void ngx_event_recvmsg(ngx_event_t *ev)
{
ssize_t n;
ngx_log_t *log;
ngx_err_t err;
ngx_event_t *rev, *wev;
WSABUF wsabuf[1];
u_long bytes, flags;
ngx_listening_t *ls;
ngx_event_conf_t *ecf;
ngx_connection_t *c, *lc;
u_char sa[NGX_SOCKADDRLEN];
socklen_t socklen = NGX_SOCKADDRLEN;
static u_char buffer[65535];
if (ev->timedout) {
if (ngx_enable_accept_events((ngx_cycle_t *) ngx_cycle) != NGX_OK) {
return;
}
ev->timedout = 0;
}
ecf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_event_core_module);
ev->available = ecf->multi_accept;
lc = ev->data;
ls = lc->listening;
ev->ready = 0;
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"WSARecvFrom on %V, ready: %d", &ls->addr_text, ev->available);
do {
ngx_memzero(&wsabuf, sizeof(WSABUF));
wsabuf[0].buf = (void *) buffer;
wsabuf[0].len = sizeof(buffer);
flags = 0;
bytes = 0;
n = WSARecvFrom(lc->fd, &wsabuf, 1, &bytes, &flags,
(struct sockaddr *) sa,
(LPINT) &socklen, NULL, NULL);
if (n == SOCKET_ERROR) {
err = ngx_socket_errno;
if (err == NGX_EAGAIN) {
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err,
"WSARecvFrom() not ready");
return;
}
ngx_log_error(NGX_LOG_ALERT, ev->log, err, "WSARecvFrom() failed");
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(lc->fd, ev->log);
if (c == NULL) {
return;
}
c->shared = 1;
c->type = SOCK_DGRAM;
c->socklen = sizeof(sa);
#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, c->socklen);
if (c->sockaddr == NULL) {
ngx_close_accepted_connection(c);
return;
}
ngx_memcpy(c->sockaddr, &sa, c->socklen);
log = ngx_palloc(c->pool, sizeof(ngx_log_t));
if (log == NULL) {
ngx_close_accepted_connection(c);
return;
}
*log = ls->log;
c->send = ngx_udp_send;
c->log = log;
c->pool->log = log;
c->listening = ls;
c->local_sockaddr = ls->sockaddr;
c->local_socklen = ls->socklen;
n = bytes;
c->buffer = ngx_create_temp_buf(c->pool, n);
if (c->buffer == NULL) {
ngx_close_accepted_connection(c);
return;
}
c->buffer->last = ngx_cpymem(c->buffer->last, buffer, n);
rev = c->read;
wev = c->write;
wev->ready = 1;
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 (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->socklen,
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)
{
ngx_str_t addr;
u_char text[NGX_SOCKADDR_STRLEN];
ngx_debug_accepted_connection(ecf, c);
if (log->log_level & NGX_LOG_DEBUG_EVENT) {
addr.data = text;
addr.len = ngx_sock_ntop(c->sockaddr, c->socklen, text,
NGX_SOCKADDR_STRLEN, 1);
ngx_log_debug4(NGX_LOG_DEBUG_EVENT, log, 0,
"*%uA WSARecvFrom: %V fd:%d n:%z",
c->number, &addr, c->fd, n);
}
}
#endif
log->data = NULL;
log->handler = NULL;
ls->handler(c);
} while (ev->available);
}
void
ngx_event_accept(ngx_event_t *ev)
{
socklen_t socklen;
ngx_err_t err;
ngx_log_t *log;
ngx_uint_t level;
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
if (ev->timedout) {
if (ngx_enable_accept_events((ngx_cycle_t *) ngx_cycle) != NGX_OK) {
return;
}
ev->timedout = 0;
}
ecf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_event_core_module);
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 == (ngx_socket_t) -1) {
err = ngx_socket_errno;
if (err == NGX_EAGAIN) {
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err,
"accept() not ready");
return;
}
level = NGX_LOG_ALERT;
if (err == NGX_ECONNABORTED) {
level = NGX_LOG_ERR;
} else if (err == NGX_EMFILE || err == NGX_ENFILE) {
level = NGX_LOG_CRIT;
}
#if (NGX_HAVE_ACCEPT4)
ngx_log_error(level, 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(level, ev->log, err, "accept() failed");
#endif
if (err == NGX_ECONNABORTED) {
if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
ev->available--;
}
if (ev->available) {
continue;
}
}
if (err == NGX_EMFILE || err == NGX_ENFILE) {
