1 /* ====================================================================
2 * The Apache Software License, Version 1.1
4 * Copyright (c) 2000-2002 The Apache Software Foundation. All rights
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
19 * 3. The end-user documentation included with the redistribution,
20 * if any, must include the following acknowledgment:
21 * "This product includes software developed by the
22 * Apache Software Foundation (http://www.apache.org/)."
23 * Alternately, this acknowledgment may appear in the software itself,
24 * if and wherever such third-party acknowledgments normally appear.
26 * 4. The names "Apache" and "Apache Software Foundation" must
27 * not be used to endorse or promote products derived from this
28 * software without prior written permission. For written
29 * permission, please contact apache@apache.org.
31 * 5. Products derived from this software may not be called "Apache",
32 * nor may "Apache" appear in their name, without prior written
33 * permission of the Apache Software Foundation.
35 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
36 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
37 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
38 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
42 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
43 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
44 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
45 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47 * ====================================================================
49 * This software consists of voluntary contributions made by many
50 * individuals on behalf of the Apache Software Foundation. For more
51 * information on the Apache Software Foundation, please see
52 * <http://www.apache.org/>.
54 * Portions of this software are based upon public domain software
55 * originally written at the National Center for Supercomputing Applications,
56 * University of Illinois, Urbana-Champaign.
59 /* The purpose of this MPM is to fix the design flaws in the threaded
60 * model. Because of the way that pthreads and mutex locks interact,
61 * it is basically impossible to cleanly gracefully shutdown a child
62 * process if multiple threads are all blocked in accept. This model
63 * fixes those problems.
67 #include "apr_portable.h"
68 #include "apr_strings.h"
69 #include "apr_file_io.h"
70 #include "apr_thread_proc.h"
71 #include "apr_signal.h"
72 #include "apr_thread_mutex.h"
73 #include "apr_proc_mutex.h"
74 #define APR_WANT_STRFUNC
80 #if APR_HAVE_SYS_SOCKET_H
81 #include <sys/socket.h>
83 #if APR_HAVE_SYS_WAIT_H
86 #ifdef HAVE_SYS_PROCESSOR_H
87 #include <sys/processor.h> /* for bindprocessor() */
91 #error The Worker MPM requires APR threads, but they are unavailable.
96 #include "ap_config.h"
98 #include "http_main.h"
100 #include "http_config.h" /* for read_config */
101 #include "http_core.h" /* for get_remote_host */
102 #include "http_connection.h"
105 #include "mpm_common.h"
106 #include "ap_listen.h"
107 #include "scoreboard.h"
109 #include "mpm_default.h"
112 #include <limits.h> /* for INT_MAX */
114 /* Limit on the total --- clients will be locked out if more servers than
115 * this are needed. It is intended solely to keep the server from crashing
116 * when things get out of hand.
118 * We keep a hard maximum number of servers, for two reasons --- first off,
119 * in case something goes seriously wrong, we want to stop the fork bomb
120 * short of actually crashing the machine we're running on by filling some
121 * kernel table. Secondly, it keeps the size of the scoreboard file small
122 * enough that we can read the whole thing without worrying too much about
125 #ifndef DEFAULT_SERVER_LIMIT
126 #define DEFAULT_SERVER_LIMIT 16
129 /* Admin can't tune ServerLimit beyond MAX_SERVER_LIMIT. We want
130 * some sort of compile-time limit to help catch typos.
132 #ifndef MAX_SERVER_LIMIT
133 #define MAX_SERVER_LIMIT 20000
136 /* Limit on the threads per process. Clients will be locked out if more than
137 * this * server_limit are needed.
139 * We keep this for one reason it keeps the size of the scoreboard file small
140 * enough that we can read the whole thing without worrying too much about
143 #ifndef DEFAULT_THREAD_LIMIT
144 #define DEFAULT_THREAD_LIMIT 64
147 /* Admin can't tune ThreadLimit beyond MAX_THREAD_LIMIT. We want
148 * some sort of compile-time limit to help catch typos.
150 #ifndef MAX_THREAD_LIMIT
151 #define MAX_THREAD_LIMIT 20000
155 * Actual definitions of config globals
158 int ap_threads_per_child = 0; /* Worker threads per child */
159 static int ap_daemons_to_start = 0;
160 static int min_spare_threads = 0;
161 static int max_spare_threads = 0;
162 static int ap_daemons_limit = 0;
163 static int server_limit = DEFAULT_SERVER_LIMIT;
164 static int first_server_limit;
165 static int thread_limit = DEFAULT_THREAD_LIMIT;
166 static int first_thread_limit;
167 static int changed_limit_at_restart;
168 static int dying = 0;
169 static int workers_may_exit = 0;
170 static int requests_this_child;
171 static int num_listensocks = 0;
172 static int resource_shortage = 0;
173 static fd_queue_t *worker_queue;
175 /* The structure used to pass unique initialization info to each thread */
182 /* Structure used to pass information to the thread responsible for
183 * creating the rest of the threads.
186 apr_thread_t **threads;
187 apr_thread_t *listener;
189 apr_threadattr_t *threadattr;
192 #define ID_FROM_CHILD_THREAD(c, t) ((c * thread_limit) + t)
195 * The max child slot ever assigned, preserved across restarts. Necessary
196 * to deal with MaxClients changes across AP_SIG_GRACEFUL restarts. We
197 * use this value to optimize routines that have to scan the entire
200 int ap_max_daemons_limit = -1;
202 static ap_pod_t *pod;
204 /* *Non*-shared http_main globals... */
206 server_rec *ap_server_conf;
208 /* The worker MPM respects a couple of runtime flags that can aid
209 * in debugging. Setting the -DNO_DETACH flag will prevent the root process
210 * from detaching from its controlling terminal. Additionally, setting
211 * the -DONE_PROCESS flag (which implies -DNO_DETACH) will get you the
212 * child_main loop running in the process which originally started up.
213 * This gives you a pretty nice debugging environment. (You'll get a SIGHUP
214 * early in standalone_main; just continue through. This is the server
215 * trying to kill off any child processes which it might have lying
216 * around --- Apache doesn't keep track of their pids, it just sends
217 * SIGHUP to the process group, ignoring it in the root process.
218 * Continue through and you'll be fine.).
221 static int one_process = 0;
224 int raise_sigstop_flags;
227 static apr_pool_t *pconf; /* Pool for config stuff */
228 static apr_pool_t *pchild; /* Pool for httpd child stuff */
230 static pid_t ap_my_pid; /* Linux getpid() doesn't work except in main
231 thread. Use this instead */
232 static pid_t parent_pid;
233 static apr_os_thread_t *listener_os_thread;
235 /* Locks for accept serialization */
236 static apr_proc_mutex_t *accept_mutex;
238 #ifdef SINGLE_LISTEN_UNSERIALIZED_ACCEPT
239 #define SAFE_ACCEPT(stmt) (ap_listeners->next ? (stmt) : APR_SUCCESS)
241 #define SAFE_ACCEPT(stmt) (stmt)
244 /* The LISTENER_SIGNAL signal will be sent from the main thread to the
245 * listener thread to wake it up for graceful termination (what a child
246 * process from an old generation does when the admin does "apachectl
247 * graceful"). This signal will be blocked in all threads of a child
248 * process except for the listener thread.
