Make Qt exception safer.

Squashed commit of the branch haralds-haralds-qt-s60-topics/topic/exceptions,
which also contains the full history.

Rev-By: Harald Fernengel
Rev-By: Ralf Engels

1 files changed, 626 insertions, 2 deletions

diff --git a/tests/auto/exceptionsafety/tst_exceptionsafety.cpp b/tests/auto/exceptionsafety/tst_exceptionsafety.cpp
index 9c4f78d..8ed2913 100644
--- a/tests/auto/exceptionsafety/tst_exceptionsafety.cpp
+++ b/tests/auto/exceptionsafety/tst_exceptionsafety.cpp
@@ -52,9 +52,16 @@ class tst_ExceptionSafety: public QObject
     Q_OBJECT
 private slots:
     void exceptionInSlot();
+    void exceptionVector();
+    void exceptionHash();
+    void exceptionMap();
+    void exceptionList();
+    void exceptionLinkedList();
+    void exceptionEventLoop();
+    void exceptionSignalSlot();
 };
 
-class Emitter: public QObject
+class Emitter : public QObject
 {
     Q_OBJECT
 public:
@@ -63,13 +70,111 @@ signals:
     void testSignal();
 };
 
-class ExceptionThrower: public QObject
+class ExceptionThrower : public QObject
 {
     Q_OBJECT
 public slots:
     void thrower() { throw 5; }
 };
 
+class Receiver : public QObject
+{
+    Q_OBJECT
+public:
+    Receiver()
+        : received(0) {}
+    int received;
+
+public slots:
+    void receiver() { ++received; }
+};
+
+enum ThrowType { ThrowNot = 0, ThrowAtCreate = 1, ThrowAtCopy = 2, ThrowLater = 3, ThrowAtComparison = 4 };
+
+ThrowType throwType = ThrowNot; // global flag to indicate when an exception should be throw. Will be reset when the exception has been generated.
+
+int objCounter = 0;
+
+/*! Class that does not throw any exceptions. Used as baseclass for all the other ones.
+ */
+template <int T>
+class FlexibleThrower
+{
+    public:
+        FlexibleThrower() : _value(-1) {
+            if( throwType == ThrowAtCreate ) {
+                throwType = ThrowNot;
+                throw ThrowAtCreate;
+            }
+            objCounter++;
+        }
+
+        FlexibleThrower( short value ) : _value(value) {
+            if( throwType == ThrowAtCreate ) {
+                throwType = ThrowNot;
+                throw ThrowAtCreate;
+            }
+            objCounter++;
+        }
+
+        FlexibleThrower(FlexibleThrower const& other ) {
+            // qDebug("cc");
+
+            if( throwType == ThrowAtCopy ) {
+                throwType = ThrowNot;
+                throw ThrowAtCopy;
+
+            } else if( throwType == ThrowLater ) {
+                throwType = ThrowAtCopy;
+            }
+
+            objCounter++;
+            _value = other.value();
+        }
+
+        ~FlexibleThrower() { objCounter--; }
+
+        bool operator==(const FlexibleThrower<T> &t) const
+        {
+            // qDebug("vv == %d %d", value(), t.value());
+            if( throwType == ThrowAtComparison ) {
+                throwType = ThrowNot;
+                throw ThrowAtComparison;
+            }
+            return value()==t.value();
+        }
+
+        bool operator<(const FlexibleThrower<T> &t) const
+        {
+            // qDebug("vv < %d %d", value(), t.value());
+            if( throwType == ThrowAtComparison ) {
+                throwType = ThrowNot;
+                throw ThrowAtComparison;
+            }
+            return value()<t.value();
+        }
+
+        int value() const
+        { return (int)_value; }
+
+        short _value;
+        char dummy[T];
+};
+
+uint qHash(const FlexibleThrower<2>& t)
+{
+    // qDebug("ha");
+    if( throwType == ThrowAtComparison ) {
+        throwType = ThrowNot;
+        throw ThrowAtComparison;
+    }
+    return (uint)t.value();
+}
+
+typedef FlexibleThrower<2> FlexibleThrowerSmall;
+typedef QMap<FlexibleThrowerSmall,FlexibleThrowerSmall> MyMap;
+typedef QHash<FlexibleThrowerSmall,FlexibleThrowerSmall> MyHash;
+
