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Diffstat (limited to 'server/mpm/worker/worker.c')
| -rw-r--r-- | server/mpm/worker/worker.c | 2455 |
1 files changed, 2455 insertions, 0 deletions
diff --git a/server/mpm/worker/worker.c b/server/mpm/worker/worker.c new file mode 100644 index 0000000..7b572bd --- /dev/null +++ b/server/mpm/worker/worker.c @@ -0,0 +1,2455 @@ +/* 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. + */ + +/* The purpose of this MPM is to fix the design flaws in the threaded + * model. Because of the way that pthreads and mutex locks interact, + * it is basically impossible to cleanly gracefully shutdown a child + * process if multiple threads are all blocked in accept. This model + * fixes those problems. + */ + +#include "apr.h" +#include "apr_portable.h" +#include "apr_strings.h" +#include "apr_file_io.h" +#include "apr_thread_proc.h" +#include "apr_signal.h" +#include "apr_thread_mutex.h" +#include "apr_proc_mutex.h" +#include "apr_poll.h" + +#include <stdlib.h> + +#define APR_WANT_STRFUNC +#include "apr_want.h" + +#if APR_HAVE_UNISTD_H +#include <unistd.h> +#endif +#if APR_HAVE_SYS_SOCKET_H +#include <sys/socket.h> +#endif +#if APR_HAVE_SYS_WAIT_H +#include <sys/wait.h> +#endif +#ifdef HAVE_SYS_PROCESSOR_H +#include <sys/processor.h> /* for bindprocessor() */ +#endif + +#if !APR_HAS_THREADS +#error The Worker MPM requires APR threads, but they are unavailable. +#endif + +#include "ap_config.h" +#include "httpd.h" +#include "http_main.h" +#include "http_log.h" +#include "http_config.h" /* for read_config */ +#include "http_core.h" /* for get_remote_host */ +#include "http_connection.h" +#include "ap_mpm.h" +#include "mpm_common.h" +#include "ap_listen.h" +#include "scoreboard.h" +#include "mpm_fdqueue.h" +#include "mpm_default.h" +#include "util_mutex.h" +#include "unixd.h" + +#include <signal.h> +#include <limits.h> /* for INT_MAX */ + +/* 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 16 +#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 + +/* Limit on the threads per process. Clients will be locked out if more than + * this * server_limit are needed. + * + * We keep this for one reason 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_THREAD_LIMIT +#define DEFAULT_THREAD_LIMIT 64 +#endif + +/* Admin can't tune ThreadLimit beyond MAX_THREAD_LIMIT. We want + * some sort of compile-time limit to help catch typos. + */ +#ifndef MAX_THREAD_LIMIT +#define MAX_THREAD_LIMIT 20000 +#endif + +/* + * Actual definitions of config globals + */ + +static int threads_per_child = 0; /* Worker threads per child */ +static int ap_daemons_to_start = 0; +static int min_spare_threads = 0; +static int max_spare_threads = 0; +static int ap_daemons_limit = 0; +static int max_workers = 0; +static int server_limit = 0; +static int thread_limit = 0; +static int had_healthy_child = 0; +static int dying = 0; +static int workers_may_exit = 0; +static int start_thread_may_exit = 0; +static int listener_may_exit = 0; +static int requests_this_child; +static int num_listensocks = 0; +static int resource_shortage = 0; +static fd_queue_t *worker_queue; +static fd_queue_info_t *worker_queue_info; +static apr_pollset_t *worker_pollset; + + +/* data retained by worker across load/unload of the module + * allocated on first call to pre-config hook; located on + * subsequent calls to pre-config hook + */ +typedef struct worker_retained_data { + ap_unixd_mpm_retained_data *mpm; + + int first_server_limit; + int first_thread_limit; + int sick_child_detected; + int maxclients_reported; + int near_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 + * maintained per listeners bucket, 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; +} worker_retained_data; +static worker_retained_data *retained; + +typedef struct worker_child_bucket { + ap_pod_t *pod; + ap_listen_rec *listeners; + apr_proc_mutex_t *mutex; +} worker_child_bucket; +static worker_child_bucket *all_buckets, /* All listeners buckets */ + *my_bucket; /* Current child bucket */ + +#define MPM_CHILD_PID(i) (ap_scoreboard_image->parent[i].pid) + +/* The structure used to pass unique initialization info to each thread */ +typedef struct { + int pid; + int tid; + int sd; +} proc_info; + +/* Structure used to pass information to the thread responsible for + * creating the rest of the threads. + */ +typedef struct { + apr_thread_t **threads; + apr_thread_t *listener; + int child_num_arg; + apr_threadattr_t *threadattr; +} thread_starter; + +#define ID_FROM_CHILD_THREAD(c, t) ((c * thread_limit) + t) + +/* The worker MPM respects a couple of runtime flags that can aid + * in debugging. Setting the -DNO_DETACH flag will prevent the root process + * from detaching from its controlling terminal. Additionally, setting + * the -DONE_PROCESS flag (which implies -DNO_DETACH) will get you the + * child_main loop running in the process which originally started up. + * This gives you 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; + +#ifdef DEBUG_SIGSTOP +int raise_sigstop_flags; +#endif + +static apr_pool_t *pconf; /* Pool for config stuff */ +static apr_pool_t *pchild; /* Pool for httpd child stuff */ +static apr_pool_t *pruntime; /* Pool for MPM threads stuff */ + +static pid_t ap_my_pid; /* Linux getpid() doesn't work except in main + thread. Use this instead */ +static pid_t parent_pid; +static apr_os_thread_t *listener_os_thread; + +#ifdef SINGLE_LISTEN_UNSERIALIZED_ACCEPT +#define SAFE_ACCEPT(stmt) (ap_listeners->next ? (stmt) : APR_SUCCESS) +#else +#define SAFE_ACCEPT(stmt) (stmt) +#endif + +/* The LISTENER_SIGNAL signal will be sent from the main thread to the + * listener thread to wake it up for graceful termination (what a child + * process from an old generation does when the admin does "apachectl + * graceful"). This signal will be blocked in all threads of a child + * process except for the listener thread. + */ +#define LISTENER_SIGNAL SIGHUP + +/* The WORKER_SIGNAL signal will be sent from the main thread to the + * worker threads during an ungraceful restart or shutdown. + * This ensures that on systems (i.e., Linux) where closing the worker + * socket doesn't awake the worker thread when it is polling on the socket + * (especially in apr_wait_for_io_or_timeout() when handling + * Keep-Alive connections), close_worker_sockets() and join_workers() + * still function in timely manner and allow ungraceful shutdowns to + * proceed to completion. Otherwise join_workers() doesn't return + * before the main process decides the child process is non-responsive + * and sends a SIGKILL. + */ +#define WORKER_SIGNAL AP_SIG_GRACEFUL + +/* An array of socket descriptors in use by each thread used to + * perform a non-graceful (forced) shutdown of the server. */ +static apr_socket_t **worker_sockets; + +static void close_worker_sockets(void) +{ + int i; + for (i = 0; i < threads_per_child; i++) { + if (worker_sockets[i]) { + apr_socket_close(worker_sockets[i]); + worker_sockets[i] = NULL; + } + } +} + +static void wakeup_listener(void) +{ + listener_may_exit = 1; + if (!listener_os_thread) { + /* XXX there is an obscure path that this doesn't handle perfectly: + * right after listener thread is created but before + * listener_os_thread is set, the first worker thread hits an + * error and starts graceful termination + */ + return; + } + + /* unblock the listener if it's waiting for a worker */ + ap_queue_info_term(worker_queue_info); + + /* + * we should just be able to "kill(ap_my_pid, LISTENER_SIGNAL)" on all + * platforms and wake up the listener thread since it is the only thread + * with SIGHUP unblocked, but that doesn't work on Linux + */ +#ifdef