1 /* ====================================================================
2 * The Apache Software License, Version 1.1
4 * Copyright (c) 2000 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.
60 #include "apr_portable.h"
61 #include "apr_strings.h"
62 #include "apr_file_io.h"
63 #include "apr_thread_proc.h"
65 #if APR_HAVE_SYS_SOCKET_H
66 #include <sys/socket.h>
68 #if APR_HAVE_SYS_WAIT_H
74 #include "ap_config.h"
76 #include "http_main.h"
78 #include "http_config.h" /* for read_config */
79 #include "http_core.h" /* for get_remote_host */
80 #include "http_connection.h"
83 #include "mpm_common.h"
84 #include "ap_listen.h"
85 #include "scoreboard.h"
87 #ifdef HAVE_NETINET_TCP_H
88 #include <netinet/tcp.h>
95 * Actual definitions of config globals
98 int ap_threads_per_child=0; /* Worker threads per child */
99 int ap_max_requests_per_child=0;
100 static const char *ap_pid_fname=NULL;
101 static int ap_daemons_to_start=0;
102 static int min_spare_threads=0;
103 static int max_spare_threads=0;
104 static int ap_daemons_limit=0;
105 static int workers_may_exit = 0;
106 static int requests_this_child;
107 static int num_listensocks = 0;
108 static apr_socket_t **listensocks;
110 /* The structure used to pass unique initialization info to each thread */
115 apr_pool_t *tpool; /* "pthread" would be confusing */
119 * The max child slot ever assigned, preserved across restarts. Necessary
120 * to deal with MaxClients changes across SIGWINCH restarts. We use this
121 * value to optimize routines that have to scan the entire scoreboard.
123 int ap_max_daemons_limit = -1;
125 char ap_coredump_dir[MAX_STRING_LEN];
127 static apr_file_t *pipe_of_death_in = NULL;
128 static apr_file_t *pipe_of_death_out = NULL;
129 static pthread_mutex_t pipe_of_death_mutex;
131 /* *Non*-shared http_main globals... */
133 server_rec *ap_server_conf;
135 /* one_process --- debugging mode variable; can be set from the command line
136 * with the -X flag. If set, this gets you the child_main loop running
137 * in the process which originally started up (no detach, no make_child),
138 * which is a pretty nice debugging environment. (You'll get a SIGHUP
139 * early in standalone_main; just continue through. This is the server
140 * trying to kill off any child processes which it might have lying
141 * around --- Apache doesn't keep track of their pids, it just sends
142 * SIGHUP to the process group, ignoring it in the root process.
143 * Continue through and you'll be fine.).
146 static int one_process = 0;
149 int raise_sigstop_flags;
152 static apr_pool_t *pconf; /* Pool for config stuff */
153 static apr_pool_t *pchild; /* Pool for httpd child stuff */
155 unsigned int ap_my_pid; /* Linux getpid() doesn't work except in main
156 thread. Use this instead */
157 /* Keep track of the number of worker threads currently active */
158 static int worker_thread_count;
159 static pthread_mutex_t worker_thread_count_mutex;
161 /* Locks for accept serialization */
162 static apr_lock_t *accept_mutex;
163 static const char *lock_fname;
165 #ifdef NO_SERIALIZED_ACCEPT
166 #define SAFE_ACCEPT(stmt) APR_SUCCESS
168 #define SAFE_ACCEPT(stmt) (stmt)
171 AP_DECLARE(int) ap_get_max_daemons(void)
173 return ap_max_daemons_limit;
176 /* a clean exit from a child with proper cleanup */
177 static void clean_child_exit(int code) __attribute__ ((noreturn));
178 void clean_child_exit(int code)
181 apr_pool_destroy(pchild);
186 /* handle all varieties of core dumping signals */
187 static void sig_coredump(int sig)
189 chdir(ap_coredump_dir);
190 apr_signal(sig, SIG_DFL);
191 kill(ap_my_pid, sig);
192 /* At this point we've got sig blocked, because we're still inside
193 * the signal handler. When we leave the signal handler it will
194 * be unblocked, and we'll take the signal... and coredump or whatever
195 * is appropriate for this particular Unix. In addition the parent
196 * will see the real signal we received -- whereas if we called
197 * abort() here, the parent would only see SIGABRT.
201 static void just_die(int sig)
206 /*****************************************************************
207 * Connection structures and accounting...
210 /* volatile just in case */
211 static int volatile shutdown_pending;
212 static int volatile restart_pending;
213 static int volatile is_graceful;
214 ap_generation_t volatile ap_my_generation;
217 * ap_start_shutdown() and ap_start_restart(), below, are a first stab at
218 * functions to initiate shutdown or restart without relying on signals.
