queue2: download mode; prevent range corruption due to race

Current range was being updated in the thread performing seek, but as
no locks were kept for a short section, data flow could resume before
current range updated, so data for the new range would be accepted as
from the previous range.

Rather, range should be updated in serialized manner based on
newsegment event.

1 files changed, 9 insertions, 5 deletions

diff --git a/plugins/elements/gstqueue2.c b/plugins/elements/gstqueue2.c
index 83af4b9bd5..8f595a22ca 100644
--- a/plugins/elements/gstqueue2.c
+++ b/plugins/elements/gstqueue2.c
@@ -241,12 +241,15 @@ static gboolean gst_queue2_sink_activate_push (GstPad * pad, gboolean active);
 static GstStateChangeReturn gst_queue2_change_state (GstElement * element,
     GstStateChange transition);
 
 static gboolean gst_queue2_is_empty (GstQueue2 * queue);
 static gboolean gst_queue2_is_filled (GstQueue2 * queue);
 
+static void update_cur_level (GstQueue2 * queue, GstQueue2Range * range);
+
+
 /* static guint gst_queue2_signals[LAST_SIGNAL] = { 0 }; */
 
 static void
 gst_queue2_base_init (gpointer g_class)
 {
   GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
@@ -645,12 +648,18 @@ apply_segment (GstQueue2 * queue, GstEvent * event, GstSegment * segment)
       "received NEWSEGMENT update %d, rate %lf, applied rate %lf, "
       "format %d, "
       "%" G_GINT64_FORMAT " -- %" G_GINT64_FORMAT ", time %"
       G_GINT64_FORMAT, update, rate, arate, format, start, stop, time);
 
   if (format == GST_FORMAT_BYTES) {
+    if (QUEUE_IS_USING_TEMP_FILE (queue)) {
+      /* start is where we'll be getting from and as such writing next */
+      queue->current = add_range (queue, start);
+      /* update the stats for this range */
+      update_cur_level (queue, queue->current);
+    }
   }
 
   /* now configure the values, we use these to track timestamps on the
    * sinkpad. */
   if (format != GST_FORMAT_TIME) {
     /* non-time format, pretent the current time segment is closed with a
@@ -1009,17 +1018,12 @@ perform_seek_to_offset (GstQueue2 * queue, guint64 offset)
       GST_SEEK_TYPE_NONE, -1);
 
   GST_QUEUE2_MUTEX_UNLOCK (queue);
   res = gst_pad_push_event (queue->sinkpad, event);
   GST_QUEUE2_MUTEX_LOCK (queue);
 
-  if (res) {
-    queue->current = add_range (queue, offset);
-    /* update the stats for this range */
-    update_cur_level (queue, queue->current);
-  }
   return res;
 }
 
 /* see if there is enough data in the file to read a full buffer */
 static gboolean
 gst_queue2_have_data (GstQueue2 * queue, guint64 offset, guint length)