/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License.
*/
/* Limit on the total --- clients will be locked out if more servers than * this are needed. It is intended solely to keep the server from crashing * when things get out of hand. * * We keep a hard maximum number of servers, for two reasons --- first off, * in case something goes seriously wrong, we want to stop the fork bomb * short of actually crashing the machine we're running on by filling some * kernel table. Secondly, it keeps the size of the scoreboard file small * enough that we can read the whole thing without worrying too much about * the overhead.
*/ #ifndef DEFAULT_SERVER_LIMIT #define DEFAULT_SERVER_LIMIT 256 #endif
/* Admin can't tune ServerLimit beyond MAX_SERVER_LIMIT. We want * some sort of compile-time limit to help catch typos.
*/ #ifndef MAX_SERVER_LIMIT #define MAX_SERVER_LIMIT 200000 #endif
/* data retained by prefork across load/unload of the module * allocated on first call to pre-config hook; located on * subsequent calls to pre-config hook
*/ typedefstruct prefork_retained_data {
ap_unixd_mpm_retained_data *mpm;
int first_server_limit; int maxclients_reported; /* * The max child slot ever assigned, preserved across restarts. Necessary * to deal with MaxRequestWorkers changes across AP_SIG_GRACEFUL restarts. We * use this value to optimize routines that have to scan the entire scoreboard.
*/ int max_daemons_limit; /* * idle_spawn_rate is the number of children that will be spawned on the * next maintenance cycle if there aren't enough idle servers. It is * doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by * without the need to spawn.
*/ int idle_spawn_rate; #ifndef MAX_SPAWN_RATE #define MAX_SPAWN_RATE (32) #endif int hold_off_on_exponential_spawning;
} prefork_retained_data; static prefork_retained_data *retained;
/* one_process --- debugging mode variable; can be set from the command line * with the -X flag. If set, this gets you the child_main loop running * in the process which originally started up (no detach, no make_child), * which is a pretty nice debugging environment. (You'll get a SIGHUP * early in standalone_main; just continue through. This is the server * trying to kill off any child processes which it might have lying * around --- Apache doesn't keep track of their pids, it just sends * SIGHUP to the process group, ignoring it in the root process. * Continue through and you'll be fine.).
*/
staticint one_process = 0;
static apr_pool_t *pconf; /* Pool for config stuff */ static apr_pool_t *pchild; /* Pool for httpd child stuff */
static pid_t ap_my_pid; /* it seems silly to call getpid all the time */ static pid_t parent_pid; staticint my_child_num;
if (retained->mpm->my_generation !=
ap_scoreboard_image->global->running_generation) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, ap_server_conf, APLOGNO(00145) "%s", msg); /* don't exit here... we have a connection to * process, after which point we'll see that the * generation changed and we'll exit cleanly
*/
} else {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(00146) "%s", msg); exit(APEXIT_CHILDFATAL);
}
} return APR_SUCCESS;
}
/* On some architectures it's safe to do unserialized accept()s in the single * Listen case. But it's never safe to do it in the case where there's * multiple Listen statements. Define SINGLE_LISTEN_UNSERIALIZED_ACCEPT * when it's safe in the single Listen case.
