/**************************************************************************** ** ** Copyright (C) 2019 The Qt Company Ltd. ** Copyright (C) 2013 Olivier Goffart ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the QtCore module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 3 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL3 included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 3 requirements ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 2.0 or (at your option) the GNU General ** Public license version 3 or any later version approved by the KDE Free ** Qt Foundation. The licenses are as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 ** included in the packaging of this file. Please review the following ** information to ensure the GNU General Public License requirements will ** be met: https://www.gnu.org/licenses/gpl-2.0.html and ** https://www.gnu.org/licenses/gpl-3.0.html. ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #ifndef QOBJECT_P_H #define QOBJECT_P_H // // W A R N I N G // ------------- // // This file is not part of the Qt API. It exists for the convenience // of qapplication_*.cpp, qwidget*.cpp and qfiledialog.cpp. This header // file may change from version to version without notice, or even be removed. // // We mean it. // #include #include "QtCore/qobject.h" #include "QtCore/qpointer.h" #include "QtCore/qsharedpointer.h" #include "QtCore/qcoreevent.h" #include "QtCore/qlist.h" #include "QtCore/qvector.h" #include "QtCore/qvariant.h" #include "QtCore/qreadwritelock.h" QT_BEGIN_NAMESPACE class QVariant; class QThreadData; class QObjectConnectionListVector; namespace QtSharedPointer { struct ExternalRefCountData; } /* for Qt Test */ struct QSignalSpyCallbackSet { typedef void (*BeginCallback)(QObject *caller, int signal_or_method_index, void **argv); typedef void (*EndCallback)(QObject *caller, int signal_or_method_index); BeginCallback signal_begin_callback, slot_begin_callback; EndCallback signal_end_callback, slot_end_callback; }; void Q_CORE_EXPORT qt_register_signal_spy_callbacks(QSignalSpyCallbackSet *callback_set); extern Q_CORE_EXPORT QBasicAtomicPointer qt_signal_spy_callback_set; enum { QObjectPrivateVersion = QT_VERSION }; class Q_CORE_EXPORT QAbstractDeclarativeData { public: static void (*destroyed)(QAbstractDeclarativeData *, QObject *); static void (*destroyed_qml1)(QAbstractDeclarativeData *, QObject *); static void (*parentChanged)(QAbstractDeclarativeData *, QObject *, QObject *); static void (*signalEmitted)(QAbstractDeclarativeData *, QObject *, int, void **); static int (*receivers)(QAbstractDeclarativeData *, const QObject *, int); static bool (*isSignalConnected)(QAbstractDeclarativeData *, const QObject *, int); static void (*setWidgetParent)(QObject *, QObject *); // Used by the QML engine to specify parents for widgets. Set by QtWidgets. }; // This is an implementation of QAbstractDeclarativeData that is identical with // the implementation in QtDeclarative and QtQml for the first bit struct QAbstractDeclarativeDataImpl : public QAbstractDeclarativeData { quint32 ownedByQml1:1; quint32 unused: 31; }; class Q_CORE_EXPORT QObjectPrivate : public QObjectData { Q_DECLARE_PUBLIC(QObject) public: struct ExtraData { ExtraData() {} #ifndef QT_NO_USERDATA QVector userData; #endif QList propertyNames; QVector propertyValues; QVector runningTimers; QList > eventFilters; QString objectName; }; typedef void (*StaticMetaCallFunction)(QObject *, QMetaObject::Call, int, void **); struct Connection; struct SignalVector; struct ConnectionOrSignalVector { union { // linked list of orphaned connections that need cleaning up ConnectionOrSignalVector *nextInOrphanList; // linked list of connections connected to slots in this object Connection *next; }; static SignalVector *asSignalVector(ConnectionOrSignalVector *c) { if (reinterpret_cast(c) & 1) return reinterpret_cast(reinterpret_cast(c) & ~quintptr(1u)); return nullptr; } static Connection *fromSignalVector(SignalVector *v) { return reinterpret_cast(reinterpret_cast(v) | quintptr(1u)); } }; struct Connection : public ConnectionOrSignalVector { // linked list of connections connected to slots in this object, next is in base class Connection **prev; // linked list of connections connected to signals in this object QAtomicPointer nextConnectionList; Connection *prevConnectionList; QObject *sender; QAtomicPointer receiver; QAtomicPointer receiverThreadData; union { StaticMetaCallFunction callFunction; QtPrivate::QSlotObjectBase *slotObj; }; QAtomicPointer argumentTypes; QAtomicInt ref_; uint id = 0; ushort method_offset; ushort method_relative; signed int signal_index : 27; // In signal range (see QObjectPrivate::signalIndex()) ushort connectionType : 3; // 0 == auto, 1 == direct, 2 == queued, 4 == blocking ushort isSlotObject : 1; ushort ownArgumentTypes : 1; Connection() : ref_(2), ownArgumentTypes(true) { //ref_ is 2 for the use in the internal lists, and for the use in QMetaObject::Connection } ~Connection(); int method() const { Q_ASSERT(!isSlotObject); return method_offset + method_relative; } void ref() { ref_.ref(); } void freeSlotObject() { if (isSlotObject) { slotObj->destroyIfLastRef(); isSlotObject = false; } } void deref() { if (!ref_.deref()) { Q_ASSERT(!receiver.loadRelaxed()); Q_ASSERT(!isSlotObject); delete this; } } }; // ConnectionList is a singly-linked list struct ConnectionList { QAtomicPointer first; QAtomicPointer last; }; struct Sender { Sender(QObject *receiver, QObject *sender, int signal) : receiver(receiver), sender(sender), signal(signal) { if (receiver) { ConnectionData *cd = receiver->d_func()->connections.loadRelaxed(); previous = cd->currentSender; cd->currentSender = this; } } ~Sender() { if (receiver) receiver->d_func()->connections.loadRelaxed()->currentSender = previous; } void receiverDeleted() { Sender *s = this; while (s) { s->receiver = nullptr; s = s->previous; } } Sender *previous = nullptr; QObject *receiver; QObject *sender; int signal; }; struct SignalVector : public ConnectionOrSignalVector { quintptr allocated; // ConnectionList signals[] ConnectionList &at(int i) { return reinterpret_cast(this + 1)[i + 1]; } const ConnectionList &at(int i) const { return reinterpret_cast(this + 1)[i + 1]; } int count() const { return static_cast(allocated); } }; /* This contains the all connections from and to an object. The signalVector contains the lists of connections for a given signal. The index in the vector correspond to the signal index. The signal index is the one returned by QObjectPrivate::signalIndex (not QMetaObject::indexOfSignal). allsignals contains a list of special connections that will get invoked on any signal emission. This is done by connecting to signal index -1. This vector is protected by the object mutex (signalSlotLock()) Each Connection is also part of a 'senders' linked list. This one contains all connections connected to a slot in this object. The mutex of the receiver must be locked when touching the pointers of this linked list. */ struct ConnectionData { // the id below is used to avoid activating new connections. When the object gets // deleted it's set to 0, so that signal emission stops QAtomicInteger currentConnectionId; QAtomicInt ref; QAtomicPointer signalVector; Connection *senders = nullptr; Sender *currentSender = nullptr; // object currently activating the object QAtomicPointer orphaned; ~ConnectionData() { Q_ASSERT(ref.loadRelaxed() == 0); auto *c = orphaned.fetchAndStoreRelaxed(nullptr); if (c) deleteOrphaned(c); SignalVector *v = signalVector.loadRelaxed(); if (v) free(v); } // must be called on the senders connection data // assumes the senders and receivers lock are held void removeConnection(Connection *c); 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, lockPolicy); } void cleanOrphanedConnectionsImpl(QObject *sender, LockPolicy lockPolicy); ConnectionList &connectionsForSignal(int signal) { return