Line data Source code
1 : // Copyright 2009 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 : #include "src/global-handles.h"
6 :
7 : #include "src/api-inl.h"
8 : #include "src/base/compiler-specific.h"
9 : #include "src/cancelable-task.h"
10 : #include "src/heap/embedder-tracing.h"
11 : #include "src/heap/heap-write-barrier-inl.h"
12 : #include "src/objects-inl.h"
13 : #include "src/objects/slots.h"
14 : #include "src/task-utils.h"
15 : #include "src/v8.h"
16 : #include "src/visitors.h"
17 : #include "src/vm-state-inl.h"
18 :
19 : namespace v8 {
20 : namespace internal {
21 :
22 : namespace {
23 :
24 : constexpr size_t kBlockSize = 256;
25 :
26 : } // namespace
27 :
28 : template <class _NodeType>
29 111704 : class GlobalHandles::NodeBlock final {
30 : public:
31 : using BlockType = NodeBlock<_NodeType>;
32 : using NodeType = _NodeType;
33 :
34 : V8_INLINE static NodeBlock* From(NodeType* node);
35 :
36 : NodeBlock(GlobalHandles* global_handles,
37 : GlobalHandles::NodeSpace<NodeType>* space,
38 : NodeBlock* next) V8_NOEXCEPT : next_(next),
39 : global_handles_(global_handles),
40 14353964 : space_(space) {}
41 :
42 170633280 : NodeType* at(size_t index) { return &nodes_[index]; }
43 : const NodeType* at(size_t index) const { return &nodes_[index]; }
44 : GlobalHandles::NodeSpace<NodeType>* space() const { return space_; }
45 : GlobalHandles* global_handles() const { return global_handles_; }
46 :
47 : V8_INLINE bool IncreaseUsage();
48 : V8_INLINE bool DecreaseUsage();
49 :
50 : V8_INLINE void ListAdd(NodeBlock** top);
51 : V8_INLINE void ListRemove(NodeBlock** top);
52 :
53 : NodeBlock* next() const { return next_; }
54 : NodeBlock* next_used() const { return next_used_; }
55 :
56 : private:
57 : NodeType nodes_[kBlockSize];
58 : NodeBlock* const next_;
59 : GlobalHandles* const global_handles_;
60 : GlobalHandles::NodeSpace<NodeType>* const space_;
61 : NodeBlock* next_used_ = nullptr;
62 : NodeBlock* prev_used_ = nullptr;
63 : uint32_t used_nodes_ = 0;
64 :
65 : DISALLOW_COPY_AND_ASSIGN(NodeBlock);
66 : };
67 :
68 : template <class NodeType>
69 : GlobalHandles::NodeBlock<NodeType>* GlobalHandles::NodeBlock<NodeType>::From(
70 : NodeType* node) {
71 : uintptr_t ptr =
72 20037505 : reinterpret_cast<uintptr_t>(node) - sizeof(NodeType) * node->index();
73 20037505 : BlockType* block = reinterpret_cast<BlockType*>(ptr);
74 : DCHECK_EQ(node, block->at(node->index()));
75 : return block;
76 : }
77 :
78 : template <class NodeType>
79 : bool GlobalHandles::NodeBlock<NodeType>::IncreaseUsage() {
80 : DCHECK_LT(used_nodes_, kBlockSize);
81 6978553 : return used_nodes_++ == 0;
82 : }
83 :
84 : template <class NodeType>
85 : void GlobalHandles::NodeBlock<NodeType>::ListAdd(BlockType** top) {
86 87215 : BlockType* old_top = *top;
87 87215 : *top = this;
88 87215 : next_used_ = old_top;
89 87215 : prev_used_ = nullptr;
90 87215 : if (old_top != nullptr) {
91 13533 : old_top->prev_used_ = this;
92 : }
93 : }
94 :
95 : template <class NodeType>
96 : bool GlobalHandles::NodeBlock<NodeType>::DecreaseUsage() {
97 : DCHECK_GT(used_nodes_, 0);
98 6529471 : return --used_nodes_ == 0;
99 : }
100 :
101 : template <class NodeType>
102 : void GlobalHandles::NodeBlock<NodeType>::ListRemove(BlockType** top) {
103 73176 : if (next_used_ != nullptr) next_used_->prev_used_ = prev_used_;
104 73176 : if (prev_used_ != nullptr) prev_used_->next_used_ = next_used_;
105 73176 : if (this == *top) {
106 68645 : *top = next_used_;
107 : }
108 : }
109 :
110 : template <class BlockType>
111 : class GlobalHandles::NodeIterator final {
112 : public:
113 : using NodeType = typename BlockType::NodeType;
114 :
115 : // Iterator traits.
116 : using iterator_category = std::forward_iterator_tag;
117 : using difference_type = std::ptrdiff_t;
118 : using value_type = NodeType*;
119 : using reference = value_type;
120 : using pointer = value_type*;
121 :
122 : explicit NodeIterator(BlockType* block) V8_NOEXCEPT : block_(block) {}
123 : NodeIterator(NodeIterator&& other) V8_NOEXCEPT : block_(other.block_),
124 : index_(other.index_) {}
125 :
126 : bool operator==(const NodeIterator& other) const {
127 : return block_ == other.block_;
128 : }
129 : bool operator!=(const NodeIterator& other) const {
130 : return block_ != other.block_;
131 : }
132 :
133 : NodeIterator& operator++() {
134 156335231 : if (++index_ < kBlockSize) return *this;
135 : index_ = 0;
136 : block_ = block_->next_used();
137 : return *this;
138 : }
139 :
140 : NodeType* operator*() { return block_->at(index_); }
141 : NodeType* operator->() { return block_->at(index_); }
142 :
143 : private:
144 : BlockType* block_ = nullptr;
145 : size_t index_ = 0;
146 :
147 : DISALLOW_COPY_AND_ASSIGN(NodeIterator);
148 : };
149 :
150 : template <class NodeType>
151 : class GlobalHandles::NodeSpace final {
152 : public:
153 : using BlockType = NodeBlock<NodeType>;
154 : using iterator = NodeIterator<BlockType>;
155 :
156 : static NodeSpace* From(NodeType* node);
157 : static void Release(NodeType* node);
158 :
159 : explicit NodeSpace(GlobalHandles* global_handles) V8_NOEXCEPT
160 124844 : : global_handles_(global_handles) {}
161 : ~NodeSpace();
162 :
163 : V8_INLINE NodeType* Acquire(Object object);
164 :
165 : iterator begin() { return iterator(first_used_block_); }
166 : iterator end() { return iterator(nullptr); }
167 :
168 : private:
169 : void PutNodesOnFreeList(BlockType* block);
170 : V8_INLINE void Free(NodeType* node);
171 :
172 : GlobalHandles* const global_handles_;
173 : BlockType* first_block_ = nullptr;
174 : BlockType* first_used_block_ = nullptr;
175 : NodeType* first_free_ = nullptr;
176 : };
177 :
178 : template <class NodeType>
179 124813 : GlobalHandles::NodeSpace<NodeType>::~NodeSpace() {
180 124813 : auto* block = first_block_;
181 180665 : while (block != nullptr) {
182 : auto* tmp = block->next();
183 111704 : delete block;
184 : block = tmp;
185 : }
186 124813 : }
187 :
188 : template <class NodeType>
189 : NodeType* GlobalHandles::NodeSpace<NodeType>::Acquire(Object object) {
190 6978553 : if (first_free_ == nullptr) {
191 111704 : first_block_ = new BlockType(global_handles_, this, first_block_);
192 : PutNodesOnFreeList(first_block_);
193 : }
194 : DCHECK_NOT_NULL(first_free_);
195 6978553 : NodeType* node = first_free_;
196 6978553 : first_free_ = first_free_->next_free();
197 : node->Acquire(object);
198 : BlockType* block = BlockType::From(node);
199 6978553 : if (block->IncreaseUsage()) {
