Hello. I'm designing a class with a locking policy. I have some code
that does exaclty this:


               if (cond) {
                       locking_policy_.lock();
                       out << message.message();
                       locking_policy_.unlock();
               }
               return *this;

And the lockingpolicy is a class like this one:

struct ThreadSafe {
       boost::mutex io_mutex_;
       boost::unique_lock<boost::mutex> lock_;

       ThreadSafe() : io_mutex_(), lock_(io_mutex_, boost::defer_lock) {}

       void lock() {
               std::cout << "Locking from " << boost::this_thread::get_id() << std::endl;
               lock_.lock();
       }

       void unlock() {
               std::cout << "Unlocking from " << boost::this_thread::get_id() << std::endl;
               lock_.unlock();
       }
};

Then, I create 3 threads and join them in the same order I created them:

boost::thread t1(&doSomething, "Hello1", boost::ref(logsink));
boost::thread t2(&doSomething, "Hello2", boost::ref(logsink));
boost::thread t3(&doSomehting, "Hello3", boost::ref(logsink));

       t1.join();
       t2.join();
       t3.join();

and I get a lock_error. Any help here, please? I can't figure out the problem.