diff options
Diffstat (limited to 'rubbos/app/httpd-2.0.64/server/mpm/prefork/prefork.c')
| -rw-r--r-- | rubbos/app/httpd-2.0.64/server/mpm/prefork/prefork.c | 1355 |
1 files changed, 1355 insertions, 0 deletions
diff --git a/rubbos/app/httpd-2.0.64/server/mpm/prefork/prefork.c b/rubbos/app/httpd-2.0.64/server/mpm/prefork/prefork.c new file mode 100644 index 00000000..8667b4ab --- /dev/null +++ b/rubbos/app/httpd-2.0.64/server/mpm/prefork/prefork.c @@ -0,0 +1,1355 @@ +/* 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 + +#define CORE_PRIVATE + +#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 "unixd.h" +#include "mpm_common.h" +#include "ap_listen.h" +#include "ap_mmn.h" +#include "apr_poll.h" + +#ifdef HAVE_BSTRING_H +#include <bstring.h> /* for IRIX, FD_SET calls bzero() */ +#endif +#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 20000 +#endif + +#ifndef HARD_THREAD_LIMIT +#define HARD_THREAD_LIMIT 1 +#endif + +/* config globals */ + +int ap_threads_per_child=0; /* Worker threads per child */ +static apr_proc_mutex_t *accept_mutex; +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; /* MaxClients */ +static int server_limit = DEFAULT_SERVER_LIMIT; +static int first_server_limit; +static int changed_limit_at_restart; +static int mpm_state = AP_MPMQ_STARTING; +static ap_pod_t *pod; + +/* + * The max child slot ever assigned, preserved across restarts. Necessary + * to deal with MaxClients changes across AP_SIG_GRACEFUL restarts. We + * use this value to optimize routines that have to scan the entire scoreboard. + */ +int ap_max_daemons_limit = -1; +server_rec *ap_server_conf; + +/* 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; +#ifndef MULTITHREAD +static int my_child_num; +#endif +ap_generation_t volatile ap_my_generation=0; + +#ifdef TPF +int tpf_child = 0; +char tpf_server_name[INETD_SERVNAME_LENGTH+1]; +#endif /* TPF */ + +static int die_now = 0; + +#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_module_config(ap_server_conf->module_config, &core_module); + char *dir = sconf->gprof_dir; + const char *use_dir; + + if(dir) { + apr_status_t res; + char buf[512]; + int len = strlen(sconf->gprof_dir) - 1; + if(*(dir + len) == '%') { + dir[len] = '\0'; + apr_snprintf(buf, sizeof(buf), "%sgprof.%d", dir, (int)getpid()); + } + use_dir = ap_server_root_relative(pconf, buf[0] ? buf : dir); + res = apr_dir_make(use_dir, 0755, pconf); + if(res != APR_SUCCESS && !APR_STATUS_IS_EEXIST(res)) { + ap_log_error(APLOG_MARK, APLOG_ERR, errno, ap_server_conf, + "gprof: error creating directory %s", dir); + } + } + else { + use_dir = ap_server_root_relative(pconf, DEFAULT_REL_RUNTIMEDIR); + } + + chdir(use_dir); +} +#else +#define chdir_for_gprof() +#endif + +/* XXX - I don't know if TPF will ever use this module or not, so leave + * the ap_check_signals calls in but disable them - manoj */ +#define ap_check_signals() + +/* 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; + + if (pchild) { + apr_pool_destroy(pchild); + } + ap_mpm_pod_close(pod); + chdir_for_gprof(); + exit(code); +} + +static void accept_mutex_on(void) +{ + apr_status_t rv = apr_proc_mutex_lock(accept_mutex); + if (rv != APR_SUCCESS) { + const char *msg = "couldn't grab the accept mutex"; + + if (ap_my_generation != + ap_scoreboard_image->global->running_generation) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, NULL, msg); + clean_child_exit(0); + } + else { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, NULL, msg); + exit(APEXIT_CHILDFATAL); + } + } +} + +static void accept_mutex_off(void) +{ + apr_status_t rv = apr_proc_mutex_unlock(accept_mutex); + if (rv != APR_SUCCESS) { + const char *msg = "couldn't release the accept mutex"; + + if (ap_my_generation != + ap_scoreboard_image->global->running_generation) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, NULL, 