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.
61 #include "apr_portable.h"
62 #include "apr_strings.h"
63 #include "apr_file_io.h"
64 #include "apr_thread_proc.h"
65 #include "ap_config.h"
67 #include "http_main.h"
69 #include "http_config.h" /* for read_config */
70 #include "http_core.h" /* for get_remote_host */
71 #include "http_connection.h"
74 #include "mpm_common.h"
75 #include "ap_listen.h"
76 #include "scoreboard.h"
78 #ifdef HAVE_NETINET_TCP_H
79 #include <netinet/tcp.h>
81 #ifdef HAVE_SYS_SOCKET_H
82 #include <sys/socket.h>
84 #ifdef HAVE_SYS_WAIT_H
91 * Actual definitions of config globals
94 int ap_threads_per_child=0; /* Worker threads per child */
95 int ap_max_requests_per_child=0;
96 static const char *ap_pid_fname=NULL;
97 AP_DECLARE_DATA const char *ap_scoreboard_fname=NULL;
98 static int ap_daemons_to_start=0;
99 static int min_spare_threads=0;
100 static int max_spare_threads=0;
101 static int ap_daemons_limit=0;
102 static time_t ap_restart_time=0;
103 AP_DECLARE_DATA int ap_extended_status = 0;
104 static int workers_may_exit = 0;
105 static int requests_this_child;
106 static int num_listensocks = 0;
107 static apr_socket_t **listensocks;
109 /* The structure used to pass unique initialization info to each thread */
114 apr_pool_t *tpool; /* "pthread" would be confusing */
118 * The max child slot ever assigned, preserved across restarts. Necessary
119 * to deal with MaxClients changes across SIGWINCH restarts. We use this
120 * value to optimize routines that have to scan the entire scoreboard.
122 int ap_max_daemons_limit = -1;
124 char ap_coredump_dir[MAX_STRING_LEN];
126 static apr_file_t *pipe_of_death_in = NULL;
127 static apr_file_t *pipe_of_death_out = NULL;
128 static pthread_mutex_t pipe_of_death_mutex;
130 /* *Non*-shared http_main globals... */
132 server_rec *ap_server_conf;
134 /* one_process --- debugging mode variable; can be set from the command line
135 * with the -X flag. If set, this gets you the child_main loop running
136 * in the process which originally started up (no detach, no make_child),
137 * which is a pretty nice debugging environment. (You'll get a SIGHUP
138 * early in standalone_main; just continue through. This is the server
139 * trying to kill off any child processes which it might have lying
140 * around --- Apache doesn't keep track of their pids, it just sends
141 * SIGHUP to the process group, ignoring it in the root process.
142 * Continue through and you'll be fine.).
145 static int one_process = 0;
148 int raise_sigstop_flags;
151 static apr_pool_t *pconf; /* Pool for config stuff */
152 static apr_pool_t *pchild; /* Pool for httpd child stuff */
154 unsigned int ap_my_pid; /* Linux getpid() doesn't work except in main
155 thread. Use this instead */
156 /* Keep track of the number of worker threads currently active */
157 static int worker_thread_count;
158 static pthread_mutex_t worker_thread_count_mutex;
160 /* Locks for accept serialization */
161 static apr_lock_t *accept_mutex;
162 static const char *lock_fname;
164 #ifdef NO_SERIALIZED_ACCEPT
165 #define SAFE_ACCEPT(stmt) APR_SUCCESS
167 #define SAFE_ACCEPT(stmt) (stmt)
170 AP_DECLARE(int) ap_get_max_daemons(void)
172 return ap_max_daemons_limit;
175 /* a clean exit from a child with proper cleanup */
176 static void clean_child_exit(int code) __attribute__ ((noreturn));
177 void clean_child_exit(int code)
180 apr_destroy_pool(pchild);
185 /* handle all varieties of core dumping signals */
186 static void sig_coredump(int sig)
188 chdir(ap_coredump_dir);
189 apr_signal(sig, SIG_DFL);
190 kill(ap_my_pid, sig);
191 /* At this point we've got sig blocked, because we're still inside
192 * the signal handler. When we leave the signal handler it will
193 * be unblocked, and we'll take the signal... and coredump or whatever
194 * is appropriate for this particular Unix. In addition the parent
195 * will see the real signal we received -- whereas if we called
196 * abort() here, the parent would only see SIGABRT.
