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Diffstat (limited to 'deps/v8/src/heap/objects-visiting.cc')
| -rw-r--r-- | deps/v8/src/heap/objects-visiting.cc | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/deps/v8/src/heap/objects-visiting.cc b/deps/v8/src/heap/objects-visiting.cc new file mode 100644 index 000000000..a316d12dc --- /dev/null +++ b/deps/v8/src/heap/objects-visiting.cc @@ -0,0 +1,414 @@ +// Copyright 2011 the V8 project authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "src/v8.h" + +#include "src/heap/objects-visiting.h" +#include "src/ic-inl.h" + +namespace v8 { +namespace internal { + + +StaticVisitorBase::VisitorId StaticVisitorBase::GetVisitorId( + int instance_type, int instance_size) { + if (instance_type < FIRST_NONSTRING_TYPE) { + switch (instance_type & kStringRepresentationMask) { + case kSeqStringTag: + if ((instance_type & kStringEncodingMask) == kOneByteStringTag) { + return kVisitSeqOneByteString; + } else { + return kVisitSeqTwoByteString; + } + + case kConsStringTag: + if (IsShortcutCandidate(instance_type)) { + return kVisitShortcutCandidate; + } else { + return kVisitConsString; + } + + case kSlicedStringTag: + return kVisitSlicedString; + + case kExternalStringTag: + return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric, + instance_size); + } + UNREACHABLE(); + } + + switch (instance_type) { + case BYTE_ARRAY_TYPE: + return kVisitByteArray; + + case FREE_SPACE_TYPE: + return kVisitFreeSpace; + + case FIXED_ARRAY_TYPE: + return kVisitFixedArray; + + case FIXED_DOUBLE_ARRAY_TYPE: + return kVisitFixedDoubleArray; + + case CONSTANT_POOL_ARRAY_TYPE: + return kVisitConstantPoolArray; + + case ODDBALL_TYPE: + return kVisitOddball; + + case MAP_TYPE: + return kVisitMap; + + case CODE_TYPE: + return kVisitCode; + + case CELL_TYPE: + return kVisitCell; + + case PROPERTY_CELL_TYPE: + return kVisitPropertyCell; + + case JS_SET_TYPE: + return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, + JSSet::kSize); + + case JS_MAP_TYPE: + return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, + JSMap::kSize); + + case JS_WEAK_MAP_TYPE: + case JS_WEAK_SET_TYPE: + return kVisitJSWeakCollection; + + case JS_REGEXP_TYPE: + return kVisitJSRegExp; + + case SHARED_FUNCTION_INFO_TYPE: + return kVisitSharedFunctionInfo; + + case JS_PROXY_TYPE: + return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, + JSProxy::kSize); + + case JS_FUNCTION_PROXY_TYPE: + return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, + JSFunctionProxy::kSize); + + case FOREIGN_TYPE: + return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric, + Foreign::kSize); + + case SYMBOL_TYPE: + return kVisitSymbol; + + case FILLER_TYPE: + return kVisitDataObjectGeneric; + + case JS_ARRAY_BUFFER_TYPE: + return kVisitJSArrayBuffer; + + case JS_TYPED_ARRAY_TYPE: + return kVisitJSTypedArray; + + case JS_DATA_VIEW_TYPE: + return kVisitJSDataView; + + case JS_OBJECT_TYPE: + case JS_CONTEXT_EXTENSION_OBJECT_TYPE: + case JS_GENERATOR_OBJECT_TYPE: + case JS_MODULE_TYPE: + case JS_VALUE_TYPE: + case JS_DATE_TYPE: + case JS_ARRAY_TYPE: + case JS_GLOBAL_PROXY_TYPE: + case JS_GLOBAL_OBJECT_TYPE: + case JS_BUILTINS_OBJECT_TYPE: + case JS_MESSAGE_OBJECT_TYPE: + case JS_SET_ITERATOR_TYPE: + case JS_MAP_ITERATOR_TYPE: + return GetVisitorIdForSize(kVisitJSObject, kVisitJSObjectGeneric, + instance_size); + + case JS_FUNCTION_TYPE: + return kVisitJSFunction; + + case HEAP_NUMBER_TYPE: + case MUTABLE_HEAP_NUMBER_TYPE: +#define EXTERNAL_ARRAY_CASE(Type, type, TYPE, ctype, size) \ + case EXTERNAL_##TYPE##_ARRAY_TYPE: + + TYPED_ARRAYS(EXTERNAL_ARRAY_CASE) + return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric, + instance_size); +#undef EXTERNAL_ARRAY_CASE + + case FIXED_UINT8_ARRAY_TYPE: + case FIXED_INT8_ARRAY_TYPE: + case FIXED_UINT16_ARRAY_TYPE: + case FIXED_INT16_ARRAY_TYPE: + case FIXED_UINT32_ARRAY_TYPE: + case