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, NULL, msg); + exit(APEXIT_CHILDFATAL); + } + } +} + +/* 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) do {if (ap_listeners->next) {stmt;}} while(0) +#else +#define SAFE_ACCEPT(stmt) do {stmt;} while(0) +#endif + +AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result) +{ + switch(query_code){ + case AP_MPMQ_MAX_DAEMON_USED: + *result = ap_daemons_limit; + return APR_SUCCESS; + case AP_MPMQ_IS_THREADED: + *result = AP_MPMQ_NOT_SUPPORTED; + return APR_SUCCESS; + case AP_MPMQ_IS_FORKED: + *result = AP_MPMQ_DYNAMIC; + return APR_SUCCESS; + case AP_MPMQ_HARD_LIMIT_DAEMONS: + *result = server_limit; + return APR_SUCCESS; + case AP_MPMQ_HARD_LIMIT_THREADS: + *result = HARD_THREAD_LIMIT; + return APR_SUCCESS; + case AP_MPMQ_MAX_THREADS: + *result = 0; + return APR_SUCCESS; + case AP_MPMQ_MIN_SPARE_DAEMONS: + *result = ap_daemons_min_free; + return APR_SUCCESS; + case AP_MPMQ_MIN_SPARE_THREADS: + *result = 0; + return APR_SUCCESS; + case AP_MPMQ_MAX_SPARE_DAEMONS: + *result = ap_daemons_max_free; + return APR_SUCCESS; + case AP_MPMQ_MAX_SPARE_THREADS: + *result = 0; + return APR_SUCCESS; + case AP_MPMQ_MAX_REQUESTS_DAEMON: + *result = ap_max_requests_per_child; + return APR_SUCCESS; + case AP_MPMQ_MAX_DAEMONS: + *result = server_limit; + return APR_SUCCESS; + case AP_MPMQ_MPM_STATE: + *result = mpm_state; + return APR_SUCCESS; + } + return APR_ENOTIMPL; +} + +#if defined(NEED_WAITPID) +/* + Systems without a real waitpid sometimes lose a child's exit while waiting + for another. Search through the scoreboard for missing children. + */ +int reap_children(int *exitcode, apr_exit_why_e *status) +{ + int n, pid; + + for (n = 0; n < ap_max_daemons_limit; ++n) { + if (ap_scoreboard_image->servers[n][0].status != SERVER_DEAD && + kill((pid = ap_scoreboard_image->parent[n].pid), 0) == -1) { + ap_update_child_status_from_indexes(n, 0, SERVER_DEAD, NULL); + /* just mark it as having a successful exit status */ + *status = APR_PROC_EXIT; + *exitcode = 0; + return(pid); + } + } + return 0; +} +#endif + +/***************************************************************** + * Connection structures and accounting... + */ + +static void just_die(int sig) +{ + clean_child_exit(0); +} + +/* volatile just in case */ +static int volatile shutdown_pending; +static int volatile restart_pending; +static int volatile is_graceful; + +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; + } + shutdown_pending = 1; +} + +/* 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; + } + restart_pending = 1; + 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, "sigaction(SIGTERM)"); +#ifdef SIGINT + if (sigaction(SIGINT, &sa, NULL) < 0) + ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "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, "sigaction(SIGXCPU)"); +#endif +#ifdef SIGXFSZ + sa.sa_handler = SIG_DFL; + if (sigaction(SIGXFSZ, &sa, NULL) < 0) + ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "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, "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, "sigaction(SIGHUP)"); + if (sigaction(AP_SIG_GRACEFUL, &sa, NULL) < 0) + ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(" AP_SIG_GRACEFUL_STRING ")"); +#else + if (!one_process) { +#ifdef SIGXCPU + apr_signal(SIGXCPU, SIG_DFL); +#endif /* SIGXCPU */ +#ifdef SIGXFSZ + apr_signal(SIGXFSZ, SIG_DFL); +#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 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 ap_listen_rec *listensocks; + +int ap_graceful_stop_signalled(void) +{ + /* not ever called anymore... */ + return 0; +} + + +static void child_main(int child_num_arg) +{ + apr_pool_t *ptrans; + apr_allocator_t *allocator; + conn_rec *current_conn; + apr_status_t status = APR_EINIT; + int