250 #define LISTENER_SIGNAL SIGHUP
252 static void wakeup_listener(void)
255 * we should just be able to "kill(ap_my_pid, LISTENER_SIGNAL)" and wake
256 * up the listener thread since it is the only thread with SIGHUP
257 * unblocked, but that doesn't work on Linux
259 pthread_kill(*listener_os_thread, LISTENER_SIGNAL);
262 static void signal_workers(void)
264 workers_may_exit = 1;
266 /* in case we weren't called from the listener thread, wake up the
271 /* XXX: This will happen naturally on a graceful, and we don't care
273 ap_queue_signal_all_wakeup(worker_queue); */
274 ap_queue_interrupt_all(worker_queue);
277 AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result)
280 case AP_MPMQ_MAX_DAEMON_USED:
281 *result = ap_max_daemons_limit;
283 case AP_MPMQ_IS_THREADED:
284 *result = AP_MPMQ_STATIC;
286 case AP_MPMQ_IS_FORKED:
287 *result = AP_MPMQ_DYNAMIC;
289 case AP_MPMQ_HARD_LIMIT_DAEMONS:
290 *result = server_limit;
292 case AP_MPMQ_HARD_LIMIT_THREADS:
293 *result = thread_limit;
295 case AP_MPMQ_MAX_THREADS:
296 *result = ap_threads_per_child;
298 case AP_MPMQ_MIN_SPARE_DAEMONS:
301 case AP_MPMQ_MIN_SPARE_THREADS:
302 *result = min_spare_threads;
304 case AP_MPMQ_MAX_SPARE_DAEMONS:
307 case AP_MPMQ_MAX_SPARE_THREADS:
308 *result = max_spare_threads;
310 case AP_MPMQ_MAX_REQUESTS_DAEMON:
311 *result = ap_max_requests_per_child;
313 case AP_MPMQ_MAX_DAEMONS:
314 *result = ap_daemons_limit;
320 /* a clean exit from a child with proper cleanup */
321 static void clean_child_exit(int code) __attribute__ ((noreturn));
322 static void clean_child_exit(int code)
325 apr_pool_destroy(pchild);
330 /* handle all varieties of core dumping signals */
331 static void sig_coredump(int sig)
333 apr_filepath_set(ap_coredump_dir, pconf);
334 apr_signal(sig, SIG_DFL);
335 if (ap_my_pid == parent_pid) {
336 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE,
338 "seg fault or similar nasty error detected "
339 "in the parent process");
341 /* XXX we can probably add some rudimentary cleanup code here,
342 * like getting rid of the pid file. If any additional bad stuff
343 * happens, we are protected from recursive errors taking down the
344 * system since this function is no longer the signal handler GLA
347 kill(ap_my_pid, sig);
348 /* At this point we've got sig blocked, because we're still inside
349 * the signal handler. When we leave the signal handler it will
350 * be unblocked, and we'll take the signal... and coredump or whatever
351 * is appropriate for this particular Unix. In addition the parent
352 * will see the real signal we received -- whereas if we called
353 * abort() here, the parent would only see SIGABRT.
357 static void just_die(int sig)
362 /*****************************************************************
363 * Connection structures and accounting...
366 /* volatile just in case */
367 static int volatile shutdown_pending;
368 static int volatile restart_pending;
369 static int volatile is_graceful;
370 static volatile int child_fatal;
371 ap_generation_t volatile ap_my_generation;
374 * ap_start_shutdown() and ap_start_restart(), below, are a first stab at
375 * functions to initiate shutdown or restart without relying on signals.
376 * Previously this was initiated in sig_term() and restart() signal handlers,
377 * but we want to be able to start a shutdown/restart from other sources --
378 * e.g. on Win32, from the service manager. Now the service manager can
379 * call ap_start_shutdown() or ap_start_restart() as appropiate. Note that
380 * these functions can also be called by the child processes, since global
381 * variables are no longer used to pass on the required action to the parent.
383 * These should only be called from the parent process itself, since the
384 * parent process will use the shutdown_pending and restart_pending variables
385 * to determine whether to shutdown or restart. The child process should
386 * call signal_parent() directly to tell the parent to die -- this will
387 * cause neither of those variable to be set, which the parent will
388 * assume means something serious is wrong (which it will be, for the
389 * child to force an exit) and so do an exit anyway.
392 static void ap_start_shutdown(void)
394 if (shutdown_pending == 1) {
395 /* Um, is this _probably_ not an error, if the user has
396 * tried to do a shutdown twice quickly, so we won't
397 * worry about reporting it.
401 shutdown_pending = 1;
404 /* do a graceful restart if graceful == 1 */
405 static void ap_start_restart(int graceful)
408 if (restart_pending == 1) {
409 /* Probably not an error - don't bother reporting it */
413 is_graceful = graceful;
415 apr_pool_cleanup_kill(pconf, NULL, ap_cleanup_scoreboard);
419 static void sig_term(int sig)
424 static void restart(int sig)
426 ap_start_restart(sig == AP_SIG_GRACEFUL);
429 static void set_signals(void)
431 #ifndef NO_USE_SIGACTION
434 sigemptyset(&sa.sa_mask);
438 sa.sa_handler = sig_coredump;
439 #if defined(SA_ONESHOT)
440 sa.sa_flags = SA_ONESHOT;
441 #elif defined(SA_RESETHAND)
442 sa.sa_flags = SA_RESETHAND;
444 if (sigaction(SIGSEGV, &sa, NULL) < 0)
445 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
446 "sigaction(SIGSEGV)");
448 if (sigaction(SIGBUS, &sa, NULL) < 0)
449 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
450 "sigaction(SIGBUS)");
453 if (sigaction(SIGABORT, &sa, NULL) < 0)
454 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
455 "sigaction(SIGABORT)");
458 if (sigaction(SIGABRT, &sa, NULL) < 0)
459 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
460 "sigaction(SIGABRT)");
463 if (sigaction(SIGILL, &sa, NULL) < 0)
464 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
465 "sigaction(SIGILL)");
469 sa.sa_handler = sig_term;
470 if (sigaction(SIGTERM, &sa, NULL) < 0)
471 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
472 "sigaction(SIGTERM)");
474 if (sigaction(SIGINT, &sa, NULL) < 0)
475 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
476 "sigaction(SIGINT)");
479 sa.sa_handler = SIG_DFL;
480 if (sigaction(SIGXCPU, &sa, NULL) < 0)
481 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
482 "sigaction(SIGXCPU)");
485 sa.sa_handler = SIG_DFL;
486 if (sigaction(SIGXFSZ, &sa, NULL) < 0)
487 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
488 "sigaction(SIGXFSZ)");
491 sa.sa_handler = SIG_IGN;
492 if (sigaction(SIGPIPE, &sa, NULL) < 0)
493 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
494 "sigaction(SIGPIPE)");
497 /* we want to ignore HUPs and AP_SIG_GRACEFUL while we're busy
499 sigaddset(&sa.sa_mask, SIGHUP);
500 sigaddset(&sa.sa_mask, AP_SIG_GRACEFUL);
501 sa.sa_handler = restart;
502 if (sigaction(SIGHUP, &sa, NULL) < 0)
503 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
504 "sigaction(SIGHUP)");
505 if (sigaction(AP_SIG_GRACEFUL, &sa, NULL) < 0)
506 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
507 "sigaction(" AP_SIG_GRACEFUL_STRING ")");
510 apr_signal(SIGSEGV, sig_coredump);
512 apr_signal(SIGBUS, sig_coredump);
515 apr_signal(SIGABORT, sig_coredump);
516 #endif /* SIGABORT */
518 apr_signal(SIGABRT, sig_coredump);
521 apr_signal(SIGILL, sig_coredump);
524 apr_signal(SIGXCPU, SIG_DFL);
527 apr_signal(SIGXFSZ, SIG_DFL);
531 apr_signal(SIGTERM, sig_term);
533 apr_signal(SIGHUP, restart);
535 #ifdef AP_SIG_GRACEFUL
536 apr_signal(AP_SIG_GRACEFUL, restart);
537 #endif /* AP_SIG_GRACEFUL */
539 apr_signal(SIGPIPE, SIG_IGN);
545 /*****************************************************************
546 * Here follows a long bunch of generic server bookkeeping stuff...