*/ #ifdef SINGLE_LISTEN_UNSERIALIZED_ACCEPT #define SAFE_ACCEPT(stmt) (ap_listeners->next ? (stmt) : APR_SUCCESS) #else #define SAFE_ACCEPT(stmt) (stmt) #endif
staticint prefork_query(int query_code, int *result, apr_status_t *rv)
{
*rv = APR_SUCCESS; switch(query_code){ case AP_MPMQ_MAX_DAEMON_USED:
*result = ap_daemons_limit; break; case AP_MPMQ_IS_THREADED:
*result = AP_MPMQ_NOT_SUPPORTED; break; case AP_MPMQ_IS_FORKED:
*result = AP_MPMQ_DYNAMIC; break; case AP_MPMQ_HARD_LIMIT_DAEMONS:
*result = server_limit; break; case AP_MPMQ_HARD_LIMIT_THREADS:
*result = HARD_THREAD_LIMIT; break; case AP_MPMQ_MAX_THREADS:
*result = 1; break; case AP_MPMQ_MIN_SPARE_DAEMONS:
*result = ap_daemons_min_free; break; case AP_MPMQ_MIN_SPARE_THREADS:
*result = 0; break; case AP_MPMQ_MAX_SPARE_DAEMONS:
*result = ap_daemons_max_free; break; case AP_MPMQ_MAX_SPARE_THREADS:
*result = 0; break; case AP_MPMQ_MAX_REQUESTS_DAEMON:
*result = ap_max_requests_per_child; break; case AP_MPMQ_MAX_DAEMONS:
*result = ap_daemons_limit; break; case AP_MPMQ_MPM_STATE:
*result = retained->mpm->mpm_state; break; case AP_MPMQ_GENERATION:
*result = retained->mpm->my_generation; break; default:
*rv = APR_ENOTIMPL; break;
} return OK;
}
/* For a graceful stop, we want the child to exit when done */
die_now = 1;
}
/***************************************************************** * Child process main loop. * The following vars are static to avoid getting clobbered by longjmp(); * they are really private to child_main.
*/
/* Get a sub context for global allocations in this child, so that * we can have cleanups occur when the child exits.
*/
apr_allocator_create(&allocator);
apr_allocator_max_free_set(allocator, ap_max_mem_free);
apr_pool_create_ex(&pchild, pconf, NULL, allocator);
apr_allocator_owner_set(allocator, pchild);
apr_pool_tag(pchild, "pchild");
/* close unused listeners and pods */ for (i = 0; i < retained->mpm->num_buckets; i++) { if (i != child_bucket) {
ap_close_listeners_ex(all_buckets[i].listeners);
ap_mpm_pod_close(all_buckets[i].pod);
}
}
/* needs to be done before we switch UIDs so we have permissions */
ap_reopen_scoreboard(pchild, NULL, 0);
status = SAFE_ACCEPT(apr_proc_mutex_child_init(&my_bucket->mutex,
apr_proc_mutex_lockfile(my_bucket->mutex),
pchild)); if (status != APR_SUCCESS) {
lockfile = apr_proc_mutex_lockfile(my_bucket->mutex);
ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf, APLOGNO(00155) "Couldn't initialize cross-process lock in child " "(%s) (%s)",
lockfile ? lockfile : "none",
apr_proc_mutex_name(my_bucket->mutex));
clean_child_exit(APEXIT_CHILDFATAL);
}
if (ap_run_drop_privileges(pchild, ap_server_conf)) {
clean_child_exit(APEXIT_CHILDFATAL);
}
#if APR_HAS_THREADS /* Save the signal mask and block all the signals from being received by * threads potentially created in child_init() hooks (e.g. mod_watchdog).
*/
child_sigmask(NULL, &sig_mask);
{
apr_status_t rv;
rv = apr_setup_signal_thread(); if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(10271) "Couldn't initialize signal thread");
clean_child_exit(APEXIT_CHILDFATAL);
}
} #endif/* APR_HAS_THREADS */
ap_run_child_init(pchild, ap_server_conf);
#if APR_HAS_THREADS /* Restore the original signal mask for this main thread, the only one * that should possibly get interrupted by signals.
*/
child_sigmask(&sig_mask, NULL); #endif
/* Set up the pollfd array */
status = apr_pollset_create(&pollset, num_listensocks, pchild,
APR_POLLSET_NOCOPY); if (status != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf, APLOGNO(00156) "Couldn't create pollset in child; check system or user limits");
clean_child_exit(APEXIT_CHILDSICK); /* assume temporary resource issue */
}
for (lr = my_bucket->listeners, i = num_listensocks; i--; lr = lr->next) {
apr_pollfd_t *pfd = apr_pcalloc(pchild, sizeof *pfd);
status = apr_pollset_add(pollset, pfd); if (status != APR_SUCCESS) { /* If the child processed a SIGWINCH before setting up the * pollset, this error path is expected and harmless, * since the listener fd was already closed; so don't
* pollute the logs in that case. */ if (!die_now) {
ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf, APLOGNO(00157) "Couldn't add listener to pollset; check system or user limits");
clean_child_exit(APEXIT_CHILDSICK);
}
clean_child_exit(0);
}
lr->accept_func = ap_unixd_accept;
}
retained->mpm->mpm_state = AP_MPMQ_RUNNING;
bucket_alloc = apr_bucket_alloc_create(pchild);
/* die_now is set when AP_SIG_GRACEFUL is received in the child; * {shutdown,restart}_pending are set when a signal is received while * running in single process mode.
