void
ngx_postgres_upstream_free_connection(ngx_log_t *log, ngx_connection_t *c,
PGconn *pgconn, ngx_postgres_upstream_srv_conf_t *pgscf)
{
ngx_event_t *rev, *wev;
dd("entering");
PQfinish(pgconn);
if (c) {
rev = c->read;
wev = c->write;
if (rev->timer_set) {
ngx_del_timer(rev);
}
if (wev->timer_set) {
ngx_del_timer(wev);
}
if (ngx_del_conn) {
ngx_del_conn(c, NGX_CLOSE_EVENT);
} else {
if (rev->active || rev->disabled) {
ngx_del_event(rev, NGX_READ_EVENT, NGX_CLOSE_EVENT);
}
if (wev->active || wev->disabled) {
ngx_del_event(wev, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
}
}
if (rev->prev) {
ngx_delete_posted_event(rev);
}
if (wev->prev) {
ngx_delete_posted_event(wev);
}
rev->closed = 1;
wev->closed = 1;
#if defined(nginx_version) && (nginx_version >= 1001004)
if (c->pool) {
ngx_destroy_pool(c->pool);
}
#endif
ngx_free_connection(c);
}
/* free spot in keepalive connection pool */
pgscf->active_conns--;
dd("returning");
}
void
ngx_zeromq_close(ngx_connection_t *c)
{
void *zmq;
if (c->fd == -1) {
return;
}
zmq = c->data;
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
"zmq_close: zmq:%p fd:%d #%d", zmq, c->fd, c->number);
if (c->read->timer_set) {
ngx_del_timer(c->read);
}
if (c->write->timer_set) {
ngx_del_timer(c->write);
}
if (ngx_del_conn) {
ngx_del_conn(c, NGX_CLOSE_EVENT);
} else {
if (c->read->active || c->read->disabled) {
ngx_del_event(c->read, NGX_READ_EVENT, NGX_CLOSE_EVENT);
}
if (c->write->active || c->write->disabled) {
ngx_del_event(c->write, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
}
}
if (c->read->prev) {
ngx_delete_posted_event(c->read);
}
if (c->write->prev) {
ngx_delete_posted_event(c->write);
}
c->read->closed = 1;
c->write->closed = 1;
ngx_reusable_connection(c, 0);
ngx_free_connection(c);
c->fd = (ngx_socket_t) -1;
if (zmq_close(zmq) == -1) {
ngx_zeromq_log_error(ngx_cycle->log, "zmq_close()");
}
}
// 遍历队列，取出队列里的事件，调用对应的handler
// cycle参数只用于记录日志
void
ngx_event_process_posted(ngx_cycle_t *cycle, ngx_queue_t *posted)
{
ngx_queue_t *q;
ngx_event_t *ev;
while (!ngx_queue_empty(posted)) {
// 取队列头节点
q = ngx_queue_head(posted);
// 获取头节点元素，即事件
ev = ngx_queue_data(q, ngx_event_t, queue);
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"posted event %p", ev);
// in ngx_event_posted.h
// 函数宏，从队列里移除
ngx_delete_posted_event(ev);
// 执行事件的回调函数
ev->handler(ev);
}
}
static ngx_int_t
ngx_rtmp_play_stop(ngx_rtmp_session_t *s)
{
ngx_rtmp_play_ctx_t *ctx;
ctx = ngx_rtmp_get_module_ctx(s, ngx_rtmp_play_module);
if (ctx == NULL) {
return NGX_ERROR;
}
ngx_log_debug0(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
"play: stop");
if (ctx->send_evt.timer_set) {
ngx_del_timer(&ctx->send_evt);
}
if (ctx->send_evt.prev) {
ngx_delete_posted_event((&ctx->send_evt));
}
if (ctx->fmt && ctx->fmt->stop &&
ctx->fmt->stop(s, &ctx->file) != NGX_OK)
{
return NGX_ERROR;
}
return NGX_OK;
}
static void destroy_dummy_conn(ngx_connection_t *c)
{
if (c == NULL)
return ;
if (c->read->timer_set) {
ngx_del_timer(c->read);
}
if (c->write->timer_set) {
ngx_del_timer(c->write);
}
if (ngx_del_conn) {
ngx_del_conn(c, 0);
} else {
if (c->read->active || c->read->disabled) {