200 static void just_die(int sig)
205 /*****************************************************************
206 * Connection structures and accounting...
209 /* volatile just in case */
210 static int volatile shutdown_pending;
211 static int volatile restart_pending;
212 static int volatile is_graceful;
213 ap_generation_t volatile ap_my_generation;
216 * ap_start_shutdown() and ap_start_restart(), below, are a first stab at
217 * functions to initiate shutdown or restart without relying on signals.
218 * Previously this was initiated in sig_term() and restart() signal handlers,
219 * but we want to be able to start a shutdown/restart from other sources --
220 * e.g. on Win32, from the service manager. Now the service manager can
221 * call ap_start_shutdown() or ap_start_restart() as appropiate. Note that
222 * these functions can also be called by the child processes, since global
223 * variables are no longer used to pass on the required action to the parent.
225 * These should only be called from the parent process itself, since the
226 * parent process will use the shutdown_pending and restart_pending variables
227 * to determine whether to shutdown or restart. The child process should
228 * call signal_parent() directly to tell the parent to die -- this will
229 * cause neither of those variable to be set, which the parent will
230 * assume means something serious is wrong (which it will be, for the
231 * child to force an exit) and so do an exit anyway.
234 static void ap_start_shutdown(void)
236 if (shutdown_pending == 1) {
237 /* Um, is this _probably_ not an error, if the user has
238 * tried to do a shutdown twice quickly, so we won't
239 * worry about reporting it.
243 shutdown_pending = 1;
246 /* do a graceful restart if graceful == 1 */
247 static void ap_start_restart(int graceful)
250 if (restart_pending == 1) {
251 /* Probably not an error - don't bother reporting it */
255 is_graceful = graceful;
257 apr_kill_cleanup(pconf, NULL, ap_cleanup_shared_mem);
261 static void sig_term(int sig)
266 static void restart(int sig)
269 ap_start_restart(sig == SIGWINCH);
275 static void set_signals(void)
277 #ifndef NO_USE_SIGACTION
280 sigemptyset(&sa.sa_mask);
284 sa.sa_handler = sig_coredump;
285 #if defined(SA_ONESHOT)
286 sa.sa_flags = SA_ONESHOT;
287 #elif defined(SA_RESETHAND)
288 sa.sa_flags = SA_RESETHAND;
290 if (sigaction(SIGSEGV, &sa, NULL) < 0)
291 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGSEGV)");
293 if (sigaction(SIGBUS, &sa, NULL) < 0)
294 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGBUS)");
297 if (sigaction(SIGABORT, &sa, NULL) < 0)
298 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGABORT)");
301 if (sigaction(SIGABRT, &sa, NULL) < 0)
302 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGABRT)");
305 if (sigaction(SIGILL, &sa, NULL) < 0)
306 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGILL)");
310 sa.sa_handler = sig_term;
311 if (sigaction(SIGTERM, &sa, NULL) < 0)
312 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGTERM)");
314 if (sigaction(SIGINT, &sa, NULL) < 0)
315 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGINT)");
318 sa.sa_handler = SIG_DFL;
319 if (sigaction(SIGXCPU, &sa, NULL) < 0)
320 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGXCPU)");
323 sa.sa_handler = SIG_DFL;
324 if (sigaction(SIGXFSZ, &sa, NULL) < 0)
325 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGXFSZ)");
328 sa.sa_handler = SIG_IGN;
329 if (sigaction(SIGPIPE, &sa, NULL) < 0)
330 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGPIPE)");
333 /* we want to ignore HUPs and WINCH while we're busy processing one */
334 sigaddset(&sa.sa_mask, SIGHUP);
335 sigaddset(&sa.sa_mask, SIGWINCH);
336 sa.sa_handler = restart;
337 if (sigaction(SIGHUP, &sa, NULL) < 0)
338 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGHUP)");
339 if (sigaction(SIGWINCH, &sa, NULL) < 0)
340 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGWINCH)");
343 apr_signal(SIGSEGV, sig_coredump);
345 apr_signal(SIGBUS, sig_coredump);
348 apr_signal(SIGABORT, sig_coredump);
349 #endif /* SIGABORT */
351 apr_signal(SIGABRT, sig_coredump);
354 apr_signal(SIGILL, sig_coredump);
357 apr_signal(SIGXCPU, SIG_DFL);
360 apr_signal(SIGXFSZ, SIG_DFL);
364 apr_signal(SIGTERM, sig_term);
366 apr_signal(SIGHUP, restart);
369 apr_signal(SIGWINCH, restart);
370 #endif /* SIGWINCH */
372 apr_signal(SIGPIPE, SIG_IGN);
378 /*****************************************************************
379 * Here follows a long bunch of generic server bookkeeping stuff...
