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 change_count()14void change_count() 15 { 16 boost::mutex::scoped_lock lock(mutex); 17 int i = ++counter; 18 std::cout << "count == " << i << std::endl; 19 } 20 main()21int 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 } 29