Fix issue with allocating huge objects in the memory manager

We shouldn't allocate objects that are larger than the size of
a standard memory segment through the chunk allocator, as this
can lead to problems when freeing the segment and then re-using
it again.

Instead allocate a private MemorySegment for these objects, and
free it when the object gets garbage collected.

Task-number: QTBUG-66732
Change-Id: Ic24ff65d204977f313ab0adaf7a8132883e525f0
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/qml/memory/qv4mm_p.h b/src/qml/memory/qv4mm_p.h
index 1ef54ffcc6..40670bcdc7 100644
--- a/src/qml/memory/qv4mm_p.h
+++ b/src/qml/memory/qv4mm_p.h
@@ -69,6 +69,7 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 
 struct ChunkAllocator;
+struct MemorySegment;
 
 struct BlockAllocator {
     BlockAllocator(ChunkAllocator *chunkAllocator, ExecutionEngine *engine)
@@ -136,6 +137,7 @@ struct HugeItemAllocator {
     ChunkAllocator *chunkAllocator;
     ExecutionEngine *engine;
     struct HugeChunk {
+        MemorySegment *segment;
         Chunk *chunk;
         size_t size;
     };