if (ngx_disable_accept_events((ngx_cycle_t *) ngx_cycle, 1)
!= NGX_OK)
{
return;
}
if (ngx_use_accept_mutex) {
if (ngx_accept_mutex_held) {
ngx_shmtx_unlock(&ngx_accept_mutex);
ngx_accept_mutex_held = 0;
}
ngx_accept_disabled = 1;
} else {
ngx_add_timer(ev, ecf->accept_mutex_delay);
}
}
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;
}
c->type = SOCK_STREAM;
#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 iocp and non-blocking mode for others */
if (ngx_inherited_nonblocking) {
if (ngx_event_flags & NGX_USE_IOCP_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_IOCP_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->local_socklen = ls->socklen;
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_IOCP_EVENT) {
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 (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->socklen,
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)
{
ngx_str_t addr;
u_char text[NGX_SOCKADDR_STRLEN];
ngx_debug_accepted_connection(ecf, c);
if (log->log_level & NGX_LOG_DEBUG_EVENT) {
addr.data = text;
addr.len = ngx_sock_ntop(c->sockaddr, c->socklen, text,
NGX_SOCKADDR_STRLEN, 1);
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, log, 0,
"*%uA accept: %V fd:%d", c->number, &addr, s);
}
}
#endif
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);
}
void
ngx_event_recvmsg(ngx_event_t *ev)
{
ssize_t n;
ngx_log_t *log;
ngx_err_t err;
ngx_event_t *rev, *wev;
struct iovec iov[1];
struct msghdr msg;
ngx_listening_t *ls;
ngx_event_conf_t *ecf;
ngx_connection_t *c, *lc;
u_char sa[NGX_SOCKADDRLEN];
static u_char buffer[65535];
#if (NGX_HAVE_MSGHDR_MSG_CONTROL)
#if (NGX_HAVE_IP_RECVDSTADDR)
u_char msg_control[CMSG_SPACE(sizeof(struct in_addr))];
#elif (NGX_HAVE_IP_PKTINFO)
u_char msg_control[CMSG_SPACE(sizeof(struct in_pktinfo))];
#endif
#if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO)
u_char msg_control6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
#endif
#endif
if (ev->timedout) {
if (ngx_enable_accept_events((ngx_cycle_t *) ngx_cycle) != NGX_OK) {
return;
}
ev->timedout = 0;
}
ecf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_event_core_module);
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,
"recvmsg on %V, ready: %d", &ls->addr_text, ev->available);
do {
ngx_memzero(&msg, sizeof(struct msghdr));
iov[0].iov_base = (void *) buffer;
iov[0].iov_len = sizeof(buffer);
msg.msg_name = &sa;
msg.msg_namelen = sizeof(sa);
msg.msg_iov = iov;
msg.msg_iovlen = 1;
#if (NGX_HAVE_MSGHDR_MSG_CONTROL)
if (ls->wildcard) {
#if (NGX_HAVE_IP_RECVDSTADDR || NGX_HAVE_IP_PKTINFO)
if (ls->sockaddr->sa_family == AF_INET) {
msg.msg_control = &msg_control;
msg.msg_controllen = sizeof(msg_control);
}
#endif
#if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO)
if (ls->sockaddr->sa_family == AF_INET6) {
msg.msg_control = &msg_control6;
msg.msg_controllen = sizeof(msg_control6);
}
#endif
}
#endif
n = recvmsg(lc->fd, &msg, 0);
if (n == -1) {
err = ngx_socket_errno;
if (err == NGX_EAGAIN) {
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err,
"recvmsg() not ready");
return;
}
ngx_log_error(NGX_LOG_ALERT, ev->log, err, "recvmsg() failed");
return;
}
#if (NGX_STAT_STUB)
(void) ngx_atomic_fetch_add(ngx_stat_accepted, 1);
#endif
#if (NGX_HAVE_MSGHDR_MSG_CONTROL)
if (msg.msg_flags & (MSG_TRUNC|MSG_CTRUNC)) {
ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
"recvmsg() truncated data");
continue;
}
#endif
ngx_accept_disabled = ngx_cycle->connection_n / 8
- ngx_cycle->free_connection_n;
c = ngx_get_connection(lc->fd, ev->log);
if (c == NULL) {
return;
}
c->shared = 1;
c->type = SOCK_DGRAM;
c->socklen = msg.msg_namelen;
#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, c->socklen);
