ceph/src/common/Semaphore.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15
  16 #ifndef CEPH_Sem_Posix__H
  17 #define CEPH_Sem_Posix__H
  18
  19 #include "common/ceph_mutex.h"
  20
  21 class Semaphore
  22 {
  23   ceph::mutex m = ceph::make_mutex("Semaphore::m");
  24   ceph::condition_variable c;
  25   int count = 0;
  26
  27   public:
  28
  29   void Put()
  30   {
  31     std::lock_guard l(m);
  32     count++;
  33     c.notify_all();
  34   }
  35
  36   void Get()
  37   {
  38     std::unique_lock l(m);
  39     while(count <= 0) {
  40       c.wait(l);
  41     }
  42     count--;
  43   }
  44 };
  45
  46 #endif // !_Mutex_Posix_