Move rarely used QObjectPrivate data to extraData

Move runningTimers, eventFilters and objectName data members to
ExtraData.  Saves 12 bytes per QObject for 95% of use cases
(QObjectPrivate goes from 76B -> 64B).

Change-Id: I5648c89f65a7be3ea51bd703ee8a9dcff6222c3c
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

src/corelib/kernel/qcoreapplication.cpp

@@ -789,10 +789,10 @@ bool QCoreApplication::notify(QObject *receiver, QEvent *event)
 
 bool QCoreApplicationPrivate::sendThroughApplicationEventFilters(QObject *receiver, QEvent *event)
 {
-    if (receiver->d_func()->threadData == this->threadData) {
+    if (receiver->d_func()->threadData == this->threadData && extraData) {
         // application event filters are only called for objects in the GUI thread
-        for (int i = 0; i < eventFilters.size(); ++i) {
-            register QObject *obj = eventFilters.at(i);
+        for (int i = 0; i < extraData->eventFilters.size(); ++i) {
+            register QObject *obj = extraData->eventFilters.at(i);
             if (!obj)
                 continue;
             if (obj->d_func()->threadData != threadData) {
@@ -809,9 +809,9 @@ bool QCoreApplicationPrivate::sendThroughApplicationEventFilters(QObject *receiv
 bool QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject *receiver, QEvent *event)
 {
     Q_Q(QCoreApplication);
-    if (receiver != q) {
-        for (int i = 0; i < receiver->d_func()->eventFilters.size(); ++i) {
-            register QObject *obj = receiver->d_func()->eventFilters.at(i);
+    if (receiver != q && receiver->d_func()->extraData) {
+        for (int i = 0; i < receiver->d_func()->extraData->eventFilters.size(); ++i) {
+            register QObject *obj = receiver->d_func()->extraData->eventFilters.at(i);
             if (!obj)
                 continue;
             if (obj->d_func()->threadData != receiver->d_func()->threadData) {

src/corelib/kernel/qobject.cpp

@@ -70,16 +70,6 @@
 
 QT_BEGIN_NAMESPACE
 
-struct QObjectPrivate::ExtraData
-{
-    ExtraData() {}
-#ifndef QT_NO_USERDATA
-    QVector<QObjectUserData *> userData;
-#endif
-    QList<QByteArray> propertyNames;
-    QList<QVariant> propertyValues;
-};
-
 static int DIRECT_CONNECTION_ONLY = 0;
 
 static int *queuedConnectionTypes(const QList<QByteArray> &typeNames)
@@ -217,14 +207,14 @@ QObjectPrivate::QObjectPrivate(int version)
 
 QObjectPrivate::~QObjectPrivate()
 {
-    if (!runningTimers.isEmpty()) {
+    if (extraData && !extraData->runningTimers.isEmpty()) {
         // unregister pending timers
         if (threadData->eventDispatcher)
             threadData->eventDispatcher->unregisterTimers(q_ptr);
 
         // release the timer ids back to the pool
-        for (int i = 0; i < runningTimers.size(); ++i)
-            QAbstractEventDispatcherPrivate::releaseTimerId(runningTimers.at(i));
+        for (int i = 0; i < extraData->runningTimers.size(); ++i)
+            QAbstractEventDispatcherPrivate::releaseTimerId(extraData->runningTimers.at(i));
     }
 
     if (postedEvents)
@@ -237,8 +227,8 @@ QObjectPrivate::~QObjectPrivate()
 #ifndef QT_NO_USERDATA
     if (extraData)
         qDeleteAll(extraData->userData);
-    delete extraData;
 #endif
+    delete extraData;
 }
 
 /*!\internal
@@ -983,7 +973,7 @@ QObjectPrivate::Connection::~Connection()
 QString QObject::objectName() const
 {
     Q_D(const QObject);
-    return d->objectName;
+    return d->extraData ? d->extraData->objectName : QString();
 }
 
 /*
@@ -992,9 +982,12 @@ QString QObject::objectName() const
 void QObject::setObjectName(const QString &name)
 {
     Q_D(QObject);
-    if (d->objectName != name) {
-        d->objectName = name;
-        emit objectNameChanged(d->objectName);
+    if (!d->extraData)
+        d->extraData = new QObjectPrivate::ExtraData;
+
+    if (d->extraData->objectName != name) {
+        d->extraData->objectName = name;
+        emit objectNameChanged(d->extraData->objectName);
     }
 }
 
@@ -1425,7 +1418,9 @@ int QObject::startTimer(int interval, Qt::TimerType timerType)
         return 0;
     }
     int timerId = d->threadData->eventDispatcher->registerTimer(interval, timerType, this);
-    d->runningTimers.append(timerId);
+    if (!d->extraData)
+        d->extraData = new QObjectPrivate::ExtraData;
+    d->extraData->runningTimers.append(timerId);
     return timerId;
 }
 
