// Copyright 2012 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. #ifndef V8_HEAP_HEAP_INL_H_ #define V8_HEAP_HEAP_INL_H_ #include // Clients of this interface shouldn't depend on lots of heap internals. // Do not include anything from src/heap other than src/heap/heap.h and its // write barrier here! #include "src/heap/heap-write-barrier.h" #include "src/heap/heap.h" #include "src/base/platform/platform.h" #include "src/counters-inl.h" #include "src/feedback-vector.h" // TODO(mstarzinger): There is one more include to remove in order to no longer // leak heap internals to users of this interface! #include "src/heap/spaces-inl.h" #include "src/isolate.h" #include "src/log.h" #include "src/msan.h" #include "src/objects-inl.h" #include "src/objects/api-callbacks-inl.h" #include "src/objects/descriptor-array.h" #include "src/objects/literal-objects.h" #include "src/objects/scope-info.h" #include "src/objects/script-inl.h" #include "src/profiler/heap-profiler.h" #include "src/string-hasher.h" #include "src/zone/zone-list-inl.h" // The following header includes the write barrier essentials that can also be // used stand-alone without including heap-inl.h. // TODO(mlippautz): Remove once users of object-macros.h include this file on // their own. #include "src/heap/heap-write-barrier-inl.h" namespace v8 { namespace internal { AllocationSpace AllocationResult::RetrySpace() { DCHECK(IsRetry()); return static_cast(Smi::ToInt(object_)); } HeapObject* AllocationResult::ToObjectChecked() { CHECK(!IsRetry()); return HeapObject::cast(object_); } #define ROOT_ACCESSOR(type, name, camel_name) \ type* Heap::name() { return type::cast(roots_[k##camel_name##RootIndex]); } MUTABLE_ROOT_LIST(ROOT_ACCESSOR) #undef ROOT_ACCESSOR #define DATA_HANDLER_MAP_ACCESSOR(NAME, Name, Size, name) \ Map* Heap::name##_map() { \ return Map::cast(roots_[k##Name##Size##MapRootIndex]); \ } DATA_HANDLER_LIST(DATA_HANDLER_MAP_ACCESSOR) #undef DATA_HANDLER_MAP_ACCESSOR #define ACCESSOR_INFO_ACCESSOR(accessor_name, AccessorName) \ AccessorInfo* Heap::accessor_name##_accessor() { \ return AccessorInfo::cast(roots_[k##AccessorName##AccessorRootIndex]); \ } ACCESSOR_INFO_LIST(ACCESSOR_INFO_ACCESSOR) #undef ACCESSOR_INFO_ACCESSOR #define ROOT_ACCESSOR(type, name, camel_name) \ void Heap::set_##name(type* value) { \ /* The deserializer makes use of the fact that these common roots are */ \ /* never in new space and never on a page that is being compacted. */ \ DCHECK(!deserialization_complete() || \ RootCanBeWrittenAfterInitialization(k##camel_name##RootIndex)); \ DCHECK(k##camel_name##RootIndex >= kOldSpaceRoots || !InNewSpace(value)); \ roots_[k##camel_name##RootIndex] = value; \ } ROOT_LIST(ROOT_ACCESSOR) #undef ROOT_ACCESSOR PagedSpace* Heap::paged_space(int idx) { DCHECK_NE(idx, LO_SPACE); DCHECK_NE(idx, NEW_SPACE); return static_cast(space_[idx]); } Space* Heap::space(int idx) { return space_[idx]; } Address* Heap::NewSpaceAllocationTopAddress() { return new_space_->allocation_top_address(); } Address* Heap::NewSpaceAllocationLimitAddress() { return new_space_->allocation_limit_address(); } Address* Heap::OldSpaceAllocationTopAddress() { return old_space_->allocation_top_address(); } Address* Heap::OldSpaceAllocationLimitAddress() { return old_space_->allocation_limit_address(); } void Heap::UpdateNewSpaceAllocationCounter() { new_space_allocation_counter_ = NewSpaceAllocationCounter(); } size_t Heap::NewSpaceAllocationCounter() { return new_space_allocation_counter_ + new_space()->AllocatedSinceLastGC(); } AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationSpace space, AllocationAlignment alignment) { DCHECK(AllowHandleAllocation::IsAllowed()); DCHECK(AllowHeapAllocation::IsAllowed()); DCHECK(gc_state_ == NOT_IN_GC); #ifdef V8_ENABLE_ALLOCATION_TIMEOUT if (FLAG_random_gc_interval > 0 || FLAG_gc_interval >= 0) { if (!always_allocate() && Heap::allocation_timeout_-- <= 0) { return AllocationResult::Retry(space); } } #endif #ifdef DEBUG isolate_->counters()->objs_since_last_full()->Increment(); isolate_->counters()->objs_since_last_young()->Increment(); #endif