# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1613069529 -10800
# Node ID 3e83336cda5b66ecd311a3ffeda76868194fb3fe
# Parent  519b55453c454a027febaef0b1ad1026dad14fbb
Reuse of connections in lingering close.

This is particularly important in HTTP/2, where keepalive connections
are closed with lingering.  Before the patch, reusing a keepalive HTTP/2
connection resulted in the connection waiting for lingering close to
remain in the reusable connections queue, preventing ngx_drain_connections()
from closing additional connections.

The patch fixes it by marking the connection reusable again, and so
moving it in the reusable connections queue.  Further, it makes actually
possible to reuse such connections if needed.

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
@@ -3437,6 +3437,9 @@ ngx_http_set_lingering_close(ngx_connect
         return;
     }
 
+    c->close = 0;
+    ngx_reusable_connection(c, 1);
+
     ngx_add_timer(rev, clcf->lingering_timeout);
 
     if (rev->ready) {
@@ -3461,7 +3464,7 @@ ngx_http_lingering_close_handler(ngx_eve
     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http lingering close handler");
 
-    if (rev->timedout) {
+    if (rev->timedout || c->close) {
         ngx_http_close_request(r, 0);
         return;
     }
diff --git a/src/http/v2/ngx_http_v2.c b/src/http/v2/ngx_http_v2.c
--- a/src/http/v2/ngx_http_v2.c
+++ b/src/http/v2/ngx_http_v2.c
@@ -767,6 +767,9 @@ ngx_http_v2_lingering_close(ngx_connecti
         return;
     }
 
+    c->close = 0;
+    ngx_reusable_connection(c, 1);
+
     ngx_add_timer(rev, clcf->lingering_timeout);
 
     if (rev->ready) {
@@ -791,7 +794,7 @@ ngx_http_v2_lingering_close_handler(ngx_
     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http2 lingering close handler");
 
-    if (rev->timedout) {
+    if (rev->timedout || c->close) {
         ngx_http_close_connection(c);
         return;
     }