Win32: Shutdown the listeners before telling the accept threads to quit.

     */

 shutdown:

    /* Setting is_graceful will cause keep-alive connections to be closed

     * rather than block on the next network read.

    /* Setting is_graceful will cause threads handling keep-alive connections 

     * to close the connection after handling the current request.

     */

    is_graceful = 1;

    /* Setting shutdown_in_progress prevents new connections from

     * being accepted but allows the worker threads to continue

     * handling connections that have already been accepted.

    /* Close the listening sockets. Note, we must close the listeners

     * before closing any accept sockets pending in AcceptEx to prevent

     * memory leaks in the kernel.

     */

    shutdown_in_progress = 1;

    /* Close the listening sockets. */

    for (lr = ap_listeners; lr ; lr = lr->next) {

        apr_socket_close(lr->sd);

    }

    /* Shutdown listener threads and pending AcceptEx socksts 

     * but allow the worker threads to continue consuming from

     * the queue of accepted connections.

     */

    shutdown_in_progress = 1;

    Sleep(1000);

    /* Tell the worker threads to exit */