Mercurial > hg > nginx-quic
view src/event/modules/ngx_rtsig_module.c @ 4569:1db899642518
Upstream: reject upstreams without normal servers.
Such upstreams cause CPU hog later in the code as number of peers isn't
expected to be 0. Currently this may happen either if there are only backup
servers defined in an upstream block, or if server with ipv6 address used
in an upstream block.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 02 Apr 2012 21:29:35 +0000 |
parents | d620f497c50f |
children | 4c36e15651f7 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #if (NGX_TEST_BUILD_RTSIG) #ifdef SIGRTMIN #define si_fd _reason.__spare__.__spare2__[0] #else #define SIGRTMIN 33 #define si_fd __spare__[0] #endif #define F_SETSIG 10 #define KERN_RTSIGNR 30 #define KERN_RTSIGMAX 31 int sigtimedwait(const sigset_t *set, siginfo_t *info, const struct timespec *timeout) { return -1; } int ngx_linux_rtsig_max; #endif typedef struct { ngx_uint_t signo; ngx_uint_t overflow_events; ngx_uint_t overflow_test; ngx_uint_t overflow_threshold; } ngx_rtsig_conf_t; extern ngx_event_module_t ngx_poll_module_ctx; static ngx_int_t ngx_rtsig_init(ngx_cycle_t *cycle, ngx_msec_t timer); static void ngx_rtsig_done(ngx_cycle_t *cycle); static ngx_int_t ngx_rtsig_add_connection(ngx_connection_t *c); static ngx_int_t ngx_rtsig_del_connection(ngx_connection_t *c, ngx_uint_t flags); static ngx_int_t ngx_rtsig_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags); static ngx_int_t ngx_rtsig_process_overflow(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags); static void *ngx_rtsig_create_conf(ngx_cycle_t *cycle); static char *ngx_rtsig_init_conf(ngx_cycle_t *cycle, void *conf); static char *ngx_check_ngx_overflow_threshold_bounds(ngx_conf_t *cf, void *post, void *data); static sigset_t set; static ngx_uint_t overflow, overflow_current; static struct pollfd *overflow_list; static ngx_str_t rtsig_name = ngx_string("rtsig"); static ngx_conf_num_bounds_t ngx_overflow_threshold_bounds = { ngx_check_ngx_overflow_threshold_bounds, 2, 10 }; static ngx_command_t ngx_rtsig_commands[] = { { ngx_string("rtsig_signo"), NGX_EVENT_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, 0, offsetof(ngx_rtsig_conf_t, signo), NULL }, { ngx_string("rtsig_overflow_events"), NGX_EVENT_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, 0, offsetof(ngx_rtsig_conf_t, overflow_events), NULL }, { ngx_string("rtsig_overflow_test"), NGX_EVENT_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, 0, offsetof(ngx_rtsig_conf_t, overflow_test), NULL }, { ngx_string("rtsig_overflow_threshold"), NGX_EVENT_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, 0, offsetof(ngx_rtsig_conf_t, overflow_threshold), &ngx_overflow_threshold_bounds }, ngx_null_command }; ngx_event_module_t ngx_rtsig_module_ctx = { &rtsig_name, ngx_rtsig_create_conf, /* create configuration */ ngx_rtsig_init_conf, /* init configuration */ { NULL, /* add an event */ NULL, /* delete an event */ NULL, /* enable an event */ NULL, /* disable an event */ ngx_rtsig_add_connection, /* add an connection */ ngx_rtsig_del_connection, /* delete an connection */ NULL, /* process the changes */ ngx_rtsig_process_events, /* process the events */ ngx_rtsig_init, /* init the events */ ngx_rtsig_done, /* done the events */ } }; ngx_module_t ngx_rtsig_module = { NGX_MODULE_V1, &ngx_rtsig_module_ctx, /* module context */ ngx_rtsig_commands, /* module directives */ NGX_EVENT_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_rtsig_init(ngx_cycle_t *cycle, ngx_msec_t timer) { ngx_rtsig_conf_t *rtscf; rtscf = ngx_event_get_conf(cycle->conf_ctx, ngx_rtsig_module); sigemptyset(&set); sigaddset(&set, (int) rtscf->signo); sigaddset(&set, (int) rtscf->signo + 1); sigaddset(&set, SIGIO); sigaddset(&set, SIGALRM); if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) { ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno, "sigprocmask() failed"); return NGX_ERROR; } if (overflow_list) { ngx_free(overflow_list); } overflow_list = ngx_alloc(sizeof(struct pollfd) * rtscf->overflow_events, cycle->log); if (overflow_list == NULL) { return NGX_ERROR; } ngx_io = ngx_os_io; ngx_event_actions = ngx_rtsig_module_ctx.actions; ngx_event_flags = NGX_USE_RTSIG_EVENT |NGX_USE_GREEDY_EVENT |NGX_USE_FD_EVENT; return NGX_OK; } static void ngx_rtsig_done(ngx_cycle_t *cycle) { ngx_free(overflow_list); overflow_list = NULL; } static ngx_int_t ngx_rtsig_add_connection(ngx_connection_t *c) { ngx_uint_t signo; ngx_rtsig_conf_t *rtscf; if (c->read->accept && c->read->disabled) { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "rtsig enable connection: fd:%d", c->fd); if (fcntl(c->fd, F_SETOWN, ngx_pid) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno, "fcntl(F_SETOWN) failed"); return NGX_ERROR; } c->read->active = 1; c->read->disabled = 0; } rtscf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_rtsig_module); signo = rtscf->signo + c->read->instance; ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "rtsig add connection: fd:%d signo:%ui", c->fd, signo); if (fcntl(c->fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno, "fcntl(O_RDWR|O_NONBLOCK|O_ASYNC) failed"); return NGX_ERROR; } if (fcntl(c->fd, F_SETSIG, (int) signo) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno, "fcntl(F_SETSIG) failed"); return NGX_ERROR; } if (fcntl(c->fd, F_SETOWN, ngx_pid) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno, "fcntl(F_SETOWN) failed"); return NGX_ERROR; } #if (NGX_HAVE_ONESIGFD) if (fcntl(c->fd, F_SETAUXFL, O_ONESIGFD) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno, "fcntl(F_SETAUXFL) failed"); return NGX_ERROR; } #endif c->read->active = 1; c->write->active = 1; return NGX_OK; } static ngx_int_t ngx_rtsig_del_connection(ngx_connection_t *c, ngx_uint_t flags) { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "rtsig del connection: fd:%d", c->fd); if ((flags & NGX_DISABLE_EVENT) && c->read->accept) { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "rtsig disable connection: fd:%d", c->fd); c->read->active = 0; c->read->disabled = 1; return NGX_OK; } if (flags & NGX_CLOSE_EVENT) { c->read->active = 0; c->write->active = 0; return NGX_OK; } if (fcntl(c->fd, F_SETFL, O_RDWR|O_NONBLOCK) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno, "fcntl(O_RDWR|O_NONBLOCK) failed"); return NGX_ERROR; } c->read->active = 0; c->write->active = 0; return NGX_OK; } static ngx_int_t ngx_rtsig_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags) { int signo; ngx_int_t instance; ngx_err_t err; siginfo_t si; ngx_event_t *rev, *wev, **queue; struct timespec ts, *tp; struct sigaction sa; ngx_connection_t *c; ngx_rtsig_conf_t *rtscf; if (timer == NGX_TIMER_INFINITE) { tp = NULL; } else { ts.tv_sec = timer / 1000; ts.tv_nsec = (timer % 1000) * 1000000; tp = &ts; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "rtsig timer: %M", timer); /* Linux's sigwaitinfo() is sigtimedwait() with the NULL timeout pointer */ signo = sigtimedwait(&set, &si, tp); if (signo == -1) { err = ngx_errno; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, err, "rtsig signo:%d", signo); if (flags & NGX_UPDATE_TIME) { ngx_time_update(); } if (err == NGX_EAGAIN) { /* timeout */ if (timer != NGX_TIMER_INFINITE) { return