HandleManager: do not allow counter to overflow

This could otherwise have happened if an element was acquired and released
repeatedly.

Change-Id: I29a327f32fdd9d9a02460bff26c9ff56fdd3dd61
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

1 files changed, 101 insertions, 1 deletions

diff --git a/tests/auto/core/handlemanager/tst_handlemanager.cpp b/tests/auto/core/handlemanager/tst_handlemanager.cpp
index a60d3cc57..3198b54a9 100644
--- a/tests/auto/core/handlemanager/tst_handlemanager.cpp
+++ b/tests/auto/core/handlemanager/tst_handlemanager.cpp
@@ -47,6 +47,7 @@ private slots:
     void updateChangesValue();
     void resetRemovesAllEntries();
     void maximumEntries();
+    void checkNoCounterOverflow();
 };
 
 class SimpleResource
@@ -63,61 +64,83 @@ typedef Qt3DCore::QHandle<SimpleResource> Handle;
 
 void tst_HandleManager::construction()
 {
+    // GIVEN
     Qt3DCore::QHandleManager<SimpleResource> manager;
+
+    // THEN
     QVERIFY(manager.activeEntries() == 0);
 }
 
 void tst_HandleManager::correctPointer()
 {
+    // GIVEN
     Qt3DCore::QHandleManager<SimpleResource> manager;
     SimpleResource *p1 = (SimpleResource *)0xdeadbeef;
+
+    // WHEN
     const Handle h = manager.acquire(p1);
 
     bool ok = false;
     SimpleResource *p2 = manager.data(h, &ok);
+
+    // THEN
     QVERIFY(ok == true);
     QVERIFY(p1 == p2);
 }
 
 void tst_HandleManager::correctPointers()
 {
+    // GIVEN
     Qt3DCore::QHandleManager<SimpleResource> manager;
     SimpleResource *p[3];
     p[0] = (SimpleResource *)0xdeadbeef;
     p[1] = (SimpleResource *)0x11111111;
     p[2] = (SimpleResource *)0x22222222;
 
+    // WHEN
     for (int i = 0; i < 3; ++i) {
+        // WHEN
         const Handle h = manager.acquire(p[i]);
 
         bool ok = false;
         SimpleResource *q = manager.data(h, &ok);
+
+        // THEN
         QVERIFY(ok == true);
         QVERIFY(p[i] == q);
     }
 
+    // THEN
     QVERIFY(manager.activeEntries() == 3);
 }
 
 void tst_HandleManager::correctConstPointer()
 {
+    // GIVEN
     Qt3DCore::QHandleManager<SimpleResource> manager;
     QSharedPointer<SimpleResource> p1(new SimpleResource);
     const Handle h = manager.acquire(p1.data());
 
+    // WHEN
     bool ok = false;
     const SimpleResource *p2 = manager.constData(h, &ok);
+
+    // THEN
     QVERIFY(ok == true);
     QVERIFY(p1.data() == p2);
 }
 
 void tst_HandleManager::nullForRemovedEntry()
 {
+    // GIVEN
     Qt3DCore::QHandleManager<SimpleResource> manager;
     QSharedPointer<SimpleResource> p1(new SimpleResource);
     const Handle h = manager.acquire(p1.data());
+
+    // WHEN
     manager.release(h);
 
+    // THEN
     bool ok = false;
     SimpleResource *p2 = manager.data(h, &ok);
     QVERIFY(ok == false);
@@ -126,44 +149,67 @@ void tst_HandleManager::nullForRemovedEntry()
 
 void tst_HandleManager::validHandleForReplacementEntry()
 {
+    // GIVEN
     Qt3DCore::QHandleManager<SimpleResource> manager;
     QSharedPointer<SimpleResource> p1(new SimpleResource);
     const Handle h = manager.acquire(p1.data());
+
+    // THEN
     QVERIFY(manager.activeEntries() == 1);
+
+    // WHEN
     manager.release(h);
+
+    // THEN
     QVERIFY(manager.activeEntries() == 0);
 
+    // WHEN
     QSharedPointer<SimpleResource> p2(new SimpleResource);
     const Handle h2 = manager.acquire(p2.data());
+
+    // THEN
     QVERIFY(h2.isNull() == false);
     QVERIFY(h2.counter() == 2);
     QVERIFY(manager.activeEntries() == 1);
 
