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3rdparty/boost_1_81_0/libs/thread/example/mutex.cpp 978 Bytes
73ef4ff3   Hu Chunming   提交三方库
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  // Copyright (C) 2001-2003
  // William E. Kempf
  //
  //  Distributed under the Boost Software License, Version 1.0. (See accompanying
  //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  
  #include <boost/thread/mutex.hpp>
  #include <boost/thread/thread.hpp>
  #include <iostream>
  
  boost::mutex io_mutex; // The iostreams are not guaranteed to be thread-safe!
  
  class counter
  {
  public:
      counter() : count(0) { }
  
      int increment() {
          boost::unique_lock<boost::mutex> scoped_lock(mutex);
          return ++count;
      }
  
  private:
      boost::mutex mutex;
      int count;
  };
  
  counter c;
  
  void change_count()
  {
      int i = c.increment();
      boost::unique_lock<boost::mutex> scoped_lock(io_mutex);
      std::cout << "count == " << i << std::endl;
  }
  
  int main(int, char*[])
  {
      const int num_threads = 4;
      boost::thread_group thrds;
      for (int i=0; i < num_threads; ++i)
          thrds.create_thread(&change_count);
  
      thrds.join_all();
  
      return 0;
  }