Simplify the safeguarding logic in notify()

The logic in notify() was doing quite a bit more work than
it needed to. By inserting a dummy node after the current one instead of
replacing it, we can avoid half of the data shuffling that has been
happening and also don't need a back pointer when executing the
notification.

Also avoid calling a semi expensive destructor of QPropertyObserver.

Reduces the overhead of notify() by ~30%.

Pick-to: dev 6.0.0
Change-Id: I7ce16bcf9cd9c4368c18bf875fc959223452fd4f
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 0 insertions, 7 deletions

diff --git a/src/corelib/kernel/qproperty_p.h b/src/corelib/kernel/qproperty_p.h
index 6bc65e986d..67ce9a74f2 100644
--- a/src/corelib/kernel/qproperty_p.h
+++ b/src/corelib/kernel/qproperty_p.h
@@ -245,13 +245,6 @@ public:
     void clearDependencyObservers() {
         for (size_t i = 0; i < qMin(dependencyObserverCount, inlineDependencyObservers.size()); ++i) {
             QPropertyObserverPointer p{&inlineDependencyObservers[i]};
-            if (p.ptr->next.tag() == QPropertyObserver::ActivelyExecuting) {
-                *(p.ptr->nodeState) = nullptr;
-                p.ptr->nodeState = nullptr;
-
-                // set tag to "safer" value, as we return the same observer pointer from allocateDependencyObserver
-                p.ptr->next.setTag(QPropertyObserver::ObserverNotifiesChangeHandler);
-            }
             p.unlink();
         }
         if (heapObservers)