Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1 | // Copyright 2012 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_VISITING_H_ |
| 6 | #define V8_OBJECTS_VISITING_H_ |
| 7 | |
| 8 | #include "src/allocation.h" |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 9 | #include "src/heap/heap.h" |
| 10 | #include "src/heap/spaces.h" |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 11 | #include "src/layout-descriptor.h" |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 12 | #include "src/objects-body-descriptors.h" |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 13 | |
| 14 | // This file provides base classes and auxiliary methods for defining |
| 15 | // static object visitors used during GC. |
| 16 | // Visiting HeapObject body with a normal ObjectVisitor requires performing |
| 17 | // two switches on object's instance type to determine object size and layout |
| 18 | // and one or more virtual method calls on visitor itself. |
| 19 | // Static visitor is different: it provides a dispatch table which contains |
| 20 | // pointers to specialized visit functions. Each map has the visitor_id |
| 21 | // field which contains an index of specialized visitor to use. |
| 22 | |
| 23 | namespace v8 { |
| 24 | namespace internal { |
| 25 | |
| 26 | |
| 27 | // Base class for all static visitors. |
| 28 | class StaticVisitorBase : public AllStatic { |
| 29 | public: |
| 30 | #define VISITOR_ID_LIST(V) \ |
| 31 | V(SeqOneByteString) \ |
| 32 | V(SeqTwoByteString) \ |
| 33 | V(ShortcutCandidate) \ |
| 34 | V(ByteArray) \ |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 35 | V(BytecodeArray) \ |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 36 | V(FreeSpace) \ |
| 37 | V(FixedArray) \ |
| 38 | V(FixedDoubleArray) \ |
| 39 | V(FixedTypedArray) \ |
| 40 | V(FixedFloat64Array) \ |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 41 | V(NativeContext) \ |
| 42 | V(AllocationSite) \ |
| 43 | V(DataObject2) \ |
| 44 | V(DataObject3) \ |
| 45 | V(DataObject4) \ |
| 46 | V(DataObject5) \ |
| 47 | V(DataObject6) \ |
| 48 | V(DataObject7) \ |
| 49 | V(DataObject8) \ |
| 50 | V(DataObject9) \ |
| 51 | V(DataObjectGeneric) \ |
| 52 | V(JSObject2) \ |
| 53 | V(JSObject3) \ |
| 54 | V(JSObject4) \ |
| 55 | V(JSObject5) \ |
| 56 | V(JSObject6) \ |
| 57 | V(JSObject7) \ |
| 58 | V(JSObject8) \ |
| 59 | V(JSObject9) \ |
| 60 | V(JSObjectGeneric) \ |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 61 | V(JSApiObject2) \ |
| 62 | V(JSApiObject3) \ |
| 63 | V(JSApiObject4) \ |
| 64 | V(JSApiObject5) \ |
| 65 | V(JSApiObject6) \ |
| 66 | V(JSApiObject7) \ |
| 67 | V(JSApiObject8) \ |
| 68 | V(JSApiObject9) \ |
| 69 | V(JSApiObjectGeneric) \ |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 70 | V(Struct2) \ |
| 71 | V(Struct3) \ |
| 72 | V(Struct4) \ |
| 73 | V(Struct5) \ |
| 74 | V(Struct6) \ |
| 75 | V(Struct7) \ |
| 76 | V(Struct8) \ |
| 77 | V(Struct9) \ |
| 78 | V(StructGeneric) \ |
| 79 | V(ConsString) \ |
| 80 | V(SlicedString) \ |
| 81 | V(Symbol) \ |
| 82 | V(Oddball) \ |
| 83 | V(Code) \ |
| 84 | V(Map) \ |
| 85 | V(Cell) \ |
| 86 | V(PropertyCell) \ |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 87 | V(WeakCell) \ |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 88 | V(TransitionArray) \ |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 89 | V(SharedFunctionInfo) \ |
| 90 | V(JSFunction) \ |
| 91 | V(JSWeakCollection) \ |
| 92 | V(JSArrayBuffer) \ |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 93 | V(JSRegExp) |
| 94 | |
| 95 | // For data objects, JS objects and structs along with generic visitor which |
| 96 | // can visit object of any size we provide visitors specialized by |
| 97 | // object size in words. |
| 98 | // Ids of specialized visitors are declared in a linear order (without |
| 99 | // holes) starting from the id of visitor specialized for 2 words objects |
| 100 | // (base visitor id) and ending with the id of generic visitor. |
