Changeset 247415 in webkit

Timestamp:

Jul 13, 2019 4:07:41 AM (5 years ago)

Author:

Chris Dumez

Message:

Fix non thread-safe usage of makeWeakPtr() in MediaPlayerPrivateAVFoundation
​https://bugs.webkit.org/show_bug.cgi?id=199777

Reviewed by Eric Carlson.

The code was calling makeWeakPtr() on a main-thread object, from a background thread.
This is not thread safe. To address the issue, this patches creates the WeakPtr ahead
of time, on the main thread.

• platform/graphics/avfoundation/MediaPlayerPrivateAVFoundation.cpp:

(WebCore::MediaPlayerPrivateAVFoundation::MediaPlayerPrivateAVFoundation):
(WebCore::MediaPlayerPrivateAVFoundation::scheduleMainThreadNotification):
(WebCore::MediaPlayerPrivateAVFoundation::dispatchNotification):

• platform/graphics/avfoundation/MediaPlayerPrivateAVFoundation.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/avfoundation/MediaPlayerPrivateAVFoundation.cpp (modified) (3 diffs)
• platform/graphics/avfoundation/MediaPlayerPrivateAVFoundation.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-07-13  Chris Dumez  <cdumez@apple.com>
+
+        Fix non thread-safe usage of makeWeakPtr() in MediaPlayerPrivateAVFoundation
+        https://bugs.webkit.org/show_bug.cgi?id=199777
+
+        Reviewed by Eric Carlson.
+
+        The code was calling makeWeakPtr() on a main-thread object, from a background thread.
+        This is not thread safe. To address the issue, this patches creates the WeakPtr ahead
+        of time, on the main thread.
+
+        * platform/graphics/avfoundation/MediaPlayerPrivateAVFoundation.cpp:
+        (WebCore::MediaPlayerPrivateAVFoundation::MediaPlayerPrivateAVFoundation):
+        (WebCore::MediaPlayerPrivateAVFoundation::scheduleMainThreadNotification):
+        (WebCore::MediaPlayerPrivateAVFoundation::dispatchNotification):
+        * platform/graphics/avfoundation/MediaPlayerPrivateAVFoundation.h:
+
 2019-07-12  Thibault Saunier  <tsaunier@igalia.com>
 

trunk/Source/WebCore/platform/graphics/avfoundation/MediaPlayerPrivateAVFoundation.cpp

@@ -56 +56 @@
 
 MediaPlayerPrivateAVFoundation::MediaPlayerPrivateAVFoundation(MediaPlayer* player)
-    : m_player(player)
+    : m_weakThis(makeWeakPtr(*this))
+    , m_player(player)
     , m_queuedNotifications()
     , m_queueMutex()
@@ -775 +776 @@
         m_mainThreadCallPending = true;
 
-        callOnMainThread([weakThis = makeWeakPtr(*this)] {
+        callOnMainThread([weakThis = m_weakThis] {
             if (!weakThis)
                 return;
@@ -808 +809 @@
         
         if (!m_queuedNotifications.isEmpty() && !m_mainThreadCallPending) {
-            callOnMainThread([weakThis = makeWeakPtr(*this)] {
+            callOnMainThread([weakThis = m_weakThis] {
                 if (!weakThis)
                     return;

trunk/Source/WebCore/platform/graphics/avfoundation/MediaPlayerPrivateAVFoundation.h

@@ -328 +328 @@
 
 private:
+    WeakPtr<MediaPlayerPrivateAVFoundation> m_weakThis;
     MediaPlayer* m_player;