[PATCH] Core: lingering_close on|off|always

[Maxim Dounin]

# HG changeset patch
# User Maxim Dounin <mdounin at mdounin.ru>
# Date 1309775338 -14400
# Node ID 610e909bb9e29766188aa86fae3abe0bd3432940
# Parent  1c167244d2fdb064c159012c50a7ae3fd1ed254a
Core: lingering_close on|off|always.

Normally nginx uses lingering close if it expects more data from client
(e.g. if it wasn't able to read full request for some reason).  With
"lingering_close always;" it's now possible to always use lingering
close.  This may be beneficial from compatibility point of view though
may consume extra resources.

Additionally, make sure to activate lingering if we are know there are
some pending data either on header_in buffer or in socket buffer (e.g.
pipelined request and no keepalive enabled).

diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -125,6 +125,14 @@ static ngx_conf_enum_t  ngx_http_core_sa
 };
 
 
+static ngx_conf_enum_t  ngx_http_core_lingering_close[] = {
+    { ngx_string("off"), NGX_HTTP_LINGERING_OFF },
+    { ngx_string("on"), NGX_HTTP_LINGERING_ON },
+    { ngx_string("always"), NGX_HTTP_LINGERING_ALWAYS },
+    { ngx_null_string, 0 }
+};
+
+
 static ngx_conf_enum_t  ngx_http_core_if_modified_since[] = {
     { ngx_string("off"), NGX_HTTP_IMS_OFF },
     { ngx_string("exact"), NGX_HTTP_IMS_EXACT },
@@ -530,6 +538,13 @@ static ngx_command_t  ngx_http_core_comm
       0,
       NULL },
 
+    { ngx_string("lingering_close"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_enum_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_core_loc_conf_t, lingering_close),
+      &ngx_http_core_lingering_close },
+
     { ngx_string("lingering_time"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
       ngx_conf_set_msec_slot,
@@ -3117,6 +3132,7 @@ ngx_http_core_create_loc_conf(ngx_conf_t
     clcf->keepalive_timeout = NGX_CONF_UNSET_MSEC;
     clcf->keepalive_header = NGX_CONF_UNSET;
     clcf->keepalive_requests = NGX_CONF_UNSET_UINT;
+    clcf->lingering_close = NGX_CONF_UNSET_UINT;
     clcf->lingering_time = NGX_CONF_UNSET_MSEC;
     clcf->lingering_timeout = NGX_CONF_UNSET_MSEC;
     clcf->resolver_timeout = NGX_CONF_UNSET_MSEC;
@@ -3333,6 +3349,8 @@ ngx_http_core_merge_loc_conf(ngx_conf_t 
                               prev->keepalive_header, 0);
     ngx_conf_merge_uint_value(conf->keepalive_requests,
                               prev->keepalive_requests, 100);
+    ngx_conf_merge_uint_value(conf->lingering_close,
+                              prev->lingering_close, NGX_HTTP_LINGERING_ON);
     ngx_conf_merge_msec_value(conf->lingering_time,
                               prev->lingering_time, 30000);
     ngx_conf_merge_msec_value(conf->lingering_timeout,
diff --git a/src/http/ngx_http_core_module.h b/src/http/ngx_http_core_module.h
--- a/src/http/ngx_http_core_module.h
+++ b/src/http/ngx_http_core_module.h
@@ -33,6 +33,11 @@
 #define NGX_HTTP_SATISFY_ANY            1
 
 
+#define NGX_HTTP_LINGERING_OFF          0
+#define NGX_HTTP_LINGERING_ON           1
+#define NGX_HTTP_LINGERING_ALWAYS       2
+
+
 #define NGX_HTTP_IMS_OFF                0
 #define NGX_HTTP_IMS_EXACT              1
 #define NGX_HTTP_IMS_BEFORE             2
@@ -356,6 +361,7 @@ struct ngx_http_core_loc_conf_s {
     ngx_uint_t    keepalive_requests;      /* keepalive_requests */
     ngx_uint_t    keepalive_disable;       /* keepalive_disable */
     ngx_uint_t    satisfy;                 /* satisfy */
+    ngx_uint_t    lingering_close;         /* lingering_close */
     ngx_uint_t    if_modified_since;       /* if_modified_since */
     ngx_uint_t    client_body_in_file_only; /* client_body_in_file_only */
 
diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -2146,7 +2146,14 @@ ngx_http_finalize_connection(ngx_http_re
         ngx_http_set_keepalive(r);
         return;
 
-    } else if (r->lingering_close && clcf->lingering_timeout > 0) {
+    }
+
+    if (clcf->lingering_close == NGX_HTTP_LINGERING_ALWAYS
+        || (clcf->lingering_close == NGX_HTTP_LINGERING_ON
+            && clcf->lingering_timeout > 0
+            && (r->lingering_close || r->header_in->pos < r->header_in->last
+                || r->connection->read->ready)))
+    {
         ngx_http_set_lingering_close(r);
         return;
     }