*/ while (!die_now
&& !retained->mpm->shutdown_pending
&& !retained->mpm->restart_pending) {
conn_rec *current_conn; void *csd;
/* * (Re)initialize this child to a pre-connection state.
*/
/* * Wait for an acceptable connection to arrive.
*/
/* Lock around "accept", if necessary */
SAFE_ACCEPT(accept_mutex_on());
if (num_listensocks == 1) { /* There is only one listener record, so refer to that one. */
lr = my_bucket->listeners;
} else { /* multiple listening sockets - need to poll */ for (;;) {
apr_int32_t numdesc; const apr_pollfd_t *pdesc;
/* check for termination first so we don't sleep for a while in * poll if already signalled
*/ if (die_now /* in graceful stop/restart */
|| retained->mpm->shutdown_pending
|| retained->mpm->restart_pending) {
SAFE_ACCEPT(accept_mutex_off());
clean_child_exit(0);
}
/* timeout == 10 seconds to avoid a hang at graceful restart/stop * caused by the closing of sockets by the signal handler
*/
status = apr_pollset_poll(pollset, apr_time_from_sec(10),
&numdesc, &pdesc); if (status != APR_SUCCESS) { if (APR_STATUS_IS_TIMEUP(status) ||
APR_STATUS_IS_EINTR(status)) { continue;
} /* Single Unix documents select as returning errnos * EBADF, EINTR, and EINVAL... and in none of those * cases does it make sense to continue. In fact * on Linux 2.0.x we seem to end up with EFAULT * occasionally, and we'd loop forever due to it.
*/
ap_log_error(APLOG_MARK, APLOG_ERR, status,
ap_server_conf, APLOGNO(00158) "apr_pollset_poll: (listen)");
SAFE_ACCEPT(accept_mutex_off());
clean_child_exit(APEXIT_CHILDSICK);
}
/* We can always use pdesc[0], but sockets at position N * could end up completely starved of attention in a very * busy server. Therefore, we round-robin across the * returned set of descriptors. While it is possible that * the returned set of descriptors might flip around and * continue to starve some sockets, we happen to know the * internal pollset implementation retains ordering * stability of the sockets. Thus, the round-robin should * ensure that a socket will eventually be serviced.
*/ if (last_poll_idx >= numdesc)
last_poll_idx = 0;
/* Grab a listener record from the client_data of the poll * descriptor, and advance our saved index to round-robin * the next fetch. * * ### hmm... this descriptor might have POLLERR rather * ### than POLLIN
*/
lr = pdesc[last_poll_idx++].client_data; goto got_fd;
}
}
got_fd: /* if we accept() something we don't want to die, so we have to * defer the exit
*/
status = lr->accept_func(&csd, lr, ptrans);
SAFE_ACCEPT(accept_mutex_off()); /* unlock after "accept" */
/* Check the pod and the generation number after processing a * connection so that we'll go away if a graceful restart occurred * while we were processing the connection or we are the lucky * idle server process that gets to die.
*/ if (ap_mpm_pod_check(my_bucket->pod) == APR_SUCCESS) { /* selected as idle? */
die_now = 1;
} elseif (retained->mpm->my_generation !=
ap_scoreboard_image->global->running_generation) { /* restart? */ /* yeah, this could be non-graceful restart, in which case the * parent will kill us soon enough, but why bother checking?
