diff options
author | Thiago Macieira <thiago.macieira@intel.com> | 2020-06-26 09:50:09 -0700 |
---|---|---|
committer | Qt Cherry-pick Bot <cherrypick_bot@qt-project.org> | 2020-07-31 20:33:32 +0000 |
commit | 73d6c2058fcb23ec9d126b7f862cf588d31222af (patch) | |
tree | 288e3ac476b6afa81380ceadc25344de7b7102e1 | |
parent | 18df9b7309a64e6d2c864c140664523e60ba6e7d (diff) |
QSharedPointer: do allow calling deleters on null pointers
I don't know why std::shared_ptr allows this, but why not.
[ChangeLog][Important Behavior Changes] QSharedPointer objects will now
call custom deleters even when the pointer being tracked was null. This
behavior is the same as std::shared_ptr.
Fixes: QTBUG-85285
Change-Id: I24006db8360041f598c5fffd161c260df0313b55
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
(cherry picked from commit 95afe6b244dbd9623a92399d1bed0b9f52aa1e65)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
-rw-r--r-- | src/corelib/tools/qsharedpointer.cpp | 11 | ||||
-rw-r--r-- | src/corelib/tools/qsharedpointer_impl.h | 15 | ||||
-rw-r--r-- | tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp | 33 |
3 files changed, 46 insertions, 13 deletions
diff --git a/src/corelib/tools/qsharedpointer.cpp b/src/corelib/tools/qsharedpointer.cpp index 0576fb2bd0..a24b689181 100644 --- a/src/corelib/tools/qsharedpointer.cpp +++ b/src/corelib/tools/qsharedpointer.cpp @@ -1,7 +1,8 @@ /**************************************************************************** ** -** Copyright (C) 2016 The Qt Company Ltd. -** Copyright (C) 2016 Intel Corporation. +** Copyright (C) 2020 The Qt Company Ltd. +** Copyright (C) 2020 Intel Corporation. +** Copyright (C) 2019 Klarälvdalens Datakonsult AB. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the QtCore module of the Qt Toolkit. @@ -1562,6 +1563,12 @@ void QtSharedPointer::internalSafetyCheckAdd(const void *d_ptr, const volatile v if (!kp) return; // end-game: the application is being destroyed already + if (!ptr) { + // nullptr is allowed to be tracked by more than one QSharedPointer, so we + // need something else to put in our tracking structures + ptr = d_ptr; + } + QMutexLocker lock(&kp->mutex); Q_ASSERT(!kp->dPointers.contains(d_ptr)); diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h index 362d57fb9a..790c187cb9 100644 --- a/src/corelib/tools/qsharedpointer_impl.h +++ b/src/corelib/tools/qsharedpointer_impl.h @@ -1,7 +1,8 @@ /**************************************************************************** ** -** Copyright (C) 2016 The Qt Company Ltd. -** Copyright (C) 2016 Intel Corporation. +** Copyright (C) 2019 The Qt Company Ltd. +** Copyright (C) 2020 Intel Corporation. +** Copyright (C) 2019 Klarälvdalens Datakonsult AB. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the QtCore module of the Qt Toolkit. @@ -107,7 +108,7 @@ namespace QtSharedPointer { template <class T, typename Klass, typename RetVal> inline void executeDeleter(T *t, RetVal (Klass:: *memberDeleter)()) - { (t->*memberDeleter)(); } + { if (t) (t->*memberDeleter)(); } template <class T, typename Deleter> inline void executeDeleter(T *t, Deleter d) { d(t); } @@ -319,7 +320,8 @@ public: { internalConstruct(ptr, deleter); } template <typename Deleter> - QSharedPointer(std::nullptr_t, Deleter) : value(nullptr), d(nullptr) { } + QSharedPointer(std::nullptr_t, Deleter deleter) : value(nullptr) + { internalConstruct(static_cast<T *>(nullptr), deleter); } QSharedPointer(const QSharedPointer &other) noexcept : value(other.value), d(other.d) { if (d) ref(); } @@ -470,11 +472,6 @@ private: template <typename X, typename Deleter> inline void internalConstruct(X *ptr, Deleter deleter) { - if (!ptr) { - d = nullptr; - return; - } - typedef QtSharedPointer::ExternalRefCountWithCustomDeleter<X, Deleter> Private; # ifdef QT_SHAREDPOINTER_TRACK_POINTERS typename Private::DestroyerFn actualDeleter = &Private::safetyCheckDeleter; diff --git a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp index a9fd282ac9..9dd9f114f9 100644 --- a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp +++ b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp @@ -1,7 +1,8 @@ /**************************************************************************** ** -** Copyright (C) 2016 The Qt Company Ltd. -** Copyright (C) 2016 Intel Corporation. +** Copyright (C) 2019 The Qt Company Ltd. +** Copyright (C) 2020 Intel Corporation. +** Copyright (C) 2019 Klarälvdalens Datakonsult AB. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the test suite of the Qt Toolkit. @@ -95,6 +96,7 @@ private slots: void constCorrectness(); void customDeleter(); void lambdaCustomDeleter(); + void customDeleterOnNullptr(); void creating(); void creatingCvQualified(); void creatingVariadic(); @@ -1846,6 +1848,33 @@ void tst_QSharedPointer::lambdaCustomDeleter() safetyCheck(); } +void tst_QSharedPointer::customDeleterOnNullptr() +{ + Data *null = nullptr; + int callCount = 0; + auto deleter = [&callCount](Data *) { ++callCount; }; + { + QSharedPointer<Data> ptr(null, deleter); + } + safetyCheck(); + QCOMPARE(callCount, 1); + + callCount = 0; + { + QSharedPointer<Data> ptr(nullptr, deleter); + } + safetyCheck(); + QCOMPARE(callCount, 1); + + callCount = 0; + { + QSharedPointer<Data> ptr1(null, deleter); + QSharedPointer<Data> ptr2(nullptr, deleter); + } + safetyCheck(); + QCOMPARE(callCount, 2); +} + void customQObjectDeleterFn(QObject *obj) { ++customDeleterFnCallCount; |