ngx_del_event(c->read, NGX_READ_EVENT, 0);
}
if (c->write->active || c->write->disabled) {
ngx_del_event(c->write, NGX_WRITE_EVENT, 0);
}
}
if (c->read->prev) {
ngx_delete_posted_event(c->read);
}
if (c->write->prev) {
ngx_delete_posted_event(c->write);
}
close(c->fd);
c->fd = -1;
c->read->closed = 1;
c->write->closed = 1;
free(c->read);
free(c->write);
free(c);
}
void
ngx_event_process_posted(ngx_cycle_t *cycle, ngx_thread_volatile ngx_event_t **posted)
{//延后的处理读写，新连接事件、根据handler进行区分
ngx_event_t *ev;
for ( ;; ) {
ev = (ngx_event_t *) *posted;
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p", ev);
if (ev == NULL) {
return;
}
//从链表里面切断，
ngx_delete_posted_event(ev);
//调用回调函数,监听SOCK为ngx_event_accept，其他的网络SOCK事件回调变化比较大
ev->handler(ev);
}
}
void ngx_event_process_posted(ngx_cycle_t *cycle, ngx_thread_volatile ngx_event_t **posted)
{
ngx_event_t *ev;
for ( ;; ) {
ev = (ngx_event_t *) *posted;
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p", ev);
if (ev == NULL) {
return;
}
ngx_delete_posted_event(ev);
ev->handler(ev);
}
}
void
ngx_event_process_posted(ngx_cycle_t *cycle, ngx_queue_t *posted)
{
ngx_queue_t *q;
ngx_event_t *ev;
while (!ngx_queue_empty(posted)) {
q = ngx_queue_head(posted);
ev = ngx_queue_data(q, ngx_event_t, queue);
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"posted event %p", ev);
ngx_delete_posted_event(ev);
ev->handler(ev);
}
}
void ngx_event_process_posted(ngx_cycle_t *cycle)
{
ngx_event_t *ev;
for ( ;; ) {
ev = (ngx_event_t *) ngx_posted_events;
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"posted event " PTR_FMT, ev);
if (ev == NULL) {
return;
}
ngx_delete_posted_event(ev);
ev->event_handler(ev);
}
}
static void
ngx_live_relay_httpflv_cleanup(void *data)
{
ngx_rtmp_session_t *s;
s = data;
ngx_log_error(NGX_LOG_INFO, s->log, 0, "http flv client, cleanup");
if (s) {
if (s->close.posted) {
ngx_delete_posted_event(&s->close);
}
if (s->finalize_reason == 0) {
s->finalize_reason = NGX_LIVE_FLV_RECV_ERR;
}
ngx_rtmp_finalize_fake_session(s);
}
}
/* 处理post队列中的事件 */
void
ngx_event_process_posted(ngx_cycle_t *cycle, ngx_queue_t *posted)
{
ngx_queue_t *q;
ngx_event_t *ev;
/* 判断队列是否为NULL */
while (!ngx_queue_empty(posted)) {
q = ngx_queue_head(posted);
/* 取出队列中事件 */
ev = ngx_queue_data(q, ngx_event_t, queue);
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"posted event %p", ev);
/* 将事件从队列中删除 */
ngx_delete_posted_event(ev);
/* 处理事件 */
ev->handler(ev);
}
}
void
ngx_close_connection(ngx_connection_t *c)
{
ngx_err_t err;
ngx_uint_t log_error, level;
ngx_socket_t fd;
if (c->fd == (ngx_socket_t) -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0, "connection already closed");
return;
}
//首先将连接的读写事件从定时器中取出
if (c->read->timer_set) {
ngx_del_timer(c->read);
}
if (c->write->timer_set) {
ngx_del_timer(c->write);
}
if (ngx_del_conn) { //将读写事件从epoll中移除
ngx_del_conn(c, NGX_CLOSE_EVENT);
} else {
if (c->read->active || c->read->disabled) {
ngx_del_event(c->read, NGX_READ_EVENT, NGX_CLOSE_EVENT);
}
if (c->write->active || c->write->disabled) {
ngx_del_event(c->write, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
}
}
if (c->read->posted) {
ngx_delete_posted_event(c->read);
