leader.c

apache的软件linux版本

        hold_off_on_exponential_spawning = 10;
    }

    ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
                "%s configured -- resuming normal operations",
                ap_get_server_version());
    ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf,
                "Server built: %s", ap_get_server_built());
#ifdef AP_MPM_WANT_SET_ACCEPT_LOCK_MECH
    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
		"AcceptMutex: %s (default: %s)",
		apr_proc_mutex_name(accept_mutex),
		apr_proc_mutex_defname());
#endif
    restart_pending = shutdown_pending = 0;
    mpm_state = AP_MPMQ_RUNNING;

    server_main_loop(remaining_children_to_start);
    mpm_state = AP_MPMQ_STOPPING;

    if (shutdown_pending) {
        /* Time to gracefully shut down:
         * Kill child processes, tell them to call child_exit, etc...
         * (By "gracefully" we don't mean graceful in the same sense as 
         * "apachectl graceful" where we allow old connections to finish.)
         */
	if (unixd_killpg(getpgrp(), SIGTERM) < 0) {
	    ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGTERM");
	}
        ap_reclaim_child_processes(1);                /* Start with SIGTERM */

        if (!child_fatal) {
            /* cleanup pid file on normal shutdown */
            const char *pidfile = NULL;
            pidfile = ap_server_root_relative (pconf, ap_pid_fname);
            if ( pidfile != NULL && unlink(pidfile) == 0)
                ap_log_error(APLOG_MARK, APLOG_INFO, 0,
                             ap_server_conf,
                             "removed PID file %s (pid=%ld)",
                             pidfile, (long)getpid());
    
            ap_log_error(APLOG_MARK, APLOG_NOTICE, 0,
                         ap_server_conf, "caught SIGTERM, shutting down");
        }
        return 1;
    }

    /* we've been told to restart */
    apr_signal(SIGHUP, SIG_IGN);

    if (one_process) {
        /* not worth thinking about */
        return 1;
    }

    /* advance to the next generation */
    /* XXX: we really need to make sure this new generation number isn't in
     * use by any of the children.
     */
    ++ap_my_generation;
    ap_scoreboard_image->global->running_generation = ap_my_generation;
    
    if (is_graceful) {
        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
                     AP_SIG_GRACEFUL_STRING " received.  Doing graceful restart");
        /* wake up the children...time to die.  But we'll have more soon */
        ap_mpm_pod_killpg(pod, ap_daemons_limit);
    

        /* This is mostly for debugging... so that we know what is still
         * gracefully dealing with existing request.
         */
        
    }
    else {
        /* Kill 'em all.  Since the child acts the same on the parents SIGTERM 
         * and a SIGHUP, we may as well use the same signal, because some user
         * pthreads are stealing signals from us left and right.
         */
        ap_mpm_pod_killpg(pod, ap_daemons_limit);

        ap_reclaim_child_processes(1);                /* Start with SIGTERM */
        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
                    "SIGHUP received.  Attempting to restart");
    }

    return 0;
}

/* This really should be a post_config hook, but the error log is already
 * redirected by that point, so we need to do this in the open_logs phase.
 */
static int leader_open_logs(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s)
{
    apr_status_t rv;

    pconf = p;
    ap_server_conf = s;

    if ((num_listensocks = ap_setup_listeners(ap_server_conf)) < 1) {
        ap_log_error(APLOG_MARK, APLOG_ALERT|APLOG_STARTUP, 0,
                     NULL, "no listening sockets available, shutting down");
        return DONE;
    }

    if (!one_process) {
        if ((rv = ap_mpm_pod_open(pconf, &pod))) {
            ap_log_error(APLOG_MARK, APLOG_CRIT|APLOG_STARTUP, rv, NULL,
                    "Could not open pipe-of-death.");
            return DONE;
        }
    }
    return OK;
}

static int leader_pre_config(apr_pool_t *pconf, apr_pool_t *plog, 
                             apr_pool_t *ptemp)
{
    static int restart_num = 0;
    int no_detach, debug, foreground;
    ap_directive_t *pdir;
    ap_directive_t *max_clients = NULL;
    apr_status_t rv;

    mpm_state = AP_MPMQ_STARTING;

    /* make sure that "ThreadsPerChild" gets set before "MaxClients" */
    for (pdir = ap_conftree; pdir != NULL; pdir = pdir->next) {
        if (strncasecmp(pdir->directive, "ThreadsPerChild", 15) == 0) {
            if (!max_clients) {
                break; /* we're in the clear, got ThreadsPerChild first */
            }
            else {
                /* now to swap the data */
                ap_directive_t temp;

                temp.directive = pdir->directive;
                temp.args = pdir->args;
                /* Make sure you don't change 'next', or you may get loops! */
                /* XXX: first_child, parent, and data can never be set
                 * for these directives, right? -aaron */
                temp.filename = pdir->filename;
                temp.line_num = pdir->line_num;

                pdir->directive = max_clients->directive;
                pdir->args = max_clients->args;
                pdir->filename = max_clients->filename;
                pdir->line_num = max_clients->line_num;
                
                max_clients->directive = temp.directive;
                max_clients->args = temp.args;
                max_clients->filename = temp.filename;
                max_clients->line_num = temp.line_num;
                break;
            }
        }
        else if (!max_clients
                 && strncasecmp(pdir->directive, "MaxClients", 10) == 0) {
            max_clients = pdir;
        }
    }

    debug = ap_exists_config_define("DEBUG");

    if (debug) {
        foreground = one_process = 1;
        no_detach = 0;
    }
    else {
        one_process = ap_exists_config_define("ONE_PROCESS");
        no_detach = ap_exists_config_define("NO_DETACH");
        foreground = ap_exists_config_define("FOREGROUND");
    }

