From 6778b247a8c20adfb3f4e3094077baae43f3e65c Mon Sep 17 00:00:00 2001
From: Lars Knoll <lars.knoll@qt.io>
Date: Tue, 25 Aug 2020 12:27:09 +0200
Subject: Add a QBindingStorage class

QBindingStorage is a class that can store a set of binding objects
for the properties of a QObject. This will get used to reduce the
memory overhead of the property system when adding bindable properties
to QObject based classes.

The binding storage has a pointer to the TLS entry containing the
currently evaluating binding. Like that we avoid repeated TLS
lookups and reduce the overhead of the property system to one
pointer lookup and one compare for the case that properties
aren't being used.

Each QObject now owns one binding storage object, that can be used to
store binding data for properties that members of the QObject.

Change-Id: I27427c03c2ba281f072e074be96147bdbcaac246
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
---
 src/corelib/kernel/qobject.cpp | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

(limited to 'src/corelib/kernel/qobject.cpp')

diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 4d0523c898..5bb225d396 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -1532,6 +1532,10 @@ void QObject::moveToThread(QThread *targetThread)
         qWarning("QObject::moveToThread: Widgets cannot be moved to a new thread");
         return;
     }
+    if (!d->bindingStorage.isEmpty()) {
+        qWarning("QObject::moveToThread: Can not move objects that contain bindings or are used in bindings to a new thread.");
+        return;
+    }
 
     QThreadData *currentData = QThreadData::current();
     QThreadData *targetData = targetThread ? QThreadData::get2(targetThread) : nullptr;
@@ -4046,6 +4050,24 @@ QList<QByteArray> QObject::dynamicPropertyNames() const
     return QList<QByteArray>();
 }
 
+/*!
+    \internal
+*/
+QBindingStorage *QObject::bindingStorage()
+{
+    Q_D(QObject);
+    return &d->bindingStorage;
+}
+
+/*!
+    \internal
+*/
+const QBindingStorage *QObject::bindingStorage() const
+{
+    Q_D(const QObject);
+    return &d->bindingStorage;
+}
+
 #endif // QT_NO_PROPERTIES
 
 
-- 
cgit v1.2.3