/* 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.
*/
#include "apr.h"
#include "apr_portable.h"
#include "apr_strings.h"
#include "apr_thread_proc.h"
#include "apr_signal.h"
#define APR_WANT_STDIO
#define APR_WANT_STRFUNC
#include "apr_want.h"
#if APR_HAVE_UNISTD_H
#include <unistd.h>
#endif
#if APR_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ap_config.h"
#include "httpd.h"
#include "mpm_default.h"
#include "http_main.h"
#include "http_log.h"
#include "http_config.h"
#include "http_core.h" /* for get_remote_host */
#include "http_connection.h"
#include "scoreboard.h"
#include "ap_mpm.h"
#include "util_mutex.h"
#include "unixd.h"
#include "mpm_common.h"
#include "ap_listen.h"
#include "ap_mmn.h"
#include "apr_poll.h"
#include "util_time.h"
#include <stdlib.h>
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#ifdef HAVE_SYS_PROCESSOR_H
#include <sys/processor.h> /* for bindprocessor() */
#endif
#include <signal.h>
#include <sys/times.h>
/* 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
#ifndef HARD_THREAD_LIMIT
#define HARD_THREAD_LIMIT 1
#endif
/* config globals */
static int ap_daemons_to_start=0;
static int ap_daemons_min_free=0;
static int ap_daemons_max_free=0;
static int ap_daemons_limit=0; /* MaxRequestWorkers */
static int server_limit = 0;
static int mpm_state = AP_MPMQ_STARTING;
/* 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
*/
typedef struct prefork_retained_data {
int first_server_limit;
int module_loads;
ap_generation_t my_generation;
int volatile is_graceful; /* set from signal handler */
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;
typedef struct prefork_child_bucket {
ap_pod_t *pod;
ap_listen_rec *listeners;
apr_proc_mutex_t *mutex;
} prefork_child_bucket;
static int num_buckets; /* Number of listeners buckets */
static prefork_child_bucket *all_buckets, /* All listeners buckets */
*my_bucket; /* Current child bucket */
#define MPM_CHILD_PID(i) (ap_scoreboard_image->parent[i].pid)
/* 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.).
*/
static int 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;
static int my_child_num;
#ifdef GPROF
/*
* change directory for gprof to plop the gmon.out file
* configure in httpd.conf:
* GprofDir $RuntimeDir/ -> $ServerRoot/$RuntimeDir/gmon.out
* GprofDir $RuntimeDir/% -> $ServerRoot/$RuntimeDir/gprof.$pid/gmon.out
*/
static void chdir_for_gprof(void)
{
core_server_config *sconf =
ap_get_core_module_config(ap_server_conf->module_config);
char *dir = sconf->gprof_dir;
const char *use_dir;
if(dir) {
apr_status_t res;
char *buf = NULL ;
int len = strlen(sconf->gprof_dir) - 1;
if(*(dir + len) == '%') {
dir[len] = '\0';
buf = ap_append_pid(pconf, dir, "gprof.");
}
use_dir = ap_server_root_relative(pconf, buf ? buf : dir);
res = apr_dir_make(use_dir,
APR_UREAD | APR_UWRITE | APR_UEXECUTE |
APR_GREAD | APR_GEXECUTE |
APR_WREAD | APR_WEXECUTE, pconf);
if(res != APR_SUCCESS && !APR_STATUS_IS_EEXIST(res)) {