HAVE_PTHREAD_KILL + pthread_kill(*listener_os_thread, LISTENER_SIGNAL); +#else + kill(ap_my_pid, LISTENER_SIGNAL); +#endif +} + +#define ST_INIT 0 +#define ST_GRACEFUL 1 +#define ST_UNGRACEFUL 2 + +static int terminate_mode = ST_INIT; + +static void signal_threads(int mode) +{ + if (terminate_mode == mode) { + return; + } + terminate_mode = mode; + retained->mpm->mpm_state = AP_MPMQ_STOPPING; + + /* in case we weren't called from the listener thread, wake up the + * listener thread + */ + wakeup_listener(); + + /* for ungraceful termination, let the workers exit now; + * for graceful termination, the listener thread will notify the + * workers to exit once it has stopped accepting new connections + */ + if (mode == ST_UNGRACEFUL) { + workers_may_exit = 1; + ap_queue_interrupt_all(worker_queue); + close_worker_sockets(); /* forcefully kill all current connections */ + } + + ap_run_child_stopping(pchild, mode == ST_GRACEFUL); +} + +static int worker_query(int query_code, int *result, apr_status_t *rv) +{ + *rv = APR_SUCCESS; + switch (query_code) { + case AP_MPMQ_MAX_DAEMON_USED: + *result = retained->max_daemons_limit; + break; + case AP_MPMQ_IS_THREADED: + *result = AP_MPMQ_STATIC; + 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 = thread_limit; + break; + case AP_MPMQ_MAX_THREADS: + *result = threads_per_child; + break; + case AP_MPMQ_MIN_SPARE_DAEMONS: + *result = 0; + break; + case AP_MPMQ_MIN_SPARE_THREADS: + *result = min_spare_threads; + break; + case AP_MPMQ_MAX_SPARE_DAEMONS: + *result = 0; + break; + case AP_MPMQ_MAX_SPARE_THREADS: + *result = max_spare_threads; + 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 void worker_note_child_killed(int childnum, pid_t pid, ap_generation_t gen) +{ + if (childnum != -1) { /* child had a scoreboard slot? */ + 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; + } + else { + ap_run_child_status(ap_server_conf, pid, gen, -1, MPM_CHILD_EXITED); + } +} + +static void worker_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); +} + +static void worker_note_child_lost_slot(int slot, pid_t newpid) +{ + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(00263) + "pid %" APR_PID_T_FMT " taking over scoreboard slot from " + "%" APR_PID_T_FMT "%s", + newpid, + ap_scoreboard_image->parent[slot].pid, + ap_scoreboard_image->parent[slot].quiescing ? + " (quiescing)" : ""); + ap_run_child_status(ap_server_conf, + ap_scoreboard_image->parent[slot].pid, + ap_scoreboard_image->parent[slot].generation, + slot, MPM_CHILD_LOST_SLOT); + /* Don't forget about this exiting child process, or we + * won't be able to kill it if it doesn't exit by the + * time the server is shut down. + */ + ap_register_extra_mpm_process(ap_scoreboard_image->parent[slot].pid, + ap_scoreboard_image->parent[slot].generation); +} + +static const char *worker_get_name(void) +{ + return "worker"; +} + +/* 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; + if (terminate_mode == ST_INIT) { + ap_run_child_stopping(pchild, 0); + } + + if (pchild) { + apr_pool_destroy(pchild); + } + + if (one_process) { + worker_note_child_killed(/* slot */ 0, 0, 0); + } + + exit(code); +} + +static void just_die(int sig) +{ + clean_child_exit(0); +} + +/***************************************************************** + * Connection structures and accounting... + */ + +static int child_fatal; + +/***************************************************************** + * Here follows a long bunch of generic server bookkeeping stuff... + */ + +/***************************************************************** + * Child process main loop. + */ + +static void process_socket(apr_thread_t *thd, apr_pool_t *p, apr_socket_t *sock, + int my_child_num, + int my_thread_num, apr_bucket_alloc_t *bucket_alloc) +{ + conn_rec *current_conn; + long conn_id = ID_FROM_CHILD_THREAD(my_child_num, my_thread_num); + ap_sb_handle_t *sbh; + + ap_create_sb_handle(&sbh, p, my_child_num, my_thread_num); + + current_conn = ap_run_create_connection(p, ap_server_conf, sock, + conn_id, sbh, bucket_alloc); + if (current_conn) { + current_conn->current_thread = thd; + ap_process_connection(current_conn, sock); + ap_lingering_close(current_conn); + } +} + +/* requests_this_child has gone to zero or below. See if the admin coded + "MaxConnectionsPerChild 0", and keep going in that case. Doing it this way + simplifies the hot path in worker_thread */ +static void check_infinite_requests(void) +{ + if (ap_max_requests_per_child) { + signal_threads(ST_GRACEFUL); + } + else { + requests_this_child = INT_MAX; /* keep going */ + } +} + +static void unblock_signal(int sig) +{ + sigset_t sig_mask; + + sigemptyset(&sig_mask); + sigaddset(&sig_mask, sig); +#if defined(SIGPROCMASK_SETS_THREAD_MASK) + sigprocmask(SIG_UNBLOCK, &sig_mask, NULL); +#else + pthread_sigmask(SIG_UNBLOCK, &sig_mask, NULL); +#endif +} + +static void dummy_signal_handler(int sig) +{ + /* XXX If specifying SIG_IGN is guaranteed to unblock a syscall, + * then we don't need this goofy function. + */ +} + +static void accept_mutex_error(const char *func, apr_status_t rv, int process_slot) +{ + int level = APLOG_EMERG; + + if (ap_scoreboard_image->parent[process_slot].generation != + ap_scoreboard_image->global->running_generation) { + level = APLOG_DEBUG; /* common to get these at restart time */ + } + else if (requests_this_child == INT_MAX + || ((requests_this_child == ap_max_requests_per_child) + && ap_max_requests_per_child)) { + ap_log_error(APLOG_MARK, level, rv, ap_server_conf, APLOGNO(00272) + "apr_proc_mutex_%s failed " + "before this child process served any requests.", + func); + clean_child_exit(APEXIT_CHILDSICK); + } + ap_log_error(APLOG_MARK, level, rv, ap_server_conf, APLOGNO(00273) + "apr_proc_mutex_%s failed. Attempting to " + "shutdown process gracefully.", func); + signal_threads(ST_GRACEFUL); +} + +static void * APR_THREAD_FUNC listener_thread(apr_thread_t *thd, void * dummy) +{ + proc_info * ti = dummy; + int process_slot = ti->pid; + void *csd = NULL; + apr_pool_t *ptrans = NULL; /* Pool for per-transaction stuff */ + apr_status_t rv; + ap_listen_rec *lr = NULL; + int have_idle_worker = 0; + int last_poll_idx = 0; + + free(ti); + + /* Unblock the signal used to wake this thread up, and set a handler for + * it. + */ + apr_signal(LISTENER_SIGNAL, dummy_signal_handler); + unblock_signal(LISTENER_SIGNAL); + + /* TODO: Switch to a system where threads reuse the results from earlier + poll calls - manoj */ + while (1) { + /* TODO: requests_this_child should be synchronized - aaron */ + if (requests_this_child <= 0) { + check_infinite_requests(); + } + if (listener_may_exit) break; + + if (!have_idle_worker) { + rv = ap_queue_info_wait_for_idler(worker_queue_info, NULL); + if (APR_STATUS_IS_EOF(rv)) { + break; /* we've been signaled to die now */ + } + else if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, + "apr_queue_info_wait failed. Attempting to " + " shutdown process gracefully."); + signal_threads(ST_GRACEFUL); + break; + } + have_idle_worker = 1; + } + + /* We've already decremented the idle worker count inside + * ap_queue_info_wait_for_idler. */ + + if ((rv = SAFE_ACCEPT(apr_proc_mutex_lock(my_bucket->mutex))) + != APR_SUCCESS) { + + if (!listener_may_exit) { + accept_mutex_error("lock", rv, process_slot); + } + break; /* skip the lock release */ + } + + if (!my_bucket->listeners->next) { + /* Only one listener, so skip the poll */ + lr = my_bucket->listeners; + } + else { + while (!listener_may_exit) { + apr_int32_t numdesc; + const apr_pollfd_t *pdesc; + + rv = apr_pollset_poll(worker_pollset, -1, &numdesc, &pdesc); + if (rv != APR_SUCCESS) { + if (APR_STATUS_IS_EINTR(rv)) { + continue; + } + + /* apr_pollset_poll() will only return errors in catastrophic + * circumstances. Let's try exiting gracefully, for now. */ + ap_log_error(APLOG_MARK, APLOG_ERR, rv, ap_server_conf, APLOGNO(03137) + "apr_pollset_poll: (listen)"); + signal_threads(ST_GRACEFUL); + } + + if (listener_may_exit) break; + + /* 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; + break; + + } /* while */ + + } /* if/else */ + + if (!listener_may_exit) { + /* the following pops a recycled ptrans pool off a stack */ + ap_queue_info_pop_pool(worker_queue_info, &ptrans); + if (ptrans == NULL) { + /* we can't use a recycled transaction pool this time. + * create a new transaction pool */ + apr_allocator_t *allocator; + + apr_allocator_create(&allocator); + apr_allocator_max_free_set(allocator, ap_max_mem_free); + apr_pool_create_ex(&ptrans, pconf, NULL, allocator); + apr_allocator_owner_set(allocator, ptrans); + apr_pool_tag(ptrans, "transaction"); + } + rv = lr->accept_func(&csd, lr, ptrans); + /* later we trash rv and rely on csd to indicate success/failure */ + AP_DEBUG_ASSERT(rv == APR_SUCCESS || !csd); + + if (rv == APR_EGENERAL) { + /* E[NM]FILE, ENOMEM, etc */ + resource_shortage = 1; + signal_threads(ST_GRACEFUL); + } + if ((rv = SAFE_ACCEPT(apr_proc_mutex_unlock(my_bucket->mutex))) + != APR_SUCCESS) { + + if (listener_may_exit) { + break; + } + accept_mutex_error("unlock", rv, process_slot); + } + if (csd != NULL) { + rv = ap_queue_push_socket(worker_queue, csd, NULL, ptrans); + if (rv) { + /* trash the connection; we couldn't queue the connected + * socket to a worker + */ + apr_socket_close(csd); + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf, APLOGNO(03138) + "ap_queue_push_socket failed"); + } + else { + have_idle_worker = 0; + } + } + } + else { + if ((rv = SAFE_ACCEPT(apr_proc_mutex_unlock(my_bucket->mutex))) + != APR_SUCCESS) { + int level = APLOG_EMERG; + + if (ap_scoreboard_image->parent[process_slot].generation != + ap_scoreboard_image->global->running_generation) { + level = APLOG_DEBUG; /* common to get these at restart time */ + } + ap_log_error(APLOG_MARK, level, rv, ap_server_conf, APLOGNO(00274) + "apr_proc_mutex_unlock failed. Attempting to " + "shutdown process gracefully."); + signal_threads(ST_GRACEFUL); + } + break; + } + } + + ap_close_listeners_ex(my_bucket->listeners); + ap_queue_info_free_idle_pools(worker_queue_info); + ap_queue_term(worker_queue); + dying = 1; + ap_scoreboard_image->parent[process_slot].quiescing = 1; + + /* wake up the main thread */ + kill(ap_my_pid, SIGTERM); + + apr_thread_exit(thd, APR_SUCCESS); + return NULL; +} + +/* XXX For ungraceful termination/restart, we definitely don't want to + * wait for active connections to finish but we may want to wait + * for idle workers to get out of the queue code and release mutexes, + * since those mutexes are cleaned up pretty soon and some systems + * may not react favorably (i.e., segfault) if operations are attempted + * on cleaned-up mutexes. + */ +static void * APR_THREAD_FUNC worker_thread(apr_thread_t *thd, void * dummy) +{ + proc_info * ti = dummy; + int process_slot = ti->pid; + int thread_slot = ti->tid; + apr_socket_t *csd = NULL; + apr_bucket_alloc_t *bucket_alloc; + apr_pool_t *last_ptrans = NULL; + apr_pool_t *ptrans; /* Pool for per-transaction stuff */ + apr_status_t rv; + int is_idle = 0; + + free(ti); + + ap_scoreboard_image->servers[process_slot][thread_slot].pid = ap_my_pid; + ap_scoreboard_image->servers[process_slot][thread_slot].tid = apr_os_thread_current(); + ap_scoreboard_image->servers[process_slot][thread_slot].generation = retained->mpm->my_generation; + ap_update_child_status_from_indexes(process_slot, thread_slot, + SERVER_STARTING, NULL); + +#ifdef HAVE_PTHREAD_KILL + apr_signal(WORKER_SIGNAL, dummy_signal_handler); + unblock_signal(WORKER_SIGNAL); +#endif + + while (!workers_may_exit) { + if (!is_idle) { + rv = ap_queue_info_set_idle(worker_queue_info, last_ptrans); + last_ptrans = NULL; + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, + "ap_queue_info_set_idle failed. Attempting to " + "shutdown process gracefully."); + signal_threads(ST_GRACEFUL); + break; + } + is_idle = 1; + } + + ap_update_child_status_from_indexes(process_slot, thread_slot, + SERVER_READY, NULL); +worker_pop: + if (workers_may_exit) { + break; + } + rv = ap_queue_pop_socket(worker_queue, &csd, &ptrans); + + if (rv != APR_SUCCESS) { + /* We get APR_EOF during a graceful shutdown once all the connections + * accepted by this server process have been handled. + */ + if (APR_STATUS_IS_EOF(rv)) { + break; + } + /* We get APR_EINTR whenever ap_queue_pop_*() has been interrupted + * from an explicit call to ap_queue_interrupt_all(). This allows + * us to unblock threads stuck in ap_queue_pop_*() when a shutdown + * is pending. + * + * If workers_may_exit is set and this is ungraceful termination/ + * restart, we are bound to get an error on some systems (e.g., + * AIX, which sanity-checks mutex operations) since the queue + * may have already been cleaned up. Don't log the "error" if + * workers_may_exit is set. + */ + else if (APR_STATUS_IS_EINTR(rv)) { + goto worker_pop; + } + /* We got some other error. */ + else if (!workers_may_exit) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf, APLOGNO(03139) + "ap_queue_pop_socket failed"); + } + continue; + } + is_idle = 0; + worker_sockets[thread_slot] = csd; + bucket_alloc = apr_bucket_alloc_create(ptrans); + process_socket(thd, ptrans, csd, process_slot, thread_slot, bucket_alloc); + worker_sockets[thread_slot] = NULL; + requests_this_child--; + apr_pool_clear(ptrans); + last_ptrans = ptrans; + } + + ap_update_child_status_from_indexes(process_slot, thread_slot, + dying ? SERVER_DEAD + : SERVER_GRACEFUL, NULL); + + apr_thread_exit(thd, APR_SUCCESS); + return NULL; +} + +static int check_signal(int signum) +{ + switch (signum) { + case SIGTERM: + case SIGINT: + return 1; + } + return 0; +} + +static void create_listener_thread(thread_starter *ts) +{ + int my_child_num = ts->child_num_arg; + apr_threadattr_t *thread_attr = ts->threadattr; + proc_info *my_info; + apr_status_t rv; + + my_info = (proc_info *)ap_malloc(sizeof(proc_info)); + my_info->pid = my_child_num; + my_info->tid = -1; /* listener thread doesn't have a thread slot */ + my_info->sd = 0; + rv = ap_thread_create(&ts->listener, thread_attr, listener_thread, + my_info, pruntime); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf, APLOGNO(00275) + "ap_thread_create: unable to create listener thread"); + /* let the parent decide how bad this really is */ + clean_child_exit(APEXIT_CHILDSICK); + } + apr_os_thread_get(&listener_os_thread, ts->listener); +} + +static void setup_threads_runtime(void) +{ + ap_listen_rec *lr; + apr_status_t rv; + + /* All threads (listener, workers) and synchronization objects (queues, + * pollset, mutexes...) created here should have at least the lifetime of + * the connections they handle (i.e. ptrans). We can't use this thread's + * self pool because all these objects survive it, nor use pchild or pconf + * directly because this starter thread races with other modules' runtime, + * nor finally pchild (or subpool thereof) because it is killed explicitly + * before pconf (thus connections/ptrans can live longer, which matters in + * ONE_PROCESS mode). So this leaves us with a subpool of pconf, created + * before any ptrans hence destroyed after. + */ + apr_pool_create(&pruntime, pconf); + apr_pool_tag(pruntime, "mpm_runtime"); + + /* We must create the fd queues before we start up the listener + * and worker threads. */ + rv = ap_queue_create(&worker_queue, threads_per_child, pruntime); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf, APLOGNO(03140) + "ap_queue_create() failed"); + clean_child_exit(APEXIT_CHILDFATAL); + } + + rv = ap_queue_info_create(&worker_queue_info, pruntime, + threads_per_child, -1); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf, APLOGNO(03141) + "ap_queue_info_create() failed"); + clean_child_exit(APEXIT_CHILDFATAL); + } + + /* Create the main pollset */ + rv = apr_pollset_create(&worker_pollset, num_listensocks, pruntime, + APR_POLLSET_NOCOPY); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(03285) + "Couldn't create pollset in thread;" + " check system or user limits"); + /* let the parent decide how bad this really is */ + clean_child_exit(APEXIT_CHILDSICK); + } + + for (lr = my_bucket->listeners; lr != NULL; lr = lr->next) { + apr_pollfd_t *pfd = apr_pcalloc(pruntime, sizeof *pfd); + + pfd->desc_type = APR_POLL_SOCKET; + pfd->desc.s = lr->sd; + pfd->reqevents = APR_POLLIN; + pfd->client_data = lr; + + rv = apr_pollset_add(worker_pollset, pfd); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(03286) + "Couldn't create add listener to pollset;" + " check system or user limits"); + /* let the parent decide how bad this really is */ + clean_child_exit(APEXIT_CHILDSICK); + } + + lr->accept_func = ap_unixd_accept; + } + + worker_sockets = apr_pcalloc(pruntime, threads_per_child * + sizeof(apr_socket_t *)); +} + +/* XXX under some circumstances not understood, children can get stuck + * in start_threads forever trying to take over slots which will + * never be cleaned up; for now there is an APLOG_DEBUG message issued + * every so often when this condition occurs + */ +static void * APR_THREAD_FUNC start_threads(apr_thread_t *thd, void *dummy) +{ + thread_starter *ts = dummy; + apr_thread_t **threads = ts->threads; + apr_threadattr_t *thread_attr = ts->threadattr; + int my_child_num = ts->child_num_arg; + proc_info *my_info; + apr_status_t rv; + int threads_created = 0; + int listener_started = 0; + int prev_threads_created; + int loops, i; + + loops = prev_threads_created = 0; + while (1) { + /* threads_per_child does not include the listener thread */ + for (i = 0; i < threads_per_child; i++) { + int status = ap_scoreboard_image->servers[my_child_num][i].status; + + if (status != SERVER_GRACEFUL && status != SERVER_DEAD) { + continue; + } + + my_info = (proc_info *)ap_malloc(sizeof(proc_info)); + my_info->pid = my_child_num; + my_info->tid = i; + my_info->sd = 0; + + /* We are creating threads right now */ + ap_update_child_status_from_indexes(my_child_num, i, + SERVER_STARTING, NULL); + /* We let each thread update its own scoreboard entry. This is + * done because it lets us deal with tid better. + */ + rv = ap_thread_create(&threads[i], thread_attr, + worker_thread, my_info, pruntime); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf, APLOGNO(03142) + "ap_thread_create: unable to create worker thread"); + /* let the parent decide how bad this really is */ + clean_child_exit(APEXIT_CHILDSICK); + } + threads_created++; + } + /* Start the listener only when there are workers available */ + if (!listener_started && threads_created) { + create_listener_thread(ts); + listener_started = 1; + } + if (start_thread_may_exit || threads_created == threads_per_child) { + break; + } + /* wait for previous generation to clean up an entry */ + apr_sleep(apr_time_from_sec(1)); + ++loops; + if (loops % 120 == 0) { /* every couple of minutes */ + if (prev_threads_created == threads_created) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, + "child %" APR_PID_T_FMT " isn't taking over " + "slots very quickly (%d of %d)", + ap_my_pid, threads_created, threads_per_child); + } + prev_threads_created = threads_created; + } + } + + /* What state should this child_main process be listed as in the + * scoreboard...? + * ap_update_child_status_from_indexes(my_child_num, i, SERVER_STARTING, + * (request_rec *) NULL); + * + * This state should be listed separately in the scoreboard, in some kind + * of process_status, not mixed in with the worker threads' status. + * "life_status" is almost right, but it's in the worker's structure, and + * the name could be clearer. gla + */ + apr_thread_exit(thd, APR_SUCCESS); + return NULL; +} + +static void join_workers(apr_thread_t *listener, apr_thread_t **threads, + int mode) +{ + int i; + apr_status_t rv, thread_rv; + + if (listener) { + int iter; + + /* deal with a rare timing window which affects waking up the + * listener thread... if the signal sent to the listener thread + * is delivered between the time it verifies that the + * listener_may_exit flag is clear and the time it enters a + * blocking syscall, the signal didn't do any good... work around + * that by sleeping briefly and sending it again + */ + + iter = 0; + while (iter < 10 && +#ifdef HAVE_PTHREAD_KILL + pthread_kill(*listener_os_thread, 0) +#else + kill(ap_my_pid, 0) +#endif + == 0) { + /* listener not dead yet */ + apr_sleep(apr_time_make(0, 500000)); + wakeup_listener(); + ++iter; + } + if (iter >= 10) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(00276) + "the listener thread didn't exit"); + } + else { + rv = apr_thread_join(&thread_rv, listener); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf, APLOGNO(00277) + "apr_thread_join: unable to join listener thread"); + } + } + } + + for (i = 0; i < threads_per_child; i++) { + if (threads[i]) { /* if we ever created this thread */ + if (mode != ST_GRACEFUL) { +#ifdef HAVE_PTHREAD_KILL + apr_os_thread_t *worker_os_thread; + + apr_os_thread_get(&worker_os_thread, threads[i]); + pthread_kill(*worker_os_thread, WORKER_SIGNAL); +#endif + } + + rv = apr_thread_join(&thread_rv, threads[i]); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf, APLOGNO(00278) + "apr_thread_join: unable to join worker " + "thread %d", + i); + } + } + } +} + +static void join_start_thread(apr_thread_t *start_thread_id) +{ + apr_status_t rv, thread_rv; + + start_thread_may_exit = 1; /* tell it to give up in case it is still + * trying to take over slots from a + * previous generation + */ + rv = apr_thread_join(&thread_rv, start_thread_id); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf, APLOGNO(00279) + "apr_thread_join: unable to join the start " + "thread"); + } +} + +static void child_main(int child_num_arg, int child_bucket) +{ + apr_thread_t **threads; + apr_status_t rv; + thread_starter *ts; + apr_threadattr_t *thread_attr; + apr_thread_t *start_thread_id; + int i; + + /* for benefit of any hooks that run as this child initializes */ + retained->mpm->mpm_state = AP_MPMQ_STARTING; + + ap_my_pid = getpid(); + 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_pool_create(&pchild, pconf); + apr_pool_tag(pchild, "pchild"); + +#if AP_HAS_THREAD_LOCAL + if (!one_process) { + apr_thread_t *thd = NULL; + if ((rv = ap_thread_main_create(&thd, pchild))) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(10375) + "Couldn't initialize child main thread"); + clean_child_exit(APEXIT_CHILDFATAL); + } + } +#endif + + /* 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_podx_close(all_buckets[i].pod); + } + } + + /*stuff to do before we switch id's, so we have permissions.