549 int ap_graceful_stop_signalled(void)
550 /* XXX this is really a bad confusing obsolete name
551 * maybe it should be ap_mpm_process_exiting?
554 return workers_may_exit;
557 /*****************************************************************
558 * Child process main loop.
561 static void process_socket(apr_pool_t *p, apr_socket_t *sock, int my_child_num,
564 conn_rec *current_conn;
565 long conn_id = ID_FROM_CHILD_THREAD(my_child_num, my_thread_num);
569 ap_create_sb_handle(&sbh, p, my_child_num, my_thread_num);
570 apr_os_sock_get(&csd, sock);
572 if (csd >= FD_SETSIZE) {
573 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, 0, NULL,
574 "new file descriptor %d is too large; you probably need "
575 "to rebuild Apache with a larger FD_SETSIZE "
578 apr_socket_close(sock);
582 current_conn = ap_run_create_connection(p, ap_server_conf, sock, conn_id, sbh);
584 ap_process_connection(current_conn, sock);
585 ap_lingering_close(current_conn);
589 /* requests_this_child has gone to zero or below. See if the admin coded
590 "MaxRequestsPerChild 0", and keep going in that case. Doing it this way
591 simplifies the hot path in worker_thread */
592 static void check_infinite_requests(void)
594 if (ap_max_requests_per_child) {
598 /* wow! if you're executing this code, you may have set a record.
599 * either this child process has served over 2 billion requests, or
600 * you're running a threaded 2.0 on a 16 bit machine.
602 * I'll buy pizza and beers at Apachecon for the first person to do
603 * the former without cheating (dorking with INT_MAX, or running with
604 * uncommitted performance patches, for example).
606 * for the latter case, you probably deserve a beer too. Greg Ames
609 requests_this_child = INT_MAX; /* keep going */
613 static void unblock_the_listener(int sig)
615 /* XXX If specifying SIG_IGN is guaranteed to unblock a syscall,
616 * then we don't need this goofy function.
620 static void *listener_thread(apr_thread_t *thd, void * dummy)
622 proc_info * ti = dummy;
623 int process_slot = ti->pid;
624 int thread_slot = ti->tid;
625 apr_pool_t *tpool = apr_thread_pool_get(thd);
627 apr_pool_t *ptrans; /* Pool for per-transaction stuff */
628 apr_pool_t *recycled_pool = NULL;
630 apr_pollfd_t *pollset;
632 ap_listen_rec *lr, *last_lr = ap_listeners;
638 apr_poll_setup(&pollset, num_listensocks, tpool);
639 for(lr = ap_listeners ; lr != NULL ; lr = lr->next)
640 apr_poll_socket_add(pollset, lr->sd, APR_POLLIN);
642 sigemptyset(&sig_mask);
643 /* Unblock the signal used to wake this thread up, and set a handler for
646 sigaddset(&sig_mask, LISTENER_SIGNAL);
647 #if defined(SIGPROCMASK_SETS_THREAD_MASK)
648 sigprocmask(SIG_UNBLOCK, &sig_mask, NULL);
650 pthread_sigmask(SIG_UNBLOCK, &sig_mask, NULL);
652 sigemptyset(&sa.sa_mask);
654 sa.sa_handler = unblock_the_listener;
655 sigaction(LISTENER_SIGNAL, &sa, NULL);
657 /* TODO: Switch to a system where threads reuse the results from earlier
658 poll calls - manoj */
660 /* TODO: requests_this_child should be synchronized - aaron */
661 if (requests_this_child <= 0) {
662 check_infinite_requests();
664 if (workers_may_exit) break;
666 if ((rv = SAFE_ACCEPT(apr_proc_mutex_lock(accept_mutex)))
668 int level = APLOG_EMERG;
670 if (workers_may_exit) {
673 if (ap_scoreboard_image->parent[process_slot].generation !=
674 ap_scoreboard_image->global->running_generation) {
675 level = APLOG_DEBUG; /* common to get these at restart time */
677 ap_log_error(APLOG_MARK, level, rv, ap_server_conf,
678 "apr_proc_mutex_lock failed. Attempting to shutdown "
679 "process gracefully.");
681 break; /* skip the lock release */
684 if (!ap_listeners->next) {
685 /* Only one listener, so skip the poll */
689 while (!workers_may_exit) {
693 ret = apr_poll(pollset, &n, -1);
694 if (ret != APR_SUCCESS) {
695 if (APR_STATUS_IS_EINTR(ret)) {
699 /* apr_poll() will only return errors in catastrophic
700 * circumstances. Let's try exiting gracefully, for now. */
701 ap_log_error(APLOG_MARK, APLOG_ERR, ret, (const server_rec *)
702 ap_server_conf, "apr_poll: (listen)");
706 if (workers_may_exit) break;
708 /* find a listener */
715 /* XXX: Should we check for POLLERR? */
716 apr_poll_revents_get(&event, lr->sd, pollset);
717 if (event & APR_POLLIN) {
721 } while (lr != last_lr);
725 if (!workers_may_exit) {
726 /* create a new transaction pool for each accepted socket */
727 if (recycled_pool == NULL) {
728 apr_allocator_t *allocator;
730 apr_allocator_create(&allocator);
731 apr_pool_create_ex(&ptrans, NULL, NULL, allocator);
732 apr_allocator_set_owner(allocator, ptrans);
735 ptrans = recycled_pool;
737 apr_pool_tag(ptrans, "transaction");
738 rv = lr->accept_func(&csd, lr, ptrans);
740 /* If we were interrupted for whatever reason, just start
741 * the main loop over again.