219 * Previously this was initiated in sig_term() and restart() signal handlers,
220 * but we want to be able to start a shutdown/restart from other sources --
221 * e.g. on Win32, from the service manager. Now the service manager can
222 * call ap_start_shutdown() or ap_start_restart() as appropiate. Note that
223 * these functions can also be called by the child processes, since global
224 * variables are no longer used to pass on the required action to the parent.
226 * These should only be called from the parent process itself, since the
227 * parent process will use the shutdown_pending and restart_pending variables
228 * to determine whether to shutdown or restart. The child process should
229 * call signal_parent() directly to tell the parent to die -- this will
230 * cause neither of those variable to be set, which the parent will
231 * assume means something serious is wrong (which it will be, for the
232 * child to force an exit) and so do an exit anyway.
235 static void ap_start_shutdown(void)
237 if (shutdown_pending == 1) {
238 /* Um, is this _probably_ not an error, if the user has
239 * tried to do a shutdown twice quickly, so we won't
240 * worry about reporting it.
244 shutdown_pending = 1;
247 /* do a graceful restart if graceful == 1 */
248 static void ap_start_restart(int graceful)
251 if (restart_pending == 1) {
252 /* Probably not an error - don't bother reporting it */
256 is_graceful = graceful;
258 apr_pool_cleanup_kill(pconf, NULL, ap_cleanup_scoreboard);
262 static void sig_term(int sig)
267 static void restart(int sig)
270 ap_start_restart(sig == SIGWINCH);
276 static void set_signals(void)
278 #ifndef NO_USE_SIGACTION
281 sigemptyset(&sa.sa_mask);
285 sa.sa_handler = sig_coredump;
286 #if defined(SA_ONESHOT)
287 sa.sa_flags = SA_ONESHOT;
288 #elif defined(SA_RESETHAND)
289 sa.sa_flags = SA_RESETHAND;
291 if (sigaction(SIGSEGV, &sa, NULL) < 0)
292 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGSEGV)");
294 if (sigaction(SIGBUS, &sa, NULL) < 0)
295 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGBUS)");
298 if (sigaction(SIGABORT, &sa, NULL) < 0)
299 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGABORT)");
302 if (sigaction(SIGABRT, &sa, NULL) < 0)
303 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGABRT)");
306 if (sigaction(SIGILL, &sa, NULL) < 0)
307 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGILL)");
311 sa.sa_handler = sig_term;
312 if (sigaction(SIGTERM, &sa, NULL) < 0)
313 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGTERM)");
315 if (sigaction(SIGINT, &sa, NULL) < 0)
316 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGINT)");
319 sa.sa_handler = SIG_DFL;
320 if (sigaction(SIGXCPU, &sa, NULL) < 0)
321 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGXCPU)");
324 sa.sa_handler = SIG_DFL;
325 if (sigaction(SIGXFSZ, &sa, NULL) < 0)
326 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGXFSZ)");
329 sa.sa_handler = SIG_IGN;
330 if (sigaction(SIGPIPE, &sa, NULL) < 0)
331 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGPIPE)");
334 /* we want to ignore HUPs and WINCH while we're busy processing one */
335 sigaddset(&sa.sa_mask, SIGHUP);
336 sigaddset(&sa.sa_mask, SIGWINCH);
337 sa.sa_handler = restart;
338 if (sigaction(SIGHUP, &sa, NULL) < 0)
339 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGHUP)");
340 if (sigaction(SIGWINCH, &sa, NULL) < 0)
341 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGWINCH)");
344 apr_signal(SIGSEGV, sig_coredump);
346 apr_signal(SIGBUS, sig_coredump);
349 apr_signal(SIGABORT, sig_coredump);
350 #endif /* SIGABORT */
352 apr_signal(SIGABRT, sig_coredump);
355 apr_signal(SIGILL, sig_coredump);
358 apr_signal(SIGXCPU, SIG_DFL);
361 apr_signal(SIGXFSZ, SIG_DFL);
365 apr_signal(SIGTERM, sig_term);
367 apr_signal(SIGHUP, restart);
370 apr_signal(SIGWINCH, restart);
371 #endif /* SIGWINCH */
373 apr_signal(SIGPIPE, SIG_IGN);
379 /*****************************************************************
380 * Here follows a long bunch of generic server bookkeeping stuff...
383 int ap_graceful_stop_signalled(void)
385 /* XXX - Does this really work? - Manoj */
389 /*****************************************************************
390 * Child process main loop.
