Starting the message-dispatching execution thread

Starting the message-dispatching execution thread
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auto clinstance = myClass::create();

x::start_threadmsgdispatcher(clinstance);

x::start_threadmsgdispatcher must be used to start an execution thread for a subclass of x::threadmsgdispatcherObj. x::start_threadmsgdispatcher() is a wrapper for x::run(). The first parameter to the execution thread's run() message is a reference to an opaque mcguffin. Any remaining parameters to x::start_threadmsgdispatcher() get forwarded as additional parameters to the thread's run() method:

    void run(x::ptr<x::obj> &threadmsgdispatcher_mcguffin)
    {
        msgqueue_auto msgqueue(this);

        threadmsgdispatcher_mcguffin=nullptr;

        try {
            while (1)
                msgqueue.event();

        } catch (const x::stopexception &)
        {
        } catch (const x::exception &e)
        {
            LOG_ERROR(e);
            LOG_TRACE(e->backtrace);
        }
    }

The execution thread's run() method takes the following actions:

Constructs an instance of the msgqueue_auto class in automatic scope. msgqueue_auto gets inherited from x::threadmsgdispatcherObj. This represents the execution thread's message queue.
Performs any additional initialization steps.
Destroys the mcguffin by setting it to a nullptr.
Runs the main message dispatching loop by repeatedly invoking msgqueue_auto's event() method. The default behavior of event() is to wait for a message on the internal message queue, retrieve it, then invoke the private class method the message is for.

x::start_threadmsgdispatcher() does not return until the new execution thread destroys the mcguffin. This is why the mcguffin parameter gets passed to run() by reference, rather than value. This ensures that the new threads message queue exists after x::start_threadmsgdispatcher() returns.