743 if (APR_STATUS_IS_EINTR(rv)) {
746 if (rv == APR_EGENERAL) {
747 /* E[NM]FILE, ENOMEM, etc */
748 resource_shortage = 1;
751 if ((rv = SAFE_ACCEPT(apr_proc_mutex_unlock(accept_mutex)))
753 int level = APLOG_EMERG;
755 if (workers_may_exit) {
758 if (ap_scoreboard_image->parent[process_slot].generation !=
759 ap_scoreboard_image->global->running_generation) {
760 level = APLOG_DEBUG; /* common to get these at restart time */
762 ap_log_error(APLOG_MARK, level, rv, ap_server_conf,
763 "apr_proc_mutex_unlock failed. Attempting to "
764 "shutdown process gracefully.");
768 rv = ap_queue_push(worker_queue, csd, ptrans,
771 /* trash the connection; we couldn't queue the connected
774 apr_socket_close(csd);
775 ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf,
776 "ap_queue_push failed");
781 if ((rv = SAFE_ACCEPT(apr_proc_mutex_unlock(accept_mutex)))
783 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
784 "apr_proc_mutex_unlock failed. Attempting to "
785 "shutdown process gracefully.");
792 ap_update_child_status_from_indexes(process_slot, thread_slot,
793 (dying) ? SERVER_DEAD : SERVER_GRACEFUL,
794 (request_rec *) NULL);
796 ap_scoreboard_image->parent[process_slot].quiescing = 1;
797 kill(ap_my_pid, SIGTERM);
799 apr_thread_exit(thd, APR_SUCCESS);
803 static void * APR_THREAD_FUNC worker_thread(apr_thread_t *thd, void * dummy)
805 proc_info * ti = dummy;
806 int process_slot = ti->pid;
807 int thread_slot = ti->tid;
808 apr_socket_t *csd = NULL;
809 apr_pool_t *last_ptrans = NULL;
810 apr_pool_t *ptrans; /* Pool for per-transaction stuff */
815 ap_update_child_status_from_indexes(process_slot, thread_slot, SERVER_STARTING, NULL);
816 while (!workers_may_exit) {
817 ap_update_child_status_from_indexes(process_slot, thread_slot, SERVER_READY, NULL);
818 rv = ap_queue_pop(worker_queue, &csd, &ptrans, last_ptrans);
821 /* We get APR_EINTR whenever ap_queue_pop() has been interrupted
822 * from an explicit call to ap_queue_interrupt_all(). This allows
823 * us to unblock threads stuck in ap_queue_pop() when a shutdown
825 if (rv == APR_EINTR || !csd) {
828 process_socket(ptrans, csd, process_slot, thread_slot);
829 requests_this_child--; /* FIXME: should be synchronized - aaron */
830 apr_pool_clear(ptrans);
831 last_ptrans = ptrans;
834 ap_update_child_status_from_indexes(process_slot, thread_slot,
835 (dying) ? SERVER_DEAD : SERVER_GRACEFUL, (request_rec *) NULL);
837 apr_thread_exit(thd, APR_SUCCESS);
841 static int check_signal(int signum)
851 /* XXX under some circumstances not understood, children can get stuck
852 * in start_threads forever trying to take over slots which will
853 * never be cleaned up; for now there is an APLOG_DEBUG message issued
854 * every so often when this condition occurs
856 static void * APR_THREAD_FUNC start_threads(apr_thread_t *thd, void *dummy)
858 thread_starter *ts = dummy;
859 apr_thread_t **threads = ts->threads;
860 apr_threadattr_t *thread_attr = ts->threadattr;
861 int child_num_arg = ts->child_num_arg;
862 int my_child_num = child_num_arg;
863 proc_info *my_info = NULL;
866 int threads_created = 0;
868 int prev_threads_created;
870 /* We must create the fd queues before we start up the listener
871 * and worker threads. */
872 worker_queue = apr_pcalloc(pchild, sizeof(*worker_queue));
873 rv = ap_queue_init(worker_queue, ap_threads_per_child, pchild);
874 if (rv != APR_SUCCESS) {
875 ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
876 "ap_queue_init() failed");
877 clean_child_exit(APEXIT_CHILDFATAL);
880 my_info = (proc_info *)malloc(sizeof(proc_info));
881 my_info->pid = my_child_num;
884 rv = apr_thread_create(&ts->listener, thread_attr, listener_thread,
886 if (rv != APR_SUCCESS) {
887 ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
888 "apr_thread_create: unable to create listener thread");
889 /* In case system resources are maxxed out, we don't want
890 * Apache running away with the CPU trying to fork over and
891 * over and over again if we exit.
892 * XXX Jeff doesn't see how Apache is going to try to fork again since
893 * the exit code is APEXIT_CHILDFATAL
895 apr_sleep(10 * APR_USEC_PER_SEC);
896 clean_child_exit(APEXIT_CHILDFATAL);
898 apr_os_thread_get(&listener_os_thread, ts->listener);
899 loops = prev_threads_created = 0;
901 /* ap_threads_per_child does not include the listener thread */
902 for (i = 0; i < ap_threads_per_child; i++) {
903 int status = ap_scoreboard_image->servers[child_num_arg][i].status;
905 if (status != SERVER_GRACEFUL && status != SERVER_DEAD) {
909 my_info = (proc_info *)malloc(sizeof(proc_info));
910 if (my_info == NULL) {
911 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf,
912 "malloc: out of memory");
913 clean_child_exit(APEXIT_CHILDFATAL);
915 my_info->pid = my_child_num;
919 /* We are creating threads right now */
920 ap_update_child_status_from_indexes(my_child_num, i,
921 SERVER_STARTING, NULL);
922 /* We let each thread update its own scoreboard entry. This is
923 * done because it lets us deal with tid better.
925 rv = apr_thread_create(&threads[i], thread_attr,
926 worker_thread, my_info, pchild);
927 if (rv != APR_SUCCESS) {
928 ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
929 "apr_thread_create: unable to create worker thread");
930 /* In case system resources are maxxed out, we don't want
931 Apache running away with the CPU trying to fork over and
932 over and over again if we exit. */
933 apr_sleep(10 * APR_USEC_PER_SEC);
934 clean_child_exit(APEXIT_CHILDFATAL);
938 if (workers_may_exit || threads_created == ap_threads_per_child) {
941 /* wait for previous generation to clean up an entry */
942 apr_sleep(1 * APR_USEC_PER_SEC);
944 if (loops % 120 == 0) { /* every couple of minutes */
945 if (prev_threads_created == threads_created) {
946 ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
947 "child %" APR_PID_T_FMT " isn't taking over "
948 "slots very quickly (%d of %d)",
949 ap_my_pid, threads_created, ap_threads_per_child);
951 prev_threads_created = threads_created;
955 /* What state should this child_main process be listed as in the
957 * ap_update_child_status_from_indexes(my_child_num, i, SERVER_STARTING,
958 * (request_rec *) NULL);
960 * This state should be listed separately in the scoreboard, in some kind
961 * of process_status, not mixed in with the worker threads' status.
962 * "life_status" is almost right, but it's in the worker's structure, and
963 * the name could be clearer. gla
965 apr_thread_exit(thd, APR_SUCCESS);
969 static void join_workers(apr_thread_t *listener, apr_thread_t **threads)
972 apr_status_t rv, thread_rv;
977 /* deal with a rare timing window which affects waking up the
978 * listener thread... if the signal sent to the listener thread
979 * is delivered between the time it verifies that the
980 * workers_may_exit flag is clear and the time it enters a
981 * blocking syscall, the signal didn't do any good... work around
982 * that by sleeping briefly and sending it again
986 while (iter < 10 && pthread_kill(*listener_os_thread, 0) == 0) {
987 /* listener not dead yet */
988 apr_sleep(APR_USEC_PER_SEC / 2);
993 ap_log_error(APLOG_MARK, APLOG_CRIT, 0, ap_server_conf,
994 "the listener thread didn't exit");
997 rv = apr_thread_join(&thread_rv, listener);
998 if (rv != APR_SUCCESS) {
999 ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf,
1000 "apr_thread_join: unable to join listener thread");
1005 for (i = 0; i < ap_threads_per_child; i++) {
1006 if (threads[i]) { /* if we ever created this thread */
1007 rv = apr_thread_join(&thread_rv, threads[i]);
1008 if (rv != APR_SUCCESS) {
1009 ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf,
1010 "apr_thread_join: unable to join worker "
1018 static void join_start_thread(apr_thread_t *start_thread_id)
1020 apr_status_t rv, thread_rv;
1022 workers_may_exit = 1; /* start thread may not want to exit until this
1025 rv = apr_thread_join(&thread_rv, start_thread_id);
1026 if (rv != APR_SUCCESS) {
1027 ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf,
1028 "apr_thread_join: unable to join the start "
1033 static void child_main(int child_num_arg)
1035 apr_thread_t **threads;
1038 apr_threadattr_t *thread_attr;
1039 apr_thread_t *start_thread_id;
1041 ap_my_pid = getpid();
1042 apr_pool_create(&pchild, pconf);
1044 /*stuff to do before we switch id's, so we have permissions.*/
1045 ap_reopen_scoreboard(pchild, NULL, 0);
1047 rv = SAFE_ACCEPT(apr_proc_mutex_child_init(&accept_mutex, ap_lock_fname,
1049 if (rv != APR_SUCCESS) {
1050 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
1051 "Couldn't initialize cross-process lock in child");
1052 clean_child_exit(APEXIT_CHILDFATAL);
1055 if (unixd_setup_child()) {
1056 clean_child_exit(APEXIT_CHILDFATAL);
1059 ap_run_child_init(pchild, ap_server_conf);
1061 /* done with init critical section */
1063 /* Just use the standard apr_setup_signal_thread to block all signals
1064 * from being received. The child processes no longer use signals for
1065 * any communication with the parent process.