i; + ap_listen_rec *lr; + int curr_pollfd, last_pollfd = 0; + apr_pollfd_t *pollset; + int offset; + void *csd; + ap_sb_handle_t *sbh; + apr_status_t rv; + apr_bucket_alloc_t *bucket_alloc; + + 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(); + csd = NULL; + 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_create(&ptrans, pchild); + apr_pool_tag(ptrans, "transaction"); + + /* needs to be done before we switch UIDs so we have permissions */ + ap_reopen_scoreboard(pchild, NULL, 0); + rv = apr_proc_mutex_child_init(&accept_mutex, ap_lock_fname, pchild); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, + "Couldn't initialize cross-process lock in child"); + clean_child_exit(APEXIT_CHILDFATAL); + } + + if (unixd_setup_child()) { + 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 */ + listensocks = apr_pcalloc(pchild, + sizeof(*listensocks) * (num_listensocks)); + for (lr = ap_listeners, i = 0; i < num_listensocks; lr = lr->next, i++) { + listensocks[i].accept_func = lr->accept_func; + listensocks[i].sd = lr->sd; + } + + pollset = apr_palloc(pchild, sizeof(*pollset) * num_listensocks); + pollset[0].p = pchild; + for (i = 0; i < num_listensocks; i++) { + pollset[i].desc.s = listensocks[i].sd; + pollset[i].desc_type = APR_POLL_SOCKET; + pollset[i].reqevents = APR_POLLIN; + } + + mpm_state = AP_MPMQ_RUNNING; + + bucket_alloc = apr_bucket_alloc_create(pchild); + + while (!die_now) { + /* + * (Re)initialize this child to a pre-connection state. + */ + + current_conn = NULL; + + 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) { + offset = 0; + } + else { + /* multiple listening sockets - need to poll */ + for (;;) { + apr_status_t ret; + apr_int32_t n; + + ret = apr_poll(pollset, num_listensocks, &n, -1); + if (ret != APR_SUCCESS) { + if (APR_STATUS_IS_EINTR(ret)) { + 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, ret, ap_server_conf, + "apr_poll: (listen)"); + clean_child_exit(1); + } + /* find a listener */ + curr_pollfd = last_pollfd; + do { + curr_pollfd++; + if (curr_pollfd >= num_listensocks) { + curr_pollfd = 0; + } + /* XXX: Should we check for POLLERR? */ + if (pollset[curr_pollfd].rtnevents & APR_POLLIN) { + last_pollfd = curr_pollfd; + offset = curr_pollfd; + goto got_fd; + } + } while (curr_pollfd != last_pollfd); + + continue; + } + } + got_fd: + /* if we accept() something we don't want to die, so we have to + * defer the exit + */ + status = listensocks[offset].accept_func(&csd, + &listensocks[offset], ptrans); + SAFE_ACCEPT(accept_mutex_off()); /* unlock after "accept" */ + + if (status == APR_EGENERAL) { + /* resource shortage or should-not-occur occured */ + clean_child_exit(1); + } + 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) { + 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(pod) == APR_SUCCESS) { /* selected as idle? */ + die_now = 1; + } + else if (ap_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; + } + } + clean_child_exit(0); +} + + +static int make_child(server_rec *s, int slot) +{ + int pid; + + if (slot + 1 > ap_max_daemons_limit) { + ap_max_daemons_limit = slot + 1; + } + + if (one_process) { + apr_signal(SIGHUP, just_die); + /* Don't catch AP_SIG_GRACEFUL in ONE_PROCESS mode :) */ + apr_signal(SIGINT, just_die); +#ifdef SIGQUIT + apr_signal(SIGQUIT, SIG_DFL); +#endif + apr_signal(SIGTERM, just_die); + child_main(slot); + } + + (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(unixd_config.user_name)) == -1) { +#elif defined(TPF) + if ((pid = os_fork(s, slot)) == -1) { +#else + if ((pid = fork()) == -1) { +#endif + ap_log_error(APLOG_MARK, APLOG_ERR, errno, s, "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) { +#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_WARNING, errno, + ap_server_conf, "processor unbind failed %d", status); + } +#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); + /* The