void ap_relieve_child_processes(void)
{
int i;
extra_process_t *cur_extra;
int max_daemons;
ap_mpm_query(AP_MPMQ_MAX_DAEMON_USED, &max_daemons);
/* now see who is done */
for (i = 0; i < max_daemons; ++i) {
pid_t pid = MPM_CHILD_PID(i);
if (pid == 0) {
continue; /* not every scoreboard entry is in use */
}
if (reclaim_one_pid(pid, DO_NOTHING)) {
MPM_NOTE_CHILD_KILLED(i);
}
}
cur_extra = extras;
while (cur_extra) {
extra_process_t *next = cur_extra->next;
if (reclaim_one_pid(cur_extra->pid, DO_NOTHING)) {
AP_DEBUG_ASSERT(1 == ap_unregister_extra_mpm_process(cur_extra->pid));
}
cur_extra = next;
}
}
int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s)
{
int index;
int remaining_children_to_start;
apr_status_t rv;
ap_log_pid(pconf, ap_pid_fname);
first_server_limit = server_limit;
if (changed_limit_at_restart) {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s,
"WARNING: Attempt to change ServerLimit "
"ignored during restart");
changed_limit_at_restart = 0;
}
/* Initialize cross-process accept lock */
ap_lock_fname = apr_psprintf(_pconf, "%s.%" APR_PID_T_FMT,
ap_server_root_relative(_pconf, ap_lock_fname),
ap_my_pid);
rv = apr_proc_mutex_create(&accept_mutex, ap_lock_fname,
ap_accept_lock_mech, _pconf);
if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s,
"Couldn't create accept lock (%s) (%d)",
ap_lock_fname, ap_accept_lock_mech);
mpm_state = AP_MPMQ_STOPPING;
return 1;
}
#if APR_USE_SYSVSEM_SERIALIZE
if (ap_accept_lock_mech == APR_LOCK_DEFAULT ||
ap_accept_lock_mech == APR_LOCK_SYSVSEM) {
#else
if (ap_accept_lock_mech == APR_LOCK_SYSVSEM) {
#endif
rv = unixd_set_proc_mutex_perms(accept_mutex);
if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s,
"Couldn't set permissions on cross-process lock; "
"check User and Group directives");
mpm_state = AP_MPMQ_STOPPING;
return 1;
}
}
if (!is_graceful) {
if (ap_run_pre_mpm(s->process->pool, SB_SHARED) != OK) {
mpm_state = AP_MPMQ_STOPPING;
return 1;
}
/* fix the generation number in the global score; we just got a new,
* cleared scoreboard
*/
ap_scoreboard_image->global->running_generation = ap_my_generation;
}
set_signals();
if (one_process) {
AP_MONCONTROL(1);
make_child(ap_server_conf, 0);
}
else {
if (ap_daemons_max_free < ap_daemons_min_free + 1) /* Don't thrash... */
ap_daemons_max_free = ap_daemons_min_free + 1;
/* 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 (!is_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
*/
hold_off_on_exponential_spawning = 10;
}
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
"%s configured -- resuming normal operations",
ap_get_server_description());
ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf,
"Server built: %s", ap_get_server_built());
#ifdef AP_MPM_WANT_SET_ACCEPT_LOCK_MECH
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
"AcceptMutex: %s (default: %s)",
apr_proc_mutex_name(accept_mutex),
apr_proc_mutex_defname());
#endif
restart_pending = shutdown_pending = 0;
mpm_state = AP_MPMQ_RUNNING;
while (!restart_pending && !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;
ap_wait_or_timeout(&exitwhy, &status, &pid, pconf);
/* 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);
if (processed_status == APEXIT_CHILDFATAL) {
mpm_state = AP_MPMQ_STOPPING;
return 1;
}
/* non-fatal death... note that it's gone in the scoreboard. */
child_slot = find_child_by_pid(&pid);
if (child_slot >= 0) {
(void) ap_update_child_status_from_indexes(child_slot, 0, SERVER_DEAD,
(request_rec *) NULL);
if (processed_status == APEXIT_CHILDSICK) {
/* child detected a resource shortage (E[NM]FILE, ENOBUFS, etc)
* cut the fork rate to the minimum
*/
idle_spawn_rate = 1;
}
else if (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
}
else if (apr_proc_other_child_alert(&pid, APR_OC_REASON_DEATH, status) == APR_SUCCESS) {
/* handled */
#endif
}
else if (is_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,
"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;
}
else if (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);
#ifdef TPF
shutdown_pending = os_check_server(tpf_server_name);
ap_check_signals();
sleep(1);
#endif /*TPF */
}
} /* one_process */
mpm_state = AP_MPMQ_STOPPING;
if (shutdown_pending && !is_graceful) {
/* Time to shut down:
* Kill child processes, tell them to call child_exit, etc...
