Question

I have my own threading library built using TinyThread++. It works quite well, and it was also a great learning experience for me. I have my own datastructures for passing around messages, and the interface makes good sense to me, primarily because I was its author.

Whenever a thread is created in my system, it runs in a loop, and checks for messages occasionally via a message passing protocol of my own devising.

Now I want to start using some Windows API functionality, and windows has its own set of conventions and message queues, etc. Now I’m pretty sure that TinyThread++ uses pthreads. Since I’m using MinGW, I’m wondering if pthreads is being implemented on windows threads. If this is the case, I may be able to just treat my pthreads-threads as windows-threads. But if not, I suspect I might run into some strange behavior.

edit: looking at the thread type given by Tinythread++ it looks like it actually uses the windows HANDLE to keep track of the threads and even uses _beginthreadex to spawn them.

My question is, will Windows be happy if I go around calling SetWindowsHookEx from some point in my pthreads code? I realize I need to have a Windows message polling loop in the same thread. I intend to do something like this:

try {

    HHOOK mousehook = SetWindowsHookEx(WH_MOUSE_LL, MouseHookProc,
        NULL, 0);
    if (mousehook == NULL) printf("Mousehook error %u\n",GetLastError());

    while(true) {
        MSG msg;
        if (GetMessage(&msg,0,0,0)) {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
    UnhookWindowsHookEx(mousehook);

    printf("Procedure completed without exceptional events.\n");

} catch (...) {
    printf("Exception!\n");
}

Answer 1

That should be fine.

You may run into trouble if you try to pass pthread thread ids to Windows threading functions which want a thread HANDLE, but here you just need the loop to stay in the same thread as SetWindowsHookEx.