Hey, it serves pages on my Linux 2.4/glibc-2.2 box. This is a proof-of-concept. Would any committer (remember, I'm not a committer to httpd-2.0) be interested in committing a working and clean spmt MPM if I submitted one? On Roy's suggestion, I looked at the dexter MPM, but it had the capability of having additional children (making it mpmt). That was something I wanted to avoid. Only *one* process should have threads to serve pages. Currently, it is a separate child process from the original httpd process, but that gives some level of robustness. I can easily take that out though. I didn't bother getting the cleanup mechanisms right or making sure that the scoreboard is correct. Altogether, fairly trivial things, but they take time to code right. I tried to focus on getting it to serve pages correctly and condensing the mainline code. To bootstrap this, I basically took the threaded MPM and threw out most of the parts that relate to making multiple children. A lot of the other cruft not in the mainline in threaded MPM (i.e. the config syntax) is unchanged. -- justin
/* ==================================================================== * The Apache Software License, Version 1.1 * * Copyright (c) 2000-2001 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. 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IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * * Portions of this software are based upon public domain software * originally written at the National Center for Supercomputing Applications, * University of Illinois, Urbana-Champaign. */ #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" #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 threaded 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 "unixd.h" #include "mpm_common.h" #include "ap_listen.h" #include "scoreboard.h" #include <signal.h> #include <limits.h> /* for INT_MAX */ /* * Actual definitions of config globals */ int ap_threads_per_child=0; /* Worker threads per child */ static int ap_max_requests_per_child=0; static const char *ap_pid_fname=NULL; 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 dying = 0; static int workers_may_exit = 0; static int requests_this_child; static int num_listensocks = 0; static apr_socket_t **listensocks; /* The structure used to pass unique initialization info to each thread */ typedef struct { int pid; int tid; int sd; apr_pool_t *tpool; /* "pthread" would be confusing */ } proc_info; /* Structure used to pass information to the thread responsible for * creating the rest of the threads. */ typedef struct { apr_thread_t **threads; int child_num_arg; apr_threadattr_t *threadattr; } thread_starter; /* * The max child slot ever assigned, preserved across restarts. Necessary * to deal with MaxClients changes across SIGWINCH restarts. We use this * value to optimize routines that have to scan the entire scoreboard. */ int ap_max_daemons_limit = -1; char ap_coredump_dir[MAX_STRING_LEN]; static apr_file_t *pipe_of_death_in = NULL; static apr_file_t *pipe_of_death_out = NULL; static apr_lock_t *pipe_of_death_mutex; /* insures that a child process only consumes one character */ /* *Non*-shared http_main globals... */ server_rec *ap_server_conf; /* one_process --- debugging mode variable; can be set from the command line * with the -X flag. If set, this gets you the child_main loop running * in the process which originally started up (no detach, no make_child), * which is a pretty nice debugging environment. (You'll get a SIGHUP * early in standalone_main; just continue through. This is the server * trying to kill off any child processes which it might have lying * around --- Apache doesn't keep track of their pids, it just sends * SIGHUP to the process group, ignoring it in the root process. * Continue through and you'll be fine.). */ static int one_process = 0; #ifdef DEBUG_SIGSTOP int raise_sigstop_flags; #endif static apr_pool_t *pconf; /* Pool for config stuff */ static apr_pool_t *pproc; /* Pool for httpd child stuff */ static pid_t ap_my_pid; /* Linux getpid() doesn't work except in main thread. Use this instead */ /* Keep track of the number of worker threads currently active */ static int worker_thread_count; static apr_lock_t *worker_thread_count_mutex; /* Locks for accept serialization */ static apr_lock_t *accept_mutex; static apr_lockmech_e_np accept_lock_mech = APR_LOCK_DEFAULT; static const char *lock_fname; #ifdef NO_SERIALIZED_ACCEPT #define SAFE_ACCEPT(stmt) APR_SUCCESS #else #define SAFE_ACCEPT(stmt) (stmt) #endif AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result) { switch(query_code){ case AP_MPMQ_MAX_DAEMON_USED: *result = ap_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 = HARD_SERVER_LIMIT; return APR_SUCCESS; case AP_MPMQ_HARD_LIMIT_THREADS: *result = HARD_THREAD_LIMIT; return APR_SUCCESS; case AP_MPMQ_MAX_THREADS: *result = ap_threads_per_child; return APR_SUCCESS; case AP_MPMQ_MIN_SPARE_DEAMONS: *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_DEAMON: *result = ap_max_requests_per_child; return APR_SUCCESS; case AP_MPMQ_MAX_DAEMONS: *result = ap_daemons_limit; 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) { if (pproc) { apr_pool_destroy(pproc); } exit(code); } /* handle all varieties of core dumping signals */ static void sig_coredump(int sig) { chdir(ap_coredump_dir); apr_signal(sig, SIG_DFL); kill(ap_my_pid, sig); /* At this point we've got sig blocked, because we're still inside * the signal handler. When we leave the signal handler it will * be unblocked, and we'll take the signal... and coredump or whatever * is appropriate for this particular Unix. In addition the parent * will see the real signal we received -- whereas if we called * abort() here, the parent would only see SIGABRT. */ } 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; 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) { 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) { if (restart_pending == 1) { /* Probably not an error - don't bother reporting it */ return; } restart_pending = 1; is_graceful = graceful; if (is_graceful) { apr_pool_cleanup_kill(pconf, NULL, ap_cleanup_scoreboard); } } static void sig_term(int sig) { ap_start_shutdown(); } static void restart(int sig) { ap_start_restart(sig == SIGWINCH); } static void set_signals(void) { #ifndef NO_USE_SIGACTION struct sigaction sa; sigemptyset(&sa.sa_mask); sa.sa_flags = 0; if (!one_process) { sa.sa_handler = sig_coredump; #if defined(SA_ONESHOT) sa.sa_flags = SA_ONESHOT; #elif defined(SA_RESETHAND) sa.sa_flags = SA_RESETHAND; #endif if (sigaction(SIGSEGV, &sa, NULL) < 0) ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGSEGV)"); #ifdef SIGBUS if (sigaction(SIGBUS, &sa, NULL) < 0) ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGBUS)"); #endif #ifdef SIGABORT if (sigaction(SIGABORT, &sa, NULL) < 0) ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGABORT)"); #endif #ifdef SIGABRT if (sigaction(SIGABRT, &sa, NULL) < 0) ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGABRT)"); #endif #ifdef SIGILL if (sigaction(SIGILL, &sa, NULL) < 0) ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGILL)"); #endif 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 WINCH while we're busy processing one */ sigaddset(&sa.sa_mask, SIGHUP); sigaddset(&sa.sa_mask, SIGWINCH); 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(SIGWINCH, &sa, NULL) < 0) ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGWINCH)"); #else if (!one_process) { apr_signal(SIGSEGV, sig_coredump); #ifdef SIGBUS apr_signal(SIGBUS, sig_coredump); #endif /* SIGBUS */ #ifdef SIGABORT apr_signal(SIGABORT, sig_coredump); #endif /* SIGABORT */ #ifdef SIGABRT apr_signal(SIGABRT, sig_coredump); #endif /* SIGABRT */ #ifdef SIGILL apr_signal(SIGILL, sig_coredump); #endif /* SIGILL */ #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 SIGWINCH apr_signal(SIGWINCH, restart); #endif /* SIGWINCH */ #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 - Does this really work? - Manoj */ return is_graceful; } /***************************************************************** * Child process main loop. */ static void process_socket(apr_pool_t *p, apr_socket_t *sock, int my_child_num, int my_thread_num) { conn_rec *current_conn; long conn_id = AP_ID_FROM_CHILD_THREAD(my_child_num, my_thread_num); int csd; (void) apr_os_sock_get(&csd, sock); if (csd >= FD_SETSIZE) { ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, 0, NULL, "new file descriptor %d is too large; you probably need " "to rebuild Apache with a larger FD_SETSIZE " "(currently %d)", csd, FD_SETSIZE); apr_socket_close(sock); return; } ap_sock_disable_nagle(sock); current_conn = ap_new_connection(p, ap_server_conf, sock, conn_id); if (current_conn) { ap_process_connection(current_conn); 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) { workers_may_exit = 1; } 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 */ } } /* Sets workers_may_exit if we received a character on the pipe_of_death */ static void check_pipe_of_death(void) { apr_lock_acquire(pipe_of_death_mutex); if (!workers_may_exit) { apr_status_t ret; char pipe_read_char; apr_size_t n = 1; ret = apr_recv(listensocks[0], &pipe_read_char, &n); if (APR_STATUS_IS_EAGAIN(ret)) { /* It lost the lottery. It must continue to suffer * through a life of servitude. */ } else { /* It won the lottery (or something else is very * wrong). Embrace death with open arms. */ if (n == 1) workers_may_exit = 1; } } apr_lock_release(pipe_of_death_mutex); } static void * worker_thread(void * dummy) { proc_info * ti = dummy; int process_slot = ti->pid; int thread_slot = ti->tid; apr_pool_t *tpool = ti->tpool; apr_socket_t *csd = NULL; apr_pool_t *ptrans; /* Pool for per-transaction stuff */ apr_socket_t *sd = NULL; int n; int curr_pollfd, last_pollfd = 0; apr_pollfd_t *pollset; apr_status_t rv; free(ti); apr_pool_create(&ptrans, tpool); apr_lock_acquire(worker_thread_count_mutex); worker_thread_count++; apr_lock_release(worker_thread_count_mutex); apr_poll_setup(&pollset, num_listensocks+1, tpool); for(n = 0; n <= num_listensocks; ++n) apr_poll_socket_add(pollset, listensocks[n], APR_POLLIN); /* TODO: Switch to a system where threads reuse the results from earlier poll calls - manoj */ while (1) { if (requests_this_child <= 0) { check_infinite_requests(); } if (workers_may_exit) break; (void) ap_update_child_status(process_slot, thread_slot, SERVER_READY, (request_rec *) NULL); while (!workers_may_exit) { apr_status_t ret; apr_int16_t event; ret = apr_poll(pollset, &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)"); workers_may_exit = 1; } if (workers_may_exit) break; apr_poll_revents_get(&event, listensocks[0], pollset); if (event & APR_POLLIN) { /* A process got a signal on the shutdown pipe. Check if we're * the lucky process to die. */ check_pipe_of_death(); continue; } if (num_listensocks == 1) { sd = ap_listeners->sd; goto got_fd; } else { /* find a listener */ curr_pollfd = last_pollfd; do { curr_pollfd++; if (curr_pollfd > num_listensocks) { curr_pollfd = 1; } /* XXX: Should we check for POLLERR? */ apr_poll_revents_get(&event, listensocks[curr_pollfd], pollset); if (event & APR_POLLIN) { last_pollfd = curr_pollfd; sd=listensocks[curr_pollfd]; goto got_fd; } } while (curr_pollfd != last_pollfd); } } got_fd: if (!workers_may_exit) { rv = SAFE_ACCEPT(apr_lock_tryacquire(accept_mutex)); switch (rv) { case APR_SUCCESS: if ((rv = apr_accept(&csd, sd, ptrans)) != APR_SUCCESS) { csd = NULL; ap_log_error(APLOG_MARK, APLOG_ERR, rv, ap_server_conf, "apr_accept"); } if ((rv = SAFE_ACCEPT(apr_lock_release(accept_mutex))) != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, "apr_lock_release failed. Attempting to shutdown " "process gracefully."); workers_may_exit = 1; } if (csd != NULL) { process_socket(ptrans, csd, process_slot, thread_slot); requests_this_child--; } break; case APR_EBUSY: break; default: ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, "apr_lock_tryacquire failed. Attempting to shutdown " "process gracefully."); workers_may_exit = 1; break; } } apr_pool_clear(ptrans); } apr_pool_destroy(tpool); ap_update_child_status(process_slot, thread_slot, (dying) ? SERVER_DEAD : SERVER_GRACEFUL, (request_rec *) NULL); dying = 1; apr_lock_acquire(worker_thread_count_mutex); worker_thread_count--; if (worker_thread_count == 0) { /* All the threads have exited, now finish the shutdown process * by signalling the sigwait thread */ kill(ap_my_pid, SIGTERM); } apr_lock_release(worker_thread_count_mutex); return NULL; } static int check_signal(int signum) { switch (signum) { case SIGTERM: case SIGINT: return 1; } return 0; } /* This is called by the child process when we want to start the threads. */ static int start_threads() { apr_thread_t **threads; int i; ap_listen_rec *lr; apr_status_t rv; thread_starter *ts; apr_threadattr_t *thread_attr; proc_info *my_info; /* Startup the listeners specified in the config */ if ((num_listensocks = ap_setup_listeners(ap_server_conf)) < 1) { ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ALERT, 0, ap_server_conf, "no listening sockets available, shutting down"); return 1; } /* Initialize: accept, thread count, and POD intraprocess mutexes */ rv = apr_lock_create(&accept_mutex, APR_MUTEX, APR_INTRAPROCESS, NULL, pproc); if (rv != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, "Couldn't create accept lock"); return 1; } rv = apr_lock_create(&worker_thread_count_mutex, APR_MUTEX, APR_INTRAPROCESS, NULL, pproc); if (rv != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, "Couldn't create worker thread count"); return 1; } rv = apr_lock_create(&pipe_of_death_mutex, APR_MUTEX, APR_INTRAPROCESS, NULL, pproc); if (rv != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, "Couldn't create pipe of death lock"); return 1; } set_signals(); /* Don't allow invalid configurations to allow us to thrash. */ if (max_spare_threads < min_spare_threads + ap_threads_per_child) max_spare_threads = min_spare_threads + ap_threads_per_child; ap_my_pid = getpid(); if (unixd_setup_child()) { return APEXIT_CHILDFATAL; } ap_run_child_init(pproc, ap_server_conf); 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"); return 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; } /* Set up the pollfd array. * Note that the POD is treated as a "fake" listener. */ listensocks = apr_pcalloc(pproc, sizeof(*listensocks) * (num_listensocks + 1)); apr_socket_from_file(&listensocks[0], pipe_of_death_in); for (lr = ap_listeners, i = 1; i <= num_listensocks; lr = lr->next, ++i) listensocks[i]=lr->sd; /* Setup worker threads */ threads = (apr_thread_t **)malloc(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"); return APEXIT_CHILDFATAL; } worker_thread_count = 0; ts = apr_palloc(pproc, sizeof(*ts)); apr_threadattr_create(&thread_attr, pproc); /* 0 means PTHREAD_CREATE_JOINABLE */ apr_threadattr_detach_set(thread_attr, 0); ts->threads = threads; ts->child_num_arg = 0; ts->threadattr = thread_attr; for (i=0; i < ap_threads_per_child; i++) { int status = ap_scoreboard_image->servers[0][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"); return APEXIT_CHILDFATAL; } /* By definition, we only have one process. */ my_info->pid = 0; my_info->tid = i; my_info->sd = 0; apr_pool_create(&my_info->tpool, pproc); /* We are creating threads right now */ (void) ap_update_child_status(0, i, SERVER_STARTING, (request_rec *) NULL); /* We let each thread update it's own scoreboard entry. This is * done because it let's us deal with tid better. */ if ((rv = apr_thread_create(&threads[i], thread_attr, worker_thread, my_info, pproc))) { 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. */ sleep(10); return APEXIT_CHILDFATAL; } } apr_signal_thread(check_signal); workers_may_exit = 1; /* helps us terminate a little more quickly when * 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). */ for (i = 0; i < ap_threads_per_child; i++) { apr_thread_join(&rv, threads[i]); } free(threads); return 0; } static int make_child() { int child_status, child_pid; if (one_process) child_pid = 0; else child_pid = fork(); if (!child_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_NOERRNO|APLOG_WARNING, errno, ap_server_conf, "processor unbind failed %d", status); #endif /* Go spawn all the threads. */ child_status = start_threads(); clean_child_exit(child_status); } return child_pid; } /* If there aren't many connections coming in from the network, the child * processes may need to be awakened from their network i/o waits. * The pipe of death is an effective prod. */ static void wake_up_and_die(void) { int i; char char_of_death = '!'; apr_size_t one = 1; apr_status_t rv; if ((rv = apr_file_write(pipe_of_death_out, &char_of_death, &one)) != APR_SUCCESS) { if (APR_STATUS_IS_EINTR(rv)) continue; ap_log_error(APLOG_MARK, APLOG_WARNING, rv, ap_server_conf, "write pipe_of_death"); } } static void server_main_loop() { int child_slot; apr_wait_t status; apr_proc_t pid; int i; while (!restart_pending && !shutdown_pending) { ap_wait_or_timeout(&status, &pid, pconf); if (pid.pid != -1) { ap_process_child_status(&pid, status); /* non-fatal death... note that it's gone in the scoreboard. */ child_slot = 0; for (i = 0; i < ap_threads_per_child; i++) ap_update_child_status(child_slot, i, SERVER_DEAD, (request_rec *) NULL); make_child(); } } } int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) { pid_t child_pid; apr_status_t rv; pconf = _pconf; ap_server_conf = s; /* Create the POD before we fork. */ rv = apr_file_pipe_create(&pipe_of_death_in, &pipe_of_death_out, pconf); if (rv != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_ERR, rv, (const server_rec*) ap_server_conf, "apr_file_pipe_create (pipe_of_death)"); return 1; } if ((rv = apr_file_pipe_timeout_set(pipe_of_death_in, 0)) != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_ERR, rv, (const server_rec*) ap_server_conf, "apr_file_pipe_timeout_set (pipe_of_death)"); return 1; } ap_log_pid(pconf, ap_pid_fname); /* The scoreboard is visible from both the child and the parent. */ ap_run_pre_mpm(pconf, SB_SHARED); /* Create a per-process pool. */ apr_pool_create(&pproc, pconf); /* Go spawn the child. */ child_pid = make_child(); ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf, "%s configured -- resuming normal operations", ap_get_server_version()); ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0, ap_server_conf, "Server built: %s", ap_get_server_built()); restart_pending = shutdown_pending = 0; server_main_loop(); if (shutdown_pending) { /* Time to gracefully shut down: * Kill child processes, tell them to call child_exit, etc... */ wake_up_and_die(); if (unixd_killpg(getpgrp(), SIGTERM) < 0) { ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGTERM"); } ap_reclaim_child_processes(1); /* Start with SIGTERM */ /* cleanup pid file on normal shutdown */ { const char *pidfile = NULL; pidfile = ap_server_root_relative (pconf, ap_pid_fname); if (pidfile != NULL && unlink(pidfile) == 0) ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0, ap_server_conf, "removed PID file %s (pid=%ld)", pidfile, (long)getpid()); } ap_log_error(APLOG_MARK, APLOG_NOERRNO|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; update_scoreboard_global(); /* wake up the children...time to die. But we'll have more soon */ wake_up_and_die(); if (is_graceful) { ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf, "SIGWINCH received. Doing graceful restart"); /* 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. */ if (unixd_killpg(getpgrp(), SIGTERM) < 0) { ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGTERM"); } ap_reclaim_child_processes(1); /* Start with SIGTERM */ ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf, "SIGHUP received. Attempting to restart"); } return 0; } static void spmt_pre_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp) { static int restart_num = 0; int no_detach = 0; one_process = !!ap_exists_config_define("ONE_PROCESS"); no_detach = !!ap_exists_config_define("NO_DETACH"); /* sigh, want this only the second time around */ if (restart_num++ == 1) { is_graceful = 0; if (!one_process && !no_detach) { apr_proc_detach(); } 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 = HARD_SERVER_LIMIT; ap_threads_per_child = DEFAULT_THREADS_PER_CHILD; ap_pid_fname = DEFAULT_PIDLOG; ap_scoreboard_fname = DEFAULT_SCOREBOARD; lock_fname = DEFAULT_LOCKFILE; ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD; ap_extended_status = 0; apr_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir)); } static void spmt_hooks(apr_pool_t *p) { one_process = 0; ap_hook_pre_config(spmt_pre_config, NULL, NULL, APR_HOOK_MIDDLE); } static const char *set_pidfile(cmd_parms *cmd, void *dummy, const char *arg) { const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); if (err != NULL) { return err; } if (cmd->server->is_virtual) { return "PidFile directive not allowed in <VirtualHost>"; } ap_pid_fname = arg; return NULL; } static const char *set_scoreboard(cmd_parms *cmd, void *dummy, const char *arg) { const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); if (err != NULL) { return err; } ap_scoreboard_fname = arg; return NULL; } static const char *set_lockfile(cmd_parms *cmd, void *dummy, const char *arg) { const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); if (err != NULL) { return err; } lock_fname = arg; return NULL; } 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 | APLOG_NOERRNO, 0, NULL, "WARNING: detected MinSpareThreads set to non-positive."); ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, "Resetting to 1 to avoid almost certain Apache failure."); ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 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_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; } ap_daemons_limit = atoi(arg); if (ap_daemons_limit > HARD_SERVER_LIMIT) { ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, "WARNING: MaxClients of %d exceeds compile time limit " "of %d servers,", ap_daemons_limit, HARD_SERVER_LIMIT); ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, " lowering MaxClients to %d. To increase, please " "see the", HARD_SERVER_LIMIT); ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, " HARD_SERVER_LIMIT define in %s.", AP_MPM_HARD_LIMITS_FILE); ap_daemons_limit = HARD_SERVER_LIMIT; } else if (ap_daemons_limit < 1) { ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 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 > HARD_THREAD_LIMIT) { ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, "WARNING: ThreadsPerChild of %d exceeds compile time " "limit of %d threads,", ap_threads_per_child, HARD_THREAD_LIMIT); ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, " lowering ThreadsPerChild to %d. To increase, please" " see the", HARD_THREAD_LIMIT); ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, " HARD_THREAD_LIMIT define in %s.", AP_MPM_HARD_LIMITS_FILE); ap_threads_per_child = HARD_THREAD_LIMIT; } else if (ap_threads_per_child < 1) { ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, "WARNING: Require ThreadsPerChild > 0, setting to 1"); ap_threads_per_child = 1; } return NULL; } static const char *set_max_requests(cmd_parms *cmd, void *dummy, const char *arg) { const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); if (err != NULL) { return err; } ap_max_requests_per_child = atoi(arg); return NULL; } static const char *set_coredumpdir (cmd_parms *cmd, void *dummy, const char *arg) { apr_finfo_t finfo; const char *fname; const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); if (err != NULL) { return err; } fname = ap_server_root_relative(cmd->pool, arg); if ((apr_stat(&finfo, fname, APR_FINFO_TYPE, cmd->pool) != APR_SUCCESS) || (finfo.filetype != APR_DIR)) { return apr_pstrcat(cmd->pool, "CoreDumpDirectory ", fname, " does not exist or is not a directory", NULL); } apr_cpystrn(ap_coredump_dir, fname, sizeof(ap_coredump_dir)); return NULL; } static const char *set_accept_lock_mech(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(arg, "default")) { accept_lock_mech = APR_LOCK_DEFAULT; } #if APR_HAS_FLOCK_SERIALIZE else if (!strcasecmp(arg, "flock")) { accept_lock_mech = APR_LOCK_FLOCK; } #endif #if APR_HAS_FCNTL_SERIALIZE else if (!strcasecmp(arg, "fcntl")) { accept_lock_mech = APR_LOCK_FCNTL; } #endif #if APR_HAS_SYSVSEM_SERIALIZE else if (!strcasecmp(arg, "sysvsem")) { accept_lock_mech = APR_LOCK_SYSVSEM; } #endif #if APR_HAS_PROC_PTHREAD_SERIALIZE else if (!strcasecmp(arg, "proc_pthread")) { accept_lock_mech = APR_LOCK_PROC_PTHREAD; } #endif else { return apr_pstrcat(cmd->pool, arg, " is an invalid mutex mechanism; valid " "ones for this platform are: default" #if APR_HAS_FLOCK_SERIALIZE ", flock" #endif #if APR_HAS_FCNTL_SERIALIZE ", fcntl" #endif #if APR_HAS_SYSVSEM_SERIALIZE ", sysvsem" #endif #if APR_HAS_PROC_PTHREAD_SERIALIZE ", proc_pthread" #endif , NULL); } return NULL; } static const command_rec spmt_cmds[] = { UNIX_DAEMON_COMMANDS LISTEN_COMMANDS AP_INIT_TAKE1("PidFile", set_pidfile, NULL, RSRC_CONF, "A file for logging the server process ID"), AP_INIT_TAKE1("ScoreBoardFile", set_scoreboard, NULL, RSRC_CONF, "A file for Apache to maintain runtime process management information"), AP_INIT_TAKE1("LockFile", set_lockfile, NULL, RSRC_CONF, "The lockfile used when Apache needs to lock the accept() call"), 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_server_limit, 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("MaxRequestsPerChild", set_max_requests, NULL, RSRC_CONF, "Maximum number of requests a particular child serves before dying."), AP_INIT_TAKE1("CoreDumpDirectory", set_coredumpdir, NULL, RSRC_CONF, "The location of the directory Apache changes to before dumping core"), AP_INIT_TAKE1("AcceptMutex", set_accept_lock_mech, NULL, RSRC_CONF, "The system mutex implementation to use for the accept mutex"), { NULL } }; module AP_MODULE_DECLARE_DATA mpm_spmt_module = { 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 */ spmt_cmds, /* command apr_table_t */ spmt_hooks /* register_hooks */ };
