cleanOrphanedConnectionsImpl: Allow to skip locking

This function is/will be used in a few places where we already have a
lock. Temporarily unlocking and relocking invites all kinds of troubles.
By adding a flag we can instead tell the function that we already hold
the lock.

Change-Id: Ibca089de61133661d5cd75290f2a55c22c5d013c
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
(cherry picked from commit 556fc646cfac4dca43a34f5c4a4f7e6e3ef9104d)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 10 insertions, 3 deletions

diff --git a/src/corelib/kernel/qobject_p.h b/src/corelib/kernel/qobject_p.h
index 4483e2b6ce..8dd29e05ce 100644
--- a/src/corelib/kernel/qobject_p.h
+++ b/src/corelib/kernel/qobject_p.h
@@ -266,12 +266,19 @@ public:
         // must be called on the senders connection data
         // assumes the senders and receivers lock are held
         void removeConnection(Connection *c);
-        void cleanOrphanedConnections(QObject *sender)
+        enum LockPolicy {
+            NeedToLock,
+            // Beware that we need to temporarily release the lock
+            // and thus calling code must carefully consider whether
+            // invariants still hold.
+            AlreadyLockedAndTemporarilyReleasingLock
+        };
+        void cleanOrphanedConnections(QObject *sender, LockPolicy lockPolicy = NeedToLock)
         {
             if (orphaned.loadRelaxed() && ref.loadAcquire() == 1)
-                cleanOrphanedConnectionsImpl(sender);
+                cleanOrphanedConnectionsImpl(sender, lockPolicy);
         }
-        void cleanOrphanedConnectionsImpl(QObject *sender);
+        void cleanOrphanedConnectionsImpl(QObject *sender, LockPolicy lockPolicy);
 
         ConnectionList &connectionsForSignal(int signal)
         {