signalVector.loadRelaxed()->at(signal); } void resizeSignalVector(uint size) { SignalVector *vector = this->signalVector.loadRelaxed(); if (vector && vector->allocated > size) return; size = (size + 7) & ~7; SignalVector *newVector = reinterpret_cast(malloc(sizeof(SignalVector) + (size + 1) * sizeof(ConnectionList))); int start = -1; if (vector) { memcpy(newVector, vector, sizeof(SignalVector) + (vector->allocated + 1) * sizeof(ConnectionList)); start = vector->count(); } for (int i = start; i < int(size); ++i) newVector->at(i) = ConnectionList(); newVector->next = nullptr; newVector->allocated = size; signalVector.storeRelaxed(newVector); if (vector) { Connection *o = nullptr; /* No ABA issue here: When adding a node, we only care about the list head, it doesn't * matter if the tail changes. */ do { o = orphaned.loadRelaxed(); vector->nextInOrphanList = o; } while (!orphaned.testAndSetRelease(o, ConnectionOrSignalVector::fromSignalVector(vector))); } } int signalVectorCount() const { return signalVector.loadAcquire() ? signalVector.loadRelaxed()->count() : -1; } static void deleteOrphaned(ConnectionOrSignalVector *c); }; QObjectPrivate(int version = QObjectPrivateVersion); virtual ~QObjectPrivate(); void deleteChildren(); inline void checkForIncompatibleLibraryVersion(int version) const; void setParent_helper(QObject *); void moveToThread_helper(); void setThreadData_helper(QThreadData *currentData, QThreadData *targetData); void _q_reregisterTimers(void *pointer); bool isSender(const QObject *receiver, const char *signal) const; QObjectList receiverList(const char *signal) const; QObjectList senderList() const; void addConnection(int signal, Connection *c); static QObjectPrivate *get(QObject *o) { return o->d_func(); } static const QObjectPrivate *get(const QObject *o) { return o->d_func(); } int signalIndex(const char *signalName, const QMetaObject **meta = nullptr) const; bool isSignalConnected(uint signalIdx, bool checkDeclarative = true) const; bool maybeSignalConnected(uint signalIndex) const; inline bool isDeclarativeSignalConnected(uint signalIdx) const; // To allow abitrary objects to call connectNotify()/disconnectNotify() without making // the API public in QObject. This is used by QQmlNotifierEndpoint. inline void connectNotify(const QMetaMethod &signal); inline void disconnectNotify(const QMetaMethod &signal); template static inline QMetaObject::Connection connect(const typename QtPrivate::FunctionPointer::Object *sender, Func1 signal, const typename QtPrivate::FunctionPointer::Object *receiverPrivate, Func2 slot, Qt::ConnectionType type = Qt::AutoConnection); template static inline bool disconnect(const typename QtPrivate::FunctionPointer::Object *sender, Func1 signal, const typename QtPrivate::FunctionPointer::Object *receiverPrivate, Func2 slot); static QMetaObject::Connection connectImpl(const QObject *sender, int signal_index, const QObject *receiver, void **slot, QtPrivate::QSlotObjectBase *slotObj, Qt::ConnectionType type, const int *types, const QMetaObject *senderMetaObject); static QMetaObject::Connection connect(const QObject *sender, int signal_index, QtPrivate::QSlotObjectBase *slotObj, Qt::ConnectionType type); static QMetaObject::Connection connect(const QObject *sender, int signal_index, const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj, Qt::ConnectionType type); static bool disconnect(const QObject *sender, int signal_index, void **slot); static bool disconnect(const QObject *sender, int signal_index, const QObject *receiver, void **slot); void ensureConnectionData() { if (connections.loadRelaxed()) return; ConnectionData *cd = new ConnectionData; cd->ref.ref(); connections.storeRelaxed(cd); } public: ExtraData *extraData; // extra data set by the user // This atomic requires acquire/release semantics in a few places, // e.g. QObject::moveToThread must synchronize with QCoreApplication::postEvent, // because postEvent is thread-safe. // However, most of the code paths