1067 rv = apr_setup_signal_thread();
1068 if (rv != APR_SUCCESS) {
1069 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
1070 "Couldn't initialize signal thread");
1071 clean_child_exit(APEXIT_CHILDFATAL);
1074 if (ap_max_requests_per_child) {
1075 requests_this_child = ap_max_requests_per_child;
1078 /* coding a value of zero means infinity */
1079 requests_this_child = INT_MAX;
1082 /* Setup worker threads */
1084 /* clear the storage; we may not create all our threads immediately,
1085 * and we want a 0 entry to indicate a thread which was not created
1087 threads = (apr_thread_t **)calloc(1,
1088 sizeof(apr_thread_t *) * ap_threads_per_child);
1089 if (threads == NULL) {
1090 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf,
1091 "malloc: out of memory");
1092 clean_child_exit(APEXIT_CHILDFATAL);
1095 ts = (thread_starter *)apr_palloc(pchild, sizeof(*ts));
1097 apr_threadattr_create(&thread_attr, pchild);
1098 /* 0 means PTHREAD_CREATE_JOINABLE */
1099 apr_threadattr_detach_set(thread_attr, 0);
1101 ts->threads = threads;
1102 ts->listener = NULL;
1103 ts->child_num_arg = child_num_arg;
1104 ts->threadattr = thread_attr;
1106 rv = apr_thread_create(&start_thread_id, thread_attr, start_threads,
1108 if (rv != APR_SUCCESS) {
1109 ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
1110 "apr_thread_create: unable to create worker thread");
1111 /* In case system resources are maxxed out, we don't want
1112 Apache running away with the CPU trying to fork over and
1113 over and over again if we exit. */
1114 apr_sleep(10 * APR_USEC_PER_SEC);
1115 clean_child_exit(APEXIT_CHILDFATAL);
1118 /* If we are only running in one_process mode, we will want to
1119 * still handle signals. */
1121 /* Set up a signal handler for this thread. */
1122 apr_signal_thread(check_signal);
1123 /* make sure the start thread has finished; signal_workers()
1124 * and join_workers() depend on that
1126 join_start_thread(start_thread_id);
1127 signal_workers(); /* helps us terminate a little more quickly when
1128 * the dispatch of the signal thread
1129 * beats the Pipe of Death and the browsers
1131 /* A terminating signal was received. Now join each of the
1132 * workers to clean them up.
1133 * If the worker already exited, then the join frees
1134 * their resources and returns.
1135 * If the worker hasn't exited, then this blocks until
1136 * they have (then cleans up).
1138 join_workers(ts->listener, threads);
1140 else { /* !one_process */
1141 /* Watch for any messages from the parent over the POD */
1143 rv = ap_mpm_pod_check(pod);
1144 if (rv == AP_GRACEFUL || rv == AP_RESTART) {
1145 /* make sure the start thread has finished;
1146 * signal_workers() and join_workers depend on that
1148 join_start_thread(start_thread_id);
1154 if (rv == AP_GRACEFUL) {
1155 /* A terminating signal was received. Now join each of the
1156 * workers to clean them up.
1157 * If the worker already exited, then the join frees
1158 * their resources and returns.
1159 * If the worker hasn't exited, then this blocks until
1160 * they have (then cleans up).
1162 join_workers(ts->listener, threads);
1168 clean_child_exit(resource_shortage ? APEXIT_CHILDSICK : 0);
1171 static int make_child(server_rec *s, int slot)
1175 if (slot + 1 > ap_max_daemons_limit) {
1176 ap_max_daemons_limit = slot + 1;
1181 ap_scoreboard_image->parent[slot].pid = getpid();
1185 if ((pid = fork()) == -1) {
1186 ap_log_error(APLOG_MARK, APLOG_ERR, errno, s,
1187 "fork: Unable to fork new process");
1189 /* fork didn't succeed. Fix the scoreboard or else
1190 * it will say SERVER_STARTING forever and ever
1192 ap_update_child_status_from_indexes(slot, 0, SERVER_DEAD, NULL);
1194 /* In case system resources are maxxed out, we don't want
1195 Apache running away with the CPU trying to fork over and
1196 over and over again. */
1197 apr_sleep(10 * APR_USEC_PER_SEC);
1203 #ifdef HAVE_BINDPROCESSOR
1204 /* By default, AIX binds to a single processor. This bit unbinds
1205 * children which will then bind to another CPU.
1207 int status = bindprocessor(BINDPROCESS, (int)getpid(),
1208 PROCESSOR_CLASS_ANY);
1210 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, errno,
1212 "processor unbind failed %d", status);
1214 RAISE_SIGSTOP(MAKE_CHILD);
1216 apr_signal(SIGTERM, just_die);
1219 clean_child_exit(0);
1222 ap_scoreboard_image->parent[slot].quiescing = 0;
1223 ap_scoreboard_image->parent[slot].pid = pid;
1227 /* start up a bunch of children */
1228 static void startup_children(int number_to_start)
1232 for (i = 0; number_to_start && i < ap_daemons_limit; ++i) {
1233 if (ap_scoreboard_image->parent[i].pid != 0) {
1236 if (make_child(ap_server_conf, i) < 0) {
1245 * idle_spawn_rate is the number of children that will be spawned on the
1246 * next maintenance cycle if there aren't enough idle servers. It is
1247 * doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by
1248 * without the need to spawn.
1250 static int idle_spawn_rate = 1;
1251 #ifndef MAX_SPAWN_RATE
1252 #define MAX_SPAWN_RATE (32)
1254 static int hold_off_on_exponential_spawning;
1256 static void perform_idle_server_maintenance(void)
1259 int idle_thread_count;
1263 int totally_free_length = 0;
1264 int free_slots[MAX_SPAWN_RATE];
1268 /* initialize the free_list */
1271 idle_thread_count = 0;
1275 ap_sync_scoreboard_image();
1276 for (i = 0; i < ap_daemons_limit; ++i) {
1277 /* Initialization to satisfy the compiler. It doesn't know
1278 * that ap_threads_per_child is always > 0 */
1279 int status = SERVER_DEAD;
1280 int any_dying_threads = 0;
1281 int any_dead_threads = 0;
1282 int all_dead_threads = 1;
1284 if (i >= ap_max_daemons_limit && totally_free_length == idle_spawn_rate)
1286 ps = &ap_scoreboard_image->parent[i];
1287 for (j = 0; j < ap_threads_per_child; j++) {
1288 ws = &ap_scoreboard_image->servers[i][j];
1289 status = ws->status;
1291 /* XXX any_dying_threads is probably no longer needed GLA */
1292 any_dying_threads = any_dying_threads ||
1293 (status == SERVER_GRACEFUL);
1294 any_dead_threads = any_dead_threads || (status == SERVER_DEAD);
1295 all_dead_threads = all_dead_threads &&
1296 (status == SERVER_DEAD ||
1297 status == SERVER_GRACEFUL);
1299 /* We consider a starting server as idle because we started it
1300 * at least a cycle ago, and if it still hasn't finished starting
1301 * then we're just going to swamp things worse by forking more.
