Mercurial > hg > nginx-quic
view src/event/ngx_event_accept.c @ 4311:45272aab5eea
Unlock of shared memory zones on process crash.
If process exited abnormally while holding lock on some shared memory zone -
unlock it. It may be not safe thing to do (as crash with lock held may
result in corrupted shared memory structure, and other processes will
subsequently crash while trying to access shared data), therefore complain
loudly if unlock succeeds.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 23 Nov 2011 14:09:19 +0000 |
parents | c870fb78550c |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> static ngx_int_t ngx_enable_accept_events(ngx_cycle_t *cycle); static ngx_int_t ngx_disable_accept_events(ngx_cycle_t *cycle); static void ngx_close_accepted_connection(ngx_connection_t *c); void ngx_event_accept(ngx_event_t *ev) { socklen_t socklen; ngx_err_t err; ngx_log_t *log; ngx_socket_t s; ngx_event_t *rev, *wev; ngx_listening_t *ls; ngx_connection_t *c, *lc; ngx_event_conf_t *ecf; u_char sa[NGX_SOCKADDRLEN]; #if (NGX_HAVE_ACCEPT4) static ngx_uint_t use_accept4 = 1; #endif ecf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_event_core_module); if (ngx_event_flags & NGX_USE_RTSIG_EVENT) { ev->available = 1; } else if (!(ngx_event_flags & NGX_USE_KQUEUE_EVENT)) { ev->available = ecf->multi_accept; } lc = ev->data; ls = lc->listening; ev->ready = 0; ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "accept on %V, ready: %d", &ls->addr_text, ev->available); do { socklen = NGX_SOCKADDRLEN; #if (NGX_HAVE_ACCEPT4) if (use_accept4) { s = accept4(lc->fd, (struct sockaddr *) sa, &socklen, SOCK_NONBLOCK); } else { s = accept(lc->fd, (struct sockaddr *) sa, &socklen); } #else s = accept(lc->fd, (struct sockaddr *) sa, &socklen); #endif if (s == -1) { err = ngx_socket_errno; if (err == NGX_EAGAIN) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err, "accept() not ready"); return; } #if (NGX_HAVE_ACCEPT4) ngx_log_error((ngx_uint_t) ((err == NGX_ECONNABORTED) ? NGX_LOG_ERR : NGX_LOG_ALERT), ev->log, err, use_accept4 ? "accept4() failed" : "accept() failed"); if (use_accept4 && err == NGX_ENOSYS) { use_accept4 = 0; ngx_inherited_nonblocking = 0; continue; } #else ngx_log_error((ngx_uint_t) ((err == NGX_ECONNABORTED) ? NGX_LOG_ERR : NGX_LOG_ALERT), ev->log, err, "accept() failed"); #endif if (err == NGX_ECONNABORTED) { if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ev->available--; } if (ev->available) { continue; } } return; } #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_accepted, 1); #endif ngx_accept_disabled = ngx_cycle->connection_n / 8 - ngx_cycle->free_connection_n; c = ngx_get_connection(s, ev->log); if (c == NULL) { if (ngx_close_socket(s) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_socket_errno, ngx_close_socket_n " failed"); } return; } #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, 1); #endif c->pool = ngx_create_pool(ls->pool_size, ev->log); if (c->pool == NULL) { ngx_close_accepted_connection(c); return; } c->sockaddr = ngx_palloc(c->pool, socklen); if (c->sockaddr == NULL) { ngx_close_accepted_connection(c); return; } ngx_memcpy(c->sockaddr, sa, socklen); log = ngx_palloc(c->pool, sizeof(ngx_log_t)); if (log == NULL) { ngx_close_accepted_connection(c); return; } /* set a blocking mode for aio and non-blocking mode for others */ if (ngx_inherited_nonblocking) { if (ngx_event_flags & NGX_USE_AIO_EVENT) { if (ngx_blocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_socket_errno, ngx_blocking_n " failed"); ngx_close_accepted_connection(c); return; } } } else { if (!