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Diffstat (limited to 'rubbos/app/httpd-2.0.64/server/mpm/experimental/threadpool/threadpool.c')
| -rw-r--r-- | rubbos/app/httpd-2.0.64/server/mpm/experimental/threadpool/threadpool.c | 2229 |
1 files changed, 2229 insertions, 0 deletions
diff --git a/rubbos/app/httpd-2.0.64/server/mpm/experimental/threadpool/threadpool.c b/rubbos/app/httpd-2.0.64/server/mpm/experimental/threadpool/threadpool.c new file mode 100644 index 00000000..50de500e --- /dev/null +++ b/rubbos/app/httpd-2.0.64/server/mpm/experimental/threadpool/threadpool.c @@ -0,0 +1,2229 @@ +/* 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_poll.h" +#include "apr_thread_mutex.h" +#include "apr_thread_cond.h" +#include "apr_proc_mutex.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 + +#define CORE_PRIVATE + +#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 "pod.h" +#include "mpm_common.h" +#include "ap_listen.h" +#include "scoreboard.h" +#include "mpm_default.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 + */ + +int ap_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 server_limit = DEFAULT_SERVER_LIMIT; +static int first_server_limit; +static int thread_limit = DEFAULT_THREAD_LIMIT; +static int first_thread_limit; +static int changed_limit_at_restart; +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 int mpm_state = AP_MPMQ_STARTING; + +/* 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 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; + +static ap_pod_t *pod; + +/* *Non*-shared http_main globals... */ + +server_rec *ap_server_conf; + +/* 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 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; + +/* Locks for accept serialization */ +static apr_proc_mutex_t *accept_mutex; + +#if APR_O_NONBLOCK_INHERITED +#undef SINGLE_LISTEN_UNSERIALIZED_ACCEPT +#endif /* APR_O_NONBLOCK_INHERITED */ + +#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 + + +/* Possible states of a worker thread. */ +typedef enum { + WORKER_IDLE, + WORKER_BUSY, + WORKER_TERMINATED +} worker_state_e; + +/* Structure used to wake up an idle worker thread + */ +typedef struct { + apr_pool_t *pool; + apr_socket_t *csd; + worker_state_e state; + apr_thread_cond_t *cond; + apr_thread_mutex_t *mutex; +} worker_wakeup_info; + +/* Structure used to hold a stack of idle worker threads + */ +typedef struct { + apr_thread_mutex_t *mutex; + apr_thread_cond_t *cond; + worker_wakeup_info **stack; + apr_size_t nelts; + apr_size_t nalloc; + int terminated; +} worker_stack; + +static worker_stack* worker_stack_create(apr_pool_t *pool, apr_size_t max) +{ + apr_status_t rv; + worker_stack *stack = (worker_stack *)apr_palloc(pool, sizeof(*stack)); + + if ((rv = apr_thread_mutex_create(&stack->mutex, APR_THREAD_MUTEX_DEFAULT, + pool)) != APR_SUCCESS) { + return NULL; + } + if ((rv = apr_thread_cond_create(&stack->cond, pool)) != APR_SUCCESS) { + return NULL; + } + stack->nelts = 0; + stack->nalloc = max; + stack->stack = + (worker_wakeup_info **)apr_palloc(pool, stack->nalloc * + sizeof(worker_wakeup_info *)); + stack->terminated = 0; + return stack; +} + +static apr_status_t worker_stack_wait(worker_stack *stack, + worker_wakeup_info *wakeup) +{ + apr_status_t rv; + + wakeup->state = WORKER_IDLE; + + if ((rv = apr_thread_mutex_lock(stack->mutex)) != APR_SUCCESS) { + return rv; + } + if (stack->terminated) { + if ((rv = apr_thread_mutex_unlock(stack->mutex)) != APR_SUCCESS) { + return rv; + } + return APR_EOF; + } + if (stack->nelts == stack->nalloc) { + if ((rv = apr_thread_mutex_unlock(stack->mutex)) != APR_SUCCESS) { + return rv; + } + return APR_ENOSPC; + } + stack->stack[stack->nelts] = wakeup; + /* Signal a blocking listener thread only if we just made the + * stack non-empty. */ + if (stack->nelts++ == 0) { + (void)apr_thread_cond_signal(stack->cond); + } + if ((rv = apr_thread_mutex_unlock(stack->mutex)) != APR_SUCCESS) { + return rv; + } + + /* At this point we've already added this worker to the stack, now + * we just wait until the listener has accept()ed a connection + * for us. */ + if ((rv = apr_thread_mutex_lock(wakeup->mutex)) != APR_SUCCESS) { + return rv; + } + while (wakeup->state == WORKER_IDLE) { + if ((rv = apr_thread_cond_wait(wakeup->cond, wakeup->mutex)) != + APR_SUCCESS) { + return rv; + } + } + if ((rv = apr_thread_mutex_unlock(wakeup->mutex)) != APR_SUCCESS) { + return rv; + } + return APR_SUCCESS; +} + +static