}
if (c->write->posted) {
ngx_delete_posted_event(c->write);
}
c->read->closed = 1;
c->write->closed = 1;
ngx_reusable_connection(c, 0);
log_error = c->log_error;
//调用ngx_free_connection方法把表示连接的ngx_connection_t结构体归还给ngx_cycle_t核心结构体的空闲连接池
ngx_free_connection(c);
fd = c->fd;
c->fd = (ngx_socket_t) -1;
if (ngx_close_socket(fd) == -1) { //系统调用close
err = ngx_socket_errno;
if (err == NGX_ECONNRESET || err == NGX_ENOTCONN) {
switch (log_error) {
case NGX_ERROR_INFO:
level = NGX_LOG_INFO;
break;
case NGX_ERROR_ERR:
level = NGX_LOG_ERR;
break;
default:
level = NGX_LOG_CRIT;
}
} else {
level = NGX_LOG_CRIT;
}
/* we use ngx_cycle->log because c->log was in c->pool */
ngx_log_error(level, ngx_cycle->log, err,
ngx_close_socket_n " %d failed", fd);
}
}
ngx_int_t
ngx_event_thread_process_posted(ngx_cycle_t *cycle)
{
ngx_event_t *ev;
for ( ;; ) {
ev = (ngx_event_t *) ngx_posted_events;
for ( ;; ) {
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"posted event %p", ev);
if (ev == NULL) {
return NGX_OK;
}
if (ngx_trylock(ev->lock) == 0) {
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"posted event %p is busy", ev);
ev = ev->next;
continue;
}
if (ev->lock != ev->own_lock) {
if (*(ev->own_lock)) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"the own lock of the posted event %p is busy", ev);
ngx_unlock(ev->lock);
ev = ev->next;
continue;
}
*(ev->own_lock) = 1;
}
ngx_delete_posted_event(ev);
ev->locked = 1;
ev->ready |= ev->posted_ready;
ev->timedout |= ev->posted_timedout;
ev->pending_eof |= ev->posted_eof;
#if (NGX_HAVE_KQUEUE)
ev->kq_errno |= ev->posted_errno;
#endif
if (ev->posted_available) {
ev->available = ev->posted_available;
}
ev->posted_ready = 0;
ev->posted_timedout = 0;
ev->posted_eof = 0;
#if (NGX_HAVE_KQUEUE)
ev->posted_errno = 0;
#endif
ev->posted_available = 0;
ngx_mutex_unlock(ngx_posted_events_mutex);
ev->handler(ev);
ngx_mutex_lock(ngx_posted_events_mutex);
if (ev->locked) {
ngx_unlock(ev->lock);
if (ev->lock != ev->own_lock) {
ngx_unlock(ev->own_lock);
}
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"posted event %p is done", ev);
break;
}
}
}
void ngx_close_connection(ngx_connection_t *c)
{
ngx_socket_t fd;
if (c->pool == NULL)
{
ngx_log_error(NGX_LOG_ALERT, c->log, 0, "connection already closed");
return;
}
#if (NGX_OPENSSL)
if (c->ssl)
{
if (ngx_ssl_shutdown(c) == NGX_AGAIN)
{
c->read->event_handler = ngx_ssl_close_handler;
c->write->event_handler = ngx_ssl_close_handler;
return;
}
}
#endif
if (c->read->timer_set)
{
ngx_del_timer(c->read);
}
if (c->write->timer_set)
{
ngx_del_timer(c->write);
}
if (ngx_del_conn)
{
ngx_del_conn(c, NGX_CLOSE_EVENT);
}
else
{
if (c->read->active || c->read->disabled)
{
ngx_del_event(c->read, NGX_READ_EVENT, NGX_CLOSE_EVENT);
}
if (c->write->active || c->write->disabled)
{
ngx_del_event(c->write, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
}
}
#if (NGX_THREADS)
/*
* we have to clean the connection information before the closing
* because another thread may reopen the same file descriptor
* before we clean the connection
*/
if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_OK)
{
if (c->read->prev)
{