*/
die_now = 1;
}
}
apr_pool_clear(ptrans); /* kludge to avoid crash in APR reslist cleanup code */
clean_child_exit(0);
}
staticint make_child(server_rec *s, int slot)
{ int bucket = slot % retained->mpm->num_buckets; int pid;
#ifdef _OSD_POSIX /* BS2000 requires a "special" version of fork() before a setuid() call */ if ((pid = os_fork(ap_unixd_config.user_name)) == -1) { #else if ((pid = fork()) == -1) { #endif
ap_log_error(APLOG_MARK, APLOG_ERR, errno, s, APLOGNO(00159) "fork: Unable to fork new process");
/* fork didn't succeed. Fix the scoreboard or else * it will say SERVER_STARTING forever and ever
*/
(void) ap_update_child_status_from_indexes(slot, 0, SERVER_DEAD,
(request_rec *) NULL);
/* In case system resources are maxxed out, we don't want * Apache running away with the CPU trying to fork over and * over and over again.
*/
sleep(10);
return -1;
}
if (!pid) { #if AP_HAS_THREAD_LOCAL
ap_thread_current_after_fork(); #endif
my_bucket = &all_buckets[bucket];
#ifdef HAVE_BINDPROCESSOR /* by default AIX binds to a single processor * this bit unbinds children which will then bind to another cpu
*/ int status = bindprocessor(BINDPROCESS, (int)getpid(),
PROCESSOR_CLASS_ANY); if (status != OK) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, errno,
ap_server_conf, APLOGNO(00160) "processor unbind failed");
} #endif
RAISE_SIGSTOP(MAKE_CHILD);
AP_MONCONTROL(1); /* Disable the parent's signal handlers and set up proper handling in * the child.
*/
apr_signal(SIGHUP, just_die);
apr_signal(SIGTERM, just_die); /* Ignore SIGINT in child. This fixes race-conditions in signals * handling when httpd is running on foreground and user hits ctrl+c. * In this case, SIGINT is sent to all children followed by SIGTERM * from the main process, which interrupts the SIGINT handler and * leads to inconsistency.
*/
apr_signal(SIGINT, SIG_IGN); /* The child process just closes listeners on AP_SIG_GRACEFUL. * The pod is used for signalling the graceful restart.
*/
apr_signal(AP_SIG_GRACEFUL, stop_listening);
child_main(slot, bucket);
}
prefork_note_child_started(slot, pid);
return 0;
}
/* start up a bunch of children */ staticvoid startup_children(int number_to_start)
{ int i;
for (i = 0; number_to_start && i < ap_daemons_limit; ++i) { if (ap_scoreboard_image->servers[i][0].status != SERVER_DEAD) { continue;
} if (make_child(ap_server_conf, i) < 0) { break;
}
--number_to_start;
}
}
staticvoid perform_idle_server_maintenance(apr_pool_t *p)
{ int i; int idle_count;
worker_score *ws; int free_length; int free_slots[MAX_SPAWN_RATE]; int last_non_dead; int total_non_dead;
for (i = 0; i < ap_daemons_limit; ++i) { int status;
if (i >= retained->max_daemons_limit && free_length == retained->idle_spawn_rate) break;
ws = &ap_scoreboard_image->servers[i][0];
status = ws->status; if (status == SERVER_DEAD) { /* try to keep children numbers as low as possible */ if (free_length < retained->idle_spawn_rate) {
free_slots[free_length] = i;
++free_length;
}
} else { /* We consider a starting server as idle because we started it * at least a cycle ago, and if it still hasn't finished starting * then we're just going to swamp things worse by forking more. * So we hopefully won't need to fork more if we count it. * This depends on the ordering of SERVER_READY and SERVER_STARTING.