*/ + ap_reopen_scoreboard(pchild, NULL, 0); + + rv = SAFE_ACCEPT(apr_proc_mutex_child_init(&my_bucket->mutex, + apr_proc_mutex_lockfile(my_bucket->mutex), + pchild)); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(00280) + "Couldn't initialize cross-process lock in child"); + clean_child_exit(APEXIT_CHILDFATAL); + } + + /* done with init critical section */ + if (ap_run_drop_privileges(pchild, ap_server_conf)) { + clean_child_exit(APEXIT_CHILDFATAL); + } + + /* Just use the standard apr_setup_signal_thread to block all signals + * from being received. The child processes no longer use signals for + * any communication with the parent process. Let's also do this before + * child_init() hooks are called and possibly create threads that + * otherwise could "steal" (implicitly) MPM's signals. + */ + rv = apr_setup_signal_thread(); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(00281) + "Couldn't initialize signal thread"); + clean_child_exit(APEXIT_CHILDFATAL); + } + + ap_run_child_init(pchild, ap_server_conf); + + if (ap_max_requests_per_child) { + requests_this_child = ap_max_requests_per_child; + } + else { + /* coding a value of zero means infinity */ + requests_this_child = INT_MAX; + } + + /* Setup threads */ + + /* Globals used by signal_threads() so to be initialized before */ + setup_threads_runtime(); + + /* clear the storage; we may not create all our threads immediately, + * and we want a 0 entry to indicate a thread which was not created + */ + threads = (apr_thread_t **)ap_calloc(1, + sizeof(apr_thread_t *) * threads_per_child); + ts = (thread_starter *)apr_palloc(pchild, sizeof(*ts)); + + apr_threadattr_create(&thread_attr, pchild); + /* 0 means PTHREAD_CREATE_JOINABLE */ + apr_threadattr_detach_set(thread_attr, 0); + + if (ap_thread_stacksize != 0) { + rv = apr_threadattr_stacksize_set(thread_attr, ap_thread_stacksize); + if (rv != APR_SUCCESS && rv != APR_ENOTIMPL) { + ap_log_error(APLOG_MARK, APLOG_WARNING, rv, ap_server_conf, APLOGNO(02435) + "WARNING: ThreadStackSize of %" APR_SIZE_T_FMT " is " + "inappropriate, using default", + ap_thread_stacksize); + } + } + + ts->threads = threads; + ts->listener = NULL; + ts->child_num_arg = child_num_arg; + ts->threadattr = thread_attr; + + rv = ap_thread_create(&start_thread_id, thread_attr, start_threads, + ts, pchild); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf, APLOGNO(00282) + "ap_thread_create: unable to create worker thread"); + /* let the parent decide how bad this really is */ + clean_child_exit(APEXIT_CHILDSICK); + } + + retained->mpm->mpm_state = AP_MPMQ_RUNNING; + + /* If we are only running in one_process mode, we will want to + * still handle signals. */ + if (one_process) { + /* Block until we get a terminating signal. */ + apr_signal_thread(check_signal); + /* make sure the start thread has finished; signal_threads() + * and join_workers() depend on that + */ + /* XXX join_start_thread() won't be awakened if one of our + * threads encounters a critical error and attempts to + * shutdown this child + */ + join_start_thread(start_thread_id); + signal_threads(ST_UNGRACEFUL); /* helps us terminate a little more + * quickly than the dispatch of the signal thread + * beats the Pipe of Death and the browsers + */ + /* A terminating signal was received. Now join each of the + * workers to clean them up. + * If the worker already exited, then the join frees + * their resources and returns. + * If the worker hasn't exited, then this blocks until + * they have (then cleans up). + */ + join_workers(ts->listener, threads, ST_UNGRACEFUL); + } + else { /* !one_process */ + /* remove SIGTERM from the set of blocked signals... if one of + * the other threads in the process needs to take us down + * (e.g., for MaxConnectionsPerChild) it will send us SIGTERM + */ + apr_signal(SIGTERM, dummy_signal_handler); + unblock_signal(SIGTERM); + /* Watch for any messages from the parent over the POD */ + while (1) { + rv = ap_mpm_podx_check(my_bucket->pod); + if (rv == AP_MPM_PODX_NORESTART) { + /* see if termination was triggered while we slept */ + switch(terminate_mode) { + case ST_GRACEFUL: + rv = AP_MPM_PODX_GRACEFUL; + break; + case ST_UNGRACEFUL: + rv = AP_MPM_PODX_RESTART; + break; + } + } + if (rv == AP_MPM_PODX_GRACEFUL || rv == AP_MPM_PODX_RESTART) { + /* make sure the start thread has finished; + * signal_threads() and join_workers depend on that + */ + join_start_thread(start_thread_id); + signal_threads(rv == AP_MPM_PODX_GRACEFUL ? ST_GRACEFUL : ST_UNGRACEFUL); + break; + } + } + + /* A terminating signal was received. Now join each of the + * workers to clean them up. + * If the worker already exited, then the join frees + * their resources and returns. + * If the worker hasn't exited, then this blocks until + * they have (then cleans up). + */ + join_workers(ts->listener, threads, + rv == AP_MPM_PODX_GRACEFUL ? ST_GRACEFUL : ST_UNGRACEFUL); + } + + free(threads); + + clean_child_exit(resource_shortage ? APEXIT_CHILDSICK : 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]; + + worker_note_child_started(slot, getpid()); + child_main(slot, 0); + /* NOTREACHED */ + ap_assert(0); + return -1; + } + + if ((pid = fork()) == -1) { + ap_log_error(APLOG_MARK, APLOG_ERR, errno, s, APLOGNO(00283) + "fork: Unable to fork new process"); + /* fork didn't succeed. There's no need to touch the scoreboard; + * if we were trying to replace a failed child process, then + * server_main_loop() marked its workers SERVER_DEAD, and if + * we were trying to replace a child process that exited normally, + * its worker_thread()s left SERVER_DEAD or SERVER_GRACEFUL behind. + */ + + /* 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. */ + apr_sleep(apr_time_from_sec(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(00284) + "processor unbind failed"); +#endif + RAISE_SIGSTOP(MAKE_CHILD); + + apr_signal(SIGTERM, just_die); + child_main(slot, bucket); + /* NOTREACHED */ + ap_assert(0); + return -1; + } + + if (ap_scoreboard_image->parent[slot].pid != 0) { + /* This new child process is squatting on the scoreboard + * entry owned by an exiting child process, which cannot + * exit until all active requests complete. + */ + worker_note_child_lost_slot(slot, pid); + } + ap_scoreboard_image->parent[slot].quiescing = 0; + worker_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->parent[i].pid != 0) { + continue; + } + if (make_child(ap_server_conf, i, i % retained->mpm->num_buckets) < 0) { + break; + } + --number_to_start; + } +} + +static void perform_idle_server_maintenance(int child_bucket) +{ + int num_buckets = retained->mpm->num_buckets; + int idle_thread_count; + process_score *ps; + int free_length; + int totally_free_length = 0; + int free_slots[MAX_SPAWN_RATE]; + int last_non_dead; + int total_non_dead; + int active_thread_count = 0; + int i, j; + + /* initialize the free_list */ + free_length = 0; + + idle_thread_count = 0; + last_non_dead = -1; + total_non_dead = 0; + + for (i = 0; i < ap_daemons_limit; ++i) { + /* Initialization to satisfy the compiler. It doesn't know + * that threads_per_child is always > 0 */ + int any_dying_threads = 0; + int any_dead_threads = 0; + int all_dead_threads = 1; + int child_threads_active = 0; + + if (num_buckets > 1 && (i % num_buckets) != child_bucket) { + /* We only care about child_bucket in this call */ + continue; + } + if (i >= retained->max_daemons_limit && + totally_free_length == retained->idle_spawn_rate[child_bucket]) { + /* short cut if all active processes have been examined and + * enough empty scoreboard slots have been found + */ + break; + } + ps = &ap_scoreboard_image->parent[i]; + for (j = 0; j < threads_per_child; j++) { + int status = ap_scoreboard_image->servers[i][j].status; + + /* XXX any_dying_threads is probably no longer needed GLA */ + any_dying_threads = any_dying_threads || + (status == SERVER_GRACEFUL); + any_dead_threads = any_dead_threads || (status == SERVER_DEAD); + all_dead_threads = all_dead_threads && + (status == SERVER_DEAD || + status == SERVER_GRACEFUL); + + /* 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 (ps->pid != 0) { /* XXX just set all_dead_threads