| // 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. |
| |
| #include "src/heap/heap.h" |
| |
| #include "src/accessors.h" |
| #include "src/api.h" |
| #include "src/ast/context-slot-cache.h" |
| #include "src/base/bits.h" |
| #include "src/base/once.h" |
| #include "src/base/utils/random-number-generator.h" |
| #include "src/bootstrapper.h" |
| #include "src/codegen.h" |
| #include "src/compilation-cache.h" |
| #include "src/compiler-dispatcher/optimizing-compile-dispatcher.h" |
| #include "src/conversions.h" |
| #include "src/debug/debug.h" |
| #include "src/deoptimizer.h" |
| #include "src/feedback-vector.h" |
| #include "src/global-handles.h" |
| #include "src/heap/array-buffer-tracker-inl.h" |
| #include "src/heap/code-stats.h" |
| #include "src/heap/embedder-tracing.h" |
| #include "src/heap/gc-idle-time-handler.h" |
| #include "src/heap/gc-tracer.h" |
| #include "src/heap/incremental-marking.h" |
| #include "src/heap/mark-compact-inl.h" |
| #include "src/heap/mark-compact.h" |
| #include "src/heap/memory-reducer.h" |
| #include "src/heap/object-stats.h" |
| #include "src/heap/objects-visiting-inl.h" |
| #include "src/heap/objects-visiting.h" |
| #include "src/heap/remembered-set.h" |
| #include "src/heap/scavenge-job.h" |
| #include "src/heap/scavenger-inl.h" |
| #include "src/heap/store-buffer.h" |
| #include "src/interpreter/interpreter.h" |
| #include "src/regexp/jsregexp.h" |
| #include "src/runtime-profiler.h" |
| #include "src/snapshot/natives.h" |
| #include "src/snapshot/serializer-common.h" |
| #include "src/snapshot/snapshot.h" |
| #include "src/tracing/trace-event.h" |
| #include "src/utils.h" |
| #include "src/v8.h" |
| #include "src/v8threads.h" |
| #include "src/vm-state-inl.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| struct Heap::StrongRootsList { |
| Object** start; |
| Object** end; |
| StrongRootsList* next; |
| }; |
| |
| class IdleScavengeObserver : public AllocationObserver { |
| public: |
| IdleScavengeObserver(Heap& heap, intptr_t step_size) |
| : AllocationObserver(step_size), heap_(heap) {} |
| |
| void Step(int bytes_allocated, Address, size_t) override { |
| heap_.ScheduleIdleScavengeIfNeeded(bytes_allocated); |
| } |
| |
| private: |
| Heap& heap_; |
| }; |
| |
| Heap::Heap() |
| : external_memory_(0), |
| external_memory_limit_(kExternalAllocationSoftLimit), |
| external_memory_at_last_mark_compact_(0), |
| isolate_(nullptr), |
| code_range_size_(0), |
| // semispace_size_ should be a power of 2 and old_generation_size_ should |
| // be a multiple of Page::kPageSize. |
| max_semi_space_size_(8 * (kPointerSize / 4) * MB), |
| initial_semispace_size_(MB), |
| max_old_generation_size_(700ul * (kPointerSize / 4) * MB), |
| initial_max_old_generation_size_(max_old_generation_size_), |
| initial_old_generation_size_(max_old_generation_size_ / |
| kInitalOldGenerationLimitFactor), |
| old_generation_size_configured_(false), |
| max_executable_size_(256ul * (kPointerSize / 4) * MB), |
| // Variables set based on semispace_size_ and old_generation_size_ in |
| // ConfigureHeap. |
| // Will be 4 * reserved_semispace_size_ to ensure that young |
| // generation can be aligned to its size. |
| maximum_committed_(0), |
| survived_since_last_expansion_(0), |
| survived_last_scavenge_(0), |
| always_allocate_scope_count_(0), |
| memory_pressure_level_(MemoryPressureLevel::kNone), |
| out_of_memory_callback_(nullptr), |
| out_of_memory_callback_data_(nullptr), |
| contexts_disposed_(0), |
| number_of_disposed_maps_(0), |
| global_ic_age_(0), |
| new_space_(nullptr), |
| old_space_(NULL), |
| code_space_(NULL), |
| map_space_(NULL), |
| lo_space_(NULL), |
| gc_state_(NOT_IN_GC), |
| gc_post_processing_depth_(0), |
| allocations_count_(0), |
| raw_allocations_hash_(0), |
| ms_count_(0), |
| gc_count_(0), |
| remembered_unmapped_pages_index_(0), |
| #ifdef DEBUG |
| allocation_timeout_(0), |
| #endif // DEBUG |
| old_generation_allocation_limit_(initial_old_generation_size_), |
| inline_allocation_disabled_(false), |
| tracer_(nullptr), |
| promoted_objects_size_(0), |
| promotion_ratio_(0), |
| semi_space_copied_object_size_(0), |
| previous_semi_space_copied_object_size_(0), |
| semi_space_copied_rate_(0), |
| nodes_died_in_new_space_(0), |
| nodes_copied_in_new_space_(0), |
| nodes_promoted_(0), |
| maximum_size_scavenges_(0), |
| last_idle_notification_time_(0.0), |
| last_gc_time_(0.0), |
| scavenge_collector_(nullptr), |
| mark_compact_collector_(nullptr), |
| memory_allocator_(nullptr), |
| store_buffer_(nullptr), |
| incremental_marking_(nullptr), |
| gc_idle_time_handler_(nullptr), |
| memory_reducer_(nullptr), |
| live_object_stats_(nullptr), |
| dead_object_stats_(nullptr), |
| scavenge_job_(nullptr), |
| idle_scavenge_observer_(nullptr), |
| new_space_allocation_counter_(0), |
| old_generation_allocation_counter_at_last_gc_(0), |
| old_generation_size_at_last_gc_(0), |
| gcs_since_last_deopt_(0), |
| global_pretenuring_feedback_(nullptr), |
| ring_buffer_full_(false), |
| ring_buffer_end_(0), |
| promotion_queue_(this), |
| configured_(false), |
| current_gc_flags_(Heap::kNoGCFlags), |
| current_gc_callback_flags_(GCCallbackFlags::kNoGCCallbackFlags), |
| external_string_table_(this), |
| gc_callbacks_depth_(0), |
| deserialization_complete_(false), |
| strong_roots_list_(NULL), |
| heap_iterator_depth_(0), |
| local_embedder_heap_tracer_(nullptr), |
| force_oom_(false), |
| delay_sweeper_tasks_for_testing_(false) { |
| // Allow build-time customization of the max semispace size. Building |
| // V8 with snapshots and a non-default max semispace size is much |
| // easier if you can define it as part of the build environment. |
| #if defined(V8_MAX_SEMISPACE_SIZE) |
| max_semi_space_size_ = reserved_semispace_size_ = V8_MAX_SEMISPACE_SIZE; |
| #endif |
| |
| // Ensure old_generation_size_ is a multiple of kPageSize. |
| DCHECK((max_old_generation_size_ & (Page::kPageSize - 1)) == 0); |
| |
| memset(roots_, 0, sizeof(roots_[0]) * kRootListLength); |
| set_native_contexts_list(NULL); |
| set_allocation_sites_list(Smi::kZero); |
| set_encountered_weak_collections(Smi::kZero); |
| set_encountered_weak_cells(Smi::kZero); |
| set_encountered_transition_arrays(Smi::kZero); |
| // Put a dummy entry in the remembered pages so we can find the list the |
| // minidump even if there are no real unmapped pages. |
| RememberUnmappedPage(NULL, false); |
| } |
| |
| size_t Heap::Capacity() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return new_space_->Capacity() + OldGenerationCapacity(); |