apr_status_t worker_stack_pop(worker_stack *stack, + worker_wakeup_info **worker) +{ + apr_status_t rv; + if ((rv = apr_thread_mutex_lock(stack->mutex)) != APR_SUCCESS) { + return rv; + } + AP_DEBUG_ASSERT(stack->nelts >= 0); + while ((stack->nelts == 0) && (!stack->terminated)) { + rv = apr_thread_cond_wait(stack->cond, stack->mutex); + if (rv != APR_SUCCESS) { + apr_status_t rv2; + rv2 = apr_thread_mutex_unlock(stack->mutex); + if (rv2 != APR_SUCCESS) { + return rv2; + } + return rv; + } + } + if (stack->terminated) { + if ((rv = apr_thread_mutex_unlock(stack->mutex)) != APR_SUCCESS) { + return rv; + } + return APR_EOF; + } + *worker = stack->stack[--stack->nelts]; + if ((rv = apr_thread_mutex_unlock(stack->mutex)) != APR_SUCCESS) { + return rv; + } + return APR_SUCCESS; +} + +static apr_status_t worker_stack_terminate(worker_stack *stack) +{ + apr_status_t rv; + worker_wakeup_info *worker; + + if ((rv = apr_thread_mutex_lock(stack->mutex)) != APR_SUCCESS) { + return rv; + } + stack->terminated = 1; + /* Wake up the listener thread. Although there will never be + * more than one thread blocking on this condition, broadcast + * just in case. */ + apr_thread_cond_broadcast(stack->cond); + while (stack->nelts) { + worker = stack->stack[--stack->nelts]; + apr_thread_mutex_lock(worker->mutex); + worker->csd = 0; + worker->state = WORKER_TERMINATED; + apr_thread_cond_signal(worker->cond); + apr_thread_mutex_unlock(worker->mutex); + } + if ((rv = apr_thread_mutex_unlock(stack->mutex)) != APR_SUCCESS) { + return rv; + } + return APR_SUCCESS; +} + +static worker_stack *idle_worker_stack; + +static void wakeup_listener(void) +{ + apr_status_t rv; + + listener_may_exit = 1; + if (!idle_worker_stack) { + return; + } + if ((rv = apr_thread_mutex_lock(idle_worker_stack->mutex)) != APR_SUCCESS) { + return; + } + if ((rv = apr_thread_cond_signal(idle_worker_stack->cond)) != + APR_SUCCESS) { + return; + } + if ((rv = apr_thread_mutex_unlock(idle_worker_stack->mutex)) != APR_SUCCESS) { + return; + } + 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; + } + /* + * 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; + 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; + worker_stack_terminate(idle_worker_stack); + } +} + +AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result) +{ + switch(query_code){ + case AP_MPMQ_MAX_DAEMON_USED: + *result = ap_max_daemons_limit; + return APR_SUCCESS; + case AP_MPMQ_IS_THREADED: + *result = AP_MPMQ_STATIC; + 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 = thread_limit; + return APR_SUCCESS; + case AP_MPMQ_MAX_THREADS: + *result = ap_threads_per_child; + return APR_SUCCESS; + case AP_MPMQ_MIN_SPARE_DAEMONS: + *result = 0; + return APR_SUCCESS; + case AP_MPMQ_MIN_SPARE_THREADS: + *result = min_spare_threads; + return APR_SUCCESS; + case AP_MPMQ_MAX_SPARE_DAEMONS: + *result = 0; + return APR_SUCCESS; + case AP_MPMQ_MAX_SPARE_THREADS: + *result = max_spare_threads; + return APR_SUCCESS; + case AP_MPMQ_MAX_REQUESTS_DAEMON: + *result = ap_max_requests_per_child; + return APR_SUCCESS; + case AP_MPMQ_MAX_DAEMONS: + *result = ap_daemons_limit; + return APR_SUCCESS; + case AP_MPMQ_MPM_STATE: + *result = mpm_state; + return APR_SUCCESS; + } + return APR_ENOTIMPL; +} + +/* 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); + } + exit(code); +} + +static void just_die(int sig) +{ + clean_child_exit(0); +} + +/***************************************************************** + * Connection structures and accounting... + */ + +/* volatile just in case */ +static int volatile shutdown_pending; +static int volatile restart_pending; +static int volatile is_graceful; +static volatile int child_fatal; +ap_generation_t volatile ap_my_generation; + +/* + * ap_start_shutdown() and ap_start_restart(), below, are a first stab at + * functions to initiate shutdown or restart without relying on signals. + * Previously this was initiated in sig_term() and restart() signal handlers, + * but we want to be able to start a shutdown/restart from other sources -- + * e.g. on Win32, from the service manager. Now the service manager can + * call ap_start_shutdown() or ap_start_restart() as appropiate. Note that + * these functions can also be called by the child processes, since global + * variables are no longer used to pass on the required action to the parent. + * + * These should only be called from the parent process itself, since the + * parent process will use the shutdown_pending and