Title: [114028] trunk/Source/WTF
- Revision
- 114028
- Author
- [email protected]
- Date
- 2012-04-12 13:35:18 -0700 (Thu, 12 Apr 2012)
Log Message
ThreadingWin: Mutex::unlock() can be "over-unlocked".
https://bugs.webkit.org/show_bug.cgi?id=83725
Reviewed by David Levin.
In order to support the behavior of pthread_mutex_trylock(), the Windows Mutex class includes
a recursion counter which is incremented in Mutex::lock(), decremented in Mutex::unlock(),
and checked in Mutex::tryLock(). If the mutex is "over-unlocked", the counter wraps around to
MAX_INT, and subsequent calls to Mutex::trylock() will fail. Raise an ASSERT in this situation
so the "over-unlock" will be caught.
* wtf/ThreadingWin.cpp:
(WTF::Mutex::unlock): ASSERT if unlocking a non-locked mutex.
Modified Paths
Diff
Modified: trunk/Source/WTF/ChangeLog (114027 => 114028)
--- trunk/Source/WTF/ChangeLog 2012-04-12 20:31:51 UTC (rev 114027)
+++ trunk/Source/WTF/ChangeLog 2012-04-12 20:35:18 UTC (rev 114028)
@@ -1,3 +1,19 @@
+2012-04-12 Jer Noble <[email protected]>
+
+ ThreadingWin: Mutex::unlock() can be "over-unlocked".
+ https://bugs.webkit.org/show_bug.cgi?id=83725
+
+ Reviewed by David Levin.
+
+ In order to support the behavior of pthread_mutex_trylock(), the Windows Mutex class includes
+ a recursion counter which is incremented in Mutex::lock(), decremented in Mutex::unlock(),
+ and checked in Mutex::tryLock(). If the mutex is "over-unlocked", the counter wraps around to
+ MAX_INT, and subsequent calls to Mutex::trylock() will fail. Raise an ASSERT in this situation
+ so the "over-unlock" will be caught.
+
+ * wtf/ThreadingWin.cpp:
+ (WTF::Mutex::unlock): ASSERT if unlocking a non-locked mutex.
+
2012-04-10 Mark Rowe <[email protected]>
<rdar://problem/10583749> WebKit2 should log to both ASL and stderr
Modified: trunk/Source/WTF/wtf/ThreadingWin.cpp (114027 => 114028)
--- trunk/Source/WTF/wtf/ThreadingWin.cpp 2012-04-12 20:31:51 UTC (rev 114027)
+++ trunk/Source/WTF/wtf/ThreadingWin.cpp 2012-04-12 20:35:18 UTC (rev 114028)
@@ -335,6 +335,7 @@
void Mutex::unlock()
{
+ ASSERT(m_mutex.m_recursionCount);
--m_mutex.m_recursionCount;
LeaveCriticalSection(&m_mutex.m_internalMutex);
}
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