < ? > t ) { ForkJoinPool p ; WorkQueue [ ] ws ; WorkQueue q ; Submitter z ; ForkJoinTask < ? > [ ] a ; int m , s ; if ( t != null && ( z = submitters . get ( ) ) != null && ( p = commonPool ) != null && ( ws = p . workQueues ) != null && ( m = ws . length - 1 ) >= 0 && ( q = ws [ m & z . seed & SQMASK ] ) != null && ( s = q . top ) != q . base && ( a = q . array ) != null ) { long j = ( ( ( a . length - 1 ) & ( s - 1 ) ) << ASHIFT ) + ABASE ; if ( U . getObject ( a , j ) == t && U . compareAndSwapInt ( q , QLOCK , 0 , 1 ) ) { if ( q . array == a && q . top == s && U . compareAndSwapObject ( a , j , t , null ) ) { q . top = s - 1 ; q . qlock = 0 ; return true ; } q . qlock = 0 ; } } return false ; }
target:  Tries to pop the given task from submitter's queue in common pool.