Mercurial > hg > nginx-quic
view src/event/modules/ngx_poll_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 | 4406168861e8 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> static ngx_int_t ngx_poll_init(ngx_cycle_t *cycle, ngx_msec_t timer); static void ngx_poll_done(ngx_cycle_t *cycle); static ngx_int_t ngx_poll_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags); static ngx_int_t ngx_poll_del_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags); static ngx_int_t ngx_poll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags); static char *ngx_poll_init_conf(ngx_cycle_t *cycle, void *conf); static struct pollfd *event_list; static ngx_int_t nevents; static ngx_str_t poll_name = ngx_string("poll"); ngx_event_module_t ngx_poll_module_ctx = { &poll_name, NULL, /* create configuration */ ngx_poll_init_conf, /* init configuration */ { ngx_poll_add_event, /* add an event */ ngx_poll_del_event, /* delete an event */ ngx_poll_add_event, /* enable an event */ ngx_poll_del_event, /* disable an event */ NULL, /* add an connection */ NULL, /* delete an connection */ NULL, /* process the changes */ ngx_poll_process_events, /* process the events */ ngx_poll_init, /* init the events */ ngx_poll_done /* done the events */ } }; ngx_module_t ngx_poll_module = { NGX_MODULE_V1, &ngx_poll_module_ctx, /* module context */ NULL, /* 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_poll_init(ngx_cycle_t *cycle, ngx_msec_t timer) { struct pollfd *list; if (event_list == NULL) { nevents = 0; } if (ngx_process >= NGX_PROCESS_WORKER || cycle->old_cycle == NULL || cycle->old_cycle->connection_n < cycle->connection_n) { list = ngx_alloc(sizeof(struct pollfd) * cycle->connection_n, cycle->log); if (list == NULL) { return NGX_ERROR; } if (event_list) { ngx_memcpy(list, event_list, sizeof(ngx_event_t *) * nevents); ngx_free(event_list); } event_list = list; } ngx_io = ngx_os_io; ngx_event_actions = ngx_poll_module_ctx.actions; ngx_event_flags = NGX_USE_LEVEL_EVENT|NGX_USE_FD_EVENT; return NGX_OK; } static void ngx_poll_done(ngx_cycle_t *cycle) { ngx_free(event_list); event_list = NULL; } static ngx_int_t ngx_poll_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags) { ngx_event_t *e; ngx_connection_t *c; c = ev->data; ev->active = 1; if (ev->index != NGX_INVALID_INDEX) { ngx_log_error(NGX_LOG_ALERT, ev->log, 0, "poll event fd:%d ev:%i is already set", c->fd, event); return NGX_OK; } if (event == NGX_READ_EVENT) { e = c->write; #if (NGX_READ_EVENT != POLLIN) event = POLLIN; #endif } else { e = c->read; #if (NGX_WRITE_EVENT != POLLOUT) event = POLLOUT; #endif } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "poll add event: fd:%d ev:%i", c->fd, event); if (e == NULL || e->index == NGX_INVALID_INDEX) { event_list[nevents].fd = c->fd; event_list[nevents].events = (short) event; event_list[nevents].revents = 0; ev->index = nevents; nevents++; } else { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ev->log, 0, "poll add index: %i", e->index); event_list[e->index].events |= (short) event; ev->index = e->index; } return NGX_OK; } static ngx_int_t ngx_poll_del_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags) { ngx_event_t *e; ngx_connection_t *c; c = ev->data; ev->active = 0; if (ev->index == NGX_INVALID_INDEX) { ngx_log_error(NGX_LOG_ALERT, ev->log, 0, "poll event fd:%d ev:%i is already deleted", c->fd, event); return NGX_OK; } if (event == NGX_READ_EVENT) { e = c->write; #if (NGX_READ_EVENT != POLLIN) event = POLLIN; #endif } else { e = c->read; #if (NGX_WRITE_EVENT != POLLOUT) event = POLLOUT; #endif } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "poll del event: fd:%d ev:%i", c->fd, event); if (e == NULL || e->index == NGX_INVALID_INDEX) { nevents--; if (ev->index < (ngx_uint_t) nevents) { ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "index: copy event %ui to %i", nevents, ev->index); event_list[ev->index] = event_list[nevents]; c = ngx_cycle->files[event_list[nevents].fd]; if (c->fd == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, 0, "unexpected last event"); } else { if (c->read->index == (ngx_uint_t) nevents) { c->read->index = ev->index; } if (c->write->index == (ngx_uint_t) nevents) { c->write->index = ev->index; } } } } else { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ev->log, 0, "poll del index: %i", e->index); event_list[e->index].events &= (short) ~event; } ev->index = NGX_INVALID_INDEX; return NGX_OK; } static ngx_int_t ngx_poll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags) { int ready, revents; ngx_err_t err; ngx_int_t i, nready; ngx_uint_t found, level; ngx_event_t *ev, **queue; ngx_connection_t *c; /* NGX_TIMER_INFINITE == INFTIM */ #if (NGX_DEBUG0) if (cycle->log->log_level & NGX_LOG_DEBUG_ALL) { for (i = 0; i < nevents; i++) { ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "poll: %d: fd:%d ev:%04Xd", i, event_list[i].fd, event_list[i].events); } } #endif ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "poll timer: %M", timer); ready = poll(event_list, (u_int) nevents, (int) timer); err = (ready == -1) ? ngx_errno : 0; if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) { ngx_time_update(); } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "poll ready %d of %d", ready, nevents); if (err) { if (err == NGX_EINTR) { if (ngx_event_timer_alarm) { ngx_event_timer_alarm = 0; return NGX_OK; } level = NGX_LOG_INFO; } else { level = NGX_LOG_ALERT; } ngx_log_error(level, cycle->log, err, "poll() failed"); return NGX_ERROR; } if (ready == 0) { if (timer != NGX_TIMER_INFINITE) { return NGX_OK; } ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "poll() returned no events without timeout"); return NGX_ERROR; } ngx_mutex_lock(ngx_posted_events_mutex); nready = 0; for (i = 0; i < nevents && ready; i++) { revents = event_list[i].revents; #if 1 ngx_log_debug4(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "poll: %d: fd:%d ev:%04Xd rev:%04Xd", i, event_list[i].fd, event_list[i].events, revents); #else if (revents) { ngx_log_debug4(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "poll: %d: fd:%d ev:%04Xd rev:%04Xd", i, event_list[i].fd, event_list[i].events, revents); } #endif if (revents & POLLNVAL) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "poll() error fd:%d ev:%04Xd rev:%04Xd", event_list[i].fd, event_list[i].events, revents); } if (revents & ~(POLLIN|POLLOUT|POLLERR|POLLHUP|POLLNVAL)) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "strange poll() events fd:%d ev:%04Xd rev:%04Xd", event_list[i].fd, event_list[i].events, revents); } if (event_list[i].fd == -1) { /* * the disabled event, a workaround for our possible bug, * see the comment below */ continue; } c = ngx_cycle->files[event_list[i].fd]; if (c->fd == -1) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "unexpected event"); /* * it is certainly our fault and it should be investigated, * in the meantime we disable this event to avoid a CPU spinning */ if (i == nevents - 1) { nevents--; } else { event_list[i].fd = -1; } continue; } if ((revents & (POLLERR|POLLHUP|POLLNVAL)) && (revents & (POLLIN|POLLOUT)) == 0) { /* * if the error events were returned without POLLIN or POLLOUT, * then add these flags to handle the events at least in one * active handler */ revents |= POLLIN|POLLOUT; } found = 0; if (revents & POLLIN) { found = 1; ev = c->read; if ((flags & NGX_POST_THREAD_EVENTS) && !ev->accept) { ev->posted_ready = 1; } else { ev->ready = 1; } queue = (ngx_event_t **) (ev->accept ? &ngx_posted_accept_events: &ngx_posted_events); ngx_locked_post_event(ev, queue); } if (revents & POLLOUT) { found = 1; ev = c->write; if (flags & NGX_POST_THREAD_EVENTS) { ev->posted_ready = 1; } else { ev->ready = 1; } ngx_locked_post_event(ev, &ngx_posted_events); } if (found) { ready--; continue; } } ngx_mutex_unlock(ngx_posted_events_mutex); if (ready != 0) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "poll ready != events"); } return nready; } static char * ngx_poll_init_conf(ngx_cycle_t *cycle, void *conf) { ngx_event_conf_t *ecf; ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module); if (ecf->use != ngx_poll_module.ctx_index) { return NGX_CONF_OK; } #if (NGX_THREADS) ngx_log_error(NGX_LOG_EMERG, cycle->log, 0, "poll() is not supported in the threaded mode"); return NGX_CONF_ERROR; #else return NGX_CONF_OK; #endif }