200 : block->ListAdd(&first_used_block_);
201 : }
202 13957106 : global_handles_->isolate()->counters()->global_handles()->Increment();
203 6978555 : global_handles_->handles_count_++;
204 : DCHECK(node->IsInUse());
205 : return node;
206 : }
207 :
208 : template <class NodeType>
209 : void GlobalHandles::NodeSpace<NodeType>::PutNodesOnFreeList(BlockType* block) {
210 28652076 : for (int32_t i = kBlockSize - 1; i >= 0; --i) {
211 14298112 : NodeType* node = block->at(i);
212 : const uint8_t index = static_cast<uint8_t>(i);
213 : DCHECK_EQ(i, index);
214 : node->set_index(index);
215 14298112 : node->Free(first_free_);
216 14298112 : first_free_ = node;
217 : }
218 : }
219 :
220 : template <class NodeType>
221 6529471 : void GlobalHandles::NodeSpace<NodeType>::Release(NodeType* node) {
222 : BlockType* block = BlockType::From(node);
223 : block->space()->Free(node);
224 6529473 : }
225 :
226 : template <class NodeType>
227 : void GlobalHandles::NodeSpace<NodeType>::Free(NodeType* node) {
228 6529471 : node->Release(first_free_);
229 6529471 : first_free_ = node;
230 : BlockType* block = BlockType::From(node);
231 6529471 : if (block->DecreaseUsage()) {
232 : block->ListRemove(&first_used_block_);
233 : }
234 13058942 : global_handles_->isolate()->counters()->global_handles()->Decrement();
235 6529473 : global_handles_->handles_count_--;
236 : }
237 :
238 : template <class Child>
239 : class NodeBase {
240 : public:
241 : static Child* FromLocation(Address* location) {
242 : return reinterpret_cast<Child*>(location);
243 : }
244 :
245 : NodeBase() {
246 : DCHECK_EQ(offsetof(NodeBase, object_), 0);
247 : DCHECK_EQ(offsetof(NodeBase, class_id_), Internals::kNodeClassIdOffset);
248 : DCHECK_EQ(offsetof(NodeBase, flags_), Internals::kNodeFlagsOffset);
249 : }
250 :
251 : #ifdef ENABLE_HANDLE_ZAPPING
252 : ~NodeBase() {
253 : ClearFields();
254 14297777 : data_.next_free = nullptr;
255 14297777 : index_ = 0;
256 14297777 : }
257 : #endif
258 :
259 : void Free(Child* free_list) {
260 : ClearFields();
261 : AsChild()->MarkAsFree();
262 20827583 : data_.next_free = free_list;
263 : }
264 :
265 : void Acquire(Object object) {
266 : DCHECK(!AsChild()->IsInUse());
267 : CheckFieldsAreCleared();
268 6978553 : object_ = object.ptr();
269 : AsChild()->MarkAsUsed();
270 6978553 : data_.parameter = nullptr;
271 : DCHECK(AsChild()->IsInUse());
272 : }
273 :
274 6529471 : void Release(Child* free_list) {
275 : DCHECK(AsChild()->IsInUse());
276 : Free(free_list);
277 : DCHECK(!AsChild()->IsInUse());
278 6529471 : }
279 :
280 : Object object() const { return Object(object_); }
281 24433753 : FullObjectSlot location() { return FullObjectSlot(&object_); }
282 6978580 : Handle<Object> handle() { return Handle<Object>(&object_); }
283 :
284 10 : uint8_t index() const { return index_; }
285 14298112 : void set_index(uint8_t value) { index_ = value; }
286 :
287 : uint16_t wrapper_class_id() const { return class_id_; }
288 : bool has_wrapper_class_id() const {
289 : return class_id_ != v8::HeapProfiler::kPersistentHandleNoClassId;
290 : }
291 :
292 : // Accessors for next free node in the free list.
293 : Child* next_free() {
294 : DCHECK(!AsChild()->IsInUse());
295 : return data_.next_free;
296 : }
297 :
298 : void set_parameter(void* parameter) {
299 : DCHECK(AsChild()->IsInUse());
300 3673384 : data_.parameter = parameter;
301 : }
302 : void* parameter() const {
303 : DCHECK(AsChild()->IsInUse());
304 : return data_.parameter;
305 : }
306 :
307 : protected:
308 : Child* AsChild() { return reinterpret_cast<Child*>(this); }
309 : const Child* AsChild() const { return reinterpret_cast<const Child*>(this); }
310 :
311 : void ClearFields() {
312 : // Zap the values for eager trapping.
313 35125360 : object_ = kGlobalHandleZapValue;
314 35125360 : class_id_ = v8::HeapProfiler::kPersistentHandleNoClassId;
315 : AsChild()->ClearImplFields();
316 : }
317 :
318 : void CheckFieldsAreCleared() {
319 : DCHECK_EQ(kGlobalHandleZapValue, object_);
320 : DCHECK_EQ(v8::HeapProfiler::kPersistentHandleNoClassId, class_id_);
321 : AsChild()->CheckImplFieldsAreCleared();
322 : }
323 :
324 : // Storage for object pointer.
325 : //
326 : // Placed first to avoid offset computation. The stored data is equivalent to
327 : // an Object. It is stored as a plain Address for convenience (smallest number
328 : // of casts), and because it is a private implementation detail: the public
329 : // interface provides type safety.
330 : Address object_;
331 :
332 : // Class id set by the embedder.
333 : uint16_t class_id_;
334 :
335 : // Index in the containing handle block.
336 : uint8_t index_;
337 :
338 : uint8_t flags_;
339 :
340 : // The meaning of this field depends on node state:
341 : // - Node in free list: Stores next free node pointer.
342 : // - Otherwise, specific to the node implementation.
343 : union {
344 : Child* next_free;
345 : void* parameter;
346 : } data_;
347 : };
348 :
349 : namespace {
350 :
351 27 : void ExtractInternalFields(JSObject jsobject, void** embedder_fields, int len) {
352 27 : int field_count = jsobject->GetEmbedderFieldCount();
353 125 : for (int i = 0; i < len; ++i) {
354 54 : if (field_count == i) break;
355 : void* pointer;
356 49 : if (EmbedderDataSlot(jsobject, i).ToAlignedPointer(&pointer)) {
357 49 : embedder_fields[i] = pointer;
358 : }
359 : }
360 27 : }
361 :
362 : } // namespace
363 :
364 14279857 : class GlobalHandles::Node final : public NodeBase<GlobalHandles::Node> {
365 : public:
366 : // State transition diagram:
367 : // FREE -> NORMAL <-> WEAK -> PENDING -> NEAR_DEATH -> { NORMAL, WEAK, FREE }
368 : enum State {
369 : FREE = 0,
370 : NORMAL, // Normal global handle.
371 : WEAK, // Flagged as weak but not yet finalized.
372 : PENDING, // Has been recognized as only reachable by weak handles.
373 : NEAR_DEATH, // Callback has informed the handle is near death.
374 : NUMBER_OF_NODE_STATES
375 : };
376 :
377 : Node() {
378 : STATIC_ASSERT(static_cast<int>(NodeState::kMask) ==
379 : Internals::kNodeStateMask);
380 : STATIC_ASSERT(WEAK == Internals::kNodeStateIsWeakValue);
381 : STATIC_ASSERT(PENDING == Internals::kNodeStateIsPendingValue);
382 : STATIC_ASSERT(static_cast<int>(IsIndependent::kShift) ==
383 : Internals::kNodeIsIndependentShift);
384 : STATIC_ASSERT(static_cast<int>(IsActive::kShift) ==
385 : Internals::kNodeIsActiveShift);
386 : set_in_young_list(false);
387 : }
388 :
389 : void Zap() {
390 : DCHECK(IsInUse());
391 : // Zap the values for eager trapping.