@@ -1442,7 +1437,7 @@ void QObject::killTimer(int id)
 {
     Q_D(QObject);
     if (id) {
-        int at = d->runningTimers.indexOf(id);
+        int at = d->extraData ? d->extraData->runningTimers.indexOf(id) : -1;
         if (at == -1) {
             // timer isn't owned by this object
             qWarning("QObject::killTimer(): Error: timer id %d is not valid for object %p (%s), timer has not been killed",
@@ -1455,7 +1450,7 @@ void QObject::killTimer(int id)
         if (d->threadData->eventDispatcher)
             d->threadData->eventDispatcher->unregisterTimer(id);
 
-        d->runningTimers.remove(at);
+        d->extraData->runningTimers.remove(at);
         QAbstractEventDispatcherPrivate::releaseTimerId(id);
     }
 }
@@ -1844,10 +1839,13 @@ void QObject::installEventFilter(QObject *obj)
         return;
     }
 
+    if (!d->extraData)
+        d->extraData = new QObjectPrivate::ExtraData;
+
     // clean up unused items in the list
-    d->eventFilters.removeAll((QObject*)0);
-    d->eventFilters.removeAll(obj);
-    d->eventFilters.prepend(obj);
+    d->extraData->eventFilters.removeAll((QObject*)0);
+    d->extraData->eventFilters.removeAll(obj);
+    d->extraData->eventFilters.prepend(obj);
 }
 
 /*!
@@ -1866,9 +1864,11 @@ void QObject::installEventFilter(QObject *obj)
 void QObject::removeEventFilter(QObject *obj)
 {
     Q_D(QObject);
-    for (int i = 0; i < d->eventFilters.count(); ++i) {
-        if (d->eventFilters.at(i) == obj)
-            d->eventFilters[i] = 0;
+    if (d->extraData) {
+        for (int i = 0; i < d->extraData->eventFilters.count(); ++i) {
+            if (d->extraData->eventFilters.at(i) == obj)
+                d->extraData->eventFilters[i] = 0;
+        }
     }
 }
 

src/corelib/kernel/qobject_p.h

@@ -59,6 +59,7 @@
 #include "QtCore/qcoreevent.h"
 #include "QtCore/qlist.h"
 #include "QtCore/qvector.h"
+#include "QtCore/qvariant.h"
 #include "QtCore/qreadwritelock.h"
 
 QT_BEGIN_NAMESPACE
@@ -97,8 +98,19 @@ class Q_CORE_EXPORT QObjectPrivate : public QObjectData
 {
     Q_DECLARE_PUBLIC(QObject)
 
-    struct ExtraData;
 public:
+    struct ExtraData
+    {
+        ExtraData() {}
+    #ifndef QT_NO_USERDATA
+        QVector<QObjectUserData *> userData;
+    #endif
+        QList<QByteArray> propertyNames;
+        QList<QVariant> propertyValues;
+        QVector<int> runningTimers;
+        QList<QPointer<QObject> > eventFilters;
+        QString objectName;
+    };
 
     typedef void (*StaticMetaCallFunction)(QObject *, QMetaObject::Call, int, void **);
     struct Connection
@@ -179,7 +191,6 @@ public:
     inline bool isSignalConnected(uint signalIdx) const;
 
 public:
-    QString objectName;
     ExtraData *extraData;    // extra data set by the user
     QThreadData *threadData; // id of the thread that owns the object
 
@@ -189,8 +200,6 @@ public:
     Sender *currentSender;   // object currently activating the object
     mutable quint32 connectedSignals[2];
 
-    QVector<int> runningTimers;
-    QList<QPointer<QObject> > eventFilters;
     union {
         QObject *currentChildBeingDeleted;
         QAbstractDeclarativeData *declarativeData; //extra data used by the declarative module

src/corelib/statemachine/qstatemachine.cpp

@@ -1599,7 +1599,7 @@ void QStateMachinePrivate::registerEventTransition(QEventTransition *transition)
     if (!object)
         return;
     QObjectPrivate *od = QObjectPrivate::get(object);
-    if (!od->eventFilters.contains(q))
+    if (!od->extraData || !od->extraData->eventFilters.contains(q))
         object->installEventFilter(q);
     ++qobjectEvents[object][transition->eventType()];
     QEventTransitionPrivate::get(transition)->registered = true;

src/widgets/kernel/qapplication.cpp

@@ -3164,8 +3164,8 @@ bool QApplication::notify(QObject *receiver, QEvent *e)
                 if (!w->hasMouseTracking()
                     && mouse->type() == QEvent::MouseMove && mouse->buttons() == 0) {
                     // but still send them through all application event filters (normally done by notify_helper)
-                    for (int i = 0; i < d->eventFilters.size(); ++i) {
-                        register QObject *obj = d->eventFilters.at(i);
+                    for (int i = 0; d->extraData && i < d->extraData->eventFilters.size(); ++i) {
+                        register QObject *obj = d->extraData->eventFilters.at(i);
                         if (!obj)
                             continue;
                         if (obj->d_func()->threadData != w->d_func()->threadData) {