393 static void process_socket(apr_pool_t *p, apr_socket_t *sock, int my_child_num, int my_thread_num)
395 conn_rec *current_conn;
396 long conn_id = AP_ID_FROM_CHILD_THREAD(my_child_num, my_thread_num);
399 (void) apr_os_sock_get(&csd, sock);
401 if (csd >= FD_SETSIZE) {
402 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, 0, NULL,
403 "new file descriptor %d is too large; you probably need "
404 "to rebuild Apache with a larger FD_SETSIZE "
407 apr_socket_close(sock);
411 ap_sock_disable_nagle(sock);
413 (void) ap_update_child_status(my_child_num, my_thread_num,
414 SERVER_BUSY_READ, (request_rec *) NULL);
416 current_conn = ap_new_connection(p, ap_server_conf, sock, conn_id);
418 ap_process_connection(current_conn);
419 ap_lingering_close(current_conn);
422 /* Sets workers_may_exit if we received a character on the pipe_of_death */
423 static void check_pipe_of_death(void)
425 pthread_mutex_lock(&pipe_of_death_mutex);
426 if (!workers_may_exit) {
431 ret = apr_recv(listensocks[0], &pipe_read_char, &n);
432 if (APR_STATUS_IS_EAGAIN(ret)) {
433 /* It lost the lottery. It must continue to suffer
434 * through a life of servitude. */
437 /* It won the lottery (or something else is very
438 * wrong). Embrace death with open arms. */
439 workers_may_exit = 1;
442 pthread_mutex_unlock(&pipe_of_death_mutex);
445 static void * worker_thread(void * dummy)
447 proc_info * ti = dummy;
448 int process_slot = ti->pid;
449 int thread_slot = ti->tid;
450 apr_pool_t *tpool = ti->tpool;
451 apr_socket_t *csd = NULL;
452 apr_pool_t *ptrans; /* Pool for per-transaction stuff */
453 apr_socket_t *sd = NULL;
455 int curr_pollfd, last_pollfd = 0;
456 apr_pollfd_t *pollset;
461 apr_pool_create(&ptrans, tpool);
463 pthread_mutex_lock(&worker_thread_count_mutex);
464 worker_thread_count++;
465 pthread_mutex_unlock(&worker_thread_count_mutex);
467 apr_poll_setup(&pollset, num_listensocks+1, tpool);
468 for(n=0 ; n <= num_listensocks ; ++n)
469 apr_poll_socket_add(pollset, listensocks[n], APR_POLLIN);
471 /* TODO: Switch to a system where threads reuse the results from earlier
472 poll calls - manoj */
474 workers_may_exit |= (ap_max_requests_per_child != 0) && (requests_this_child <= 0);
475 if (workers_may_exit) break;
477 (void) ap_update_child_status(process_slot, thread_slot, SERVER_READY,
478 (request_rec *) NULL);
479 if ((rv = SAFE_ACCEPT(apr_lock_aquire(accept_mutex)))
481 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
482 "apr_lock_aquire failed. Attempting to shutdown "
483 "process gracefully.");
484 workers_may_exit = 1;
487 while (!workers_may_exit) {
491 ret = apr_poll(pollset, &n, -1);
492 if (ret != APR_SUCCESS) {
493 if (APR_STATUS_IS_EINTR(ret)) {
497 /* apr_poll() will only return errors in catastrophic
498 * circumstances. Let's try exiting gracefully, for now. */
499 ap_log_error(APLOG_MARK, APLOG_ERR, ret, (const server_rec *)
500 ap_server_conf, "apr_poll: (listen)");
501 workers_may_exit = 1;
504 if (workers_may_exit) break;
506 apr_poll_revents_get(&event, listensocks[0], pollset);
507 if (event & APR_POLLIN) {
508 /* A process got a signal on the shutdown pipe. Check if we're
509 * the lucky process to die. */
510 check_pipe_of_death();
514 if (num_listensocks == 1) {
515 sd = ap_listeners->sd;
519 /* find a listener */
520 curr_pollfd = last_pollfd;
523 if (curr_pollfd > num_listensocks) {
526 /* XXX: Should we check for POLLERR? */
527 apr_poll_revents_get(&event, listensocks[curr_pollfd], pollset);
528 if (event & APR_POLLIN) {
529 last_pollfd = curr_pollfd;
530 sd=listensocks[curr_pollfd];
533 } while (curr_pollfd != last_pollfd);
537 if (!workers_may_exit) {
538 if ((rv = apr_accept(&csd, sd, ptrans)) != APR_SUCCESS) {
540 ap_log_error(APLOG_MARK, APLOG_ERR, rv, ap_server_conf,
543 if ((rv = SAFE_ACCEPT(apr_lock_release(accept_mutex)))
545 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
546 "apr_lock_release failed. Attempting to shutdown "
547 "process gracefully.");
548 workers_may_exit = 1;
551 process_socket(ptrans, csd, process_slot, thread_slot);
552 requests_this_child--;
556 if ((rv = SAFE_ACCEPT(apr_lock_release(accept_mutex)))
558 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
559 "apr_lock_release failed. Attempting to shutdown "
560 "process gracefully.");
561 workers_may_exit = 1;
565 apr_clear_pool(ptrans);
568 apr_pool_destroy(tpool);
569 ap_update_child_status(process_slot, thread_slot, SERVER_DEAD,
570 (request_rec *) NULL);
571 pthread_mutex_lock(&worker_thread_count_mutex);
572 worker_thread_count--;
573 if (worker_thread_count == 0) {
574 /* All the threads have exited, now finish the shutdown process