if (c->sockaddr == NULL) {
ngx_close_accepted_connection(c);
return;
}
ngx_memcpy(c->sockaddr, msg.msg_name, c->socklen);
log = ngx_palloc(c->pool, sizeof(ngx_log_t));
if (log == NULL) {
ngx_close_accepted_connection(c);
return;
}
*log = ls->log;
c->send = ngx_udp_send;
c->log = log;
c->pool->log = log;
c->listening = ls;
c->local_sockaddr = ls->sockaddr;
c->local_socklen = ls->socklen;
#if (NGX_HAVE_MSGHDR_MSG_CONTROL)
if (ls->wildcard) {
struct cmsghdr *cmsg;
struct sockaddr *sockaddr;
sockaddr = ngx_palloc(c->pool, c->local_socklen);
if (sockaddr == NULL) {
ngx_close_accepted_connection(c);
return;
}
ngx_memcpy(sockaddr, c->local_sockaddr, c->local_socklen);
c->local_sockaddr = sockaddr;
for (cmsg = CMSG_FIRSTHDR(&msg);
cmsg != NULL;
cmsg = CMSG_NXTHDR(&msg, cmsg))
{
#if (NGX_HAVE_IP_RECVDSTADDR)
if (cmsg->cmsg_level == IPPROTO_IP
&& cmsg->cmsg_type == IP_RECVDSTADDR
&& sockaddr->sa_family == AF_INET)
{
struct in_addr *addr;
struct sockaddr_in *sin;
addr = (struct in_addr *) CMSG_DATA(cmsg);
sin = (struct sockaddr_in *) sockaddr;
sin->sin_addr = *addr;
break;
}
#elif (NGX_HAVE_IP_PKTINFO)
if (cmsg->cmsg_level == IPPROTO_IP
&& cmsg->cmsg_type == IP_PKTINFO
&& sockaddr->sa_family == AF_INET)
{
struct in_pktinfo *pkt;
struct sockaddr_in *sin;
pkt = (struct in_pktinfo *) CMSG_DATA(cmsg);
sin = (struct sockaddr_in *) sockaddr;
sin->sin_addr = pkt->ipi_addr;
break;
}
#endif
#if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO)
if (cmsg->cmsg_level == IPPROTO_IPV6
&& cmsg->cmsg_type == IPV6_PKTINFO
&& sockaddr->sa_family == AF_INET6)
{
struct in6_pktinfo *pkt6;
struct sockaddr_in6 *sin6;
pkt6 = (struct in6_pktinfo *) CMSG_DATA(cmsg);
sin6 = (struct sockaddr_in6 *) sockaddr;
sin6->sin6_addr = pkt6->ipi6_addr;
break;
}
#endif
}
}
#endif
c->buffer = ngx_create_temp_buf(c->pool, n);
if (c->buffer == NULL) {
ngx_close_accepted_connection(c);
return;
}
c->buffer->last = ngx_cpymem(c->buffer->last, buffer, n);
rev = c->read;
wev = c->write;
wev->ready = 1;
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 (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->socklen,
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)
{
ngx_str_t addr;
u_char text[NGX_SOCKADDR_STRLEN];
ngx_debug_accepted_connection(ecf, c);
if (log->log_level & NGX_LOG_DEBUG_EVENT) {
addr.data = text;
addr.len = ngx_sock_ntop(c->sockaddr, c->socklen, text,
NGX_SOCKADDR_STRLEN, 1);
ngx_log_debug4(NGX_LOG_DEBUG_EVENT, log, 0,
"*%uA recvmsg: %V fd:%d n:%z",
c->number, &addr, c->fd, n);
}
}
#endif
log->data = NULL;
log->handler = NULL;
ls->handler(c);
if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
ev->available -= n;
}
} while (ev->available);
}
// 仅接受tcp连接
// ngx_event_process_init里设置接受连接的回调函数为ngx_event_accept，可以接受连接
// 监听端口上收到连接请求时的回调函数，即事件handler
// 从cycle的连接池里获取连接
// 关键操作 ls->handler(c);调用其他模块的业务handler
void
ngx_event_accept(ngx_event_t *ev)
{
socklen_t socklen;
ngx_err_t err;
ngx_log_t *log;
ngx_uint_t level;
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
// 事件已经超时
if (ev->timedout) {
// 遍历监听端口列表，重新加入epoll连接事件
if (ngx_enable_accept_events((ngx_cycle_t *) ngx_cycle) != NGX_OK) {
return;
}
// 保证监听不超时
ev->timedout = 0;
}
ecf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_event_core_module);
// rtsig在nginx 1.9.x已经删除
if (!(ngx_event_flags & NGX_USE_KQUEUE_EVENT)) {
// epoll是否允许尽可能接受多个请求
ev->available = ecf->multi_accept;
}
// 事件的连接对象
lc = ev->data;
// 事件对应的监听端口对象
ls = lc->listening;
// 此时还没有数据可读
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;
// 调用accept接受连接，返回socket对象
#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
// 接受连接出错
if (s == (ngx_socket_t) -1) {
err = ngx_socket_errno;
// EAGAIN，此时已经没有新的连接，用于multi_accept