ngx_delete_posted_event(c->read);
}
if (c->write->prev)
{
ngx_delete_posted_event(c->write);
}
c->read->closed = 1;
c->write->closed = 1;
if (c->single_connection)
{
ngx_unlock(&c->lock);
c->read->locked = 0;
c->write->locked = 0;
}
ngx_mutex_unlock(ngx_posted_events_mutex);
}
#else
if (c->read->prev)
{
ngx_delete_posted_event(c->read);
}
if (c->write->prev)
{
ngx_delete_posted_event(c->write);
}
c->read->closed = 1;
c->write->closed = 1;
#endif
fd = c->fd;
c->fd = (ngx_socket_t) -1;
c->data = NULL;
ngx_destroy_pool(c->pool);
if (ngx_close_socket(fd) == -1)
{
/* we use ngx_cycle->log because c->log was in c->pool */
ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_socket_errno,
ngx_close_socket_n " failed");
}
}
void
ngx_zeromq_close(ngx_zeromq_connection_t *zc)
{
ngx_connection_t *c;
c = &zc->connection;
if (c->fd == -1) {
return;
}
ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0,
"zmq_close: fd:%d #%d zc:%p zmq:%p",
c->fd, c->number, zc, zc->socket);
if (c->read->timer_set) {
ngx_del_timer(c->read);
}
if (c->write->timer_set) {
ngx_del_timer(c->write);
}
if (ngx_del_conn) {
ngx_del_conn(c, NGX_CLOSE_EVENT);
} else {
if (c->read->active || c->read->disabled) {
ngx_del_event(c->read, NGX_READ_EVENT, NGX_CLOSE_EVENT);
}
if (c->write->active || c->write->disabled) {
ngx_del_event(c->write, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
}
}
#if (nginx_version >= 1007005)
if (c->read->posted) {
#else
if (c->read->prev) {
#endif
ngx_delete_posted_event(c->read);
}
#if (nginx_version >= 1007005)
if (c->write->posted) {
#else
if (c->write->prev) {
#endif
ngx_delete_posted_event(c->write);
}
c->read->closed = 1;
c->write->closed = 1;
ngx_reusable_connection(zc->connection_ptr, 0);
ngx_free_connection(zc->connection_ptr);
c->fd = (ngx_socket_t) -1;
zc->connection_ptr->fd = (ngx_socket_t) -1;
if (zmq_close(zc->socket) == -1) {
ngx_zeromq_log_error(ngx_cycle->log, "zmq_close()");
}
zc->socket = NULL;
}
static void
ngx_zeromq_event_handler(ngx_event_t *ev)
{
ngx_zeromq_connection_t *zc;
ngx_connection_t *c;
void *zmq;
int events;
size_t esize;
/*
* ZeroMQ notifies us about new events in edge-triggered fashion
* by changing state of the notification socket to read-ready.
*
* Write-readiness doesn't indicate anything and can be ignored.
*/
if (ev->write) {
return;
}
zc = ev->data;
zc = zc->send;
esize = sizeof(int);
#if (NGX_DEBUG)
if (zc->recv != zc->send) {
zmq = zc->request_sent ? zc->socket : zc->recv->socket;
if (zmq_getsockopt(zmq, ZMQ_EVENTS, &events, &esize) == -1) {
ngx_zeromq_log_error(ev->log, "zmq_getsockopt(ZMQ_EVENTS)");
ev->error = 1;
return;
}
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"zmq_event: %s:%d (ignored)",
zc->request_sent ? "send" : "recv", events);
}
#endif
zmq = zc->request_sent ? zc->recv->socket : zc->socket;
if (zmq_getsockopt(zmq, ZMQ_EVENTS, &events, &esize) == -1) {
ngx_zeromq_log_error(ev->log, "zmq_getsockopt(ZMQ_EVENTS)");
ev->error = 1;
return;
}
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"zmq_event: %s:%d",
zc->request_sent ? "recv" : "send", events);
c = &zc->connection;
if (zc->request_sent) {
c->read->ready = events & ZMQ_POLLIN ? 1 : 0;
