diff src/event/ngx_event_accept.c @ 6153:4f6efabcb09b

The "reuseport" option of the "listen" directive. When configured, an individual listen socket on a given address is created for each worker process. This allows to reduce in-kernel lock contention on configurations with high accept rates, resulting in better performance. As of now it works on Linux and DragonFly BSD. Note that on Linux incoming connection requests are currently tied up to a specific listen socket, and if some sockets are closed, connection requests will be reset, see https://lwn.net/Articles/542629/. With nginx, this may happen if the number of worker processes is reduced. There is no such problem on DragonFly BSD. Based on previous work by Sepherosa Ziehau and Yingqi Lu.
author Maxim Dounin <mdounin@mdounin.ru>
date Wed, 20 May 2015 15:51:56 +0300
parents adba26ff70b5
children 8f038068f4bc
line wrap: on
line diff
--- a/src/event/ngx_event_accept.c
+++ b/src/event/ngx_event_accept.c
@@ -11,7 +11,7 @@
 
 
 static ngx_int_t ngx_enable_accept_events(ngx_cycle_t *cycle);
-static ngx_int_t ngx_disable_accept_events(ngx_cycle_t *cycle);
+static ngx_int_t ngx_disable_accept_events(ngx_cycle_t *cycle, ngx_uint_t all);
 static void ngx_close_accepted_connection(ngx_connection_t *c);
 
 
@@ -109,7 +109,7 @@ ngx_event_accept(ngx_event_t *ev)
             }
 
             if (err == NGX_EMFILE || err == NGX_ENFILE) {
-                if (ngx_disable_accept_events((ngx_cycle_t *) ngx_cycle)
+                if (ngx_disable_accept_events((ngx_cycle_t *) ngx_cycle, 1)
                     != NGX_OK)
                 {
                     return;
@@ -390,7 +390,7 @@ ngx_trylock_accept_mutex(ngx_cycle_t *cy
                    "accept mutex lock failed: %ui", ngx_accept_mutex_held);
 
     if (ngx_accept_mutex_held) {
-        if (ngx_disable_accept_events(cycle) == NGX_ERROR) {
+        if (ngx_disable_accept_events(cycle, 0) == NGX_ERROR) {
             return NGX_ERROR;
         }
 
@@ -413,7 +413,7 @@ ngx_enable_accept_events(ngx_cycle_t *cy
 
         c = ls[i].connection;
 
-        if (c->read->active) {
+        if (c == NULL || c->read->active) {
             continue;
         }
 
@@ -427,7 +427,7 @@ ngx_enable_accept_events(ngx_cycle_t *cy
 
 
 static ngx_int_t
-ngx_disable_accept_events(ngx_cycle_t *cycle)
+ngx_disable_accept_events(ngx_cycle_t *cycle, ngx_uint_t all)
 {
     ngx_uint_t         i;
     ngx_listening_t   *ls;
@@ -438,10 +438,23 @@ ngx_disable_accept_events(ngx_cycle_t *c
 
         c = ls[i].connection;
 
-        if (!c->read->active) {
+        if (c == NULL || !c->read->active) {
             continue;
         }
 
+#if (NGX_HAVE_REUSEPORT)
+
+        /*
+         * do not disable accept on worker's own sockets
+         * when disabling accept events due to accept mutex
+         */
+
+        if (ls[i].reuseport && !all) {
+            continue;
+        }
+
+#endif
+
         if (ngx_del_event(c->read, NGX_READ_EVENT, NGX_DISABLE_EVENT)
             == NGX_ERROR)
         {