ap_log_error(APLOG_MARK, APLOG_ERR, res, ap_server_conf, APLOGNO(00142)
"gprof: error creating directory %s", dir);
}
}
else {
use_dir = ap_runtime_dir_relative(pconf, "");
}
chdir(use_dir);
}
#else
#define chdir_for_gprof()
#endif
static void prefork_note_child_killed(int childnum, pid_t pid,
ap_generation_t gen)
{
AP_DEBUG_ASSERT(childnum != -1); /* no scoreboard squatting with this MPM */
ap_run_child_status(ap_server_conf,
ap_scoreboard_image->parent[childnum].pid,
ap_scoreboard_image->parent[childnum].generation,
childnum, MPM_CHILD_EXITED);
ap_scoreboard_image->parent[childnum].pid = 0;
}
static void prefork_note_child_started(int slot, pid_t pid)
{
ap_scoreboard_image->parent[slot].pid = pid;
ap_run_child_status(ap_server_conf,
ap_scoreboard_image->parent[slot].pid,
retained->my_generation, slot, MPM_CHILD_STARTED);
}
/* a clean exit from a child with proper cleanup */
static void clean_child_exit(int code) __attribute__ ((noreturn));
static void clean_child_exit(int code)
{
mpm_state = AP_MPMQ_STOPPING;
apr_signal(SIGHUP, SIG_IGN);
apr_signal(SIGTERM, SIG_IGN);
if (pchild) {
apr_pool_destroy(pchild);
}
if (one_process) {
prefork_note_child_killed(/* slot */ 0, 0, 0);
}
ap_mpm_pod_close(my_bucket->pod);
chdir_for_gprof();
exit(code);
}
static apr_status_t accept_mutex_on(void)
{
apr_status_t rv = apr_proc_mutex_lock(my_bucket->mutex);
if (rv != APR_SUCCESS) {
const char *msg = "couldn't grab the accept mutex";
if (retained->my_generation !=
ap_scoreboard_image->global->running_generation) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, ap_server_conf, APLOGNO(00143) "%s", msg);
clean_child_exit(0);
}
else {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(00144) "%s", msg);
exit(APEXIT_CHILDFATAL);
}
}
return APR_SUCCESS;
}
static apr_status_t accept_mutex_off(void)
{
apr_status_t rv = apr_proc_mutex_unlock(my_bucket->mutex);
if (rv != APR_SUCCESS) {
const char *msg = "couldn't release the accept mutex";
if (retained->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
static int 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 = mpm_state;
break;
case AP_MPMQ_GENERATION:
*result = retained->my_generation;
break;
default:
*rv = APR_ENOTIMPL;
break;
}
return OK;
}
static const char *prefork_get_name(void)
{
return "prefork";
}
/*****************************************************************
* Connection structures and accounting...
*/
static void just_die(int sig)
{
clean_child_exit(0);
}
/* volatile because they're updated from a signal handler */
static int volatile shutdown_pending;
static int volatile restart_pending;
static int volatile die_now = 0;
static void stop_listening(int sig)
{
mpm_state = AP_MPMQ_STOPPING;
ap_close_listeners_ex(my_bucket->listeners);
/* For a graceful stop, we want the child to exit when done */
die_now = 1;
}
static void sig_term(int sig)
{
if (shutdown_pending == 1) {
/* Um, is this _probably_ not an error, if the user has
* tried to do a shutdown twice quickly, so we won't
* worry about reporting it.