| 101 | // Method GetVisitorIdForSize depends on this ordering to calculate visitor |
| 102 | // id of specialized visitor from given instance size, base visitor id and |
| 103 | // generic visitor's id. |
| 104 | enum VisitorId { |
| 105 | #define VISITOR_ID_ENUM_DECL(id) kVisit##id, |
| 106 | VISITOR_ID_LIST(VISITOR_ID_ENUM_DECL) |
| 107 | #undef VISITOR_ID_ENUM_DECL |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 108 | kVisitorIdCount, |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 109 | kVisitDataObject = kVisitDataObject2, |
| 110 | kVisitJSObject = kVisitJSObject2, |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 111 | kVisitJSApiObject = kVisitJSApiObject2, |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 112 | kVisitStruct = kVisitStruct2, |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 113 | }; |
| 114 | |
| 115 | // Visitor ID should fit in one byte. |
| 116 | STATIC_ASSERT(kVisitorIdCount <= 256); |
| 117 | |
| 118 | // Determine which specialized visitor should be used for given instance type |
| 119 | // and instance type. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 120 | static VisitorId GetVisitorId(int instance_type, int instance_size, |
| 121 | bool has_unboxed_fields); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 122 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 123 | // Determine which specialized visitor should be used for given map. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 124 | static VisitorId GetVisitorId(Map* map); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 125 | |
| 126 | // For visitors that allow specialization by size calculate VisitorId based |
| 127 | // on size, base visitor id and generic visitor id. |
| 128 | static VisitorId GetVisitorIdForSize(VisitorId base, VisitorId generic, |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 129 | int object_size, |
| 130 | bool has_unboxed_fields) { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 131 | DCHECK((base == kVisitDataObject) || (base == kVisitStruct) || |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 132 | (base == kVisitJSObject) || (base == kVisitJSApiObject)); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 133 | DCHECK(IsAligned(object_size, kPointerSize)); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 134 | DCHECK(Heap::kMinObjectSizeInWords * kPointerSize <= object_size); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 135 | DCHECK(object_size <= Page::kMaxRegularHeapObjectSize); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 136 | DCHECK(!has_unboxed_fields || (base == kVisitJSObject) || |
| 137 | (base == kVisitJSApiObject)); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 138 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 139 | if (has_unboxed_fields) return generic; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 140 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 141 | int visitor_id = Min( |
| 142 | base + (object_size >> kPointerSizeLog2) - Heap::kMinObjectSizeInWords, |
| 143 | static_cast<int>(generic)); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 144 | |
| 145 | return static_cast<VisitorId>(visitor_id); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 146 | } |
| 147 | }; |
| 148 | |
| 149 | |
| 150 | template <typename Callback> |
| 151 | class VisitorDispatchTable { |
| 152 | public: |
| 153 | void CopyFrom(VisitorDispatchTable* other) { |
| 154 | // We are not using memcpy to guarantee that during update |
| 155 | // every element of callbacks_ array will remain correct |
| 156 | // pointer (memcpy might be implemented as a byte copying loop). |
| 157 | for (int i = 0; i < StaticVisitorBase::kVisitorIdCount; i++) { |
| 158 | base::NoBarrier_Store(&callbacks_[i], other->callbacks_[i]); |
| 159 | } |
| 160 | } |
| 161 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 162 | inline Callback GetVisitor(Map* map); |