| } |
| |
| size_t Heap::OldGenerationCapacity() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return old_space_->Capacity() + code_space_->Capacity() + |
| map_space_->Capacity() + lo_space_->SizeOfObjects(); |
| } |
| |
| size_t Heap::CommittedOldGenerationMemory() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return old_space_->CommittedMemory() + code_space_->CommittedMemory() + |
| map_space_->CommittedMemory() + lo_space_->Size(); |
| } |
| |
| size_t Heap::CommittedMemory() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return new_space_->CommittedMemory() + CommittedOldGenerationMemory(); |
| } |
| |
| |
| size_t Heap::CommittedPhysicalMemory() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return new_space_->CommittedPhysicalMemory() + |
| old_space_->CommittedPhysicalMemory() + |
| code_space_->CommittedPhysicalMemory() + |
| map_space_->CommittedPhysicalMemory() + |
| lo_space_->CommittedPhysicalMemory(); |
| } |
| |
| size_t Heap::CommittedMemoryExecutable() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return static_cast<size_t>(memory_allocator()->SizeExecutable()); |
| } |
| |
| |
| void Heap::UpdateMaximumCommitted() { |
| if (!HasBeenSetUp()) return; |
| |
| const size_t current_committed_memory = CommittedMemory(); |
| if (current_committed_memory > maximum_committed_) { |
| maximum_committed_ = current_committed_memory; |
| } |
| } |
| |
| size_t Heap::Available() { |
| if (!HasBeenSetUp()) return 0; |
| |
| size_t total = 0; |
| AllSpaces spaces(this); |
| for (Space* space = spaces.next(); space != NULL; space = spaces.next()) { |
| total += space->Available(); |
| } |
| return total; |
| } |
| |
| |
| bool Heap::HasBeenSetUp() { |
| return old_space_ != NULL && code_space_ != NULL && map_space_ != NULL && |
| lo_space_ != NULL; |
| } |
| |
| |
| GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space, |
| const char** reason) { |
| // Is global GC requested? |
| if (space != NEW_SPACE) { |
| isolate_->counters()->gc_compactor_caused_by_request()->Increment(); |
| *reason = "GC in old space requested"; |
| return MARK_COMPACTOR; |
| } |
| |
| if (FLAG_gc_global || (FLAG_stress_compaction && (gc_count_ & 1) != 0)) { |
| *reason = "GC in old space forced by flags"; |
| return MARK_COMPACTOR; |
| } |
| |
| if (incremental_marking()->NeedsFinalization() && |
| AllocationLimitOvershotByLargeMargin()) { |
| *reason = "Incremental marking needs finalization"; |
| return MARK_COMPACTOR; |
| } |
| |
| // Is there enough space left in OLD to guarantee that a scavenge can |
| // succeed? |
| // |
| // Note that MemoryAllocator->MaxAvailable() undercounts the memory available |
| // for object promotion. It counts only the bytes that the memory |
| // allocator has not yet allocated from the OS and assigned to any space, |
| // and does not count available bytes already in the old space or code |
| // space. Undercounting is safe---we may get an unrequested full GC when |
| // a scavenge would have succeeded. |
| if (memory_allocator()->MaxAvailable() <= new_space_->Size()) { |
| isolate_->counters() |
| ->gc_compactor_caused_by_oldspace_exhaustion() |
| ->Increment(); |
| *reason = "scavenge might not succeed"; |
| return MARK_COMPACTOR; |
| } |
| |
| // Default |
| *reason = NULL; |
| return YoungGenerationCollector(); |
| } |
| |
| void Heap::SetGCState(HeapState state) { |
| gc_state_ = state; |
| } |
| |
| // TODO(1238405): Combine the infrastructure for --heap-stats and |
| // --log-gc to avoid the complicated preprocessor and flag testing. |
| void Heap::ReportStatisticsBeforeGC() { |
| // Heap::ReportHeapStatistics will also log NewSpace statistics when |
| // compiled --log-gc is set. The following logic is used to avoid |
| // double logging. |
| #ifdef DEBUG |
| if (FLAG_heap_stats || FLAG_log_gc) new_space_->CollectStatistics(); |
| if (FLAG_heap_stats) { |
| ReportHeapStatistics("Before GC"); |
| } else if (FLAG_log_gc) { |
| new_space_->ReportStatistics(); |
| } |
| if (FLAG_heap_stats || FLAG_log_gc) new_space_->ClearHistograms(); |
| #else |
| if (FLAG_log_gc) { |
| new_space_->CollectStatistics(); |
| new_space_->ReportStatistics(); |
| new_space_->ClearHistograms(); |
| } |
| #endif // DEBUG |
| } |
| |
| |
| void Heap::PrintShortHeapStatistics() { |
| if (!FLAG_trace_gc_verbose) return; |
| PrintIsolate(isolate_, "Memory allocator, used: %6" PRIuS |
| " KB," |
| " available: %6" PRIuS " KB\n", |
| memory_allocator()->Size() / KB, |
| memory_allocator()->Available() / KB); |
| PrintIsolate(isolate_, "New space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| new_space_->Size() / KB, new_space_->Available() / KB, |
| new_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "Old space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| old_space_->SizeOfObjects() / KB, old_space_->Available() / KB, |
| old_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "Code space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS "KB\n", |
| code_space_->SizeOfObjects() / KB, code_space_->Available() / KB, |
| code_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "Map space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| map_space_->SizeOfObjects() / KB, map_space_->Available() / KB, |
| map_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "Large object space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| lo_space_->SizeOfObjects() / KB, lo_space_->Available() / KB, |
| lo_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "All spaces, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS "KB\n", |
| this->SizeOfObjects() / KB, this->Available() / KB, |
| this->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "External memory reported: %6" PRId64 " KB\n", |
| external_memory_ / KB); |
| PrintIsolate(isolate_, "Total time spent in GC : %.1f ms\n", |
| total_gc_time_ms_); |
| } |
| |
| // TODO(1238405): Combine the infrastructure for --heap-stats and |
| // --log-gc to avoid the complicated preprocessor and flag testing. |
| void Heap::ReportStatisticsAfterGC() { |
| // Similar to the before GC, we use some complicated logic to ensure that |
| // NewSpace statistics are logged exactly once when --log-gc is turned on. |
| #if defined(DEBUG) |
| if (FLAG_heap_stats) { |
| new_space_->CollectStatistics(); |
| ReportHeapStatistics("After GC"); |
| } else if (FLAG_log_gc) { |
| new_space_->ReportStatistics(); |
| } |
