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| |
| #ifndef QJSENGINE_P_H |
| #define QJSENGINE_P_H |
| |
| // |
| // W A R N I N G |
| // ------------- |
| // |
| // This file is not part of the Qt API. It exists purely as an |
| // implementation detail. This header file may change from version to |
| // version without notice, or even be removed. |
| // |
| // We mean it. |
| // |
| |
| #include <QtCore/private/qobject_p.h> |
| #include <QtCore/qmutex.h> |
| #include "qjsengine.h" |
| #include "private/qtqmlglobal_p.h" |
| #include <private/qqmlmetatype_p.h> |
| |
| QT_BEGIN_NAMESPACE |
| |
| class QQmlPropertyCache; |
| |
| namespace QV4 { |
| struct ExecutionEngine; |
| } |
| |
| class Q_QML_PRIVATE_EXPORT QJSEnginePrivate : public QObjectPrivate |
| { |
| Q_DECLARE_PUBLIC(QJSEngine) |
| |
| public: |
| static QJSEnginePrivate* get(QJSEngine*e) { return e->d_func(); } |
| static const QJSEnginePrivate* get(const QJSEngine*e) { return e->d_func(); } |
| static QJSEnginePrivate* get(QV4::ExecutionEngine *e); |
| |
| QJSEnginePrivate() = default; |
| ~QJSEnginePrivate() override; |
| |
| static void addToDebugServer(QJSEngine *q); |
| static void removeFromDebugServer(QJSEngine *q); |
| |
| // Locker locks the QQmlEnginePrivate data structures for read and write, if necessary. |
| // Currently, locking is only necessary if the threaded loader is running concurrently. If it is |
| // either idle, or is running with the main thread blocked, no locking is necessary. This way |
| // we only pay for locking when we have to. |
| // Consequently, this class should only be used to protect simple accesses or modifications of the |
| // QQmlEnginePrivate structures or operations that can be guaranteed not to start activity |
| // on the loader thread. |
| // The Locker API is identical to QMutexLocker. Locker reuses the QQmlEnginePrivate::mutex |
| // QMutex instance and multiple Lockers are recursive in the same thread. |
| class Locker |
| { |
| public: |
| inline Locker(const QJSEngine *); |
| inline Locker(const QJSEnginePrivate *); |
| inline ~Locker(); |
| |
| inline void unlock(); |
| inline void relock(); |
| |
| private: |
| const QJSEnginePrivate *m_ep; |
| quint32 m_locked:1; |
| }; |
| |
| // Shared by QQmlEngine |
| mutable QRecursiveMutex mutex; |
| |
| QString uiLanguage; |
| |
| // These methods may be called from the QML loader thread |
| inline QQmlPropertyCache *cache(QObject *obj, int minorVersion = -1, bool doRef = false); |
| inline QQmlPropertyCache *cache(const QMetaObject *, int minorVersion = -1, bool doRef = false); |
| }; |
| |
| QJSEnginePrivate::Locker::Locker(const QJSEngine *e) |
| : m_ep(QJSEnginePrivate::get(e)) |
| { |
| relock(); |
| } |
| |
| QJSEnginePrivate::Locker::Locker(const QJSEnginePrivate *e) |
| : m_ep(e), m_locked(false) |
| { |
| relock(); |
| } |
| |
| QJSEnginePrivate::Locker::~Locker() |
| { |
| unlock(); |
| } |
| |
| void QJSEnginePrivate::Locker::unlock() |
| { |
| if (m_locked) { |
| m_ep->mutex.unlock(); |
| m_locked = false; |
| } |
| } |
| |
| void QJSEnginePrivate::Locker::relock() |
| { |
| Q_ASSERT(!m_locked); |
| m_ep->mutex.lock(); |
| m_locked = true; |
| } |
| |
| /*! |
| Returns a QQmlPropertyCache for \a obj if one is available. |
| |
| If \a obj is null, being deleted or contains a dynamic meta object 0 |
| is returned. |
| |
| The returned cache is not referenced, so if it is to be stored, call addref(). |
| |
| XXX thread There is a potential future race condition in this and all the cache() |
| functions. As the QQmlPropertyCache is returned unreferenced, when called |
| from the loader thread, it is possible that the cache will have been dereferenced |
| and deleted before the loader thread has a chance to use or reference it. This |
| can't currently happen as the cache holds a reference to the |
| QQmlPropertyCache until the QQmlEngine is destroyed. |
| */ |
| QQmlPropertyCache *QJSEnginePrivate::cache(QObject *obj, int minorVersion, bool doRef) |
| { |
| if (!obj || QObjectPrivate::get(obj)->metaObject || QObjectPrivate::get(obj)->wasDeleted) |
| return nullptr; |
| |
| Locker locker(this); |
| const QMetaObject *mo = obj->metaObject(); |
| return QQmlMetaType::propertyCache(mo, minorVersion, doRef); |
| } |
| |
| /*! |
| Returns a QQmlPropertyCache for \a metaObject. |
| |
| As the cache is persisted for the life of the engine, \a metaObject must be |
| a static "compile time" meta-object, or a meta-object that is otherwise known to |
| exist for the lifetime of the QQmlEngine. |
| |
| The returned cache is not referenced, so if it is to be stored, call addref(). |
| */ |
| QQmlPropertyCache *QJSEnginePrivate::cache(const QMetaObject *metaObject, int minorVersion, bool doRef) |
| { |
| Q_ASSERT(metaObject); |
| |
| Locker locker(this); |
| return QQmlMetaType::propertyCache(metaObject, minorVersion, doRef); |
| } |
| |
| |
| QT_END_NAMESPACE |
| |
| #endif // QJSENGINE_P_H |