| 163 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 164 | inline Callback GetVisitorById(StaticVisitorBase::VisitorId id) { |
| 165 | return reinterpret_cast<Callback>(callbacks_[id]); |
| 166 | } |
| 167 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 168 | void Register(StaticVisitorBase::VisitorId id, Callback callback) { |
| 169 | DCHECK(id < StaticVisitorBase::kVisitorIdCount); // id is unsigned. |
| 170 | callbacks_[id] = reinterpret_cast<base::AtomicWord>(callback); |
| 171 | } |
| 172 | |
| 173 | template <typename Visitor, StaticVisitorBase::VisitorId base, |
| 174 | StaticVisitorBase::VisitorId generic, int object_size_in_words> |
| 175 | void RegisterSpecialization() { |
| 176 | static const int size = object_size_in_words * kPointerSize; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 177 | Register(StaticVisitorBase::GetVisitorIdForSize(base, generic, size, false), |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 178 | &Visitor::template VisitSpecialized<size>); |
| 179 | } |
| 180 | |
| 181 | |
| 182 | template <typename Visitor, StaticVisitorBase::VisitorId base, |
| 183 | StaticVisitorBase::VisitorId generic> |
| 184 | void RegisterSpecializations() { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 185 | STATIC_ASSERT((generic - base + Heap::kMinObjectSizeInWords) == 10); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 186 | RegisterSpecialization<Visitor, base, generic, 2>(); |
| 187 | RegisterSpecialization<Visitor, base, generic, 3>(); |
| 188 | RegisterSpecialization<Visitor, base, generic, 4>(); |
| 189 | RegisterSpecialization<Visitor, base, generic, 5>(); |
| 190 | RegisterSpecialization<Visitor, base, generic, 6>(); |
| 191 | RegisterSpecialization<Visitor, base, generic, 7>(); |
| 192 | RegisterSpecialization<Visitor, base, generic, 8>(); |
| 193 | RegisterSpecialization<Visitor, base, generic, 9>(); |
| 194 | Register(generic, &Visitor::Visit); |
| 195 | } |
| 196 | |
| 197 | private: |
| 198 | base::AtomicWord callbacks_[StaticVisitorBase::kVisitorIdCount]; |
| 199 | }; |
| 200 | |
| 201 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 202 | template <typename StaticVisitor, typename BodyDescriptor, typename ReturnType> |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 203 | class FlexibleBodyVisitor : public AllStatic { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 204 | public: |
| 205 | INLINE(static ReturnType Visit(Map* map, HeapObject* object)) { |
| 206 | int object_size = BodyDescriptor::SizeOf(map, object); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 207 | BodyDescriptor::template IterateBody<StaticVisitor>(object, object_size); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 208 | return static_cast<ReturnType>(object_size); |
| 209 | } |
| 210 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 211 | // This specialization is only suitable for objects containing pointer fields. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 212 | template <int object_size> |
| 213 | static inline ReturnType VisitSpecialized(Map* map, HeapObject* object) { |
| 214 | DCHECK(BodyDescriptor::SizeOf(map, object) == object_size); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 215 | DCHECK(!FLAG_unbox_double_fields || map->HasFastPointerLayout()); |
| 216 | StaticVisitor::VisitPointers( |
| 217 | object->GetHeap(), object, |
| 218 | HeapObject::RawField(object, BodyDescriptor::kStartOffset), |
| 219 | HeapObject::RawField(object, object_size)); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 220 | return static_cast<ReturnType>(object_size); |
| 221 | } |
| 222 | }; |
| 223 | |
| 224 | |
| 225 | template <typename StaticVisitor, typename BodyDescriptor, typename ReturnType> |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 226 | class FixedBodyVisitor : public AllStatic { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 227 | public: |
