SCClassLibrary/Common/Core/Semaphore.sc

   1 Semaphore {
   2         var <count, waitingThreads;
   3
   4         *new { | count=1 |
   5                 ^super.newCopyArgs(count, LinkedList.new)
   6         }
   7         clear {
   8                 waitingThreads = LinkedList.new;
   9         }
  10         wait {
  11                 count = count - 1;
  12                 if (count < 0) {
  13                         waitingThreads.add(thisThread);
  14                         nil.yield;
  15                 };
  16         }
  17         signal {
  18                 var thread;
  19                 count = count + 1;
  20                 thread = waitingThreads.popFirst;
  21                 if (thread.notNil) {
  22                         thread.clock.sched(0, thread);
  23                 };
  24         }
  25 }