restart_pending variables + * to determine whether to shutdown or restart. The child process should + * call signal_parent() directly to tell the parent to die -- this will + * cause neither of those variable to be set, which the parent will + * assume means something serious is wrong (which it will be, for the + * child to force an exit) and so do an exit anyway. + */ + +static void ap_start_shutdown(void) +{ + mpm_state = AP_MPMQ_STOPPING; + 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; +} + +/* do a graceful restart if graceful == 1 */ +static void ap_start_restart(int graceful) +{ + mpm_state = AP_MPMQ_STOPPING; + if (restart_pending == 1) { + /* Probably not an error - don't bother reporting it */ + return; + } + restart_pending = 1; + is_graceful = graceful; +} + +static void sig_term(int sig) +{ + ap_start_shutdown(); +} + +static void restart(int sig) +{ + ap_start_restart(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 +} + +/***************************************************************** + * Here follows a long bunch of generic server bookkeeping stuff... + */ + +int ap_graceful_stop_signalled(void) + /* XXX this is really a bad confusing obsolete name + * maybe it should be ap_mpm_process_exiting? + */ +{ + /* note: for a graceful termination, listener_may_exit will be set before + * workers_may_exit, so check listener_may_exit + */ + return listener_may_exit; +} + +/***************************************************************** + * Child process main loop. + */ + +static void process_socket(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); + int csd; + ap_sb_handle_t *sbh; + + ap_create_sb_handle(&sbh, p, my_child_num, my_thread_num); + apr_os_sock_get(&csd, sock); + + current_conn = ap_run_create_connection(p, ap_server_conf, sock, + conn_id, sbh, bucket_alloc); + if (current_conn) { + 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 + "MaxRequestsPerChild 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 { + /* wow! if you're executing this code, you may have set a record. + * either this child process has served over 2 billion requests, or + * you're running a threaded 2.0 on a 16 bit machine. + * + * I'll buy pizza and beers at Apachecon for the first person to do + * the former without cheating (dorking with INT_MAX, or running with + * uncommitted performance patches, for example). + * + * for the latter case, you probably deserve a beer too. Greg Ames + */ + + 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 *listener_thread(apr_thread_t *thd, void * dummy) +{ + proc_info * ti = dummy; + int process_slot = ti->pid; + apr_pool_t *tpool = apr_thread_pool_get(thd); + void *csd = NULL; + apr_pool_t *ptrans; /* Pool for per-transaction stuff */ + int n; + apr_pollfd_t *pollset; + apr_status_t rv; + ap_listen_rec *lr, *last_lr = ap_listeners; + worker_wakeup_info *worker = NULL; + + free(ti); + + apr_poll_setup(&pollset, num_listensocks, tpool); + for(lr = ap_listeners ; lr != NULL ; lr = lr->next) + apr_poll_socket_add(pollset, lr->sd, APR_POLLIN); + + /* Unblock the signal used to wake this thread up, and set a handler for + * it. + */ + unblock_signal(LISTENER_SIGNAL); + apr_signal(LISTENER_SIGNAL, dummy_signal_handler); + + /* 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 (worker == NULL) { + rv = worker_stack_pop(idle_worker_stack, &worker); + if (APR_STATUS_IS_EOF(rv)) { + break; + } + else if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf, + "worker_stack_pop failed"); + break; + } + ptrans = worker->pool; + } + AP_DEBUG_ASSERT(worker->state == WORKER_IDLE); + + if ((rv = SAFE_ACCEPT(apr_proc_mutex_lock(accept_mutex))) + != APR_SUCCESS) { + int level = APLOG_EMERG; + + if (listener_may_exit) { + break; + } + 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, + "apr_proc_mutex_lock failed. Attempting to shutdown " + "process gracefully."); + signal_threads(ST_GRACEFUL); + break; /* skip the lock release */ + } + + if (!APR_O_NONBLOCK_INHERITED && !ap_listeners->next) { + /* Only one listener, so skip the poll */ + lr = ap_listeners; + } + else { + while (!listener_may_exit) { + apr_status_t ret; + apr_int16_t event; + + ret = apr_poll(pollset, num_listensocks, &n, -1); + if (ret != APR_SUCCESS) { + if (APR_STATUS_IS_EINTR(ret)) { + continue; + } + + /* apr_poll() will only return errors in catastrophic + * circumstances. Let's try exiting gracefully, for now. */ + ap_log_error(APLOG_MARK, APLOG_ERR, ret, (const server_rec *) + ap_server_conf, "apr_poll: (listen)"); + signal_threads(ST_GRACEFUL); + } + + if (listener_may_exit) break; + + /* find a listener */ + lr = last_lr; + do { + lr = lr->next; + if (lr == NULL) { + lr = ap_listeners; + } + /* XXX: Should we check for POLLERR? */ + apr_poll_revents_get(&event, lr->sd, pollset); + if (event & APR_POLLIN) { + last_lr = lr; + goto got_fd; + } + } while (lr != last_lr); + } + } + got_fd: + if (!listener_may_exit) { + 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(accept_mutex))) + != APR_SUCCESS) { + int level = APLOG_EMERG; + + if (listener_may_exit) { + break; + } + 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, + "apr_proc_mutex_unlock failed. Attempting to " + "shutdown process gracefully."); + signal_threads(ST_GRACEFUL); + } + if (csd != NULL) { + /* Wake up the sleeping worker. */ + apr_thread_mutex_lock(worker->mutex); + worker->csd = (apr_socket_t *)csd; + worker->state = WORKER_BUSY; + /* Posix allows us to signal this condition without + * owning the associated mutex, but in that case it can + * not guarantee predictable scheduling. See + * _UNIX Network Programming: Interprocess Communication_ + * by W. Richard Stevens, Vol 2, 2nd Ed, pp. 170-171. */ + apr_thread_cond_signal(worker->cond); + apr_thread_mutex_unlock(worker->mutex); + worker = NULL; + } + } + else { + if ((rv = SAFE_ACCEPT(apr_proc_mutex_unlock(accept_mutex))) + != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, + "apr_proc_mutex_unlock failed. Attempting to " + "shutdown process gracefully."); + signal_threads(ST_GRACEFUL); + } + break; + } + } + + workers_may_exit = 1; + if (worker) { + apr_thread_mutex_lock(worker->mutex); + worker->state = WORKER_TERMINATED; + /* Posix allows us to signal this condition without + * owning the associated mutex, but in that case it can + * not guarantee predictable scheduling. See + * _UNIX Network Programming: Interprocess Communication_ + * by W. Richard Stevens, Vol 2, 2nd Ed, pp. 170-171. */ + apr_thread_cond_signal(worker->cond); + apr_thread_mutex_unlock(worker->mutex); + } + worker_stack_terminate(idle_worker_stack); + 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_bucket_alloc_t *bucket_alloc; + apr_pool_t *tpool = apr_thread_pool_get(thd); + apr_pool_t *ptrans; /* Pool for per-transaction stuff */ + apr_allocator_t *allocator; + apr_status_t rv; + worker_wakeup_info *wakeup; + + free(ti); + + ap_update_child_status_from_indexes(process_slot, thread_slot, SERVER_STARTING, NULL); + + apr_allocator_create(&allocator); + apr_allocator_max_free_set(allocator, ap_max_mem_free); + /* XXX: why is ptrans's parent not tpool? --jcw 08/2003 */ + apr_pool_create_ex(&ptrans, NULL, NULL, allocator); + apr_allocator_owner_set(allocator, ptrans); + bucket_alloc = apr_bucket_alloc_create_ex(allocator); + + wakeup = (worker_wakeup_info *)apr_palloc(tpool, sizeof(*wakeup)); + wakeup->pool = ptrans; + if ((rv = apr_thread_cond_create(&wakeup->cond, tpool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, + "apr_thread_cond_create failed. Attempting to shutdown " + "process gracefully."); + signal_threads(ST_GRACEFUL); + apr_thread_exit(thd, rv); + } + if ((rv = apr_thread_mutex_create(&wakeup->mutex, APR_THREAD_MUTEX_DEFAULT, + tpool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, + "apr_thread_mutex_create failed. Attempting to shutdown " + "process gracefully."); + signal_threads(ST_GRACEFUL); + apr_thread_exit(thd, rv); + } + + while (!workers_may_exit) { + ap_update_child_status_from_indexes(process_slot, thread_slot, SERVER_READY, NULL); + rv = worker_stack_wait(idle_worker_stack, wakeup); + if (APR_STATUS_IS_EOF(rv)) { + break; /* The queue has been terminated. */ + } + else if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf, + "worker_stack_wait failed"); + break; /* Treat all other errors as fatal. */ + } + else if (wakeup->state == WORKER_TERMINATED) { + break; /* They told us to quit. */ + } + AP_DEBUG_ASSERT(wakeup->state != WORKER_IDLE); + process_socket(ptrans, wakeup->csd, + process_slot, thread_slot, bucket_alloc); + requests_this_child--; /* FIXME: should be synchronized - aaron */ + apr_pool_clear(ptrans); + } + + ap_update_child_status_from_indexes(process_slot, thread_slot, + (dying) ? SERVER_DEAD : SERVER_GRACEFUL, (request_rec *) NULL); + + apr_bucket_alloc_destroy(bucket_alloc); + + 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 *)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 = apr_thread_create(&ts->listener, thread_attr, listener_thread, + my_info, pchild); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf, + "apr_thread_create: unable to create listener thread"); + /* 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 if we exit. + * XXX Jeff doesn't see how Apache is going to try to fork again since + * the exit code is APEXIT_CHILDFATAL + */ + apr_sleep(10 * APR_USEC_PER_SEC); + clean_child_exit(APEXIT_CHILDFATAL); + } + apr_os_thread_get(&listener_os_thread, ts->listener); +} + +/* 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 child_num_arg = ts->child_num_arg; + int my_child_num = child_num_arg; + proc_info *my_info; + apr_status_t rv; + int i; + int threads_created = 0; + int loops; + int prev_threads_created; + + idle_worker_stack = worker_stack_create(pchild, ap_threads_per_child); + if (idle_worker_stack == NULL) { + ap_log_error(APLOG_MARK, APLOG_ALERT, 0, ap_server_conf, + "worker_stack_create() failed"); + clean_child_exit(APEXIT_CHILDFATAL); + } + + loops = prev_threads_created = 0; + while (1) { + /* ap_threads_per_child does not include the listener thread */ + for (i = 0; i < ap_threads_per_child; i++) { + int status = ap_scoreboard_image->servers[child_num_arg][i].status; + + if (status != SERVER_GRACEFUL && status != SERVER_DEAD) { + continue; + } + + my_info = (proc_info *)malloc(sizeof(proc_info)); + if (my_info == NULL) { + ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf, + "malloc: out of memory"); + clean_child_exit(APEXIT_CHILDFATAL); + } + 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 = apr_thread_create(&threads[i], thread_attr, + worker_thread, my_info, pchild); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf, + "apr_thread_create: unable to create worker thread"); + /* 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 if we exit. */ + apr_sleep(10 * APR_USEC_PER_SEC); + clean_child_exit(APEXIT_CHILDFATAL); + } + threads_created++; + if (threads_created == 1) { + /* now that we have a worker thread, it makes sense to create + * a listener thread (we don't want a listener without a worker!) + */ + create_listener_thread(ts); + } + } + if (start_thread_may_exit || threads_created == ap_threads_per_child) { + break; + } + /* wait for previous generation to clean up an entry */ + apr_sleep(1 * APR_USEC_PER_SEC); + ++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, ap_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 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_USEC_PER_SEC / 2); + wakeup_listener(); + ++iter; + } + if (iter >= 10) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, + "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, + "apr_thread_join: unable to join listener thread"); + } + } + } + + for (i = 0; i < ap_threads_per_child; i++) { + if (threads[i]) { /* if we ever created this thread */ + rv = apr_thread_join(&thread_rv, threads[i]); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf, + "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, + "apr_thread_join: unable to join the start " + "thread"); + } +} + +static void child_main(int child_num_arg) +{ + apr_thread_t **threads; + apr_status_t rv; + thread_starter *ts; + apr_threadattr_t *thread_attr; + apr_thread_t *start_thread_id; + + mpm_state = AP_MPMQ_STARTING; /* for benefit of any hooks that run as this + * child initializes + */ + ap_my_pid = getpid(); + ap_fatal_signal_child_setup(ap_server_conf); + apr_pool_create(&pchild, pconf); + + /*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(&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); + + /* done with init critical section */ + + /* 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. + */ + rv = apr_setup_signal_thread(); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, + "Couldn't initialize signal thread"); + clean_child_exit(APEXIT_CHILDFATAL); + } + + 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 worker threads */ + + /* 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 **)calloc(1, + sizeof(apr_thread_t *) * ap_threads_per_child); + if (threads == NULL) { + ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf, + "malloc: out of memory"); + clean_child_exit(APEXIT_CHILDFATAL); + } + + 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); + + ts->threads = threads; + ts->listener = NULL; + ts->child_num_arg = child_num_arg; + ts->threadattr = thread_attr; + + rv = apr_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, + "apr_thread_create: unable to create worker thread"); + /* 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 if we exit. */ + apr_sleep(10 * APR_USEC_PER_SEC); + clean_child_exit(APEXIT_CHILDFATAL); + } + + 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); + } + 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 MaxRequestsPerChild) it will send us SIGTERM + */ + unblock_signal(SIGTERM); + apr_signal(SIGTERM, dummy_signal_handler); + /* Watch for any messages from the parent over the POD */ + while (1) { + rv = ap_mpm_pod_check(pod); + if (rv == AP_NORESTART) { + /* see if termination was triggered while we slept */ + switch(terminate_mode) { + case ST_GRACEFUL: + rv = AP_GRACEFUL; + break; + case ST_UNGRACEFUL: + rv = AP_RESTART; + break; + } + } + if (rv == AP_GRACEFUL || rv == AP_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_GRACEFUL ? ST_GRACEFUL : ST_UNGRACEFUL); + break; + } + } + + if (rv == AP_GRACEFUL) { + /* 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); + } + } + + free(threads); + + clean_child_exit(resource_shortage ? APEXIT_CHILDSICK : 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) { + set_signals(); + ap_scoreboard_image->parent[slot].pid = getpid(); + child_main(slot); + } + + if ((pid = fork()) == -1) { + 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 + */ + ap_update_child_status_from_indexes(slot, 0, SERVER_DEAD, 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. */ + apr_sleep(10 * APR_USEC_PER_SEC); + + 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); + + apr_signal(SIGTERM, just_die); + child_main(slot); + + clean_child_exit(0); + } + /* else */ + ap_scoreboard_image->parent[slot].quiescing = 0; + 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->parent[i].pid != 0) { + 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(void) +{ + int i, j; + int idle_thread_count; + worker_score *ws; + 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; + + /* 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 ap_threads_per_child is always > 0 */ + int status = SERVER_DEAD; + int any_dying_threads = 0; + int any_dead_threads = 0; + int all_dead_threads = 1; + + if (i >= ap_max_daemons_limit && totally_free_length == idle_spawn_rate) + break; + ps = &ap_scoreboard_image->parent[i]; + for (j = 0; j < ap_threads_per_child; j++) { + ws = &ap_scoreboard_image->servers[i][j]; + status = ws->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 (status <= SERVER_READY && status != SERVER_DEAD && + !ps->quiescing && + ps->generation == ap_my_generation && + /* XXX the following shouldn't be necessary if we clean up + * properly after seg faults, but we're not yet GLA + */ + ps->pid != 0) { + ++idle_thread_count; + } + } + if (any_dead_threads && totally_free_length < idle_spawn_rate + && (!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; + } + /* XXX if (!ps->quiescing) is probably more reliable GLA */ + if (!any_dying_threads) { + last_non_dead = i; + ++total_non_dead; + } + } + ap_max_daemons_limit = last_non_dead + 1; + + if (idle_thread_count > max_spare_threads) { + /* Kill off one child */ + ap_mpm_pod_signal(pod, TRUE); + idle_spawn_rate = 1; + } + else if (idle_thread_count < min_spare_threads) { + /* 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 (free_length > idle_spawn_rate) { + free_length = idle_spawn_rate; + } + 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, 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]); + } + /* 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; + } +} + +static void server_main_loop(int remaining_children_to_start) +{ + int child_slot; + apr_exit_why_e exitwhy; + int status, processed_status; + apr_proc_t pid; + int i; + + while (!restart_pending && !shutdown_pending) { + ap_wait_or_timeout(&exitwhy, &status, &pid, pconf); + + if (pid.pid != -1) { + processed_status = ap_process_child_status(&pid, exitwhy, status); + if (processed_status == APEXIT_CHILDFATAL) { + shutdown_pending = 1; + child_fatal = 1; + return; + } + /* non-fatal death... note that it's gone in the scoreboard. */ + child_slot = find_child_by_pid(&pid); + if (child_slot >= 0) { + for (i = 0; i < ap_threads_per_child; i++) + ap_update_child_status_from_indexes(child_slot, i, SERVER_DEAD, + (request_rec *) NULL); + + ap_scoreboard_image->parent[child_slot].pid = 0; + ap_scoreboard_image->parent[child_slot].quiescing = 0; + if (processed_status == APEXIT_CHILDSICK) { + /* resource shortage, minimize the fork rate */ + 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(); + } +} + +int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) +{ + int remaining_children_to_start; + apr_status_t rv; + + ap_log_pid(pconf, ap_pid_fname); + + first_server_limit = server_limit; + first_thread_limit = thread_limit; + if (changed_limit_at_restart) { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, + "WARNING: Attempt to change ServerLimit or ThreadLimit " + "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(); + /* Don't thrash... */ + if (max_spare_threads < min_spare_threads + ap_threads_per_child) + max_spare_threads = min_spare_threads + ap_threads_per_child; + + /* 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; + + server_main_loop(remaining_children_to_start); + mpm_state = AP_MPMQ_STOPPING; + + if (shutdown_pending) { + /* Time to gracefully shut down: + * Kill child processes, tell them to call child_exit, etc... + * (By "gracefully" we don't mean graceful in the same sense as + * "apachectl graceful" where we allow old connections to finish.) + */ + ap_mpm_pod_killpg(pod, ap_daemons_limit, FALSE); + ap_reclaim_child_processes(1); /* Start with SIGTERM */ + + if (!child_fatal) { + /* 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, + AP_SIG_GRACEFUL_STRING " received. Doing graceful restart"); + /* wake up the children...time to die. But we'll have more soon */ + ap_mpm_pod_killpg(pod, ap_daemons_limit, TRUE); + + + /* 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. + */ + ap_mpm_pod_killpg(pod, ap_daemons_limit, FALSE); + + ap_reclaim_child_processes(1); /* Start with SIGTERM */ + 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 worker_open_logs(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s) +{ + apr_status_t rv; + ap_listen_rec *lr; + + 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 APR_O_NONBLOCK_INHERITED + for(lr = ap_listeners ; lr != NULL ; lr = lr->next) { + apr_socket_opt_set(lr->sd, APR_SO_NONBLOCK, 1); + } +#endif /* APR_O_NONBLOCK_INHERITED */ + + if (!one_process) { + 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 worker_pre_config(apr_pool_t *pconf, apr_pool_t *plog, + apr_pool_t *ptemp) +{ + static int restart_num = 0; + int no_detach, debug, foreground; + ap_directive_t *pdir; + ap_directive_t *max_clients = NULL; + apr_status_t rv; + + mpm_state = AP_MPMQ_STARTING; + + /* make sure that "ThreadsPerChild" gets set before "MaxClients" */ + for (pdir = ap_conftree; pdir != NULL; pdir = pdir->next) { + if (strncasecmp(pdir->directive, "ThreadsPerChild", 15) == 0) { + if (!max_clients) { + break; /* we're in the clear, got ThreadsPerChild first */ + } + else { + /* now to swap the data */ + ap_directive_t temp; + + temp.directive = pdir->directive; + temp.args = pdir->args; + /* Make sure you don't change 'next', or you may get loops! */ + /* XXX: first_child, parent, and data can never be set + * for these directives, right? -aaron */ + temp.filename = pdir->filename; + temp.line_num = pdir->line_num; + + pdir->directive = max_clients->directive; + pdir->args = max_clients->args; + pdir->filename = max_clients->filename; + pdir->line_num = max_clients->line_num; + + max_clients->directive = temp.directive; + max_clients->args = temp.args; + max_clients->filename = temp.filename; + max_clients->line_num = temp.line_num; + break; + } + } + else if (!max_clients + && strncasecmp(pdir->directive, "MaxClients", 10) == 0) { + max_clients = pdir; + } + } + + 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"); + } + + /* 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; + min_spare_threads = DEFAULT_MIN_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD; + max_spare_threads = DEFAULT_MAX_FREE_DAEMON * DEFAULT_THREADS_PER_CHILD; + ap_daemons_limit = server_limit; + ap_threads_per_child = DEFAULT_THREADS_PER_CHILD; + 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 threadpool_hooks(apr_pool_t *p) +{ + /* The worker 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}; + one_process = 0; + + ap_hook_open_logs(worker_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(worker_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_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); + if (min_spare_threads <= 0) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: detected MinSpareThreads 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."); + min_spare_threads = 1; + } + + 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_clients (cmd_parms *cmd, void *dummy, + const char *arg) +{ + int max_clients; + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + if (err != NULL) { + return err; + } + + /* It is ok to use ap_threads_per_child here because we are + * sure that it gets set before MaxClients in the pre_config stage. */ + max_clients = atoi(arg); + if (max_clients < ap_threads_per_child) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: MaxClients (%d) must be at least as large", + max_clients); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " large as ThreadsPerChild (%d). Automatically", + ap_threads_per_child); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " increasing MaxClients to %d.", + ap_threads_per_child); + max_clients = ap_threads_per_child; + } + ap_daemons_limit = max_clients / ap_threads_per_child; + if ((max_clients > 0) && (max_clients % ap_threads_per_child)) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: MaxClients (%d) is not an integer multiple", + max_clients); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " of ThreadsPerChild (%d), lowering MaxClients to %d", + ap_threads_per_child, + ap_daemons_limit * ap_threads_per_child); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " for a maximum of %d child processes,", + ap_daemons_limit); + max_clients = ap_daemons_limit * ap_threads_per_child; + } + if (ap_daemons_limit > server_limit) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: MaxClients of %d would require %d servers,", + max_clients, ap_daemons_limit); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " and would exceed the ServerLimit value of %d.", + server_limit); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " Automatically lowering MaxClients to %d. To increase,", + server_limit * ap_threads_per_child); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " please see the ServerLimit 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_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; + } + + ap_threads_per_child = atoi(arg); + if (ap_threads_per_child > thread_limit) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: ThreadsPerChild of %d exceeds ThreadLimit " + "value of %d", ap_threads_per_child, + thread_limit); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "threads, lowering ThreadsPerChild to %d. To increase, please" + " see the", thread_limit); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " ThreadLimit directive."); + ap_threads_per_child = thread_limit; + } + else if (ap_threads_per_child < 1) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: Require ThreadsPerChild > 0, setting to 1"); + ap_threads_per_child = 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 char *set_thread_limit (cmd_parms *cmd, void *dummy, const char *arg) +{ + int tmp_thread_limit; + + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + if (err != NULL) { + return err; + } + + tmp_thread_limit = atoi(arg); + /* you cannot change ThreadLimit across a restart; ignore + * any such attempts + */ + if (first_thread_limit && + tmp_thread_limit != thread_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; + } + thread_limit = tmp_thread_limit; + + if (thread_limit > MAX_THREAD_LIMIT) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: ThreadLimit of %d exceeds compile time limit " + "of %d servers,", thread_limit, MAX_THREAD_LIMIT); + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + " lowering ThreadLimit to %d.", MAX_THREAD_LIMIT); + thread_limit = MAX_THREAD_LIMIT; + } + else if (thread_limit < 1) { + ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, + "WARNING: Require ThreadLimit > 0, setting to 1"); + thread_limit = 1; + } + return NULL; +} + +static const command_rec threadpool_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("MinSpareThreads", set_min_spare_threads, NULL, RSRC_CONF, + "Minimum number of idle children, to handle request spikes"), +AP_INIT_TAKE1("MaxSpareThreads", set_max_spare_threads, 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("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 value of MaxClients for this run of Apache"), +AP_INIT_TAKE1("ThreadLimit", set_thread_limit, NULL, RSRC_CONF, + "Maximum worker threads in a server for this run of Apache"), +{ NULL } +}; + +module AP_MODULE_DECLARE_DATA mpm_threadpool_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 */ + threadpool_cmds, /* command apr_table_t */ + threadpool_hooks /* register_hooks */ +}; + |