ceph/src/boost/libs/thread/tutorial/counter.cpp

   1 // Copyright (C) 2001-2003
   2 // William E. Kempf
   3 //
   4 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #include <boost/thread/mutex.hpp>
   8 #include <boost/thread/thread.hpp>
   9 #include <iostream>
  10
  11 boost::mutex mutex;
  12 int counter=0;
  13
  14 void change_count()
  15 {
  16     boost::mutex::scoped_lock lock(mutex);
  17     int i = ++counter;
  18     std::cout << "count == " << i << std::endl;
  19 }
  20
  21 int main()
  22 {
  23     const int num_threads = 4;
  24     boost::thread_group thrds;
  25     for (int i=0; i < num_threads; ++i)
  26         thrds.create_thread(&change_count);
  27     thrds.join_all();
  28 }