575 * by signalling the sigwait thread */
576 kill(ap_my_pid, SIGTERM);
578 pthread_mutex_unlock(&worker_thread_count_mutex);
584 static void child_main(int child_num_arg)
589 pthread_attr_t thread_attr;
591 int my_child_num = child_num_arg;
592 proc_info *my_info = NULL;
597 ap_my_pid = getpid();
598 apr_pool_create(&pchild, pconf);
600 /*stuff to do before we switch id's, so we have permissions.*/
601 reopen_scoreboard(pchild);
603 rv = SAFE_ACCEPT(apr_lock_child_init(&accept_mutex, lock_fname,
605 if (rv != APR_SUCCESS) {
606 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
607 "Couldn't initialize cross-process lock in child");
608 clean_child_exit(APEXIT_CHILDFATAL);
611 if (unixd_setup_child()) {
612 clean_child_exit(APEXIT_CHILDFATAL);
615 ap_child_init_hook(pchild, ap_server_conf);
617 /*done with init critical section */
619 /* All threads should mask signals out, accoring to sigwait(2) man page */
620 sigfillset(&sig_mask);
622 #ifdef SIGPROCMASK_SETS_THREAD_MASK
623 if (sigprocmask(SIG_SETMASK, &sig_mask, NULL) != 0) {
624 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf, "sigprocmask");
627 if ((rv = pthread_sigmask(SIG_SETMASK, &sig_mask, NULL)) != 0) {
628 #ifdef PTHREAD_SETS_ERRNO
631 ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf, "pthread_sigmask");
635 requests_this_child = ap_max_requests_per_child;
637 /* Set up the pollfd array */
638 listensocks = apr_pcalloc(pchild,
639 sizeof(*listensocks) * (num_listensocks + 1));
640 #if APR_FILES_AS_SOCKETS
641 apr_socket_from_file(&listensocks[0], pipe_of_death_in);
643 for (lr = ap_listeners, i = 1; i <= num_listensocks; lr = lr->next, ++i)
644 listensocks[i]=lr->sd;
646 /* Setup worker threads */
648 worker_thread_count = 0;
649 pthread_mutex_init(&worker_thread_count_mutex, NULL);
650 pthread_mutex_init(&pipe_of_death_mutex, NULL);
651 pthread_attr_init(&thread_attr);
652 #ifdef PTHREAD_ATTR_SETDETACHSTATE_ARG2_ADDR
656 pthread_attr_setdetachstate(&thread_attr, &on);
659 pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);
661 for (i=0; i < ap_threads_per_child; i++) {
663 my_info = (proc_info *)malloc(sizeof(proc_info));
664 if (my_info == NULL) {
665 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf,
666 "malloc: out of memory");
667 clean_child_exit(APEXIT_CHILDFATAL);
669 my_info->pid = my_child_num;
672 apr_pool_create(&my_info->tpool, pchild);
674 /* We are creating threads right now */
675 (void) ap_update_child_status(my_child_num, i, SERVER_STARTING,
676 (request_rec *) NULL);
678 if ((rv = pthread_create(&thread, &thread_attr, worker_thread, my_info))) {
679 #ifdef PTHREAD_SETS_ERRNO
682 ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
683 "pthread_create: unable to create worker thread");
684 /* In case system resources are maxxed out, we don't want
685 Apache running away with the CPU trying to fork over and
686 over and over again if we exit. */
688 clean_child_exit(APEXIT_CHILDFATAL);
691 worker_thread(my_info);
692 /* The SIGTERM shouldn't let us reach this point, but just in case... */
693 clean_child_exit(APEXIT_OK);
696 /* We let each thread update it's own scoreboard entry. This is done
697 * because it let's us deal with tid better.
701 pthread_attr_destroy(&thread_attr);
703 /* This thread will be the one responsible for handling signals */
704 sigemptyset(&sig_mask);
705 sigaddset(&sig_mask, SIGTERM);
706 sigaddset(&sig_mask, SIGINT);
707 ap_sigwait(&sig_mask, &signal_received);
708 switch (signal_received) {
711 just_die(signal_received);
714 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf,
715 "received impossible signal: %d", signal_received);
720 static int make_child(server_rec *s, int slot)
724 if (slot + 1 > ap_max_daemons_limit) {
725 ap_max_daemons_limit = slot + 1;
730 ap_scoreboard_image->parent[slot].pid = getpid();
734 /* Tag this slot as occupied so that perform_idle_server_maintenance
735 * doesn't try to steal it */
736 (void) ap_update_child_status(slot, 0, SERVER_STARTING, (request_rec *) NULL);
738 if ((pid = fork()) == -1) {
739 ap_log_error(APLOG_MARK, APLOG_ERR, errno, s, "fork: Unable to fork new process");
741 /* fork didn't succeed. Fix the scoreboard or else
742 * it will say SERVER_STARTING forever and ever
744 (void) ap_update_child_status(slot, 0, SERVER_DEAD, (request_rec *) NULL);
746 /* In case system resources are maxxed out, we don't want
747 Apache running away with the CPU trying to fork over and
748 over and over again. */
755 #ifdef AIX_BIND_PROCESSOR
756 /* By default, AIX binds to a single processor. This bit unbinds
757 children which will then bind to another CPU.