 // connect a signal to a slot that throws an exception
 // run this through valgrind to make sure it doesn't corrupt
 void tst_ExceptionSafety::exceptionInSlot()
@@ -86,6 +191,525 @@ void tst_ExceptionSafety::exceptionInSlot()
     }
 }
 
+void tst_ExceptionSafety::exceptionList() {
+
+    {
+        QList<FlexibleThrowerSmall> list;
+        QList<FlexibleThrowerSmall> list2;
+        QList<FlexibleThrowerSmall> list3;
+
+        for( int i = 0; i<10; i++ )
+            list.append( FlexibleThrowerSmall(i) );
+
+        try {
+            throwType = ThrowAtCopy;
+            list.append( FlexibleThrowerSmall(10));
+        } catch (...) {
+        }
+        QCOMPARE( list.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            list.prepend( FlexibleThrowerSmall(10));
+        } catch (...) {
+        }
+        QCOMPARE( list.at(0).value(), 0 );
+        QCOMPARE( list.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            list.insert( 8, FlexibleThrowerSmall(10));
+        } catch (...) {
+        }
+        QCOMPARE( list.at(7).value(), 7 );
+        QCOMPARE( list.at(8).value(), 8 );
+        QCOMPARE( list.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            FlexibleThrowerSmall t = list.takeAt( 6 );
+        } catch (...) {
+        }
+        QCOMPARE( list.at(6).value(), 6 );
+        QCOMPARE( list.at(7).value(), 7 );
+        QCOMPARE( list.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            list3 = list;
+        } catch (...) {
+        }
+        QCOMPARE( list.at(0).value(), 0 );
+        QCOMPARE( list.at(7).value(), 7 );
+        QCOMPARE( list.size(), 10 );
+        QCOMPARE( list3.at(0).value(), 0 );
+        QCOMPARE( list3.at(7).value(), 7 );
+        QCOMPARE( list3.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            list3.append( FlexibleThrowerSmall(11) );
+        } catch (...) {
+        }
+        QCOMPARE( list.at(0).value(), 0 );
+        QCOMPARE( list.at(7).value(), 7 );
+        QCOMPARE( list.size(), 10 );
+        QCOMPARE( list3.at(0).value(), 0 );
+        QCOMPARE( list3.at(7).value(), 7 );
+        QCOMPARE( list3.size(), 10 );
+
+        try {
+            list2.clear();
+            list2.append( FlexibleThrowerSmall(11));
+            throwType = ThrowAtCopy;
+            list3 = list+list2;
+        } catch (...) {
+        }
+        QCOMPARE( list.at(0).value(), 0 );
+        QCOMPARE( list.at(7).value(), 7 );
+        QCOMPARE( list.size(), 10 );
+
+        // check that copy on write works atomar
+        list2.clear();
+        list2.append( FlexibleThrowerSmall(11));
+        list3 = list+list2;
+        try {
+            throwType = ThrowAtCreate;
+            list3[7]=FlexibleThrowerSmall(12);
+        } catch (...) {
+        }
+        QCOMPARE( list.at(7).value(), 7 );
+        QCOMPARE( list.size(), 10 );
+        QCOMPARE( list3.at(7).value(), 7 );
+        QCOMPARE( list3.size(), 11 );
+
+    }
+    QCOMPARE(objCounter, 0 ); // check that every object has been freed
+}
+
+void tst_ExceptionSafety::exceptionLinkedList() {
+
+    {
+        QLinkedList<FlexibleThrowerSmall> list;
+        QLinkedList<FlexibleThrowerSmall> list2;
+        QLinkedList<FlexibleThrowerSmall> list3;
+
+        for( int i = 0; i<10; i++ )
+            list.append( FlexibleThrowerSmall(i) );
+
+        try {
+            throwType = ThrowAtCopy;
+            list.append( FlexibleThrowerSmall(10));
+        } catch (...) {
+        }
+        QCOMPARE( list.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            list.prepend( FlexibleThrowerSmall(10));
+        } catch (...) {
+        }
+        QCOMPARE( list.first().value(), 0 );
+        QCOMPARE( list.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            list3 = list;
+            list3.append( FlexibleThrowerSmall(11) );