*/ if (status <= SERVER_READY) {
++ idle_count;
}
++total_non_dead;
last_non_dead = i;
}
}
retained->max_daemons_limit = last_non_dead + 1; if (idle_count > ap_daemons_max_free) { staticint bucket_kill_child_record = -1; /* kill off one child... we use the pod because that'll cause it to * shut down gracefully, in case it happened to pick up a request * while we were counting
*/
bucket_kill_child_record = (bucket_kill_child_record + 1) % retained->mpm->num_buckets;
ap_mpm_pod_signal(all_buckets[bucket_kill_child_record].pod);
retained->idle_spawn_rate = 1;
} elseif (idle_count < ap_daemons_min_free) { /* terminate the free list */ if (free_length == 0) { /* only report this condition once */ if (!retained->maxclients_reported) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, APLOGNO(00161) "server reached MaxRequestWorkers setting, consider" " raising the MaxRequestWorkers setting");
retained->maxclients_reported = 1;
}
retained->idle_spawn_rate = 1;
} else { if (retained->idle_spawn_rate >= 8) {
ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf, APLOGNO(00162) "server seems busy, (you may need " "to increase StartServers, or Min/MaxSpareServers), " "spawning %d children, there are %d idle, and " "%d total children", retained->idle_spawn_rate,
idle_count, total_non_dead);
} for (i = 0; i < free_length; ++i) {
make_child(ap_server_conf, free_slots[i]);
} /* the next time around we want to spawn twice as many if this * wasn't good enough, but not if we've just done a graceful
*/ if (retained->hold_off_on_exponential_spawning) {
--retained->hold_off_on_exponential_spawning;
} elseif (retained->idle_spawn_rate < MAX_SPAWN_RATE) {
retained->idle_spawn_rate *= 2;
}
}
} else {
retained->idle_spawn_rate = 1;
}
}
staticint prefork_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s)
{ int index; int remaining_children_to_start; int i;
ap_log_pid(pconf, ap_pid_fname);
if (!retained->mpm->was_graceful) { if (ap_run_pre_mpm(s->process->pool, SB_SHARED) != OK) {
retained->mpm->mpm_state = AP_MPMQ_STOPPING; return !OK;
} /* fix the generation number in the global score; we just got a new, * cleared scoreboard
*/
ap_scoreboard_image->global->running_generation = retained->mpm->my_generation;
}
/* Don't thrash since num_buckets depends on the * system and the number of online CPU cores...
*/ if (ap_daemons_limit < retained->mpm->num_buckets)
ap_daemons_limit = retained->mpm->num_buckets; if (ap_daemons_to_start < retained->mpm->num_buckets)
ap_daemons_to_start = retained->mpm->num_buckets; if (ap_daemons_min_free < retained->mpm->num_buckets)
ap_daemons_min_free = retained->mpm->num_buckets; if (ap_daemons_max_free < ap_daemons_min_free + retained->mpm->num_buckets)
ap_daemons_max_free = ap_daemons_min_free + retained->mpm->num_buckets;
/* If we're doing a graceful_restart then we're going to see a lot * of children exiting immediately when we get into the main loop * below (because we just sent them AP_SIG_GRACEFUL). This happens pretty * rapidly... and for each one that exits we'll start a new one until * we reach at least daemons_min_free. But we may be permitted to * start more than that, so we'll just keep track of how many we're * supposed to start up without the 1 second penalty between each fork.
*/
remaining_children_to_start = ap_daemons_to_start; if (remaining_children_to_start > ap_daemons_limit) {
remaining_children_to_start = ap_daemons_limit;
} if (!retained->mpm->was_graceful) {
startup_children(remaining_children_to_start);
remaining_children_to_start = 0;
} else { /* give the system some time to recover before kicking into * exponential mode
*/
retained->hold_off_on_exponential_spawning = 10;
}
while (!retained->mpm->restart_pending && !retained->mpm->shutdown_pending) { int child_slot;
apr_exit_why_e exitwhy; int status, processed_status; /* this is a memory leak, but I'll fix it later. */
apr_proc_t pid;
/* XXX: if it takes longer than 1 second for all our children * to start up and get into IDLE state then we may spawn an * extra child
*/ if (pid.pid != -1) {
processed_status = ap_process_child_status(&pid, exitwhy, status);
child_slot = ap_find_child_by_pid(&pid); if (processed_status == APEXIT_CHILDFATAL) { /* fix race condition found in PR 39311 * A child created at the same time as a graceful happens * can find the lock missing and create a fatal error. * It is not fatal for the last generation to be in this state.
