1 // Copyright 2018 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_OBJECTS_PROTOTYPE_INFO_H_ 6 #define V8_OBJECTS_PROTOTYPE_INFO_H_ 7 8 #include "src/objects/fixed-array.h" 9 #include "src/objects/objects.h" 10 #include "src/objects/struct.h" 11 #include "torque-generated/bit-fields.h" 12 13 // Has to be the last include (doesn't have include guards): 14 #include "src/objects/object-macros.h" 15 16 namespace v8 { 17 namespace internal { 18 19 #include "torque-generated/src/objects/prototype-info-tq.inc" 20 21 // Container for metadata stored on each prototype map. 22 class PrototypeInfo 23 : public TorqueGeneratedPrototypeInfo<PrototypeInfo, Struct> { 24 public: 25 static const int UNREGISTERED = -1; 26 27 // [object_create_map]: A field caching the map for Object.create(prototype). 28 static inline void SetObjectCreateMap(Handle<PrototypeInfo> info, 29 Handle<Map> map); 30 inline Map ObjectCreateMap(); 31 inline bool HasObjectCreateMap(); 32 33 DECL_BOOLEAN_ACCESSORS(should_be_fast_map) 34 35 // Dispatched behavior. 36 DECL_PRINTER(PrototypeInfo) 37 DECL_VERIFIER(PrototypeInfo) 38 39 // Bit field usage. 40 DEFINE_TORQUE_GENERATED_PROTOTYPE_INFO_FLAGS() 41 42 class BodyDescriptor; 43 44 TQ_OBJECT_CONSTRUCTORS(PrototypeInfo) 45 }; 46 47 // A growing array with an additional API for marking slots "empty". When adding 48 // new elements, we reuse the empty slots instead of growing the array. 49 class V8_EXPORT_PRIVATE PrototypeUsers : public WeakArrayList { 50 public: 51 static Handle<WeakArrayList> Add(Isolate* isolate, 52 Handle<WeakArrayList> array, 53 Handle<Map> value, int* assigned_index); 54 55 static inline void MarkSlotEmpty(WeakArrayList array, int index); 56 57 // The callback is called when a weak pointer to HeapObject "object" is moved 58 // from index "from_index" to index "to_index" during compaction. The callback 59 // must not cause GC. 60 using CompactionCallback = void (*)(HeapObject object, int from_index, 61 int to_index); 62 static WeakArrayList Compact( 63 Handle<WeakArrayList> array, Heap* heap, CompactionCallback callback, 64 AllocationType allocation = AllocationType::kYoung); 65 66 #ifdef VERIFY_HEAP 67 static void Verify(WeakArrayList array); 68 #endif // VERIFY_HEAP 69 70 static const int kEmptySlotIndex = 0; 71 static const int kFirstIndex = 1; 72 73 static const int kNoEmptySlotsMarker = 0; 74 75 private: 76 static inline Smi empty_slot_index(WeakArrayList array); 77 static inline void set_empty_slot_index(WeakArrayList array, int index); 78 79 static void ScanForEmptySlots(WeakArrayList array); 80 81 DISALLOW_IMPLICIT_CONSTRUCTORS(PrototypeUsers); 82 }; 83 84 } // namespace internal 85 } // namespace v8 86 87 #include "src/objects/object-macros-undef.h" 88 89 #endif // V8_OBJECTS_PROTOTYPE_INFO_H_ 90