QEventDispatcherWin32: redesign event notifiers activation

The previous implementation multiplexed callback-based event
notification into a single proxy event (cf. 85403d0af), which was
in turn object-waited for (this was the case since the beginning
of public qt history). It makes more sense to multiplex into a
posted message, because that also works with foreign event loops
that do not know anything about our event objects.

Task-number: QTBUG-64443
Change-Id: I97945ac8b5d7c8582701077134c0aef4f3b5a18f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/corelib/kernel/qeventdispatcher_win_p.h b/src/corelib/kernel/qeventdispatcher_win_p.h
index dbb30ab568..078329c43c 100644
--- a/src/corelib/kernel/qeventdispatcher_win_p.h
+++ b/src/corelib/kernel/qeventdispatcher_win_p.h
@@ -54,6 +54,7 @@
 #include "QtCore/qabstracteventdispatcher.h"
 #include "QtCore/qt_windows.h"
 #include "QtCore/qhash.h"
+#include "QtCore/qatomic.h"
 
 #include "qabstracteventdispatcher_p.h"
 
@@ -193,8 +194,9 @@ public:
     bool closingDown = false;
 
     bool winEventNotifierListModified = false;
-    HANDLE winEventNotifierActivatedEvent;
+    QAtomicInt activateEventNotifiersPosted;
     QList<QWinEventNotifier *> winEventNotifierList;
+    void postActivateEventNotifiers();
     void activateEventNotifier(QWinEventNotifier * wen);
 
     QList<MSG> queuedUserInputEvents;