Mercurial > hg > nginx
view src/event/modules/ngx_devpoll_module.c @ 7446:9234e8d61aa0
Win32: detection of connect() errors in select().
On Windows, connect() errors are only reported via exceptfds descriptor set
from select(). Previously exceptfds was set to NULL, and connect() errors
were not detected at all, so connects to closed ports were waiting till
a timeout occurred.
Since ongoing connect() means that there will be a write event active,
except descriptor set is copied from the write one. While it is possible
to construct except descriptor set as a concatenation of both read and write
descriptor sets, this looks unneeded.
With this change, connect() errors are properly detected now when using
select(). Note well that it is not possible to detect connect() errors with
WSAPoll() (see https://daniel.haxx.se/blog/2012/10/10/wsapoll-is-broken/).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 24 Jan 2019 22:00:44 +0300 |
parents | fbdaad9b0e7b |
children | efd71d49bde0 |
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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_DEVPOLL) /* Solaris declarations */ #ifndef POLLREMOVE #define POLLREMOVE 0x0800 #endif #define DP_POLL 0xD001 #define DP_ISPOLLED 0xD002 struct dvpoll { struct pollfd *dp_fds; int dp_nfds; int dp_timeout; }; #endif typedef struct { ngx_uint_t changes; ngx_uint_t events; } ngx_devpoll_conf_t; static ngx_int_t ngx_devpoll_init(ngx_cycle_t *cycle, ngx_msec_t timer); static void ngx_devpoll_done(ngx_cycle_t *cycle); static ngx_int_t ngx_devpoll_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags); static ngx_int_t ngx_devpoll_del_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags); static ngx_int_t ngx_devpoll_set_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags); static ngx_int_t ngx_devpoll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags); static void *ngx_devpoll_create_conf(ngx_cycle_t *cycle); static char *ngx_devpoll_init_conf(ngx_cycle_t *cycle, void *conf); static int dp = -1; static struct pollfd *change_list, *event_list; static ngx_uint_t nchanges, max_changes, nevents; static ngx_event_t **change_index; static ngx_str_t devpoll_name = ngx_string("/dev/poll"); static ngx_command_t ngx_devpoll_commands[] = { { ngx_string("devpoll_changes"), NGX_EVENT_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, 0, offsetof(ngx_devpoll_conf_t, changes), NULL }, { ngx_string("devpoll_events"), NGX_EVENT_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, 0, offsetof(ngx_devpoll_conf_t, events), NULL }, ngx_null_command }; static ngx_event_module_t ngx_devpoll_module_ctx = { &devpoll_name, ngx_devpoll_create_conf, /* create configuration */ ngx_devpoll_init_conf, /* init configuration */ { ngx_devpoll_add_event, /* add an event */ ngx_devpoll_del_event, /* delete an event */ ngx_devpoll_add_event, /* enable an event */ ngx_devpoll_del_event, /* disable an event */ NULL, /* add an connection */ NULL, /* delete an connection */ NULL, /* trigger a notify */ ngx_devpoll_process_events, /* process the events */ ngx_devpoll_init, /* init the events */ ngx_devpoll_done, /* done the events */ } }; ngx_module_t ngx_devpoll_module = { NGX_MODULE_V1, &ngx_devpoll_module_ctx, /* module context */ ngx_devpoll_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_devpoll_init(ngx_cycle_t *cycle, ngx_msec_t timer) { size_t n; ngx_devpoll_conf_t *dpcf; dpcf = ngx_event_get_conf(cycle->conf_ctx, ngx_devpoll_module); if (dp == -1) { dp = open("/dev/poll", O_RDWR); if (dp == -1) { ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno, "open(/dev/poll) failed"); return NGX_ERROR; } } if (max_changes < dpcf->changes) { if (nchanges) { n = nchanges * sizeof(struct pollfd); if (write(dp, change_list, n) != (ssize_t) n) { ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "write(/dev/poll) failed"); return NGX_ERROR; } nchanges = 0; } if (change_list) { ngx_free(change_list); } change_list = ngx_alloc(sizeof(struct pollfd) * dpcf->changes, cycle->log); if (change_list == NULL) { return NGX_ERROR; } if (change_index) { ngx_free(change_index); } change_index = ngx_alloc(sizeof(ngx_event_t *) * dpcf->changes, cycle->log); if (change_index == NULL) { return NGX_ERROR; } } max_changes = dpcf->changes; if (nevents < dpcf->events) { if (event_list) { ngx_free(event_list); } event_list = ngx_alloc(sizeof(struct pollfd) * dpcf->events, cycle->log); if (event_list == NULL) { return NGX_ERROR; } } nevents = dpcf->events; ngx_io = ngx_os_io; ngx_event_actions = ngx_devpoll_module_ctx.actions; ngx_event_flags = NGX_USE_LEVEL_EVENT|NGX_USE_FD_EVENT; return NGX_OK; } static void ngx_devpoll_done(ngx_cycle_t *cycle) { if (close(dp) == -1) { ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "close(/dev/poll) failed"); } dp = -1; ngx_free(change_list); ngx_free(event_list); ngx_free(change_index); change_list = NULL; event_list = NULL; change_index = NULL; max_changes = 0; nchanges = 0; nevents = 0; } static ngx_int_t ngx_devpoll_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags) { #if (NGX_DEBUG) ngx_connection_t *c; #endif #if (NGX_READ_EVENT != POLLIN) event = (event == NGX_READ_EVENT) ? POLLIN : POLLOUT; #endif #if (NGX_DEBUG) c = ev->data; ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "devpoll add event: fd:%d ev:%04Xi", c->fd, event); #endif ev->active = 1; return ngx_devpoll_set_event(ev, event, 0); } static ngx_int_t ngx_devpoll_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; #if (NGX_READ_EVENT != POLLIN) event = (event == NGX_READ_EVENT) ? POLLIN : POLLOUT; #endif ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "devpoll del event: fd:%d ev:%04Xi", c->fd, event); if (ngx_devpoll_set_event(ev, POLLREMOVE, flags) == NGX_ERROR) { return NGX_ERROR; } ev->active = 0; if (flags & NGX_CLOSE_EVENT) { e = (event == POLLIN) ? c->write : c->read; if (e) { e->active = 0; } return NGX_OK; } /* restore the pair event if it exists */ if (event == POLLIN) { e = c->write; event = POLLOUT; } else { e = c->read; event = POLLIN; } if (e && e->active) { return ngx_devpoll_set_event(e, event, 0); } return NGX_OK; } static ngx_int_t ngx_devpoll_set_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags) { size_t n; ngx_connection_t *c; c = ev->data; ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0, "devpoll fd:%d ev:%04Xi fl:%04Xi", c->fd, event, flags); if (nchanges >= max_changes) { ngx_log_error(NGX_LOG_WARN, ev->log, 0, "/dev/pool change list is filled up"); n = nchanges * sizeof(struct pollfd); if (write(dp, change_list, n) != (ssize_t) n) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno, "write(/dev/poll) failed"); return NGX_ERROR; } nchanges = 0; } change_list[nchanges].fd = c->fd; change_list[nchanges].events = (short) event; change_list[nchanges].revents = 0; change_index[nchanges] = ev; ev->index = nchanges; nchanges++; if (flags & NGX_CLOSE_EVENT) { n = nchanges * sizeof(struct pollfd); if (write(dp, change_list, n) != (ssize_t) n) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno, "write(/dev/poll) failed"); return NGX_ERROR; } nchanges = 0; } return NGX_OK; } static ngx_int_t ngx_devpoll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags) { int events, revents, rc; size_t n; ngx_fd_t fd; ngx_err_t err; ngx_int_t i; ngx_uint_t level, instance; ngx_event_t *rev, *wev; ngx_queue_t *queue; ngx_connection_t *c; struct