*/
if (unixd_killpg(getpgrp(), SIGTERM) < 0) {
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGTERM");
}
ap_reclaim_child_processes(1); /* Start with SIGTERM */
/* cleanup pid file on normal shutdown */
{
const char *pidfile = NULL;
pidfile = ap_server_root_relative (pconf, ap_pid_fname);
if ( pidfile != NULL && unlink(pidfile) == 0)
ap_log_error(APLOG_MARK, APLOG_INFO,
0, ap_server_conf,
"removed PID file %s (pid=%ld)",
pidfile, (long)getpid());
}
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
"caught SIGTERM, shutting down");
return 1;
} else if (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 */
ap_mpm_pod_killpg(pod, ap_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();
/* cleanup pid file */
{
const char *pidfile = NULL;
pidfile = ap_server_root_relative (pconf, ap_pid_fname);
if ( pidfile != NULL && unlink(pidfile) == 0)
ap_log_error(APLOG_MARK, APLOG_INFO,
0, ap_server_conf,
"removed PID file %s (pid=%ld)",
pidfile, (long)getpid());
}
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
"caught " AP_SIG_GRACEFUL_STOP_STRING ", shutting down gracefully");
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 */
shutdown_pending = 0;
do {
/* Pause for a second */
sleep(1);
/* Relieve any children which have now exited */
ap_relieve_child_processes();
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 (!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.
*/
unixd_killpg(getpgrp(), SIGTERM);
return 1;
}
/* we've been told to restart */
apr_signal(SIGHUP, SIG_IGN);
apr_signal(AP_SIG_GRACEFUL, SIG_IGN);
if (one_process) {
/* not worth thinking about */
return 1;
}
/* advance to the next generation */
/* XXX: we really need to make sure this new generation number isn't in
* use by any of the children.
*/
++ap_my_generation;
ap_scoreboard_image->global->running_generation = ap_my_generation;
if (is_graceful) {
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
"Graceful restart requested, doing restart");
/* kill off the idle ones */
ap_mpm_pod_killpg(pod, ap_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 (unixd_killpg(getpgrp(), SIGHUP) < 0) {
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGHUP");
}
ap_reclaim_child_processes(0); /* Not when just starting up */
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
"SIGHUP received. Attempting to restart");
}
return 0;
}
/* This really should be a post_config hook, but the error log is already
* redirected by that point, so we need to do this in the open_logs phase.
*/
static int prefork_open_logs(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s)
{
apr_status_t rv;
pconf = p;
ap_server_conf = s;
if ((num_listensocks = ap_setup_listeners(ap_server_conf)) < 1) {
ap_log_error(APLOG_MARK, APLOG_ALERT|APLOG_STARTUP, 0,
NULL, "no listening sockets available, shutting down");
return DONE;
}
if ((rv = ap_mpm_pod_open(pconf, &pod))) {
ap_log_error(APLOG_MARK, APLOG_CRIT|APLOG_STARTUP, rv, NULL,
"Could not open pipe-of-death.");
return DONE;
}
return OK;
}
void ap_reclaim_child_processes(int terminate)
{
apr_time_t waittime = 1024 * 16;
int i;
extra_process_t *cur_extra;
int not_dead_yet;
int max_daemons;
apr_time_t starttime = apr_time_now();
/* this table of actions and elapsed times tells what action is taken
* at which elapsed time from starting the reclaim
*/
struct {
action_t action;
apr_time_t action_time;
} action_table[] = {
{DO_NOTHING, 0}, /* dummy entry for iterations where we reap
* children but take no action against
* stragglers
*/
{SEND_SIGTERM, apr_time_from_sec(3)},
{SEND_SIGTERM, apr_time_from_sec(5)},
{SEND_SIGTERM, apr_time_from_sec(7)},
{SEND_SIGKILL, apr_time_from_sec(9)},
{GIVEUP, apr_time_from_sec(10)}
};
int cur_action; /* index of action we decided to take this
* iteration
*/
int next_action = 1; /* index of first real action */
ap_mpm_query(AP_MPMQ_MAX_DAEMON_USED, &max_daemons);
do {
apr_sleep(waittime);
/* don't let waittime get longer than 1 second; otherwise, we don't
* react quickly to the last child exiting, and taking action can
* be delayed
*/
waittime = waittime * 4;
if (waittime > apr_time_from_sec(1)) {
waittime = apr_time_from_sec(1);
}
/* see what action to take, if any */
if (action_table[next_action].action_time <= apr_time_now() - starttime) {
cur_action = next_action;
++next_action;
}
else {
cur_action = 0; /* nothing to do */
}
/* now see who is done */
not_dead_yet = 0;
for (i = 0; i < max_daemons; ++i) {
pid_t pid = MPM_CHILD_PID(i);
if (pid == 0) {
continue; /* not every scoreboard entry is in use */
}
if (reclaim_one_pid(pid, action_table[cur_action].action)) {
MPM_NOTE_CHILD_KILLED(i);
}
else {
++not_dead_yet;
}
}
cur_extra = extras;
while (cur_extra) {
extra_process_t *next = cur_extra->next;
if (reclaim_one_pid(cur_extra->pid, action_table[cur_action].action)) {
AP_DEBUG_ASSERT(1 == ap_unregister_extra_mpm_process(cur_extra->pid));
}
else {
++not_dead_yet;
}
cur_extra = next;
}
#if APR_HAS_OTHER_CHILD
apr_proc_other_child_refresh_all(APR_OC_REASON_RESTART);
#endif
} while (not_dead_yet > 0 &&
action_table[cur_action].action != GIVEUP);
}