| #else |
| if (FLAG_log_gc) new_space_->ReportStatistics(); |
| #endif // DEBUG |
| for (int i = 0; i < static_cast<int>(v8::Isolate::kUseCounterFeatureCount); |
| ++i) { |
| int count = deferred_counters_[i]; |
| deferred_counters_[i] = 0; |
| while (count > 0) { |
| count--; |
| isolate()->CountUsage(static_cast<v8::Isolate::UseCounterFeature>(i)); |
| } |
| } |
| } |
| |
| |
| void Heap::IncrementDeferredCount(v8::Isolate::UseCounterFeature feature) { |
| deferred_counters_[feature]++; |
| } |
| |
| bool Heap::UncommitFromSpace() { return new_space_->UncommitFromSpace(); } |
| |
| void Heap::GarbageCollectionPrologue() { |
| { |
| AllowHeapAllocation for_the_first_part_of_prologue; |
| gc_count_++; |
| |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| } |
| |
| // Reset GC statistics. |
| promoted_objects_size_ = 0; |
| previous_semi_space_copied_object_size_ = semi_space_copied_object_size_; |
| semi_space_copied_object_size_ = 0; |
| nodes_died_in_new_space_ = 0; |
| nodes_copied_in_new_space_ = 0; |
| nodes_promoted_ = 0; |
| |
| UpdateMaximumCommitted(); |
| |
| #ifdef DEBUG |
| DCHECK(!AllowHeapAllocation::IsAllowed() && gc_state_ == NOT_IN_GC); |
| |
| if (FLAG_gc_verbose) Print(); |
| |
| ReportStatisticsBeforeGC(); |
| #endif // DEBUG |
| |
| if (new_space_->IsAtMaximumCapacity()) { |
| maximum_size_scavenges_++; |
| } else { |
| maximum_size_scavenges_ = 0; |
| } |
| CheckNewSpaceExpansionCriteria(); |
| UpdateNewSpaceAllocationCounter(); |
| } |
| |
| size_t Heap::SizeOfObjects() { |
| size_t total = 0; |
| AllSpaces spaces(this); |
| for (Space* space = spaces.next(); space != NULL; space = spaces.next()) { |
| total += space->SizeOfObjects(); |
| } |
| return total; |
| } |
| |
| |
| const char* Heap::GetSpaceName(int idx) { |
| switch (idx) { |
| case NEW_SPACE: |
| return "new_space"; |
| case OLD_SPACE: |
| return "old_space"; |
| case MAP_SPACE: |
| return "map_space"; |
| case CODE_SPACE: |
| return "code_space"; |
| case LO_SPACE: |
| return "large_object_space"; |
| default: |
| UNREACHABLE(); |
| } |
| return nullptr; |
| } |
| |
| |
| void Heap::RepairFreeListsAfterDeserialization() { |
| PagedSpaces spaces(this); |
| for (PagedSpace* space = spaces.next(); space != NULL; |
| space = spaces.next()) { |
| space->RepairFreeListsAfterDeserialization(); |
| } |
| } |
| |
| void Heap::MergeAllocationSitePretenuringFeedback( |
| const base::HashMap& local_pretenuring_feedback) { |
| AllocationSite* site = nullptr; |
| for (base::HashMap::Entry* local_entry = local_pretenuring_feedback.Start(); |
| local_entry != nullptr; |
| local_entry = local_pretenuring_feedback.Next(local_entry)) { |
| site = reinterpret_cast<AllocationSite*>(local_entry->key); |
| MapWord map_word = site->map_word(); |
| if (map_word.IsForwardingAddress()) { |
| site = AllocationSite::cast(map_word.ToForwardingAddress()); |
| } |
| |
| // We have not validated the allocation site yet, since we have not |
| // dereferenced the site during collecting information. |
| // This is an inlined check of AllocationMemento::IsValid. |
| if (!site->IsAllocationSite() || site->IsZombie()) continue; |
| |
| int value = |
| static_cast<int>(reinterpret_cast<intptr_t>(local_entry->value)); |
| DCHECK_GT(value, 0); |
| |
| if (site->IncrementMementoFoundCount(value)) { |
| global_pretenuring_feedback_->LookupOrInsert(site, |
| ObjectHash(site->address())); |
| } |
| } |
| } |
| |
| class Heap::SkipStoreBufferScope { |
| public: |
| explicit SkipStoreBufferScope(StoreBuffer* store_buffer) |
| : store_buffer_(store_buffer) { |
| store_buffer_->MoveAllEntriesToRememberedSet(); |
| store_buffer_->SetMode(StoreBuffer::IN_GC); |
| } |
| |
| ~SkipStoreBufferScope() { |
| DCHECK(store_buffer_->Empty()); |
| store_buffer_->SetMode(StoreBuffer::NOT_IN_GC); |
| } |
| |
| private: |
| StoreBuffer* store_buffer_; |
| }; |
| |
| class Heap::PretenuringScope { |
| public: |
| explicit PretenuringScope(Heap* heap) : heap_(heap) { |
| heap_->global_pretenuring_feedback_ = |
| new base::HashMap(kInitialFeedbackCapacity); |
| } |
| |
| ~PretenuringScope() { |
| delete heap_->global_pretenuring_feedback_; |
| heap_->global_pretenuring_feedback_ = nullptr; |
| } |
| |
| private: |
| Heap* heap_; |
| }; |
| |
| |
| void Heap::ProcessPretenuringFeedback() { |
| bool trigger_deoptimization = false; |
| if (FLAG_allocation_site_pretenuring) { |
| int tenure_decisions = 0; |
| int dont_tenure_decisions = 0; |
| int allocation_mementos_found = 0; |
| int allocation_sites = 0; |
| int active_allocation_sites = 0; |
| |
| AllocationSite* site = nullptr; |
| |
| // Step 1: Digest feedback for recorded allocation sites. |
| bool maximum_size_scavenge = MaximumSizeScavenge(); |
| for (base::HashMap::Entry* e = global_pretenuring_feedback_->Start(); |
| e != nullptr; e = global_pretenuring_feedback_->Next(e)) { |
| allocation_sites++; |
| site = reinterpret_cast<AllocationSite*>(e->key); |
| int found_count = site->memento_found_count(); |
| // An entry in the storage does not imply that the count is > 0 because |
| // allocation sites might have been reset due to too many objects dying |
| // in old space. |
| if (found_count > 0) { |
| DCHECK(site->IsAllocationSite()); |
| active_allocation_sites++; |
| allocation_mementos_found += found_count; |
| if (site->DigestPretenuringFeedback(maximum_size_scavenge)) { |
| trigger_deoptimization = true; |
| } |
| if (site->GetPretenureMode() == TENURED) { |
| tenure_decisions++; |
| } else { |
| dont_tenure_decisions++; |
| } |
| } |
| } |
| |
| // Step 2: Deopt maybe tenured allocation sites if necessary. |
| bool deopt_maybe_tenured = DeoptMaybeTenuredAllocationSites(); |
| if (deopt_maybe_tenured) { |
| Object* list_element = allocation_sites_list(); |
| while (list_element->IsAllocationSite()) { |
| site = AllocationSite::cast(list_element); |
| DCHECK(site->IsAllocationSite()); |
| allocation_sites++; |
| if (site->IsMaybeTenure()) { |
| site->set_deopt_dependent_code(true); |
| trigger_deoptimization = true; |
| } |
| list_element = site->weak_next(); |
| } |
| } |
| |
| if (trigger_deoptimization) { |
| isolate_->stack_guard()->RequestDeoptMarkedAllocationSites(); |
| } |
| |
| if (FLAG_trace_pretenuring_statistics && |
| (allocation_mementos_found > 0 || tenure_decisions > 0 || |
| dont_tenure_decisions > 0)) { |
| PrintIsolate(isolate(), |
| "pretenuring: deopt_maybe_tenured=%d visited_sites=%d " |
| "active_sites=%d " |
| "mementos=%d tenured=%d not_tenured=%d\n", |