382 int ap_graceful_stop_signalled(void)
384 /* XXX - Does this really work? - Manoj */
388 /*****************************************************************
389 * Child process main loop.
392 static void process_socket(apr_pool_t *p, apr_socket_t *sock, int my_child_num, int my_thread_num)
394 conn_rec *current_conn;
395 long conn_id = my_child_num * HARD_THREAD_LIMIT + my_thread_num;
398 (void) apr_get_os_sock(&csd, sock);
400 if (csd >= FD_SETSIZE) {
401 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, 0, NULL,
402 "new file descriptor %d is too large; you probably need "
403 "to rebuild Apache with a larger FD_SETSIZE "
406 apr_close_socket(sock);
410 ap_sock_disable_nagle(sock);
412 (void) ap_update_child_status(my_child_num, my_thread_num,
413 SERVER_BUSY_READ, (request_rec *) NULL);
415 current_conn = ap_new_connection(p, ap_server_conf, sock, conn_id);
417 ap_process_connection(current_conn);
418 ap_lingering_close(current_conn);
420 /* Sets workers_may_exit if we received a character on the pipe_of_death */
421 static void check_pipe_of_death(void)
423 pthread_mutex_lock(&pipe_of_death_mutex);
424 if (!workers_may_exit) {
429 ret = apr_recv(listensocks[0], &pipe_read_char, &n);
430 if (APR_STATUS_IS_EAGAIN(ret)) {
431 /* It lost the lottery. It must continue to suffer
432 * through a life of servitude. */
435 /* It won the lottery (or something else is very
436 * wrong). Embrace death with open arms. */
437 workers_may_exit = 1;
440 pthread_mutex_unlock(&pipe_of_death_mutex);
443 static void * worker_thread(void * dummy)
445 proc_info * ti = dummy;
446 int process_slot = ti->pid;
447 int thread_slot = ti->tid;
448 apr_pool_t *tpool = ti->tpool;
449 apr_socket_t *csd = NULL;
450 apr_pool_t *ptrans; /* Pool for per-transaction stuff */
451 apr_socket_t *sd = NULL;
453 int curr_pollfd, last_pollfd = 0;
454 apr_pollfd_t *pollset;
459 apr_create_pool(&ptrans, tpool);
461 pthread_mutex_lock(&worker_thread_count_mutex);
462 worker_thread_count++;
463 pthread_mutex_unlock(&worker_thread_count_mutex);
465 apr_setup_poll(&pollset, num_listensocks+1, tpool);
466 for(n=0 ; n <= num_listensocks ; ++n)
467 apr_add_poll_socket(pollset, listensocks[n], APR_POLLIN);
469 /* TODO: Switch to a system where threads reuse the results from earlier
470 poll calls - manoj */
472 workers_may_exit |= (ap_max_requests_per_child != 0) && (requests_this_child <= 0);
473 if (workers_may_exit) break;
475 (void) ap_update_child_status(process_slot, thread_slot, SERVER_READY,
476 (request_rec *) NULL);
477 if ((rv = SAFE_ACCEPT(apr_lock(accept_mutex)))
479 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
480 "apr_lock failed. Attempting to shutdown "
481 "process gracefully.");
482 workers_may_exit = 1;
485 while (!workers_may_exit) {
489 ret = apr_poll(pollset, &n, -1);
490 if (ret != APR_SUCCESS) {
491 if (APR_STATUS_IS_EINTR(ret)) {
495 /* apr_poll() will only return errors in catastrophic
496 * circumstances. Let's try exiting gracefully, for now. */
497 ap_log_error(APLOG_MARK, APLOG_ERR, ret, (const server_rec *)
498 ap_server_conf, "apr_poll: (listen)");
499 workers_may_exit = 1;
