Mercurial > hg > nginx
view src/os/unix/ngx_channel.c @ 6339:67422a0a8ed2 stable-1.8
Events: made a failure to create a notification channel non-fatal.
This may happen if eventfd() returns ENOSYS, notably seen on CentOS 5.4.
Such a failure will now just disable the notification mechanism and let
the callers cope with it, instead of failing to start worker processes.
If thread pools are not configured, this can safely be ignored.
author | Ruslan Ermilov <ru@nginx.com> |
---|---|
date | Wed, 06 May 2015 17:04:00 +0300 |
parents | 3377f9459e99 |
children |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_channel.h> ngx_int_t ngx_write_channel(ngx_socket_t s, ngx_channel_t *ch, size_t size, ngx_log_t *log) { ssize_t n; ngx_err_t err; struct iovec iov[1]; struct msghdr msg; #if (NGX_HAVE_MSGHDR_MSG_CONTROL) union { struct cmsghdr cm; char space[CMSG_SPACE(sizeof(int))]; } cmsg; if (ch->fd == -1) { msg.msg_control = NULL; msg.msg_controllen = 0; } else { msg.msg_control = (caddr_t) &cmsg; msg.msg_controllen = sizeof(cmsg); ngx_memzero(&cmsg, sizeof(cmsg)); cmsg.cm.cmsg_len = CMSG_LEN(sizeof(int)); cmsg.cm.cmsg_level = SOL_SOCKET; cmsg.cm.cmsg_type = SCM_RIGHTS; /* * We have to use ngx_memcpy() instead of simple * *(int *) CMSG_DATA(&cmsg.cm) = ch->fd; * because some gcc 4.4 with -O2/3/s optimization issues the warning: * dereferencing type-punned pointer will break strict-aliasing rules * * Fortunately, gcc with -O1 compiles this ngx_memcpy() * in the same simple assignment as in the code above */ ngx_memcpy(CMSG_DATA(&cmsg.cm), &ch->fd, sizeof(int)); } msg.msg_flags = 0; #else if (ch->fd == -1) { msg.msg_accrights = NULL; msg.msg_accrightslen = 0; } else { msg.msg_accrights = (caddr_t) &ch->fd; msg.msg_accrightslen = sizeof(int); } #endif iov[0].iov_base = (char *) ch; iov[0].iov_len = size; msg.msg_name = NULL; msg.msg_namelen = 0; msg.msg_iov = iov; msg.msg_iovlen = 1; n = sendmsg(s, &msg, 0); if (n == -1) { err = ngx_errno; if (err == NGX_EAGAIN) { return NGX_AGAIN; } ngx_log_error(NGX_LOG_ALERT, log, err, "sendmsg() failed"); return NGX_ERROR; } return NGX_OK; } ngx_int_t ngx_read_channel(ngx_socket_t s, ngx_channel_t *ch, size_t size, ngx_log_t *log) { ssize_t n; ngx_err_t err; struct iovec iov[1]; struct msghdr msg; #if (NGX_HAVE_MSGHDR_MSG_CONTROL) union { struct cmsghdr cm; char space[CMSG_SPACE(sizeof(int))]; } cmsg; #else int fd; #endif iov[0].iov_base = (char *) ch; iov[0].iov_len = size; msg.msg_name = NULL; msg.msg_namelen = 0; msg.msg_iov = iov; msg.msg_iovlen = 1; #if (NGX_HAVE_MSGHDR_MSG_CONTROL) msg.msg_control = (caddr_t) &cmsg; msg.msg_controllen = sizeof(cmsg); #else msg.msg_accrights = (caddr_t) &fd; msg.msg_accrightslen = sizeof(int); #endif n = recvmsg(s, &msg, 0); if (n == -1) { err = ngx_errno; if (err == NGX_EAGAIN) { return NGX_AGAIN; } ngx_log_error(NGX_LOG_ALERT, log, err, "recvmsg() failed"); return NGX_ERROR; } if (n == 0) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, log, 0, "recvmsg() returned zero"); return NGX_ERROR; } if ((size_t) n < sizeof(ngx_channel_t)) { ngx_log_error(NGX_LOG_ALERT, log, 0, "recvmsg() returned not enough data: %z", n); return NGX_ERROR; } #if (NGX_HAVE_MSGHDR_MSG_CONTROL) if (ch->command == NGX_CMD_OPEN_CHANNEL) { if (cmsg.cm.cmsg_len < (socklen_t) CMSG_LEN(sizeof(int))) { ngx_log_error(NGX_LOG_ALERT, log, 0, "recvmsg() returned too small ancillary data"); return NGX_ERROR; } if (cmsg.cm.cmsg_level != SOL_SOCKET || cmsg.cm.cmsg_type != SCM_RIGHTS) { ngx_log_error(NGX_LOG_ALERT, log, 0, "recvmsg() returned invalid ancillary data " "level %d or type %d", cmsg.cm.cmsg_level, cmsg.cm.cmsg_type); return NGX_ERROR; } /* ch->fd = *(int *) CMSG_DATA(&cmsg.cm); */ ngx_memcpy(&ch->fd, CMSG_DATA(&cmsg.cm), sizeof(int)); } if (msg.msg_flags & (MSG_TRUNC|MSG_CTRUNC)) { ngx_log_error(NGX_LOG_ALERT, log, 0, "recvmsg() truncated data"); } #else if (ch->command == NGX_CMD_OPEN_CHANNEL) { if (msg.msg_accrightslen != sizeof(int)) { ngx_log_error(NGX_LOG_ALERT, log, 0, "recvmsg() returned no ancillary data"); return NGX_ERROR; } ch->fd = fd; } #endif return n; } ngx_int_t ngx_add_channel_event(ngx_cycle_t *cycle, ngx_fd_t fd, ngx_int_t event, ngx_event_handler_pt handler) { ngx_event_t *ev, *rev, *wev; ngx_connection_t *c; c = ngx_get_connection(fd, cycle->log); if (c == NULL) { return NGX_ERROR; } c->pool = cycle->pool; rev = c->read; wev = c->write; rev->log = cycle->log; wev->log = cycle->log; rev->channel = 1; wev->channel = 1; ev = (event == NGX_READ_EVENT) ? rev : wev; ev->handler = handler; if (ngx_add_conn && (ngx_event_flags & NGX_USE_EPOLL_EVENT) == 0) { if (ngx_add_conn(c) == NGX_ERROR) { ngx_free_connection(c); return NGX_ERROR; } } else { if (ngx_add_event(ev, event, 0) == NGX_ERROR) { ngx_free_connection(c); return NGX_ERROR; } } return NGX_OK; } void ngx_close_channel(ngx_fd_t *fd, ngx_log_t *log) { if (close(fd[0]) == -1) { ngx_log_error(NGX_LOG_ALERT, log, ngx_errno, "close() channel failed"); } if (close(fd[1]) == -1) { ngx_log_error(NGX_LOG_ALERT, log, ngx_errno, "close() channel failed"); } }