759 #include <sys/processor.h>
760 int status = bindprocessor(BINDPROCESS, (int)getpid(),
761 PROCESSOR_CLASS_ANY);
763 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, errno, ap_server_conf,
764 "processor unbind failed %d", status);
767 RAISE_SIGSTOP(MAKE_CHILD);
769 apr_signal(SIGTERM, just_die);
775 ap_scoreboard_image->parent[slot].pid = pid;
779 /* start up a bunch of children */
780 static void startup_children(int number_to_start)
784 for (i = 0; number_to_start && i < ap_daemons_limit; ++i) {
785 if (ap_scoreboard_image->parent[i].pid != 0) {
788 if (make_child(ap_server_conf, i) < 0) {
797 * idle_spawn_rate is the number of children that will be spawned on the
798 * next maintenance cycle if there aren't enough idle servers. It is
799 * doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by
800 * without the need to spawn.
802 static int idle_spawn_rate = 1;
803 #ifndef MAX_SPAWN_RATE
804 #define MAX_SPAWN_RATE (32)
806 static int hold_off_on_exponential_spawning;
808 static void perform_idle_server_maintenance(void)
811 int idle_thread_count;
814 int free_slots[MAX_SPAWN_RATE];
820 /* initialize the free_list */
823 idle_thread_count = 0;
827 ap_sync_scoreboard_image();
828 for (i = 0; i < ap_daemons_limit; ++i) {
829 /* Initialization to satisfy the compiler. It doesn't know
830 * that ap_threads_per_child is always > 0 */
831 int status = SERVER_DEAD;
832 int any_dying_threads = 0;
833 int all_dead_threads = 1;
834 int idle_thread_addition = 0;
836 if (i >= ap_max_daemons_limit && free_length == idle_spawn_rate)
838 for (j = 0; j < ap_threads_per_child; j++) {
839 ss = &ap_scoreboard_image->servers[i][j];
842 any_dying_threads = any_dying_threads || (status == SERVER_DEAD)
843 || (status == SERVER_GRACEFUL);
844 all_dead_threads = all_dead_threads && (status == SERVER_DEAD);
846 /* We consider a starting server as idle because we started it
847 * at least a cycle ago, and if it still hasn't finished starting
848 * then we're just going to swamp things worse by forking more.
849 * So we hopefully won't need to fork more if we count it.
850 * This depends on the ordering of SERVER_READY and SERVER_STARTING.
852 if (status <= SERVER_READY) {
853 ++idle_thread_addition;
856 if (all_dead_threads && free_length < idle_spawn_rate) {
857 free_slots[free_length] = i;
860 if (!all_dead_threads) {
863 if (!any_dying_threads) {
865 idle_thread_count += idle_thread_addition;
868 ap_max_daemons_limit = last_non_dead + 1;
870 if (idle_thread_count > max_spare_threads) {
871 /* Kill off one child */
872 char char_of_death = '!';
873 if ((rv = apr_file_write(pipe_of_death_out, &char_of_death, &one)) != APR_SUCCESS) {
874 ap_log_error(APLOG_MARK, APLOG_WARNING, rv, ap_server_conf, "write pipe_of_death");
878 else if (idle_thread_count < min_spare_threads) {
879 /* terminate the free list */
880 if (free_length == 0) {
881 /* only report this condition once */
882 static int reported = 0;
885 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, 0, ap_server_conf,
886 "server reached MaxClients setting, consider"
887 " raising the MaxClients setting");
894 if (idle_spawn_rate >= 8) {
895 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0, ap_server_conf,
896 "server seems busy, (you may need "
897 "to increase StartServers, ThreadsPerChild "
898 "or Min/MaxSpareThreads), "
899 "spawning %d children, there are around %d idle "
900 "threads, and %d total children", idle_spawn_rate,
901 idle_thread_count, total_non_dead);
903 for (i = 0; i < free_length; ++i) {
904 make_child(ap_server_conf, free_slots[i]);
906 /* the next time around we want to spawn twice as many if this
907 * wasn't good enough, but not if we've just done a graceful
909 if (hold_off_on_exponential_spawning) {
910 --hold_off_on_exponential_spawning;
912 else if (idle_spawn_rate < MAX_SPAWN_RATE) {
913 idle_spawn_rate *= 2;
922 static void server_main_loop(int remaining_children_to_start)
929 while (!restart_pending && !shutdown_pending) {
930 ap_wait_or_timeout(&status, &pid, pconf);
933 ap_process_child_status(&pid, status);
934 /* non-fatal death... note that it's gone in the scoreboard. */
935 child_slot = find_child_by_pid(&pid);
936 if (child_slot >= 0) {
937 for (i = 0; i < ap_threads_per_child; i++)
938 ap_update_child_status(child_slot, i, SERVER_DEAD, (request_rec *) NULL);
940 if (remaining_children_to_start
941 && child_slot < ap_daemons_limit) {
942 /* we're still doing a 1-for-1 replacement of dead
943 * children with new children
945 make_child(ap_server_conf, child_slot);
946 --remaining_children_to_start;
948 #if APR_HAS_OTHER_CHILD
950 else if (apr_proc_other_child_read(&pid, status) == 0) {
954 else if (is_graceful) {
955 /* Great, we've probably just lost a slot in the
956 * scoreboard. Somehow we don't know about this child.