child process doesn't do anything for AP_SIG_GRACEFUL. + * Instead, the pod is used for signalling graceful restart. + */ + apr_signal(AP_SIG_GRACEFUL, SIG_IGN); + child_main(slot); + } + + ap_scoreboard_image->parent[slot].pid = 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; + } +} + + +/* + * 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. + */ +static int idle_spawn_rate = 1; +#ifndef MAX_SPAWN_RATE +#define MAX_SPAWN_RATE (32) +#endif +static int hold_off_on_exponential_spawning; + +static void perform_idle_server_maintenance(apr_pool_t *p) +{ + int i; + int to_kill; + 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; + + to_kill = -1; + idle_count = 0; + last_non_dead = -1; + total_non_dead = 0; + + for (i = 0; i < ap_daemons_limit; ++i) { + int status; + + if (i >= ap_max_daemons_limit && free_length == 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 < 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; + /* always kill the highest numbered child if we have to... + * no really well thought out reason ... other than observing + * the server behaviour under linux where lower numbered children + * tend to service more hits (and hence are more likely to have + * their data in cpu caches). + */ + to_kill = i; + } + + ++total_non_dead; + last_non_dead = i; + } + } + ap_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 + */ + ap_mpm_pod_signal(pod); + 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 */ + static int reported = 0; + + if (!reported) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, + "server reached MaxClients setting, consider" + " raising the MaxClients setting"); + reported = 1; + } + idle_spawn_rate = 1; + } + else { + if (idle_spawn_rate >= 8) { + ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf, + "server seems busy, (you may need " + "to increase StartServers, or Min/MaxSpareServers), " + "spawning %d children, there are %d idle, and " + "%d total children", idle_spawn_rate, + idle_count, total_non_dead); + } + for (i = 0; i < free_length; ++i) { +#ifdef TPF + if (make_child(ap_server_conf, free_slots[i]) == -1) { + if(free_length == 1) { + shutdown_pending = 1; + ap_log_error(APLOG_MARK, APLOG_EMERG, 0, ap_server_conf, + "No active child processes: shutting down"); + } + } +#else + make_child(ap_server_conf, free_slots[i]); +#endif /* TPF */ + } + /* 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 (hold_off_on_exponential_spawning) { + --hold_off_on_exponential_spawning; + } + else if (idle_spawn_rate < MAX_SPAWN_RATE) { + idle_spawn_rate *= 2; + } + } + } + else { + idle_spawn_rate = 1; + } +} + +/***************************************************************** + * Executive routines. + */ + +int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) +{ + int index; + int remaining_children_to_start; + apr_status_t rv; + + ap_log_pid(pconf, ap_pid_fname); + + first_server_limit = server_limit; + if (changed_limit_at_restart) { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, + "WARNING: Attempt to change ServerLimit " + "ignored during restart"); + changed_limit_at_restart = 0; + } + + /* Initialize cross-process accept lock */ + ap_lock_fname = apr_psprintf(_pconf, "%s.%" APR_PID_T_FMT, + ap_server_root_relative(_pconf, ap_lock_fname), + ap_my_pid); + + rv = apr_proc_mutex_create(&accept_mutex, ap_lock_fname, + ap_accept_lock_mech, _pconf); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s, + "Couldn't create accept lock"); + mpm_state = AP_MPMQ_STOPPING; + return 1; + } + +#if APR_USE_SYSVSEM_SERIALIZE + if (ap_accept_lock_mech == APR_LOCK_DEFAULT || + ap_accept_lock_mech == APR_LOCK_SYSVSEM) { +#else + if (ap_accept_lock_mech == APR_LOCK_SYSVSEM) { +#endif + rv = unixd_set_proc_mutex_perms(accept_mutex); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s, + "Couldn't