Fix data race on QLoggingCategory when using qDebug from multiple threads

setEnabled() would race with isEnabled()/isDebugEnabled()/etc.

Change-Id: I2004cba81d5417a634b97f5c2f98d3a4ab71770d
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/corelib/arch/qatomic_bootstrap.h b/src/corelib/arch/qatomic_bootstrap.h
index 7f17387c9c..0d6843a3e5 100644
--- a/src/corelib/arch/qatomic_bootstrap.h
+++ b/src/corelib/arch/qatomic_bootstrap.h
@@ -67,8 +67,10 @@ template <typename T> struct QAtomicOps: QGenericAtomicOps<QAtomicOps<T> >
         return --_q_value != 0;
     }
 
-    static bool testAndSetRelaxed(T &_q_value, T expectedValue, T newValue) Q_DECL_NOTHROW
+    static bool testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue = 0) Q_DECL_NOTHROW
     {
+        if (currentValue)
+            *currentValue = _q_value;
         if (_q_value == expectedValue) {
             _q_value = newValue;
             return true;