From 97659630cc36a1e76483cf022bcd1dc18a78e779 Mon Sep 17 00:00:00 2001 From: Jeff Trawick Date: Wed, 27 Mar 2002 20:37:32 +0000 Subject: [PATCH] worker MPM: get MaxRequestsPerChild to work again by allowing the main thread of a child to be interrupted by one of the other threads in the process this should get graceful termination to work after encountering one of the various possible error conditions in the listener and worker threads git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@94232 13f79535-47bb-0310-9956-ffa450edef68 --- CHANGES | 2 ++ server/mpm/worker/pod.c | 27 +++++++++------- server/mpm/worker/worker.c | 65 +++++++++++++++++++++++--------------- 3 files changed, 56 insertions(+), 38 deletions(-) diff --git a/CHANGES b/CHANGES index bf0231b824..500692fd7f 100644 --- a/CHANGES +++ b/CHANGES @@ -1,5 +1,7 @@ Changes with Apache 2.0.35 + *) worker MPM: Get MaxRequestsPerChild to work again. [Jeff Trawick] + *) [APR-related] The ordering of the default accept mutex method has been changed to better match what's done in Apache 1.3. The ordering is now (highest to lowest): pthread -> sysvsem -> fcntl -> flock. diff --git a/server/mpm/worker/pod.c b/server/mpm/worker/pod.c index 4a00145aa3..03ad947ada 100644 --- a/server/mpm/worker/pod.c +++ b/server/mpm/worker/pod.c @@ -72,6 +72,9 @@ #include "ap_mpm.h" #include "ap_listen.h" #include "mpm_default.h" +#if APR_HAVE_UNISTD_H +#include +#endif AP_DECLARE(apr_status_t) ap_mpm_pod_open(apr_pool_t *p, ap_pod_t **pod) { @@ -93,22 +96,22 @@ AP_DECLARE(apr_status_t) ap_mpm_pod_open(apr_pool_t *p, ap_pod_t **pod) AP_DECLARE(int) ap_mpm_pod_check(ap_pod_t *pod) { char c; - apr_size_t len = 1; - apr_status_t rv; - - rv = apr_file_read(pod->pod_in, &c, &len); - - if ((rv == APR_SUCCESS) && (len ==1)) { - if (c == RESTART_CHAR) { + apr_os_file_t fd; + int rc; + + /* we need to surface EINTR so we'll have to grab the + * native file descriptor and do the OS read() ourselves + */ + apr_os_file_get(&fd, pod->pod_in); + rc = read(fd, &c, 1); + if (rc == 1) { + switch(c) { + case RESTART_CHAR: return AP_RESTART; - } - if (c == GRACEFUL_CHAR) { + case GRACEFUL_CHAR: return AP_GRACEFUL; } } - else if (rv != APR_SUCCESS) { - return rv; - } return AP_NORESTART; } diff --git a/server/mpm/worker/worker.c b/server/mpm/worker/worker.c index dbc1ae8ec9..474a1e2964 100644 --- a/server/mpm/worker/worker.c +++ b/server/mpm/worker/worker.c @@ -262,17 +262,18 @@ static void wakeup_listener(void) pthread_kill(*listener_os_thread, LISTENER_SIGNAL); } +#define ST_INIT 0 #define ST_GRACEFUL 1 #define ST_UNGRACEFUL 2 +static int terminate_mode = ST_INIT; + static void signal_threads(int mode) { - static int prev_mode = 0; - - if (prev_mode == mode) { + if (terminate_mode == mode) { return; } - prev_mode = mode; + terminate_mode = mode; /* in case we weren't called from the listener thread, wake up the * listener thread @@ -625,7 +626,20 @@ static void check_infinite_requests(void) } } -static void unblock_the_listener(int sig) +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. @@ -645,8 +659,6 @@ static void *listener_thread(apr_thread_t *thd, void * dummy) apr_pollfd_t *pollset; apr_status_t rv; ap_listen_rec *lr, *last_lr = ap_listeners; - struct sigaction sa; - sigset_t sig_mask; free(ti); @@ -654,20 +666,11 @@ static void *listener_thread(apr_thread_t *thd, void * dummy) for(lr = ap_listeners ; lr != NULL ; lr = lr->next) apr_poll_socket_add(pollset, lr->sd, APR_POLLIN); - sigemptyset(&sig_mask); /* Unblock the signal used to wake this thread up, and set a handler for * it. */ - sigaddset(&sig_mask, LISTENER_SIGNAL); -#if defined(SIGPROCMASK_SETS_THREAD_MASK) - sigprocmask(SIG_UNBLOCK, &sig_mask, NULL); -#else - pthread_sigmask(SIG_UNBLOCK, &sig_mask, NULL); -#endif - sigemptyset(&sa.sa_mask); - sa.sa_flags = 0; - sa.sa_handler = unblock_the_listener; - sigaction(LISTENER_SIGNAL, &sa, NULL); + 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 */ @@ -811,10 +814,7 @@ static void *listener_thread(apr_thread_t *thd, void * dummy) dying = 1; ap_scoreboard_image->parent[process_slot].quiescing = 1; - /* XXX in one-process mode, this SIGTERM will wake up the main thread - * in normal mode, it is unclear what it will do... the main - * thread is stuck in a read on the POD - */ + /* wake up the main thread */ kill(ap_my_pid, SIGTERM); apr_thread_exit(thd, APR_SUCCESS); @@ -1196,13 +1196,26 @@ static void child_main(int child_num_arg) 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) { - /* XXX join_start_thread() won't be awakened if one of our - * threads encounters a critical error and attempts to - * shutdown this child - */ 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 -- 2.40.0