mpm_winnt.c

Apache 2.0.63 is the current stable version of the 2.0 series, and is recommended over any previous

    }

    /* Create the child_ready_event */
    waitlist[waitlist_ready] = CreateEvent(NULL, TRUE, FALSE, NULL);
    if (!waitlist[waitlist_ready]) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, apr_get_os_error(), ap_server_conf,
                     "Parent: Could not create ready event for child process");
        apr_pool_destroy (ptemp);
        return -1;
    }

    /* Create the child_exit_event */
    hExitEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
    if (!hExitEvent) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, apr_get_os_error(), ap_server_conf,
                     "Parent: Could not create exit event for child process");
        apr_pool_destroy(ptemp);
        CloseHandle(waitlist[waitlist_ready]);
        return -1;
    }

    if (!env) 
    {
        /* Build the env array, only once since it won't change 
         * for the lifetime of this parent process.
         */
        int envc;
        for (envc = 0; _environ[envc]; ++envc) {
            ;
        }
        env = malloc((envc + 2) * sizeof (char*));
        memcpy(env, _environ, envc * sizeof (char*));
        apr_snprintf(pidbuf, sizeof(pidbuf), "AP_PARENT_PID=%i", parent_pid);
        env[envc] = pidbuf;
        env[envc + 1] = NULL;
    }

    rv = apr_proc_create(&new_child, cmd, args, env, attr, ptemp);
    if (rv != APR_SUCCESS) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf,
                     "Parent: Failed to create the child process.");
        apr_pool_destroy(ptemp);
        CloseHandle(hExitEvent);
        CloseHandle(waitlist[waitlist_ready]);
        CloseHandle(new_child.hproc);
        return -1;
    }

    ap_log_error(APLOG_MARK, APLOG_NOTICE, APR_SUCCESS, ap_server_conf,
                 "Parent: Created child process %d", new_child.pid);

    if (send_handles_to_child(ptemp, waitlist[waitlist_ready], hExitEvent,
                              start_mutex, ap_scoreboard_shm,
                              new_child.hproc, new_child.in)) {
        /*
         * This error is fatal, mop up the child and move on
         * We toggle the child's exit event to cause this child 
         * to quit even as it is attempting to start.
         */
        SetEvent(hExitEvent);
        apr_pool_destroy(ptemp);
        CloseHandle(hExitEvent);
        CloseHandle(waitlist[waitlist_ready]);
        CloseHandle(new_child.hproc);
        return -1;
    }

    /* Important:
     * Give the child process a chance to run before dup'ing the sockets.
     * We have already set the listening sockets noninheritable, but if 
     * WSADuplicateSocket runs before the child process initializes
     * the listeners will be inherited anyway.
     */
    waitlist[waitlist_term] = new_child.hproc;
    rv = WaitForMultipleObjects(2, waitlist, FALSE, INFINITE);
    CloseHandle(waitlist[waitlist_ready]);
    if (rv != WAIT_OBJECT_0) {
        /* 
         * Outch... that isn't a ready signal. It's dead, Jim!
         */
        SetEvent(hExitEvent);
        apr_pool_destroy(ptemp);
        CloseHandle(hExitEvent);
        CloseHandle(new_child.hproc);
        return -1;
    }

    if (send_listeners_to_child(ptemp, new_child.pid, new_child.in)) {
        /*
         * This error is fatal, mop up the child and move on
         * We toggle the child's exit event to cause this child 
         * to quit even as it is attempting to start.
         */
        SetEvent(hExitEvent);
        apr_pool_destroy(ptemp);
        CloseHandle(hExitEvent);
        CloseHandle(new_child.hproc);
        return -1;
    }

    apr_file_close(new_child.in);

    *child_exit_event = hExitEvent;
    *child_proc = new_child.hproc;
    *child_pid = new_child.pid;

