From 17bea1689abc695d88f13cd15f73b0a59fcffdff Mon Sep 17 00:00:00 2001 From: Orgad Shaneh Date: Sun, 4 Nov 2012 21:21:31 +0200 Subject: QtConcurrent: Fix for leak in QFuture MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To avoid leaking when converting a QFuture to a QFuture we need to have a separate ref. counter for QFuture. When the last QFuture goes out of scope, we need to clean out the result data. backported from qt/qtbase commit 731ba8ed08f80644b403556638c7f6229e678ebe Original commit by Christian Strømme Task-number: QTBUG-27224 Change-Id: I0c6b525cf241b5c559a1bab4e0066cd4de556ea8 Reviewed-by: Christian Stromme --- src/corelib/concurrent/qfutureinterface.cpp | 10 +++++ src/corelib/concurrent/qfutureinterface.h | 15 ++++++-- src/corelib/concurrent/qfutureinterface_p.h | 26 ++++++++++++- tests/auto/qfuture/tst_qfuture.cpp | 30 +++++++++++---- tests/auto/qtconcurrentmap/tst_qtconcurrentmap.cpp | 43 ++++++++++++++++++++++ 5 files changed, 111 insertions(+), 13 deletions(-) diff --git a/src/corelib/concurrent/qfutureinterface.cpp b/src/corelib/concurrent/qfutureinterface.cpp index 9668e5d..6853a1a 100644 --- a/src/corelib/concurrent/qfutureinterface.cpp +++ b/src/corelib/concurrent/qfutureinterface.cpp @@ -419,6 +419,16 @@ bool QFutureInterfaceBase::referenceCountIsOne() const return d->refCount == 1; } +bool QFutureInterfaceBase::refT() const +{ + return d->refCount.refT(); +} + +bool QFutureInterfaceBase::derefT() const +{ + return d->refCount.derefT(); +} + QFutureInterfaceBasePrivate::QFutureInterfaceBasePrivate(QFutureInterfaceBase::State initialState) : refCount(1), m_progressValue(0), m_progressMinimum(0), m_progressMaximum(0), state(initialState), pendingResults(0), diff --git a/src/corelib/concurrent/qfutureinterface.h b/src/corelib/concurrent/qfutureinterface.h index 30bfbdb..dfe7941 100644 --- a/src/corelib/concurrent/qfutureinterface.h +++ b/src/corelib/concurrent/qfutureinterface.h @@ -132,6 +132,8 @@ public: protected: bool referenceCountIsOne() const; + bool refT() const; + bool derefT() const; public: #ifndef QFUTURE_TEST @@ -150,13 +152,17 @@ class QFutureInterface : public QFutureInterfaceBase public: QFutureInterface(State initialState = NoState) : QFutureInterfaceBase(initialState) - { } + { + refT(); + } QFutureInterface(const QFutureInterface &other) : QFutureInterfaceBase(other) - { } + { + refT(); + } ~QFutureInterface() { - if (referenceCountIsOne()) + if (!derefT()) resultStore().clear(); } @@ -165,7 +171,8 @@ public: QFutureInterface &operator=(const QFutureInterface &other) { - if (referenceCountIsOne()) + other.refT(); + if (!derefT()) resultStore().clear(); QFutureInterfaceBase::operator=(other); return *this; diff --git a/src/corelib/concurrent/qfutureinterface_p.h b/src/corelib/concurrent/qfutureinterface_p.h index 407c926..8431b1a 100644 --- a/src/corelib/concurrent/qfutureinterface_p.h +++ b/src/corelib/concurrent/qfutureinterface_p.h @@ -129,7 +129,31 @@ class QFutureInterfaceBasePrivate public: QFutureInterfaceBasePrivate(QFutureInterfaceBase::State initialState); - QAtomicInt refCount; + // When the last QFuture reference is removed, we need to make + // sure that data stored in the ResultStore is