| 228 | INLINE(static ReturnType Visit(Map* map, HeapObject* object)) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 229 | BodyDescriptor::template IterateBody<StaticVisitor>(object); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 230 | return static_cast<ReturnType>(BodyDescriptor::kSize); |
| 231 | } |
| 232 | }; |
| 233 | |
| 234 | |
| 235 | // Base class for visitors used for a linear new space iteration. |
| 236 | // IterateBody returns size of visited object. |
| 237 | // Certain types of objects (i.e. Code objects) are not handled |
| 238 | // by dispatch table of this visitor because they cannot appear |
| 239 | // in the new space. |
| 240 | // |
| 241 | // This class is intended to be used in the following way: |
| 242 | // |
| 243 | // class SomeVisitor : public StaticNewSpaceVisitor<SomeVisitor> { |
| 244 | // ... |
| 245 | // } |
| 246 | // |
| 247 | // This is an example of Curiously recurring template pattern |
| 248 | // (see http://en.wikipedia.org/wiki/Curiously_recurring_template_pattern). |
| 249 | // We use CRTP to guarantee aggressive compile time optimizations (i.e. |
| 250 | // inlining and specialization of StaticVisitor::VisitPointers methods). |
| 251 | template <typename StaticVisitor> |
| 252 | class StaticNewSpaceVisitor : public StaticVisitorBase { |
| 253 | public: |
| 254 | static void Initialize(); |
| 255 | |
| 256 | INLINE(static int IterateBody(Map* map, HeapObject* obj)) { |
| 257 | return table_.GetVisitor(map)(map, obj); |
| 258 | } |
| 259 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 260 | INLINE(static void VisitPointers(Heap* heap, HeapObject* object, |
| 261 | Object** start, Object** end)) { |
| 262 | for (Object** p = start; p < end; p++) { |
| 263 | StaticVisitor::VisitPointer(heap, object, p); |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | // Although we are using the JSFunction body descriptor which does not |
| 268 | // visit the code entry, compiler wants it to be accessible. |
| 269 | // See JSFunction::BodyDescriptorImpl. |
| 270 | INLINE(static void VisitCodeEntry(Heap* heap, HeapObject* object, |
| 271 | Address entry_address)) { |
| 272 | UNREACHABLE(); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 273 | } |
| 274 | |
| 275 | private: |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 276 | INLINE(static int VisitByteArray(Map* map, HeapObject* object)) { |
| 277 | return reinterpret_cast<ByteArray*>(object)->ByteArraySize(); |
| 278 | } |
| 279 | |
| 280 | INLINE(static int VisitFixedDoubleArray(Map* map, HeapObject* object)) { |
| 281 | int length = reinterpret_cast<FixedDoubleArray*>(object)->length(); |
| 282 | return FixedDoubleArray::SizeFor(length); |
| 283 | } |
| 284 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 285 | INLINE(static int VisitJSObject(Map* map, HeapObject* object)) { |
| 286 | return JSObjectVisitor::Visit(map, object); |
| 287 | } |
| 288 | |
| 289 | INLINE(static int VisitSeqOneByteString(Map* map, HeapObject* object)) { |
| 290 | return SeqOneByteString::cast(object) |
| 291 | ->SeqOneByteStringSize(map->instance_type()); |
| 292 | } |
| 293 | |
| 294 | INLINE(static int VisitSeqTwoByteString(Map* map, HeapObject* object)) { |
| 295 | return SeqTwoByteString::cast(object) |
| 296 | ->SeqTwoByteStringSize(map->instance_type()); |
| 297 | } |
| 298 | |
| 299 | INLINE(static int VisitFreeSpace(Map* map, HeapObject* object)) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 300 | return FreeSpace::cast(object)->size(); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 301 | } |
| 302 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 303 | INLINE(static int VisitBytecodeArray(Map* map, HeapObject* object)); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 304 | |
| 305 | class DataObjectVisitor { |
| 306 | public: |
| 307 | template <int object_size> |
| 308 | static inline int VisitSpecialized(Map* map, HeapObject* object) { |
| 309 | return object_size; |