NGX_AGAIN; } ngx_log_error(NGX_LOG_ALERT, cycle->log, err, "sigtimedwait() returned EAGAIN without timeout"); return NGX_ERROR; } ngx_log_error((err == NGX_EINTR) ? NGX_LOG_INFO : NGX_LOG_ALERT, cycle->log, err, "sigtimedwait() failed"); return NGX_ERROR; } ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "rtsig signo:%d fd:%d band:%04Xd", signo, si.si_fd, si.si_band); if (flags & NGX_UPDATE_TIME) { ngx_time_update(); } rtscf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_rtsig_module); if (signo == (int) rtscf->signo || signo == (int) rtscf->signo + 1) { if (overflow && (ngx_uint_t) si.si_fd > overflow_current) { return NGX_OK; } c = ngx_cycle->files[si.si_fd]; if (c == NULL) { /* the stale event */ return NGX_OK; } instance = signo - (int) rtscf->signo; rev = c->read; if (rev->instance != instance) { /* * the stale event from a file descriptor * that was just closed in this iteration */ ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "rtsig: stale event %p", c); return NGX_OK; } if ((si.si_band & (POLLIN|POLLHUP|POLLERR)) && rev->active) { rev->ready = 1; if (flags & NGX_POST_EVENTS) { queue = (ngx_event_t **) (rev->accept ? &ngx_posted_accept_events : &ngx_posted_events); ngx_locked_post_event(rev, queue); } else { rev->handler(rev); } } wev = c->write; if ((si.si_band & (POLLOUT|POLLHUP|POLLERR)) && wev->active) { wev->ready = 1; if (flags & NGX_POST_EVENTS) { ngx_locked_post_event(wev, &ngx_posted_events); } else { wev->handler(wev); } } return NGX_OK; } else if (signo == SIGALRM) { ngx_time_update(); return NGX_OK; } else if (signo == SIGIO) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "rt signal queue overflowed"); /* flush the RT signal queue */ ngx_memzero(&sa, sizeof(struct sigaction)); sa.sa_handler = SIG_DFL; sigemptyset(&sa.sa_mask); if (sigaction(rtscf->signo, &sa, NULL) == -1) { ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "sigaction(%d, SIG_DFL) failed", rtscf->signo); } if (sigaction(rtscf->signo + 1, &sa, NULL) == -1) { ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "sigaction(%d, SIG_DFL) failed", rtscf->signo + 1); } overflow = 1; overflow_current = 0; ngx_event_actions.process_events = ngx_rtsig_process_overflow; return NGX_ERROR; } ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "sigtimedwait() returned unexpected signal: %d", signo); return NGX_ERROR; } static ngx_int_t ngx_rtsig_process_overflow(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags) { int name[2], rtsig_max, rtsig_nr, events, ready; size_t len; ngx_err_t err; ngx_uint_t tested, n, i; ngx_event_t *rev, *wev, **queue; ngx_connection_t *c; ngx_rtsig_conf_t *rtscf; ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "rtsig process overflow"); rtscf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_rtsig_module); tested = 0; for ( ;; ) { n = 0; while (n < rtscf->overflow_events) { if (overflow_current == cycle->connection_n) { break; } c = cycle->files[overflow_current++]; if (c == NULL || c->fd == -1) { continue; } events = 0; if (c->read->active && c->read->handler) { events |= POLLIN; } if (c->write->active && c->write->handler) { events |= POLLOUT; } if (events == 0) { continue; } overflow_list[n].fd = c->fd; overflow_list[n].events = events; overflow_list[n].revents = 0; n++; } if (n == 0) { break; } for ( ;; ) { ready = poll(overflow_list, n, 0); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "rtsig overflow poll:%d", ready); if (ready == -1) { err = ngx_errno; ngx_log_error((err == NGX_EINTR) ? NGX_LOG_INFO : NGX_LOG_ALERT, cycle->log, 0, "poll() failed while the overflow recover"); if (err == NGX_EINTR) { continue; } } break; } if (ready <= 0) { continue; } ngx_mutex_lock(ngx_posted_events_mutex); for (i = 0; i < n; i++) { c = cycle->files[overflow_list[i].fd]; if (c == NULL) { continue; } rev = c->read; if (rev->active && !rev->closed && rev->handler && (overflow_list[i].revents & (POLLIN|POLLERR|POLLHUP|POLLNVAL))) { tested++; if ((flags & NGX_POST_THREAD_EVENTS) && !rev->accept) { rev->posted_ready = 1; } else { rev->ready = 1; } if (flags & NGX_POST_EVENTS) { queue = (ngx_event_t **) (rev->accept ? &ngx_posted_accept_events : &ngx_posted_events); ngx_locked_post_event(rev, queue); } else { rev->handler(rev); } } wev = c->write; if (wev->active && !wev->closed && wev->handler && (overflow_list[i].revents & (POLLOUT|POLLERR|POLLHUP|POLLNVAL))) { tested++; if (flags & NGX_POST_THREAD_EVENTS) { wev->posted_ready = 1; } else { wev->ready = 1; } if (flags & NGX_POST_EVENTS) { ngx_locked_post_event(wev, &ngx_posted_events); } else { wev->handler(wev); } } } ngx_mutex_unlock(ngx_posted_events_mutex); if (tested >= rtscf->overflow_test) { if (ngx_linux_rtsig_max) { /* * Check the current rt queue length to prevent * the new overflow. * * learn the "/proc/sys/kernel/rtsig-max" value because * it can be changed since the last checking */ name[0] = CTL_KERN; name[1] = KERN_RTSIGMAX; len = sizeof(rtsig_max); if (sysctl(name, 2, &rtsig_max, &len, NULL, 0) == -1) { ngx_log_error(NGX_LOG_ALERT, cycle->log, errno, "sysctl(KERN_RTSIGMAX) failed"); return NGX_ERROR; } /* name[0] = CTL_KERN; */ name[1] = KERN_RTSIGNR; len = sizeof(rtsig_nr); if (sysctl(name, 2, &rtsig_nr, &len, NULL, 0) == -1) { ngx_log_error(NGX_LOG_ALERT, cycle->log, errno, "sysctl(KERN_RTSIGNR) failed"); return NGX_ERROR; } /* * drain the rt signal queue if the /"proc/sys/kernel/rtsig-nr" * is bigger than * "/proc/sys/kernel/rtsig-max" / "rtsig_overflow_threshold" */ if (rtsig_max / (int) rtscf->overflow_threshold < rtsig_nr) { ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "rtsig queue state: %d/%d", rtsig_nr, rtsig_max); while (ngx_rtsig_process_events(cycle, 0, flags) == NGX_OK) { /* void */ } } } else { /* * Linux has not KERN_RTSIGMAX since 2.6.6-mm2 * so drain the rt signal queue unconditionally */ while (ngx_rtsig_process_events(cycle, 0, flags) == NGX_OK) { /* void */ } } tested = 0; } } if (flags & NGX_UPDATE_TIME) { ngx_time_update(); } ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "rt signal queue overflow recovered"); overflow = 0; ngx_event_actions.process_events = ngx_rtsig_process_events; return NGX_OK; } static void * ngx_rtsig_create_conf(ngx_cycle_t *cycle) { ngx_rtsig_conf_t *rtscf; rtscf = ngx_palloc(cycle->pool, sizeof(ngx_rtsig_conf_t)); if (rtscf == NULL) { return NULL; } rtscf->signo = NGX_CONF_UNSET; rtscf->overflow_events = NGX_CONF_UNSET; rtscf->overflow_test = NGX_CONF_UNSET; rtscf->overflow_threshold = NGX_CONF_UNSET; return rtscf; } static char * ngx_rtsig_init_conf(ngx_cycle_t *cycle, void *conf) { ngx_rtsig_conf_t *rtscf = conf; /* LinuxThreads use the first 3 RT signals */ ngx_conf_init_uint_value(rtscf->signo, SIGRTMIN + 10); ngx_conf_init_uint_value(rtscf->overflow_events, 16); ngx_conf_init_uint_value(rtscf->overflow_test, 32); ngx_conf_init_uint_value(rtscf->overflow_threshold, 10); return NGX_CONF_OK; } static char * ngx_check_ngx_overflow_threshold_bounds(ngx_conf_t *cf, void *post, void *data) { if (ngx_linux_rtsig_max) { return ngx_conf_check_num_bounds(cf, post, data); } ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "\"rtsig_overflow_threshold\" is not supported " "since Linux 2.6.6-mm2, ignored"); return NGX_CONF_OK; }