    /* sigh, want this only the second time around */
    if (restart_num++ == 1) {
        is_graceful = 0;

        if (!one_process && !foreground) {
            rv = apr_proc_detach(no_detach ? APR_PROC_DETACH_FOREGROUND
                                           : APR_PROC_DETACH_DAEMONIZE);
            if (rv != APR_SUCCESS) {
                ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
                             "apr_proc_detach failed");
                return HTTP_INTERNAL_SERVER_ERROR;
            }
        }
        parent_pid = ap_my_pid = getpid();
    }

    unixd_pre_config(ptemp);
    ap_listen_pre_config();
    ap_daemons_to_start = DEFAULT_START_DAEMON;
    min_spare_threads = DEFAULT_MIN_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD;
    max_spare_threads = DEFAULT_MAX_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD;
    ap_daemons_limit = server_limit;
    ap_threads_per_child = DEFAULT_THREADS_PER_CHILD;
    ap_pid_fname = DEFAULT_PIDLOG;
    ap_lock_fname = DEFAULT_LOCKFILE;
    ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
    ap_extended_status = 0;
#ifdef AP_MPM_WANT_SET_MAX_MEM_FREE
	ap_max_mem_free = APR_ALLOCATOR_MAX_FREE_UNLIMITED;
#endif

    apr_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir));

    return OK;
}

static void leader_hooks(apr_pool_t *p)
{
    /* The leader open_logs phase must run before the core's, or stderr
     * will be redirected to a file, and the messages won't print to the
     * console.
     */
    static const char *const aszSucc[] = {"core.c", NULL};
    one_process = 0;

    ap_hook_open_logs(leader_open_logs, NULL, aszSucc, APR_HOOK_MIDDLE);
    /* we need to set the MPM state before other pre-config hooks use MPM query
     * to retrieve it, so register as REALLY_FIRST
     */
    ap_hook_pre_config(leader_pre_config, NULL, NULL, APR_HOOK_REALLY_FIRST);
}

static const char *set_daemons_to_start(cmd_parms *cmd, void *dummy,
                                        const char *arg) 
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    ap_daemons_to_start = atoi(arg);
    return NULL;
}

static const char *set_min_spare_threads(cmd_parms *cmd, void *dummy,
                                         const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    min_spare_threads = atoi(arg);
    if (min_spare_threads <= 0) {
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    "WARNING: detected MinSpareThreads set to non-positive.");
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    "Resetting to 1 to avoid almost certain Apache failure.");
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    "Please read the documentation.");
       min_spare_threads = 1;
    }
       
    return NULL;
}

static const char *set_max_spare_threads(cmd_parms *cmd, void *dummy,
                                         const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    max_spare_threads = atoi(arg);
    return NULL;
}

static const char *set_max_clients (cmd_parms *cmd, void *dummy,
                                     const char *arg) 
{
    int max_clients;
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    /* It is ok to use ap_threads_per_child here because we are
     * sure that it gets set before MaxClients in the pre_config stage. */
    max_clients = atoi(arg);
    if (max_clients < ap_threads_per_child) {
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    "WARNING: MaxClients (%d) must be at least as large",
                    max_clients);
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    " large as ThreadsPerChild (%d). Automatically",
                    ap_threads_per_child);
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    " increasing MaxClients to %d.",
                    ap_threads_per_child);
       max_clients = ap_threads_per_child;
    }
    ap_daemons_limit = max_clients / ap_threads_per_child;
    if ((max_clients > 0) && (max_clients % ap_threads_per_child)) {
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    "WARNING: MaxClients (%d) is not an integer multiple",
                    max_clients);
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    " of ThreadsPerChild (%d), lowering MaxClients to %d",
                    ap_threads_per_child,
                    ap_daemons_limit * ap_threads_per_child);
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    " for a maximum of %d child processes,",
                    ap_daemons_limit);
       max_clients = ap_daemons_limit * ap_threads_per_child; 
    }
    if (ap_daemons_limit > server_limit) {
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    "WARNING: MaxClients of %d would require %d servers,",
                    max_clients, ap_daemons_limit);
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    " and would exceed the ServerLimit value of %d.",
                    server_limit);
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    " Automatically lowering MaxClients to %d.  To increase,",
                    server_limit * ap_threads_per_child);
       ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                    " please see the ServerLimit directive.");
       ap_daemons_limit = server_limit;
    } 
    else if (ap_daemons_limit < 1) {
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                     "WARNING: Require MaxClients > 0, setting to 1");
        ap_daemons_limit = 1;
    }
    return NULL;
}

static const char *set_threads_per_child (cmd_parms *cmd, void *dummy,
                                          const char *arg) 
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    ap_threads_per_child = atoi(arg);
    if (ap_threads_per_child > thread_limit) {
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                     "WARNING: ThreadsPerChild of %d exceeds ThreadLimit "
                     "value of %d", ap_threads_per_child,
                     thread_limit);
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                     "threads, lowering ThreadsPerChild to %d. To increase, please"
                     " see the", thread_limit);
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                     " ThreadLimit directive.");
        ap_threads_per_child = thread_limit;
    }
    else if (ap_threads_per_child < 1) {
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, 
                     "WARNING: Require ThreadsPerChild > 0, setting to 1");
        ap_threads_per_child = 1;
    }
    return NULL;
}

static const char *set_server_limit (cmd_parms *cmd, void *dummy, const char *arg) 
{
    int tmp_server_limit;
    
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    tmp_server_limit = atoi(arg);
    /* you cannot change ServerLimit across a restart; ignore
     * any such attempts
     */
    if (first_server_limi