+        } catch (...) {
+        }
+        QCOMPARE( list.first().value(), 0 );
+        QCOMPARE( list.size(), 10 );
+        QCOMPARE( list3.size(), 10 );
+    }
+    QCOMPARE(objCounter, 0 ); // check that every object has been freed
+}
+
+void tst_ExceptionSafety::exceptionVector() {
+
+    {
+        QVector<FlexibleThrowerSmall> vector;
+        QVector<FlexibleThrowerSmall> vector2;
+        QVector<FlexibleThrowerSmall> vector3;
+
+        for (int i = 0; i<10; i++)
+            vector.append( FlexibleThrowerSmall(i) );
+
+        try {
+            throwType = ThrowAtCopy;
+            vector.append( FlexibleThrowerSmall(10));
+        } catch (...) {
+        }
+        QCOMPARE( vector.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            vector.prepend( FlexibleThrowerSmall(10));
+        } catch (...) {
+        }
+        QCOMPARE( vector.at(0).value(), 0 );
+        QCOMPARE( vector.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            vector.insert( 8, FlexibleThrowerSmall(10));
+        } catch (...) {
+        }
+        QCOMPARE( vector.at(7).value(), 7 );
+        QCOMPARE( vector.at(8).value(), 8 );
+        QCOMPARE( vector.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            vector3 = vector;
+        } catch (...) {
+        }
+        QCOMPARE( vector.at(0).value(), 0 );
+        QCOMPARE( vector.at(7).value(), 7 );
+        QCOMPARE( vector.size(), 10 );
+        QCOMPARE( vector3.at(0).value(), 0 );
+        QCOMPARE( vector3.at(7).value(), 7 );
+        QCOMPARE( vector3.size(), 10 );
+
+        try {
+            throwType = ThrowAtCopy;
+            vector3.append( FlexibleThrowerSmall(11) );
+        } catch (...) {
+        }
+        QCOMPARE( vector.at(0).value(), 0 );
+        QCOMPARE( vector.at(7).value(), 7 );
+        QCOMPARE( vector.size(), 10 );
+        QCOMPARE( vector3.at(0).value(), 0 );
+        QCOMPARE( vector3.at(7).value(), 7 );
+
+        try {
+            vector2.clear();
+            vector2.append( FlexibleThrowerSmall(11));
+            throwType = ThrowAtCopy;
+            vector3 = vector+vector2;
+        } catch (...) {
+        }
+        QCOMPARE( vector.at(0).value(), 0 );
+        QCOMPARE( vector.at(7).value(), 7 );
+        QCOMPARE( vector.size(), 10 );
+
+        // check that copy on write works atomar
+        vector2.clear();
+        vector2.append( FlexibleThrowerSmall(11));
+        vector3 = vector+vector2;
+        try {
+            throwType = ThrowAtCreate;
+            vector3[7]=FlexibleThrowerSmall(12);
+        } catch (...) {
+        }
+        QCOMPARE( vector.at(7).value(), 7 );
+        QCOMPARE( vector.size(), 10 );
+        QCOMPARE( vector3.at(7).value(), 7 );
+        QCOMPARE( vector3.size(), 11 );
+
+        try {
+            throwType = ThrowAtCreate;
+            vector.resize(15);
+        } catch (...) {
+        }
+        QCOMPARE( vector.at(7).value(), 7 );
+        QCOMPARE( vector.size(), 10 );
+
+        try {
+            throwType = ThrowAtCreate;
+            vector.resize(15);
+        } catch (...) {
+        }
+        QCOMPARE( vector.at(7).value(), 7 );
+        QCOMPARE( vector.size(), 10 );
+
+        try {
+            throwType = ThrowLater;
+            vector.fill(FlexibleThrowerSmall(1), 15);
+        } catch (...) {
+        }
+        QCOMPARE( vector.at(0).value(), 0 );
+        QCOMPARE( vector.size(), 10 );
+
+
+    }
+    QCOMPARE(objCounter, 0 ); // check that every object has been freed
+}
+
+
+void tst_ExceptionSafety::exceptionMap() {
+
+    {
+        MyMap map;
+        MyMap map2;
+        MyMap map3;
+
+        throwType = ThrowNot;
+        for (int i = 0; i<10; i++)
+            map[ FlexibleThrowerSmall(i) ] = FlexibleThrowerSmall(i);
+
+        return; // further test are deactivated until Map is fixed.