bool large_object = size_in_bytes > kMaxRegularHeapObjectSize; bool new_large_object = FLAG_young_generation_large_objects && size_in_bytes > kMaxNewSpaceHeapObjectSize; HeapObject* object = nullptr; AllocationResult allocation; if (NEW_SPACE == space) { if (large_object) { space = LO_SPACE; } else { if (new_large_object) { allocation = new_lo_space_->AllocateRaw(size_in_bytes); } else { allocation = new_space_->AllocateRaw(size_in_bytes, alignment); } if (allocation.To(&object)) { OnAllocationEvent(object, size_in_bytes); } return allocation; } } // Here we only allocate in the old generation. if (OLD_SPACE == space) { if (large_object) { allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE); } else { allocation = old_space_->AllocateRaw(size_in_bytes, alignment); } } else if (CODE_SPACE == space) { if (size_in_bytes <= code_space()->AreaSize()) { allocation = code_space_->AllocateRawUnaligned(size_in_bytes); } else { allocation = lo_space_->AllocateRaw(size_in_bytes, EXECUTABLE); } } else if (LO_SPACE == space) { DCHECK(large_object); allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE); } else if (MAP_SPACE == space) { allocation = map_space_->AllocateRawUnaligned(size_in_bytes); } else if (RO_SPACE == space) { #ifdef V8_USE_SNAPSHOT DCHECK(isolate_->serializer_enabled()); #endif DCHECK(!large_object); DCHECK(CanAllocateInReadOnlySpace()); allocation = read_only_space_->AllocateRaw(size_in_bytes, alignment); } else { // NEW_SPACE is not allowed here. UNREACHABLE(); } if (allocation.To(&object)) { if (space == CODE_SPACE) { // Unprotect the memory chunk of the object if it was not unprotected // already. UnprotectAndRegisterMemoryChunk(object); ZapCodeObject(object->address(), size_in_bytes); } OnAllocationEvent(object, size_in_bytes); } return allocation; } void Heap::OnAllocationEvent(HeapObject* object, int size_in_bytes) { for (auto& tracker : allocation_trackers_) { tracker->AllocationEvent(object->address(), size_in_bytes); } if (FLAG_verify_predictable) { ++allocations_count_; // Advance synthetic time by making a time request. MonotonicallyIncreasingTimeInMs(); UpdateAllocationsHash(object); UpdateAllocationsHash(size_in_bytes); if (allocations_count_ % FLAG_dump_allocations_digest_at_alloc == 0) { PrintAllocationsHash(); } } else if (FLAG_fuzzer_gc_analysis) { ++allocations_count_; } else if (FLAG_trace_allocation_stack_interval > 0) { ++allocations_count_; if (allocations_count_ % FLAG_trace_allocation_stack_interval == 0) { isolate()->PrintStack(stdout, Isolate::kPrintStackConcise); } } } void Heap::OnMoveEvent(HeapObject* target, HeapObject* source, int size_in_bytes) { HeapProfiler* heap_profiler = isolate_->heap_profiler(); if (heap_profiler->is_tracking_object_moves()) { heap_profiler->ObjectMoveEvent(source->address(), target->address(), size_in_bytes); } for (auto& tracker : allocation_trackers_) { tracker->MoveEvent(source->address(), target->address(), size_in_bytes); } if (target->IsSharedFunctionInfo()) { LOG_CODE_EVENT(isolate_, SharedFunctionInfoMoveEvent(source->address(), target->address())); } if (FLAG_verify_predictable) { ++allocations_count_; // Advance synthetic time by making a time request. MonotonicallyIncreasingTimeInMs(); UpdateAllocationsHash(source); UpdateAllocationsHash(target); UpdateAllocationsHash(size_in_bytes); if (allocations_count_ % FLAG_dump_allocations_digest_at_alloc == 0) { PrintAllocationsHash(); } } else if (FLAG_fuzzer_gc_analysis) { ++allocations_count_; } } bool Heap::CanAllocateInReadOnlySpace() { return !deserialization_complete_ && (isolate()->serializer_enabled() || !isolate()->initialized_from_snapshot()); } void Heap::UpdateAllocationsHash(HeapObject* object) { Address object_address = object->address(); MemoryChunk* memory_chunk = MemoryChunk::FromAddress(object_address); AllocationSpace allocation_space = memory_chunk->owner()->identity(); STATIC_ASSERT(kSpaceTagSize + kPageSizeBits <= 32); uint32_t value = static_cast(object_address - memory_chunk->address()) | (static_cast(allocation_space) << kPageSizeBits); UpdateAllocationsHash(value); } void Heap::UpdateAllocationsHash(uint32_t value) { uint16_t c1 = static_cast(value); uint16_t c2 = static_cast(value >> 16); raw_allocations_hash_ = StringHasher::AddCharacterCore(raw_allocations_hash_, c1); raw_allocations_hash_ = StringHasher::AddCharacterCore(raw_allocations_hash_, c2); } void Heap::RegisterExternalString(String* string) { DCHECK(string->IsExternalString()); DCHECK(!string->IsThinString()); external_string_table_.AddString(string); } void Heap::UpdateExternalString(String* string, size_t old_payload, size_t new_payload) { DCHECK(string->IsExternalString()); Page* page = Page::FromHeapObject(string); if (old_payload > new_payload) page->DecrementExternalBackingStoreBytes( ExternalBackingStoreType::kExternalString, old_payload - new_payload); else page->IncrementExternalBackingStoreBytes( ExternalBackingStoreType::kExternalString, new_payload - old_payload); } void Heap::FinalizeExternalString(String* string) { DCHECK(string->IsExternalString()); Page* page = Page::FromHeapObject(string); ExternalString* ext_string = ExternalString::cast(string); page->DecrementExternalBackingStoreBytes( ExternalBackingStoreType::kExternalString, ext_string->ExternalPayloadSize()); v8::String::ExternalStringResourceBase** resource_addr = reinterpret_cast( reinterpret_cast(string) + ExternalString::kResourceOffset - kHeapObjectTag); // Dispose of the C++ object if it has not already been disposed. if (*resource_addr != nullptr) { (*resource_addr)->Dispose(); *resource_addr = nullptr; } } Address Heap::NewSpaceTop() { return new_space_->top(); } // static bool Heap::InNewSpace(Object* object) { DCHECK(!HasWeakHeapObjectTag(object)); return object->IsHeapObject() && InNewSpace(HeapObject::cast(object)); } // static bool Heap::InNewSpace(MaybeObject* object) { HeapObject* heap_object; return object->ToStrongOrWeakHeapObject(&heap_object) && InNewSpace(heap_object); } // static bool Heap::InNewSpace(HeapObject* heap_object) { // Inlined check from NewSpace::Contains. bool result = MemoryChunk::FromHeapObject(heap_object)->InNewSpace(); #ifdef DEBUG // If in NEW_SPACE, then check we're either not in the middle of GC or the // object is in to-space. if (result) { // If the object is in NEW_SPACE, then it's not in RO_SPACE so this is safe. Heap* heap = Heap::FromWritableHeapObject(heap_object); DCHECK(heap->gc_state_ != NOT_IN_GC || InToSpace(heap_object)); } #endif return result; } // static bool Heap::InFromSpace(Object* object) { DCHECK(!HasWeakHeapObjectTag(object)); return object->IsHeapObject() && InFromSpace(HeapObject::cast(object)); } // static bool Heap::InFromSpace(MaybeObject* object) { HeapObject* heap_object; return object->ToStrongOrWeakHeapObject(&heap_object) && InFromSpace(heap_object); } // static bool Heap::InFromSpace(HeapObject* heap_object) { return MemoryChunk::FromHeapObject(heap_object) ->IsFlagSet(Page::IN_FROM_SPACE); } // static bool Heap::InToSpace(Object* object) { DCHECK(!HasWeakHeapObjectTag(object)); return object->IsHeapObject() && InToSpace(HeapObject::cast(object)); } // static bool Heap::InToSpace(MaybeObject* object) { HeapObject* heap_object; return object->ToStrongOrWeakHeapObject(&heap_object) && InToSpace(heap_object); } // static bool Heap::InToSpace(HeapObject* heap_object) { return MemoryChunk::FromHeapObject(heap_object)->IsFlagSet(Page::IN_TO_SPACE); } bool Heap::InOldSpace(Object* object) { return old_space_->Contains(object); } bool Heap::InReadOnlySpace(Object* object) { return read_only_space_->Contains(object); } bool Heap::InNewSpaceSlow(Address address) { return new_space_->ContainsSlow(address); } bool Heap::InOldSpaceSlow(Address address) { return old_space_->ContainsSlow(address); } // static Heap* Heap::FromWritableHeapObject(const HeapObject* obj) { MemoryChunk* chunk = MemoryChunk::FromHeapObject(obj); // RO_SPACE can be shared between heaps, so we can't use RO_SPACE objects to // find a heap. The exception is when the