392 : object_ = kGlobalHandleZapValue;
393 : }
394 :
395 : const char* label() const {
396 : return state() == NORMAL ? reinterpret_cast<char*>(data_.parameter)
397 10270652 : : nullptr;
398 : }
399 :
400 : // State and flag accessors.
401 :
402 : State state() const {
403 : return NodeState::decode(flags_);
404 : }
405 : void set_state(State state) {
406 51324819 : flags_ = NodeState::update(flags_, state);
407 : }
408 :
409 : bool is_independent() { return IsIndependent::decode(flags_); }
410 70178900 : void set_independent(bool v) { flags_ = IsIndependent::update(flags_, v); }
411 :
412 : bool is_active() {
413 : return IsActive::decode(flags_);
414 : }
415 : void set_active(bool v) {
416 45368214 : flags_ = IsActive::update(flags_, v);
417 : }
418 :
419 : bool is_in_young_list() const { return IsInYoungList::decode(flags_); }
420 38389505 : void set_in_young_list(bool v) { flags_ = IsInYoungList::update(flags_, v); }
421 :
422 : WeaknessType weakness_type() const {
423 : return NodeWeaknessType::decode(flags_);
424 : }
425 : void set_weakness_type(WeaknessType weakness_type) {
426 3652125 : flags_ = NodeWeaknessType::update(flags_, weakness_type);
427 : }
428 :
429 20 : bool IsWeak() const { return state() == WEAK; }
430 :
431 : bool IsInUse() const { return state() != FREE; }
432 :
433 : bool IsPhantomCallback() const {
434 3064243 : return weakness_type() == PHANTOM_WEAK ||
435 : weakness_type() == PHANTOM_WEAK_2_EMBEDDER_FIELDS;
436 : }
437 :
438 : bool IsPhantomResetHandle() const {
439 : return weakness_type() == PHANTOM_WEAK_RESET_HANDLE;
440 : }
441 :
442 : bool IsFinalizerHandle() const { return weakness_type() == FINALIZER_WEAK; }
443 :
444 : bool IsPendingPhantomCallback() const {
445 : return state() == PENDING && IsPhantomCallback();
446 : }
447 :
448 : bool IsPendingPhantomResetHandle() const {
449 : return state() == PENDING && IsPhantomResetHandle();
450 : }
451 :
452 : bool IsPendingFinalizer() const {
453 42208 : return state() == PENDING && weakness_type() == FINALIZER_WEAK;
454 : }
455 :
456 : bool IsPending() const { return state() == PENDING; }
457 :
458 : bool IsRetainer() const {
459 51676763 : return state() != FREE &&
460 3048779 : !(state() == NEAR_DEATH && weakness_type() != FINALIZER_WEAK);
461 : }
462 :
463 : bool IsStrongRetainer() const { return state() == NORMAL; }
464 :
465 : bool IsWeakRetainer() const {
466 48798403 : return state() == WEAK || state() == PENDING ||
467 0 : (state() == NEAR_DEATH && weakness_type() == FINALIZER_WEAK);
468 : }
469 :
470 : void MarkPending() {
471 : DCHECK(state() == WEAK);
472 : set_state(PENDING);
473 : }
474 :
475 : bool has_callback() const { return weak_callback_ != nullptr; }
476 :
477 : // Accessors for next free node in the free list.
478 : Node* next_free() {
479 : DCHECK_EQ(FREE, state());
480 : return data_.next_free;
481 : }
482 :
483 3652089 : void MakeWeak(void* parameter,
484 : WeakCallbackInfo<void>::Callback phantom_callback,
485 : v8::WeakCallbackType type) {
486 : DCHECK_NOT_NULL(phantom_callback);
487 : DCHECK(IsInUse());
488 3652089 : CHECK_NE(object_, kGlobalHandleZapValue);
489 : set_state(WEAK);
490 3652089 : switch (type) {
491 : case v8::WeakCallbackType::kParameter:
492 : set_weakness_type(PHANTOM_WEAK);
493 : break;
494 : case v8::WeakCallbackType::kInternalFields:
495 : set_weakness_type(PHANTOM_WEAK_2_EMBEDDER_FIELDS);
496 : break;
497 : case v8::WeakCallbackType::kFinalizer:
498 : set_weakness_type(FINALIZER_WEAK);
499 : break;
500 : }
501 : set_parameter(parameter);
502 3652089 : weak_callback_ = phantom_callback;
503 3652089 : }
504 :
505 36 : void MakeWeak(Address** location_addr) {
506 : DCHECK(IsInUse());
507 36 : CHECK_NE(object_, kGlobalHandleZapValue);
508 : set_state(WEAK);
509 : set_weakness_type(PHANTOM_WEAK_RESET_HANDLE);
510 : set_parameter(location_addr);
511 36 : weak_callback_ = nullptr;
512 36 : }
513 :
514 : void* ClearWeakness() {
515 : DCHECK(IsInUse());
516 : void* p = parameter();
517 : set_state(NORMAL);
518 : set_parameter(nullptr);
519 : return p;
520 : }
521 :
522 : void AnnotateStrongRetainer(const char* label) {
523 : DCHECK_EQ(state(), NORMAL);
524 2827990 : data_.parameter = const_cast<char*>(label);
525 : }
526 :
527 3056511 : void CollectPhantomCallbackData(
528 : std::vector<std::pair<Node*, PendingPhantomCallback>>*
529 : pending_phantom_callbacks) {
530 : DCHECK(weakness_type() == PHANTOM_WEAK ||
531 : weakness_type() == PHANTOM_WEAK_2_EMBEDDER_FIELDS);
532 : DCHECK(state() == PENDING);
533 : DCHECK_NOT_NULL(weak_callback_);
534 :
535 : void* embedder_fields[v8::kEmbedderFieldsInWeakCallback] = {nullptr,
536 3056511 : nullptr};
537 3056528 : if (weakness_type() != PHANTOM_WEAK && object()->IsJSObject()) {
538 : ExtractInternalFields(JSObject::cast(object()), embedder_fields,
539 17 : v8::kEmbedderFieldsInWeakCallback);
540 : }
541 :
542 : // Zap with something dangerous.
543 : location().store(Object(0xCA11));
544 :
545 3056511 : pending_phantom_callbacks->push_back(std::make_pair(
546 : this,
547 6113022 : PendingPhantomCallback(weak_callback_, parameter(), embedder_fields)));
548 : DCHECK(IsInUse());
549 : set_state(NEAR_DEATH);
550 3056511 : }
551 :
552 : void ResetPhantomHandle() {
553 : DCHECK_EQ(PHANTOM_WEAK_RESET_HANDLE, weakness_type());
554 : DCHECK_EQ(PENDING, state());
555 : DCHECK_NULL(weak_callback_);
556 : Address** handle = reinterpret_cast<Address**>(parameter());
557 31 : *handle = nullptr;
558 31 : NodeSpace<Node>::Release(this);
559 : }
560 :
561 21104 : void PostGarbageCollectionProcessing(Isolate* isolate) {
562 : // This method invokes a finalizer. Updating the method name would require
563 : // adjusting CFI blacklist as weak_callback_ is invoked on the wrong type.
564 21104 : CHECK(IsPendingFinalizer());
565 21104 : CHECK(!is_active());
566 : set_state(NEAR_DEATH);
567 : // Check that we are not passing a finalized external string to
568 : // the callback.
569 : DCHECK(!object()->IsExternalOneByteString() ||
570 : ExternalOneByteString::cast(object())->resource() != nullptr);
571 : DCHECK(!object()->IsExternalTwoByteString() ||
572 : ExternalTwoByteString::cast(object())->resource() != nullptr);
573 : // Leaving V8.
