# HG changeset patch
# User Valentin Bartenev <vbart@nginx.com>
# Date 1390352299 -14400
# Node ID d5de6c25b7599f399904c508d13bb763dc81a5ae
# Parent  f3f7b72ca6e957769c1726fe70972f94c101ddc5
SPDY: use frame->next pointer to chain free frames.

There is no need in separate "free" pointer and like it is for ngx_chain_t
the "next" pointer can be used.  But after this change successfully handled
frame should not be accessed, so the frame handling cycle was improved to
store pointer to the next frame before processing.

Also worth noting that initializing "free" pointer to NULL in the original
code was surplus.

diff --git a/src/http/ngx_http_spdy.c b/src/http/ngx_http_spdy.c
--- a/src/http/ngx_http_spdy.c
+++ b/src/http/ngx_http_spdy.c
@@ -527,7 +527,9 @@ ngx_http_spdy_send_output_queue(ngx_http
         }
     }
 
-    for ( /* void */ ; out; out = out->next) {
+    for ( /* void */ ; out; out = fn) {
+        fn = out->next;
+
         if (out->handler(sc, out) != NGX_OK) {
             out->blocked = 1;
             out->priority = NGX_SPDY_HIGHEST_PRIORITY;
@@ -1644,7 +1646,7 @@ ngx_http_spdy_get_ctl_frame(ngx_http_spd
     frame = sc->free_ctl_frames;
 
     if (frame) {
-        sc->free_ctl_frames = frame->free;
+        sc->free_ctl_frames = frame->next;
 
         cl = frame->first;
         cl->buf->pos = cl->buf->start;
@@ -1674,8 +1676,6 @@ ngx_http_spdy_get_ctl_frame(ngx_http_spd
         frame->stream = NULL;
     }
 
-    frame->free = NULL;
-
 #if (NGX_DEBUG)
     if (size > NGX_SPDY_CTL_FRAME_BUFFER_SIZE - NGX_SPDY_FRAME_HEADER_SIZE) {
         ngx_log_error(NGX_LOG_ALERT, sc->pool->log, 0,
@@ -1705,7 +1705,7 @@ ngx_http_spdy_ctl_frame_handler(ngx_http
         return NGX_AGAIN;
     }
 
-    frame->free = sc->free_ctl_frames;
+    frame->next = sc->free_ctl_frames;
     sc->free_ctl_frames = frame;
 
     return NGX_OK;
diff --git a/src/http/ngx_http_spdy.h b/src/http/ngx_http_spdy.h
--- a/src/http/ngx_http_spdy.h
+++ b/src/http/ngx_http_spdy.h
@@ -141,8 +141,6 @@ struct ngx_http_spdy_out_frame_s {
     ngx_int_t                      (*handler)(ngx_http_spdy_connection_t *sc,
                                         ngx_http_spdy_out_frame_t *frame);
 
-    ngx_http_spdy_out_frame_t       *free;
-
     ngx_http_spdy_stream_t          *stream;
     size_t                           size;
 
diff --git a/src/http/ngx_http_spdy_filter_module.c b/src/http/ngx_http_spdy_filter_module.c
--- a/src/http/ngx_http_spdy_filter_module.c
+++ b/src/http/ngx_http_spdy_filter_module.c
@@ -587,7 +587,6 @@ ngx_http_spdy_header_filter(ngx_http_req
     frame->first = cl;
     frame->last = cl;
     frame->handler = ngx_http_spdy_syn_frame_handler;
-    frame->free = NULL;
     frame->stream = stream;
     frame->size = len;
     frame->priority = stream->priority;
@@ -821,7 +820,7 @@ ngx_http_spdy_filter_get_data_frame(ngx_
     frame = stream->free_frames;
 
     if (frame) {
-        stream->free_frames = frame->free;
+        stream->free_frames = frame->next;
 
     } else {
         frame = ngx_palloc(stream->request->pool,
@@ -881,7 +880,6 @@ ngx_http_spdy_filter_get_data_frame(ngx_
     frame->first = first;
     frame->last = last;
     frame->handler = ngx_http_spdy_data_frame_handler;
-    frame->free = NULL;
     frame->stream = stream;
     frame->size = NGX_SPDY_FRAME_HEADER_SIZE + len;
     frame->priority = stream->priority;
@@ -1051,7 +1049,7 @@ ngx_http_spdy_handle_frame(ngx_http_spdy
         stream->out_closed = 1;
     }
 
-    frame->free = stream->free_frames;
+    frame->next = stream->free_frames;
     stream->free_frames = frame;
 
     stream->queued--;