[PATCH]HTTP/2 connection not properly closing during graceful shutdown

[kasei at kasei.im]

Hello,

Thanks for your confirmation and explanations.

The following is a modified patch. In my test it would send GOAWAY(on
stream id 0), same as the previous one, but call
ngx_http_v2_finalize_connection instead of set c->close.

# HG changeset patch
# User Kasei Wang <kasei at kasei.im>
# Date 1714965008 -28800
#      Mon May 06 11:10:08 2024 +0800
# Branch help
# Node ID 70b6b6b69e6fd3a0d03de004acf45bad16b03a9c
# Parent  8618e4d900cc71082fbe7dc72af087937d64faf5
HTTP/2: close http2 connections initialized during graceful shutdown.

In some rare cases, a HTTP/2 connections can be initialized during a
graceful shutdown. Now close such an connection to avoid unexcepted
delays in the graceful shutdown.

diff -r 8618e4d900cc -r 70b6b6b69e6f src/http/v2/ngx_http_v2.c
--- a/src/http/v2/ngx_http_v2.c Tue Apr 16 18:27:50 2024 +0400
+++ b/src/http/v2/ngx_http_v2.c Mon May 06 11:10:08 2024 +0800
@@ -304,6 +304,11 @@
     c->idle = 1;
     ngx_reusable_connection(c, 0);

+    if (ngx_exiting) {
+        ngx_http_v2_finalize_connection(h2c, NGX_HTTP_V2_NO_ERROR);
+        return;
+    }
+
     if (c->buffer) {
         p = c->buffer->pos;
         end = c->buffer->last;