| 310 | } |
| 311 | |
| 312 | INLINE(static int Visit(Map* map, HeapObject* object)) { |
| 313 | return map->instance_size(); |
| 314 | } |
| 315 | }; |
| 316 | |
| 317 | typedef FlexibleBodyVisitor<StaticVisitor, StructBodyDescriptor, int> |
| 318 | StructVisitor; |
| 319 | |
| 320 | typedef FlexibleBodyVisitor<StaticVisitor, JSObject::BodyDescriptor, int> |
| 321 | JSObjectVisitor; |
| 322 | |
| 323 | typedef int (*Callback)(Map* map, HeapObject* object); |
| 324 | |
| 325 | static VisitorDispatchTable<Callback> table_; |
| 326 | }; |
| 327 | |
| 328 | |
| 329 | template <typename StaticVisitor> |
| 330 | VisitorDispatchTable<typename StaticNewSpaceVisitor<StaticVisitor>::Callback> |
| 331 | StaticNewSpaceVisitor<StaticVisitor>::table_; |
| 332 | |
| 333 | |
| 334 | // Base class for visitors used to transitively mark the entire heap. |
| 335 | // IterateBody returns nothing. |
| 336 | // Certain types of objects might not be handled by this base class and |
| 337 | // no visitor function is registered by the generic initialization. A |
| 338 | // specialized visitor function needs to be provided by the inheriting |
| 339 | // class itself for those cases. |
| 340 | // |
| 341 | // This class is intended to be used in the following way: |
| 342 | // |
| 343 | // class SomeVisitor : public StaticMarkingVisitor<SomeVisitor> { |
| 344 | // ... |
| 345 | // } |
| 346 | // |
| 347 | // This is an example of Curiously recurring template pattern. |
| 348 | template <typename StaticVisitor> |
| 349 | class StaticMarkingVisitor : public StaticVisitorBase { |
| 350 | public: |
| 351 | static void Initialize(); |
| 352 | |
| 353 | INLINE(static void IterateBody(Map* map, HeapObject* obj)) { |
| 354 | table_.GetVisitor(map)(map, obj); |
| 355 | } |
| 356 | |
| 357 | INLINE(static void VisitPropertyCell(Map* map, HeapObject* object)); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 358 | INLINE(static void VisitWeakCell(Map* map, HeapObject* object)); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 359 | INLINE(static void VisitTransitionArray(Map* map, HeapObject* object)); |
| 360 | INLINE(static void VisitCodeEntry(Heap* heap, HeapObject* object, |
| 361 | Address entry_address)); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 362 | INLINE(static void VisitEmbeddedPointer(Heap* heap, RelocInfo* rinfo)); |
| 363 | INLINE(static void VisitCell(Heap* heap, RelocInfo* rinfo)); |
| 364 | INLINE(static void VisitDebugTarget(Heap* heap, RelocInfo* rinfo)); |
| 365 | INLINE(static void VisitCodeTarget(Heap* heap, RelocInfo* rinfo)); |
| 366 | INLINE(static void VisitCodeAgeSequence(Heap* heap, RelocInfo* rinfo)); |
| 367 | INLINE(static void VisitExternalReference(RelocInfo* rinfo)) {} |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 368 | INLINE(static void VisitInternalReference(RelocInfo* rinfo)) {} |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 369 | INLINE(static void VisitRuntimeEntry(RelocInfo* rinfo)) {} |
| 370 | // Skip the weak next code link in a code object. |
| 371 | INLINE(static void VisitNextCodeLink(Heap* heap, Object** slot)) {} |
| 372 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 373 | protected: |
| 374 | INLINE(static void VisitMap(Map* map, HeapObject* object)); |
| 375 | INLINE(static void VisitCode(Map* map, HeapObject* object)); |
| 376 | INLINE(static void VisitSharedFunctionInfo(Map* map, HeapObject* object)); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 377 | INLINE(static void VisitAllocationSite(Map* map, HeapObject* object)); |
| 378 | INLINE(static void VisitWeakCollection(Map* map, HeapObject* object)); |
| 379 | INLINE(static void VisitJSFunction(Map* map, HeapObject* object)); |
