diff options
Diffstat (limited to 'server/mpm/prefork')
| -rw-r--r-- | server/mpm/prefork/Makefile.in | 1 | ||||
| -rw-r--r-- | server/mpm/prefork/config.m4 | 7 | ||||
| -rw-r--r-- | server/mpm/prefork/config3.m4 | 1 | ||||
| -rw-r--r-- | server/mpm/prefork/mpm_default.h | 51 | ||||
| -rw-r--r-- | server/mpm/prefork/prefork.c | 1563 |
5 files changed, 1623 insertions, 0 deletions
diff --git a/server/mpm/prefork/Makefile.in b/server/mpm/prefork/Makefile.in new file mode 100644 index 0000000..f34af9c --- /dev/null +++ b/server/mpm/prefork/Makefile.in @@ -0,0 +1 @@ +include $(top_srcdir)/build/special.mk diff --git a/server/mpm/prefork/config.m4 b/server/mpm/prefork/config.m4 new file mode 100644 index 0000000..296f834 --- /dev/null +++ b/server/mpm/prefork/config.m4 @@ -0,0 +1,7 @@ +AC_MSG_CHECKING(if prefork MPM supports this platform) +if test $forking_mpms_supported != yes; then + AC_MSG_RESULT(no - This is not a forking platform) +else + AC_MSG_RESULT(yes) + APACHE_MPM_SUPPORTED(prefork, yes, no) +fi diff --git a/server/mpm/prefork/config3.m4 b/server/mpm/prefork/config3.m4 new file mode 100644 index 0000000..25fd8df --- /dev/null +++ b/server/mpm/prefork/config3.m4 @@ -0,0 +1 @@ +APACHE_MPM_MODULE(prefork, $enable_mpm_prefork) diff --git a/server/mpm/prefork/mpm_default.h b/server/mpm/prefork/mpm_default.h new file mode 100644 index 0000000..55b038b --- /dev/null +++ b/server/mpm/prefork/mpm_default.h @@ -0,0 +1,51 @@ +/* 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. + */ + +/** + * @file prefork/mpm_default.h + * @brief Prefork MPM defaults + * + * @defgroup APACHE_MPM_PREFORK Prefork MPM + * @ingroup APACHE_INTERNAL + * @{ + */ + +#ifndef APACHE_MPM_DEFAULT_H +#define APACHE_MPM_DEFAULT_H + +/* Number of servers to spawn off by default --- also, if fewer than + * this free when the caretaker checks, it will spawn more. + */ +#ifndef DEFAULT_START_DAEMON +#define DEFAULT_START_DAEMON 5 +#endif + +/* Maximum number of *free* server processes --- more than this, and + * they will die off. + */ + +#ifndef DEFAULT_MAX_FREE_DAEMON +#define DEFAULT_MAX_FREE_DAEMON 10 +#endif + +/* Minimum --- fewer than this, and more will be created */ + +#ifndef DEFAULT_MIN_FREE_DAEMON +#define DEFAULT_MIN_FREE_DAEMON 5 +#endif + +#endif /* AP_MPM_DEFAULT_H */ +/** @} */ diff --git a/server/mpm/prefork/prefork.c b/server/mpm/prefork/prefork.c new file mode 100644 index 0000000..b5adb57 --- /dev/null +++ b/server/mpm/prefork/prefork.c @@ -0,0 +1,1563 @@ +/* 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 <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; + +/* 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 { + 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; + +typedef struct prefork_child_bucket { + ap_pod_t *pod; + ap_listen_rec *listeners; + apr_proc_mutex_t *mutex; +} prefork_child_bucket; +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_generation_t gen = retained->mpm->my_generation; + ap_scoreboard_image->parent[slot].pid = pid; + ap_scoreboard_image->parent[slot].generation = gen; + ap_run_child_status(ap_server_conf, pid, gen, 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) +{ + retained->mpm->mpm_state = AP_MPMQ_STOPPING; + + apr_signal(SIGHUP, SIG_IGN); + apr_signal(SIGTERM, SIG_IGN); + + if (code == 0) { + ap_run_child_stopping(pchild, 0); + } + + 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->mpm->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->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 + +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 = retained->mpm->mpm_state; + break; + case AP_MPMQ_GENERATION: + *result = retained->mpm->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 it's updated from a signal handler */ +static int volatile die_now = 0; + +static void stop_listening(int sig) +{ + retained->mpm->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; +} + +/***************************************************************** + * 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; + +#if APR_HAS_THREADS +static void child_sigmask(sigset_t *new_mask, sigset_t *old_mask) +{ +#if defined(SIGPROCMASK_SETS_THREAD_MASK) + sigprocmask(SIG_SETMASK, new_mask, old_mask); +#else + pthread_sigmask(SIG_SETMASK, new_mask, old_mask); +#endif +} +#endif + +static void child_main(int child_num_arg, int child_bucket) +{ +#if APR_HAS_THREADS + apr_thread_t *thd = NULL; + sigset_t sig_mask; +#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; + + /* for benefit of any hooks that run as this child initializes */ + retained->mpm->mpm_state = AP_MPMQ_STARTING; + + 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 AP_HAS_THREAD_LOCAL + if (one_process) { + thd = ap_thread_current(); + } + else if ((status = ap_thread_main_create(&thd, pchild))) { + ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf, APLOGNO(10378) + "Couldn't