*/ if (child_slot < 0
|| ap_get_scoreboard_process(child_slot)->generation
== retained->mpm->my_generation) {
retained->mpm->mpm_state = AP_MPMQ_STOPPING; return !OK;
} else {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ap_server_conf, APLOGNO(00166) "Ignoring fatal error in child of previous " "generation (pid %ld).",
(long)pid.pid);
}
}
/* non-fatal death... note that it's gone in the scoreboard. */ if (child_slot >= 0) {
(void) ap_update_child_status_from_indexes(child_slot, 0, SERVER_DEAD,
(request_rec *) NULL);
prefork_note_child_killed(child_slot, 0, 0); if (processed_status == APEXIT_CHILDSICK) { /* child detected a resource shortage (E[NM]FILE, ENOBUFS, etc) * cut the fork rate to the minimum
*/
retained->idle_spawn_rate = 1;
} elseif (remaining_children_to_start
&& child_slot < ap_daemons_limit) { /* we're still doing a 1-for-1 replacement of dead * children with new children
*/
make_child(ap_server_conf, child_slot);
--remaining_children_to_start;
} #if APR_HAS_OTHER_CHILD
} elseif (apr_proc_other_child_alert(&pid, APR_OC_REASON_DEATH, status) == APR_SUCCESS) { /* handled */ #endif
} elseif (retained->mpm->was_graceful) { /* Great, we've probably just lost a slot in the * scoreboard. Somehow we don't know about this * child.
*/
ap_log_error(APLOG_MARK, APLOG_WARNING,
0, ap_server_conf, APLOGNO(00167) "long lost child came home! (pid %ld)", (long)pid.pid);
} /* Don't perform idle maintenance when a child dies, * only do it when there's a timeout. Remember only a * finite number of children can die, and it's pretty * pathological for a lot to die suddenly.
*/ continue;
} elseif (remaining_children_to_start) { /* we hit a 1 second timeout in which none of the previous * generation of children needed to be reaped... so assume * they're all done, and pick up the slack if any is left.
*/
startup_children(remaining_children_to_start);
remaining_children_to_start = 0; /* In any event we really shouldn't do the code below because * few of the servers we just started are in the IDLE state * yet, so we'd mistakenly create an extra server.
*/ continue;
}
perform_idle_server_maintenance(pconf);
}
retained->mpm->mpm_state = AP_MPMQ_STOPPING;
if (retained->mpm->shutdown_pending && retained->mpm->is_ungraceful) { /* Time to shut down: * Kill child processes, tell them to call child_exit, etc...
*/ if (ap_unixd_killpg(getpgrp(), SIGTERM) < 0) {
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00168) "killpg SIGTERM");
}
ap_reclaim_child_processes(1, /* Start with SIGTERM */
prefork_note_child_killed);
/* cleanup pid file on normal shutdown */
ap_remove_pid(pconf, ap_pid_fname);
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00169) "caught SIGTERM, shutting down");
return DONE;
}
if (retained->mpm->shutdown_pending) { /* Time to perform a graceful shut down: * Reap the inactive children, and ask the active ones * to close their listeners, then wait until they are * all done to exit.
*/ int active_children;
apr_time_t cutoff = 0;
/* Stop listening */
ap_close_listeners();
/* kill off the idle ones */ for (i = 0; i < retained->mpm->num_buckets; i++) {
ap_mpm_pod_killpg(all_buckets[i].pod, retained->max_daemons_limit);
}
/* Send SIGUSR1 to the active children */
active_children = 0; for (index = 0; index < ap_daemons_limit; ++index) { if (ap_scoreboard_image->servers[index][0].status != SERVER_DEAD) { /* Ask each child to close its listeners. */
ap_mpm_safe_kill(MPM_CHILD_PID(index), AP_SIG_GRACEFUL);
active_children++;
}
}
/* Allow each child which actually finished to exit */
ap_relieve_child_processes(prefork_note_child_killed);
if (ap_graceful_shutdown_timeout) {
cutoff = apr_time_now() +
apr_time_from_sec(ap_graceful_shutdown_timeout);
}
/* Don't really exit until each child has finished */
retained->mpm->shutdown_pending = 0; do { /* Pause for a second */
sleep(1);
/* Relieve any children which have now exited */
ap_relieve_child_processes(prefork_note_child_killed);
active_children = 0; for (index = 0; index < ap_daemons_limit; ++index) { if (ap_mpm_safe_kill(MPM_CHILD_PID(index), 0) == APR_SUCCESS) {
active_children = 1; /* Having just one child is enough to stay around */ break;
}
}
} while (!retained->mpm->shutdown_pending && active_children &&
(!ap_graceful_shutdown_timeout || apr_time_now() < cutoff));
/* We might be here because we received SIGTERM, either * way, try and make sure that all of our processes are * really dead.
