[nginx] SPDY: send output queue after processing of read event.

[Valentin Bartenev]

details:   http://hg.nginx.org/nginx/rev/a336cbc3dd44
branches:  
changeset: 5520:a336cbc3dd44
user:      Valentin Bartenev <vbart at nginx.com>
date:      Wed Jan 15 17:16:38 2014 +0400
description:
SPDY: send output queue after processing of read event.

During the processing of input some control frames can be added to the queue.
And if there were no writing streams at the moment, these control frames might
be left unsent for a long time (or even forever).

This long delay is especially critical for PING replies since a client can
consider connection as broken and then resend exactly the same request over
a new connection, which is not safe in case of non-idempotent HTTP methods.

diffstat:

 src/http/ngx_http_spdy.c |  5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diffs (15 lines):

diff -r 22c249dac7c1 -r a336cbc3dd44 src/http/ngx_http_spdy.c
--- a/src/http/ngx_http_spdy.c	Wed Jan 15 17:16:38 2014 +0400
+++ b/src/http/ngx_http_spdy.c	Wed Jan 15 17:16:38 2014 +0400
@@ -378,6 +378,11 @@ ngx_http_spdy_read_handler(ngx_event_t *
         return;
     }
 
+    if (sc->last_out && ngx_http_spdy_send_output_queue(sc) == NGX_ERROR) {
+        ngx_http_spdy_finalize_connection(sc, NGX_HTTP_CLIENT_CLOSED_REQUEST);
+        return;
+    }
+
     sc->blocked = 0;
 
     if (sc->processing) {