in outer for + loop if no pid? not much else matters */ + if (status <= SERVER_READY && + !ps->quiescing && + ps->generation == retained->mpm->my_generation) { + ++idle_thread_count; + } + if (status >= SERVER_READY && status < SERVER_GRACEFUL) { + ++child_threads_active; + } + } + } + active_thread_count += child_threads_active; + if (any_dead_threads + && totally_free_length < retained->idle_spawn_rate[child_bucket] + && free_length < MAX_SPAWN_RATE / num_buckets + && (!ps->pid /* no process in the slot */ + || ps->quiescing)) { /* or at least one is going away */ + if (all_dead_threads) { + /* great! we prefer these, because the new process can + * start more threads sooner. So prioritize this slot + * by putting it ahead of any slots with active threads. + * + * first, make room by moving a slot that's potentially still + * in use to the end of the array + */ + free_slots[free_length] = free_slots[totally_free_length]; + free_slots[totally_free_length++] = i; + } + else { + /* slot is still in use - back of the bus + */ + free_slots[free_length] = i; + } + ++free_length; + } + else if (child_threads_active == threads_per_child) { + had_healthy_child = 1; + } + /* XXX if (!ps->quiescing) is probably more reliable GLA */ + if (!any_dying_threads) { + ++total_non_dead; + } + if (ps->pid != 0) { + last_non_dead = i; + } + } + + retained->max_daemons_limit = last_non_dead + 1; + + if (retained->sick_child_detected) { + if (had_healthy_child) { + /* Assume this is a transient error, even though it may not be. Leave + * the server up in case it is able to serve some requests or the + * problem will be resolved. + */ + retained->sick_child_detected = 0; + } + else if (child_bucket < num_buckets - 1) { + /* check for had_healthy_child up to the last child bucket */ + return; + } + else { + /* looks like a basket case, as no child ever fully initialized; give up. + */ + retained->mpm->shutdown_pending = 1; + child_fatal = 1; + ap_log_error(APLOG_MARK, APLOG_ALERT, 0, + ap_server_conf, APLOGNO(02325) + "A resource shortage or other unrecoverable failure " + "was encountered before any child process initialized " + "successfully... httpd is exiting!"); + /* the child already logged the failure details */ + return; + } + } + + if (idle_thread_count > max_spare_threads / num_buckets) { + /* Kill off one child */ + ap_mpm_podx_signal(all_buckets[child_bucket].pod, + AP_MPM_PODX_GRACEFUL); + retained->idle_spawn_rate[child_bucket] = 1; + } + else if (idle_thread_count < min_spare_threads / num_buckets) { + /* terminate the free list */ + if (free_length == 0) { /* scoreboard is full, can't fork */ + + if (active_thread_count >= max_workers / num_buckets) { + /* no threads are "inactive" - starting, stopping, etc. */ + /* have we reached MaxRequestWorkers, or just getting close? */ + if (0 == idle_thread_count) { + if (!retained->maxclients_reported) { + /* only report this condition once */ + ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, APLOGNO(00286) + "server reached MaxRequestWorkers " + "setting, consider raising the " + "MaxRequestWorkers setting"); + retained->maxclients_reported = 1; + } + } else { + if (!retained->near_maxclients_reported) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, APLOGNO(00287) + "server is within MinSpareThreads of " + "MaxRequestWorkers, consider raising the " + "MaxRequestWorkers setting"); + retained->near_maxclients_reported = 1; + } + } + } + else { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, + ap_server_conf, APLOGNO(00288) + "scoreboard is full, not at MaxRequestWorkers"); + } + retained->idle_spawn_rate[child_bucket] = 1; + } + else { + if (free_length > retained->idle_spawn_rate[child_bucket]) { + free_length = retained->idle_spawn_rate[child_bucket]; + } + if (retained->idle_spawn_rate[child_bucket] >= 8) { + ap_log_error(APLOG_MARK, APLOG_INFO, 0, + ap_server_conf, APLOGNO(00289) + "server seems busy, (you may need " + "to increase StartServers, ThreadsPerChild " + "or Min/MaxSpareThreads), " + "spawning %d children, there are around %d idle " + "threads, and %d total children", free_length, + idle_thread_count, total_non_dead); + } + for (i = 0; i < free_length; ++i) { + make_child(ap_server_conf, free_slots[i], child_bucket); + } + /* 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[child_bucket] + < MAX_SPAWN_RATE / num_buckets) { + retained->idle_spawn_rate[child_bucket] *= 2; + } + } + } + else { + retained->idle_spawn_rate[child_bucket] = 1; + } +} + +static void server_main_loop(int remaining_children_to_start) +{ + int num_buckets = retained->mpm->num_buckets; + int successive_kills = 0; + ap_generation_t old_gen; + int child_slot; + apr_exit_why_e exitwhy; + int status, processed_status; + apr_proc_t pid; + int i; + + while (!retained->mpm->restart_pending && !retained->mpm->shutdown_pending) { + ap_wait_or_timeout(&exitwhy, &status, &pid, pconf, ap_server_conf); + + 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->shutdown_pending = 1; + child_fatal = 1; + return; + } + else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ap_server_conf, APLOGNO(00290) + "Ignoring fatal error in child of previous " + "generation (pid %ld).", + (long)pid.pid); + retained->sick_child_detected = 1; + } + } + else if (processed_status == APEXIT_CHILDSICK) { + /* tell perform_idle_server_maintenance to check into this + * on the next timer pop + */ + retained->sick_child_detected = 1; + } + /* non-fatal death... note that it's gone in the scoreboard. */ + if (child_slot >= 0) { + process_score *ps; + + for (i = 0; i < threads_per_child; i++) + ap_update_child_status_from_indexes(child_slot, i, + SERVER_DEAD, NULL); + + worker_note_child_killed(child_slot, 0, 0); + ps = &ap_scoreboard_image->parent[child_slot]; + ps->quiescing = 0; + if (processed_status == APEXIT_CHILDSICK) { + /* resource shortage, minimize the fork rate */ + retained->idle_spawn_rate[child_slot % num_buckets] = 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, + child_slot % num_buckets); + --remaining_children_to_start; + } + } + else if (ap_unregister_extra_mpm_process(pid.pid, &old_gen) == 1) { + worker_note_child_killed(-1, /* already out of the scoreboard */ + pid.pid, old_gen); + if (processed_status == APEXIT_CHILDSICK + && old_gen == retained->mpm->my_generation) { + /* resource shortage, minimize the fork rate */ + for (i = 0; i < num_buckets; i++) { + retained->idle_spawn_rate[i] = 1; + } + } +#if APR_HAS_OTHER_CHILD + } + else if (apr_proc_other_child_alert(&pid, APR_OC_REASON_DEATH, + status) == 0) { + /* 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(00291) + "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. If a child is + * killed by a signal (faulting) we want to restart it ASAP + * though, up to 3 successive faults or we stop this until + * a timeout happens again (to avoid the flood of fork()ed + * processes that keep being killed early). + */ + if (child_slot < 0 || !APR_PROC_CHECK_SIGNALED(exitwhy)) { + continue; + } + if (++successive_kills >= 3) { + if (successive_kills % 10 == 3) { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, + ap_server_conf, APLOGNO(10393) + "children are killed successively!"); + } + continue; + } + ++remaining_children_to_start; + } + else { + successive_kills = 0; + } + + 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; + } + + for (i = 0; i < num_buckets; i++) { + perform_idle_server_maintenance(i); + } + } +} + +static int worker_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) +{ + int num_buckets = retained->mpm->num_buckets; + 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); + + /* 