+
+        for( int i = ThrowAtCopy; i<=ThrowAtComparison; i++ ) {
+            try {
+                throwType = (ThrowType)i;
+                map[ FlexibleThrowerSmall(10) ] = FlexibleThrowerSmall(10);
+            } catch(...) {
+            }
+            QCOMPARE( map.size(), 10 );
+            QCOMPARE( map[ FlexibleThrowerSmall(1) ], FlexibleThrowerSmall(1) );
+        }
+
+        map2 = map;
+        try {
+            throwType = ThrowLater;
+            map2[ FlexibleThrowerSmall(10) ] = FlexibleThrowerSmall(10);
+        } catch(...) {
+        }
+        /* qDebug("%d %d", map.size(), map2.size() );
+        for( int i=0; i<map.size(); i++ )
+            qDebug( "Value at %d: %d",i, map.value(FlexibleThrowerSmall(i), FlexibleThrowerSmall()).value() );
+        QCOMPARE( map.value(FlexibleThrowerSmall(1), FlexibleThrowerSmall()), FlexibleThrowerSmall(1) );
+        qDebug( "Value at %d: %d",1, map[FlexibleThrowerSmall(1)].value() );
+        qDebug("%d %d", map.size(), map2.size() );
+        */
+        QCOMPARE( map[ FlexibleThrowerSmall(1) ], FlexibleThrowerSmall(1) );
+        QCOMPARE( map.size(), 10 );
+        QCOMPARE( map2[ FlexibleThrowerSmall(1) ], FlexibleThrowerSmall(1) );
+        QCOMPARE( map2.size(), 10 );
+
+    }
+    QCOMPARE(objCounter, 0 ); // check that every object has been freed
+}
+
+void tst_ExceptionSafety::exceptionHash() {
+
+    {
+        MyHash hash;
+        MyHash hash2;
+        MyHash hash3;
+
+        for( int i = 0; i<10; i++ )
+            hash[ FlexibleThrowerSmall(i) ] = FlexibleThrowerSmall(i);
+
+        for( int i = ThrowAtCopy; i<=ThrowAtComparison; i++ ) {
+            try {
+                throwType = (ThrowType)i;
+                hash[ FlexibleThrowerSmall(10) ] = FlexibleThrowerSmall(10);
+            } catch(...) {
+            }
+            QCOMPARE( hash.size(), 10 );
+        }
+
+        hash2 = hash;
+        try {
+            throwType = ThrowLater;
+            hash2[ FlexibleThrowerSmall(10) ] = FlexibleThrowerSmall(10);
+        } catch(...) {
+        }
+        QCOMPARE( hash[ FlexibleThrowerSmall(1) ], FlexibleThrowerSmall(1) );
+        QCOMPARE( hash.size(), 10 );
+        QCOMPARE( hash2[ FlexibleThrowerSmall(1) ], FlexibleThrowerSmall(1) );
+        QCOMPARE( hash2.size(), 10 );
+
+        hash2.clear();
+        try {
+            throwType = ThrowLater;
+            hash2.reserve(30);
+        } catch(...) {
+        }
+        QCOMPARE( hash2.size(), 0 );
+
+        /*
+           try {
+           throwType = ThrowAtCopy;
+           hash.prepend( FlexibleThrowerSmall(10));
+           } catch (...) {
+           }
+           QCOMPARE( hash.at(0).value(), 0 );
+           QCOMPARE( hash.size(), 10 );
+
+           try {
+           throwType = ThrowAtCopy;
+           hash.insert( 8, FlexibleThrowerSmall(10));
+           } catch (...) {
+           }
+           QCOMPARE( hash.at(7).value(), 7 );
+           QCOMPARE( hash.at(8).value(), 8 );
+           QCOMPARE( hash.size(), 10 );
+
+           qDebug("val");
+           try {
+           throwType = ThrowAtCopy;
+           hash3 = hash;
+           } catch (...) {
+           }
+           QCOMPARE( hash.at(0).value(), 0 );
+           QCOMPARE( hash.at(7).value(), 7 );
+           QCOMPARE( hash.size(), 10 );
+           QCOMPARE( hash3.at(0).value(), 0 );
+           QCOMPARE( hash3.at(7).value(), 7 );
+           QCOMPARE( hash3.size(), 10 );
+
+           try {
+           throwType = ThrowAtCopy;
+           hash3.append( FlexibleThrowerSmall(11) );
+           } catch (...) {
+           }
+           QCOMPARE( hash.at(0).value(), 0 );
+           QCOMPARE( hash.at(7).value(), 7 );
+           QCOMPARE( hash.size(), 10 );
+           QCOMPARE( hash3.at(0).value(), 0 );
+           QCOMPARE( hash3.at(7).value(), 7 );