ReadOnlySpace is writeable, during // bootstrapping, so explicitly allow this case. SLOW_DCHECK(chunk->owner()->identity() != RO_SPACE || static_cast(chunk->owner())->writable()); Heap* heap = chunk->heap(); SLOW_DCHECK(heap != nullptr); return heap; } bool Heap::ShouldBePromoted(Address old_address) { Page* page = Page::FromAddress(old_address); Address age_mark = new_space_->age_mark(); return page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK) && (!page->ContainsLimit(age_mark) || old_address < age_mark); } void Heap::CopyBlock(Address dst, Address src, int byte_size) { CopyWords(reinterpret_cast(dst), reinterpret_cast(src), static_cast(byte_size / kPointerSize)); } template AllocationMemento* Heap::FindAllocationMemento(Map* map, HeapObject* object) { Address object_address = object->address(); Address memento_address = object_address + object->SizeFromMap(map); Address last_memento_word_address = memento_address + kPointerSize; // If the memento would be on another page, bail out immediately. if (!Page::OnSamePage(object_address, last_memento_word_address)) { return nullptr; } HeapObject* candidate = HeapObject::FromAddress(memento_address); Map* candidate_map = candidate->map(); // This fast check may peek at an uninitialized word. However, the slow check // below (memento_address == top) ensures that this is safe. Mark the word as // initialized to silence MemorySanitizer warnings. MSAN_MEMORY_IS_INITIALIZED(&candidate_map, sizeof(candidate_map)); if (candidate_map != ReadOnlyRoots(this).allocation_memento_map()) { return nullptr; } // Bail out if the memento is below the age mark, which can happen when // mementos survived because a page got moved within new space. Page* object_page = Page::FromAddress(object_address); if (object_page->IsFlagSet(Page::NEW_SPACE_BELOW_AGE_MARK)) { Address age_mark = reinterpret_cast(object_page->owner())->age_mark(); if (!object_page->Contains(age_mark)) { return nullptr; } // Do an exact check in the case where the age mark is on the same page. if (object_address < age_mark) { return nullptr; } } AllocationMemento* memento_candidate = AllocationMemento::cast(candidate); // Depending on what the memento is used for, we might need to perform // additional checks. Address top; switch (mode) { case Heap::kForGC: return memento_candidate; case Heap::kForRuntime: if (memento_candidate == nullptr) return nullptr; // Either the object is the last object in the new space, or there is // another object of at least word size (the header map word) following // it, so suffices to compare ptr and top here. top = NewSpaceTop(); DCHECK(memento_address == top || memento_address + HeapObject::kHeaderSize <= top || !Page::OnSamePage(memento_address, top - 1)); if ((memento_address != top) && memento_candidate->IsValid()) { return memento_candidate; } return nullptr; default: UNREACHABLE(); } UNREACHABLE(); } void Heap::UpdateAllocationSite(Map* map, HeapObject* object, PretenuringFeedbackMap* pretenuring_feedback) { DCHECK_NE(pretenuring_feedback, &global_pretenuring_feedback_); DCHECK( InFromSpace(object) || (InToSpace(object) && Page::FromAddress(object->address()) ->IsFlagSet(Page::PAGE_NEW_NEW_PROMOTION)) || (!InNewSpace(object) && Page::FromAddress(object->address()) ->IsFlagSet(Page::PAGE_NEW_OLD_PROMOTION))); if (!FLAG_allocation_site_pretenuring || !AllocationSite::CanTrack(map->instance_type())) return; AllocationMemento* memento_candidate = FindAllocationMemento(map, object); if (memento_candidate == nullptr) return; // Entering cached feedback is used in the parallel case. We are not allowed // to dereference the allocation site and rather have to postpone all checks // till actually merging the data. Address key = memento_candidate->GetAllocationSiteUnchecked(); (*pretenuring_feedback)[reinterpret_cast(key)]++; } Isolate* Heap::isolate() { return reinterpret_cast( reinterpret_cast(this) - reinterpret_cast(reinterpret_cast(16)->heap()) + 16); } void Heap::ExternalStringTable::AddString(String* string) { DCHECK(string->IsExternalString()); DCHECK(!Contains(string)); if (InNewSpace(string)) { new_space_strings_.push_back(string); } else { old_space_strings_.push_back(string); } } Oddball* Heap::ToBoolean(bool condition) { ReadOnlyRoots roots(this); return condition ? roots.true_value() : roots.false_value(); } uint64_t Heap::HashSeed() { uint64_t seed; hash_seed()->copy_out(0, reinterpret_cast(&seed), kInt64Size); DCHECK(FLAG_randomize_hashes || seed == 0); return seed; } int Heap::NextScriptId() { int last_id = last_script_id()->value(); if (last_id == Smi::kMaxValue) last_id = v8::UnboundScript::kNoScriptId; last_id++; set_last_script_id(Smi::FromInt(last_id)); return last_id; } int Heap::NextDebuggingId() { int last_id = last_debugging_id()->value(); if (last_id == DebugInfo::DebuggingIdBits::kMax) { last_id = DebugInfo::kNoDebuggingId; } last_id++; set_last_debugging_id(Smi::FromInt(last_id)); return last_id; } int Heap::GetNextTemplateSerialNumber() { int next_serial_number = next_template_serial_number()->value() + 1; set_next_template_serial_number(Smi::FromInt(next_serial_number)); return next_serial_number; } int Heap::MaxNumberToStringCacheSize() const { // Compute the size of the number string cache based on the max newspace size. // The number string cache has a minimum size based on twice the initial cache // size to ensure that it is bigger after being made 'full size'. size_t number_string_cache_size = max_semi_space_size_ / 512; number_string_cache_size = Max(static_cast(kInitialNumberStringCacheSize * 2), Min(0x4000u, number_string_cache_size)); // There is a string and a number per entry so the length is twice the number // of entries. return static_cast(number_string_cache_size * 2); } AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate) : heap_(isolate->heap()) { heap_->always_allocate_scope_count_++; } AlwaysAllocateScope::~AlwaysAllocateScope() { heap_->always_allocate_scope_count_--; } CodeSpaceMemoryModificationScope::CodeSpaceMemoryModificationScope(Heap* heap) : heap_(heap) { if (heap_->write_protect_code_memory()) { heap_->increment_code_space_memory_modification_scope_depth(); heap_->code_space()->SetReadAndWritable(); LargePage* page = heap_->lo_space()->first_page(); while (page != nullptr) { if (page->IsFlagSet(MemoryChunk::IS_EXECUTABLE)) { CHECK(heap_->memory_allocator()->IsMemoryChunkExecutable(page)); page->SetReadAndWritable(); } page = page->next_page(); } } } CodeSpaceMemoryModificationScope::~CodeSpaceMemoryModificationScope() { if (heap_->write_protect_code_memory()) { heap_->decrement_code_space_memory_modification_scope_depth(); heap_->code_space()->SetReadAndExecutable(); LargePage* page = heap_->lo_space()->first_page(); while (page != nullptr) { if (page->IsFlagSet(MemoryChunk::IS_EXECUTABLE)) { CHECK(heap_->memory_allocator()->IsMemoryChunkExecutable(page)); page->SetReadAndExecutable(); } page = page->next_page(); } } } CodePageCollectionMemoryModificationScope:: CodePageCollectionMemoryModificationScope(Heap* heap) : heap_(heap) { if (heap_->write_protect_code_memory() && !heap_->code_space_memory_modification_scope_depth()) { heap_->EnableUnprotectedMemoryChunksRegistry(); } } CodePageCollectionMemoryModificationScope:: ~CodePageCollectionMemoryModificationScope() { if (heap_->write_protect_code_memory() && !heap_->code_space_memory_modification_scope_depth()) { heap_->ProtectUnprotectedMemoryChunks(); heap_->DisableUnprotectedMemoryChunksRegistry(); } } CodePageMemoryModificationScope::CodePageMemoryModificationScope( MemoryChunk* chunk) : chunk_(chunk), scope_active_(chunk_->heap()->write_protect_code_memory() && chunk_->IsFlagSet(MemoryChunk::IS_EXECUTABLE)) { if (scope_active_) { DCHECK(chunk_->owner()->identity() == CODE_SPACE || (chunk_->owner()->identity() == LO_SPACE && chunk_->IsFlagSet(MemoryChunk::IS_EXECUTABLE))); chunk_->SetReadAndWritable(); } } CodePageMemoryModificationScope::~CodePageMemoryModificationScope() { if (scope_active_) { chunk_->SetReadAndExecutable(); } } } // namespace internal } // namespace v8 #endif // V8_HEAP_HEAP_INL_H_