| deopt_maybe_tenured ? 1 : 0, allocation_sites, |
| active_allocation_sites, allocation_mementos_found, |
| tenure_decisions, dont_tenure_decisions); |
| } |
| } |
| } |
| |
| |
| void Heap::DeoptMarkedAllocationSites() { |
| // TODO(hpayer): If iterating over the allocation sites list becomes a |
| // performance issue, use a cache data structure in heap instead. |
| Object* list_element = allocation_sites_list(); |
| while (list_element->IsAllocationSite()) { |
| AllocationSite* site = AllocationSite::cast(list_element); |
| if (site->deopt_dependent_code()) { |
| site->dependent_code()->MarkCodeForDeoptimization( |
| isolate_, DependentCode::kAllocationSiteTenuringChangedGroup); |
| site->set_deopt_dependent_code(false); |
| } |
| list_element = site->weak_next(); |
| } |
| Deoptimizer::DeoptimizeMarkedCode(isolate_); |
| } |
| |
| |
| void Heap::GarbageCollectionEpilogue() { |
| // In release mode, we only zap the from space under heap verification. |
| if (Heap::ShouldZapGarbage()) { |
| ZapFromSpace(); |
| } |
| |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| |
| AllowHeapAllocation for_the_rest_of_the_epilogue; |
| |
| #ifdef DEBUG |
| if (FLAG_print_global_handles) isolate_->global_handles()->Print(); |
| if (FLAG_print_handles) PrintHandles(); |
| if (FLAG_gc_verbose) Print(); |
| if (FLAG_code_stats) ReportCodeStatistics("After GC"); |
| if (FLAG_check_handle_count) CheckHandleCount(); |
| #endif |
| if (FLAG_deopt_every_n_garbage_collections > 0) { |
| // TODO(jkummerow/ulan/jarin): This is not safe! We can't assume that |
| // the topmost optimized frame can be deoptimized safely, because it |
| // might not have a lazy bailout point right after its current PC. |
| if (++gcs_since_last_deopt_ == FLAG_deopt_every_n_garbage_collections) { |
| Deoptimizer::DeoptimizeAll(isolate()); |
| gcs_since_last_deopt_ = 0; |
| } |
| } |
| |
| UpdateMaximumCommitted(); |
| |
| isolate_->counters()->alive_after_last_gc()->Set( |
| static_cast<int>(SizeOfObjects())); |
| |
| isolate_->counters()->string_table_capacity()->Set( |
| string_table()->Capacity()); |
| isolate_->counters()->number_of_symbols()->Set( |
| string_table()->NumberOfElements()); |
| |
| if (CommittedMemory() > 0) { |
| isolate_->counters()->external_fragmentation_total()->AddSample( |
| static_cast<int>(100 - (SizeOfObjects() * 100.0) / CommittedMemory())); |
| |
| isolate_->counters()->heap_fraction_new_space()->AddSample(static_cast<int>( |
| (new_space()->CommittedMemory() * 100.0) / CommittedMemory())); |
| isolate_->counters()->heap_fraction_old_space()->AddSample(static_cast<int>( |
| (old_space()->CommittedMemory() * 100.0) / CommittedMemory())); |
| isolate_->counters()->heap_fraction_code_space()->AddSample( |
| static_cast<int>((code_space()->CommittedMemory() * 100.0) / |
| CommittedMemory())); |
| isolate_->counters()->heap_fraction_map_space()->AddSample(static_cast<int>( |
| (map_space()->CommittedMemory() * 100.0) / CommittedMemory())); |
| isolate_->counters()->heap_fraction_lo_space()->AddSample(static_cast<int>( |
| (lo_space()->CommittedMemory() * 100.0) / CommittedMemory())); |
| |
| isolate_->counters()->heap_sample_total_committed()->AddSample( |
| static_cast<int>(CommittedMemory() / KB)); |
| isolate_->counters()->heap_sample_total_used()->AddSample( |
| static_cast<int>(SizeOfObjects() / KB)); |
| isolate_->counters()->heap_sample_map_space_committed()->AddSample( |
| static_cast<int>(map_space()->CommittedMemory() / KB)); |
| isolate_->counters()->heap_sample_code_space_committed()->AddSample( |
| static_cast<int>(code_space()->CommittedMemory() / KB)); |
| |
| isolate_->counters()->heap_sample_maximum_committed()->AddSample( |
| static_cast<int>(MaximumCommittedMemory() / KB)); |
| } |
| |
| #define UPDATE_COUNTERS_FOR_SPACE(space) \ |
| isolate_->counters()->space##_bytes_available()->Set( \ |
| static_cast<int>(space()->Available())); \ |
| isolate_->counters()->space##_bytes_committed()->Set( \ |
| static_cast<int>(space()->CommittedMemory())); \ |
| isolate_->counters()->space##_bytes_used()->Set( \ |
| static_cast<int>(space()->SizeOfObjects())); |
| #define UPDATE_FRAGMENTATION_FOR_SPACE(space) \ |
| if (space()->CommittedMemory() > 0) { \ |
| isolate_->counters()->external_fragmentation_##space()->AddSample( \ |
| static_cast<int>(100 - \ |
| (space()->SizeOfObjects() * 100.0) / \ |
| space()->CommittedMemory())); \ |
| } |
| #define UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(space) \ |
| UPDATE_COUNTERS_FOR_SPACE(space) \ |
| UPDATE_FRAGMENTATION_FOR_SPACE(space) |
| |
| UPDATE_COUNTERS_FOR_SPACE(new_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(old_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(code_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(map_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(lo_space) |
| #undef UPDATE_COUNTERS_FOR_SPACE |
| #undef UPDATE_FRAGMENTATION_FOR_SPACE |
| #undef UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE |
| |
| #ifdef DEBUG |
| ReportStatisticsAfterGC(); |
| #endif // DEBUG |
| |
| // Remember the last top pointer so that we can later find out |
| // whether we allocated in new space since the last GC. |
| new_space_top_after_last_gc_ = new_space()->top(); |
| last_gc_time_ = MonotonicallyIncreasingTimeInMs(); |
| |
| ReduceNewSpaceSize(); |
| } |
| |
| |
| void Heap::PreprocessStackTraces() { |
| WeakFixedArray::Iterator iterator(weak_stack_trace_list()); |
| FixedArray* elements; |
| while ((elements = iterator.Next<FixedArray>())) { |
| for (int j = 1; j < elements->length(); j += 4) { |
| Object* maybe_code = elements->get(j + 2); |
| // If GC happens while adding a stack trace to the weak fixed array, |
| // which has been copied into a larger backing store, we may run into |
| // a stack trace that has already been preprocessed. Guard against this. |
| if (!maybe_code->IsAbstractCode()) break; |
| AbstractCode* abstract_code = AbstractCode::cast(maybe_code); |
| int offset = Smi::cast(elements->get(j + 3))->value(); |
| int pos = abstract_code->SourcePosition(offset); |
| elements->set(j + 2, Smi::FromInt(pos)); |
| } |
| } |
| // We must not compact the weak fixed list here, as we may be in the middle |
| // of writing to it, when the GC triggered. Instead, we reset the root value. |
| set_weak_stack_trace_list(Smi::kZero); |
| } |
| |
| |
| class GCCallbacksScope { |
| public: |
| explicit GCCallbacksScope(Heap* heap) : heap_(heap) { |
| heap_->gc_callbacks_depth_++; |