574 42208 : VMState<EXTERNAL> vmstate(isolate);
575 : HandleScope handle_scope(isolate);
576 : void* embedder_fields[v8::kEmbedderFieldsInWeakCallback] = {nullptr,
577 21104 : nullptr};
578 : v8::WeakCallbackInfo<void> data(reinterpret_cast<v8::Isolate*>(isolate),
579 : parameter(), embedder_fields, nullptr);
580 21104 : weak_callback_(data);
581 : // For finalizers the handle must have either been reset or made strong.
582 : // Both cases reset the state.
583 21104 : CHECK_NE(NEAR_DEATH, state());
584 21104 : }
585 :
586 : void MarkAsFree() { set_state(FREE); }
587 : void MarkAsUsed() { set_state(NORMAL); }
588 :
589 : GlobalHandles* global_handles() {
590 : return NodeBlock<Node>::From(this)->global_handles();
591 : }
592 :
593 : private:
594 : // Fields that are not used for managing node memory.
595 : void ClearImplFields() {
596 : set_independent(false);
597 : set_active(false);
598 35089450 : weak_callback_ = nullptr;
599 : }
600 :
601 : void CheckImplFieldsAreCleared() {
602 : DCHECK(!is_independent());
603 : DCHECK(!is_active());
604 : DCHECK_EQ(nullptr, weak_callback_);
605 : }
606 :
607 : // This stores three flags (independent, partially_dependent and
608 : // in_young_list) and a State.
609 : class NodeState : public BitField8<State, 0, 3> {};
610 : class IsIndependent : public BitField8<bool, NodeState::kNext, 1> {};
611 : // The following two fields are mutually exclusive
612 : class IsActive : public BitField8<bool, IsIndependent::kNext, 1> {};
613 : class IsInYoungList : public BitField8<bool, IsActive::kNext, 1> {};
614 : class NodeWeaknessType
615 : : public BitField8<WeaknessType, IsInYoungList::kNext, 2> {};
616 :
617 : // Handle specific callback - might be a weak reference in disguise.
618 : WeakCallbackInfo<void>::Callback weak_callback_;
619 :
620 : friend class NodeBase<Node>;
621 :
622 : DISALLOW_COPY_AND_ASSIGN(Node);
623 : };
624 :
625 17920 : class GlobalHandles::TracedNode final
626 : : public NodeBase<GlobalHandles::TracedNode> {
627 : public:
628 : TracedNode() { set_in_young_list(false); }
629 :
630 : enum State { FREE = 0, NORMAL, NEAR_DEATH };
631 :
632 : State state() const { return NodeState::decode(flags_); }
633 18150 : void set_state(State state) { flags_ = NodeState::update(flags_, state); }
634 :
635 : void MarkAsFree() { set_state(FREE); }
636 : void MarkAsUsed() { set_state(NORMAL); }
637 : bool IsInUse() const { return state() != FREE; }
638 : bool IsRetainer() const { return state() == NORMAL; }
639 : bool IsPhantomResetHandle() const { return callback_ == nullptr; }
640 :
641 : bool is_in_young_list() const { return IsInYoungList::decode(flags_); }
642 36011 : void set_in_young_list(bool v) { flags_ = IsInYoungList::update(flags_, v); }
643 :
644 : bool is_root() const { return IsRoot::decode(flags_); }
645 71850 : void set_root(bool v) { flags_ = IsRoot::update(flags_, v); }
646 :
647 : void SetFinalizationCallback(void* parameter,
648 : WeakCallbackInfo<void>::Callback callback) {
649 : set_parameter(parameter);
650 10 : callback_ = callback;
651 : }
652 : bool HasFinalizationCallback() const { return callback_ != nullptr; }
653 :
654 10 : void CollectPhantomCallbackData(
655 : std::vector<std::pair<TracedNode*, PendingPhantomCallback>>*
656 : pending_phantom_callbacks) {
657 : DCHECK(IsInUse());
658 : DCHECK_NOT_NULL(callback_);
659 :
660 : void* embedder_fields[v8::kEmbedderFieldsInWeakCallback] = {nullptr,
661 10 : nullptr};
662 : ExtractInternalFields(JSObject::cast(object()), embedder_fields,
663 10 : v8::kEmbedderFieldsInWeakCallback);
664 :
665 : // Zap with something dangerous.
666 : location().store(Object(0xCA11));
667 :
668 10 : pending_phantom_callbacks->push_back(std::make_pair(
669 20 : this, PendingPhantomCallback(callback_, parameter(), embedder_fields)));
670 : set_state(NEAR_DEATH);
671 10 : }
672 :
673 : void ResetPhantomHandle() {
674 : DCHECK(IsInUse());
675 20 : Address** handle = reinterpret_cast<Address**>(data_.parameter);
676 20 : *handle = nullptr;
677 20 : NodeSpace<TracedNode>::Release(this);
678 : DCHECK(!IsInUse());
679 : }
680 :
681 : protected:
682 : class NodeState : public BitField8<State, 0, 2> {};
683 : class IsInYoungList : public BitField8<bool, NodeState::kNext, 1> {};
684 : class IsRoot : public BitField8<bool, IsInYoungList::kNext, 1> {};
685 :
686 : void ClearImplFields() {
687 : set_root(true);
688 35910 : callback_ = nullptr;
689 : }
690 :
691 : void CheckImplFieldsAreCleared() const {
692 : DCHECK(is_root());
693 : DCHECK_NULL(callback_);
694 : }
695 :
696 : WeakCallbackInfo<void>::Callback callback_;
697 :
698 : friend class NodeBase<GlobalHandles::TracedNode>;
699 :
700 : DISALLOW_COPY_AND_ASSIGN(TracedNode);
701 : };
702 :
703 62422 : GlobalHandles::GlobalHandles(Isolate* isolate)
704 : : isolate_(isolate),
705 : regular_nodes_(new NodeSpace<GlobalHandles::Node>(this)),
706 249688 : traced_nodes_(new NodeSpace<GlobalHandles::TracedNode>(this)) {}
707 :
708 187218 : GlobalHandles::~GlobalHandles() { regular_nodes_.reset(nullptr); }
709 :
710 6978483 : Handle<Object> GlobalHandles::Create(Object value) {
711 6978485 : GlobalHandles::Node* result = regular_nodes_->Acquire(value);
712 10550306 : if (ObjectInYoungGeneration(value) && !result->is_in_young_list()) {
713 3411388 : young_nodes_.push_back(result);
714 3411388 : result->set_in_young_list(true);
715 : }
716 13956970 : return result->handle();
717 : }
718 :
719 3050030 : Handle<Object> GlobalHandles::Create(Address value) {
720 3050040 : return Create(Object(value));
721 : }
722 :
723 70 : Handle<Object> GlobalHandles::CreateTraced(Object value, Address* slot) {
724 70 : GlobalHandles::TracedNode* result = traced_nodes_->Acquire(value);
725 140 : if (ObjectInYoungGeneration(value) && !result->is_in_young_list()) {
726 70 : traced_young_nodes_.push_back(result);
727 70 : result->set_in_young_list(true);
728 : }
729 70 : result->set_parameter(slot);
730 70 : return result->handle();
731 : }
732 :
733 70 : Handle<Object> GlobalHandles::CreateTraced(Address value, Address* slot) {
734 70 : return CreateTraced(Object(value), slot);
735 : }
736 :
737 10 : Handle<Object> GlobalHandles::CopyGlobal(Address* location) {
738 : DCHECK_NOT_NULL(location);
739 : GlobalHandles* global_handles =
740 : Node::FromLocation(location)->global_handles();
741 : #ifdef VERIFY_HEAP
742 : if (i::FLAG_verify_heap) {
743 : Object(*location)->ObjectVerify(global_handles->isolate());
744 : }
745 : #endif // VERIFY_HEAP
746 20 : return global_handles->Create(*location);
747 : }
748 :
749 5836 : void GlobalHandles::MoveGlobal(Address** from, Address** to) {
750 : DCHECK_NOT_NULL(*from);
751 : DCHECK_NOT_NULL(*to);
752 : DCHECK_EQ(*from, *to);
753 5836 : Node* node = Node::FromLocation(*from);
754 5841 : if (node->IsWeak() && node->IsPhantomResetHandle()) {
755 : node->set_parameter(to);
756 : }
757 :
758 : // - Strong handles do not require fixups.