+           QCOMPARE( hash3.at(11).value(), 11 );
+
+           try {
+           hash2.clear();
+           hash2.append( FlexibleThrowerSmall(11));
+           throwType = ThrowAtCopy;
+           hash3 = hash+hash2;
+           } catch (...) {
+           }
+           QCOMPARE( hash.at(0).value(), 0 );
+           QCOMPARE( hash.at(7).value(), 7 );
+           QCOMPARE( hash.size(), 10 );
+
+        // check that copy on write works atomar
+        hash2.clear();
+        hash2.append( FlexibleThrowerSmall(11));
+        hash3 = hash+hash2;
+        try {
+        throwType = ThrowAtCopy;
+        hash3[7]=FlexibleThrowerSmall(12);
+        } catch (...) {
+        }
+        QCOMPARE( hash.at(7).value(), 7 );
+        QCOMPARE( hash.size(), 10 );
+        QCOMPARE( hash3.at(7).value(), 7 );
+        QCOMPARE( hash3.size(), 11 );
+        */
+
+
+    }
+    QCOMPARE(objCounter, 0 ); // check that every object has been freed
+}
+
+enum
+{
+    ThrowEventId = QEvent::User + 42,
+    NoThrowEventId = QEvent::User + 43
+};
+
+class ThrowEvent : public QEvent
+{
+public:
+    ThrowEvent()
+        : QEvent(static_cast<QEvent::Type>(ThrowEventId))
+    {
+    }
+};
+
+class NoThrowEvent : public QEvent
+{
+public:
+    NoThrowEvent()
+        : QEvent(static_cast<QEvent::Type>(NoThrowEventId))
+    {}
+};
+
+class TestObject : public QObject
+{
+public:
+    TestObject()
+        : throwEventCount(0), noThrowEventCount(0) {}
+
+    int throwEventCount;
+    int noThrowEventCount;
+
+protected:
+    bool event(QEvent *event)
+    {
+        if (int(event->type()) == ThrowEventId) {
+            throw ++throwEventCount;
+        } else if (int(event->type()) == NoThrowEventId) {
+            ++noThrowEventCount;
+        }
+        return QObject::event(event);
+    }
+};
+
+void tst_ExceptionSafety::exceptionEventLoop()
+{
+    // send an event that throws
+    TestObject obj;
+    ThrowEvent throwEvent;
+    try {
+        qApp->sendEvent(&obj, &throwEvent);
+    } catch (int code) {
+        QCOMPARE(code, 1);
+    }
+    QCOMPARE(obj.throwEventCount, 1);
+
+    // post an event that throws
+    qApp->postEvent(&obj, new ThrowEvent);
+
+    try {
+        qApp->processEvents();
+    } catch (int code) {
+        QCOMPARE(code, 2);
+    }
+    QCOMPARE(obj.throwEventCount, 2);
+
+    // post a normal event, then a throwing event, then a normal event
+    // run this in valgrind to ensure that it doesn't leak.
+
+    qApp->postEvent(&obj, new NoThrowEvent);
+    qApp->postEvent(&obj, new ThrowEvent);
+    qApp->postEvent(&obj, new NoThrowEvent);
+
+    try {
+        qApp->processEvents();
+    } catch (int code) {
+        QCOMPARE(code, 3);
+    }
+    // here, we should have received on non-throwing event and one throwing one
+    QCOMPARE(obj.throwEventCount, 3);
+    QCOMPARE(obj.noThrowEventCount, 1);
+
+    // spin the event loop again
+    qApp->processEvents();
+
+    // now, we should have received the second non-throwing event
+    QCOMPARE(obj.noThrowEventCount, 2);
+}
+
+void tst_ExceptionSafety::exceptionSignalSlot()
+{
+    Emitter e;
+    ExceptionThrower thrower;
+    Receiver r1;
+    Receiver r2;
+
+    // connect a signal to a normal object, a thrower and a normal object again
+    connect(&e, SIGNAL(testSignal()), &r1, SLOT(receiver()));
+    connect(&e, SIGNAL(testSignal()), &thrower, SLOT(thrower()));
+    connect(&e, SIGNAL(testSignal()), &r2, SLOT(receiver()));
+
+    int code = 0;
+    try {
+        e.emitTestSignal();
+    } catch (int c) {
+        code = c;
+    }
+
+    // 5 is the magic number that's thrown by thrower
+    QCOMPARE(code, 5);
+
+    // assumption: slots are called in the connection order
+    QCOMPARE(r1.received, 1);
+    QCOMPARE(r2.received, 0);
+}
+
 QTEST_MAIN(tst_ExceptionSafety)
 #include "tst_exceptionsafety.moc"
 #endif // QT_NO_EXCEPTIONS