| // Copyright 2011 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "v8.h" |
| |
| #include "ic-inl.h" |
| #include "objects-visiting.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| static inline bool IsShortcutCandidate(int type) { |
| return ((type & kShortcutTypeMask) == kShortcutTypeTag); |
| } |
| |
| |
| 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: |
| return kVisitJSWeakMap; |
| |
| case JS_WEAK_SET_TYPE: |
| return kVisitJSWeakSet; |
| |
| 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: |
| #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; |
| } |
| } |
| |
| |
| template <class T> |
| struct WeakListVisitor; |
| |
| |
| template <class T> |
| Object* VisitWeakList(Heap* heap, |
| Object* list, |
| WeakObjectRetainer* retainer, |
| bool record_slots) { |
| Object* undefined = heap->undefined_value(); |
| Object* head = undefined; |
| T* tail = NULL; |
| MarkCompactCollector* collector = heap->mark_compact_collector(); |
| 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. |
| ASSERT(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. |
| ASSERT(!retained->IsUndefined()); |
| candidate = reinterpret_cast<T*>(retained); |
| tail = candidate; |
| |
| |
| // tail is a live object, visit it. |
| WeakListVisitor<T>::VisitLiveObject( |
| heap, tail, retainer, record_slots); |
| } 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*, bool) { |
| } |
| |
| 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*, bool) { |
| } |
| |
| 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 void VisitLiveObject(Heap* heap, |
| Context* context, |
| WeakObjectRetainer* retainer, |
| bool record_slots) { |
| // Process the three weak lists linked off the context. |
| DoWeakList<JSFunction>(heap, context, retainer, record_slots, |
| Context::OPTIMIZED_FUNCTIONS_LIST); |
| DoWeakList<Code>(heap, context, retainer, record_slots, |
| Context::OPTIMIZED_CODE_LIST); |
| DoWeakList<Code>(heap, context, retainer, record_slots, |
| Context::DEOPTIMIZED_CODE_LIST); |
| } |
| |
| template<class T> |
| static void DoWeakList(Heap* heap, |
| Context* context, |
| WeakObjectRetainer* retainer, |
| bool record_slots, |
| int index) { |
| // Visit the weak list, removing dead intermediate elements. |
| Object* list_head = VisitWeakList<T>(heap, context->get(index), retainer, |
| record_slots); |
| |
| // Update the list head. |
| context->set(index, list_head, UPDATE_WRITE_BARRIER); |
| |
| if (record_slots) { |
| // 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)); |
| } |
| |
| static int WeakNextOffset() { |
| return FixedArray::SizeFor(Context::NEXT_CONTEXT_LINK); |
| } |
| }; |
| |
| |
| 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 void VisitLiveObject(Heap*, |
| JSArrayBufferView* obj, |
| WeakObjectRetainer* retainer, |
| bool record_slots) {} |
| |
| static void VisitPhantomObject(Heap*, JSArrayBufferView*) {} |
| |
| static int WeakNextOffset() { |
| return JSArrayBufferView::kWeakNextOffset; |
| } |
| }; |
| |
| |
| 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 void VisitLiveObject(Heap* heap, |
| JSArrayBuffer* array_buffer, |
| WeakObjectRetainer* retainer, |
| bool record_slots) { |
| Object* typed_array_obj = |
| VisitWeakList<JSArrayBufferView>( |
| heap, |
| array_buffer->weak_first_view(), |
| retainer, record_slots); |
| array_buffer->set_weak_first_view(typed_array_obj); |
| if (typed_array_obj != heap->undefined_value() && record_slots) { |
| 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); |
| } |
| |
| static int WeakNextOffset() { |
| return JSArrayBuffer::kWeakNextOffset; |
| } |
| }; |
| |
| |
| 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 void VisitLiveObject(Heap* heap, |
| AllocationSite* site, |
| WeakObjectRetainer* retainer, |
| bool record_slots) {} |
| |
| static void VisitPhantomObject(Heap* heap, AllocationSite* phantom) {} |
| |
| static int WeakNextOffset() { |
| return AllocationSite::kWeakNextOffset; |
| } |
| }; |
| |
| |
| template Object* VisitWeakList<Code>( |
| Heap* heap, Object* list, WeakObjectRetainer* retainer, bool record_slots); |
| |
| |
| template Object* VisitWeakList<JSFunction>( |
| Heap* heap, Object* list, WeakObjectRetainer* retainer, bool record_slots); |
| |
| |
| template Object* VisitWeakList<Context>( |
| Heap* heap, Object* list, WeakObjectRetainer* retainer, bool record_slots); |
| |
| |
| template Object* VisitWeakList<JSArrayBuffer>( |
| Heap* heap, Object* list, WeakObjectRetainer* retainer, bool record_slots); |
| |
| |
| template Object* VisitWeakList<AllocationSite>( |
| Heap* heap, Object* list, WeakObjectRetainer* retainer, bool record_slots); |
| |
| } } // namespace v8::internal |