759 : // - Weak handles with finalizers and callbacks are too general to fix up. For
760 : // those the callers need to ensure consistency.
761 5836 : }
762 :
763 55 : void GlobalHandles::MoveTracedGlobal(Address** from, Address** to) {
764 : DCHECK_NOT_NULL(*from);
765 : DCHECK_NOT_NULL(*to);
766 : DCHECK_EQ(*from, *to);
767 55 : TracedNode* node = TracedNode::FromLocation(*from);
768 : // Only set the backpointer for clearing a phantom handle when there is no
769 : // finalization callback attached. As soon as a callback is attached to a node
770 : // the embedder is on its own when resetting a handle.
771 55 : if (!node->HasFinalizationCallback()) {
772 : node->set_parameter(to);
773 : }
774 55 : }
775 :
776 6529370 : void GlobalHandles::Destroy(Address* location) {
777 6529370 : if (location != nullptr) {
778 6529370 : NodeSpace<Node>::Release(Node::FromLocation(location));
779 : }
780 6529372 : }
781 :
782 50 : void GlobalHandles::DestroyTraced(Address* location) {
783 50 : if (location != nullptr) {
784 50 : NodeSpace<TracedNode>::Release(TracedNode::FromLocation(location));
785 : }
786 50 : }
787 :
788 10 : void GlobalHandles::SetFinalizationCallbackForTraced(
789 : Address* location, void* parameter,
790 : WeakCallbackInfo<void>::Callback callback) {
791 : TracedNode::FromLocation(location)->SetFinalizationCallback(parameter,
792 : callback);
793 10 : }
794 :
795 : typedef v8::WeakCallbackInfo<void>::Callback GenericCallback;
796 :
797 3652089 : void GlobalHandles::MakeWeak(Address* location, void* parameter,
798 : GenericCallback phantom_callback,
799 : v8::WeakCallbackType type) {
800 3652089 : Node::FromLocation(location)->MakeWeak(parameter, phantom_callback, type);
801 3652090 : }
802 :
803 36 : void GlobalHandles::MakeWeak(Address** location_addr) {
804 36 : Node::FromLocation(*location_addr)->MakeWeak(location_addr);
805 36 : }
806 :
807 21119 : void* GlobalHandles::ClearWeakness(Address* location) {
808 21119 : return Node::FromLocation(location)->ClearWeakness();
809 : }
810 :
811 2827990 : void GlobalHandles::AnnotateStrongRetainer(Address* location,
812 : const char* label) {
813 : Node::FromLocation(location)->AnnotateStrongRetainer(label);
814 2827990 : }
815 :
816 20 : bool GlobalHandles::IsWeak(Address* location) {
817 20 : return Node::FromLocation(location)->IsWeak();
818 : }
819 :
820 : DISABLE_CFI_PERF
821 68865 : void GlobalHandles::IterateWeakRootsForFinalizers(RootVisitor* v) {
822 24059240 : for (Node* node : *regular_nodes_) {
823 23990376 : if (node->IsWeakRetainer() && node->state() == Node::PENDING) {
824 : DCHECK(!node->IsPhantomCallback());
825 : DCHECK(!node->IsPhantomResetHandle());
826 : // Finalizers need to survive.
827 : v->VisitRootPointer(Root::kGlobalHandles, node->label(),
828 42208 : node->location());
829 : }
830 : }
831 68864 : }
832 :
833 : DISABLE_CFI_PERF
834 68800 : void GlobalHandles::IterateWeakRootsForPhantomHandles(
835 : WeakSlotCallbackWithHeap should_reset_handle) {
836 24059136 : for (Node* node : *regular_nodes_) {
837 29346272 : if (node->IsWeakRetainer() &&
838 5356000 : should_reset_handle(isolate()->heap(), node->location())) {
839 3048810 : if (node->IsPhantomResetHandle()) {
840 : node->MarkPending();
841 : node->ResetPhantomHandle();
842 31 : ++number_of_phantom_handle_resets_;
843 3048779 : } else if (node->IsPhantomCallback()) {
844 : node->MarkPending();
845 3048779 : node->CollectPhantomCallbackData(®ular_pending_phantom_callbacks_);
846 : }
847 : }
848 : }
849 76544 : for (TracedNode* node : *traced_nodes_) {
850 7710 : if (node->IsInUse() &&
851 30 : should_reset_handle(isolate()->heap(), node->location())) {
852 20 : if (node->IsPhantomResetHandle()) {
853 : node->ResetPhantomHandle();
854 15 : ++number_of_phantom_handle_resets_;
855 : } else {
856 5 : node->CollectPhantomCallbackData(&traced_pending_phantom_callbacks_);
857 : }
858 : }
859 : }
860 68864 : }
861 :
862 68864 : void GlobalHandles::IterateWeakRootsIdentifyFinalizers(
863 : WeakSlotCallbackWithHeap should_reset_handle) {
864 24059352 : for (Node* node : *regular_nodes_) {
865 29346488 : if (node->IsWeak() &&
866 5356000 : should_reset_handle(isolate()->heap(), node->location())) {
867 3069922 : if (node->IsFinalizerHandle()) {
868 : node->MarkPending();
869 : }
870 : }
871 : }
872 68864 : }
873 :
874 27814 : void GlobalHandles::IdentifyWeakUnmodifiedObjects(
875 : WeakSlotCallback is_unmodified) {
876 572186 : for (Node* node : young_nodes_) {
877 896739 : if (node->IsWeak() && !is_unmodified(node->location())) {
878 : node->set_active(true);
879 : }
880 : }
881 :
882 : LocalEmbedderHeapTracer* const tracer =
883 : isolate()->heap()->local_embedder_heap_tracer();
884 27839 : for (TracedNode* node : traced_young_nodes_) {
885 25 : if (node->IsInUse()) {
886 : DCHECK(node->is_root());
887 25 : if (is_unmodified(node->location())) {
888 15 : v8::Value* value = ToApi<v8::Value>(node->handle());
889 : node->set_root(tracer->IsRootForNonTracingGC(
890 : *reinterpret_cast<v8::TracedGlobal<v8::Value>*>(&value)));
891 : }
892 : }
893 : }
894 27814 : }
895 :
896 27814 : void GlobalHandles::IterateYoungStrongAndDependentRoots(RootVisitor* v) {
897 572186 : for (Node* node : young_nodes_) {
898 1453737 : if (node->IsStrongRetainer() ||
899 670394 : (node->IsWeakRetainer() && !node->is_independent() &&
900 : node->is_active())) {
901 : v->VisitRootPointer(Root::kGlobalHandles, node->label(),
902 994740 : node->location());
903 : }
904 : }
905 27839 : for (TracedNode* node : traced_young_nodes_) {
906 50 : if (node->IsInUse() && node->is_root()) {
907 30 : v->VisitRootPointer(Root::kGlobalHandles, nullptr, node->location());
908 : }
909 : }
910 27814 : }
911 :
912 27814 : void GlobalHandles::MarkYoungWeakUnmodifiedObjectsPending(
913 : WeakSlotCallbackWithHeap is_dead) {
914 572186 : for (Node* node : young_nodes_) {
915 : DCHECK(node->is_in_young_list());
916 1315161 : if ((node->is_independent() || !node->is_active()) && node->IsWeak() &&
917 68752 : is_dead(isolate_->heap(), node->location())) {
918 7732 : if (!node->IsPhantomCallback() && !node->IsPhantomResetHandle()) {
919 : node->MarkPending();
920 : }
921 : }
922 : }
923 27814 : }
924 :
925 27814 : void GlobalHandles::IterateYoungWeakUnmodifiedRootsForFinalizers(
926 : RootVisitor* v) {
927 572186 : for (Node* node : young_nodes_) {
928 : DCHECK(node->is_in_young_list());
929 1280785 : if ((node->is_independent() || !node->is_active()) &&
930 578748 : node->IsWeakRetainer() && (node->state() == Node::PENDING)) {
931 : DCHECK(!node->IsPhantomCallback());
932 : DCHECK(!node->IsPhantomResetHandle());
933 : // Finalizers need to survive.
