Mercurial > hg > nginx
view src/event/ngx_event_connect.c @ 3293:8abb88374c6c
Fix a bug introduced in r2032: After a child process has read a terminate
message from a channel, the process tries to read the channel again.
The kernel (at least FreeBSD) may preempt the process and sends a SIGIO
signal to a master process. The master process sends a new terminate message,
the kernel switches again to the the child process, and the child process
reads the messages instead of an EAGAIN error. And this may repeat over
and over. Being that the child process can not exit the cycle and test
the termination flag set by the message handler.
The fix disallow the master process to send a new terminate message on
SIGIO signal reception. It may send the message only on SIGALARM signal.
author | Igor Sysoev <igor@sysoev.ru> |
---|---|
date | Wed, 04 Nov 2009 19:41:08 +0000 |
parents | fcd98af88df3 |
children | d518c65ff0d4 |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_event_connect.h> ngx_int_t ngx_event_connect_peer(ngx_peer_connection_t *pc) { int rc; ngx_int_t event; ngx_err_t err; ngx_uint_t level; ngx_socket_t s; ngx_event_t *rev, *wev; ngx_connection_t *c; rc = pc->get(pc, pc->data); if (rc != NGX_OK) { return rc; } s = ngx_socket(pc->sockaddr->sa_family, SOCK_STREAM, 0); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, pc->log, 0, "socket %d", s); if (s == -1) { ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno, ngx_socket_n " failed"); return NGX_ERROR; } c = ngx_get_connection(s, pc->log); if (c == NULL) { if (ngx_close_socket(s) == -1) { ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno, ngx_close_socket_n "failed"); } return NGX_ERROR; } if (pc->rcvbuf) { if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, (const void *) &pc->rcvbuf, sizeof(int)) == -1) { ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno, "setsockopt(SO_RCVBUF) failed"); goto failed; } } if (ngx_nonblocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno, ngx_nonblocking_n " failed"); goto failed; } if (pc->local) { if (bind(s, pc->local->sockaddr, pc->local->socklen) == -1) { ngx_log_error(NGX_LOG_CRIT, pc->log, ngx_socket_errno, "bind(%V) failed", &pc->local->name); goto failed; } } c->recv = ngx_recv; c->send = ngx_send; c->recv_chain = ngx_recv_chain; c->send_chain = ngx_send_chain; c->sendfile = 1; c->log_error = pc->log_error; if (pc->sockaddr->sa_family != AF_INET) { 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 } rev = c->read; wev = c->write; rev->log = pc->log; wev->log = pc->log; pc->connection = c; /* * TODO: MT: - ngx_atomic_fetch_add() * or protection by critical section or mutex * * TODO: MP: - allocated in a shared memory * - ngx_atomic_fetch_add() * or protection by critical section or mutex */ c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); #if (NGX_THREADS) rev->lock = pc->lock; wev->lock = pc->lock; rev->own_lock = &c->lock; wev->own_lock = &c->lock; #endif if (ngx_add_conn) { if (ngx_add_conn(c) == NGX_ERROR) { goto failed; } } ngx_log_debug3(NGX_LOG_DEBUG_EVENT, pc->log, 0, "connect to %V, fd:%d #%d", pc->name, s, c->number); rc = connect(s, pc->sockaddr, pc->socklen); if (rc == -1) { err = ngx_socket_errno; if (err != NGX_EINPROGRESS #if (NGX_WIN32) /* Winsock returns WSAEWOULDBLOCK (NGX_EAGAIN) */ && err != NGX_EAGAIN #endif ) { if (err == NGX_ECONNREFUSED #if (NGX_LINUX) /* * Linux returns EAGAIN instead of ECONNREFUSED * for unix sockets if listen queue is full */ || err == NGX_EAGAIN #endif || err == NGX_ECONNRESET || err == NGX_ENETDOWN || err == NGX_ENETUNREACH || err == NGX_EHOSTDOWN || err == NGX_EHOSTUNREACH) { level = NGX_LOG_ERR; } else { level = NGX_LOG_CRIT; } ngx_log_error(level, c->log, err, "connect() to %V failed", pc->name); return NGX_DECLINED; } } if (ngx_add_conn) { if (rc == -1) { /* NGX_EINPROGRESS */ return NGX_AGAIN; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, pc->log, 0, "connected"); wev->ready = 1; return NGX_OK; } if (ngx_event_flags & NGX_USE_AIO_EVENT) { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, pc->log, ngx_socket_errno, "connect(): %d", rc); /* aio, iocp */ if (ngx_blocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno, ngx_blocking_n " failed"); goto failed; } /* * FreeBSD's aio allows to post an operation on non-connected socket. * NT does not support it. * * TODO: check in Win32, etc. As workaround we can use NGX_ONESHOT_EVENT */ rev->ready = 1; wev->ready = 1; return NGX_OK; } if (ngx_event_flags & NGX_USE_CLEAR_EVENT) { /* kqueue */ event = NGX_CLEAR_EVENT; } else { /* select, poll, /dev/poll */ event = NGX_LEVEL_EVENT; } if (ngx_add_event(rev, NGX_READ_EVENT, event) != NGX_OK) { goto failed; } if (rc == -1) { /* NGX_EINPROGRESS */ if (ngx_add_event(wev, NGX_WRITE_EVENT, event) != NGX_OK) { goto failed; } return NGX_AGAIN; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, pc->log, 0, "connected"); wev->ready = 1; return NGX_OK; failed: ngx_free_connection(c); if (ngx_close_socket(s) == -1) { ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno, ngx_close_socket_n " failed"); } return NGX_ERROR; } ngx_int_t ngx_event_get_peer(ngx_peer_connection_t *pc, void *data) { return NGX_OK; }