Hi all, I have some problems with the boost::thread library, I've been staring at this code for a couple of days now but still have no idea what's wrong with it. The code starts a thread, the thread waits at a barrier, and command is transfered between the main thread and the new thread a couple of times (using two successive calls to barrier->wait() for each transition). This works fine most of the times, but sometimes the thread for some reason does not start. And when the main thread then waits at the barrier, the program obiously locks up. Here's the code: #include <iostream> #include #include class ThreadObject { public: boost::barrier *barrier; boost::thread *tacticsThread; ThreadObject() { barrier = new boost::barrier(2); std::cerr << "Main thread: Initiating ThreadObject\n"; tacticsThread = new boost::thread(*this); std::cerr << "Main thread: ThreadObject initiated\n"; } void operator()() { std::cerr << "Thread 2: Started\n"; // Waiting for the main thread to release this thread: barrier->wait(); std::cerr << "Thread 2: Processing.\n"; std::cerr << "Thread 2: Waiting for the main thread...\n"; // Release the main thread (which is waiting at the barrier): barrier->wait(); // Wait at the barrier until the main thread releases this thread again: barrier->wait(); std::cerr << "Thread 2: Continues.\n"; std::cerr << "Thread 2: Completed, now releasing the main thread.\n"; // Release the main thread (which is waiting at the barrier): barrier->wait(); } }; int main() { for (int i = 0; i < 100; i++) { std::cerr << std::endl << "Starting new test, i = " << i << std::endl; ThreadObject obj; std::cerr << "Main thread: Transferring command to Thread 2\n"; obj.barrier->wait(); obj.barrier->wait(); std::cerr << "Main thread: Command returned. Transfer command back to Thread 2 once more\n"; obj.barrier->wait(); obj.barrier->wait(); std::cerr << "Main thread: completed, everything ok\n"; } } In main(), a new ThreadObject is created, this will start a new thread. Then command is transfered back and forth a few times (with pairs of barrier->wait())). Since the code usually works fine, I've wrapped it all in a for loop, in order to repeat it multiple times. After a few iterations, the program locks up. The number of successful iterations before this happens varies, here is an example of output from a run which locked after two iterations: Starting new test, i = 0 Main thread: Initiating ThreadObject Main thread: ThreadObject initiated Main thread: Transferring command to Thread 2 Thread 2: Started Thread 2: Processing. Thread 2: Waiting for the main thread... Main thread: Command returned. Transfer command back to Thread 2 once more Thread 2: Continues. Thread 2: Completed, now releasing the main thread. Main thread: completed, everything ok Starting new test, i = 1 Main thread: Initiating ThreadObject Main thread: ThreadObject initiated Thread 2: Started Main thread: Transferring command to Thread 2 Thread 2: Processing. Thread 2: Waiting for the main thread... Main thread: Command returned. Transfer command back to Thread 2 once more Thread 2: Continues. Thread 2: Completed, now releasing the main thread. Main thread: completed, everything ok Starting new test, i = 2 Main thread: Initiating ThreadObject Main thread: ThreadObject initiated Main thread: Transferring command to Thread 2 So, why does not the new thread start up in the last test? Is there some problem with my code, or is there some bug in boost::thread? I'm compiling this using gcc-3.4.4 and boost 1.39.0 under cygwin. Thanks for any help, Henrik