934 : v->VisitRootPointer(Root::kGlobalHandles, node->label(),
935 0 : node->location());
936 : }
937 : }
938 27814 : }
939 :
940 27814 : void GlobalHandles::IterateYoungWeakUnmodifiedRootsForPhantomHandles(
941 : RootVisitor* v, WeakSlotCallbackWithHeap should_reset_handle) {
942 572186 : for (Node* node : young_nodes_) {
943 : DCHECK(node->is_in_young_list());
944 1280785 : if ((node->is_independent() || !node->is_active()) &&
945 578748 : node->IsWeakRetainer() && (node->state() != Node::PENDING)) {
946 68752 : if (should_reset_handle(isolate_->heap(), node->location())) {
947 : DCHECK(node->IsPhantomResetHandle() || node->IsPhantomCallback());
948 7732 : if (node->IsPhantomResetHandle()) {
949 : node->MarkPending();
950 : node->ResetPhantomHandle();
951 0 : ++number_of_phantom_handle_resets_;
952 7732 : } else if (node->IsPhantomCallback()) {
953 : node->MarkPending();
954 7732 : node->CollectPhantomCallbackData(®ular_pending_phantom_callbacks_);
955 : } else {
956 0 : UNREACHABLE();
957 : }
958 : } else {
959 : // Node survived and needs to be visited.
960 : v->VisitRootPointer(Root::kGlobalHandles, node->label(),
961 53288 : node->location());
962 : }
963 : }
964 : }
965 27839 : for (TracedNode* node : traced_young_nodes_) {
966 25 : if (!node->IsInUse()) continue;
967 :
968 : DCHECK_IMPLIES(node->is_root(),
969 : !should_reset_handle(isolate_->heap(), node->location()));
970 50 : if (should_reset_handle(isolate_->heap(), node->location())) {
971 10 : if (node->IsPhantomResetHandle()) {
972 : node->ResetPhantomHandle();
973 5 : ++number_of_phantom_handle_resets_;
974 : } else {
975 5 : node->CollectPhantomCallbackData(&traced_pending_phantom_callbacks_);
976 : }
977 : } else {
978 15 : if (!node->is_root()) {
979 : node->set_root(true);
980 0 : v->VisitRootPointer(Root::kGlobalHandles, nullptr, node->location());
981 : }
982 : }
983 : }
984 27814 : }
985 :
986 634 : void GlobalHandles::InvokeSecondPassPhantomCallbacksFromTask() {
987 : DCHECK(second_pass_callbacks_task_posted_);
988 634 : second_pass_callbacks_task_posted_ = false;
989 1902 : TRACE_EVENT0("v8", "V8.GCPhantomHandleProcessingCallback");
990 : isolate()->heap()->CallGCPrologueCallbacks(
991 634 : GCType::kGCTypeProcessWeakCallbacks, kNoGCCallbackFlags);
992 634 : InvokeSecondPassPhantomCallbacks();
993 : isolate()->heap()->CallGCEpilogueCallbacks(
994 634 : GCType::kGCTypeProcessWeakCallbacks, kNoGCCallbackFlags);
995 634 : }
996 :
997 102004 : void GlobalHandles::InvokeSecondPassPhantomCallbacks() {
998 5499324 : while (!second_pass_callbacks_.empty()) {
999 2698660 : auto callback = second_pass_callbacks_.back();
1000 : second_pass_callbacks_.pop_back();
1001 : callback.Invoke(isolate(), PendingPhantomCallback::kSecondPass);
1002 : }
1003 102004 : }
1004 :
1005 27814 : size_t GlobalHandles::PostScavengeProcessing(unsigned post_processing_count) {
1006 : size_t freed_nodes = 0;
1007 572186 : for (Node* node : young_nodes_) {
1008 : // Filter free nodes.
1009 544372 : if (!node->IsRetainer()) continue;
1010 :
1011 : // Reset active state for all affected nodes.
1012 : node->set_active(false);
1013 :
1014 524014 : if (node->IsPending()) {
1015 : DCHECK(node->has_callback());
1016 : DCHECK(node->IsPendingFinalizer());
1017 0 : node->PostGarbageCollectionProcessing(isolate_);
1018 : }
1019 524014 : if (InRecursiveGC(post_processing_count)) return freed_nodes;
1020 :
1021 524014 : if (!node->IsRetainer()) freed_nodes++;
1022 : }
1023 : return freed_nodes;
1024 : }
1025 :
1026 68864 : size_t GlobalHandles::PostMarkSweepProcessing(unsigned post_processing_count) {
1027 : size_t freed_nodes = 0;
1028 21722112 : for (Node* node : *regular_nodes_) {
1029 : // Filter free nodes.
1030 21653248 : if (!node->IsRetainer()) continue;
1031 :
1032 : // Reset active state for all affected nodes.
1033 : node->set_active(false);
1034 :
1035 4525049 : if (node->IsPending()) {
1036 : DCHECK(node->has_callback());
1037 : DCHECK(node->IsPendingFinalizer());
1038 21104 : node->PostGarbageCollectionProcessing(isolate_);
1039 : }
1040 4525049 : if (InRecursiveGC(post_processing_count)) return freed_nodes;
1041 :
1042 4525049 : if (!node->IsRetainer()) freed_nodes++;
1043 : }
1044 68864 : return freed_nodes;
1045 : }
1046 :
1047 : template <typename T>
1048 193356 : void GlobalHandles::UpdateAndCompactListOfYoungNode(
1049 : std::vector<T*>* node_list) {
1050 : size_t last = 0;
1051 4897703 : for (T* node : *node_list) {
1052 : DCHECK(node->is_in_young_list());
1053 4704347 : if (node->IsInUse()) {
1054 2093981 : if (ObjectInYoungGeneration(node->object())) {
1055 3395942 : (*node_list)[last++] = node;
1056 1697971 : isolate_->heap()->IncrementNodesCopiedInNewSpace();
1057 : } else {
1058 : node->set_in_young_list(false);
1059 396010 : isolate_->heap()->IncrementNodesPromoted();
1060 : }
1061 : } else {
1062 : node->set_in_young_list(false);
1063 2610366 : isolate_->heap()->IncrementNodesDiedInNewSpace();
1064 : }
1065 : }
1066 : DCHECK_LE(last, node_list->size());
1067 193356 : node_list->resize(last);
1068 : node_list->shrink_to_fit();
1069 193356 : }
1070 :
1071 0 : void GlobalHandles::UpdateListOfYoungNodes() {
1072 96678 : UpdateAndCompactListOfYoungNode(&young_nodes_);
1073 96678 : UpdateAndCompactListOfYoungNode(&traced_young_nodes_);
1074 0 : }
1075 :
1076 : template <typename T>
1077 193356 : size_t GlobalHandles::InvokeFirstPassWeakCallbacks(
1078 : std::vector<std::pair<T*, PendingPhantomCallback>>* pending) {
1079 : size_t freed_nodes = 0;
1080 : std::vector<std::pair<T*, PendingPhantomCallback>> pending_phantom_callbacks;
1081 : pending_phantom_callbacks.swap(*pending);
1082 : {
1083 : // The initial pass callbacks must simply clear the nodes.