involving QObject are only reentrant and // not thread-safe, so synchronization should not be necessary there. QAtomicPointer threadData; // id of the thread that owns the object using ConnectionDataPointer = QExplicitlySharedDataPointer; QAtomicPointer connections; union { QObject *currentChildBeingDeleted; // should only be used when QObjectData::isDeletingChildren is set QAbstractDeclarativeData *declarativeData; //extra data used by the declarative module }; // these objects are all used to indicate that a QObject was deleted // plus QPointer, which keeps a separate list QAtomicPointer sharedRefcount; }; Q_DECLARE_TYPEINFO(QObjectPrivate::ConnectionList, Q_MOVABLE_TYPE); /* Catch mixing of incompatible library versions. Should be called from the constructor of every non-final subclass of QObjectPrivate, to ensure we catch incompatibilities between the intermediate base and subclasses thereof. */ inline void QObjectPrivate::checkForIncompatibleLibraryVersion(int version) const { #if defined(QT_BUILD_INTERNAL) // Don't check the version parameter in internal builds. // This allows incompatible versions to be loaded, possibly for testing. Q_UNUSED(version); #else if (Q_UNLIKELY(version != QObjectPrivateVersion)) { qFatal("Cannot mix incompatible Qt library (%d.%d.%d) with this library (%d.%d.%d)", (version >> 16) & 0xff, (version >> 8) & 0xff, version & 0xff, (QObjectPrivateVersion >> 16) & 0xff, (QObjectPrivateVersion >> 8) & 0xff, QObjectPrivateVersion & 0xff); } #endif } inline bool QObjectPrivate::isDeclarativeSignalConnected(uint signal_index) const { return !isDeletingChildren && declarativeData && QAbstractDeclarativeData::isSignalConnected && QAbstractDeclarativeData::isSignalConnected(declarativeData, q_func(), signal_index); } inline void QObjectPrivate::connectNotify(const QMetaMethod &signal) { q_ptr->connectNotify(signal); } inline void QObjectPrivate::disconnectNotify(const QMetaMethod &signal) { q_ptr->disconnectNotify(signal); } namespace QtPrivate { template class QPrivateSlotObject : public QSlotObjectBase { typedef QtPrivate::FunctionPointer FuncType; Func function; static void impl(int which, QSlotObjectBase *this_, QObject *r, void **a, bool *ret) { switch (which) { case Destroy: delete static_cast(this_); break; case Call: FuncType::template call(static_cast(this_)->function, static_cast(QObjectPrivate::get(r)), a); break; case Compare: *ret = *reinterpret_cast(a) == static_cast(this_)->function; break; case NumOperations: ; } } public: explicit QPrivateSlotObject(Func f) : QSlotObjectBase(&impl), function(f) {} }; } //namespace QtPrivate template inline QMetaObject::Connection QObjectPrivate::connect(const typename QtPrivate::FunctionPointer::Object *sender, Func1 signal, const typename QtPrivate::FunctionPointer::Object *receiverPrivate, Func2 slot, Qt::ConnectionType type) { typedef QtPrivate::FunctionPointer SignalType; typedef QtPrivate::FunctionPointer SlotType; Q_STATIC_ASSERT_X(QtPrivate::HasQ_OBJECT_Macro::Value, "No Q_OBJECT in the class with the signal"); //compilation error if the arguments does not match. Q_STATIC_ASSERT_X(int(SignalType::ArgumentCount) >= int(SlotType::ArgumentCount), "The slot requires more arguments than the signal provides."); Q_STATIC_ASSERT_X((QtPrivate::CheckCompatibleArguments::value), "Signal and slot arguments are not compatible."); Q_STATIC_ASSERT_X((QtPrivate::AreArgumentsCompatible::value), "Return type of the slot is not compatible with the return type of the signal."); const int *types = nullptr; if (type == Qt::QueuedConnection || type == Qt::BlockingQueuedConnection) types = QtPrivate::ConnectionTypes::types(); return QObject::connectImpl(sender, reinterpret_cast(&signal), receiverPrivate->q_ptr, reinterpret_cast(&slot), new QtPrivate::QPrivateSlotObject::Value, typename SignalType::ReturnType>(slot), type, types, &SignalType::Object::staticMetaObject); } template bool QObjectPrivate::disconnect(const typename QtPrivate::FunctionPointer< Func1 >::Object* sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object* receiverPrivate, Func2 slot) { typedef QtPrivate::FunctionPointer SignalType; typedef QtPrivate::FunctionPointer SlotType; Q_STATIC_ASSERT_X(QtPrivate::HasQ_OBJECT_Macro::Value, "No Q_OBJECT in the class with the signal"); //compilation error if the arguments does not match. Q_STATIC_ASSERT_X((QtPrivate::CheckCompatibleArguments::value), "Signal and slot arguments are not compatible."); return QObject::disconnectImpl(sender, reinterpret_cast(&signal), receiverPrivate->q_ptr, reinterpret_cast(&slot), &SignalType::Object::staticMetaObject); } Q_DECLARE_TYPEINFO(QObjectPrivate::Connection, Q_MOVABLE_TYPE); Q_DECLARE_TYPEINFO(QObjectPrivate::Sender, Q_MOVABLE_TYPE); class QSemaphore; class Q_CORE_EXPORT QAbstractMetaCallEvent : public QEvent { public: QAbstractMetaCallEvent(const QObject *sender, int signalId, QSemaphore *semaphore = nullptr) : QEvent(MetaCall), signalId_(signalId), sender_(sender) #if QT_CONFIG(thread) , semaphore_(semaphore) #endif { Q_UNUSED(semaphore); } ~QAbstractMetaCallEvent(); virtual void placeMetaCall(QObject *object) = 0; inline const QObject *sender() const { return sender_; } inline int signalId() const { return signalId_; } private: int signalId_; const QObject *sender_; #if QT_CONFIG(thread) QSemaphore *semaphore_; #endif }; class Q_CORE_EXPORT QMetaCallEvent : public QAbstractMetaCallEvent { public: // blocking queued with semaphore - args always owned by caller QMetaCallEvent(ushort method_offset, ushort method_relative, QObjectPrivate::StaticMetaCallFunction callFunction, const QObject *sender, int signalId, void **args, QSemaphore *semaphore); QMetaCallEvent(QtPrivate::QSlotObjectBase *slotObj, const QObject *sender, int signalId, void **args, QSemaphore *semaphore); // queued - args allocated by event, copied by caller QMetaCallEvent(ushort method_offset, ushort method_relative, QObjectPrivate::StaticMetaCallFunction callFunction, const QObject *sender, int signalId, int nargs); QMetaCallEvent(QtPrivate::QSlotObjectBase *slotObj, const QObject *sender, int signalId, int nargs); ~QMetaCallEvent() override; inline int id() const { return d.method_offset_ + d.method_relative_; } inline const void * const* args() const { return d.args_; } inline void ** args() { return d.args_; } inline const int *types() const { return reinterpret_cast(d.args_ + d.nargs_); } inline int *types() { return reinterpret_cast(d.args_ + d.nargs_); } virtual void placeMetaCall(QObject *object) override; private: inline void allocArgs(); struct Data { QtPrivate::QSlotObjectBase *slotObj_; void **args_; QObjectPrivate::StaticMetaCallFunction callFunction_; int nargs_; ushort method_offset_; ushort method_relative_; } d; // preallocate enough space for three arguments char prealloc_[3*(sizeof(void*) + sizeof(int))]; }; class QBoolBlocker { Q_DISABLE_COPY_MOVE(QBoolBlocker) public: explicit inline QBoolBlocker(bool &b, bool value=true):block(b), reset(b){block = value;} inline ~QBoolBlocker(){block = reset; } private: bool █ bool reset; }; void Q_CORE_EXPORT qDeleteInEventHandler(QObject *o); struct QAbstractDynamicMetaObject; struct Q_CORE_EXPORT QDynamicMetaObjectData { virtual ~QDynamicMetaObjectData(); virtual void objectDestroyed(QObject *) { delete this; } virtual QAbstractDynamicMetaObject *toDynamicMetaObject(QObject *) = 0; virtual int metaCall(QObject *, QMetaObject::Call, int _id, void **) = 0; }; struct Q_CORE_EXPORT QAbstractDynamicMetaObject : public QDynamicMetaObjectData, public QMetaObject { ~QAbstractDynamicMetaObject(); QAbstractDynamicMetaObject *toDynamicMetaObject(QObject *) override { return this; } virtual int createProperty(const char *, const char *) { return -1; } int metaCall(QObject *, QMetaObject::Call c, int _id, void **a) override { return metaCall(c, _id, a); } virtual int metaCall(QMetaObject::Call, int _id, void **) { return _id; } // Compat overload }; QT_END_NAMESPACE #endif // QOBJECT_P_H