Changeset 62955 in webkit

Timestamp:

Jul 9, 2010 8:26:16 AM (14 years ago)

Author:

commit-queue@webkit.org

Message:

2010-07-09 Sebastian Dröge <​sebastian.droege@collabora.co.uk>

Reviewed by Gustavo Noronha Silva.

Bug 41340 - [GStreamer] Subtle race condition during seeks
​https://bugs.webkit.org/show_bug.cgi?id=41340

• platform/graphics/gstreamer/WebKitWebSourceGStreamer.cpp: (webKitWebSrcStop): (webKitWebSrcNeedDataMainCb): (webKitWebSrcNeedDataCb): (webKitWebSrcEnoughDataMainCb): (webKitWebSrcEnoughDataCb): (webKitWebSrcSeekDataCb): (StreamingClient::didFinishLoading): Fix two subtle race conditions that can happen during seeks:
• The timeout callback could be called before the callback ID is assigned to the instance private data. This causes the ID to be set after the callback has finished and breaks all future processing.
• The source must not go EOS while a seek is pending because this confuses appsrc due to the different threads involved here.

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/gstreamer/WebKitWebSourceGStreamer.cpp (modified) (8 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2010-07-09  Sebastian Dröge  <sebastian.droege@collabora.co.uk>
+
+        Reviewed by Gustavo Noronha Silva.
+
+        Bug 41340 - [GStreamer] Subtle race condition during seeks
+        https://bugs.webkit.org/show_bug.cgi?id=41340
+
+        * platform/graphics/gstreamer/WebKitWebSourceGStreamer.cpp:
+        (webKitWebSrcStop):
+        (webKitWebSrcNeedDataMainCb):
+        (webKitWebSrcNeedDataCb):
+        (webKitWebSrcEnoughDataMainCb):
+        (webKitWebSrcEnoughDataCb):
+        (webKitWebSrcSeekDataCb):
+        (StreamingClient::didFinishLoading):
+        Fix two subtle race conditions that can happen during seeks:
+        - The timeout callback could be called before the callback ID is
+          assigned to the instance private data. This causes the ID to
+          be set after the callback has finished and breaks all future
+          processing.
+        - The source must not go EOS while a seek is pending because
+          this confuses appsrc due to the different threads involved here.
+
 2010-07-09  Simon Hausmann  <simon.hausmann@nokia.com>
 

trunk/WebCore/platform/graphics/gstreamer/WebKitWebSourceGStreamer.cpp

@@ -331 +331 @@
         priv->frame.release();
 
+    GST_OBJECT_LOCK(src);
     if (priv->needDataID)
         g_source_remove(priv->needDataID);
@@ -344 +345 @@
 
     priv->paused = FALSE;
+    GST_OBJECT_UNLOCK(src);
 
     g_free(priv->iradioName);
@@ -543 +545 @@
     // underlying network implementation here.
 
+    GST_OBJECT_LOCK(src);
     priv->paused = FALSE;
     priv->needDataID = 0;
+    GST_OBJECT_UNLOCK(src);
     return FALSE;
 }
@@ -554 +558 @@
 
     GST_DEBUG_OBJECT(src, "Need more data: %u", length);
-    if (priv->needDataID || !priv->paused)
+
+    GST_OBJECT_LOCK(src);
+    if (priv->needDataID || !priv->paused) {
+        GST_OBJECT_UNLOCK(src);
         return;
+    }
 
     priv->needDataID = g_timeout_add_full(G_PRIORITY_DEFAULT, 0, (GSourceFunc) webKitWebSrcNeedDataMainCb, gst_object_ref(src), (GDestroyNotify) gst_object_unref);
+    GST_OBJECT_UNLOCK(src);
 }
 
@@ -571 +580 @@
     // underlying network implementation here.
 
+    GST_OBJECT_LOCK(src);
     priv->paused = TRUE;
     priv->enoughDataID = 0;
+    GST_OBJECT_UNLOCK(src);
+
     return FALSE;
 }
@@ -582 +594 @@
 
     GST_DEBUG_OBJECT(src, "Have enough data");
-    if (priv->enoughDataID || priv->paused)
+
+    GST_OBJECT_LOCK(src);
+    if (priv->enoughDataID || priv->paused) {
+        GST_OBJECT_UNLOCK(src);
         return;
+    }
 
     priv->enoughDataID = g_timeout_add_full(G_PRIORITY_DEFAULT, 0, (GSourceFunc) webKitWebSrcEnoughDataMainCb, gst_object_ref(src), (GDestroyNotify) gst_object_unref);
+    GST_OBJECT_UNLOCK(src);
 }
 
@@ -612 +629 @@
     GST_DEBUG_OBJECT(src, "Doing range-request seek");
     priv->requestedOffset = offset;
+
+    GST_OBJECT_LOCK(src);
     if (priv->seekID)
         g_source_remove(priv->seekID);
     priv->seekID = g_timeout_add_full(G_PRIORITY_DEFAULT, 0, (GSourceFunc) webKitWebSrcSeekMainCb, gst_object_ref(src), (GDestroyNotify) gst_object_unref);
+    GST_OBJECT_UNLOCK(src);
     
     return TRUE;
@@ -744 +764 @@
 void StreamingClient::didFinishLoading(ResourceHandle*)
 {
+    WebKitWebSrcPrivate* priv = m_src->priv;
+
     GST_DEBUG_OBJECT(m_src, "Have EOS");
-    gst_app_src_end_of_stream(m_src->priv->appsrc);
+
+    if (!priv->seekID)
+        gst_app_src_end_of_stream(m_src->priv->appsrc);
 }