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; + /* We want to create as much children at a time as the number of buckets, + * so to optimally accept connections (evenly distributed across buckets). + * Thus min_spare_threads should at least maintain num_buckets children, + * and max_spare_threads allow num_buckets more children w/o triggering + * immediately (e.g. num_buckets idle threads margin, one per bucket). + */ + if (min_spare_threads < threads_per_child * (num_buckets - 1) + num_buckets) + min_spare_threads = threads_per_child * (num_buckets - 1) + num_buckets; + if (max_spare_threads < min_spare_threads + (threads_per_child + 1) * num_buckets) + max_spare_threads = min_spare_threads + (threads_per_child + 1) * 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 may start a new one, until + * there are at least min_spare_threads idle threads, counting across + * all children. But we may be permitted to start more children 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(00292) + "%s configured -- resuming normal operations", + ap_get_server_description()); + ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf, APLOGNO(00293) + "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(00294) + "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; + + server_main_loop(remaining_children_to_start); + 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... + */ + for (i = 0; i < num_buckets; i++) { + ap_mpm_podx_killpg(all_buckets[i].pod, ap_daemons_limit, + AP_MPM_PODX_RESTART); + } + ap_reclaim_child_processes(1, /* Start with SIGTERM */ + worker_note_child_killed); + + if (!child_fatal) { + /* 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(00295) "caught SIGTERM, shutting down"); + } + return DONE; + } + + if (retained->mpm->shutdown_pending) { + /* Time to gracefully shut down: + * Kill child processes, tell them to call child_exit, etc... + */ + int active_children; + int index; + apr_time_t cutoff = 0; + + /* Close our listeners, and then ask our children to do same */ + ap_close_listeners(); + + for (i = 0; i < num_buckets; i++) { + ap_mpm_podx_killpg(all_buckets[i].pod, ap_daemons_limit, + AP_MPM_PODX_GRACEFUL); + } + ap_relieve_child_processes(worker_note_child_killed); + + if (!child_fatal) { + /* 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(00296) + "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 */ + apr_sleep(apr_time_from_sec(1)); + + /* Relieve any children which have now exited */ + ap_relieve_child_processes(worker_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. + */ + for (i = 0; i < num_buckets; i++) { + ap_mpm_podx_killpg(all_buckets[i].pod, ap_daemons_limit, + AP_MPM_PODX_RESTART); + } + ap_reclaim_child_processes(1, worker_note_child_killed); + + 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(00297) + AP_SIG_GRACEFUL_STRING " received. Doing graceful restart"); + /* wake up the children...time to die. But we'll have more soon */ + for (i = 0; i < num_buckets; i++) { + ap_mpm_podx_killpg(all_buckets[i].pod, ap_daemons_limit, + AP_MPM_PODX_GRACEFUL); + } + + /* This is mostly for debugging... so that we know what is still + * gracefully dealing with existing request. + */ + + } + else { + /* Kill 'em all. Since the child acts the same on the parents SIGTERM + * and a SIGHUP, we may as well use the same signal, because some user + * pthreads are stealing signals from us left and right. + */ + for (i = 0; i < num_buckets; i++) { + ap_mpm_podx_killpg(all_buckets[i].pod, ap_daemons_limit, + AP_MPM_PODX_RESTART); + } + + ap_reclaim_child_processes(1, /* Start with SIGTERM */ + worker_note_child_killed); + ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00298) + "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 worker_open_logs(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s) +{ + int startup = 0; + int level_flags = 0; + int num_buckets = 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) { + num_buckets = 1; + } + else if (retained->mpm->was_graceful) { + /* Preserve the number of buckets on graceful restarts. */ + num_buckets = retained->mpm->num_buckets; + } + 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 !OK; + } + + all_buckets = apr_pcalloc(pconf, num_buckets * sizeof(*all_buckets)); + for (i = 0; i < num_buckets; i++) { + if (!one_process && /* no POD in one_process mode */ + (rv = ap_mpm_podx_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]; + } + + if (retained->mpm->max_buckets < num_buckets) { + int new_max, *new_ptr; + new_max = retained->mpm->max_buckets * 2; + if (new_max < num_buckets) { + new_max = num_buckets; + } + new_ptr = (int *)apr_palloc(ap_pglobal, new_max * sizeof(int)); + if (retained->idle_spawn_rate) /* NULL at startup */ + memcpy(new_ptr, retained->idle_spawn_rate, + retained->mpm->num_buckets * sizeof(int)); + retained->idle_spawn_rate = new_ptr; + retained->mpm->max_buckets = new_max; + } + if (retained->mpm->num_buckets < num_buckets) { + int rate_max = 1; + /* If new buckets are added, set their idle spawn rate to + * the highest so far, so that they get filled as quickly + * as the existing ones. + */ + for (i = 0; i < retained->mpm->num_buckets; i++) { + if (rate_max < retained->idle_spawn_rate[i]) { + rate_max = retained->idle_spawn_rate[i]; + } + } + for (/* up to date i */; i < num_buckets; i++) { + retained->idle_spawn_rate[i] = rate_max; + } + } + retained->mpm->num_buckets = num_buckets; + + return OK; +} + +static int worker_pre_config(apr_pool_t *pconf, apr_pool_t *plog, + apr_pool_t *ptemp) +{ + int no_detach, debug, foreground; + apr_status_t rv; + const char *userdata_key = "mpm_worker_module"; + + debug = ap_exists_config_define("DEBUG"); + + if (debug) { + foreground = one_process = 1; + no_detach = 0; + } + else { + one_process = ap_exists_config_define("ONE_PROCESS"); + no_detach = ap_exists_config_define("NO_DETACH"); + foreground = ap_exists_config_define("FOREGROUND"); + } + + ap_mutex_register(pconf, 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->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, 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(00299) + "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; + min_spare_threads = DEFAULT_MIN_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD; + max_spare_threads = DEFAULT_MAX_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD; + server_limit = DEFAULT_SERVER_LIMIT; + thread_limit = DEFAULT_THREAD_LIMIT; + ap_daemons_limit = server_limit; + threads_per_child = DEFAULT_THREADS_PER_CHILD; + max_workers = ap_daemons_limit * threads_per_child; + had_healthy_child = 0; + ap_extended_status = 0; + + return OK; +} + +static int worker_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(00300) + "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(00301) + "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(00302) + "WARNING: ServerLimit of %d not allowed, " + "increasing to 1.", server_limit); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00303) + "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(00304) + "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 (thread_limit > MAX_THREAD_LIMIT) { + if (startup) { + ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00305) + "WARNING: ThreadLimit of %d exceeds compile-time " + "limit of %d threads, decreasing to %d.", + thread_limit, MAX_THREAD_LIMIT, MAX_THREAD_LIMIT); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00306) + "ThreadLimit of %d exceeds compile-time limit " + "of %d, decreasing to match", + thread_limit, MAX_THREAD_LIMIT); + } + thread_limit = MAX_THREAD_LIMIT; + } + else if (thread_limit < 1) { + if (startup) { + ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00307) + "WARNING: ThreadLimit of %d not allowed, " + "increasing to 1.", thread_limit); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00308) + "ThreadLimit of %d not allowed, increasing to 1", + thread_limit); + } + thread_limit = 1; + } + + /* you cannot change ThreadLimit across a restart; ignore + * any such attempts + */ + if (!retained->first_thread_limit) { + retained->first_thread_limit = thread_limit; + } + else if (thread_limit != retained->first_thread_limit) { + /* don't need a startup console version here */ + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00309) + "changing ThreadLimit to %d from original value of %d " + "not allowed during restart", + thread_limit, retained->first_thread_limit); + thread_limit = retained->first_thread_limit; + } + + if (threads_per_child > thread_limit) { + if (startup) { + ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00310) + "WARNING: ThreadsPerChild of %d exceeds ThreadLimit " + "of %d threads, decreasing to %d. " + "To increase, please see the ThreadLimit directive.", + threads_per_child, thread_limit, thread_limit); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00311) + "ThreadsPerChild of %d exceeds ThreadLimit " + "of %d, decreasing to match", + threads_per_child, thread_limit); + } + threads_per_child = thread_limit; + } + else if (threads_per_child < 1) { + if (startup) { + ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00312) + "WARNING: ThreadsPerChild of %d not allowed, " + "increasing to 1.", threads_per_child); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00313) + "ThreadsPerChild of %d not allowed, increasing to 1", + threads_per_child); + } + threads_per_child = 1; + } + + if (max_workers < threads_per_child) { + if (startup) { + ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00314) + "WARNING: MaxRequestWorkers of %d is less than " + "ThreadsPerChild of %d, increasing to %d. " + "MaxRequestWorkers must be at least as large " + "as the number of threads in a single server.", + max_workers, threads_per_child, threads_per_child); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00315) + "MaxRequestWorkers of %d is less than ThreadsPerChild " + "of %d, increasing to match", + max_workers, threads_per_child); + } + max_workers = threads_per_child; + } + + ap_daemons_limit = max_workers / threads_per_child; + + if (max_workers % threads_per_child) { + int tmp_max_workers = ap_daemons_limit * threads_per_child; + + if (startup) { + ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00316) + "WARNING: MaxRequestWorkers of %d is not an integer " + "multiple of ThreadsPerChild of %d, decreasing to nearest " + "multiple %d, for a maximum of %d servers.", + max_workers, threads_per_child, tmp_max_workers, + ap_daemons_limit); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00317) + "MaxRequestWorkers of %d is not an integer multiple of " + "ThreadsPerChild of %d, decreasing to nearest " + "multiple %d", max_workers, threads_per_child, + tmp_max_workers); + } + max_workers = tmp_max_workers; + } + + if (ap_daemons_limit > server_limit) { + if (startup) { + ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00318) + "WARNING: MaxRequestWorkers of %d would require %d " + "servers and would exceed ServerLimit of %d, decreasing to %d. " + "To increase, please see the ServerLimit directive.", + max_workers, ap_daemons_limit, server_limit, + server_limit * threads_per_child); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00319) + "MaxRequestWorkers of %d would require %d servers and " + "exceed ServerLimit of %d, decreasing to %d", + max_workers, ap_daemons_limit, server_limit, + server_limit * threads_per_child); + } + ap_daemons_limit = server_limit; + } + + /* ap_daemons_to_start > ap_daemons_limit checked in worker_run() */ + if (ap_daemons_to_start < 1) { + if (startup) { + ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00320) + "WARNING: StartServers of %d not allowed, " + "increasing to 1.", ap_daemons_to_start); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00321) + "StartServers of %d not allowed, increasing to 1", + ap_daemons_to_start); + } + ap_daemons_to_start = 1; + } + + if (min_spare_threads < 1) { + if (startup) { + ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00322) + "WARNING: MinSpareThreads of %d not allowed, " + "increasing to 1 to avoid almost certain server failure. " + "Please read the documentation.", min_spare_threads); + } else { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00323) + "MinSpareThreads of %d not allowed, increasing to 1", + min_spare_threads); + } + min_spare_threads = 1; + } + + /* max_spare_threads < min_spare_threads + threads_per_child + * checked in worker_run() + */ + + return OK; +} + +static void worker_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}; + one_process = 0; + + ap_hook_open_logs(worker_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(worker_pre_config, NULL, NULL, APR_HOOK_REALLY_FIRST); + ap_hook_check_config(worker_check_config, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_mpm(worker_run, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_mpm_query(worker_query, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_mpm_get_name(worker_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_spare_threads(cmd_parms *cmd, void *dummy, + const char *arg) +{ + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + if (err != NULL) { + return err; + } + + min_spare_threads = atoi(arg); + return NULL; +} + +static const char *set_max_spare_threads(cmd_parms *cmd, void *dummy, + const char *arg) +{ + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + if (err != NULL) { + return err; + } + + max_spare_threads = atoi(arg); + return NULL; +} + +static const char *set_max_workers (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(00324) + "MaxClients is deprecated, use MaxRequestWorkers " + "instead."); + } + max_workers = atoi(arg); + return NULL; +} + +static const char *set_threads_per_child (cmd_parms *cmd, void *dummy, + const char *arg) +{ + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + if (err != NULL) { + return err; + } + + threads_per_child = 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 char *set_thread_limit (cmd_parms *cmd, void *dummy, const char *arg) +{ + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + if (err != NULL) { + return err; + } + + thread_limit = atoi(arg); + return NULL; +} + +static const command_rec worker_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("MinSpareThreads", set_min_spare_threads, NULL, RSRC_CONF, + "Minimum number of idle threads, to handle request spikes"), +AP_INIT_TAKE1("MaxSpareThreads", set_max_spare_threads, NULL, RSRC_CONF, + "Maximum number of idle threads"), +AP_INIT_TAKE1("MaxRequestWorkers", set_max_workers, NULL, RSRC_CONF, + "Maximum number of threads alive at the same time"), +AP_INIT_TAKE1("MaxClients", set_max_workers, NULL, RSRC_CONF, + "Deprecated name of MaxRequestWorkers"), +AP_INIT_TAKE1("ThreadsPerChild", set_threads_per_child, NULL, RSRC_CONF, + "Number of threads each child creates"), +AP_INIT_TAKE1("ServerLimit", set_server_limit, NULL, RSRC_CONF, + "Maximum number of child processes for this run of Apache"), +AP_INIT_TAKE1("ThreadLimit", set_thread_limit, NULL, RSRC_CONF, + "Maximum number of worker threads per child process for this run of Apache - Upper limit for ThreadsPerChild"), +AP_GRACEFUL_SHUTDOWN_TIMEOUT_COMMAND, +{ NULL } +}; + +AP_DECLARE_MODULE(mpm_worker) = { + 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 */ + worker_cmds, /* command apr_table_t */ + worker_hooks /* register_hooks */ +}; + |