From abcbe5421990ddfd8ff87bd905bdc62c5675a6c8 Mon Sep 17 00:00:00 2001
From: Valentin Bartenev <vbart@nginx.com>
Date: Mon, 20 Jan 2014 20:56:49 +0400
Subject: [PATCH] SPDY: use ngx_queue_t to queue streams for post processing.

It simplifies the code and allows easy reuse the same queue pointer to store
streams in various queues with different requirements.  Future implementation
of SPDY/3.1 will take advantage of this quality.
---
 src/http/ngx_http_spdy.c               | 32 +++++++++++---------------
 src/http/ngx_http_spdy.h               |  6 +++--
 src/http/ngx_http_spdy_filter_module.c |  4 +---
 3 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/src/http/ngx_http_spdy.c b/src/http/ngx_http_spdy.c
index accfcb1d4..27c8aa196 100644
--- a/src/http/ngx_http_spdy.c
+++ b/src/http/ngx_http_spdy.c
@@ -302,6 +302,8 @@ ngx_http_spdy_init(ngx_event_t *rev)
         return;
     }
 
+    ngx_queue_init(&sc->posted);
+
     c->data = sc;
 
     rev->handler = ngx_http_spdy_read_handler;
@@ -405,8 +407,9 @@ static void
 ngx_http_spdy_write_handler(ngx_event_t *wev)
 {
     ngx_int_t                    rc;
+    ngx_queue_t                 *q;
     ngx_connection_t            *c;
-    ngx_http_spdy_stream_t      *stream, *s, *sn;
+    ngx_http_spdy_stream_t      *stream;
     ngx_http_spdy_connection_t  *sc;
 
     c = wev->data;
@@ -430,18 +433,13 @@ ngx_http_spdy_write_handler(ngx_event_t *wev)
         return;
     }
 
-    stream = NULL;
+    while (!ngx_queue_empty(&sc->posted)) {
+        q = ngx_queue_head(&sc->posted);
 
-    for (s = sc->last_stream; s; s = sn) {
-         sn = s->next;
-         s->next = stream;
-         stream = s;
-    }
+        ngx_queue_remove(q);
 
-    sc->last_stream = NULL;
+        stream = ngx_queue_data(q, ngx_http_spdy_stream_t, queue);
 
-    for ( /* void */ ; stream; stream = sn) {
-        sn = stream->next;
         stream->handled = 0;
 
         ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
@@ -2593,6 +2591,11 @@ ngx_http_spdy_close_stream(ngx_http_spdy_stream_t *stream, ngx_int_t rc)
                    "spdy close stream %ui, queued %ui, processing %ui",
                    stream->id, stream->queued, sc->processing);
 
+    if (stream->handled) {
+        stream->handled = 0;
+        ngx_queue_remove(&stream->queue);
+    }
+
     fc = stream->request->connection;
 
     if (stream->queued) {
@@ -2614,15 +2617,6 @@ ngx_http_spdy_close_stream(ngx_http_spdy_stream_t *stream, ngx_int_t rc)
         sc->stream = NULL;
     }
 
-    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);
 
diff --git a/src/http/ngx_http_spdy.h b/src/http/ngx_http_spdy.h
index 652b88f01..8caa5b0c4 100644
--- a/src/http/ngx_http_spdy.h
+++ b/src/http/ngx_http_spdy.h
@@ -96,7 +96,8 @@ struct ngx_http_spdy_connection_s {
     ngx_http_spdy_stream_t         **streams_index;
 
     ngx_http_spdy_out_frame_t       *last_out;
-    ngx_http_spdy_stream_t          *last_stream;
+
+    ngx_queue_t                      posted;
 
     ngx_http_spdy_stream_t          *stream;
 
@@ -116,7 +117,6 @@ struct ngx_http_spdy_stream_s {
     ngx_http_request_t              *request;
     ngx_http_spdy_connection_t      *connection;
     ngx_http_spdy_stream_t          *index;
-    ngx_http_spdy_stream_t          *next;
 
     ngx_uint_t                       header_buffers;
     ngx_uint_t                       queued;
@@ -125,6 +125,8 @@ struct ngx_http_spdy_stream_s {
     ngx_chain_t                     *free_data_headers;
     ngx_chain_t                     *free_bufs;
 
+    ngx_queue_t                      queue;
+
     unsigned                         priority:2;
     unsigned                         handled:1;
     unsigned                         blocked:1;
diff --git a/src/http/ngx_http_spdy_filter_module.c b/src/http/ngx_http_spdy_filter_module.c
index 6cf4aea42..0ec9028ce 100644
--- a/src/http/ngx_http_spdy_filter_module.c
+++ b/src/http/ngx_http_spdy_filter_module.c
@@ -1073,9 +1073,7 @@ ngx_http_spdy_handle_stream(ngx_http_spdy_connection_t *sc,
         wev->delayed = 0;
 
         stream->handled = 1;
-
-        stream->next = sc->last_stream;
-        sc->last_stream = stream;
+        ngx_queue_insert_tail(&sc->posted, &stream->queue);
     }
 }