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39
40#ifndef QQMLVME_P_H
41#define QQMLVME_P_H
42
43//
44// W A R N I N G
45// -------------
46//
47// This file is not part of the Qt API. It exists purely as an
48// implementation detail. This header file may change from version to
49// version without notice, or even be removed.
50//
51// We mean it.
52//
53
54#include "qqmlerror.h"
55#include <private/qbitfield_p.h>
56#include <private/qrecursionwatcher_p.h>
57
58#include <QtCore/QStack>
59#include <QtCore/QString>
60#include <QtCore/qelapsedtimer.h>
61#include <QtCore/qcoreapplication.h>
62#include <QtCore/qtypeinfo.h>
63
64#include <private/qqmlengine_p.h>
65#include <private/qfinitestack_p.h>
66
67#include <atomic>
68
69QT_BEGIN_NAMESPACE
70
71class QObject;
72class QJSValue;
73class QQmlScriptData;
74class QQmlContextData;
75
76namespace QQmlVMETypes {
77 struct List
78 {
79 List() : type(0) {}
80 List(int t) : type(t) {}
81
82 int type;
83 QQmlListProperty<void> qListProperty;
84 };
85 struct State {
86 enum Flag { Deferred = 0x00000001 };
87
88 State() : flags(0), context(nullptr), instructionStream(nullptr) {}
89 quint32 flags;
90 QQmlContextData *context;
91 const char *instructionStream;
92 QBitField bindingSkipList;
93 };
94}
95Q_DECLARE_TYPEINFO(QQmlVMETypes::List, Q_PRIMITIVE_TYPE | Q_MOVABLE_TYPE);
96template<>
97class QTypeInfo<QQmlVMETypes::State> : public QTypeInfoMerger<QQmlVMETypes::State, QBitField> {}; //Q_DECLARE_TYPEINFO
98
99class QQmlInstantiationInterrupt {
100public:
101 inline QQmlInstantiationInterrupt();
102 // ### Qt 6: remove
103 inline QQmlInstantiationInterrupt(volatile bool *runWhile, qint64 nsecs=0);
104 inline QQmlInstantiationInterrupt(std::atomic<bool> *runWhile, qint64 nsecs = 0);
105 inline QQmlInstantiationInterrupt(qint64 nsecs);
106
107 inline void reset();
108 inline bool shouldInterrupt() const;
109private:
110 enum Mode { None, Time, LegacyFlag, Flag }; // ### Qt 6: remove LegacyFlag
111 Mode mode;
112 QElapsedTimer timer;
113 qint64 nsecs = 0;
114 volatile bool *runWhileLegacy = nullptr; // ### Qt 6: remove
115 std::atomic<bool> *runWhile = nullptr;
116};
117
118class Q_QML_PRIVATE_EXPORT QQmlVME
119{
120public:
121 static void enableComponentComplete();
122 static void disableComponentComplete();
123 static bool componentCompleteEnabled();
124
125private:
126 static bool s_enableComponentComplete;
127};
128
129// Used to check that a QQmlVME that is interrupted mid-execution
130// is still valid. Checks all the objects and contexts have not been
131// deleted.
132//
133// VME stands for Virtual Machine Execution. QML files used to
134// be compiled to a byte code data structure that a virtual machine executed
135// (for constructing the tree of QObjects and setting properties).
136class QQmlVMEGuard
137{
138public:
139 QQmlVMEGuard();
140 ~QQmlVMEGuard();
141
142 void guard(QQmlObjectCreator *);
143 void clear();
144
145 bool isOK() const;
146
147private:
148 int m_objectCount;
149 QPointer<QObject> *m_objects;
150 int m_contextCount;
151 QQmlGuardedContextData *m_contexts;
152};
153
154QQmlInstantiationInterrupt::QQmlInstantiationInterrupt()
155 : mode(None)
156{
157}
158
159QQmlInstantiationInterrupt::QQmlInstantiationInterrupt(volatile bool *runWhile, qint64 nsecs)
160 : mode(LegacyFlag), nsecs(nsecs), runWhileLegacy(runWhile)
161{
162}
163
164QQmlInstantiationInterrupt::QQmlInstantiationInterrupt(std::atomic<bool> *runWhile, qint64 nsecs)
165 : mode(Flag), nsecs(nsecs), runWhile(runWhile)
166{
167}
168
169QQmlInstantiationInterrupt::QQmlInstantiationInterrupt(qint64 nsecs)
170 : mode(Time), nsecs(nsecs)
171{
172}
173
174void QQmlInstantiationInterrupt::reset()
175{
176 if (mode == Time || nsecs)
177 timer.start();
178}
179
180bool QQmlInstantiationInterrupt::shouldInterrupt() const
181{
182 switch (mode) {
183 case None:
184 return false;
185 case Time:
186 return timer.nsecsElapsed() > nsecs;
187 case LegacyFlag:
188 return !*runWhileLegacy || (nsecs && timer.nsecsElapsed() > nsecs);
189 case Flag:
190 return !runWhile->load(m: std::memory_order_acquire) || (nsecs && timer.nsecsElapsed() > nsecs);
191 }
192 Q_UNREACHABLE();
193 return false;
194}
195
196QT_END_NAMESPACE
197
198#endif // QQMLVME_P_H
199

source code of qtdeclarative/src/qml/qml/qqmlvme_p.h