set permissions on cross-process lock; " + "check User and Group directives"); + mpm_state = AP_MPMQ_STOPPING; + return 1; + } + } + + if (!is_graceful) { + if (ap_run_pre_mpm(s->process->pool, SB_SHARED) != OK) { + mpm_state = AP_MPMQ_STOPPING; + return 1; + } + /* fix the generation number in the global score; we just got a new, + * cleared scoreboard + */ + ap_scoreboard_image->global->running_generation = ap_my_generation; + } + + set_signals(); + + if (one_process) { + AP_MONCONTROL(1); + } + + if (ap_daemons_max_free < ap_daemons_min_free + 1) /* Don't thrash... */ + ap_daemons_max_free = ap_daemons_min_free + 1; + + /* If we're doing a graceful_restart then we're going to see a lot + * of children exiting immediately when we get into the main loop + * below (because we just sent them AP_SIG_GRACEFUL). This happens pretty + * rapidly... and for each one that exits we'll start a new one until + * we reach at least daemons_min_free. But we may be permitted to + * start more than that, so we'll just keep track of how many we're + * supposed to start up without the 1 second penalty between each fork. + */ + remaining_children_to_start = ap_daemons_to_start; + if (remaining_children_to_start > ap_daemons_limit) { + remaining_children_to_start = ap_daemons_limit; + } + if (!is_graceful) { + startup_children(remaining_children_to_start); + remaining_children_to_start = 0; + } + else { + /* give the system some time to recover before kicking into + * exponential mode */ + hold_off_on_exponential_spawning = 10; + } + + ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, + "%s configured -- resuming normal operations", + ap_get_server_version()); + ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf, + "Server built: %s", ap_get_server_built()); +#ifdef AP_MPM_WANT_SET_ACCEPT_LOCK_MECH + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, + "AcceptMutex: %s (default: %s)", + apr_proc_mutex_name(accept_mutex), + apr_proc_mutex_defname()); +#endif + restart_pending = shutdown_pending = 0; + + mpm_state = AP_MPMQ_RUNNING; + + while (!restart_pending && !shutdown_pending) { + int child_slot; + apr_exit_why_e exitwhy; + int status, processed_status; + /* this is a memory leak, but I'll fix it later. */ + apr_proc_t pid; + + ap_wait_or_timeout(&exitwhy, &status, &pid, pconf); + + /* XXX: if it takes longer than 1 second for all our children + * to start up and get into IDLE state then we may spawn an + * extra child + */ + if (pid.pid != -1) { + processed_status = ap_process_child_status(&pid, exitwhy, status); + if (processed_status == APEXIT_CHILDFATAL) { + mpm_state = AP_MPMQ_STOPPING; + return 1; + } + + /* non-fatal death... note that it's gone in the scoreboard. */ + child_slot = find_child_by_pid(&pid); + if (child_slot >= 0) { + (void) ap_update_child_status_from_indexes(child_slot, 0, SERVER_DEAD, + (request_rec *) NULL); + if (processed_status == APEXIT_CHILDSICK) { + /* child detected a resource shortage (E[NM]FILE, ENOBUFS, etc) + * cut the fork rate to the minimum + */ + idle_spawn_rate = 1; + } + else if (remaining_children_to_start + && child_slot < ap_daemons_limit) { + /* we're still doing a 1-for-1 replacement of dead + * children with new children + */ + make_child(ap_server_conf, child_slot); + --remaining_children_to_start; + } +#if APR_HAS_OTHER_CHILD + } + else if (apr_proc_other_child_read(&pid, status) == 0) { + /* handled */ +#endif + } + else if (is_graceful) { + /* Great, we've probably just lost a slot in the + * scoreboard. Somehow we don't know about this + * child. + */ + ap_log_error(APLOG_MARK, APLOG_WARNING, + 0, ap_server_conf, + "long lost child came home! (pid %ld)", (long)pid.pid); + } + /* Don't perform idle maintenance when a child dies, + * only do it when there's a timeout. Remember only a + * finite number