Improve thread sync in release

when i try to run the following code in debug and release mode in VS2005. Every time I see a different output in the console and it doesn't seem like multithreading is achieved in release mode.

1. #include <boost/thread.hpp> 
2. #include <iostream> 
3.
4. void wait(int seconds) 
5. { 
6.   boost::this_thread::sleep(boost::posix_time::seconds(seconds)); 
7. } 
8. 
9. boost::mutex mutex; 
10. 
11. void thread() 
12. { 
13.  for (int i = 0; i < 5; ++i) 
14.  { 
15.    //wait(1);
16.    mutex.lock(); 
17.    std::cout << "Thread " << boost::this_thread::get_id() << ": " << i << std::endl; 
18.    mutex.unlock(); 
19.  } 
20. } 
21.
22. int main() 
23. { 
24.   boost::thread t1(thread); 
25.   boost::thread t2(thread); 
26.   t1.join(); 
27.   t2.join(); 
28. }

      

        
        
        
      

    

Debug mode

Thread 00153E60: 0
Thread 00153E90: 0
Thread 00153E60: 1
Thread 00153E90: 1
Thread 00153E90: 2
Thread 00153E60: 2
Thread 00153E90: 3
Thread 00153E60: 3
Thread 00153E60: 4
Thread 00153E90: 4
Press any key to continue . . .

      

        
        
        
      

    

Release mode

Thread 00153D28: 0
Thread 00153D28: 1
Thread 00153D28: 2
Thread 00153D28: 3
Thread 00153D28: 4
Thread 00153D58: 0
Thread 00153D58: 1
Thread 00153D58: 2
Thread 00153D58: 3
Thread 00153D58: 4
Press any key to continue . . .