| } |
| ~GCCallbacksScope() { heap_->gc_callbacks_depth_--; } |
| |
| bool CheckReenter() { return heap_->gc_callbacks_depth_ == 1; } |
| |
| private: |
| Heap* heap_; |
| }; |
| |
| |
| void Heap::HandleGCRequest() { |
| if (HighMemoryPressure()) { |
| incremental_marking()->reset_request_type(); |
| CheckMemoryPressure(); |
| } else if (incremental_marking()->request_type() == |
| IncrementalMarking::COMPLETE_MARKING) { |
| incremental_marking()->reset_request_type(); |
| CollectAllGarbage(current_gc_flags_, |
| GarbageCollectionReason::kFinalizeMarkingViaStackGuard, |
| current_gc_callback_flags_); |
| } else if (incremental_marking()->request_type() == |
| IncrementalMarking::FINALIZATION && |
| incremental_marking()->IsMarking() && |
| !incremental_marking()->finalize_marking_completed()) { |
| incremental_marking()->reset_request_type(); |
| FinalizeIncrementalMarking( |
| GarbageCollectionReason::kFinalizeMarkingViaStackGuard); |
| } |
| } |
| |
| |
| void Heap::ScheduleIdleScavengeIfNeeded(int bytes_allocated) { |
| scavenge_job_->ScheduleIdleTaskIfNeeded(this, bytes_allocated); |
| } |
| |
| void Heap::FinalizeIncrementalMarking(GarbageCollectionReason gc_reason) { |
| if (FLAG_trace_incremental_marking) { |
| isolate()->PrintWithTimestamp( |
| "[IncrementalMarking] (%s).\n", |
| Heap::GarbageCollectionReasonToString(gc_reason)); |
| } |
| |
| HistogramTimerScope incremental_marking_scope( |
| isolate()->counters()->gc_incremental_marking_finalize()); |
| TRACE_EVENT0("v8", "V8.GCIncrementalMarkingFinalize"); |
| TRACE_GC(tracer(), GCTracer::Scope::MC_INCREMENTAL_FINALIZE); |
| |
| { |
| GCCallbacksScope scope(this); |
| if (scope.CheckReenter()) { |
| AllowHeapAllocation allow_allocation; |
| TRACE_GC(tracer(), GCTracer::Scope::MC_INCREMENTAL_EXTERNAL_PROLOGUE); |
| VMState<EXTERNAL> state(isolate_); |
| HandleScope handle_scope(isolate_); |
| CallGCPrologueCallbacks(kGCTypeIncrementalMarking, kNoGCCallbackFlags); |
| } |
| } |
| incremental_marking()->FinalizeIncrementally(); |
| { |
| GCCallbacksScope scope(this); |
| if (scope.CheckReenter()) { |
| AllowHeapAllocation allow_allocation; |
| TRACE_GC(tracer(), GCTracer::Scope::MC_INCREMENTAL_EXTERNAL_EPILOGUE); |
| VMState<EXTERNAL> state(isolate_); |
| HandleScope handle_scope(isolate_); |
| CallGCEpilogueCallbacks(kGCTypeIncrementalMarking, kNoGCCallbackFlags); |
| } |
| } |
| } |
| |
| |
| HistogramTimer* Heap::GCTypeTimer(GarbageCollector collector) { |
| if (IsYoungGenerationCollector(collector)) { |
| return isolate_->counters()->gc_scavenger(); |
| } else { |
| if (!incremental_marking()->IsStopped()) { |
| if (ShouldReduceMemory()) { |
| return isolate_->counters()->gc_finalize_reduce_memory(); |
| } else { |
| return isolate_->counters()->gc_finalize(); |
| } |
| } else { |
| return isolate_->counters()->gc_compactor(); |
| } |
| } |
| } |
| |
| void Heap::CollectAllGarbage(int flags, GarbageCollectionReason gc_reason, |
| const v8::GCCallbackFlags gc_callback_flags) { |
| // Since we are ignoring the return value, the exact choice of space does |
| // not matter, so long as we do not specify NEW_SPACE, which would not |
| // cause a full GC. |
| set_current_gc_flags(flags); |
| CollectGarbage(OLD_SPACE, gc_reason, gc_callback_flags); |
| set_current_gc_flags(kNoGCFlags); |
| } |
| |
| void Heap::CollectAllAvailableGarbage(GarbageCollectionReason gc_reason) { |
| // Since we are ignoring the return value, the exact choice of space does |
| // not matter, so long as we do not specify NEW_SPACE, which would not |
| // cause a full GC. |
| // Major GC would invoke weak handle callbacks on weakly reachable |
| // handles, but won't collect weakly reachable objects until next |
| // major GC. Therefore if we collect aggressively and weak handle callback |
| // has been invoked, we rerun major GC to release objects which become |
| // garbage. |
| // Note: as weak callbacks can execute arbitrary code, we cannot |
| // hope that eventually there will be no weak callbacks invocations. |
| // Therefore stop recollecting after several attempts. |
| if (gc_reason == GarbageCollectionReason::kLastResort) { |
| InvokeOutOfMemoryCallback(); |
| } |
| RuntimeCallTimerScope(isolate(), &RuntimeCallStats::GC_AllAvailableGarbage); |
| if (isolate()->concurrent_recompilation_enabled()) { |
| // The optimizing compiler may be unnecessarily holding on to memory. |
| DisallowHeapAllocation no_recursive_gc; |
| isolate()->optimizing_compile_dispatcher()->Flush( |
| OptimizingCompileDispatcher::BlockingBehavior::kDontBlock); |
| } |
| isolate()->ClearSerializerData(); |
| set_current_gc_flags(kMakeHeapIterableMask | kReduceMemoryFootprintMask); |
| isolate_->compilation_cache()->Clear(); |
| const int kMaxNumberOfAttempts = 7; |
| const int kMinNumberOfAttempts = 2; |
| for (int attempt = 0; attempt < kMaxNumberOfAttempts; attempt++) { |
| if (!CollectGarbage(MARK_COMPACTOR, gc_reason, NULL, |
| v8::kGCCallbackFlagCollectAllAvailableGarbage) && |
| attempt + 1 >= kMinNumberOfAttempts) { |
| break; |
| } |
| } |
| set_current_gc_flags(kNoGCFlags); |
| new_space_->Shrink(); |
| UncommitFromSpace(); |
| } |
| |
| void Heap::ReportExternalMemoryPressure() { |
| if (external_memory_ > |
| (external_memory_at_last_mark_compact_ + external_memory_hard_limit())) { |
| CollectAllGarbage( |
| kReduceMemoryFootprintMask | kFinalizeIncrementalMarkingMask, |
| GarbageCollectionReason::kExternalMemoryPressure, |
| static_cast<GCCallbackFlags>(kGCCallbackFlagCollectAllAvailableGarbage | |
| kGCCallbackFlagCollectAllExternalMemory)); |
| return; |
| } |
| if (incremental_marking()->IsStopped()) { |
| if (incremental_marking()->CanBeActivated()) { |
| StartIncrementalMarking( |
| i::Heap::kNoGCFlags, GarbageCollectionReason::kExternalMemoryPressure, |
| static_cast<GCCallbackFlags>( |
| kGCCallbackFlagSynchronousPhantomCallbackProcessing | |
| kGCCallbackFlagCollectAllExternalMemory)); |
| } else { |
| CollectAllGarbage(i::Heap::kNoGCFlags, |
| GarbageCollectionReason::kExternalMemoryPressure, |
| kGCCallbackFlagSynchronousPhantomCallbackProcessing); |
| } |
| } else { |
| // Incremental marking is turned on an has already been started. |
| const double pressure = |
| static_cast<double>(external_memory_ - |
| external_memory_at_last_mark_compact_ - |
| kExternalAllocationSoftLimit) / |
| external_memory_hard_limit(); |
| DCHECK_GE(1, pressure); |
| const double kMaxStepSizeOnExternalLimit = 25; |