(ngx_event_flags & (NGX_USE_AIO_EVENT|NGX_USE_RTSIG_EVENT))) { if (ngx_nonblocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_socket_errno, ngx_nonblocking_n " failed"); ngx_close_accepted_connection(c); return; } } } *log = ls->log; c->recv = ngx_recv; c->send = ngx_send; c->recv_chain = ngx_recv_chain; c->send_chain = ngx_send_chain; c->log = log; c->pool->log = log; c->socklen = socklen; c->listening = ls; c->local_sockaddr = ls->sockaddr; c->unexpected_eof = 1; #if (NGX_HAVE_UNIX_DOMAIN) if (c->sockaddr->sa_family == AF_UNIX) { c->tcp_nopush = NGX_TCP_NOPUSH_DISABLED; c->tcp_nodelay = NGX_TCP_NODELAY_DISABLED; #if (NGX_SOLARIS) /* Solaris's sendfilev() supports AF_NCA, AF_INET, and AF_INET6 */ c->sendfile = 0; #endif } #endif rev = c->read; wev = c->write; wev->ready = 1; if (ngx_event_flags & (NGX_USE_AIO_EVENT|NGX_USE_RTSIG_EVENT)) { /* rtsig, aio, iocp */ rev->ready = 1; } if (ev->deferred_accept) { rev->ready = 1; #if (NGX_HAVE_KQUEUE) rev->available = 1; #endif } rev->log = log; wev->log = log; /* * TODO: MT: - ngx_atomic_fetch_add() * or protection by critical section or light mutex * * TODO: MP: - allocated in a shared memory * - ngx_atomic_fetch_add() * or protection by critical section or light mutex */ c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_handled, 1); #endif #if (NGX_THREADS) rev->lock = &c->lock; wev->lock = &c->lock; rev->own_lock = &c->lock; wev->own_lock = &c->lock; #endif if (ls->addr_ntop) { c->addr_text.data = ngx_pnalloc(c->pool, ls->addr_text_max_len); if (c->addr_text.data == NULL) { ngx_close_accepted_connection(c); return; } c->addr_text.len = ngx_sock_ntop(c->sockaddr, c->addr_text.data, ls->addr_text_max_len, 0); if (c->addr_text.len == 0) { ngx_close_accepted_connection(c); return; } } #if (NGX_DEBUG) { in_addr_t i; ngx_event_debug_t *dc; struct sockaddr_in *sin; sin = (struct sockaddr_in *) sa; dc = ecf->debug_connection.elts; for (i = 0; i < ecf->debug_connection.nelts; i++) { if ((sin->sin_addr.s_addr & dc[i].mask) == dc[i].addr) { log->log_level = NGX_LOG_DEBUG_CONNECTION|NGX_LOG_DEBUG_ALL; break; } } } #endif ngx_log_debug3(NGX_LOG_DEBUG_EVENT, log, 0, "*%d accept: %V fd:%d", c->number, &c->addr_text, s); if (ngx_add_conn && (ngx_event_flags & NGX_USE_EPOLL_EVENT) == 0) { if (ngx_add_conn(c) == NGX_ERROR) { ngx_close_accepted_connection(c); return; } } log->data = NULL; log->handler = NULL; ls->handler(c); if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ev->available--; } } while (ev->available); } ngx_int_t ngx_trylock_accept_mutex(ngx_cycle_t *cycle) { if (ngx_shmtx_trylock(&ngx_accept_mutex)) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "accept mutex locked"); if (ngx_accept_mutex_held && ngx_accept_events == 0 && !(ngx_event_flags & NGX_USE_RTSIG_EVENT)) { return NGX_OK; } if (ngx_enable_accept_events(cycle) == NGX_ERROR) { ngx_shmtx_unlock(&ngx_accept_mutex); return NGX_ERROR; } ngx_accept_events = 0; ngx_accept_mutex_held = 1; return NGX_OK; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "accept mutex lock failed: %ui", ngx_accept_mutex_held); if (ngx_accept_mutex_held) { if (ngx_disable_accept_events(cycle) == NGX_ERROR) { return NGX_ERROR; } ngx_accept_mutex_held = 0; } return NGX_OK; } static ngx_int_t ngx_enable_accept_events(ngx_cycle_t *cycle) { ngx_uint_t i; ngx_listening_t *ls; ngx_connection_t *c; ls = cycle->listening.elts; for (i = 0; i < cycle->listening.nelts; i++) { c = ls[i].connection; if (ngx_event_flags & NGX_USE_RTSIG_EVENT) { if (ngx_add_conn(c) == NGX_ERROR) { return NGX_ERROR; } } else { if (ngx_add_event(c->read, NGX_READ_EVENT, 0) == NGX_ERROR) { return NGX_ERROR; } } } return NGX_OK; } static ngx_int_t ngx_disable_accept_events(ngx_cycle_t *cycle) { ngx_uint_t i; ngx_listening_t *ls; ngx_connection_t *c; ls = cycle->listening.elts; for (i = 0; i < cycle->listening.nelts; i++) { c = ls[i].connection; if (!c->read->active) { continue; } if (ngx_event_flags & NGX_USE_RTSIG_EVENT) { if (ngx_del_conn(c, NGX_DISABLE_EVENT) == NGX_ERROR) { return NGX_ERROR; } } else { if (ngx_del_event(c->read, NGX_READ_EVENT, NGX_DISABLE_EVENT) == NGX_ERROR) { return NGX_ERROR; } } } return NGX_OK; } static void ngx_close_accepted_connection(ngx_connection_t *c) { ngx_socket_t fd; ngx_free_connection(c); fd = c->fd; c->fd = (ngx_socket_t) -1; if (ngx_close_socket(fd) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_socket_errno, ngx_close_socket_n " failed"); } if (c->pool) { ngx_destroy_pool(c->pool); } #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, -1); #endif } u_char * ngx_accept_log_error(ngx_log_t *log, u_char *buf, size_t len) { return ngx_snprintf(buf, len, " while accepting new connection on %V", log->data); }