Make QBasicMutex be exclusively non-recursive

Dispatch to the recursive mutex functions from QMutex::lock, tryLock
and unlock.

This has the benefit that those using QBasicMutex will not go through
the testing for recursive mutexes. It simplifies a little the code for
those users.

For the users of QMutex, the code required to perform a lock does not
appear to change.

Change-Id: I0ca9965e012b283c30f1fab8e9f6d9b3288c2247
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/corelib/thread/qmutex.h b/src/corelib/thread/qmutex.h
index 5d4d6969f5..dd718c4796 100644
--- a/src/corelib/thread/qmutex.h
+++ b/src/corelib/thread/qmutex.h
@@ -71,7 +71,7 @@ public:
 
     inline void unlock() Q_DECL_NOTHROW {
         Q_ASSERT(d_ptr.load()); //mutex must be locked
-        if (!d_ptr.testAndSetRelease(dummyLocked(), 0))
+        if (!fastTryUnlock())
             unlockInternal();
     }
 
@@ -85,6 +85,10 @@ private:
     inline bool fastTryLock() Q_DECL_NOTHROW {
         return d_ptr.testAndSetAcquire(0, dummyLocked());
     }
+    inline bool fastTryUnlock() Q_DECL_NOTHROW {
+        return d_ptr.testAndSetRelease(dummyLocked(), 0);
+    }
+
     bool lockInternal(int timeout = -1) QT_MUTEX_LOCK_NOEXCEPT;
     void unlockInternal() Q_DECL_NOTHROW;