| const double deadline = MonotonicallyIncreasingTimeInMs() + |
| pressure * kMaxStepSizeOnExternalLimit; |
| incremental_marking()->AdvanceIncrementalMarking( |
| deadline, IncrementalMarking::GC_VIA_STACK_GUARD, |
| IncrementalMarking::FORCE_COMPLETION, StepOrigin::kV8); |
| } |
| } |
| |
| |
| void Heap::EnsureFillerObjectAtTop() { |
| // There may be an allocation memento behind objects in new space. Upon |
| // evacuation of a non-full new space (or if we are on the last page) there |
| // may be uninitialized memory behind top. We fill the remainder of the page |
| // with a filler. |
| Address to_top = new_space_->top(); |
| Page* page = Page::FromAddress(to_top - kPointerSize); |
| if (page->Contains(to_top)) { |
| int remaining_in_page = static_cast<int>(page->area_end() - to_top); |
| CreateFillerObjectAt(to_top, remaining_in_page, ClearRecordedSlots::kNo); |
| } |
| } |
| |
| bool Heap::CollectGarbage(GarbageCollector collector, |
| GarbageCollectionReason gc_reason, |
| const char* collector_reason, |
| const v8::GCCallbackFlags gc_callback_flags) { |
| // The VM is in the GC state until exiting this function. |
| VMState<GC> state(isolate_); |
| RuntimeCallTimerScope(isolate(), &RuntimeCallStats::GC); |
| |
| #ifdef DEBUG |
| // Reset the allocation timeout to the GC interval, but make sure to |
| // allow at least a few allocations after a collection. The reason |
| // for this is that we have a lot of allocation sequences and we |
| // assume that a garbage collection will allow the subsequent |
| // allocation attempts to go through. |
| allocation_timeout_ = Max(6, FLAG_gc_interval); |
| #endif |
| |
| EnsureFillerObjectAtTop(); |
| |
| if (IsYoungGenerationCollector(collector) && |
| !incremental_marking()->IsStopped()) { |
| if (FLAG_trace_incremental_marking) { |
| isolate()->PrintWithTimestamp( |
| "[IncrementalMarking] Scavenge during marking.\n"); |
| } |
| } |
| |
| if (collector == MARK_COMPACTOR && FLAG_incremental_marking && |
| !ShouldFinalizeIncrementalMarking() && !ShouldAbortIncrementalMarking() && |
| !incremental_marking()->IsStopped() && |
| !incremental_marking()->should_hurry() && |
| !incremental_marking()->NeedsFinalization() && |
| !IsCloseToOutOfMemory(new_space_->Capacity())) { |
| if (!incremental_marking()->IsComplete() && |
| !mark_compact_collector()->marking_deque()->IsEmpty() && |
| !FLAG_gc_global) { |
| if (FLAG_trace_incremental_marking) { |
| isolate()->PrintWithTimestamp( |
| "[IncrementalMarking] Delaying MarkSweep.\n"); |
| } |
| collector = YoungGenerationCollector(); |
| collector_reason = "incremental marking delaying mark-sweep"; |
| } |
| } |
| |
| bool next_gc_likely_to_collect_more = false; |
| size_t committed_memory_before = 0; |
| |
| if (collector == MARK_COMPACTOR) { |
| committed_memory_before = CommittedOldGenerationMemory(); |
| } |
| |
| { |
| tracer()->Start(collector, gc_reason, collector_reason); |
| DCHECK(AllowHeapAllocation::IsAllowed()); |
| DisallowHeapAllocation no_allocation_during_gc; |
| GarbageCollectionPrologue(); |
| |
| { |
| HistogramTimer* gc_type_timer = GCTypeTimer(collector); |
| HistogramTimerScope histogram_timer_scope(gc_type_timer); |
| TRACE_EVENT0("v8", gc_type_timer->name()); |
| |
| next_gc_likely_to_collect_more = |
| PerformGarbageCollection(collector, gc_callback_flags); |
| } |
| |
| GarbageCollectionEpilogue(); |
| if (collector == MARK_COMPACTOR && FLAG_track_detached_contexts) { |
| isolate()->CheckDetachedContextsAfterGC(); |
| } |
| |
| if (collector == MARK_COMPACTOR) { |
| size_t committed_memory_after = CommittedOldGenerationMemory(); |
| size_t used_memory_after = PromotedSpaceSizeOfObjects(); |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kMarkCompact; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| // Trigger one more GC if |
| // - this GC decreased committed memory, |
| // - there is high fragmentation, |
| // - there are live detached contexts. |
| event.next_gc_likely_to_collect_more = |
| (committed_memory_before > committed_memory_after + MB) || |
| HasHighFragmentation(used_memory_after, committed_memory_after) || |
| (detached_contexts()->length() > 0); |
| event.committed_memory = committed_memory_after; |
| if (deserialization_complete_) { |
| memory_reducer_->NotifyMarkCompact(event); |
| } |
| memory_pressure_level_.SetValue(MemoryPressureLevel::kNone); |
| } |
| |
| tracer()->Stop(collector); |
| } |
| |
| if (collector == MARK_COMPACTOR && |
| (gc_callback_flags & (kGCCallbackFlagForced | |
| kGCCallbackFlagCollectAllAvailableGarbage)) != 0) { |
| isolate()->CountUsage(v8::Isolate::kForcedGC); |
| } |
| |
| // Start incremental marking for the next cycle. The heap snapshot |
| // generator needs incremental marking to stay off after it aborted. |
| // We do this only for scavenger to avoid a loop where mark-compact |
| // causes another mark-compact. |
| if (IsYoungGenerationCollector(collector) && |
| !ShouldAbortIncrementalMarking()) { |
| StartIncrementalMarkingIfAllocationLimitIsReached(kNoGCFlags, |
| kNoGCCallbackFlags); |
| } |
| |
| return next_gc_likely_to_collect_more; |
| } |
| |
| |
| int Heap::NotifyContextDisposed(bool dependant_context) { |
| if (!dependant_context) { |
| tracer()->ResetSurvivalEvents(); |
| old_generation_size_configured_ = false; |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kPossibleGarbage; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| memory_reducer_->NotifyPossibleGarbage(event); |
| } |
| if (isolate()->concurrent_recompilation_enabled()) { |
| // Flush the queued recompilation tasks. |
| isolate()->optimizing_compile_dispatcher()->Flush( |
| OptimizingCompileDispatcher::BlockingBehavior::kDontBlock); |
| } |
| AgeInlineCaches(); |
| number_of_disposed_maps_ = retained_maps()->Length(); |
| tracer()->AddContextDisposalTime(MonotonicallyIncreasingTimeInMs()); |
| return ++contexts_disposed_; |
| } |
| |
| void Heap::StartIncrementalMarking(int gc_flags, |
| GarbageCollectionReason gc_reason, |
| GCCallbackFlags gc_callback_flags) { |
| DCHECK(incremental_marking()->IsStopped()); |
| set_current_gc_flags(gc_flags); |
| current_gc_callback_flags_ = gc_callback_flags; |
| incremental_marking()->Start(gc_reason); |
| } |
| |
| void Heap::StartIncrementalMarkingIfAllocationLimitIsReached( |
| int gc_flags, const GCCallbackFlags gc_callback_flags) { |
| if (incremental_marking()->IsStopped()) { |
| IncrementalMarkingLimit reached_limit = IncrementalMarkingLimitReached(); |
| if (reached_limit == IncrementalMarkingLimit::kSoftLimit) { |