1084 3249877 : for (auto& pair : pending_phantom_callbacks) {
1085 3056521 : T* node = pair.first;
1086 : DCHECK_EQ(T::NEAR_DEATH, node->state());
1087 : pair.second.Invoke(isolate(), PendingPhantomCallback::kFirstPass);
1088 :
1089 : // Transition to second pass. It is required that the first pass callback
1090 : // resets the handle using |v8::PersistentBase::Reset|. Also see comments
1091 : // on |v8::WeakCallbackInfo|.
1092 3056521 : CHECK_WITH_MSG(T::FREE == node->state(),
1093 : "Handle not reset in first callback. See comments on "
1094 : "|v8::WeakCallbackInfo|.");
1095 :
1096 3056521 : if (pair.second.callback()) second_pass_callbacks_.push_back(pair.second);
1097 3056521 : freed_nodes++;
1098 : }
1099 : }
1100 193356 : return freed_nodes;
1101 : }
1102 :
1103 96678 : size_t GlobalHandles::InvokeFirstPassWeakCallbacks() {
1104 96678 : return InvokeFirstPassWeakCallbacks(®ular_pending_phantom_callbacks_) +
1105 96678 : InvokeFirstPassWeakCallbacks(&traced_pending_phantom_callbacks_);
1106 : }
1107 :
1108 96678 : void GlobalHandles::InvokeOrScheduleSecondPassPhantomCallbacks(
1109 : bool synchronous_second_pass) {
1110 96678 : if (!second_pass_callbacks_.empty()) {
1111 5913 : if (FLAG_optimize_for_size || FLAG_predictable || synchronous_second_pass) {
1112 : isolate()->heap()->CallGCPrologueCallbacks(
1113 4692 : GCType::kGCTypeProcessWeakCallbacks, kNoGCCallbackFlags);
1114 4692 : InvokeSecondPassPhantomCallbacks();
1115 : isolate()->heap()->CallGCEpilogueCallbacks(
1116 4692 : GCType::kGCTypeProcessWeakCallbacks, kNoGCCallbackFlags);
1117 1221 : } else if (!second_pass_callbacks_task_posted_) {
1118 634 : second_pass_callbacks_task_posted_ = true;
1119 634 : auto taskrunner = V8::GetCurrentPlatform()->GetForegroundTaskRunner(
1120 634 : reinterpret_cast<v8::Isolate*>(isolate()));
1121 2536 : taskrunner->PostTask(MakeCancelableTask(
1122 1902 : isolate(), [this] { InvokeSecondPassPhantomCallbacksFromTask(); }));
1123 : }
1124 : }
1125 96678 : }
1126 :
1127 0 : void GlobalHandles::PendingPhantomCallback::Invoke(Isolate* isolate,
1128 : InvocationType type) {
1129 : Data::Callback* callback_addr = nullptr;
1130 0 : if (type == kFirstPass) {
1131 3056521 : callback_addr = &callback_;
1132 : }
1133 : Data data(reinterpret_cast<v8::Isolate*>(isolate), parameter_,
1134 5755181 : embedder_fields_, callback_addr);
1135 5755181 : Data::Callback callback = callback_;
1136 5755181 : callback_ = nullptr;
1137 5755181 : callback(data);
1138 0 : }
1139 :
1140 0 : bool GlobalHandles::InRecursiveGC(unsigned gc_processing_counter) {
1141 5242419 : return gc_processing_counter != post_gc_processing_count_;
1142 : }
1143 :
1144 96678 : size_t GlobalHandles::PostGarbageCollectionProcessing(
1145 : GarbageCollector collector, const v8::GCCallbackFlags gc_callback_flags) {
1146 : // Process weak global handle callbacks. This must be done after the
1147 : // GC is completely done, because the callbacks may invoke arbitrary
1148 : // API functions.
1149 : DCHECK_EQ(Heap::NOT_IN_GC, isolate_->heap()->gc_state());
1150 96678 : const unsigned post_processing_count = ++post_gc_processing_count_;
1151 : size_t freed_nodes = 0;
1152 : bool synchronous_second_pass =
1153 193356 : isolate_->heap()->IsTearingDown() ||
1154 96678 : (gc_callback_flags &
1155 : (kGCCallbackFlagForced | kGCCallbackFlagCollectAllAvailableGarbage |
1156 : kGCCallbackFlagSynchronousPhantomCallbackProcessing)) != 0;
1157 96678 : InvokeOrScheduleSecondPassPhantomCallbacks(synchronous_second_pass);
1158 96678 : if (InRecursiveGC(post_processing_count)) return freed_nodes;
1159 :
1160 : freed_nodes += Heap::IsYoungGenerationCollector(collector)
1161 : ? PostScavengeProcessing(post_processing_count)
1162 96678 : : PostMarkSweepProcessing(post_processing_count);
1163 96678 : if (InRecursiveGC(post_processing_count)) return freed_nodes;
1164 :
1165 : UpdateListOfYoungNodes();
1166 96678 : return freed_nodes;
1167 : }
1168 :
1169 117320 : void GlobalHandles::IterateStrongRoots(RootVisitor* v) {
1170 38283336 : for (Node* node : *regular_nodes_) {
1171 38166016 : if (node->IsStrongRetainer()) {
1172 : v->VisitRootPointer(Root::kGlobalHandles, node->label(),
1173 9776790 : node->location());
1174 : }
1175 : }
1176 117320 : }
1177 :
1178 398 : void GlobalHandles::IterateWeakRoots(RootVisitor* v) {
1179 102286 : for (Node* node : *regular_nodes_) {
1180 101888 : if (node->IsWeak()) {
1181 : v->VisitRootPointer(Root::kGlobalHandles, node->label(),
1182 110 : node->location());
1183 : }
1184 : }
1185 398 : for (TracedNode* node : *traced_nodes_) {
1186 0 : if (node->IsInUse()) {
1187 0 : v->VisitRootPointer(Root::kGlobalHandles, nullptr, node->location());
1188 : }
1189 : }
1190 398 : }
1191 :
1192 : DISABLE_CFI_PERF
1193 70748 : void GlobalHandles::IterateAllRoots(RootVisitor* v) {
1194 24498268 : for (Node* node : *regular_nodes_) {
1195 24427520 : if (node->IsRetainer()) {
1196 : v->VisitRootPointer(Root::kGlobalHandles, node->label(),
1197 9674168 : node->location());
1198 : }
1199 : }
1200 74588 : for (TracedNode* node : *traced_nodes_) {
1201 3840 : if (node->IsRetainer()) {
1202 20 : v->VisitRootPointer(Root::kGlobalHandles, nullptr, node->location());
1203 : }
1204 : }
1205 70748 : }
1206 :
1207 : DISABLE_CFI_PERF
1208 0 : void GlobalHandles::IterateAllYoungRoots(RootVisitor* v) {
1209 0 : for (Node* node : young_nodes_) {
1210 0 : if (node->IsRetainer()) {
1211 : v->VisitRootPointer(Root::kGlobalHandles, node->label(),
1212 0 : node->location());
1213 : }
1214 : }
1215 0 : for (TracedNode* node : traced_young_nodes_) {
1216 0 : if (node->IsRetainer()) {
1217 0 : v->VisitRootPointer(Root::kGlobalHandles, nullptr, node->location());
1218 : }
1219 : }
1220 0 : }
1221 :
1222 : DISABLE_CFI_PERF
1223 0 : void GlobalHandles::ApplyPersistentHandleVisitor(
1224 : v8::PersistentHandleVisitor* visitor, GlobalHandles::Node* node) {