502 if (workers_may_exit) break;
504 apr_get_revents(&event, listensocks[0], pollset);
505 if (event & APR_POLLIN) {
506 /* A process got a signal on the shutdown pipe. Check if we're
507 * the lucky process to die. */
508 check_pipe_of_death();
512 if (num_listensocks == 1) {
513 sd = ap_listeners->sd;
517 /* find a listener */
518 curr_pollfd = last_pollfd;
521 if (curr_pollfd > num_listensocks) {
524 /* XXX: Should we check for POLLERR? */
525 apr_get_revents(&event, listensocks[curr_pollfd], pollset);
526 if (event & APR_POLLIN) {
527 last_pollfd = curr_pollfd;
528 sd=listensocks[curr_pollfd];
531 } while (curr_pollfd != last_pollfd);
535 if (!workers_may_exit) {
536 if ((rv = apr_accept(&csd, sd, ptrans)) != APR_SUCCESS) {
538 ap_log_error(APLOG_MARK, APLOG_ERR, rv, ap_server_conf,
541 if ((rv = SAFE_ACCEPT(apr_unlock(accept_mutex)))
543 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
544 "apr_unlock failed. Attempting to shutdown "
545 "process gracefully.");
546 workers_may_exit = 1;
549 process_socket(ptrans, csd, process_slot, thread_slot);
550 requests_this_child--;
554 if ((rv = SAFE_ACCEPT(apr_unlock(accept_mutex)))
556 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
557 "apr_unlock failed. Attempting to shutdown "
558 "process gracefully.");
559 workers_may_exit = 1;
563 apr_clear_pool(ptrans);
566 apr_destroy_pool(tpool);
567 ap_update_child_status(process_slot, thread_slot, SERVER_DEAD,
568 (request_rec *) NULL);
569 pthread_mutex_lock(&worker_thread_count_mutex);
570 worker_thread_count--;
571 if (worker_thread_count == 0) {
572 /* All the threads have exited, now finish the shutdown process
573 * by signalling the sigwait thread */
574 kill(ap_my_pid, SIGTERM);
576 pthread_mutex_unlock(&worker_thread_count_mutex);
582 static void child_main(int child_num_arg)
587 pthread_attr_t thread_attr;
589 int my_child_num = child_num_arg;
590 proc_info *my_info = NULL;
595 ap_my_pid = getpid();
596 apr_create_pool(&pchild, pconf);
598 /*stuff to do before we switch id's, so we have permissions.*/
599 reopen_scoreboard(pchild);
601 rv = SAFE_ACCEPT(apr_child_init_lock(&accept_mutex, lock_fname,
603 if (rv != APR_SUCCESS) {
604 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
605 "Couldn't initialize cross-process lock in child");
606 clean_child_exit(APEXIT_CHILDFATAL);
609 if (unixd_setup_child()) {
610 clean_child_exit(APEXIT_CHILDFATAL);
613 ap_child_init_hook(pchild, ap_server_conf);
615 /*done with init critical section */
617 /* All threads should mask signals out, accoring to sigwait(2) man page */
618 sigfillset(&sig_mask);
620 #ifdef SIGPROCMASK_SETS_THREAD_MASK
621 if (sigprocmask(SIG_SETMASK, &sig_mask, NULL) != 0) {
622 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf, "sigprocmask");
625 if ((rv = pthread_sigmask(SIG_SETMASK, &sig_mask, NULL)) != 0) {
626 #ifdef PTHREAD_SETS_ERRNO
629 ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf, "pthread_sigmask");
633 requests_this_child = ap_max_requests_per_child;
635 /* Set up the pollfd array */
636 listensocks = apr_pcalloc(pchild,
637 sizeof(*listensocks) * (num_listensocks + 1));