1302 * So we hopefully won't need to fork more if we count it.
1303 * This depends on the ordering of SERVER_READY and SERVER_STARTING.
1305 if (status <= SERVER_READY && status != SERVER_DEAD &&
1307 ps->generation == ap_my_generation &&
1308 /* XXX the following shouldn't be necessary if we clean up
1309 * properly after seg faults, but we're not yet GLA
1312 ++idle_thread_count;
1315 if (any_dead_threads && totally_free_length < idle_spawn_rate
1316 && (!ps->pid /* no process in the slot */
1317 || ps->quiescing)) { /* or at least one is going away */
1318 if (all_dead_threads) {
1319 /* great! we prefer these, because the new process can
1320 * start more threads sooner. So prioritize this slot
1321 * by putting it ahead of any slots with active threads.
1323 * first, make room by moving a slot that's potentially still
1324 * in use to the end of the array
1326 free_slots[free_length] = free_slots[totally_free_length];
1327 free_slots[totally_free_length++] = i;
1330 /* slot is still in use - back of the bus
1332 free_slots[free_length] = i;
1336 /* XXX if (!ps->quiescing) is probably more reliable GLA */
1337 if (!any_dying_threads) {
1342 ap_max_daemons_limit = last_non_dead + 1;
1344 if (idle_thread_count > max_spare_threads) {
1345 /* Kill off one child */
1346 ap_mpm_pod_signal(pod, TRUE);
1347 idle_spawn_rate = 1;
1349 else if (idle_thread_count < min_spare_threads) {
1350 /* terminate the free list */
1351 if (free_length == 0) {
1352 /* only report this condition once */
1353 static int reported = 0;
1356 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, 0,
1358 "server reached MaxClients setting, consider"
1359 " raising the MaxClients setting");
1362 idle_spawn_rate = 1;
1365 if (free_length > idle_spawn_rate) {
1366 free_length = idle_spawn_rate;
1368 if (idle_spawn_rate >= 8) {
1369 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0,
1371 "server seems busy, (you may need "
1372 "to increase StartServers, ThreadsPerChild "
1373 "or Min/MaxSpareThreads), "
1374 "spawning %d children, there are around %d idle "
1375 "threads, and %d total children", free_length,
1376 idle_thread_count, total_non_dead);
1378 for (i = 0; i < free_length; ++i) {
1379 make_child(ap_server_conf, free_slots[i]);
1381 /* the next time around we want to spawn twice as many if this
1382 * wasn't good enough, but not if we've just done a graceful
1384 if (hold_off_on_exponential_spawning) {
1385 --hold_off_on_exponential_spawning;
1387 else if (idle_spawn_rate < MAX_SPAWN_RATE) {
1388 idle_spawn_rate *= 2;
1393 idle_spawn_rate = 1;
1397 static void server_main_loop(int remaining_children_to_start)
1400 apr_exit_why_e exitwhy;
1401 int status, processed_status;
1405 while (!restart_pending && !shutdown_pending) {
1406 ap_wait_or_timeout(&exitwhy, &status, &pid, pconf);
1408 if (pid.pid != -1) {
1409 processed_status = ap_process_child_status(&pid, exitwhy, status);
1410 if (processed_status == APEXIT_CHILDFATAL) {
1411 shutdown_pending = 1;
1415 /* non-fatal death... note that it's gone in the scoreboard. */
1416 child_slot = find_child_by_pid(&pid);
1417 if (child_slot >= 0) {
1418 for (i = 0; i < ap_threads_per_child; i++)
1419 ap_update_child_status_from_indexes(child_slot, i, SERVER_DEAD,
1420 (request_rec *) NULL);
1422 ap_scoreboard_image->parent[child_slot].pid = 0;
1423 ap_scoreboard_image->parent[child_slot].quiescing = 0;
1424 if (processed_status == APEXIT_CHILDSICK) {
1425 /* resource shortage, minimize the fork rate */
1426 idle_spawn_rate = 1;
1428 else if (remaining_children_to_start
1429 && child_slot < ap_daemons_limit) {
1430 /* we're still doing a 1-for-1 replacement of dead
1431 * children with new children
1433 make_child(ap_server_conf, child_slot);
1434 --remaining_children_to_start;
1436 #if APR_HAS_OTHER_CHILD
1438 else if (apr_proc_other_child_read(&pid, status) == 0) {
1442 else if (is_graceful) {
1443 /* Great, we've probably just lost a slot in the
1444 * scoreboard. Somehow we don't know about this child.
1446 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, 0,
1448 "long lost child came home! (pid %ld)",
1451 /* Don't perform idle maintenance when a child dies,
1452 * only do it when there's a timeout. Remember only a
1453 * finite number of children can die, and it's pretty
1454 * pathological for a lot to die suddenly.
1458 else if (remaining_children_to_start) {
1459 /* we hit a 1 second timeout in which none of the previous
1460 * generation of children needed to be reaped... so assume
1461 * they're all done, and pick up the slack if any is left.
1463 startup_children(remaining_children_to_start);
1464 remaining_children_to_start = 0;
1465 /* In any event we really shouldn't do the code below because
1466 * few of the servers we just started are in the IDLE state
1467 * yet, so we'd mistakenly create an extra server.
1472 perform_idle_server_maintenance();
1476 int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s)
1478 int remaining_children_to_start;
1481 ap_log_pid(pconf, ap_pid_fname);
1483 first_server_limit = server_limit;
1484 first_thread_limit = thread_limit;
1485 if (changed_limit_at_restart) {
1486 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_NOERRNO, 0, s,
1487 "WARNING: Attempt to change ServerLimit or ThreadLimit "
1488 "ignored during restart");
1489 changed_limit_at_restart = 0;
1492 /* Initialize cross-process accept lock */
1493 ap_lock_fname = apr_psprintf(_pconf, "%s.%" APR_PID_T_FMT,
1494 ap_server_root_relative(_pconf, ap_lock_fname),
1497 rv = apr_proc_mutex_create(&accept_mutex, ap_lock_fname,
1498 ap_accept_lock_mech, _pconf);
1499 if (rv != APR_SUCCESS) {
1500 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s,
1501 "Couldn't create accept lock");
1505 #if APR_USE_SYSVSEM_SERIALIZE
1506 if (ap_accept_lock_mech == APR_LOCK_DEFAULT ||
1507 ap_accept_lock_mech == APR_LOCK_SYSVSEM) {
1509 if (ap_accept_lock_mech == APR_LOCK_SYSVSEM) {
1511 rv = unixd_set_proc_mutex_perms(accept_mutex);
1512 if (rv != APR_SUCCESS) {
1513 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s,
1514 "Couldn't set permissions on cross-process lock");
1520 if (ap_run_pre_mpm(s->process->pool, SB_SHARED) != OK) {
1523 /* fix the generation number in the global score; we just got a new,
1524 * cleared scoreboard
1526 ap_scoreboard_image->global->running_generation = ap_my_generation;
1527 update_scoreboard_global();
1531 /* Don't thrash... */
1532 if (max_spare_threads < min_spare_threads + ap_threads_per_child)
1533 max_spare_threads = min_spare_threads + ap_threads_per_child;
1535 /* If we're doing a graceful_restart then we're going to see a lot
1536 * of children exiting immediately when we get into the main loop
1537 * below (because we just sent them AP_SIG_GRACEFUL). This happens pretty
1538 * rapidly... and for each one that exits we'll start a new one until
1539 * we reach at least daemons_min_free. But we may be permitted to
1540 * start more than that, so we'll just keep track of how many we're
1541 * supposed to start up without the 1 second penalty between each fork.