initialize child main thread"); + clean_child_exit(APEXIT_CHILDFATAL); + } +#elif APR_HAS_THREADS + { + apr_os_thread_t osthd = apr_os_thread_current(); + apr_os_thread_put(&thd, &osthd, pchild); + } +#endif +#if APR_HAS_THREADS + ap_assert(thd != NULL); +#endif + + apr_pool_create(&ptrans, pchild); + apr_pool_tag(ptrans, "transaction"); + + /* 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 + + 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; + } + + 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. + */ + + 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 */ + || 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" */ + + if (status == APR_EGENERAL) { + /* resource shortage or should-not-occur occurred */ + 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->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); +} + + +static int make_child(server_rec *s, int slot) +{ + int bucket = slot % retained->mpm->num_buckets; + int pid; + + if (slot + 1 > retained->max_daemons_limit) { + retained->max_daemons_limit = slot + 1; + } + + if (one_process) { + my_bucket = &all_buckets[0]; + + 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) { +#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 */ +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) < 0) { + break; + } + --number_to_start; + } +} + +static void 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; + + /* 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) { + static int 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; + } + 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) { + 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; + } + 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->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; + } + + ap_unixd_mpm_set_signals(pconf, one_process); + + if (one_process) { + AP_MONCONTROL(1); + make_child(ap_server_conf, 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 < 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; + } + + 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_mpm_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()); + + retained->mpm->mpm_state = AP_MPMQ_RUNNING; + + 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; + + 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->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; + } + 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 (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; + } + 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); + } + + 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); + + /* 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 */ + 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; + + if (!retained->mpm->is_ungraceful) { + 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 < 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. + */ +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->mpm->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 !OK; + } + + if (one_process) { + retained->mpm->num_buckets = 1; + } + else if (!retained->mpm->was_graceful) { + /* Preserve the number of buckets on graceful restarts. */ + retained->mpm->num_buckets = 0; + } + if ((rv = ap_duplicate_listeners(pconf, ap_server_conf, + &listen_buckets, &retained->mpm->num_buckets))) { + ap_log_error(APLOG_MARK, APLOG_CRIT | level_flags, rv, + (startup ? NULL : s), + "could not duplicate listeners"); + return !OK; + } + all_buckets = apr_pcalloc(pconf, retained->mpm->num_buckets * + sizeof(prefork_child_bucket)); + for (i = 0; i < retained->mpm->num_buckets; i++) { + if ((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 !OK; + } + /* 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 !OK; + } + 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"; + + 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); + + retained = ap_retained_data_get(userdata_key); + if (!retained) { + retained = ap_retained_data_create(userdata_key, sizeof(*retained)); + retained->mpm = ap_unixd_mpm_get_retained_data(); + retained->idle_spawn_rate = 1; + } + retained->mpm->mpm_state = AP_MPMQ_STARTING; + if (retained->mpm->baton != retained) { + retained->mpm->was_graceful = 0; + retained->mpm->baton = retained; + } + ++retained->mpm->module_loads; + + /* 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; + } + } + } + + 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->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; + } + 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 %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; + } + 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 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; +} + +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_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 */ +}; |