Title: [110699] trunk/Source/WebCore
- Revision
- 110699
- Author
- abe...@webkit.org
- Date
- 2012-03-14 08:02:14 -0700 (Wed, 14 Mar 2012)
Log Message
[Qt] RunLoopQt is missing reentrancy guards
https://bugs.webkit.org/show_bug.cgi?id=80982
Patch by Simon Hausmann <simon.hausm...@nokia.com> on 2012-03-14
Reviewed by Tor Arne Vestbø.
Avoid recursive calls to RunLoop::performWork() with a simple
counting mechanism, to avoid out-of-order message dispatching.
* platform/qt/RunLoopQt.cpp:
(WebCore::RunLoop::TimerObject::TimerObject):
(WebCore::RunLoop::TimerObject::performWork):
(RunLoop::TimerObject):
Modified Paths
Diff
Modified: trunk/Source/WebCore/ChangeLog (110698 => 110699)
--- trunk/Source/WebCore/ChangeLog 2012-03-14 14:41:26 UTC (rev 110698)
+++ trunk/Source/WebCore/ChangeLog 2012-03-14 15:02:14 UTC (rev 110699)
@@ -1,3 +1,18 @@
+2012-03-14 Simon Hausmann <simon.hausm...@nokia.com>
+
+ [Qt] RunLoopQt is missing reentrancy guards
+ https://bugs.webkit.org/show_bug.cgi?id=80982
+
+ Reviewed by Tor Arne Vestbø.
+
+ Avoid recursive calls to RunLoop::performWork() with a simple
+ counting mechanism, to avoid out-of-order message dispatching.
+
+ * platform/qt/RunLoopQt.cpp:
+ (WebCore::RunLoop::TimerObject::TimerObject):
+ (WebCore::RunLoop::TimerObject::performWork):
+ (RunLoop::TimerObject):
+
2012-03-14 Ilya Tikhonovsky <loi...@chromium.org>
Web Inspector: small improvement for HeapSnapshot performance ~12%.
Modified: trunk/Source/WebCore/platform/qt/RunLoopQt.cpp (110698 => 110699)
--- trunk/Source/WebCore/platform/qt/RunLoopQt.cpp 2012-03-14 14:41:26 UTC (rev 110698)
+++ trunk/Source/WebCore/platform/qt/RunLoopQt.cpp 2012-03-14 15:02:14 UTC (rev 110699)
@@ -39,13 +39,30 @@
class RunLoop::TimerObject : public QObject {
Q_OBJECT
public:
- TimerObject(RunLoop* runLoop) : m_runLoop(runLoop)
+ TimerObject(RunLoop* runLoop)
+ : m_runLoop(runLoop)
+ , m_pendingPerformWorkInvocations(0)
{
int methodIndex = metaObject()->indexOfMethod("performWork()");
m_method = metaObject()->method(methodIndex);
}
- Q_SLOT void performWork() { m_runLoop->performWork(); }
+ Q_SLOT void performWork() {
+ // It may happen that a secondary thread adds more method invocations via
+ // RunLoop::dispatch(), which will schedule a call to this function. If during
+ // performWork() event loop messages get processed, it may happen that this
+ // function is called again. In this case we should protected ourselves against
+ // recursive - and thus out-of-order - message dispatching and instead perform
+ // the work serially.
+ m_pendingPerformWorkInvocations++;
+ if (m_pendingPerformWorkInvocations > 1)
+ return;
+
+ while (m_pendingPerformWorkInvocations) {
+ m_runLoop->performWork();
+ m_pendingPerformWorkInvocations--;
+ }
+ }
inline void wakeUp() { m_method.invoke(this, Qt::QueuedConnection); }
protected:
@@ -57,6 +74,7 @@
private:
RunLoop* m_runLoop;
QMetaMethod m_method;
+ int m_pendingPerformWorkInvocations;
};
static QEventLoop* currentEventLoop;
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