*/
ap_unixd_killpg(getpgrp(), SIGTERM);
return DONE;
}
/* we've been told to restart */ if (one_process) { /* not worth thinking about */ return DONE;
}
/* advance to the next generation */ /* XXX: we really need to make sure this new generation number isn't in * use by any of the children.
*/
++retained->mpm->my_generation;
ap_scoreboard_image->global->running_generation = retained->mpm->my_generation;
/* kill off the idle ones */ for (i = 0; i < retained->mpm->num_buckets; i++) {
ap_mpm_pod_killpg(all_buckets[i].pod, retained->max_daemons_limit);
}
/* This is mostly for debugging... so that we know what is still * gracefully dealing with existing request. This will break * in a very nasty way if we ever have the scoreboard totally * file-based (no shared memory)
*/ for (index = 0; index < ap_daemons_limit; ++index) { if (ap_scoreboard_image->servers[index][0].status != SERVER_DEAD) {
ap_scoreboard_image->servers[index][0].status = SERVER_GRACEFUL; /* Ask each child to close its listeners. * * NOTE: we use the scoreboard, because if we send SIGUSR1 * to every process in the group, this may include CGI's, * piped loggers, etc. They almost certainly won't handle * it gracefully.
*/
ap_mpm_safe_kill(ap_scoreboard_image->parent[index].pid, AP_SIG_GRACEFUL);
}
}
} else { /* Kill 'em off */ if (ap_unixd_killpg(getpgrp(), SIGHUP) < 0) {
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00172) "killpg SIGHUP");
}
ap_reclaim_child_processes(0, /* Not when just starting up */
prefork_note_child_killed);
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00173) "SIGHUP received. Attempting to restart");
}
return OK;
}
/* This really should be a post_config hook, but the error log is already * redirected by that point, so we need to do this in the open_logs phase.
*/ staticint prefork_open_logs(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s)
{ int startup = 0; int level_flags = 0;
ap_listen_rec **listen_buckets;
apr_status_t rv; char id[16]; int i;
pconf = p;
/* the reverse of pre_config, we want this only the first time around */ if (retained->mpm->module_loads == 1) {
startup = 1;
level_flags |= APLOG_STARTUP;
}
/* sigh, want this only the second time around */ if (retained->mpm->module_loads == 2) { if (!one_process && !foreground) { /* before we detach, setup crash handlers to log to errorlog */
ap_fatal_signal_setup(ap_server_conf, p /* == pconf */);
rv = apr_proc_detach(no_detach ? APR_PROC_DETACH_FOREGROUND
: APR_PROC_DETACH_DAEMONIZE); if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL, APLOGNO(00174) "apr_proc_detach failed"); return HTTP_INTERNAL_SERVER_ERROR;
}
}
}
/* the reverse of pre_config, we want this only the first time around */ if (retained->mpm->module_loads == 1) {
startup = 1;
}
if (server_limit > MAX_SERVER_LIMIT) { if (startup) {
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00175) "WARNING: ServerLimit of %d exceeds compile-time " "limit of %d servers, decreasing to %d.",
server_limit, MAX_SERVER_LIMIT, MAX_SERVER_LIMIT);
} else {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00176) "ServerLimit of %d exceeds compile-time limit " "of %d, decreasing to match",
server_limit, MAX_SERVER_LIMIT);
}
server_limit = MAX_SERVER_LIMIT;
} elseif (server_limit < 1) { if (startup) {
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00177) "WARNING: ServerLimit of %d not allowed, " "increasing to 1.", server_limit);
} else {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00178) "ServerLimit of %d not allowed, increasing to 1",
server_limit);
}
server_limit = 1;
}
/* you cannot change ServerLimit across a restart; ignore * any such attempts
*/ if (!retained->first_server_limit) {
retained->first_server_limit = server_limit;
} elseif (server_limit != retained->first_server_limit) { /* don't need a startup console version here */
