iokit/Kernel/IOService.cpp

983     ArbitrationLockQueueElement * waiting;
1028             // before placing this new thread on the waiting queue, we look for
1033                 // want is waiting for another object to be unlocked
1036                                waiting,
1040                     if( waiting->thread == active->thread ) {
1041                         assert( false == waiting->aborted );
1047                 if( found ) { // yes, active thread waiting for another object
1051                     if( false == waiting->required )
1052                         victim = waiting;
1062                         if( active->service == waiting->service ) {
1068                     // someone must be holding it or it wouldn't be waiting
1073                         // doh, it's waiting for the thread that originated
1084                             // see if we came across a waiting thread that did
1091                                 // take the victim off the waiting queue
1107                                 // all the waiting threads we came across in
1116                         // looking for threads waiting on it; note the active
1120                 } else { // no, active thread is not waiting for another object
1127             if( success ) { // put the request on the waiting queue?
1130                 // place this thread on the waiting queue and put it to sleep;
1145                 // put thread to sleep, waiting for our event to fire...
1154                 //     already been moved from the waiting queue to the
1157                 // (c) we're still on the waiting queue
1165                     // determine whether we're still on the waiting queue
1168                                    waiting,     // (reuse waiting queue element)
1172                         if( waiting == element ) {
1178                     if( found ) { // yes, we're still on the waiting queue
1186                             // take us off the waiting queue
1218                     // we've already been moved from waiting to active queue
1304         // determine whether a thread is waiting for object (head to tail scan)
1317         if ( found ) { // we found an interested thread on waiting queue
1319             // remove it from the waiting queue
1331             // wake the waiting thread