I have the following code and it terminates as expected. When I call the destructor it interrupts the thread. But if I change the this_thread::sleep to this_thread::yield the join() never happens and the program hangs. I must be misunderstanding yield. But I really don't want a sleep if possible. Thanks, John MessageQueueHandler::~MessageQueueHandler() { // Terminate the thread pMessageQueueInputThread->interrupt(); pMessageQueueInputThread->join(); delete pMessageQueueInputThread; } void MessageQueueHandler::MessageQueueInputThread() { unsigned int receivedSize; unsigned int priority; char buffer[queueMaximumMessageSize]; boost::this_thread::interruption_enabled(); try { while(1) { // Process all messages in the queue while(inputMessageQueue->try_receive(buffer, queueMaximumMessageSize, receivedSize, priority)) { BaseMessage * msg = reinterpret_cast<BaseMessage*>(buffer); callbackTable->DispatchMessage(msg); boost::this_thread::interruption_point(); } // Give other threads a chance to run // This is also an interruption point boost::this_thread::sleep(boost::posix_time::millisec(50)); <==Here } } catch(boost::thread_interrupted const&) { return; } } ___________________________________ John Davies Contractor Home Respiratory Care Philips Home Healthcare Solutions 1740 Golden Mile Highway Monroeville, PA 15146 Email: john.davies@philips.com Fax: 724-387-4109 ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.