1225 20 : v8::Value* value = ToApi<v8::Value>(node->handle());
1226 20 : visitor->VisitPersistentHandle(
1227 : reinterpret_cast<v8::Persistent<v8::Value>*>(&value),
1228 40 : node->wrapper_class_id());
1229 0 : }
1230 :
1231 : DISABLE_CFI_PERF
1232 10 : void GlobalHandles::IterateAllRootsWithClassIds(
1233 : v8::PersistentHandleVisitor* visitor) {
1234 2570 : for (Node* node : *regular_nodes_) {
1235 2560 : if (node->IsRetainer() && node->has_wrapper_class_id()) {
1236 : ApplyPersistentHandleVisitor(visitor, node);
1237 : }
1238 : }
1239 10 : }
1240 :
1241 : DISABLE_CFI_PERF
1242 5 : void GlobalHandles::IterateTracedNodes(
1243 : v8::EmbedderHeapTracer::TracedGlobalHandleVisitor* visitor) {
1244 1285 : for (TracedNode* node : *traced_nodes_) {
1245 1280 : if (node->IsInUse()) {
1246 5 : v8::Value* value = ToApi<v8::Value>(node->handle());
1247 : visitor->VisitTracedGlobalHandle(
1248 5 : *reinterpret_cast<v8::TracedGlobal<v8::Value>*>(&value));
1249 : }
1250 : }
1251 5 : }
1252 :
1253 : DISABLE_CFI_PERF
1254 0 : void GlobalHandles::IterateAllYoungRootsWithClassIds(
1255 : v8::PersistentHandleVisitor* visitor) {
1256 0 : for (Node* node : young_nodes_) {
1257 0 : if (node->IsRetainer() && node->has_wrapper_class_id()) {
1258 : ApplyPersistentHandleVisitor(visitor, node);
1259 : }
1260 : }
1261 0 : }
1262 :
1263 : DISABLE_CFI_PERF
1264 0 : void GlobalHandles::IterateYoungWeakRootsWithClassIds(
1265 : v8::PersistentHandleVisitor* visitor) {
1266 0 : for (Node* node : young_nodes_) {
1267 0 : if (node->has_wrapper_class_id() && node->IsWeak()) {
1268 : ApplyPersistentHandleVisitor(visitor, node);
1269 : }
1270 : }
1271 0 : }
1272 :
1273 15 : void GlobalHandles::RecordStats(HeapStats* stats) {
1274 15 : *stats->global_handle_count = 0;
1275 15 : *stats->weak_global_handle_count = 0;
1276 15 : *stats->pending_global_handle_count = 0;
1277 15 : *stats->near_death_global_handle_count = 0;
1278 15 : *stats->free_global_handle_count = 0;
1279 15 : for (Node* node : *regular_nodes_) {
1280 0 : *stats->global_handle_count += 1;
1281 0 : if (node->state() == Node::WEAK) {
1282 0 : *stats->weak_global_handle_count += 1;
1283 0 : } else if (node->state() == Node::PENDING) {
1284 0 : *stats->pending_global_handle_count += 1;
1285 0 : } else if (node->state() == Node::NEAR_DEATH) {
1286 0 : *stats->near_death_global_handle_count += 1;
1287 0 : } else if (node->state() == Node::FREE) {
1288 0 : *stats->free_global_handle_count += 1;
1289 : }
1290 : }
1291 15 : }
1292 :
1293 : #ifdef DEBUG
1294 :
1295 : void GlobalHandles::PrintStats() {
1296 : int total = 0;
1297 : int weak = 0;
1298 : int pending = 0;
1299 : int near_death = 0;
1300 : int destroyed = 0;
1301 :
1302 : for (Node* node : *regular_nodes_) {
1303 : total++;
1304 : if (node->state() == Node::WEAK) weak++;
1305 : if (node->state() == Node::PENDING) pending++;
1306 : if (node->state() == Node::NEAR_DEATH) near_death++;
1307 : if (node->state() == Node::FREE) destroyed++;
1308 : }
1309 :
1310 : PrintF("Global Handle Statistics:\n");
1311 : PrintF(" allocated memory = %" PRIuS "B\n", total * sizeof(Node));
1312 : PrintF(" # weak = %d\n", weak);
1313 : PrintF(" # pending = %d\n", pending);
1314 : PrintF(" # near_death = %d\n", near_death);
1315 : PrintF(" # free = %d\n", destroyed);
1316 : PrintF(" # total = %d\n", total);
1317 : }
1318 :
1319 :
1320 : void GlobalHandles::Print() {
1321 : PrintF("Global handles:\n");
1322 : for (Node* node : *regular_nodes_) {
1323 : PrintF(" handle %p to %p%s\n", node->location().ToVoidPtr(),
1324 : reinterpret_cast<void*>(node->object()->ptr()),
1325 : node->IsWeak() ? " (weak)" : "");
1326 : }
1327 : }
1328 :
1329 : #endif
1330 :
1331 124810 : EternalHandles::~EternalHandles() {
1332 62490 : for (Address* block : blocks_) delete[] block;
1333 62405 : }
1334 :
1335 187670 : void EternalHandles::IterateAllRoots(RootVisitor* visitor) {
1336 187670 : int limit = size_;
1337 188079 : for (Address* block : blocks_) {
1338 : DCHECK_GT(limit, 0);
1339 818 : visitor->VisitRootPointers(Root::kEternalHandles, nullptr,
1340 : FullObjectSlot(block),
1341 818 : FullObjectSlot(block + Min(limit, kSize)));
1342 409 : limit -= kSize;
1343 : }
1344 187670 : }
1345 :
1346 27814 : void EternalHandles::IterateYoungRoots(RootVisitor* visitor) {
1347 42678 : for (int index : young_node_indices_) {
1348 14864 : visitor->VisitRootPointer(Root::kEternalHandles, nullptr,
1349 29728 : FullObjectSlot(GetLocation(index)));
1350 : }
1351 27814 : }
1352 :
1353 96678 : void EternalHandles::PostGarbageCollectionProcessing() {
1354 : size_t last = 0;
1355 137569 : for (int index : young_node_indices_) {
1356 81782 : if (ObjectInYoungGeneration(Object(*GetLocation(index)))) {
1357 40842 : young_node_indices_[last++] = index;
1358 : }
1359 : }
1360 : DCHECK_LE(last, young_node_indices_.size());
1361 96678 : young_node_indices_.resize(last);
1362 96678 : }
1363 :
1364 20480 : void EternalHandles::Create(Isolate* isolate, Object object, int* index) {
1365 : DCHECK_EQ(kInvalidIndex, *index);
1366 20480 : if (object == Object()) return;
1367 : Object the_hole = ReadOnlyRoots(isolate).the_hole_value();
1368 : DCHECK_NE(the_hole, object);
1369 20480 : int block = size_ >> kShift;
1370 20480 : int offset = size_ & kMask;
1371 : // Need to resize.
1372 20480 : if (offset == 0) {
1373 85 : Address* next_block = new Address[kSize];
1374 : MemsetPointer(FullObjectSlot(next_block), the_hole, kSize);
1375 85 : blocks_.push_back(next_block);
1376 : }
1377 : DCHECK_EQ(the_hole->ptr(), blocks_[block][offset]);
1378 40960 : blocks_[block][offset] = object->ptr();
1379 20480 : if (ObjectInYoungGeneration(object)) {
1380 20475 : young_node_indices_.push_back(size_);
1381 : }
1382 20480 : *index = size_++;
1383 : }
1384 :
1385 : } // namespace internal
1386 121996 : } // namespace v8
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