• line 17: op(0, -1, SEM_UNDO) in place of setval(0, ($semval+1))
  • line 31: op(0,  1, SEM_UNDO) in place of setval(0, ($semval-1))

    Semaphores DECREMENT to lock, and INCREMENT to unlock.

    In reply to Re: Re^2: Effective use of IPC::Semaphore to limit number of concurrent executions of a scxipt by ptkdb
    in thread Effective use of IPC::Semaphore to limit number of concurrent executions of a scxipt by atcroft

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