638 #if APR_FILES_AS_SOCKETS
639 apr_socket_from_file(&listensocks[0], pipe_of_death_in);
641 for (lr = ap_listeners, i = 1; i <= num_listensocks; lr = lr->next, ++i)
642 listensocks[i]=lr->sd;
644 /* Setup worker threads */
646 worker_thread_count = 0;
647 pthread_mutex_init(&worker_thread_count_mutex, NULL);
648 pthread_mutex_init(&pipe_of_death_mutex, NULL);
649 pthread_attr_init(&thread_attr);
650 #ifdef PTHREAD_ATTR_SETDETACHSTATE_ARG2_ADDR
654 pthread_attr_setdetachstate(&thread_attr, &on);
657 pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);
659 for (i=0; i < ap_threads_per_child; i++) {
661 my_info = (proc_info *)malloc(sizeof(proc_info));
662 if (my_info == NULL) {
663 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf,
664 "malloc: out of memory");
665 clean_child_exit(APEXIT_CHILDFATAL);
667 my_info->pid = my_child_num;
670 apr_create_pool(&my_info->tpool, pchild);
672 /* We are creating threads right now */
673 (void) ap_update_child_status(my_child_num, i, SERVER_STARTING,
674 (request_rec *) NULL);
676 if ((rv = pthread_create(&thread, &thread_attr, worker_thread, my_info))) {
677 #ifdef PTHREAD_SETS_ERRNO
680 ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
681 "pthread_create: unable to create worker thread");
682 /* In case system resources are maxxed out, we don't want
683 Apache running away with the CPU trying to fork over and
684 over and over again if we exit. */
686 clean_child_exit(APEXIT_CHILDFATAL);
689 worker_thread(my_info);
690 /* The SIGTERM shouldn't let us reach this point, but just in case... */
691 clean_child_exit(APEXIT_OK);
694 /* We let each thread update it's own scoreboard entry. This is done
695 * because it let's us deal with tid better.
699 pthread_attr_destroy(&thread_attr);
701 /* This thread will be the one responsible for handling signals */
702 sigemptyset(&sig_mask);
703 sigaddset(&sig_mask, SIGTERM);
704 sigaddset(&sig_mask, SIGINT);
705 ap_sigwait(&sig_mask, &signal_received);
706 switch (signal_received) {
709 just_die(signal_received);
712 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf,
713 "received impossible signal: %d", signal_received);
718 static int make_child(server_rec *s, int slot, time_t now)
722 if (slot + 1 > ap_max_daemons_limit) {
723 ap_max_daemons_limit = slot + 1;
728 ap_scoreboard_image->parent[slot].pid = getpid();
732 /* Tag this slot as occupied so that perform_idle_server_maintenance
733 * doesn't try to steal it */
734 (void) ap_update_child_status(slot, 0, SERVER_STARTING, (request_rec *) NULL);
736 if ((pid = fork()) == -1) {
737 ap_log_error(APLOG_MARK, APLOG_ERR, errno, s, "fork: Unable to fork new process");
739 /* fork didn't succeed. Fix the scoreboard or else
740 * it will say SERVER_STARTING forever and ever
742 (void) ap_update_child_status(slot, 0, SERVER_DEAD, (request_rec *) NULL);
744 /* In case system resources are maxxed out, we don't want
745 Apache running away with the CPU trying to fork over and
746 over and over again. */
753 #ifdef AIX_BIND_PROCESSOR
754 /* By default, AIX binds to a single processor. This bit unbinds
755 children which will then bind to another CPU.