FIXED_INT32_ARRAY_TYPE: + case FIXED_FLOAT32_ARRAY_TYPE: + case FIXED_UINT8_CLAMPED_ARRAY_TYPE: + return kVisitFixedTypedArray; + + case FIXED_FLOAT64_ARRAY_TYPE: + return kVisitFixedFloat64Array; + +#define MAKE_STRUCT_CASE(NAME, Name, name) case NAME##_TYPE: + STRUCT_LIST(MAKE_STRUCT_CASE) +#undef MAKE_STRUCT_CASE + if (instance_type == ALLOCATION_SITE_TYPE) { + return kVisitAllocationSite; + } + + return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, + instance_size); + + default: + UNREACHABLE(); + return kVisitorIdCount; + } +} + + +// We don't record weak slots during marking or scavenges. Instead we do it +// once when we complete mark-compact cycle. Note that write barrier has no +// effect if we are already in the middle of compacting mark-sweep cycle and we +// have to record slots manually. +static bool MustRecordSlots(Heap* heap) { + return heap->gc_state() == Heap::MARK_COMPACT && + heap->mark_compact_collector()->is_compacting(); +} + + +template <class T> +struct WeakListVisitor; + + +template <class T> +Object* VisitWeakList(Heap* heap, Object* list, WeakObjectRetainer* retainer) { + Object* undefined = heap->undefined_value(); + Object* head = undefined; + T* tail = NULL; + MarkCompactCollector* collector = heap->mark_compact_collector(); + bool record_slots = MustRecordSlots(heap); + while (list != undefined) { + // Check whether to keep the candidate in the list. + T* candidate = reinterpret_cast<T*>(list); + Object* retained = retainer->RetainAs(list); + if (retained != NULL) { + if (head == undefined) { + // First element in the list. + head = retained; + } else { + // Subsequent elements in the list. + DCHECK(tail != NULL); + WeakListVisitor<T>::SetWeakNext(tail, retained); + if (record_slots) { + Object** next_slot = + HeapObject::RawField(tail, WeakListVisitor<T>::WeakNextOffset()); + collector->RecordSlot(next_slot, next_slot, retained); + } + } + // Retained object is new tail. + DCHECK(!retained->IsUndefined()); + candidate = reinterpret_cast<T*>(retained); + tail = candidate; + + + // tail is a live object, visit it. + WeakListVisitor<T>::VisitLiveObject(heap, tail, retainer); + } else { + WeakListVisitor<T>::VisitPhantomObject(heap, candidate); + } + + // Move to next element in the list. + list = WeakListVisitor<T>::WeakNext(candidate); + } + + // Terminate the list if there is one or more elements. + if (tail != NULL) { + WeakListVisitor<T>::SetWeakNext(tail, undefined); + } + return head; +} + + +template <class T> +static void ClearWeakList(Heap* heap, Object* list) { + Object* undefined = heap->undefined_value(); + while (list != undefined) { + T* candidate = reinterpret_cast<T*>(list); + list = WeakListVisitor<T>::WeakNext(candidate); + WeakListVisitor<T>::SetWeakNext(candidate, undefined); + } +} + + +template <> +struct WeakListVisitor<JSFunction> { + static void SetWeakNext(JSFunction* function, Object* next) { + function->set_next_function_link(next); + } + + static Object* WeakNext(JSFunction* function) { + return function->next_function_link(); + } + + static int WeakNextOffset() { return JSFunction::kNextFunctionLinkOffset; } + + static void VisitLiveObject(Heap*, JSFunction*, WeakObjectRetainer*) {} + + static void VisitPhantomObject(Heap*, JSFunction*) {} +}; + + +template <> +struct WeakListVisitor<Code> { + static void SetWeakNext(Code* code, Object* next) { + code->set_next_code_link(next); + } + + static Object* WeakNext(Code* code) { return code->next_code_link(); } + + static int WeakNextOffset() { return Code::kNextCodeLinkOffset; } + + static void VisitLiveObject(Heap*, Code*, WeakObjectRetainer*) {} + + static void VisitPhantomObject(Heap*, Code*) {} +}; + + +template <> +struct WeakListVisitor<Context> { + static void SetWeakNext(Context* context, Object* next) { + context->set(Context::NEXT_CONTEXT_LINK, next, UPDATE_WRITE_BARRIER); + } + + static Object* WeakNext(Context* context) { + return