cleaned out. + // Since QFutureInterfaceBasePrivate can be shared between QFuture + // and QFuture objects, we use a separate ref. counter + // to keep track of QFuture objects. + class RefCount + { + public: + inline RefCount(int r = 0, int rt = 0) + : m_refCount(r), m_refCountT(rt) {} + // Default ref counter for QFIBP + inline bool ref() { return m_refCount.ref(); } + inline bool deref() { return m_refCount.deref(); } + // Ref counter for type T + inline bool refT() { return m_refCountT.ref(); } + inline bool derefT() { return m_refCountT.deref(); } + inline operator int() const { return int(m_refCount); } + inline bool operator==(int value) const { return m_refCount == value; } + + private: + QAtomicInt m_refCount; + QAtomicInt m_refCountT; + }; + + RefCount refCount; mutable QMutex m_mutex; QWaitCondition waitCondition; QList outputConnections; diff --git a/tests/auto/qfuture/tst_qfuture.cpp b/tests/auto/qfuture/tst_qfuture.cpp index f6ed5a9..0f1836c 100644 --- a/tests/auto/qfuture/tst_qfuture.cpp +++ b/tests/auto/qfuture/tst_qfuture.cpp @@ -1282,18 +1282,32 @@ void tst_QFuture::throttling() void tst_QFuture::voidConversions() { - QFutureInterface iface; - iface.reportStarted(); + { + QFutureInterface iface; + iface.reportStarted(); - QFuture intFuture(&iface); + QFuture intFuture(&iface); + int value = 10; + iface.reportFinished(&value); - int value = 10; - iface.reportFinished(&value); + QFuture voidFuture(intFuture); + voidFuture = intFuture; + + QVERIFY(voidFuture == intFuture); + } - QFuture voidFuture(intFuture); - voidFuture = intFuture; + { + QFuture voidFuture; + { + QFutureInterface > iface; + iface.reportStarted(); - QVERIFY(voidFuture == intFuture); + QFuture > listFuture(&iface); + iface.reportResult(QList() << 1 << 2 << 3); + voidFuture = listFuture; + } + QCOMPARE(voidFuture.resultCount(), 0); + } } diff --git a/tests/auto/qtconcurrentmap/tst_qtconcurrentmap.cpp b/tests/auto/qtconcurrentmap/tst_qtconcurrentmap.cpp index 43075f1..f8c4a36 100644 --- a/tests/auto/qtconcurrentmap/tst_qtconcurrentmap.cpp +++ b/tests/auto/qtconcurrentmap/tst_qtconcurrentmap.cpp @@ -43,6 +43,7 @@ #include #include +#include #include @@ -76,6 +77,7 @@ private slots: void stlContainers(); void qFutureAssignmentLeak(); void stressTest(); + void persistentResultTest(); public slots: void throttling(); }; @@ -2416,6 +2418,47 @@ void tst_QtConcurrentMap::stressTest() } } +struct LockedCounter +{ + LockedCounter(QMutex *mutex, QAtomicInt *ai) + : mtx(mutex), + ref(ai) {} + + typedef int result_type; + int operator()(int x) + { + QMutexLocker locker(mtx); + ref->ref(); + return ++x; + } + + QMutex *mtx; + QAtomicInt *ref; +}; + +// The Thread engine holds the last reference +// to the QFuture, so this should not leak +// or fail. +void tst_QtConcurrentMap::persistentResultTest() +{ + QFuture voidFuture; + QMutex mtx; + QAtomicInt ref; + LockedCounter lc(&mtx, &ref); + QList list; + { + list << 1 << 2 << 3; + mtx.lock(); + QFuture future = QtConcurrent::mapped(list + ,lc); + voidFuture = future; + } + QCOMPARE(int(ref), 0); + mtx.unlock(); // Unblock + voidFuture.waitForFinished(); + QCOMPARE(int(ref), 3); +} + QTEST_MAIN(tst_QtConcurrentMap) #else -- cgit v0.12