if (c->read->ready) {
zc->handler(c->read);
}
} else {
c->write->ready = events & ZMQ_POLLOUT ? 1 : 0;
if (c->write->ready) {
zc->handler(c->write);
}
}
}
static ssize_t
ngx_zeromq_sendmsg(void *zmq, ngx_event_t *ev, zmq_msg_t *msg, int flags)
{
size_t size;
size = zmq_msg_size(msg);
for (;;) {
if (zmq_msg_send(msg, zmq, ZMQ_DONTWAIT|flags) == -1) {
if (ngx_errno == NGX_EAGAIN) {
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"zmq_send: not ready");
ev->ready = 0;
return NGX_AGAIN;
}
if (ngx_errno == NGX_EINTR) {
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"zmq_send: interrupted");
ev->ready = 0;
continue;
}
ngx_zeromq_log_error(ev->log, "zmq_msg_send()");
ev->error = 1;
return NGX_ERROR;
}
break;
}
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"zmq_send: %uz eom:%d", size, flags != ZMQ_SNDMORE);
return size;
}
void
ngx_close_connection(ngx_connection_t *c)
{
ngx_err_t err;
ngx_uint_t log_error, level;
ngx_socket_t fd;
if (c->fd == (ngx_socket_t) -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0, "connection already closed");
return;
}
if (c->read->timer_set) {
ngx_del_timer(c->read);
}
if (c->write->timer_set) {
ngx_del_timer(c->write);
}
if (!c->shared) {
if (ngx_del_conn) {
ngx_del_conn(c, NGX_CLOSE_EVENT);
} else {
if (c->read->active || c->read->disabled) {
ngx_del_event(c->read, NGX_READ_EVENT, NGX_CLOSE_EVENT);
}
if (c->write->active || c->write->disabled) {
ngx_del_event(c->write, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
}
}
}
if (c->read->posted) {
ngx_delete_posted_event(c->read);
}
if (c->write->posted) {
ngx_delete_posted_event(c->write);
}
c->read->closed = 1;
c->write->closed = 1;
ngx_reusable_connection(c, 0);
log_error = c->log_error;
ngx_free_connection(c);
fd = c->fd;
c->fd = (ngx_socket_t) -1;
if (c->shared) {
return;
}
if (ngx_close_socket(fd) == -1) {
err = ngx_socket_errno;
if (err == NGX_ECONNRESET || err == NGX_ENOTCONN) {
switch (log_error) {
case NGX_ERROR_INFO:
level = NGX_LOG_INFO;
break;
case NGX_ERROR_ERR:
level = NGX_LOG_ERR;
break;
default:
level = NGX_LOG_CRIT;
}
} else {
level = NGX_LOG_CRIT;
}
ngx_log_error(level, c->log, err, ngx_close_socket_n " %d failed", fd);
}
}
void
ngx_close_connection(ngx_connection_t *c)
{
ngx_err_t err;
ngx_uint_t log_error, level;
ngx_socket_t fd;
if (c->fd == -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0, "connection already closed");
return;
}
if (c->read->timer_set) {
ngx_del_timer(c->read);
}
if (c->write->timer_set) {
ngx_del_timer(c->write);
}
if (ngx_del_conn) {
ngx_del_conn(c, NGX_CLOSE_EVENT);
} else {
if (c->read->active || c->read->disabled) {
ngx_del_event(c->read, NGX_READ_EVENT, NGX_CLOSE_EVENT);
}
if (c->write->active || c->write->disabled) {
ngx_del_event(c->write, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
}
}
#if (NGX_THREADS)
/*
* we have to clean the connection information before the closing
* because another thread may reopen the same file descriptor
* before we clean the connection
*/
ngx_mutex_lock(ngx_posted_events_mutex);
if (c->read->prev) {
ngx_delete_posted_event(c->read);
}
if (c->write->prev) {
ngx_delete_posted_event(c->write);