| 380 | INLINE(static void VisitJSRegExp(Map* map, HeapObject* object)); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 381 | INLINE(static void VisitNativeContext(Map* map, HeapObject* object)); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 382 | INLINE(static void VisitBytecodeArray(Map* map, HeapObject* object)); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 383 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 384 | // Mark pointers in a Map treating some elements of the descriptor array weak. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 385 | static void MarkMapContents(Heap* heap, Map* map); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 386 | |
| 387 | // Code flushing support. |
| 388 | INLINE(static bool IsFlushable(Heap* heap, JSFunction* function)); |
| 389 | INLINE(static bool IsFlushable(Heap* heap, SharedFunctionInfo* shared_info)); |
| 390 | |
| 391 | // Helpers used by code flushing support that visit pointer fields and treat |
| 392 | // references to code objects either strongly or weakly. |
| 393 | static void VisitSharedFunctionInfoStrongCode(Heap* heap, HeapObject* object); |
| 394 | static void VisitSharedFunctionInfoWeakCode(Heap* heap, HeapObject* object); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 395 | static void VisitJSFunctionStrongCode(Map* map, HeapObject* object); |
| 396 | static void VisitJSFunctionWeakCode(Map* map, HeapObject* object); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 397 | |
| 398 | class DataObjectVisitor { |
| 399 | public: |
| 400 | template <int size> |
| 401 | static inline void VisitSpecialized(Map* map, HeapObject* object) {} |
| 402 | |
| 403 | INLINE(static void Visit(Map* map, HeapObject* object)) {} |
| 404 | }; |
| 405 | |
| 406 | typedef FlexibleBodyVisitor<StaticVisitor, FixedArray::BodyDescriptor, void> |
| 407 | FixedArrayVisitor; |
| 408 | |
| 409 | typedef FlexibleBodyVisitor<StaticVisitor, JSObject::BodyDescriptor, void> |
| 410 | JSObjectVisitor; |
| 411 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 412 | class JSApiObjectVisitor : AllStatic { |
| 413 | public: |
| 414 | template <int size> |
| 415 | static inline void VisitSpecialized(Map* map, HeapObject* object) { |
| 416 | TracePossibleWrapper(object); |
| 417 | JSObjectVisitor::template VisitSpecialized<size>(map, object); |
| 418 | } |
| 419 | |
| 420 | INLINE(static void Visit(Map* map, HeapObject* object)) { |
| 421 | TracePossibleWrapper(object); |
| 422 | JSObjectVisitor::Visit(map, object); |
| 423 | } |
| 424 | |
| 425 | private: |
| 426 | INLINE(static void TracePossibleWrapper(HeapObject* object)) { |
| 427 | if (object->GetHeap()->UsingEmbedderHeapTracer()) { |
| 428 | DCHECK(object->IsJSObject()); |
| 429 | object->GetHeap()->TracePossibleWrapper(JSObject::cast(object)); |
| 430 | } |
| 431 | } |
| 432 | }; |
| 433 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 434 | typedef FlexibleBodyVisitor<StaticVisitor, StructBodyDescriptor, void> |
| 435 | StructObjectVisitor; |
| 436 | |
| 437 | typedef void (*Callback)(Map* map, HeapObject* object); |
| 438 | |
| 439 | static VisitorDispatchTable<Callback> table_; |
| 440 | }; |
| 441 | |
| 442 | |
| 443 | template <typename StaticVisitor> |
| 444 | VisitorDispatchTable<typename StaticMarkingVisitor<StaticVisitor>::Callback> |
| 445 | StaticMarkingVisitor<StaticVisitor>::table_; |
| 446 | |
| 447 | |
| 448 | class WeakObjectRetainer; |
| 449 | |
| 450 | |
| 451 | // A weak list is single linked list where each element has a weak pointer to |
| 452 | // the next element. Given the head of the list, this function removes dead |
| 453 | // elements from the list and if requested records slots for next-element |
| 454 | // pointers. The template parameter T is a WeakListVisitor that defines how to |
| 455 | // access the next-element pointers. |
| 456 | template <class T> |
| 457 | Object* VisitWeakList(Heap* heap, Object* list, WeakObjectRetainer* retainer); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 458 | } // namespace internal |
| 459 | } // namespace v8 |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 460 | |
| 461 | #endif // V8_OBJECTS_VISITING_H_ |