    return 0;
}

/***********************************************************************
 * master_main()
 * master_main() runs in the parent process.  It creates the child 
 * process which handles HTTP requests then waits on one of three 
 * events:
 *
 * restart_event
 * -------------
 * The restart event causes master_main to start a new child process and
 * tells the old child process to exit (by setting the child_exit_event).
 * The restart event is set as a result of one of the following:
 * 1. An apache -k restart command on the command line
 * 2. A command received from Windows service manager which gets 
 *    translated into an ap_signal_parent(SIGNAL_PARENT_RESTART)
 *    call by code in service.c.
 * 3. The child process calling ap_signal_parent(SIGNAL_PARENT_RESTART)
 *    as a result of hitting MaxRequestsPerChild.
 *
 * shutdown_event 
 * --------------
 * The shutdown event causes master_main to tell the child process to 
 * exit and that the server is shutting down. The shutdown event is
 * set as a result of one of the following:
 * 1. An apache -k shutdown command on the command line
 * 2. A command received from Windows service manager which gets
 *    translated into an ap_signal_parent(SIGNAL_PARENT_SHUTDOWN)
 *    call by code in service.c.
 *
 * child process handle
 * --------------------
 * The child process handle will be signaled if the child process 
 * exits for any reason. In a normal running server, the signaling
 * of this event means that the child process has exited prematurely
 * due to a seg fault or other irrecoverable error. For server
 * robustness, master_main will restart the child process under this 
 * condtion.
 *
 * master_main uses the child_exit_event to signal the child process
 * to exit.
 **********************************************************************/
#define NUM_WAIT_HANDLES 3
#define CHILD_HANDLE     0
#define SHUTDOWN_HANDLE  1
#define RESTART_HANDLE   2
static int master_main(server_rec *s, HANDLE shutdown_event, HANDLE restart_event)
{
    int rv, cld;
    int restart_pending;
    int shutdown_pending;
    HANDLE child_exit_event;
    HANDLE event_handles[NUM_WAIT_HANDLES];
    DWORD child_pid;

    restart_pending = shutdown_pending = 0;

    event_handles[SHUTDOWN_HANDLE] = shutdown_event;
    event_handles[RESTART_HANDLE] = restart_event;

    /* Create a single child process */
    rv = create_process(pconf, &event_handles[CHILD_HANDLE], 
                        &child_exit_event, &child_pid);
    if (rv < 0) 
    {
        ap_log_error(APLOG_MARK, APLOG_CRIT, apr_get_os_error(), ap_server_conf,
                     "master_main: create child process failed. Exiting.");
        shutdown_pending = 1;
        goto die_now;
    }
    if (!strcasecmp(signal_arg, "runservice")) {
        mpm_service_started();
    }

    /* Update the scoreboard. Note that there is only a single active
     * child at once.
     */
    ap_scoreboard_image->parent[0].quiescing = 0;
    ap_scoreboard_image->parent[0].pid = child_pid;

    /* Wait for shutdown or restart events or for child death */
    winnt_mpm_state = AP_MPMQ_RUNNING;
    rv = WaitForMultipleObjects(NUM_WAIT_HANDLES, (HANDLE *) event_handles, FALSE, INFINITE);
    cld = rv - WAIT_OBJECT_0;
    if (rv == WAIT_FAILED) {
        /* Something serious is wrong */
        ap_log_error(APLOG_MARK,APLOG_CRIT, apr_get_os_error(), ap_server_conf,
                     "master_main: WaitForMultipeObjects WAIT_FAILED -- doing server shutdown");
        shutdown_pending = 1;
    }
    else if (rv == WAIT_TIMEOUT) {
        /* Hey, this cannot happen */
        ap_log_error(APLOG_MARK, APLOG_ERR, apr_get_os_error(), s,
                     "master_main: WaitForMultipeObjects with INFINITE wait exited with WAIT_TIMEOUT");
        shutdown_pending = 1;
    }
    else if (cld == SHUTDOWN_HANDLE) {
        /* shutdown_event signalled */
        shutdown_pending = 1;
        ap_log_error(APLOG_MARK, APLOG_NOTICE, APR_SUCCESS, s, 
                     "Parent: Received shutdown signal -- Shutting down the server.");
        if (ResetEvent(shutdown_event) == 0) {
            ap_log_error(APLOG_MARK, APLOG_ERR, apr_get_os_error(), s,
                         "ResetEvent(shutdown_event)");
        }
    }
    else if (cld == RESTART_HANDLE) {
        /* Received a restart event. Prepare the restart_event to be reused 
         * then signal the child process to exit. 
         */
        restart_pending = 1;
        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, s, 
                     "Parent: Received restart signal -- Restarting the server.");
        if (ResetEvent(restart_event) == 0) {
            ap_log_error(APLOG_MARK, APLOG_ERR, apr_get_os_error(), s,
                         "Parent: ResetEvent(restart_event) failed.");
        }
        if (SetEvent(child_exit_event) == 0) {
            ap_log_error(APLOG_MARK, APLOG_ERR, apr_get_os_error(), s,
                         "Parent: SetEvent for child process %d failed.", 
                         event_handles[CHILD_HANDLE]);
        }
        /* Don't wait to verify that the child process really exits, 
         * just move on with the restart.
         */
        CloseHandle(event_handles[CHILD_HANDLE]);
        event_handles[CHILD_HANDLE] = NULL;
    }
    else {
        /* The child process exited prematurely due to a fatal error. */
        DWORD exitcode;
        if (!GetExitCodeProcess(event_handles[CHILD_HANDLE], &exitcode)) {
            /* HUH? We did exit, didn't we? */
            exitcode = APEXIT_CHILDFATAL;
        }
        if (   exitcode == APEXIT_CHILDFATAL 
            || exitcode == APEXIT_CHILDINIT
            || exitcode == APEXIT_INIT) {
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, 
                         "Parent: child process exited with status %u -- Aborting.", exitcode);
        }
        else {
            int i;
            restart_pending = 1;
            ap_log_error(APLOG_MARK, APLOG_NOTICE, APR_SUCCESS, ap_server_conf, 
                         "Parent: child process exited with status %u -- Restarting.", exitcode);
            for (i = 0; i < ap_threads_per_child; i++) {
                ap_update_child_status_from_indexes(0, i, SERVER_DEAD, NULL);
            }
        }
        CloseHandle(event_handles[CHILD_HANDLE]);
        event_handles[CHILD_HANDLE] = NULL;
    }
    if (restart_pending) {
        ++ap_my_generation;
        ap_scoreboard_image->global->running_generation = ap_my_generation;
    }
die_now:
    if (shutdown_pending) 
    {
        int timeout = 30000;  /* Timeout is milliseconds */
        winnt_mpm_state = AP_MPMQ_STOPPING;