958 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, 0,
960 "long lost child came home! (pid %ld)",
963 /* Don't perform idle maintenance when a child dies,
964 * only do it when there's a timeout. Remember only a
965 * finite number of children can die, and it's pretty
966 * pathological for a lot to die suddenly.
970 else if (remaining_children_to_start) {
971 /* we hit a 1 second timeout in which none of the previous
972 * generation of children needed to be reaped... so assume
973 * they're all done, and pick up the slack if any is left.
975 startup_children(remaining_children_to_start);
976 remaining_children_to_start = 0;
977 /* In any event we really shouldn't do the code below because
978 * few of the servers we just started are in the IDLE state
979 * yet, so we'd mistakenly create an extra server.
984 perform_idle_server_maintenance();
988 int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s)
990 int remaining_children_to_start;
996 rv = apr_file_pipe_create(&pipe_of_death_in, &pipe_of_death_out, pconf);
997 if (rv != APR_SUCCESS) {
998 ap_log_error(APLOG_MARK, APLOG_ERR, rv,
999 (const server_rec*) ap_server_conf,
1000 "apr_file_pipe_create (pipe_of_death)");
1004 if ((rv = apr_file_pipe_timeout_set(pipe_of_death_in, 0)) != APR_SUCCESS) {
1005 ap_log_error(APLOG_MARK, APLOG_ERR, rv,
1006 (const server_rec*) ap_server_conf,
1007 "apr_file_pipe_timeout_set (pipe_of_death)");
1011 if ((num_listensocks = ap_setup_listeners(ap_server_conf)) < 1) {
1012 /* XXX: hey, what's the right way for the mpm to indicate a fatal error? */
1013 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ALERT, 0, s,
1014 "no listening sockets available, shutting down");
1017 ap_log_pid(pconf, ap_pid_fname);
1019 /* Initialize cross-process accept lock */
1020 lock_fname = apr_psprintf(_pconf, "%s.%u",
1021 ap_server_root_relative(_pconf, lock_fname),
1023 rv = apr_lock_create(&accept_mutex, APR_MUTEX, APR_LOCKALL,
1024 lock_fname, _pconf);
1025 if (rv != APR_SUCCESS) {
1026 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s,
1027 "Couldn't create accept lock");
1033 ap_create_scoreboard(pconf, SB_SHARED);
1037 /* Don't thrash... */
1038 if (max_spare_threads < min_spare_threads + ap_threads_per_child)
1039 max_spare_threads = min_spare_threads + ap_threads_per_child;
1041 /* If we're doing a graceful_restart then we're going to see a lot
1042 * of children exiting immediately when we get into the main loop
1043 * below (because we just sent them SIGWINCH). This happens pretty
1044 * rapidly... and for each one that exits we'll start a new one until
1045 * we reach at least daemons_min_free. But we may be permitted to
1046 * start more than that, so we'll just keep track of how many we're
1047 * supposed to start up without the 1 second penalty between each fork.
1049 remaining_children_to_start = ap_daemons_to_start;
1050 if (remaining_children_to_start > ap_daemons_limit) {
1051 remaining_children_to_start = ap_daemons_limit;
1054 startup_children(remaining_children_to_start);
1055 remaining_children_to_start = 0;
1058 /* give the system some time to recover before kicking into
1059 * exponential mode */
1060 hold_off_on_exponential_spawning = 10;
1063 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,
1064 "%s configured -- resuming normal operations",
1065 ap_get_server_version());
1066 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0, ap_server_conf,
1067 "Server built: %s", ap_get_server_built());
1068 restart_pending = shutdown_pending = 0;
1070 server_main_loop(remaining_children_to_start);
1072 if (shutdown_pending) {
1073 /* Time to gracefully shut down:
1074 * Kill child processes, tell them to call child_exit, etc...