1543 remaining_children_to_start = ap_daemons_to_start;
1544 if (remaining_children_to_start > ap_daemons_limit) {
1545 remaining_children_to_start = ap_daemons_limit;
1548 startup_children(remaining_children_to_start);
1549 remaining_children_to_start = 0;
1552 /* give the system some time to recover before kicking into
1553 * exponential mode */
1554 hold_off_on_exponential_spawning = 10;
1557 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,
1558 "%s configured -- resuming normal operations",
1559 ap_get_server_version());
1560 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0, ap_server_conf,
1561 "Server built: %s", ap_get_server_built());
1562 #ifdef AP_MPM_WANT_SET_ACCEPT_LOCK_MECH
1563 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,
1564 "AcceptMutex: %s", ap_mpm_show_accept_lock_mech());
1566 restart_pending = shutdown_pending = 0;
1568 server_main_loop(remaining_children_to_start);
1570 if (shutdown_pending) {
1571 /* Time to gracefully shut down:
1572 * Kill child processes, tell them to call child_exit, etc...
1573 * (By "gracefully" we don't mean graceful in the same sense as
1574 * "apachectl graceful" where we allow old connections to finish.)
1576 ap_mpm_pod_killpg(pod, ap_daemons_limit, FALSE);
1577 ap_reclaim_child_processes(1); /* Start with SIGTERM */
1580 /* cleanup pid file on normal shutdown */
1581 const char *pidfile = NULL;
1582 pidfile = ap_server_root_relative (pconf, ap_pid_fname);
1583 if ( pidfile != NULL && unlink(pidfile) == 0)
1584 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0,
1586 "removed PID file %s (pid=%ld)",
1587 pidfile, (long)getpid());
1589 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0,
1590 ap_server_conf, "caught SIGTERM, shutting down");
1595 /* we've been told to restart */
1596 apr_signal(SIGHUP, SIG_IGN);
1599 /* not worth thinking about */
1603 /* advance to the next generation */
1604 /* XXX: we really need to make sure this new generation number isn't in
1605 * use by any of the children.
1608 ap_scoreboard_image->global->running_generation = ap_my_generation;
1609 update_scoreboard_global();
1612 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,
1613 AP_SIG_GRACEFUL_STRING " received. Doing graceful restart");
1614 /* wake up the children...time to die. But we'll have more soon */
1615 ap_mpm_pod_killpg(pod, ap_daemons_limit, TRUE);
1618 /* This is mostly for debugging... so that we know what is still
1619 * gracefully dealing with existing request.
1624 /* Kill 'em all. Since the child acts the same on the parents SIGTERM
1625 * and a SIGHUP, we may as well use the same signal, because some user
1626 * pthreads are stealing signals from us left and right.
1628 ap_mpm_pod_killpg(pod, ap_daemons_limit, FALSE);
1630 ap_reclaim_child_processes(1); /* Start with SIGTERM */
1631 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,
1632 "SIGHUP received. Attempting to restart");
1638 /* This really should be a post_config hook, but the error log is already
1639 * redirected by that point, so we need to do this in the open_logs phase.
1641 static int worker_open_logs(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s)
1648 if ((num_listensocks = ap_setup_listeners(ap_server_conf)) < 1) {
1649 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ALERT|APLOG_STARTUP, 0,
1650 NULL, "no listening sockets available, shutting down");
1655 if ((rv = ap_mpm_pod_open(pconf, &pod))) {
1656 ap_log_error(APLOG_MARK, APLOG_CRIT|APLOG_STARTUP, rv, NULL,
1657 "Could not open pipe-of-death.");
1664 static int worker_pre_config(apr_pool_t *pconf, apr_pool_t *plog,
1667 static int restart_num = 0;
1668 int no_detach, debug;
1669 ap_directive_t *pdir;
1670 ap_directive_t *max_clients = NULL;
1673 /* make sure that "ThreadsPerChild" gets set before "MaxClients" */
1674 for (pdir = ap_conftree; pdir != NULL; pdir = pdir->next) {
1675 if (strncasecmp(pdir->directive, "ThreadsPerChild", 15) == 0) {
1677 break; /* we're in the clear, got ThreadsPerChild first */
1680 /* now to swap the data */
1681 ap_directive_t temp;
1683 temp.directive = pdir->directive;
1684 temp.args = pdir->args;
1685 /* Make sure you don't change 'next', or you may get loops! */
1686 /* XXX: first_child, parent, and data can never be set
1687 * for these directives, right? -aaron */
1688 temp.filename = pdir->filename;
1689 temp.line_num = pdir->line_num;
1691 pdir->directive = max_clients->directive;
1692 pdir->args = max_clients->args;
1693 pdir->filename = max_clients->filename;
1694 pdir->line_num = max_clients->line_num;
1696 max_clients->directive = temp.directive;
1697 max_clients->args = temp.args;
1698 max_clients->filename = temp.filename;
1699 max_clients->line_num = temp.line_num;
1703 else if (!max_clients
1704 && strncasecmp(pdir->directive, "MaxClients", 10) == 0) {
1709 debug = ap_exists_config_define("DEBUG");
1712 no_detach = one_process = 1;
1715 one_process = ap_exists_config_define("ONE_PROCESS");
1716 no_detach = ap_exists_config_define("NO_DETACH");
1719 /* sigh, want this only the second time around */
1720 if (restart_num++ == 1) {
1724 rv = apr_proc_detach(no_detach ? APR_PROC_DETACH_FOREGROUND
1725 : APR_PROC_DETACH_DAEMONIZE);
1726 if (rv != APR_SUCCESS) {
1727 ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
1728 "apr_proc_detach failed");
1729 return HTTP_INTERNAL_SERVER_ERROR;
1732 parent_pid = ap_my_pid = getpid();
1735 unixd_pre_config(ptemp);
1736 ap_listen_pre_config();
1737 ap_daemons_to_start = DEFAULT_START_DAEMON;
1738 min_spare_threads = DEFAULT_MIN_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD;
1739 max_spare_threads = DEFAULT_MAX_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD;
1740 ap_daemons_limit = server_limit;
1741 ap_threads_per_child = DEFAULT_THREADS_PER_CHILD;
1742 ap_pid_fname = DEFAULT_PIDLOG;
1743 ap_lock_fname = DEFAULT_LOCKFILE;
1744 ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
1745 ap_extended_status = 0;
1747 apr_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir));
1752 static void worker_hooks(apr_pool_t *p)
1754 /* The worker open_logs phase must run before the core's, or stderr
1755 * will be redirected to a file, and the messages won't print to the
1758 static const char *const aszSucc[] = {"core.c", NULL};
1761 ap_hook_open_logs(worker_open_logs, NULL, aszSucc, APR_HOOK_MIDDLE);
1762 ap_hook_pre_config(worker_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
1765 static const char *set_daemons_to_start(cmd_parms *cmd, void *dummy,
1768 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1773 ap_daemons_to_start = atoi(arg);
1777 static const char *set_min_spare_threads(cmd_parms *cmd, void *dummy,
1780 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1785 min_spare_threads = atoi(arg);
1786 if (min_spare_threads <= 0) {
1787 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1788 "WARNING: detected MinSpareThreads set to non-positive.");