of children can die, and it's pretty + * pathological for a lot to die suddenly. + */ + continue; + } + else if (remaining_children_to_start) { + /* we hit a 1 second timeout in which none of the previous + * generation of children needed to be reaped... so assume + * they're all done, and pick up the slack if any is left. + */ + startup_children(remaining_children_to_start); + remaining_children_to_start = 0; + /* In any event we really shouldn't do the code below because + * few of the servers we just started are in the IDLE state + * yet, so we'd mistakenly create an extra server. + */ + continue; + } + + perform_idle_server_maintenance(pconf); +#ifdef TPF + shutdown_pending = os_check_server(tpf_server_name); + ap_check_signals(); + sleep(1); +#endif /*TPF */ + } + + mpm_state = AP_MPMQ_STOPPING; + + if (shutdown_pending) { + /* Time to gracefully shut down: + * Kill child processes, tell them to call child_exit, etc... + */ + if (unixd_killpg(getpgrp(), SIGTERM) < 0) { + ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGTERM"); + } + ap_reclaim_child_processes(1); /* Start with SIGTERM */ + + /* cleanup pid file on normal shutdown */ + { + const char *pidfile = NULL; + pidfile = ap_server_root_relative (pconf, ap_pid_fname); + if ( pidfile != NULL && unlink(pidfile) == 0) + ap_log_error(APLOG_MARK, APLOG_INFO, + 0, ap_server_conf, + "removed PID file %s (pid=%ld)", + pidfile, (long)getpid()); + } + + ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, + "caught SIGTERM, shutting down"); + return 1; + } + + /* we've been told to restart */ + apr_signal(SIGHUP, SIG_IGN); + if (one_process) { + /* not worth thinking about */ + return 1; + } + + /* advance to the next generation */ + /* XXX: we really need to make sure this new generation number isn't in + * use by any of the children. + */ + ++ap_my_generation; + ap_scoreboard_image->global->running_generation = ap_my_generation; + + if (is_graceful) { + ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, + "Graceful restart requested, doing restart"); + + /* kill off the idle ones */ + ap_mpm_pod_killpg(pod, ap_max_daemons_limit); + + /* This is mostly for debugging... so that we know what is still + * gracefully dealing with existing request. This will break + * in a very nasty way if we ever have the scoreboard totally + * file-based (no shared memory) + */ + for (index = 0; index < ap_daemons_limit; ++index) { + if (ap_scoreboard_image->servers[index][0].status != SERVER_DEAD) { + ap_scoreboard_image->servers[index][0].status = SERVER_GRACEFUL; + } + } + } + else { + /* Kill 'em off */ + if (unixd_killpg(getpgrp(), SIGHUP) < 0) { + ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGHUP"); + } + ap_reclaim_child_processes(0); /* Not when just starting up */ + ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, + "SIGHUP received. Attempting to restart"); + } + + return 0; +} + +/* This really should be a post_config hook, but the error log is already + * redirected by that point, so we need to do this in the open_logs phase. + */ +static int prefork_open_logs(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s) +{ + apr_status_t rv; + + pconf = p; + ap_server_conf = s; + + if ((num_listensocks = ap_setup_listeners(ap_server_conf)) < 1) { + ap_log_error(APLOG_MARK, APLOG_ALERT|APLOG_STARTUP, 0, + NULL, "no listening sockets available, shutting down"); + return DONE; + } + + if ((rv = ap_mpm_pod_open(pconf, &pod))) { + ap_log_error(APLOG_MARK, APLOG_CRIT|APLOG_STARTUP, rv, NULL, + "Could not open pipe-of-death."); + return DONE; + } + return OK; +} + +static int prefork_pre_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp) +{ + static int restart_num = 0; + int no_detach, debug, foreground; + apr_status_t rv; + + 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"); + } + + /* sigh, want