QMutexLocker: add move semantics

The class is similar to unique_lock in that it allows for unlocking
and relocking. Since the locked state is tracked by QMutexLocker itself,
it's trivial to make it movable.

[ChangeLog][QtCore][QMutexLocker] The class is now movable.

Change-Id: I534044f8024575e996c12efb2236761d493798a3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Marc Mutz <marc.mutz@qt.io>

1 files changed, 67 insertions, 0 deletions

diff --git a/tests/auto/corelib/thread/qmutexlocker/tst_qmutexlocker.cpp b/tests/auto/corelib/thread/qmutexlocker/tst_qmutexlocker.cpp
index 29c8b92222..8844dd5624 100644
--- a/tests/auto/corelib/thread/qmutexlocker/tst_qmutexlocker.cpp
+++ b/tests/auto/corelib/thread/qmutexlocker/tst_qmutexlocker.cpp
@@ -67,6 +67,7 @@ private slots:
     void scopeTest();
     void unlockAndRelockTest();
     void lockerStateTest();
+    void moveSemantics();
 };
 
 void tst_QMutexLocker::scopeTest()
@@ -214,5 +215,71 @@ void tst_QMutexLocker::lockerStateTest()
     thread = nullptr;
 }
 
+void tst_QMutexLocker::moveSemantics()
+{
+    {
+        QMutexLocker<QMutex> locker(nullptr);
+        QVERIFY(!locker.isLocked());
+        QCOMPARE(locker.mutex(), nullptr);
+
+        QMutexLocker locker2(std::move(locker));
+        QVERIFY(!locker.isLocked());
+        QVERIFY(!locker2.isLocked());
+        QCOMPARE(locker.mutex(), nullptr);
+        QCOMPARE(locker2.mutex(), nullptr);
+    }
+
+    QMutex mutex;
+
+    {
+        QMutexLocker locker(&mutex);
+        QVERIFY(locker.isLocked());
+        QCOMPARE(locker.mutex(), &mutex);
+        QVERIFY(!mutex.tryLock());
+
+        QMutexLocker locker2(std::move(locker));
+        QVERIFY(!locker.isLocked());
+        QVERIFY(locker2.isLocked());
+        QCOMPARE(locker.mutex(), nullptr);
+        QCOMPARE(locker2.mutex(), &mutex);
+        QVERIFY(!mutex.tryLock());
+    }
+
+    QVERIFY(mutex.tryLock());
+    mutex.unlock();
+
+    {
+        QMutex mutex;
+        QMutexLocker locker(&mutex);
+        QVERIFY(locker.isLocked());
+        QCOMPARE(locker.mutex(), &mutex);
+        QVERIFY(!mutex.tryLock());
+
+        locker.unlock();
+        QVERIFY(!locker.isLocked());
+        QCOMPARE(locker.mutex(), &mutex);
+        QVERIFY(mutex.tryLock());
+        mutex.unlock();
+
+        QMutexLocker locker2(std::move(locker));
+        QVERIFY(!locker.isLocked());
+        QVERIFY(!locker2.isLocked());
+        QCOMPARE(locker.mutex(), nullptr);
+        QCOMPARE(locker2.mutex(), &mutex);
+        QVERIFY(mutex.tryLock());
+        mutex.unlock();
+
+        locker2.relock();
+        QVERIFY(!locker.isLocked());
+        QVERIFY(locker2.isLocked());
+        QCOMPARE(locker.mutex(), nullptr);
+        QCOMPARE(locker2.mutex(), &mutex);
+        QVERIFY(!mutex.tryLock());
+    }
+
+    QVERIFY(mutex.tryLock());
+    mutex.unlock();
+}
+
 QTEST_MAIN(tst_QMutexLocker)
 #include "tst_qmutexlocker.moc"