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00179) "changing ServerLimit to %d from original value of %d " "not allowed during restart",
server_limit, retained->first_server_limit);
server_limit = retained->first_server_limit;
}
if (ap_daemons_limit > server_limit) { if (startup) {
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00180) "WARNING: MaxRequestWorkers of %d exceeds ServerLimit " "value of %d servers, decreasing MaxRequestWorkers to %d. " "To increase, please see the ServerLimit directive.",
ap_daemons_limit, server_limit, server_limit);
} else {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00181) "MaxRequestWorkers of %d exceeds ServerLimit value " "of %d, decreasing to match",
ap_daemons_limit, server_limit);
}
ap_daemons_limit = server_limit;
} elseif (ap_daemons_limit < 1) { if (startup) {
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00182) "WARNING: MaxRequestWorkers of %d not allowed, " "increasing to 1.", ap_daemons_limit);
} else {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00183) "MaxRequestWorkers of %d not allowed, increasing to 1",
ap_daemons_limit);
}
ap_daemons_limit = 1;
}
/* ap_daemons_to_start > ap_daemons_limit checked in prefork_run() */ if (ap_daemons_to_start < 1) { if (startup) {
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00184) "WARNING: StartServers of %d not allowed, " "increasing to 1.", ap_daemons_to_start);
} else {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00185) "StartServers of %d not allowed, increasing to 1",
ap_daemons_to_start);
}
ap_daemons_to_start = 1;
}
if (ap_daemons_min_free < 1) { if (startup) {
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00186) "WARNING: MinSpareServers of %d not allowed, " "increasing to 1 to avoid almost certain server failure. " "Please read the documentation.", ap_daemons_min_free);
} else {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00187) "MinSpareServers of %d not allowed, increasing to 1",
ap_daemons_min_free);
}
ap_daemons_min_free = 1;
}
/* ap_daemons_max_free < ap_daemons_min_free + 1 checked in prefork_run() */
return OK;
}
staticvoid prefork_hooks(apr_pool_t *p)
{ /* Our open_logs hook function must run before the core's, or stderr * will be redirected to a file, and the messages won't print to the * console.
*/ staticconstchar *const aszSucc[] = {"core.c", NULL};
ap_hook_open_logs(prefork_open_logs, NULL, aszSucc, APR_HOOK_REALLY_FIRST); /* we need to set the MPM state before other pre-config hooks use MPM query * to retrieve it, so register as REALLY_FIRST
*/
ap_hook_pre_config(prefork_pre_config, NULL, NULL, APR_HOOK_REALLY_FIRST);
ap_hook_check_config(prefork_check_config, NULL, NULL, APR_HOOK_MIDDLE);
ap_hook_mpm(prefork_run, NULL, NULL, APR_HOOK_MIDDLE);
ap_hook_mpm_query(prefork_query, NULL, NULL, APR_HOOK_MIDDLE);
ap_hook_mpm_get_name(prefork_get_name, NULL, NULL, APR_HOOK_MIDDLE);
}
staticconst command_rec prefork_cmds[] = {
LISTEN_COMMANDS,
AP_INIT_TAKE1("StartServers", set_daemons_to_start, NULL, RSRC_CONF, "Number of child processes launched at server startup"),
AP_INIT_TAKE1("MinSpareServers", set_min_free_servers, NULL, RSRC_CONF, "Minimum number of idle children, to handle request spikes"),
AP_INIT_TAKE1("MaxSpareServers", set_max_free_servers, NULL, RSRC_CONF, "Maximum number of idle children"),
AP_INIT_TAKE1("MaxClients", set_max_clients, NULL, RSRC_CONF, "Deprecated name of MaxRequestWorkers"),
AP_INIT_TAKE1("MaxRequestWorkers", set_max_clients, NULL, RSRC_CONF, "Maximum number of children alive at the same time"),
AP_INIT_TAKE1("ServerLimit", set_server_limit, NULL, RSRC_CONF, "Maximum value of MaxRequestWorkers for this run of Apache"),
AP_GRACEFUL_SHUTDOWN_TIMEOUT_COMMAND,
{ NULL }
};
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