1076 if (unixd_killpg(getpgrp(), SIGTERM) < 0) {
1077 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGTERM");
1079 ap_reclaim_child_processes(1); /* Start with SIGTERM */
1081 /* cleanup pid file on normal shutdown */
1083 const char *pidfile = NULL;
1084 pidfile = ap_server_root_relative (pconf, ap_pid_fname);
1085 if ( pidfile != NULL && unlink(pidfile) == 0)
1086 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0,
1088 "removed PID file %s (pid=%ld)",
1089 pidfile, (long)getpid());
1092 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,
1093 "caught SIGTERM, shutting down");
1098 /* we've been told to restart */
1099 apr_signal(SIGHUP, SIG_IGN);
1102 /* not worth thinking about */
1106 /* advance to the next generation */
1107 /* XXX: we really need to make sure this new generation number isn't in
1108 * use by any of the children.
1111 ap_scoreboard_image->global.running_generation = ap_my_generation;
1112 update_scoreboard_global();
1116 char char_of_death = '!';
1118 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,
1119 "SIGWINCH received. Doing graceful restart");
1121 /* give the children the signal to die */
1122 for (i = 0; i < ap_daemons_limit;) {
1123 if ((rv = apr_file_write(pipe_of_death_in, &char_of_death, &one)) != APR_SUCCESS) {
1124 if (APR_STATUS_IS_EINTR(rv)) continue;
1125 ap_log_error(APLOG_MARK, APLOG_WARNING, rv, ap_server_conf, "write pipe_of_death");
1130 /* This is mostly for debugging... so that we know what is still
1131 * gracefully dealing with existing request.
1134 for (i = 0; i < ap_daemons_limit; ++i) {
1135 for (j = 0; j < ap_threads_per_child; j++) {
1136 if (ap_scoreboard_image->servers[i][j].status != SERVER_DEAD) {
1137 ap_scoreboard_image->servers[i][j].status = SERVER_GRACEFUL;
1143 /* Kill 'em all. Since the child acts the same on the parents SIGTERM
1144 * and a SIGHUP, we may as well use the same signal, because some user
1145 * pthreads are stealing signals from us left and right.
1147 if (unixd_killpg(getpgrp(), SIGTERM) < 0) {
1148 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGTERM");
1150 ap_reclaim_child_processes(1); /* Start with SIGTERM */
1151 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,
1152 "SIGHUP received. Attempting to restart");
1157 static void mpmt_pthread_pre_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp)
1159 static int restart_num = 0;
1162 one_process = !!ap_exists_config_define("ONE_PROCESS");
1163 no_detach = !!ap_exists_config_define("NO_DETACH");
1165 /* sigh, want this only the second time around */
1166 if (restart_num++ == 1) {
1169 if (!one_process && !no_detach) {
1172 ap_my_pid = getpid();
1175 unixd_pre_config(ptemp);
1176 ap_listen_pre_config();
1177 ap_daemons_to_start = DEFAULT_START_DAEMON;
1178 min_spare_threads = DEFAULT_MIN_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD;
1179 max_spare_threads = DEFAULT_MAX_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD;
1180 ap_daemons_limit = HARD_SERVER_LIMIT;
1181 ap_threads_per_child = DEFAULT_THREADS_PER_CHILD;
1182 ap_pid_fname = DEFAULT_PIDLOG;
1183 ap_scoreboard_fname = DEFAULT_SCOREBOARD;
1184 lock_fname = DEFAULT_LOCKFILE;
1185 ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
1186 ap_extended_status = 0;
1188 apr_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir));
1191 static void mpmt_pthread_hooks(apr_pool_t *p)
1196 ap_hook_pre_config(mpmt_pthread_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
1200 static const char *set_pidfile(cmd_parms *cmd, void *dummy, const char *arg)
1202 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1207 if (cmd->server->is_virtual) {
1208 return "PidFile directive not allowed in <VirtualHost>";
1214 static const char *set_scoreboard(cmd_parms *cmd, void *dummy,
1217 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1222 ap_scoreboard_fname = arg;
1226 static const char *set_lockfile(cmd_parms *cmd, void *dummy, const char *arg)
1228 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1237 static const char *set_daemons_to_start(cmd_parms *cmd, void *dummy,
1240 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1245 ap_daemons_to_start = atoi(arg);
1249 static const char *set_min_spare_threads(cmd_parms *cmd, void *dummy,
1252 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1257 min_spare_threads = atoi(arg);
1258 if (min_spare_threads <= 0) {
1259 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1260 "WARNING: detected MinSpareThreads set to non-positive.");
1261 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1262 "Resetting to 1 to avoid almost certain Apache failure.");