*/
return;
}
mpm_state = AP_MPMQ_STOPPING;
shutdown_pending = 1;
retained->is_graceful = (sig == AP_SIG_GRACEFUL_STOP);
}
/* restart() is the signal handler for SIGHUP and AP_SIG_GRACEFUL
* in the parent process, unless running in ONE_PROCESS mode
*/
static void restart(int sig)
{
if (restart_pending == 1) {
/* Probably not an error - don't bother reporting it */
return;
}
mpm_state = AP_MPMQ_STOPPING;
restart_pending = 1;
retained->is_graceful = (sig == AP_SIG_GRACEFUL);
}
static void set_signals(void)
{
#ifndef NO_USE_SIGACTION
struct sigaction sa;
#endif
if (!one_process) {
ap_fatal_signal_setup(ap_server_conf, pconf);
}
#ifndef NO_USE_SIGACTION
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = sig_term;
if (sigaction(SIGTERM, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00147) "sigaction(SIGTERM)");
#ifdef AP_SIG_GRACEFUL_STOP
if (sigaction(AP_SIG_GRACEFUL_STOP, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00148)
"sigaction(" AP_SIG_GRACEFUL_STOP_STRING ")");
#endif
#ifdef SIGINT
if (sigaction(SIGINT, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00149) "sigaction(SIGINT)");
#endif
#ifdef SIGXCPU
sa.sa_handler = SIG_DFL;
if (sigaction(SIGXCPU, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00150) "sigaction(SIGXCPU)");
#endif
#ifdef SIGXFSZ
/* For systems following the LFS standard, ignoring SIGXFSZ allows
* a write() beyond the 2GB limit to fail gracefully with E2BIG
* rather than terminate the process. */
sa.sa_handler = SIG_IGN;
if (sigaction(SIGXFSZ, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00151) "sigaction(SIGXFSZ)");
#endif
#ifdef SIGPIPE
sa.sa_handler = SIG_IGN;
if (sigaction(SIGPIPE, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00152) "sigaction(SIGPIPE)");
#endif
/* we want to ignore HUPs and AP_SIG_GRACEFUL while we're busy
* processing one
*/
sigaddset(&sa.sa_mask, SIGHUP);
sigaddset(&sa.sa_mask, AP_SIG_GRACEFUL);
sa.sa_handler = restart;
if (sigaction(SIGHUP, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00153) "sigaction(SIGHUP)");
if (sigaction(AP_SIG_GRACEFUL, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00154) "sigaction(" AP_SIG_GRACEFUL_STRING ")");
#else
if (!one_process) {
#ifdef SIGXCPU
apr_signal(SIGXCPU, SIG_DFL);
#endif /* SIGXCPU */
#ifdef SIGXFSZ
apr_signal(SIGXFSZ, SIG_IGN);
#endif /* SIGXFSZ */
}
apr_signal(SIGTERM, sig_term);
#ifdef SIGHUP
apr_signal(SIGHUP, restart);
#endif /* SIGHUP */
#ifdef AP_SIG_GRACEFUL
apr_signal(AP_SIG_GRACEFUL, restart);
#endif /* AP_SIG_GRACEFUL */
#ifdef AP_SIG_GRACEFUL_STOP
apr_signal(AP_SIG_GRACEFUL_STOP, sig_term);
#endif /* AP_SIG_GRACEFUL */
#ifdef SIGPIPE
apr_signal(SIGPIPE, SIG_IGN);
#endif /* SIGPIPE */
#endif
}
/*****************************************************************
* Child process main loop.
* The following vars are static to avoid getting clobbered by longjmp();
* they are really private to child_main.
*/
static int requests_this_child;
static int num_listensocks = 0;
static void child_main(int child_num_arg, int child_bucket)
{
#if APR_HAS_THREADS
apr_thread_t *thd = NULL;
apr_os_thread_t osthd;
#endif
apr_pool_t *ptrans;
apr_allocator_t *allocator;
apr_status_t status;
int i;
ap_listen_rec *lr;
apr_pollset_t *pollset;
ap_sb_handle_t *sbh;
apr_bucket_alloc_t *bucket_alloc;
int last_poll_idx = 0;
const char *lockfile;
mpm_state = AP_MPMQ_STARTING; /* for benefit of any hooks that run as this
* child initializes
*/
my_child_num = child_num_arg;
ap_my_pid = getpid();
requests_this_child = 0;
ap_fatal_signal_child_setup(ap_server_conf);
/* 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");
#if APR_HAS_THREADS
osthd = apr_os_thread_current();
apr_os_thread_put(&thd, &osthd, pchild);
#endif
apr_pool_create(&ptrans, pchild);
apr_pool_tag(ptrans, "transaction");
/* close unused listeners and pods */
for (i = 0; i < 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);
}
ap_run_child_init(pchild, ap_server_conf);
ap_create_sb_handle(&sbh, pchild, my_child_num, 0);
(void) ap_update_child_status(sbh, SERVER_READY, (request_rec *) NULL);
/* 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);
pfd->desc_type = APR_POLL_SOCKET;
pfd->desc.s = lr->sd;
pfd->reqevents = APR_POLLIN;
pfd->client_data = lr;
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;
}
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_pending is set when SIGTERM is received when running
* in single process mode. */
while (!die_now && !shutdown_pending) {
conn_rec *current_conn;
void *csd;
/*
* (Re)initialize this child to a pre-connection state.