}
c->read->closed = 1;
c->write->closed = 1;
if (c->single_connection) {
ngx_unlock(&c->lock);
c->read->locked = 0;
c->write->locked = 0;
}
ngx_mutex_unlock(ngx_posted_events_mutex);
#else
if (c->read->prev) {
ngx_delete_posted_event(c->read);
}
if (c->write->prev) {
ngx_delete_posted_event(c->write);
}
c->read->closed = 1;
c->write->closed = 1;
#endif
ngx_reusable_connection(c, 0);
log_error = c->log_error;
ngx_free_connection(c);
fd = c->fd;
c->fd = (ngx_socket_t) -1;
if (ngx_close_socket(fd) == -1) {
err = ngx_socket_errno;
if (err == NGX_ECONNRESET || err == NGX_ENOTCONN) {
switch (log_error) {
case NGX_ERROR_INFO:
level = NGX_LOG_INFO;
break;
case NGX_ERROR_ERR:
level = NGX_LOG_ERR;
break;
default:
level = NGX_LOG_CRIT;
}
} else {
level = NGX_LOG_CRIT;
}
/* we use ngx_cycle->log because c->log was in c->pool */
ngx_log_error(level, ngx_cycle->log, err,
ngx_close_socket_n " %d failed", fd);
}
}
/*
ngx_http_close_request方法是更高层的用于关闭请求的方法，当然，HTTP模块一般也不会直接调用它的。在上面几节中反复提到的引用计数，
就是由ngx_http_close_request方法负责检测的，同时它会在引用计数清零时正式调用ngx_http_free_request方法和ngx_http_close_connection(ngx_close_connection)
方法来释放请求、关闭连接,见ngx_http_close_request
*/
void
ngx_close_connection(ngx_connection_t *c)
{
ngx_err_t err;
ngx_uint_t log_error, level;
ngx_socket_t fd;
if (c->fd == (ngx_socket_t) -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0, "connection already closed");
return;
}
/*
首先将连接的读/写事件从定时器中取出。实际上就是检查读/写事件的time_set标志位，如果为1，则证明事件在定时器中，那么需要调
用ngx_del_timer方法把事件从定时器中移除。
*/
if (c->read->timer_set) {
ngx_del_timer(c->read, NGX_FUNC_LINE);
}
if (c->write->timer_set) {
ngx_del_timer(c->write, NGX_FUNC_LINE);
}
/*
调用ngx_del_conn宏（或者ngx_del_event宏）将读/写事件从epoll中移除。实际上就是调用ngx_event_actions_t接口
中的del_conn方法，当事件模块是epoll模块时，就是从epoll中移除这个连接的读/写事件。同时，如果这个事件在ngx_posted_accept_events或
者ngx_posted_events队列中，还需要调用ngx_delete_posted_event宏把事件从post事件队列中移除。
*/
if (ngx_del_conn) { //ngx_epoll_del_connection
ngx_del_conn(c, NGX_CLOSE_EVENT);
} else {
if (c->read->active || c->read->disabled) {
ngx_del_event(c->read, NGX_READ_EVENT, NGX_CLOSE_EVENT); //ngx_epoll_del_event
}
if (c->write->active || c->write->disabled) {
ngx_del_event(c->write, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
}
}
if (c->read->posted) {
ngx_delete_posted_event(c->read);
}
if (c->write->posted) {
ngx_delete_posted_event(c->write);
}
c->read->closed = 1;
c->write->closed = 1;
ngx_reusable_connection(c, 0);
log_error = c->log_error;
/*
调用ngx_free_connection方法把表示连接的ngx_connection-t结构体归还给ngx_
cycle_t核心结构体的空闲连接池free connections。
*/
ngx_free_connection(c);
fd = c->fd;
c->fd = (ngx_socket_t) -1;
ngx_log_debugall(ngx_cycle->log, 0, "close socket:%d", fd);
//调用系统提供的close方法关闭这个TCP连接套接字。
if (ngx_close_socket(fd) == -1) {
err = ngx_socket_errno;
if (err == NGX_ECONNRESET || err == NGX_ENOTCONN) {
switch (log_error) {
case NGX_ERROR_INFO:
level = NGX_LOG_INFO;
break;
case NGX_ERROR_ERR:
level = NGX_LOG_ERR;
break;
default:
level = NGX_LOG_CRIT;
}
} else {
level = NGX_LOG_CRIT;
}
/* we use ngx_cycle->log because c->log was in c->pool */
//由于c已经在前面释放了，因此不能再用C->log了
ngx_log_error(level, ngx_cycle->log, err,
ngx_close_socket_n " %d failed", fd);
}
}