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Text File  |  1988-12-29  |  588 b   |  25 lines
  1. Class  Semaphore :List
  2. | excessSignals |
  3.  
  4. [  new
  5.      excessSignals <- 0
  6.  
  7. |  new: aNumber
  8.      excessSignals <- aNumber
  9.  
  10. |  signal
  11.      <StartAtomic>. "start atomic action"
  12.      (self isEmpty)
  13.        ifTrue: [excessSignals <- excessSignals + 1]
  14.        ifFalse: [self removeFirst unblock].
  15.      <EndAtomic>         "end atomic action"
  16.  
  17. |  wait
  18.      <StartAtomic>. "start atomic actions"
  19.      (excessSignals = 0)
  20.        ifTrue: [self addLast: selfProcess.
  21.              selfProcess block]
  22.        ifFalse: [excessSignals <- excessSignals - 1].
  23.      <EndAtomic>         "end atomic actions"
  24. ]
  25.