757 #include <sys/processor.h>
758 int status = bindprocessor(BINDPROCESS, (int)getpid(),
759 PROCESSOR_CLASS_ANY);
761 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, errno, ap_server_conf,
762 "processor unbind failed %d", status);
765 RAISE_SIGSTOP(MAKE_CHILD);
767 apr_signal(SIGTERM, just_die);
773 ap_scoreboard_image->parent[slot].pid = pid;
777 /* start up a bunch of children */
778 static void startup_children(int number_to_start)
782 for (i = 0; number_to_start && i < ap_daemons_limit; ++i) {
783 if (ap_scoreboard_image->parent[i].pid != 0) {
786 if (make_child(ap_server_conf, i, 0) < 0) {
795 * idle_spawn_rate is the number of children that will be spawned on the
796 * next maintenance cycle if there aren't enough idle servers. It is
797 * doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by
798 * without the need to spawn.
800 static int idle_spawn_rate = 1;
801 #ifndef MAX_SPAWN_RATE
802 #define MAX_SPAWN_RATE (32)
804 static int hold_off_on_exponential_spawning;
806 static void perform_idle_server_maintenance(void)
809 int idle_thread_count;
813 int free_slots[MAX_SPAWN_RATE];
819 /* initialize the free_list */
822 idle_thread_count = 0;
826 ap_sync_scoreboard_image();
827 for (i = 0; i < ap_daemons_limit; ++i) {
828 /* Initialization to satisfy the compiler. It doesn't know
829 * that ap_threads_per_child is always > 0 */
830 int status = SERVER_DEAD;
831 int any_dying_threads = 0;
832 int all_dead_threads = 1;
833 int idle_thread_addition = 0;
835 if (i >= ap_max_daemons_limit && free_length == idle_spawn_rate)
837 for (j = 0; j < ap_threads_per_child; j++) {
838 ss = &ap_scoreboard_image->servers[i][j];
841 any_dying_threads = any_dying_threads || (status == SERVER_DEAD)
842 || (status == SERVER_GRACEFUL);
843 all_dead_threads = all_dead_threads && (status == SERVER_DEAD);
845 /* We consider a starting server as idle because we started it
846 * at least a cycle ago, and if it still hasn't finished starting
847 * then we're just going to swamp things worse by forking more.
848 * So we hopefully won't need to fork more if we count it.
849 * This depends on the ordering of SERVER_READY and SERVER_STARTING.
851 if (status <= SERVER_READY) {
852 ++idle_thread_addition;
855 if (all_dead_threads && free_length < idle_spawn_rate) {
856 free_slots[free_length] = i;
859 if (!all_dead_threads) {
862 if (!any_dying_threads) {
864 idle_thread_count += idle_thread_addition;
867 ap_max_daemons_limit = last_non_dead + 1;
869 if (idle_thread_count > max_spare_threads) {
870 /* Kill off one child */
871 char char_of_death = '!';
872 if ((rv = apr_write(pipe_of_death_out, &char_of_death, &one)) != APR_SUCCESS) {
873 ap_log_error(APLOG_MARK, APLOG_WARNING, rv, ap_server_conf, "write pipe_of_death");
877 else if (idle_thread_count < min_spare_threads) {
878 /* terminate the free list */
879 if (free_length == 0) {
880 /* only report this condition once */
881 static int reported = 0;
884 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, 0, ap_server_conf,
885 "server reached MaxClients setting, consider"
886 " raising the MaxClients setting");
893 if (idle_spawn_rate >= 8) {
894 ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0, ap_server_conf,
895 "server seems busy, (you may need "
896 "to increase StartServers, ThreadsPerChild "
897 "or Min/MaxSpareThreads), "
898 "spawning %d children, there are around %d idle "
899 "threads, and %d total children", idle_spawn_rate,
900 idle_thread_count, total_non_dead);
902 for (i = 0; i < free_length; ++i) {
903 make_child(ap_server_conf, free_slots[i], now);
905 /* the next time around we want to spawn twice as many if this
906 * wasn't good enough, but not if we've just done a graceful
908 if (hold_off_on_exponential_spawning) {
909 --hold_off_on_exponential_spawning;
911 else if (idle_spawn_rate < MAX_SPAWN_RATE) {
912 idle_spawn_rate *= 2;
921 static void server_main_loop(int remaining_children_to_start)