pollfd pfd; struct dvpoll dvp; /* NGX_TIMER_INFINITE == INFTIM */ ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "devpoll timer: %M", timer); if (nchanges) { n = nchanges * sizeof(struct pollfd); if (write(dp, change_list, n) != (ssize_t) n) { ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "write(/dev/poll) failed"); return NGX_ERROR; } nchanges = 0; } dvp.dp_fds = event_list; dvp.dp_nfds = (int) nevents; dvp.dp_timeout = timer; events = ioctl(dp, DP_POLL, &dvp); err = (events == -1) ? ngx_errno : 0; if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) { ngx_time_update(); } 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, "ioctl(DP_POLL) failed"); return NGX_ERROR; } if (events == 0) { if (timer != NGX_TIMER_INFINITE) { return NGX_OK; } ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "ioctl(DP_POLL) returned no events without timeout"); return NGX_ERROR; } for (i = 0; i < events; i++) { fd = event_list[i].fd; revents = event_list[i].revents; c = ngx_cycle->files[fd]; if (c == NULL || c->fd == -1) { pfd.fd = fd; pfd.events = 0; pfd.revents = 0; rc = ioctl(dp, DP_ISPOLLED, &pfd); switch (rc) { case -1: ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "ioctl(DP_ISPOLLED) failed for socket %d, event %04Xd", fd, revents); break; case 0: ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "phantom event %04Xd for closed and removed socket %d", revents, fd); break; default: ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "unexpected event %04Xd for closed and removed socket %d, " "ioctl(DP_ISPOLLED) returned rc:%d, fd:%d, event %04Xd", revents, fd, rc, pfd.fd, pfd.revents); pfd.fd = fd; pfd.events = POLLREMOVE; pfd.revents = 0; if (write(dp, &pfd, sizeof(struct pollfd)) != (ssize_t) sizeof(struct pollfd)) { ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "write(/dev/poll) for %d failed", fd); } if (close(fd) == -1) { ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "close(%d) failed", fd); } break; } continue; } ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "devpoll: fd:%d, ev:%04Xd, rev:%04Xd", fd, event_list[i].events, revents); if (revents & (POLLERR|POLLHUP|POLLNVAL)) { ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "ioctl(DP_POLL) error fd:%d ev:%04Xd rev:%04Xd", fd, event_list[i].events, revents); } if (revents & ~(POLLIN|POLLOUT|POLLERR|POLLHUP|POLLNVAL)) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "strange ioctl(DP_POLL) events " "fd:%d ev:%04Xd rev:%04Xd", fd, event_list[i].events, revents); } if (revents & (POLLERR|POLLHUP|POLLNVAL)) { /* * if the error events were returned, add POLLIN and POLLOUT * to handle the events at least in one active handler */ revents |= POLLIN|POLLOUT; } rev = c->read; if ((revents & POLLIN) && rev->active) { rev->ready = 1; if (flags & NGX_POST_EVENTS) { queue = rev->accept ? &ngx_posted_accept_events : &ngx_posted_events; ngx_post_event(rev, queue); } else { instance = rev->instance; rev->handler(rev); if (c->fd == -1 || rev->instance != instance) { continue; } } } wev = c->write; if ((revents & POLLOUT) && wev->active) { wev->ready = 1; if (flags & NGX_POST_EVENTS) { ngx_post_event(wev, &ngx_posted_events); } else { wev->handler(wev); } } } return NGX_OK; } static void * ngx_devpoll_create_conf(ngx_cycle_t *cycle) { ngx_devpoll_conf_t *dpcf; dpcf = ngx_palloc(cycle->pool, sizeof(ngx_devpoll_conf_t)); if (dpcf == NULL) { return NULL; } dpcf->changes = NGX_CONF_UNSET; dpcf->events = NGX_CONF_UNSET; return dpcf; } static char * ngx_devpoll_init_conf(ngx_cycle_t *cycle, void *conf) { ngx_devpoll_conf_t *dpcf = conf; ngx_conf_init_uint_value(dpcf->changes, 32); ngx_conf_init_uint_value(dpcf->events, 32); return NGX_CONF_OK; }