Implement support for WeakMap

Change-Id: Id23e80fe5918ba7dc897568123bf3db4d35e9092
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

2 files changed, 22 insertions, 0 deletions

diff --git a/src/qml/memory/qv4mm.cpp b/src/qml/memory/qv4mm.cpp
index 258fac57af..065204b5d3 100644
--- a/src/qml/memory/qv4mm.cpp
+++ b/src/qml/memory/qv4mm.cpp
@@ -61,6 +61,7 @@
 #include <algorithm>
 #include "qv4alloca_p.h"
 #include "qv4profiling_p.h"
+#include "qv4mapobject_p.h"
 
 //#define MM_STATS
 
@@ -976,6 +977,18 @@ void MemoryManager::sweep(bool lastSweep, ClassDestroyStatsCallback classCountPt
         (*it) = Primitive::undefinedValue();
     }
 
+    // remove objects from weak maps and sets
+    Heap::MapObject *map = weakMaps;
+    Heap::MapObject **lastMap = &weakMaps;
+    while (map) {
+        if (map->isMarked()) {
+            map->removeUnmarkedKeys();
+            *lastMap = map;
+            lastMap = &map->nextWeakMap;
+        }
+        map = map->nextWeakMap;
+    }
+
     // onDestruction handlers may have accessed other QObject wrappers and reset their value, so ensure
     // that they are all set to undefined.
     for (PersistentValueStorage::Iterator it = m_weakValues->begin(); it != m_weakValues->end(); ++it) {
@@ -1179,6 +1192,12 @@ size_t MemoryManager::getLargeItemsMem() const
     return hugeItemAllocator.usedMem();
 }
 
+void MemoryManager::registerWeakMap(Heap::MapObject *map)
+{
+    map->nextWeakMap = weakMaps;
+    weakMaps = map;
+}
+
 MemoryManager::~MemoryManager()
 {
     delete m_persistentValues;
diff --git a/src/qml/memory/qv4mm_p.h b/src/qml/memory/qv4mm_p.h
index e3a011caf9..da162d2dfe 100644
--- a/src/qml/memory/qv4mm_p.h
+++ b/src/qml/memory/qv4mm_p.h
@@ -274,6 +274,8 @@ public:
         return static_cast<typename ManagedType::Data *>(b);
     }
 
+    void registerWeakMap(Heap::MapObject *map);
+
 protected:
     /// expects size to be aligned
     Heap::Base *allocString(std::size_t unmanagedSize);
@@ -296,6 +298,7 @@ public:
     PersistentValueStorage *m_persistentValues;
     PersistentValueStorage *m_weakValues;
     QVector<Value *> m_pendingFreedObjectWrapperValue;
+    Heap::MapObject *weakMaps = nullptr;
 
     std::size_t unmanagedHeapSize = 0; // the amount of bytes of heap that is not managed by the memory manager, but which is held onto by managed items.
     std::size_t unmanagedHeapSizeGCLimit;