928 while (!restart_pending && !shutdown_pending) {
929 ap_wait_or_timeout(&status, &pid, pconf);
932 ap_process_child_status(&pid, status);
933 /* non-fatal death... note that it's gone in the scoreboard. */
934 child_slot = find_child_by_pid(&pid);
935 if (child_slot >= 0) {
936 ap_mpmt_pthread_force_reset_connection_status(child_slot);
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, time(NULL));
946 --remaining_children_to_start;
948 #if APR_HAS_OTHER_CHILD
950 else if (apr_reap_other_child(&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_create_pipe(&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_create_pipe (pipe_of_death)");
1004 if ((rv = apr_set_pipe_timeout(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_set_pipe_timeout (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_create_lock(&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 reinit_scoreboard(pconf);
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_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");
1155 ap_restart_time = time(NULL);
1160 static void mpmt_pthread_pre_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp)
1162 static int restart_num = 0;
1165 one_process = !!getenv("ONE_PROCESS");
1166 no_detach = !!getenv("NO_DETACH");
1168 /* sigh, want this only the second time around */
1169 if (restart_num++ == 1) {
1172 if (!one_process && !no_detach) {
1175 ap_my_pid = getpid();
1178 unixd_pre_config(ptemp);
1179 ap_listen_pre_config();
1180 ap_daemons_to_start = DEFAULT_START_DAEMON;
1181 min_spare_threads = DEFAULT_MIN_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD;
1182 max_spare_threads = DEFAULT_MAX_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD;
1183 ap_daemons_limit = HARD_SERVER_LIMIT;
1184 ap_threads_per_child = DEFAULT_THREADS_PER_CHILD;
1185 ap_pid_fname = DEFAULT_PIDLOG;
1186 ap_scoreboard_fname = DEFAULT_SCOREBOARD;
1187 lock_fname = DEFAULT_LOCKFILE;
1188 ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
1189 ap_extended_status = 0;
1191 apr_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir));
1194 static void mpmt_pthread_hooks(void)
1199 ap_hook_pre_config(mpmt_pthread_pre_config, NULL, NULL, AP_HOOK_MIDDLE);
1203 static const char *set_pidfile(cmd_parms *cmd, void *dummy, const char *arg)
1205 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1210 if (cmd->server->is_virtual) {
1211 return "PidFile directive not allowed in <VirtualHost>";
1217 static const char *set_scoreboard(cmd_parms *cmd, void *dummy,
1220 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1225 ap_scoreboard_fname = arg;
1229 static const char *set_lockfile(cmd_parms *cmd, void *dummy, const char *arg)
1231 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1240 static const char *set_daemons_to_start(cmd_parms *cmd, void *dummy,
1243 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1248 ap_daemons_to_start = atoi(arg);
1252 static const char *set_min_spare_threads(cmd_parms *cmd, void *dummy,
1255 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1260 min_spare_threads = atoi(arg);
1261 if (min_spare_threads <= 0) {
1262 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1263 "WARNING: detected MinSpareThreads set to non-positive.");
1264 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1265 "Resetting to 1 to avoid almost certain Apache failure.");
1266 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1267 "Please read the documentation.");
1268 min_spare_threads = 1;
1274 static const char *set_max_spare_threads(cmd_parms *cmd, void *dummy,
1277 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1282 max_spare_threads = atoi(arg);
1286 static const char *set_server_limit (cmd_parms *cmd, void *dummy,
1289 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1294 ap_daemons_limit = atoi(arg);
1295 if (ap_daemons_limit > HARD_SERVER_LIMIT) {
1296 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1297 "WARNING: MaxClients of %d exceeds compile time limit "