| incremental_marking()->incremental_marking_job()->ScheduleTask(this); |
| } else if (reached_limit == IncrementalMarkingLimit::kHardLimit) { |
| StartIncrementalMarking(gc_flags, |
| GarbageCollectionReason::kAllocationLimit, |
| gc_callback_flags); |
| } |
| } |
| } |
| |
| void Heap::StartIdleIncrementalMarking(GarbageCollectionReason gc_reason) { |
| gc_idle_time_handler_->ResetNoProgressCounter(); |
| StartIncrementalMarking(kReduceMemoryFootprintMask, gc_reason, |
| kNoGCCallbackFlags); |
| } |
| |
| |
| void Heap::MoveElements(FixedArray* array, int dst_index, int src_index, |
| int len) { |
| if (len == 0) return; |
| |
| DCHECK(array->map() != fixed_cow_array_map()); |
| Object** dst_objects = array->data_start() + dst_index; |
| MemMove(dst_objects, array->data_start() + src_index, len * kPointerSize); |
| FIXED_ARRAY_ELEMENTS_WRITE_BARRIER(this, array, dst_index, len); |
| } |
| |
| |
| #ifdef VERIFY_HEAP |
| // Helper class for verifying the string table. |
| class StringTableVerifier : public ObjectVisitor { |
| public: |
| void VisitPointers(Object** start, Object** end) override { |
| // Visit all HeapObject pointers in [start, end). |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) { |
| HeapObject* object = HeapObject::cast(*p); |
| Isolate* isolate = object->GetIsolate(); |
| // Check that the string is actually internalized. |
| CHECK(object->IsTheHole(isolate) || object->IsUndefined(isolate) || |
| object->IsInternalizedString()); |
| } |
| } |
| } |
| }; |
| |
| |
| static void VerifyStringTable(Heap* heap) { |
| StringTableVerifier verifier; |
| heap->string_table()->IterateElements(&verifier); |
| } |
| #endif // VERIFY_HEAP |
| |
| bool Heap::ReserveSpace(Reservation* reservations, List<Address>* maps) { |
| bool gc_performed = true; |
| int counter = 0; |
| static const int kThreshold = 20; |
| while (gc_performed && counter++ < kThreshold) { |
| gc_performed = false; |
| for (int space = NEW_SPACE; space < SerializerDeserializer::kNumberOfSpaces; |
| space++) { |
| Reservation* reservation = &reservations[space]; |
| DCHECK_LE(1, reservation->length()); |
| if (reservation->at(0).size == 0) continue; |
| bool perform_gc = false; |
| if (space == MAP_SPACE) { |
| // We allocate each map individually to avoid fragmentation. |
| maps->Clear(); |
| DCHECK_EQ(1, reservation->length()); |
| int num_maps = reservation->at(0).size / Map::kSize; |
| for (int i = 0; i < num_maps; i++) { |
| // The deserializer will update the skip list. |
| AllocationResult allocation = map_space()->AllocateRawUnaligned( |
| Map::kSize, PagedSpace::IGNORE_SKIP_LIST); |
| HeapObject* free_space = nullptr; |
| if (allocation.To(&free_space)) { |
| // Mark with a free list node, in case we have a GC before |
| // deserializing. |
| Address free_space_address = free_space->address(); |
| CreateFillerObjectAt(free_space_address, Map::kSize, |
| ClearRecordedSlots::kNo); |
| maps->Add(free_space_address); |
| } else { |
| perform_gc = true; |
| break; |
| } |
| } |
| } else if (space == LO_SPACE) { |
| // Just check that we can allocate during deserialization. |
| DCHECK_EQ(1, reservation->length()); |
| perform_gc = !CanExpandOldGeneration(reservation->at(0).size); |
| } else { |
| for (auto& chunk : *reservation) { |
| AllocationResult allocation; |
| int size = chunk.size; |
| DCHECK_LE(static_cast<size_t>(size), |
| MemoryAllocator::PageAreaSize( |
| static_cast<AllocationSpace>(space))); |
| if (space == NEW_SPACE) { |
| allocation = new_space()->AllocateRawUnaligned(size); |
| } else { |
| // The deserializer will update the skip list. |
| allocation = paged_space(space)->AllocateRawUnaligned( |
| size, PagedSpace::IGNORE_SKIP_LIST); |
| } |
| HeapObject* free_space = nullptr; |
| if (allocation.To(&free_space)) { |
| // Mark with a free list node, in case we have a GC before |
| // deserializing. |
| Address free_space_address = free_space->address(); |
| CreateFillerObjectAt(free_space_address, size, |
| ClearRecordedSlots::kNo); |
| DCHECK(space < SerializerDeserializer::kNumberOfPreallocatedSpaces); |
| chunk.start = free_space_address; |
| chunk.end = free_space_address + size; |
| } else { |
| perform_gc = true; |
| break; |
| } |
| } |
| } |
| if (perform_gc) { |
| if (space == NEW_SPACE) { |
| CollectGarbage(NEW_SPACE, GarbageCollectionReason::kDeserializer); |
| } else { |
| if (counter > 1) { |
| CollectAllGarbage( |
| kReduceMemoryFootprintMask | kAbortIncrementalMarkingMask, |
| GarbageCollectionReason::kDeserializer); |
| } else { |
| CollectAllGarbage(kAbortIncrementalMarkingMask, |
| GarbageCollectionReason::kDeserializer); |
| } |
| } |
| gc_performed = true; |
| break; // Abort for-loop over spaces and retry. |
| } |
| } |
| } |
| |
| return !gc_performed; |
| } |
| |
| |
| void Heap::EnsureFromSpaceIsCommitted() { |
| if (new_space_->CommitFromSpaceIfNeeded()) return; |
| |
| // Committing memory to from space failed. |
| // Memory is exhausted and we will die. |
| V8::FatalProcessOutOfMemory("Committing semi space failed."); |
| } |
| |
| |
| void Heap::ClearNormalizedMapCaches() { |
| if (isolate_->bootstrapper()->IsActive() && |
| !incremental_marking()->IsMarking()) { |
| return; |
| } |
| |
| Object* context = native_contexts_list(); |
| while (!context->IsUndefined(isolate())) { |
| // GC can happen when the context is not fully initialized, |
| // so the cache can be undefined. |
| Object* cache = |
| Context::cast(context)->get(Context::NORMALIZED_MAP_CACHE_INDEX); |
| if (!cache->IsUndefined(isolate())) { |
| NormalizedMapCache::cast(cache)->Clear(); |
| } |
| context = Context::cast(context)->next_context_link(); |
| } |
| } |
| |
| |
| void Heap::UpdateSurvivalStatistics(int start_new_space_size) { |
| if (start_new_space_size == 0) return; |
| |
| promotion_ratio_ = (static_cast<double>(promoted_objects_size_) / |
| static_cast<double>(start_new_space_size) * 100); |
| |
| if (previous_semi_space_copied_object_size_ > 0) { |
| promotion_rate_ = |
| (static_cast<double>(promoted_objects_size_) / |
| static_cast<double>(previous_semi_space_copied_object_size_) * 100); |
| } else { |
| promotion_rate_ = 0; |
| } |
| |
| semi_space_copied_rate_ = |
| (static_cast<double>(semi_space_copied_object_size_) / |
| static_cast<double>(start_new_space_size) * 100); |
| |
| double survival_rate = promotion_ratio_ + semi_space_copied_rate_; |
| tracer()->AddSurvivalRatio(survival_rate); |
| } |
| |
