Use QElapsedTimer instead of QTime to measure elapsed time

Getting the current time from QTime is expensive as it adheres
to the locale timezone. To measure elapsed time in a code block,
using the monotonic QElapsedTimer is much faster.

Change-Id: Ibea390d7bc5270a20cf35111dfc919e37be7001e
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 4 insertions, 5 deletions

diff --git a/src/qml/memory/qv4mm.cpp b/src/qml/memory/qv4mm.cpp
index 4592dd5c9b..2588d8db00 100644
--- a/src/qml/memory/qv4mm.cpp
+++ b/src/qml/memory/qv4mm.cpp
@@ -40,7 +40,7 @@
 #include "PageAllocation.h"
 #include "StdLibExtras.h"
 
-#include <QTime>
+#include <QElapsedTimer>
 #include <QMap>
 #include <QScopedValueRollback>
 
@@ -562,18 +562,17 @@ void MemoryManager::runGC()
     } else {
         const size_t totalMem = getAllocatedMem();
 
-        QTime t;
+        QElapsedTimer t;
         t.start();
         mark();
-        int markTime = t.elapsed();
-        t.restart();
+        qint64 markTime = t.restart();
         const size_t usedBefore = getUsedMem();
         const size_t largeItemsBefore = getLargeItemsMem();
         int chunksBefore = m_d->heapChunks.size();
         sweep();
         const size_t usedAfter = getUsedMem();
         const size_t largeItemsAfter = getLargeItemsMem();
-        int sweepTime = t.elapsed();
+        qint64 sweepTime = t.elapsed();
 
         qDebug() << "========== GC ==========";
         qDebug() << "Marked object in" << markTime << "ms.";