1298 "of %d servers,", ap_daemons_limit, HARD_SERVER_LIMIT);
1299 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1300 " lowering MaxClients to %d. To increase, please "
1301 "see the", HARD_SERVER_LIMIT);
1302 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1303 " HARD_SERVER_LIMIT define in %s.",
1304 AP_MPM_HARD_LIMITS_FILE);
1305 ap_daemons_limit = HARD_SERVER_LIMIT;
1307 else if (ap_daemons_limit < 1) {
1308 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, "WARNING: Require MaxClients > 0, setting to 1");
1309 ap_daemons_limit = 1;
1314 static const char *set_threads_per_child (cmd_parms *cmd, void *dummy,
1317 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1322 ap_threads_per_child = atoi(arg);
1323 if (ap_threads_per_child > HARD_THREAD_LIMIT) {
1324 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1325 "WARNING: ThreadsPerChild of %d exceeds compile time"
1326 "limit of %d threads,", ap_threads_per_child,
1328 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1329 " lowering ThreadsPerChild to %d. To increase, please"
1330 " see the", HARD_THREAD_LIMIT);
1331 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1332 " HARD_THREAD_LIMIT define in %s.",
1333 AP_MPM_HARD_LIMITS_FILE);
1335 else if (ap_threads_per_child < 1) {
1336 ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
1337 "WARNING: Require ThreadsPerChild > 0, setting to 1");
1338 ap_threads_per_child = 1;
1343 static const char *set_max_requests(cmd_parms *cmd, void *dummy,
1346 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1351 ap_max_requests_per_child = atoi(arg);
1356 static const char *set_coredumpdir (cmd_parms *cmd, void *dummy,
1361 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
1366 fname = ap_server_root_relative(cmd->pool, arg);
1367 if ((apr_stat(&finfo, fname, cmd->pool) != APR_SUCCESS) ||
1368 (finfo.filetype != APR_DIR)) {
1369 return apr_pstrcat(cmd->pool, "CoreDumpDirectory ", fname,
1370 " does not exist or is not a directory", NULL);
1372 apr_cpystrn(ap_coredump_dir, fname, sizeof(ap_coredump_dir));
1376 static const command_rec mpmt_pthread_cmds[] = {
1377 UNIX_DAEMON_COMMANDS
1379 AP_INIT_TAKE1("PidFile", set_pidfile, NULL, RSRC_CONF,
1380 "A file for logging the server process ID"),
1381 AP_INIT_TAKE1("ScoreBoardFile", set_scoreboard, NULL, RSRC_CONF,
1382 "A file for Apache to maintain runtime process management information"),
1383 AP_INIT_TAKE1("LockFile", set_lockfile, NULL, RSRC_CONF,
1384 "The lockfile used when Apache needs to lock the accept() call"),
1385 AP_INIT_TAKE1("StartServers", set_daemons_to_start, NULL, RSRC_CONF,
1386 "Number of child processes launched at server startup"),
1387 AP_INIT_TAKE1("MinSpareThreads", set_min_spare_threads, NULL, RSRC_CONF,
1388 "Minimum number of idle children, to handle request spikes"),
1389 AP_INIT_TAKE1("MaxSpareThreads", set_max_spare_threads, NULL, RSRC_CONF,
1390 "Maximum number of idle children"),
1391 AP_INIT_TAKE1("MaxClients", set_server_limit, NULL, RSRC_CONF,
1392 "Maximum number of children alive at the same time"),
1393 AP_INIT_TAKE1("ThreadsPerChild", set_threads_per_child, NULL, RSRC_CONF,
1394 "Number of threads each child creates"),
1395 AP_INIT_TAKE1("MaxRequestsPerChild", set_max_requests, NULL, RSRC_CONF,
1396 "Maximum number of requests a particular child serves before dying."),
1397 AP_INIT_TAKE1("CoreDumpDirectory", set_coredumpdir, NULL, RSRC_CONF,
1398 "The location of the directory Apache changes to before dumping core"),
1402 module AP_MODULE_DECLARE_DATA mpm_mpmt_pthread_module = {
1404 NULL, /* hook to run before apache parses args */
1405 NULL, /* create per-directory config structure */
1406 NULL, /* merge per-directory config structures */
1407 NULL, /* create per-server config structure */
1408 NULL, /* merge per-server config structures */
1409 mpmt_pthread_cmds, /* command apr_table_t */
1410 mpmt_pthread_hooks /* register_hooks */