1789 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1790 "Resetting to 1 to avoid almost certain Apache failure.");
1791 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1792 "Please read the documentation.");
1793 min_spare_threads = 1;
1799 static const char *set_max_spare_threads(cmd_parms *cmd, void *dummy,
1802 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1807 max_spare_threads = atoi(arg);
1811 static const char *set_max_clients (cmd_parms *cmd, void *dummy,
1815 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1820 /* It is ok to use ap_threads_per_child here because we are
1821 * sure that it gets set before MaxClients in the pre_config stage. */
1822 max_clients = atoi(arg);
1823 if (max_clients < ap_threads_per_child) {
1824 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1825 "WARNING: MaxClients (%d) must be at least as large",
1827 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1828 " large as ThreadsPerChild (%d). Automatically",
1829 ap_threads_per_child);
1830 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1831 " increasing MaxClients to %d.",
1832 ap_threads_per_child);
1833 max_clients = ap_threads_per_child;
1835 ap_daemons_limit = max_clients / ap_threads_per_child;
1836 if ((max_clients > 0) && (max_clients % ap_threads_per_child)) {
1837 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1838 "WARNING: MaxClients (%d) is not an integer multiple",
1840 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1841 " of ThreadsPerChild (%d), lowering MaxClients to %d",
1842 ap_threads_per_child,
1843 ap_daemons_limit * ap_threads_per_child);
1844 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1845 " for a maximum of %d child processes,",
1847 max_clients = ap_daemons_limit * ap_threads_per_child;
1849 if (ap_daemons_limit > server_limit) {
1850 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1851 "WARNING: MaxClients of %d would require %d servers,",
1852 max_clients, ap_daemons_limit);
1853 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1854 " and would exceed the ServerLimit value of %d.",
1856 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1857 " Automatically lowering MaxClients to %d. To increase,",
1859 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1860 " please see the ServerLimit directive.");
1861 ap_daemons_limit = server_limit;
1863 else if (ap_daemons_limit < 1) {
1864 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1865 "WARNING: Require MaxClients > 0, setting to 1");
1866 ap_daemons_limit = 1;
1871 static const char *set_threads_per_child (cmd_parms *cmd, void *dummy,
1874 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1879 ap_threads_per_child = atoi(arg);
1880 if (ap_threads_per_child > thread_limit) {
1881 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1882 "WARNING: ThreadsPerChild of %d exceeds ThreadLimit "
1883 "value of %d", ap_threads_per_child,
1885 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1886 "threads, lowering ThreadsPerChild to %d. To increase, please"
1887 " see the", thread_limit);
1888 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1889 " ThreadLimit directive.");
1890 ap_threads_per_child = thread_limit;
1892 else if (ap_threads_per_child < 1) {
1893 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1894 "WARNING: Require ThreadsPerChild > 0, setting to 1");
1895 ap_threads_per_child = 1;
1900 static const char *set_server_limit (cmd_parms *cmd, void *dummy, const char *arg)
1902 int tmp_server_limit;
1904 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1909 tmp_server_limit = atoi(arg);
1910 /* you cannot change ServerLimit across a restart; ignore
1913 if (first_server_limit &&
1914 tmp_server_limit != server_limit) {
1915 /* how do we log a message? the error log is a bit bucket at this
1916 * point; we'll just have to set a flag so that ap_mpm_run()
1917 * logs a warning later
1919 changed_limit_at_restart = 1;
1922 server_limit = tmp_server_limit;
1924 if (server_limit > MAX_SERVER_LIMIT) {
1925 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1926 "WARNING: ServerLimit of %d exceeds compile time limit "
1927 "of %d servers,", server_limit, MAX_SERVER_LIMIT);
1928 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1929 " lowering ServerLimit to %d.", MAX_SERVER_LIMIT);
1930 server_limit = MAX_SERVER_LIMIT;
1932 else if (server_limit < 1) {
1933 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1934 "WARNING: Require ServerLimit > 0, setting to 1");
1940 static const char *set_thread_limit (cmd_parms *cmd, void *dummy, const char *arg)
1942 int tmp_thread_limit;
1944 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1949 tmp_thread_limit = atoi(arg);
1950 /* you cannot change ThreadLimit across a restart; ignore
1953 if (first_thread_limit &&
1954 tmp_thread_limit != thread_limit) {
1955 /* how do we log a message? the error log is a bit bucket at this
1956 * point; we'll just have to set a flag so that ap_mpm_run()
1957 * logs a warning later
1959 changed_limit_at_restart = 1;
1962 thread_limit = tmp_thread_limit;
1964 if (thread_limit > MAX_THREAD_LIMIT) {
1965 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1966 "WARNING: ThreadLimit of %d exceeds compile time limit "
1967 "of %d servers,", thread_limit, MAX_THREAD_LIMIT);
1968 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1969 " lowering ThreadLimit to %d.", MAX_THREAD_LIMIT);
1970 thread_limit = MAX_THREAD_LIMIT;
1972 else if (thread_limit < 1) {
1973 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1974 "WARNING: Require ThreadLimit > 0, setting to 1");
1980 static const command_rec worker_cmds[] = {
1981 UNIX_DAEMON_COMMANDS,
1983 AP_INIT_TAKE1("StartServers", set_daemons_to_start, NULL, RSRC_CONF,
1984 "Number of child processes launched at server startup"),
1985 AP_INIT_TAKE1("MinSpareThreads", set_min_spare_threads, NULL, RSRC_CONF,
1986 "Minimum number of idle children, to handle request spikes"),
1987 AP_INIT_TAKE1("MaxSpareThreads", set_max_spare_threads, NULL, RSRC_CONF,
1988 "Maximum number of idle children"),
1989 AP_INIT_TAKE1("MaxClients", set_max_clients, NULL, RSRC_CONF,
1990 "Maximum number of children alive at the same time"),
1991 AP_INIT_TAKE1("ThreadsPerChild", set_threads_per_child, NULL, RSRC_CONF,
1992 "Number of threads each child creates"),
1993 AP_INIT_TAKE1("ServerLimit", set_server_limit, NULL, RSRC_CONF,
1994 "Maximum value of MaxClients for this run of Apache"),
1995 AP_INIT_TAKE1("ThreadLimit", set_thread_limit, NULL, RSRC_CONF,
1996 "Maximum worker threads in a server for this run of Apache"),
2000 module AP_MODULE_DECLARE_DATA mpm_worker_module = {
2002 NULL, /* hook to run before apache parses args */
2003 NULL, /* create per-directory config structure */
2004 NULL, /* merge per-directory config structures */
2005 NULL, /* create per-server config structure */
2006 NULL, /* merge per-server config structures */
2007 worker_cmds, /* command apr_table_t */
2008 worker_hooks /* register_hooks */