this only the second time around */ + if (restart_num++ == 1) { + is_graceful = 0; + + if (!one_process && !foreground) { + 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, + "apr_proc_detach failed"); + return HTTP_INTERNAL_SERVER_ERROR; + } + } + + parent_pid = ap_my_pid = getpid(); + } + + unixd_pre_config(ptemp); + 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; + ap_daemons_limit = server_limit; + ap_pid_fname = DEFAULT_PIDLOG; + ap_lock_fname = DEFAULT_LOCKFILE; + ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD; + ap_extended_status = 0; +#ifdef AP_MPM_WANT_SET_MAX_MEM_FREE + ap_max_mem_free = APR_ALLOCATOR_MAX_FREE_UNLIMITED; +#endif + + apr_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir)); + + return OK; +} + +static void prefork_hooks(apr_pool_t *p) +{ + /* The prefork open_logs phase 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}; + +#ifdef AUX3 + (void) set42sig(); +#endif + + ap_hook_open_logs(prefork_open_logs, NULL, aszSucc, APR_HOOK_MIDDLE); + /* 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); +} + +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); + if (ap_daemons_min_free <= 0) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: detected MinSpareServers set to non-positive."); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "Resetting to 1 to avoid almost certain Apache failure."); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "Please read the documentation."); + ap_daemons_min_free = 1; + } + + 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; + } + + ap_daemons_limit = atoi(arg); + if (ap_daemons_limit > server_limit) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: MaxClients of %d exceeds ServerLimit value " + "of %d servers,", ap_daemons_limit, server_limit); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " lowering MaxClients to %d. To increase, please " + "see the ServerLimit", server_limit); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " directive."); + ap_daemons_limit = server_limit; + } + else if (ap_daemons_limit < 1) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: Require MaxClients > 0, setting to 1"); + ap_daemons_limit = 1; + } + return NULL; +} + +static const char *set_server_limit (cmd_parms *cmd, void *dummy, const char *arg) +{ + int tmp_server_limit; + + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + if (err != NULL) { + return err; + } + + tmp_server_limit = atoi(arg); + /* you cannot change ServerLimit across a restart; ignore + * any such attempts + */ + if (first_server_limit && + tmp_server_limit != server_limit) { + /* how do we log a message? the error log is a bit bucket at this + * point; we'll just have to set a flag so that ap_mpm_run() + * logs a warning later + */ + changed_limit_at_restart = 1; + return NULL; + } + server_limit = tmp_server_limit; + + if (server_limit > MAX_SERVER_LIMIT) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: ServerLimit of %d exceeds compile time limit " + "of %d servers,", server_limit, MAX_SERVER_LIMIT); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " lowering ServerLimit to %d.", MAX_SERVER_LIMIT); + server_limit = MAX_SERVER_LIMIT; + } + else if (server_limit < 1) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: Require ServerLimit > 0, setting to 1"); + server_limit = 1; + } + return NULL; +} + +static const command_rec prefork_cmds[] = { +UNIX_DAEMON_COMMANDS, +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, + "Maximum number of children alive at the same time"), +AP_INIT_TAKE1("ServerLimit", set_server_limit, NULL, RSRC_CONF, + "Maximum value of MaxClients for this run of Apache"), +{ NULL } +}; + +module AP_MODULE_DECLARE_DATA mpm_prefork_module = { + MPM20_MODULE_STUFF, + ap_mpm_rewrite_args, /* 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 */ +}; |