*From:* Boost-users [mailto:boost-users-bounces@lists.boost.org] *On Behalf Of *Riskybiz *Sent:* Thursday, July 18, 2013 5:55 PM *To:* boost-users@lists.boost.org *Subject:* [Boost-users] Boost::thread instantiation and clean up I have a C++ DLL written in Visual Studio for use on Windows 7 using Boost 1_53_0. The following two functions, CREATE & DESTROY, are called to launch and shutdown a simple ZeroMQ server (code below). The thread is launched and the server on that thread goes into a continuous listening loop (as intended). When it comes time to shut down the server then the thread is interrupted to cause thread termination (though I cannot tell if the interrupt is actually working as I get no output from the catch block). The boost::thread object is then deleted. Problem is that the 3rdparty application which this DLL is designed for is prone to crashing after DESTROY is called and I think it’s because either the boost::thread resources are not being freed/cleared up properly or the boost::thread is not interrupting. Have I properly handled thread instantiation, interruption and object destruction here? With thanks, Riskybiz. static bool createCalled = false;//initialise static variable static bool destroyCalled = false;//initialise static variable static boost::thread *serverThread = nullptr; int __stdcall CREATE() { if(createCalled == false) { createCalled = true; OutputDebugStringA("TestDataAccess: CREATE"); serverThread = new boost::thread(ListenOnReplySocket);//create instance of boost::thread object return 0; } return 1; } int __stdcall DESTROY() { if(createCalled == true && destroyCalled == false) { destroyCalled = true; OutputDebugStringA("TestDataAccess: DESTROY"); serverThread->interrupt();//set flag for interruption delete serverThread; return 0; } return 1; } Simple ZeroMQ server: #ifndef ZMQ_COMMUNICATIONS_H//if not defined already #define ZMQ_COMMUNICATIONS_H//then define it #define _WINSOCK2API_ //stops windows.h including winsock2.h #include <zmq.hpp> #include "boost\thread.hpp" int ListenOnReplySocket() { // Prepare our context and socket zmq::context_t context (1); zmq::socket_t socket (context, ZMQ_REP); socket.bind ("tcp://*:5555"); boost::this_thread::interruption_enabled(); try { while (true) { zmq::message_t request; // Wait for next request from client socket.recv (&request); char buffer[50]; int j; j = sprintf_s(buffer, 50, "TestDataAccess: ZMQComms: Hello"); OutputDebugStringA(buffer); // Do some 'work' Sleep (1000); // Send reply back to client zmq::message_t reply (5); memcpy ((void *) reply.data (), "World", 5); socket.send (reply); boost::this_thread::interruption_point();//check iterruption flag } } catch(boost::thread_interrupted) { char buffer[100]; int j; j = sprintf_s(buffer, 100, "TestDataAccess: ZMQComms: Server Thread Interrupted"); OutputDebugStringA(buffer); return 0; } } #endif ZMQ blocks on a .recv() call, so your thread may not be interrupting. Try looking at ZMQ’s poll option instead.