details: http://hg.nginx.org/nginx/rev/916cb6d28f6a
branches:
changeset: 5493:916cb6d28f6a
user: Valentin Bartenev <vbart@nginx.com>
date: Thu Dec 26 17:03:16 2013 +0400
description:
SPDY: fixed possible request hang.

Processing events from upstream connection can result in sending queued frames
from other streams. In this case such streams were not added to handling queue
and properly handled.

A global per connection flag was replaced by a per stream flag that indicates
currently sending stream while all other streams can be added to handling
queue.

diffstat:

src/http/ngx_http_spdy.c | 17 +++++++++++++----
src/http/ngx_http_spdy.h | 3 ++-
src/http/ngx_http_spdy_filter_module.c | 14 ++++++++------
3 files changed, 23 insertions(+), 11 deletions(-)

diffs (110 lines):

diff -r 5c52ff68f380 -r 916cb6d28f6a src/http/ngx_http_spdy.c
--- a/src/http/ngx_http_spdy.c Mon Dec 23 18:12:03 2013 +0400
+++ b/src/http/ngx_http_spdy.c Thu Dec 26 17:03:16 2013 +0400
@@ -411,7 +411,7 @@ ngx_http_spdy_write_handler(ngx_event_t

ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "spdy write handler");

- sc->blocked = 2;
+ sc->blocked = 1;

rc = ngx_http_spdy_send_output_queue(sc);

@@ -430,8 +430,6 @@ ngx_http_spdy_write_handler(ngx_event_t

sc->last_stream = NULL;

- sc->blocked = 1;
-
for ( /* void */ ; stream; stream = sn) {
sn = stream->next;
stream->handled = 0;
@@ -2658,6 +2656,15 @@ ngx_http_spdy_close_stream(ngx_http_spdy
}
}

+ if (stream->handled) {
+ for (s = sc->last_stream; s; s = s->next) {
+ if (s->next == stream) {
+ s->next = stream->next;
+ break;
+ }
+ }
+ }
+
sscf = ngx_http_get_module_srv_conf(sc->http_connection->conf_ctx,
ngx_http_spdy_module);

@@ -2847,9 +2854,11 @@ ngx_http_spdy_finalize_connection(ngx_ht
stream = sc->streams_index[i];

while (stream) {
+ stream->handled = 0;
+
r = stream->request;
-
fc = r->connection;
+
fc->error = 1;

if (stream->waiting) {
diff -r 5c52ff68f380 -r 916cb6d28f6a src/http/ngx_http_spdy.h
--- a/src/http/ngx_http_spdy.h Mon Dec 23 18:12:03 2013 +0400
+++ b/src/http/ngx_http_spdy.h Thu Dec 26 17:03:16 2013 +0400
@@ -106,7 +106,7 @@ struct ngx_http_spdy_connection_s {

ngx_uint_t last_sid;

- unsigned blocked:2;
+ unsigned blocked:1;
unsigned waiting:1; /* FIXME better name */
};

@@ -125,6 +125,7 @@ struct ngx_http_spdy_stream_s {

unsigned priority:2;
unsigned handled:1;
+ unsigned blocked:1;
unsigned in_closed:1;
unsigned out_closed:1;
unsigned skip_data:2;
diff -r 5c52ff68f380 -r 916cb6d28f6a src/http/ngx_http_spdy_filter_module.c
--- a/src/http/ngx_http_spdy_filter_module.c Mon Dec 23 18:12:03 2013 +0400
+++ b/src/http/ngx_http_spdy_filter_module.c Thu Dec 26 17:03:16 2013 +0400
@@ -795,11 +795,15 @@ ngx_http_spdy_filter_get_data_frame(ngx_
static ngx_inline ngx_int_t
ngx_http_spdy_filter_send(ngx_connection_t *fc, ngx_http_spdy_stream_t *stream)
{
+ stream->blocked = 1;
+
if (ngx_http_spdy_send_output_queue(stream->connection) == NGX_ERROR) {
fc->error = 1;
return NGX_ERROR;
}

+ stream->blocked = 0;
+
if (stream->waiting) {
fc->buffered |= NGX_SPDY_WRITE_BUFFERED;
fc->write->delayed = 1;
@@ -946,16 +950,14 @@ ngx_http_spdy_handle_stream(ngx_http_spd

fc->write->delayed = 0;

- if (stream->handled) {
+ if (stream->handled || stream->blocked) {
return;
}

- if (sc->blocked == 2) {
- stream->handled = 1;
+ stream->handled = 1;

- stream->next = sc->last_stream;
- sc->last_stream = stream;
- }
+ stream->next = sc->last_stream;
+ sc->last_stream = stream;
}



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