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.

diff --git a/src/http/ngx_http_spdy.c b/src/http/ngx_http_spdy.c
index 2346ad7a1c8aaf912c163e19ba19a764cf382795..9a3550ad18a4b7aac91f1ca73bee2d12f161e12e 100644 (file)
--- a/src/http/ngx_http_spdy.c
+++ b/src/http/ngx_http_spdy.c
@@ -411,7 +411,7 @@ ngx_http_spdy_write_handler(ngx_event_t *wev)
 
     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 *wev)
 
     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_stream_t *stream, ngx_int_t rc)
         }
     }
 
+    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_http_spdy_connection_t *sc,
         stream = sc->streams_index[i];
 
         while (stream) {
-            r = stream->request;
+            stream->handled = 0;
 
+            r = stream->request;
             fc = r->connection;
+
             fc->error = 1;
 
             if (stream->waiting) {

diff --git a/src/http/ngx_http_spdy.h b/src/http/ngx_http_spdy.h
index c47243fb0134415030fccf0293f2b9f42f20aa1e..c011a3d6fa642b8e85ba4fc94a894b7cc2408d97 100644 (file)
--- a/src/http/ngx_http_spdy.h
+++ b/src/http/ngx_http_spdy.h
@@ -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 --git a/src/http/ngx_http_spdy_filter_module.c b/src/http/ngx_http_spdy_filter_module.c
index 4497e8b16037d570893a55766d0ba046367c2c79..c6926b20bd74d82fdf85c8fd69f0e4ee7821979e 100644 (file)
--- a/src/http/ngx_http_spdy_filter_module.c
+++ b/src/http/ngx_http_spdy_filter_module.c
@@ -795,11 +795,15 @@ ngx_http_spdy_filter_get_data_frame(ngx_http_spdy_stream_t *stream,
 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_spdy_connection_t *sc,
 
     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;
 }