if (err == NGX_EAGAIN) {
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err,
"accept() not ready");
return;
}
level = NGX_LOG_ALERT;
if (err == NGX_ECONNABORTED) {
level = NGX_LOG_ERR;
} else if (err == NGX_EMFILE || err == NGX_ENFILE) {
level = NGX_LOG_CRIT;
}
#if (NGX_HAVE_ACCEPT4)
ngx_log_error(level, 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(level, ev->log, err, "accept() failed");
#endif
if (err == NGX_ECONNABORTED) {
if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
ev->available--;
}
if (ev->available) {
continue;
}
}
// 系统的文件句柄数用完了
if (err == NGX_EMFILE || err == NGX_ENFILE) {
// 遍历监听端口列表，删除epoll监听连接事件，不接受请求
if (ngx_disable_accept_events((ngx_cycle_t *) ngx_cycle, 1)
!= NGX_OK)
{
return;
}
// 解锁负载均衡，允许其他进程接受请求
if (ngx_use_accept_mutex) {
if (ngx_accept_mutex_held) {
ngx_shmtx_unlock(&ngx_accept_mutex);
ngx_accept_mutex_held = 0;
}
//未持有锁，暂时不接受请求
ngx_accept_disabled = 1;
} else {
// 不使用负载均衡
// 等待一下，再次尝试接受请求
ngx_add_timer(ev, ecf->accept_mutex_delay);
}
}
return;
} // 接受连接出错
#if (NGX_STAT_STUB)
(void) ngx_atomic_fetch_add(ngx_stat_accepted, 1);
#endif
// 此时accept返回了一个socket描述符s
// ngx_accept_disabled是总连接数的1/8-空闲连接数
// 也就是说空闲连接数小于总数的1/8,那么就暂时停止接受连接
ngx_accept_disabled = ngx_cycle->connection_n / 8
- ngx_cycle->free_connection_n;
// 从全局变量ngx_cycle里获取空闲链接，即free_connections链表
c = ngx_get_connection(s, ev->log);
// 如果没有空闲连接，那么关闭socket，无法处理请求
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;
}
// 1.10连接对象里新的字段，表示连接类型是tcp
c->type = SOCK_STREAM;
#if (NGX_STAT_STUB)
(void) ngx_atomic_fetch_add(ngx_stat_active, 1);
#endif
// 创建连接使用的内存池
// stream模块设置连接的内存池是256bytes，不可配置
// http模块可以在ngx_http_core_srv_conf_t里配置
c->pool = ngx_create_pool(ls->pool_size, ev->log);
if (c->pool == NULL) {
ngx_close_accepted_connection(c);
return;
}
// 拷贝客户端sockaddr
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 iocp and non-blocking mode for others */
// 设置socket为非阻塞
if (ngx_inherited_nonblocking) {
if (ngx_event_flags & NGX_USE_IOCP_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_IOCP_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;
// 连接的收发数据函数
// #define ngx_recv ngx_io.recv
// #define ngx_recv_chain ngx_io.recv_chain
// ngx_posix_init.c里初始化为linux的底层接口
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;
// 设置其他的成员
c->socklen = socklen;
c->listening = ls;
c->local_sockaddr = ls->sockaddr;
c->local_socklen = ls->socklen;
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
// 连接相关的读写事件
rev = c->read;
wev = c->write;
// 建立连接后是可写的
wev->ready = 1;
// rtsig在nginx 1.9.x已经删除
if (ngx_event_flags & NGX_USE_IOCP_EVENT) {
rev->ready = 1;
}
// 如果listen使用了deferred，那么建立连接时就已经有数据可读了
// 否则需要自己再加读事件，当有数据来时才能读取
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
*/
// 连接计数器增加
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 (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->socklen,
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)
{
ngx_str_t addr;
u_char text[NGX_SOCKADDR_STRLEN];
ngx_debug_accepted_connection(ecf, c);
if (log->log_level & NGX_LOG_DEBUG_EVENT) {
addr.data = text;
addr.len = ngx_sock_ntop(c->sockaddr, c->socklen, text,
NGX_SOCKADDR_STRLEN, 1);
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, log, 0,
"*%uA accept: %V fd:%d", c->number, &addr, s);
}
}
#endif
// 连接的读写事件都加入epoll，即有读写都会由epoll收集事件并处理
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;
// 接受连接，收到请求的回调函数
// 在http模块里是http.c:ngx_http_init_connection
// stream模块里是ngx_stream_init_connection
ls->handler(c);
// epoll不处理
if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
ev->available--;
}
// 如果ev->available = ecf->multi_accept;
// epoll尽可能接受多个请求，直至accept出错EAGAIN，即无新连接请求
// 否则epoll只接受一个请求后即退出循环
} while (ev->available);
}
