Merge r226947 - [GStreamer] Don't wait for draw condition variable wh…

…en shutting down. https://bugs.webkit.org/show_bug.cgi?id=180978 Patch by Sebastian Dröge <sebastian@centricular.com> on 2018-01-15 Reviewed by Carlos Garcia Campos. * platform/graphics/gstreamer/MediaPlayerPrivateGStreamerBase.cpp: (WebCore::MediaPlayerPrivateGStreamerBase::triggerRepaint): (WebCore::MediaPlayerPrivateGStreamerBase::cancelRepaint): * platform/graphics/gstreamer/MediaPlayerPrivateGStreamerBase.h: By also waiting for the draw condition variable while shutting down, it is possible that the GStreamer video sink is waiting for the main thread to actually render the current frame, while at the same time the main thread is waiting for the GStreamer video sink to shut down, resulting in a deadlock.
WebKit · Jan 24, 2018 · 15f7fa8 · 15f7fa8
1 parent eaba652
commit 15f7fa8
Show file tree

Hide file tree

Showing 3 changed files with 27 additions and 2 deletions.
diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
@@ -1,3 +1,20 @@
+2018-01-15  Sebastian Dröge  <sebastian@centricular.com>
+
+        [GStreamer] Don't wait for draw condition variable when shutting down.
+        https://bugs.webkit.org/show_bug.cgi?id=180978
+
+        Reviewed by Carlos Garcia Campos.
+
+        * platform/graphics/gstreamer/MediaPlayerPrivateGStreamerBase.cpp:
+        (WebCore::MediaPlayerPrivateGStreamerBase::triggerRepaint):
+        (WebCore::MediaPlayerPrivateGStreamerBase::cancelRepaint):
+        * platform/graphics/gstreamer/MediaPlayerPrivateGStreamerBase.h:
+        By also waiting for the draw condition variable while shutting down,
+        it is possible that the GStreamer video sink is waiting for the main
+        thread to actually render the current frame, while at the same time
+        the main thread is waiting for the GStreamer video sink to shut down,
+        resulting in a deadlock.
+
 2017-10-06  Enrique Ocaña González  <eocanha@igalia.com>
 
         [MSE][GStreamer] Seek on youtube.com/tv fails after r217185

diff --git a/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamerBase.cpp b/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamerBase.cpp
@@ -661,6 +661,8 @@ void MediaPlayerPrivateGStreamerBase::triggerRepaint(GstSample* sample)
 
     if (!m_renderingCanBeAccelerated) {
         LockHolder locker(m_drawMutex);
+        if (m_drawCancelled)
+            return;
         m_drawTimer.startOneShot(0_s);
         m_drawCondition.wait(m_drawMutex);
         return;
@@ -672,6 +674,8 @@ void MediaPlayerPrivateGStreamerBase::triggerRepaint(GstSample* sample)
 #else
     {
         LockHolder lock(m_drawMutex);
+        if (m_drawCancelled)
+            return;
         if (!m_platformLayerProxy->scheduleUpdateOnCompositorThread([this] { this->pushTextureToCompositor(); }))
             return;
         m_drawCondition.wait(m_drawMutex);
@@ -687,11 +691,14 @@ void MediaPlayerPrivateGStreamerBase::repaintCallback(MediaPlayerPrivateGStreame
 
 void MediaPlayerPrivateGStreamerBase::cancelRepaint()
 {
+    LockHolder locker(m_drawMutex);
+
     if (!m_renderingCanBeAccelerated) {
         m_drawTimer.stop();
-        LockHolder locker(m_drawMutex);
-        m_drawCondition.notifyOne();
     }
+
+    m_drawCancelled = true;
+    m_drawCondition.notifyOne();
 }
 
 void MediaPlayerPrivateGStreamerBase::repaintCancelledCallback(MediaPlayerPrivateGStreamerBase* player)

diff --git a/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamerBase.h b/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamerBase.h
@@ -205,6 +205,7 @@ class MediaPlayerPrivateGStreamerBase : public MediaPlayerPrivateInterface
 
     Condition m_drawCondition;
     Lock m_drawMutex;
+    bool m_drawCancelled { false };
     RunLoop::Timer<MediaPlayerPrivateGStreamerBase> m_drawTimer;
 
 #if USE(TEXTURE_MAPPER_GL)