1 files changed, 164 insertions, 0 deletions
diff --git a/tests/auto/corelib/tools/qatomicscopedvaluerollback/tst_qatomicscopedvaluerollback.cpp b/tests/auto/corelib/tools/qatomicscopedvaluerollback/tst_qatomicscopedvaluerollback.cpp
new file mode 100644
index 0000000000..89bd1d7ff6
--- /dev/null
+++ b/tests/auto/corelib/tools/qatomicscopedvaluerollback/tst_qatomicscopedvaluerollback.cpp
@@ -0,0 +1,164 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#include <QtCore/qatomicscopedvaluerollback.h>
+
+#include <QTest>
+
+class tst_QAtomicScopedValueRollback : public QObject
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void leavingScope();
+    void leavingScopeAfterCommit();
+    void rollbackToPreviousCommit();
+    void exceptions();
+    void earlyExitScope();
+private:
+    void earlyExitScope_helper(int exitpoint, std::atomic<int> &member);
+};
+
+void tst_QAtomicScopedValueRollback::leavingScope()
+{
+    QAtomicInt i = 0;
+    QBasicAtomicInteger<bool> b = false;
+    std::atomic<bool> b2 = false;
+    int x = 0, y = 42;
+    QBasicAtomicPointer<int> p = &x;
+
+    //test rollback on going out of scope
+    {
+        QAtomicScopedValueRollback ri(i);
+        QAtomicScopedValueRollback rb(b);
+        QAtomicScopedValueRollback rb2(b2, true);
+        QAtomicScopedValueRollback rp(p);
+        QCOMPARE(b.loadRelaxed(), false);
+        QCOMPARE(b2, true);
+        QCOMPARE(i.loadRelaxed(), 0);
+        QCOMPARE(p.loadRelaxed(), &x);
+        b.storeRelaxed(true);
+        i.storeRelaxed(1);
+        p.storeRelaxed(&y);
+        QCOMPARE(b.loadRelaxed(), true);
+        QCOMPARE(i.loadRelaxed(), 1);
+        QCOMPARE(p.loadRelaxed(), &y);
+    }
+    QCOMPARE(b.loadRelaxed(), false);
+    QCOMPARE(b2, false);
+    QCOMPARE(i.loadRelaxed(), 0);
+    QCOMPARE(p.loadRelaxed(), &x);
+}
+
+void tst_QAtomicScopedValueRollback::leavingScopeAfterCommit()
+{
+    std::atomic<int> i = 0;
+    QAtomicInteger<bool> b = false;
+
+    //test rollback on going out of scope
+    {
+        QAtomicScopedValueRollback ri(i);
+        QAtomicScopedValueRollback rb(b);
+        QCOMPARE(b.loadRelaxed(), false);
+        QCOMPARE(i, 0);
+        b.storeRelaxed(true);
+        i = 1;
+        QCOMPARE(b.loadRelaxed(), true);
+        QCOMPARE(i, 1);
+        ri.commit();
+        rb.commit();
+    }
+    QCOMPARE(b.loadRelaxed(), true);
+    QCOMPARE(i, 1);
+}
+
+void tst_QAtomicScopedValueRollback::rollbackToPreviousCommit()
+{
+    QBasicAtomicInt i = 0;
+    {
+        QAtomicScopedValueRollback ri(i);
+        i++;
+        ri.commit();
+        i++;
+    }
+    QCOMPARE(i.loadRelaxed(), 1);
+    {
+        QAtomicScopedValueRollback ri1(i);
+        i++;
+        ri1.commit();
+        i++;
+        ri1.commit();
+        i++;
+    }
+    QCOMPARE(i.loadRelaxed(), 3);
+}
+
+void tst_QAtomicScopedValueRollback::exceptions()
+{
+    std::atomic<bool> b = false;
+    bool caught = false;
+    QT_TRY
+    {
+        QAtomicScopedValueRollback rb(b);
+        b = true;
+        QT_THROW(std::bad_alloc()); //if Qt compiled without exceptions this is noop
+        rb.commit(); //if Qt compiled without exceptions, true is committed
+    }
+    QT_CATCH(...)
+    {
+        caught = true;
+    }
+    QCOMPARE(b, !caught); //expect false if exception was thrown, true otherwise
+}
+
+void tst_QAtomicScopedValueRollback::earlyExitScope()
+{
+    QAtomicInt ai = 0;
+    std::atomic<int> aj = 0;
+    while (true) {
+        QAtomicScopedValueRollback ri(ai);
+        ++ai;
+        aj = ai.loadRelaxed();
+        if (ai.loadRelaxed() > 8) break;
+        ri.commit();
+    }
+    QCOMPARE(ai.loadRelaxed(), 8);
+    QCOMPARE(aj.load(), 9);
+
+    for (int i = 0; i < 5; ++i) {
+        aj = 1;
+        earlyExitScope_helper(i, aj);
+        QCOMPARE(aj.load(), 1 << i);
+    }
+}
+
+static void operator*=(std::atomic<int> &lhs, int rhs)
+{
+    int expected = lhs.load();
+    while (!lhs.compare_exchange_weak(expected, expected * rhs))
+        ;
+}
+
+void tst_QAtomicScopedValueRollback::earlyExitScope_helper(int exitpoint, std::atomic<int>& member)
+{
+    QAtomicScopedValueRollback r(member);
+    member *= 2;
+    if (exitpoint == 0)
+        return;
+    r.commit();
+    member *= 2;
+    if (exitpoint == 1)
+        return;
+    r.commit();
+    member *= 2;
+    if (exitpoint == 2)
+        return;
+    r.commit();
+    member *= 2;
+    if (exitpoint == 3)
+        return;
+    r.commit();
+}
+
+QTEST_MAIN(tst_QAtomicScopedValueRollback)
+#include "tst_qatomicscopedvaluerollback.moc"