1263 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1264 "Please read the documentation.");
1265 min_spare_threads = 1;
1271 static const char *set_max_spare_threads(cmd_parms *cmd, void *dummy,
1274 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1279 max_spare_threads = atoi(arg);
1283 static const char *set_server_limit (cmd_parms *cmd, void *dummy,
1286 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1291 ap_daemons_limit = atoi(arg);
1292 if (ap_daemons_limit > HARD_SERVER_LIMIT) {
1293 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1294 "WARNING: MaxClients of %d exceeds compile time limit "
1295 "of %d servers,", ap_daemons_limit, HARD_SERVER_LIMIT);
1296 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1297 " lowering MaxClients to %d. To increase, please "
1298 "see the", HARD_SERVER_LIMIT);
1299 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1300 " HARD_SERVER_LIMIT define in %s.",
1301 AP_MPM_HARD_LIMITS_FILE);
1302 ap_daemons_limit = HARD_SERVER_LIMIT;
1304 else if (ap_daemons_limit < 1) {
1305 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, "WARNING: Require MaxClients > 0, setting to 1");
1306 ap_daemons_limit = 1;
1311 static const char *set_threads_per_child (cmd_parms *cmd, void *dummy,
1314 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1319 ap_threads_per_child = atoi(arg);
1320 if (ap_threads_per_child > HARD_THREAD_LIMIT) {
1321 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1322 "WARNING: ThreadsPerChild of %d exceeds compile time"
1323 "limit of %d threads,", ap_threads_per_child,
1325 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1326 " lowering ThreadsPerChild to %d. To increase, please"
1327 " see the", HARD_THREAD_LIMIT);
1328 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1329 " HARD_THREAD_LIMIT define in %s.",
1330 AP_MPM_HARD_LIMITS_FILE);
1332 else if (ap_threads_per_child < 1) {
1333 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1334 "WARNING: Require ThreadsPerChild > 0, setting to 1");
1335 ap_threads_per_child = 1;
1340 static const char *set_max_requests(cmd_parms *cmd, void *dummy,
1343 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1348 ap_max_requests_per_child = atoi(arg);
1353 static const char *set_coredumpdir (cmd_parms *cmd, void *dummy,
1358 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1363 fname = ap_server_root_relative(cmd->pool, arg);
1364 if ((apr_stat(&finfo, fname, APR_FINFO_TYPE, cmd->pool) != APR_SUCCESS)
1365 || (finfo.filetype != APR_DIR)) {
1366 return apr_pstrcat(cmd->pool, "CoreDumpDirectory ", fname,
1367 " does not exist or is not a directory", NULL);
1369 apr_cpystrn(ap_coredump_dir, fname, sizeof(ap_coredump_dir));
1373 static const command_rec mpmt_pthread_cmds[] = {
1374 UNIX_DAEMON_COMMANDS
1376 AP_INIT_TAKE1("PidFile", set_pidfile, NULL, RSRC_CONF,
1377 "A file for logging the server process ID"),
1378 AP_INIT_TAKE1("ScoreBoardFile", set_scoreboard, NULL, RSRC_CONF,
1379 "A file for Apache to maintain runtime process management information"),
1380 AP_INIT_TAKE1("LockFile", set_lockfile, NULL, RSRC_CONF,
1381 "The lockfile used when Apache needs to lock the accept() call"),
1382 AP_INIT_TAKE1("StartServers", set_daemons_to_start, NULL, RSRC_CONF,
1383 "Number of child processes launched at server startup"),
1384 AP_INIT_TAKE1("MinSpareThreads", set_min_spare_threads, NULL, RSRC_CONF,
1385 "Minimum number of idle children, to handle request spikes"),
1386 AP_INIT_TAKE1("MaxSpareThreads", set_max_spare_threads, NULL, RSRC_CONF,
1387 "Maximum number of idle children"),
1388 AP_INIT_TAKE1("MaxClients", set_server_limit, NULL, RSRC_CONF,
1389 "Maximum number of children alive at the same time"),
1390 AP_INIT_TAKE1("ThreadsPerChild", set_threads_per_child, NULL, RSRC_CONF,
1391 "Number of threads each child creates"),
1392 AP_INIT_TAKE1("MaxRequestsPerChild", set_max_requests, NULL, RSRC_CONF,
1393 "Maximum number of requests a particular child serves before dying."),
1394 AP_INIT_TAKE1("CoreDumpDirectory", set_coredumpdir, NULL, RSRC_CONF,
1395 "The location of the directory Apache changes to before dumping core"),
1399 module AP_MODULE_DECLARE_DATA mpm_mpmt_pthread_module = {
1401 NULL, /* hook to run before apache parses args */
1402 NULL, /* create per-directory config structure */
1403 NULL, /* merge per-directory config structures */
1404 NULL, /* create per-server config structure */
1405 NULL, /* merge per-server config structures */
1406 mpmt_pthread_cmds, /* command apr_table_t */
1407 mpmt_pthread_hooks /* register_hooks */