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29 #include "Assertions.h"
31 #include "HandleHeap.h"
36 HandleSlot allocateGlobalHandle(JSGlobalData&);
38 // A strongly referenced handle that prevents the object it points to from being garbage collected.
39 template <typename T> class Strong : public Handle<T> {
40 using Handle<T>::slot;
41 using Handle<T>::setSlot;
44 typedef typename Handle<T>::ExternalType ExternalType;
51 Strong(JSGlobalData& globalData, ExternalType value = ExternalType())
52 : Handle<T>(allocateGlobalHandle(globalData))
57 Strong(JSGlobalData& globalData, Handle<T> handle)
58 : Handle<T>(allocateGlobalHandle(globalData))
63 Strong(const Strong& other)
68 setSlot(HandleHeap::heapFor(other.slot())->allocate());
72 template <typename U> Strong(const Strong<U>& other)
77 setSlot(HandleHeap::heapFor(other.slot())->allocate());
81 enum HashTableDeletedValueTag { HashTableDeletedValue };
82 bool isHashTableDeletedValue() const { return slot() == hashTableDeletedValue(); }
83 Strong(HashTableDeletedValueTag)
84 : Handle<T>(hashTableDeletedValue())
93 void swap(Strong& other)
95 Handle<T>::swap(other);
98 void set(JSGlobalData& globalData, ExternalType value)
101 setSlot(allocateGlobalHandle(globalData));
105 template <typename U> Strong& operator=(const Strong<U>& other)
112 set(*HandleHeap::heapFor(other.slot())->globalData(), other.get());
116 Strong& operator=(const Strong& other)
123 set(*HandleHeap::heapFor(other.slot())->globalData(), other.get());
131 HandleHeap::heapFor(slot())->deallocate(slot());
136 static HandleSlot hashTableDeletedValue() { return reinterpret_cast<HandleSlot>(-1); }
138 void set(ExternalType externalType)
141 JSValue value = HandleTypes<T>::toJSValue(externalType);
142 HandleHeap::heapFor(slot())->writeBarrier(slot(), value);
147 template<class T> inline void swap(Strong<T>& a, Strong<T>& b)
156 template<typename T> struct VectorTraits<JSC::Strong<T> > : SimpleClassVectorTraits {
157 static const bool canCompareWithMemcmp = false;
160 template<typename P> struct HashTraits<JSC::Strong<P> > : SimpleClassHashTraits<JSC::Strong<P> > { };