context->get(Context::NEXT_CONTEXT_LINK); + } + + static int WeakNextOffset() { + return FixedArray::SizeFor(Context::NEXT_CONTEXT_LINK); + } + + static void VisitLiveObject(Heap* heap, Context* context, + WeakObjectRetainer* retainer) { + // Process the three weak lists linked off the context. + DoWeakList<JSFunction>(heap, context, retainer, + Context::OPTIMIZED_FUNCTIONS_LIST); + DoWeakList<Code>(heap, context, retainer, Context::OPTIMIZED_CODE_LIST); + DoWeakList<Code>(heap, context, retainer, Context::DEOPTIMIZED_CODE_LIST); + } + + template <class T> + static void DoWeakList(Heap* heap, Context* context, + WeakObjectRetainer* retainer, int index) { + // Visit the weak list, removing dead intermediate elements. + Object* list_head = VisitWeakList<T>(heap, context->get(index), retainer); + + // Update the list head. + context->set(index, list_head, UPDATE_WRITE_BARRIER); + + if (MustRecordSlots(heap)) { + // Record the updated slot if necessary. + Object** head_slot = + HeapObject::RawField(context, FixedArray::SizeFor(index)); + heap->mark_compact_collector()->RecordSlot(head_slot, head_slot, + list_head); + } + } + + static void VisitPhantomObject(Heap* heap, Context* context) { + ClearWeakList<JSFunction>(heap, + context->get(Context::OPTIMIZED_FUNCTIONS_LIST)); + ClearWeakList<Code>(heap, context->get(Context::OPTIMIZED_CODE_LIST)); + ClearWeakList<Code>(heap, context->get(Context::DEOPTIMIZED_CODE_LIST)); + } +}; + + +template <> +struct WeakListVisitor<JSArrayBufferView> { + static void SetWeakNext(JSArrayBufferView* obj, Object* next) { + obj->set_weak_next(next); + } + + static Object* WeakNext(JSArrayBufferView* obj) { return obj->weak_next(); } + + static int WeakNextOffset() { return JSArrayBufferView::kWeakNextOffset; } + + static void VisitLiveObject(Heap*, JSArrayBufferView*, WeakObjectRetainer*) {} + + static void VisitPhantomObject(Heap*, JSArrayBufferView*) {} +}; + + +template <> +struct WeakListVisitor<JSArrayBuffer> { + static void SetWeakNext(JSArrayBuffer* obj, Object* next) { + obj->set_weak_next(next); + } + + static Object* WeakNext(JSArrayBuffer* obj) { return obj->weak_next(); } + + static int WeakNextOffset() { return JSArrayBuffer::kWeakNextOffset; } + + static void VisitLiveObject(Heap* heap, JSArrayBuffer* array_buffer, + WeakObjectRetainer* retainer) { + Object* typed_array_obj = VisitWeakList<JSArrayBufferView>( + heap, array_buffer->weak_first_view(), retainer); + array_buffer->set_weak_first_view(typed_array_obj); + if (typed_array_obj != heap->undefined_value() && MustRecordSlots(heap)) { + Object** slot = HeapObject::RawField(array_buffer, + JSArrayBuffer::kWeakFirstViewOffset); + heap->mark_compact_collector()->RecordSlot(slot, slot, typed_array_obj); + } + } + + static void VisitPhantomObject(Heap* heap, JSArrayBuffer* phantom) { + Runtime::FreeArrayBuffer(heap->isolate(), phantom); + } +}; + + +template <> +struct WeakListVisitor<AllocationSite> { + static void SetWeakNext(AllocationSite* obj, Object* next) { + obj->set_weak_next(next); + } + + static Object* WeakNext(AllocationSite* obj) { return obj->weak_next(); } + + static int WeakNextOffset() { return AllocationSite::kWeakNextOffset; } + + static void VisitLiveObject(Heap*, AllocationSite*, WeakObjectRetainer*) {} + + static void VisitPhantomObject(Heap*, AllocationSite*) {} +}; + + +template Object* VisitWeakList<Code>(Heap* heap, Object* list, + WeakObjectRetainer* retainer); + + +template Object* VisitWeakList<JSFunction>(Heap* heap, Object* list, + WeakObjectRetainer* retainer); + + +template Object* VisitWeakList<Context>(Heap* heap, Object* list, + WeakObjectRetainer* retainer); + + +template Object* VisitWeakList<JSArrayBuffer>(Heap* heap, Object* list, + WeakObjectRetainer* retainer); + + +template Object* VisitWeakList<AllocationSite>(Heap* heap, Object* list, + WeakObjectRetainer* retainer); +} +} // namespace v8::internal |