view src/event/ngx_event_connect.c @ 3755:76e3a93821b1

fix race condition if during reconfiguration two cache managers try to delete old inactive entries: one of them removes a entry just locked by other manager from the queue and the rbtree as long inactive entry, causes the latter manager to segfault leaving cache mutex locked, the bug has been introduced in r3727
author Igor Sysoev <igor@sysoev.ru>
date Thu, 02 Sep 2010 14:31:47 +0000
parents d518c65ff0d4
children d620f497c50f
line wrap: on
line source


/*
 * 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;

    c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1);

#if (NGX_THREADS)

    /* TODO: lock event when call completion handler */

    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;
}