[nginx] HTTP/2: introduced separate handler to retry stream close.

[Maxim Dounin]

details:   https://hg.nginx.org/nginx/rev/8e64e11aaca0
branches:  
changeset: 7611:8e64e11aaca0
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Mon Dec 23 21:25:21 2019 +0300
description:
HTTP/2: introduced separate handler to retry stream close.

When ngx_http_v2_close_stream_handler() is used to retry stream close
after queued frames are sent, client timeouts on the stream can be
logged multiple times and/or in addition to already happened errors.
To resolve this, separate ngx_http_v2_retry_close_stream_handler()
was introduced, which does not try to log timeouts.

diffstat:

 src/http/v2/ngx_http_v2.c |  21 +++++++++++++++++++--
 1 files changed, 19 insertions(+), 2 deletions(-)

diffs (45 lines):

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
@@ -178,6 +178,7 @@ static void ngx_http_v2_read_client_requ
 static ngx_int_t ngx_http_v2_terminate_stream(ngx_http_v2_connection_t *h2c,
     ngx_http_v2_stream_t *stream, ngx_uint_t status);
 static void ngx_http_v2_close_stream_handler(ngx_event_t *ev);
+static void ngx_http_v2_retry_close_stream_handler(ngx_event_t *ev);
 static void ngx_http_v2_handle_connection_handler(ngx_event_t *rev);
 static void ngx_http_v2_idle_handler(ngx_event_t *rev);
 static void ngx_http_v2_finalize_connection(ngx_http_v2_connection_t *h2c,
@@ -4289,8 +4290,8 @@ ngx_http_v2_close_stream(ngx_http_v2_str
 
     if (stream->queued) {
         fc->error = 1;
-        fc->write->handler = ngx_http_v2_close_stream_handler;
-        fc->read->handler = ngx_http_v2_close_stream_handler;
+        fc->write->handler = ngx_http_v2_retry_close_stream_handler;
+        fc->read->handler = ngx_http_v2_retry_close_stream_handler;
         return;
     }
 
@@ -4413,6 +4414,22 @@ ngx_http_v2_close_stream_handler(ngx_eve
 
 
 static void
+ngx_http_v2_retry_close_stream_handler(ngx_event_t *ev)
+{
+    ngx_connection_t    *fc;
+    ngx_http_request_t  *r;
+
+    fc = ev->data;
+    r = fc->data;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, fc->log, 0,
+                   "http2 retry close stream handler");
+
+    ngx_http_v2_close_stream(r->stream, 0);
+}
+
+
+static void
 ngx_http_v2_handle_connection_handler(ngx_event_t *rev)
 {
     ngx_connection_t          *c;