*/
apr_pool_clear(ptrans);
if ((ap_max_requests_per_child > 0
&& requests_this_child++ >= ap_max_requests_per_child)) {
clean_child_exit(0);
}
(void) ap_update_child_status(sbh, SERVER_READY, (request_rec *) NULL);
/*
* 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 */
|| (one_process && shutdown_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" */
if (status == APR_EGENERAL) {
/* resource shortage or should-not-occur occured */
clean_child_exit(APEXIT_CHILDSICK);
}
else if (status != APR_SUCCESS) {
continue;
}
/*
* We now have a connection, so set it up with the appropriate
* socket options, file descriptors, and read/write buffers.
*/
current_conn = ap_run_create_connection(ptrans, ap_server_conf, csd, my_child_num, sbh, bucket_alloc);
if (current_conn) {
#if APR_HAS_THREADS
current_conn->current_thread = thd;
#endif
ap_process_connection(current_conn, csd);
ap_lingering_close(current_conn);
}
/* 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;
}
else if (retained->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);
}
static int make_child(server_rec *s, int slot, int bucket)
{
int pid;
if (slot + 1 > retained->max_daemons_limit) {
retained->max_daemons_limit = slot + 1;
}
if (one_process) {
my_bucket = &all_buckets[0];
apr_signal(SIGHUP, sig_term);
/* Don't catch AP_SIG_GRACEFUL in ONE_PROCESS mode :) */
apr_signal(SIGINT, sig_term);
#ifdef SIGQUIT
apr_signal(SIGQUIT, SIG_DFL);
#endif
apr_signal(SIGTERM, sig_term);
prefork_note_child_started(slot, getpid());
child_main(slot, 0);
/* NOTREACHED */
ap_assert(0);
return -1;
}
(void) ap_update_child_status_from_indexes(slot, 0, SERVER_STARTING,
(request_rec *) NULL);
#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) {
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-condition in signals
* handling when httpd is runnning 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);
}
ap_scoreboard_image->parent[slot].bucket = bucket;
prefork_note_child_started(slot, pid);
return 0;
}
/* start up a bunch of children */
static void 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, i % num_buckets) < 0) {
break;
}
--number_to_start;
}
}
static void perform_idle_server_maintenance(apr_pool_t *p)
{
static int bucket_make_child_record = -1;
static int bucket_kill_child_record = -1;
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;
/* initialize the free_list */
free_length = 0;
idle_count = 0;
last_non_dead = -1;
total_non_dead = 0;
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) {
/* 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) % num_buckets;
ap_mpm_pod_signal(all_buckets[bucket_kill_child_record].pod);
retained->idle_spawn_rate = 1;
}
else if (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) {
bucket_make_child_record++;
bucket_make_child_record %= num_buckets;
make_child(ap_server_conf, free_slots[i],
bucket_make_child_record);
}
/* 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;
}
else if (retained->idle_spawn_rate < MAX_SPAWN_RATE) {
retained->idle_spawn_rate *= 2;
}
}
}
else {
retained->idle_spawn_rate = 1;
}
}
/*****************************************************************
* Executive routines.
*/
static int 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->is_graceful) {
if (ap_run_pre_mpm(s->process->pool, SB_SHARED) != OK) {
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->my_generation;
}
restart_pending = shutdown_pending = 0;
set_signals();
if (one_process) {
AP_MONCONTROL(1);
make_child(ap_server_conf, 0, 0);
/* NOTREACHED */
ap_assert(0);
return !OK;
}
/* Don't thrash since num_buckets depends on the
* system and the number of online CPU cores...