        /* This shutdown is only marginally graceful. We will give the 
         * child a bit of time to exit gracefully. If the time expires,
         * the child will be wacked.
         */
        if (!strcasecmp(signal_arg, "runservice")) {
            mpm_service_stopping();
        }
        /* Signal the child processes to exit */
        if (SetEvent(child_exit_event) == 0) {
                ap_log_error(APLOG_MARK,APLOG_ERR, apr_get_os_error(), ap_server_conf,
                             "Parent: SetEvent for child process %d failed", event_handles[CHILD_HANDLE]);
        }
        if (event_handles[CHILD_HANDLE]) {
            rv = WaitForSingleObject(event_handles[CHILD_HANDLE], timeout);
            if (rv == WAIT_OBJECT_0) {
                ap_log_error(APLOG_MARK,APLOG_NOTICE, APR_SUCCESS, ap_server_conf,
                             "Parent: Child process exited successfully.");
                CloseHandle(event_handles[CHILD_HANDLE]);
                event_handles[CHILD_HANDLE] = NULL;
            }
            else {
                ap_log_error(APLOG_MARK,APLOG_NOTICE, APR_SUCCESS, ap_server_conf,
                             "Parent: Forcing termination of child process %d ", event_handles[CHILD_HANDLE]);
                TerminateProcess(event_handles[CHILD_HANDLE], 1);
                CloseHandle(event_handles[CHILD_HANDLE]);
                event_handles[CHILD_HANDLE] = NULL;
            }
        }
        CloseHandle(child_exit_event);
        return 0;  /* Tell the caller we do not want to restart */
    }
    winnt_mpm_state = AP_MPMQ_STARTING;
    CloseHandle(child_exit_event);
    return 1;      /* Tell the caller we want a restart */
}

/* service_nt_main_fn needs to append the StartService() args 
 * outside of our call stack and thread as the service starts...
 */
apr_array_header_t *mpm_new_argv;

/* Remember service_to_start failures to log and fail in pre_config.
 * Remember inst_argc and inst_argv for installing or starting the
 * service after we preflight the config.
 */

AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result)
{
    switch(query_code){
        case AP_MPMQ_MAX_DAEMON_USED:
            *result = MAXIMUM_WAIT_OBJECTS;
            return APR_SUCCESS;
        case AP_MPMQ_IS_THREADED:
            *result = AP_MPMQ_STATIC;
            return APR_SUCCESS;
        case AP_MPMQ_IS_FORKED:
            *result = AP_MPMQ_NOT_SUPPORTED;
            return APR_SUCCESS;
        case AP_MPMQ_HARD_LIMIT_DAEMONS:
            *result = HARD_SERVER_LIMIT;
            return APR_SUCCESS;
        case AP_MPMQ_HARD_LIMIT_THREADS:
            *result = thread_limit;
            return APR_SUCCESS;
        case AP_MPMQ_MAX_THREADS:
            *result = ap_threads_per_child;
            return APR_SUCCESS;
        case AP_MPMQ_MIN_SPARE_DAEMONS:
            *result = 0;
            return APR_SUCCESS;
        case AP_MPMQ_MIN_SPARE_THREADS:    
            *result = 0;
            return APR_SUCCESS;
        case AP_MPMQ_MAX_SPARE_DAEMONS:
            *result = 0;
            return APR_SUCCESS;
        case AP_MPMQ_MAX_SPARE_THREADS: