/* ==================================================================== * The Apache Software License, Version 1.1 * * Copyright (c) 2000 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. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowledgment may appear in the software itself, * if and wherever such third-party acknowledgments normally appear. * * 4. The names "Apache" and "Apache Software Foundation" must * not be used to endorse or promote products derived from this * software without prior written permission. For written * permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache", * nor may "Apache" appear in their name, without prior written * permission of the Apache Software Foundation. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. 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 * . * * Portions of this software are based upon public domain software * originally written at the National Center for Supercomputing Applications, * University of Illinois, Urbana-Champaign. */ #define CORE_PRIVATE #include "apr_portable.h" #include "apr_file_io.h" #include "apr_thread_proc.h" #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 "iol_socket.h" #include "ap_listen.h" #include "scoreboard.h" #ifdef HAVE_NETINET_TCP_H #include #endif #include #include #include /* * Actual definitions of config globals */ int ap_threads_per_child=0; /* Worker threads per child */ int ap_max_requests_per_child=0; static char *ap_pid_fname=NULL; API_VAR_EXPORT char *ap_scoreboard_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 time_t ap_restart_time=0; API_VAR_EXPORT int ap_extended_status = 0; static int workers_may_exit = 0; static int requests_this_child; static int num_listensocks = 0; static ap_socket_t **listensocks; /* The structure used to pass unique initialization info to each thread */ typedef struct { int pid; int tid; int sd; ap_pool_t *tpool; /* "pthread" would be confusing */ } proc_info; /* * 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; static char ap_coredump_dir[MAX_STRING_LEN]; int pipe_of_death[2]; static pthread_mutex_t pipe_of_death_mutex; /* *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 ap_pool_t *pconf; /* Pool for config stuff */ static ap_pool_t *pchild; /* Pool for httpd child stuff */ int 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 pthread_mutex_t worker_thread_count_mutex; /* Locks for accept serialization */ static pthread_mutex_t thread_accept_mutex = PTHREAD_MUTEX_INITIALIZER; static ap_lock_t *process_accept_mutex; static char *lock_fname; #ifdef NO_SERIALIZED_ACCEPT #define SAFE_ACCEPT(stmt) APR_SUCCESS #else #define SAFE_ACCEPT(stmt) (stmt) #endif API_EXPORT(const server_rec *) ap_get_server_conf(void) { return (ap_server_conf); } API_EXPORT(int) ap_get_max_daemons(void) { return ap_max_daemons_limit; } /* a clean exit from a child with proper cleanup */ static void clean_child_exit(int code) __attribute__ ((noreturn)); void clean_child_exit(int code) { if (pchild) { ap_destroy_pool(pchild); } exit(code); } /* handle all varieties of core dumping signals */ static void sig_coredump(int sig) { chdir(ap_coredump_dir); ap_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. */ 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 */ 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; } static void sig_term(int sig) { ap_start_shutdown(); } static void restart(int sig) { #ifndef WIN32 ap_start_restart(sig == SIGWINCH); #else ap_start_restart(1); #endif } 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) { ap_signal(SIGSEGV, sig_coredump); #ifdef SIGBUS ap_signal(SIGBUS, sig_coredump); #endif /* SIGBUS */ #ifdef SIGABORT ap_signal(SIGABORT, sig_coredump); #endif /* SIGABORT */ #ifdef SIGABRT ap_signal(SIGABRT, sig_coredump); #endif /* SIGABRT */ #ifdef SIGILL ap_signal(SIGILL, sig_coredump); #endif /* SIGILL */ #ifdef SIGXCPU ap_signal(SIGXCPU, SIG_DFL); #endif /* SIGXCPU */ #ifdef SIGXFSZ ap_signal(SIGXFSZ, SIG_DFL); #endif /* SIGXFSZ */ } ap_signal(SIGTERM, sig_term); #ifdef SIGHUP ap_signal(SIGHUP, restart); #endif /* SIGHUP */ #ifdef SIGWINCH ap_signal(SIGWINCH, restart); #endif /* SIGWINCH */ #ifdef SIGPIPE ap_signal(SIGPIPE, SIG_IGN); #endif /* SIGPIPE */ #endif } static void process_child_status(ap_proc_t *pid, ap_wait_t status) { /* Child died... if it died due to a fatal error, * we should simply bail out. */ if ((WIFEXITED(status)) && WEXITSTATUS(status) == APEXIT_CHILDFATAL) { ap_log_error(APLOG_MARK, APLOG_ALERT|APLOG_NOERRNO, 0, ap_server_conf, "Child %ld returned a Fatal error... \n" "Apache is exiting!", (long)pid->pid); exit(APEXIT_CHILDFATAL); } if (WIFSIGNALED(status)) { switch (WTERMSIG(status)) { case SIGTERM: case SIGHUP: case SIGUSR1: case SIGKILL: break; default: #ifdef SYS_SIGLIST #ifdef WCOREDUMP if (WCOREDUMP(status)) { ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf, "child pid %ld exit signal %s (%d), " "possible coredump in %s", (long)pid->pid, (WTERMSIG(status) >= NumSIG) ? "" : SYS_SIGLIST[WTERMSIG(status)], WTERMSIG(status), ap_coredump_dir); } else { #endif ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf, "child pid %ld exit signal %s (%d)", (long)pid->pid, SYS_SIGLIST[WTERMSIG(status)], WTERMSIG(status)); #ifdef WCOREDUMP } #endif #else ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, ap_server_conf, "child pid %ld exit signal %d", (long)pid->pid, WTERMSIG(status)); #endif } } } static int setup_listeners(server_rec *s) { ap_listen_rec *lr; int num_listeners = 0; if (ap_listen_open(s->process, s->port)) { return 0; } for (lr = ap_listeners; lr; lr = lr->next) { num_listeners++; } return num_listeners; } /***************************************************************** * Here follows a long bunch of generic server bookkeeping stuff... */ #if defined(TCP_NODELAY) && !defined(MPE) && !defined(TPF) static void sock_disable_nagle(int s) { /* The Nagle algorithm says that we should delay sending partial * packets in hopes of getting more data. We don't want to do * this; we are not telnet. There are bad interactions between * persistent connections and Nagle's algorithm that have very severe * performance penalties. (Failing to disable Nagle is not much of a * problem with simple HTTP.) * * In spite of these problems, failure here is not a shooting offense. */ int just_say_no = 1; if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (char *) &just_say_no, sizeof(int)) < 0) { ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "setsockopt: (TCP_NODELAY)"); } } #else #define sock_disable_nagle(s) /* NOOP */ #endif int ap_graceful_stop_signalled(void) { /* XXX - Does this really work? - Manoj */ return is_graceful; } /***************************************************************** * Child process main loop. */ static void process_socket(ap_pool_t *p, ap_socket_t *sock, int my_child_num, int my_thread_num) { BUFF *conn_io; conn_rec *current_conn; ap_iol *iol; long conn_id = my_child_num * HARD_THREAD_LIMIT + my_thread_num; int csd; (void) ap_get_os_sock(&csd, sock); sock_disable_nagle(csd); iol = unix_attach_socket(sock); if (iol == NULL) { if (errno == EBADF) { ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, 0, NULL, "filedescriptor (%u) larger than FD_SETSIZE (%u) " "found, you probably need to rebuild Apache with a " "larger FD_SETSIZE", csd, FD_SETSIZE); } else { ap_log_error(APLOG_MARK, APLOG_WARNING, errno, NULL, "error attaching to socket"); } ap_close_socket(sock); return; } (void) ap_update_child_status(my_child_num, my_thread_num, SERVER_BUSY_READ, (request_rec *) NULL); conn_io = ap_bcreate(p, B_RDWR); ap_bpush_iol(conn_io, iol); current_conn = ap_new_apr_connection(p, ap_server_conf, conn_io, sock, conn_id); ap_process_connection(current_conn); ap_lingering_close(current_conn); } /* Sets workers_may_exit if we received a character on the pipe_of_death */ static void check_pipe_of_death(void) { pthread_mutex_lock(&pipe_of_death_mutex); if (!workers_may_exit) { ap_status_t ret; char pipe_read_char; int n=1; ret = ap_recv(listensocks[0], &pipe_read_char, &n); if (ap_canonical_error(ret) == APR_EAGAIN) { /* 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. */ workers_may_exit = 1; } } pthread_mutex_unlock(&pipe_of_death_mutex); } static void * worker_thread(void * dummy) { proc_info * ti = dummy; int process_slot = ti->pid; int thread_slot = ti->tid; ap_pool_t *tpool = ti->tpool; ap_socket_t *csd = NULL; ap_pool_t *ptrans; /* Pool for per-transaction stuff */ ap_socket_t *sd = NULL; int n; int curr_pollfd, last_pollfd = 0; ap_pollfd_t *pollset; ap_status_t rv; free(ti); ap_create_pool(&ptrans, tpool); pthread_mutex_lock(&worker_thread_count_mutex); worker_thread_count++; pthread_mutex_unlock(&worker_thread_count_mutex); ap_setup_poll(&pollset, num_listensocks+1, tpool); for(n=0 ; n <= num_listensocks ; ++n) ap_add_poll_socket(pollset, listensocks[n], APR_POLLIN); /* TODO: Switch to a system where threads reuse the results from earlier poll calls - manoj */ while (!workers_may_exit) { workers_may_exit |= (ap_max_requests_per_child != 0) && (requests_this_child <= 0); if (workers_may_exit) break; (void) ap_update_child_status(process_slot, thread_slot, SERVER_READY, (request_rec *) NULL); pthread_mutex_lock(&thread_accept_mutex); if (workers_may_exit) { pthread_mutex_unlock(&thread_accept_mutex); break; } if ((rv = SAFE_ACCEPT(ap_lock(process_accept_mutex))) != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, "ap_lock failed. Attempting to shutdown " "process gracefully."); workers_may_exit = 1; } while (!workers_may_exit) { ap_status_t ret; ap_int16_t event; ret = ap_poll(pollset, &n, -1); if (ret != APR_SUCCESS) { if (ret == APR_EINTR) { continue; } /* poll() will only return errors in catastrophic * circumstances. Let's try exiting gracefully, for now. */ ap_log_error(APLOG_MARK, APLOG_ERR, errno, (const server_rec *) ap_get_server_conf(), "poll: (listen)"); workers_may_exit = 1; } if (workers_may_exit) break; ap_get_revents(&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? */ ap_get_revents(&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) { ap_accept(&csd, sd, ptrans); if ((rv = SAFE_ACCEPT(ap_unlock(process_accept_mutex))) != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, "ap_unlock failed. Attempting to shutdown " "process gracefully."); workers_may_exit = 1; } pthread_mutex_unlock(&thread_accept_mutex); process_socket(ptrans, csd, process_slot, thread_slot); requests_this_child--; } else { if ((rv = SAFE_ACCEPT(ap_unlock(process_accept_mutex))) != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, "ap_unlock failed. Attempting to shutdown " "process gracefully."); workers_may_exit = 1; } pthread_mutex_unlock(&thread_accept_mutex); break; } ap_clear_pool(ptrans); } ap_destroy_pool(tpool); ap_update_child_status(process_slot, thread_slot, SERVER_DEAD, (request_rec *) NULL); pthread_mutex_lock(&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); } pthread_mutex_unlock(&worker_thread_count_mutex); return NULL; } static void child_main(int child_num_arg) { sigset_t sig_mask; int signal_received; pthread_t thread; pthread_attr_t thread_attr; int i; int my_child_num = child_num_arg; proc_info *my_info = NULL; ap_listen_rec *lr; ap_status_t rv; ap_my_pid = getpid(); ap_create_pool(&pchild, pconf); /*stuff to do before we switch id's, so we have permissions.*/ reopen_scoreboard(pchild); rv = SAFE_ACCEPT(ap_child_init_lock(&process_accept_mutex, 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_child_init_hook(pchild, ap_server_conf); /*done with init critical section */ /* All threads should mask signals out, accoring to sigwait(2) man page */ sigfillset(&sig_mask); #ifdef SIGPROCMASK_SETS_THREAD_MASK if (sigprocmask(SIG_SETMASK, &sig_mask, NULL) != 0) { ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf, "sigprocmask"); } #else if (pthread_sigmask(SIG_SETMASK, &sig_mask, NULL) != 0) { ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf, "pthread_sigmask"); } #endif requests_this_child = ap_max_requests_per_child; /* Set up the pollfd array */ listensocks = ap_palloc(pchild, sizeof(*listensocks) * (num_listensocks + 1)); ap_create_tcp_socket(&listensocks[0], pchild); ap_put_os_sock(&listensocks[0], &pipe_of_death[0], pchild); for (lr = ap_listeners, i = 1; i <= num_listensocks; lr = lr->next, ++i) listensocks[i]=lr->sd; /* Setup worker threads */ worker_thread_count = 0; pthread_mutex_init(&worker_thread_count_mutex, NULL); pthread_mutex_init(&pipe_of_death_mutex, NULL); pthread_attr_init(&thread_attr); #ifdef PTHREAD_ATTR_SETDETACHSTATE_ARG2_ADDR { int on = 1; pthread_attr_setdetachstate(&thread_attr, &on); } #else pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); #endif for (i=0; i < ap_threads_per_child; i++) { 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; ap_create_pool(&my_info->tpool, pchild); /* We are creating threads right now */ (void) ap_update_child_status(my_child_num, i, SERVER_STARTING, (request_rec *) NULL); #ifndef NO_THREADS if (pthread_create(&thread, &thread_attr, worker_thread, my_info)) { ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf, "pthread_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); clean_child_exit(APEXIT_CHILDFATAL); } #else worker_thread(my_info); /* The SIGTERM shouldn't let us reach this point, but just in case... */ clean_child_exit(APEXIT_OK); #endif /* We let each thread update it's own scoreboard entry. This is done * because it let's us deal with tid better. */ } pthread_attr_destroy(&thread_attr); /* This thread will be the one responsible for handling signals */ sigemptyset(&sig_mask); sigaddset(&sig_mask, SIGTERM); sigaddset(&sig_mask, SIGINT); ap_sigwait(&sig_mask, &signal_received); switch (signal_received) { case SIGTERM: case SIGINT: just_die(signal_received); break; default: ap_log_error(APLOG_MARK, APLOG_ALERT, errno, ap_server_conf, "received impossible signal: %d", signal_received); just_die(SIGTERM); } } static int make_child(server_rec *s, int slot, time_t now) { 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); } /* Tag this slot as occupied so that perform_idle_server_maintenance * doesn't try to steal it */ (void) ap_update_child_status(slot, 0, SERVER_STARTING, (request_rec *) NULL); 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 */ (void) ap_update_child_status(slot, 0, SERVER_DEAD, (request_rec *) NULL); /* In case system resources are maxxed out, we don't want Apache running away with the CPU trying to fork over and over and over again. */ sleep(10); return -1; } if (!pid) { #ifdef AIX_BIND_PROCESSOR /* By default, AIX binds to a single processor. This bit unbinds children which will then bind to another CPU. */ #include int status = bindprocessor(BINDPROCESS, (int)getpid(), PROCESSOR_CLASS_ANY); if (status != OK) ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, ap_server_conf, "processor unbind failed %d", status); #endif RAISE_SIGSTOP(MAKE_CHILD); ap_signal(SIGTERM, just_die); child_main(slot); return 0; } /* else */ 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) < 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; thread_score *ss; time_t now = 0; int free_length; int free_slots[MAX_SPAWN_RATE]; int last_non_dead; int total_non_dead; /* initialize the free_list */ free_length = 0; idle_thread_count = 0; last_non_dead = -1; total_non_dead = 0; ap_sync_scoreboard_image(); 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 all_dead_threads = 1; int idle_thread_addition = 0; if (i >= ap_max_daemons_limit && free_length == idle_spawn_rate) break; for (j = 0; j < ap_threads_per_child; j++) { ss = &ap_scoreboard_image->servers[i][j]; status = ss->status; any_dying_threads = any_dying_threads || (status == SERVER_DEAD) || (status == SERVER_GRACEFUL); all_dead_threads = all_dead_threads && (status == SERVER_DEAD); /* We consider a starting server as idle because we started it * at least a cycle ago, and if it still hasn't finished starting * then we're just going to swamp things worse by forking more. * So we hopefully won't need to fork more if we count it. * This depends on the ordering of SERVER_READY and SERVER_STARTING. */ if (status <= SERVER_READY) { ++idle_thread_addition; } } if (all_dead_threads && free_length < idle_spawn_rate) { free_slots[free_length] = i; ++free_length; } if (!all_dead_threads) { last_non_dead = i; } if (!any_dying_threads) { ++total_non_dead; idle_thread_count += idle_thread_addition; } } ap_max_daemons_limit = last_non_dead + 1; if (idle_thread_count > max_spare_threads) { /* Kill off one child */ char char_of_death = '!'; if (write(pipe_of_death[1], &char_of_death, 1) == -1) { ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "write pipe_of_death"); } 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_NOERRNO|APLOG_ERR, 0, ap_server_conf, "server reached MaxClients setting, consider" " raising the MaxClients setting"); reported = 1; } idle_spawn_rate = 1; } else { if (idle_spawn_rate >= 8) { ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0, ap_server_conf, "server seems busy, (you may need " "to increase StartServers, ThreadsPerChild " "or Min/MaxSparetThreads), " "spawning %d children, there are around %d idle " "threads, and %d total children", idle_spawn_rate, idle_thread_count, total_non_dead); } for (i = 0; i < free_length; ++i) { make_child(ap_server_conf, free_slots[i], now); } /* 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; ap_wait_t status; ap_proc_t pid; int i; while (!restart_pending && !shutdown_pending) { ap_wait_or_timeout(&status, &pid, pconf); if (pid.pid != -1) { process_child_status(&pid, status); /* non-fatal death... note that it's gone in the scoreboard. */ child_slot = find_child_by_pid(&pid); if (child_slot >= 0) { ap_mpmt_pthread_force_reset_connection_status(child_slot); for (i = 0; i < ap_threads_per_child; i++) ap_update_child_status(child_slot, i, SERVER_DEAD, (request_rec *) NULL); 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, time(NULL)); --remaining_children_to_start; } #ifdef APR_HAS_OTHER_CHILD } else if (ap_reap_other_child(&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_NOERRNO|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(ap_pool_t *_pconf, ap_pool_t *plog, server_rec *s) { int remaining_children_to_start; ap_status_t rv; pconf = _pconf; ap_server_conf = s; if (pipe(pipe_of_death) == -1) { ap_log_error(APLOG_MARK, APLOG_ERR, errno, (const server_rec*) ap_server_conf, "pipe: (pipe_of_death)"); exit(1); } if (fcntl(pipe_of_death[0], F_SETFL, O_NONBLOCK) == -1) { ap_log_error(APLOG_MARK, APLOG_ERR, errno, (const server_rec*) ap_server_conf, "fcntl: O_NONBLOCKing (pipe_of_death)"); exit(1); } ap_server_conf = s; if ((num_listensocks = setup_listeners(ap_server_conf)) < 1) { /* XXX: hey, what's the right way for the mpm to indicate a fatal error? */ ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ALERT, 0, s, "no listening sockets available, shutting down"); return 1; } ap_log_pid(pconf, ap_pid_fname); /* Initialize cross-process accept lock */ lock_fname = ap_psprintf(_pconf, "%s.%lu", ap_server_root_relative(_pconf, lock_fname), ap_my_pid); rv = ap_create_lock(&process_accept_mutex, APR_MUTEX, APR_CROSS_PROCESS, lock_fname, _pconf); if (rv != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s, "Couldn't create cross-process lock"); return 1; } if (!is_graceful) { reinit_scoreboard(pconf); } 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 SIGWINCH). 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_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(remaining_children_to_start); if (shutdown_pending) { /* Time to gracefully shut down: * Kill child processes, tell them to call child_exit, etc... */ if (unixd_killpg(getpgrp(), SIGTERM) < 0) { ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGTERM"); } ap_reclaim_child_processes(1); /* Start with SIGTERM */ /* cleanup pid file on normal shutdown */ { const char *pidfile = NULL; pidfile = ap_server_root_relative (pconf, ap_pid_fname); if ( pidfile != NULL && unlink(pidfile) == 0) ap_log_error(APLOG_MARK, APLOG_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 */ ap_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(); if (is_graceful) { int i, j; char char_of_death = '!'; ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf, "SIGWINCH received. Doing graceful restart"); /* give the children the signal to die */ for (i = 0; i < ap_daemons_limit;) { if (write(pipe_of_death[1], &char_of_death, 1) == -1) { if (errno == EINTR) continue; ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "write pipe_of_death"); } i++; } /* This is mostly for debugging... so that we know what is still * gracefully dealing with existing request. */ for (i = 0; i < ap_daemons_limit; ++i) { for (j = 0; j < ap_threads_per_child; j++) { if (ap_scoreboard_image->servers[i][j].status != SERVER_DEAD) { ap_scoreboard_image->servers[i][j].status = SERVER_GRACEFUL; } } } } 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"); } if (!is_graceful) { ap_restart_time = time(NULL); } return 0; } static void mpmt_pthread_pre_config(ap_pool_t *pconf, ap_pool_t *plog, ap_pool_t *ptemp) { static int restart_num = 0; one_process = !!getenv("ONE_PROCESS"); /* sigh, want this only the second time around */ if (restart_num++ == 1) { is_graceful = 0; if (!one_process) { unixd_detach(); } ap_my_pid = getpid(); } unixd_pre_config(); 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; ap_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir)); } static void mpmt_pthread_hooks(void) { INIT_SIGLIST() one_process = 0; ap_hook_pre_config(mpmt_pthread_pre_config, NULL, NULL, AP_HOOK_MIDDLE); } static const char *set_pidfile(cmd_parms *cmd, void *dummy, 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 "; } ap_pid_fname = arg; return NULL; } static const char *set_scoreboard(cmd_parms *cmd, void *dummy, 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, 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, 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, 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, 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, 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 src/include/httpd.h."); 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\n"); ap_daemons_limit = 1; } return NULL; } static const char *set_threads_per_child (cmd_parms *cmd, void *dummy, 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 src/include/httpd.h."); } 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, 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, char *arg) { ap_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 ((ap_stat(&finfo, fname, cmd->pool) != APR_SUCCESS) || (finfo.filetype != APR_DIR)) { return ap_pstrcat(cmd->pool, "CoreDumpDirectory ", fname, " does not exist or is not a directory", NULL); } ap_cpystrn(ap_coredump_dir, fname, sizeof(ap_coredump_dir)); return NULL; } static const command_rec mpmt_pthread_cmds[] = { UNIX_DAEMON_COMMANDS LISTEN_COMMANDS { "PidFile", set_pidfile, NULL, RSRC_CONF, TAKE1, "A file for logging the server process ID"}, { "ScoreBoardFile", set_scoreboard, NULL, RSRC_CONF, TAKE1, "A file for Apache to maintain runtime process management information"}, { "LockFile", set_lockfile, NULL, RSRC_CONF, TAKE1, "The lockfile used when Apache needs to lock the accept() call"}, { "StartServers", set_daemons_to_start, NULL, RSRC_CONF, TAKE1, "Number of child processes launched at server startup" }, { "MinSpareThreads", set_min_spare_threads, NULL, RSRC_CONF, TAKE1, "Minimum number of idle children, to handle request spikes" }, { "MaxSpareThreads", set_max_spare_threads, NULL, RSRC_CONF, TAKE1, "Maximum number of idle children" }, { "MaxClients", set_server_limit, NULL, RSRC_CONF, TAKE1, "Maximum number of children alive at the same time" }, { "ThreadsPerChild", set_threads_per_child, NULL, RSRC_CONF, TAKE1, "Number of threads each child creates" }, { "MaxRequestsPerChild", set_max_requests, NULL, RSRC_CONF, TAKE1, "Maximum number of requests a particular child serves before dying." }, { "CoreDumpDirectory", set_coredumpdir, NULL, RSRC_CONF, TAKE1, "The location of the directory Apache changes to before dumping core" }, { NULL } }; module MODULE_VAR_EXPORT mpm_mpmt_pthread_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 */ mpmt_pthread_cmds, /* command ap_table_t */ NULL, /* handlers */ mpmt_pthread_hooks /* register_hooks */ };