*/
if (ap_daemons_limit < num_buckets)
ap_daemons_limit = num_buckets;
if (ap_daemons_to_start < num_buckets)
ap_daemons_to_start = num_buckets;
if (ap_daemons_min_free < num_buckets)
ap_daemons_min_free = num_buckets;
if (ap_daemons_max_free < ap_daemons_min_free + num_buckets)
ap_daemons_max_free = ap_daemons_min_free + 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->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
*/
retained->hold_off_on_exponential_spawning = 10;
}
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00163)
"%s configured -- resuming normal operations",
ap_get_server_description());
ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf, APLOGNO(00164)
"Server built: %s", ap_get_server_built());
ap_log_command_line(plog, s);
ap_log_common(s);
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(00165)
"Accept mutex: %s (default: %s)",
(all_buckets[0].mutex)
? apr_proc_mutex_name(all_buckets[0].mutex)
: "none",
apr_proc_mutex_defname());
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, ap_server_conf);
/* 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->my_generation) {
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;
}
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,
ap_get_scoreboard_process(child_slot)->bucket);
--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 (retained->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, 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;
}
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);
}
mpm_state = AP_MPMQ_STOPPING;
if (shutdown_pending && !retained->is_graceful) {
/* 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;
} 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 */
for (i = 0; i < 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);
/* cleanup pid file */
ap_remove_pid(pconf, ap_pid_fname);
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00170)
"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(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 (!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 */
apr_signal(SIGHUP, SIG_IGN);
apr_signal(AP_SIG_GRACEFUL, SIG_IGN);
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->my_generation;
ap_scoreboard_image->global->running_generation = retained->my_generation;
if (retained->is_graceful) {
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00171)
"Graceful restart requested, doing restart");
/* kill off the idle ones */
for (i = 0; i < 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.
*/
static int 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->module_loads == 1) {
startup = 1;
level_flags |= APLOG_STARTUP;
}
if ((num_listensocks = ap_setup_listeners(ap_server_conf)) < 1) {
ap_log_error(APLOG_MARK, APLOG_ALERT | level_flags, 0,
(startup ? NULL : s),
"no listening sockets available, shutting down");
return DONE;
}
if (one_process) {
num_buckets = 1;
}
else if (!retained->is_graceful) { /* Preserve the number of buckets
on graceful restarts. */
num_buckets = 0;
}
if ((rv = ap_duplicate_listeners(pconf, ap_server_conf,
&listen_buckets, &num_buckets))) {
ap_log_error(APLOG_MARK, APLOG_CRIT | level_flags, rv,
(startup ? NULL : s),
"could not duplicate listeners");
return DONE;
}
all_buckets = apr_pcalloc(pconf, num_buckets *
sizeof(prefork_child_bucket));
for (i = 0; i < num_buckets; i++) {
if (!one_process && /* no POD in one_process mode */
(rv = ap_mpm_pod_open(pconf, &all_buckets[i].pod))) {
ap_log_error(APLOG_MARK, APLOG_CRIT | level_flags, rv,
(startup ? NULL : s),
"could not open pipe-of-death");
return DONE;
}
/* Initialize cross-process accept lock (safe accept needed only) */
if ((rv = SAFE_ACCEPT((apr_snprintf(id, sizeof id, "%i", i),
ap_proc_mutex_create(&all_buckets[i].mutex,
NULL, AP_ACCEPT_MUTEX_TYPE,
id, s, pconf, 0))))) {
ap_log_error(APLOG_MARK, APLOG_CRIT | level_flags, rv,
(startup ? NULL : s),
"could not create accept mutex");
return DONE;
}
all_buckets[i].listeners = listen_buckets[i];
}
return OK;
}
static int prefork_pre_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp)
{
int no_detach, debug, foreground;
apr_status_t rv;
const char *userdata_key = "mpm_prefork_module";
mpm_state = AP_MPMQ_STARTING;
debug = ap_exists_config_define("DEBUG");
if (debug) {
foreground = one_process = 1;
no_detach = 0;
}
else
{
no_detach = ap_exists_config_define("NO_DETACH");
one_process = ap_exists_config_define("ONE_PROCESS");
foreground = ap_exists_config_define("FOREGROUND");
}
ap_mutex_register(p, AP_ACCEPT_MUTEX_TYPE, NULL, APR_LOCK_DEFAULT, 0);
/* sigh, want this only the second time around */
retained = ap_retained_data_get(userdata_key);
if (!retained) {
retained = ap_retained_data_create(userdata_key, sizeof(*retained));
retained->max_daemons_limit = -1;
retained->idle_spawn_rate = 1;
}
++retained->module_loads;
if (retained->module_loads == 2) {
if (!one_process && !foreground) {
/* before we detach, setup crash handlers to log to errorlog */
ap_fatal_signal_setup(ap_server_conf, 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;
}
}
}
parent_pid = ap_my_pid = getpid();
ap_listen_pre_config();
ap_daemons_to_start = DEFAULT_START_DAEMON;
ap_daemons_min_free = DEFAULT_MIN_FREE_DAEMON;
ap_daemons_max_free = DEFAULT_MAX_FREE_DAEMON;
server_limit = DEFAULT_SERVER_LIMIT;
ap_daemons_limit = server_limit;
ap_extended_status = 0;
return OK;
}
static int prefork_check_config(apr_pool_t *p, apr_pool_t *plog,
apr_pool_t *ptemp, server_rec *s)
{
int startup = 0;
/* the reverse of pre_config, we want this only the first time around */
if (retained->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", server_limit);
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL,
" %d servers, decreasing to %d.",
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;
}
else if (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;
}
else if (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", ap_daemons_limit);
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL,
" %d servers, decreasing MaxRequestWorkers to %d.",
server_limit, server_limit);
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL,
" To increase, please see the ServerLimit "
"directive.");
} 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;
}
else if (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", ap_daemons_min_free);
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL,
" to avoid almost certain server failure.");
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL,
" Please read the documentation.");
} 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;
}
static void 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.
*/
static const char *const aszSucc[] = {"core.c", NULL};
ap_force_set_tz(p);
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);
}
static const char *set_daemons_to_start(cmd_parms *cmd, void *dummy, const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
ap_daemons_to_start = atoi(arg);
return NULL;
}
static const char *set_min_free_servers(cmd_parms *cmd, void *dummy, const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
ap_daemons_min_free = atoi(arg);
return NULL;
}
static const char *set_max_free_servers(cmd_parms *cmd, void *dummy, const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
ap_daemons_max_free = atoi(arg);
return NULL;
}
static const char *set_max_clients (cmd_parms *cmd, void *dummy, const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
if (!strcasecmp(cmd->cmd->name, "MaxClients")) {
ap_log_error(APLOG_MARK, APLOG_INFO, 0, NULL, APLOGNO(00188)
"MaxClients is deprecated, use MaxRequestWorkers "
"instead.");
}
ap_daemons_limit = atoi(arg);
return NULL;
}
static const char *set_server_limit (cmd_parms *cmd, void *dummy, const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
server_limit = atoi(arg);
return NULL;
}
static const 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 }
};
AP_DECLARE_MODULE(mpm_prefork) = {
MPM20_MODULE_STUFF,
NULL, /* hook to run before apache parses args */
NULL, /* create per-directory config structure */
NULL, /* merge per-directory config structures */
NULL, /* create per-server config structure */
NULL, /* merge per-server config structures */
prefork_cmds, /* command apr_table_t */
prefork_hooks, /* register hooks */
};