+    // WHEN
     bool ok = false;
     SimpleResource *p3 = manager.data(h2, &ok);
+
+    // THEN
     QVERIFY(ok == true);
     QVERIFY(p3 == p2);
 }
 
 void tst_HandleManager::updateChangesValue()
 {
+    // GIVEN
     Qt3DCore::QHandleManager<SimpleResource> manager;
     QSharedPointer<SimpleResource> p1(new SimpleResource);
     const Handle h = manager.acquire(p1.data());
 
+    // WHEN
     QSharedPointer<SimpleResource> p2(new SimpleResource);
     manager.update(h, p2.data());
+
+    // THEN
     QVERIFY(manager.activeEntries() == 1);
 
+    // WHEN
     bool ok = false;
     SimpleResource *p3 = manager.data(h, &ok);
+
+    // THEN
     QVERIFY(ok == true);
     QVERIFY(p3 == p2);
 }
 
 void tst_HandleManager::resetRemovesAllEntries()
 {
+    // GIVEN
     Qt3DCore::QHandleManager<SimpleResource> manager;
+
+    // WHEN
     for (int i = 0; i < 100; ++i) {
         SimpleResource *p = (SimpleResource *) 0xdead0000 + i;
         const Handle h = manager.acquire(p);
@@ -174,18 +220,25 @@ void tst_HandleManager::resetRemovesAllEntries()
         QVERIFY(p == q);
     }
 
+    // THEN
     QVERIFY(manager.activeEntries() == 100);
 
+    // WHEN
     manager.reset();
+
+    // THEN
     QVERIFY(manager.activeEntries() == 0);
 }
 
 void tst_HandleManager::maximumEntries()
 {
+    // GIVEN
     Qt3DCore::QHandleManager<SimpleResource> manager;
 
+    // THEN
     QCOMPARE(Handle::maxIndex(), (uint)((1 << 16) - 1));
 
+    // WHEN
     for (int i = 0; i < (int)Handle::maxIndex(); ++i) {
         SimpleResource *p = (SimpleResource *) 0xdead0000 + i;
         const Handle h = manager.acquire(p);
@@ -196,11 +249,58 @@ void tst_HandleManager::maximumEntries()
         QVERIFY(p == q);
     }
 
-    QVERIFY(manager.activeEntries() == Handle::maxIndex());
+    // THEN
+    QVERIFY(manager.activeEntries() == Handle::maxIndex());\
+
+    // WHEN
     manager.reset();
+
+    // THEN
     QVERIFY(manager.activeEntries() == 0);
 }
 
+void tst_HandleManager::checkNoCounterOverflow()
+{
+    // GIVEN
+    const int indexBits = 16;
+    Qt3DCore::QHandleManager<SimpleResource, indexBits> manager;
+    SimpleResource *p = (SimpleResource *) 0xdead0000;
+    Qt3DCore::QHandle<SimpleResource, indexBits> h = manager.acquire(p);
+
+    // THEN
+    QCOMPARE(h.maxCounter(), (quint32)((1 << (32 - indexBits - 2)) - 1));
+    QCOMPARE(h.counter(), (quint32)1);
+
+    // WHEN
+    const quint32 maxIterations = h.maxCounter() - 2;
+    const quint32 handleIndex = h.index();
+
+    qDebug() << maxIterations << handleIndex;
+
+    // Acquire and release maxIteration time to increase counter
+    for (quint32 i = 0; i < maxIterations; ++i) {
+        // WHEN
+        manager.release(h);
+        h = manager.acquire(p);
+
+        // THEN
+        QCOMPARE(h.index(), handleIndex);
+        QCOMPARE(h.counter(), i + 2);
+    }
+
+    // THEN
+    QCOMPARE(h.counter(), h.maxCounter() - 1);
+
+    // WHEN
+    manager.release(h);
+    h = manager.acquire(p);
+
+    // THEN
+    QCOMPARE(h.counter(), (quint32)1);
+}
+
+
+
 QTEST_APPLESS_MAIN(tst_HandleManager)
 
 #include "tst_handlemanager.moc"