| bool Heap::PerformGarbageCollection( |
| GarbageCollector collector, const v8::GCCallbackFlags gc_callback_flags) { |
| int freed_global_handles = 0; |
| |
| if (!IsYoungGenerationCollector(collector)) { |
| PROFILE(isolate_, CodeMovingGCEvent()); |
| } |
| |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| VerifyStringTable(this); |
| } |
| #endif |
| |
| GCType gc_type = |
| collector == MARK_COMPACTOR ? kGCTypeMarkSweepCompact : kGCTypeScavenge; |
| |
| { |
| GCCallbacksScope scope(this); |
| if (scope.CheckReenter()) { |
| AllowHeapAllocation allow_allocation; |
| TRACE_GC(tracer(), GCTracer::Scope::EXTERNAL_PROLOGUE); |
| VMState<EXTERNAL> state(isolate_); |
| HandleScope handle_scope(isolate_); |
| CallGCPrologueCallbacks(gc_type, kNoGCCallbackFlags); |
| } |
| } |
| |
| EnsureFromSpaceIsCommitted(); |
| |
| int start_new_space_size = static_cast<int>(Heap::new_space()->Size()); |
| |
| { |
| Heap::PretenuringScope pretenuring_scope(this); |
| Heap::SkipStoreBufferScope skip_store_buffer_scope(store_buffer_); |
| |
| switch (collector) { |
| case MARK_COMPACTOR: |
| UpdateOldGenerationAllocationCounter(); |
| // Perform mark-sweep with optional compaction. |
| MarkCompact(); |
| old_generation_size_configured_ = true; |
| // This should be updated before PostGarbageCollectionProcessing, which |
| // can cause another GC. Take into account the objects promoted during |
| // GC. |
| old_generation_allocation_counter_at_last_gc_ += |
| static_cast<size_t>(promoted_objects_size_); |
| old_generation_size_at_last_gc_ = PromotedSpaceSizeOfObjects(); |
| break; |
| case MINOR_MARK_COMPACTOR: |
| MinorMarkCompact(); |
| break; |
| case SCAVENGER: |
| Scavenge(); |
| break; |
| } |
| |
| ProcessPretenuringFeedback(); |
| } |
| |
| UpdateSurvivalStatistics(start_new_space_size); |
| ConfigureInitialOldGenerationSize(); |
| |
| isolate_->counters()->objs_since_last_young()->Set(0); |
| |
| gc_post_processing_depth_++; |
| { |
| AllowHeapAllocation allow_allocation; |
| TRACE_GC(tracer(), GCTracer::Scope::EXTERNAL_WEAK_GLOBAL_HANDLES); |
| freed_global_handles = |
| isolate_->global_handles()->PostGarbageCollectionProcessing( |
| collector, gc_callback_flags); |
| } |
| gc_post_processing_depth_--; |
| |
| isolate_->eternal_handles()->PostGarbageCollectionProcessing(this); |
| |
| // Update relocatables. |
| Relocatable::PostGarbageCollectionProcessing(isolate_); |
| |
| double gc_speed = tracer()->CombinedMarkCompactSpeedInBytesPerMillisecond(); |
| double mutator_speed = |
| tracer()->CurrentOldGenerationAllocationThroughputInBytesPerMillisecond(); |
| size_t old_gen_size = PromotedSpaceSizeOfObjects(); |
| if (collector == MARK_COMPACTOR) { |
| // Register the amount of external allocated memory. |
| external_memory_at_last_mark_compact_ = external_memory_; |
| external_memory_limit_ = external_memory_ + kExternalAllocationSoftLimit; |
| SetOldGenerationAllocationLimit(old_gen_size, gc_speed, mutator_speed); |
| } else if (HasLowYoungGenerationAllocationRate() && |
| old_generation_size_configured_) { |
| DampenOldGenerationAllocationLimit(old_gen_size, gc_speed, mutator_speed); |
| } |
| |
| { |
| GCCallbacksScope scope(this); |
| if (scope.CheckReenter()) { |
| AllowHeapAllocation allow_allocation; |
| TRACE_GC(tracer(), GCTracer::Scope::EXTERNAL_EPILOGUE); |
| VMState<EXTERNAL> state(isolate_); |
| HandleScope handle_scope(isolate_); |
| CallGCEpilogueCallbacks(gc_type, gc_callback_flags); |
| } |
| } |
| |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| VerifyStringTable(this); |
| } |
| #endif |
| |
| return freed_global_handles > 0; |
| } |
| |
| |
| void Heap::CallGCPrologueCallbacks(GCType gc_type, GCCallbackFlags flags) { |
| RuntimeCallTimerScope(isolate(), &RuntimeCallStats::GCPrologueCallback); |
| for (int i = 0; i < gc_prologue_callbacks_.length(); ++i) { |
| if (gc_type & gc_prologue_callbacks_[i].gc_type) { |
| if (!gc_prologue_callbacks_[i].pass_isolate) { |
| v8::GCCallback callback = reinterpret_cast<v8::GCCallback>( |
| gc_prologue_callbacks_[i].callback); |
| callback(gc_type, flags); |
| } else { |
| v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate()); |
| gc_prologue_callbacks_[i].callback(isolate, gc_type, flags); |
| } |
| } |
| } |
| if (FLAG_trace_object_groups && (gc_type == kGCTypeIncrementalMarking || |
| gc_type == kGCTypeMarkSweepCompact)) { |
| isolate_->global_handles()->PrintObjectGroups(); |
| } |
| } |
| |
| |
| void Heap::CallGCEpilogueCallbacks(GCType gc_type, |
| GCCallbackFlags gc_callback_flags) { |
| RuntimeCallTimerScope(isolate(), &RuntimeCallStats::GCEpilogueCallback); |
| for (int i = 0; i < gc_epilogue_callbacks_.length(); ++i) { |
| if (gc_type & gc_epilogue_callbacks_[i].gc_type) { |
| if (!gc_epilogue_callbacks_[i].pass_isolate) { |
| v8::GCCallback callback = reinterpret_cast<v8::GCCallback>( |
| gc_epilogue_callbacks_[i].callback); |
| callback(gc_type, gc_callback_flags); |
| } else { |
| v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate()); |
| gc_epilogue_callbacks_[i].callback(isolate, gc_type, gc_callback_flags); |
| } |
| } |
| } |
| } |
| |
| |
| void Heap::MarkCompact() { |
| PauseAllocationObserversScope pause_observers(this); |
| |
| SetGCState(MARK_COMPACT); |
| |
| LOG(isolate_, ResourceEvent("markcompact", "begin")); |
| |
| uint64_t size_of_objects_before_gc = SizeOfObjects(); |
| |
| mark_compact_collector()->Prepare(); |
| |
| ms_count_++; |
| |
| MarkCompactPrologue(); |
| |
| mark_compact_collector()->CollectGarbage(); |
| |
| LOG(isolate_, ResourceEvent("markcompact", "end")); |
| |
| MarkCompactEpilogue(); |
| |
| if (FLAG_allocation_site_pretenuring) { |
| EvaluateOldSpaceLocalPretenuring(size_of_objects_before_gc); |
| } |
| } |
| |
| void Heap::MinorMarkCompact() { UNREACHABLE(); } |
| |
| void Heap::MarkCompactEpilogue() { |
| TRACE_GC(tracer(), GCTracer::Scope::MC_EPILOGUE); |
| SetGCState(NOT_IN_GC); |
| |
| isolate_->counters()->objs_since_last_full()->Set(0); |
| |
| incremental_marking()->Epilogue(); |
| |
| PreprocessStackTraces(); |
| DCHECK(incremental_marking()->IsStopped()); |
| |
| mark_compact_collector()->marking_deque()->StopUsing(); |
| } |
| |
| |
| void Heap::MarkCompactPrologue() { |
| TRACE_GC(tracer(), GCTracer::Scope::MC_PROLOGUE); |
| isolate_->context_slot_cache()->Clear(); |
| isolate_->descriptor_lookup_cache()->Clear(); |
| RegExpResultsCache::Clear(string_split_cache()); |
| RegExpResultsCache::Clear(regexp_multiple_cache()); |
| |
| isolate_->compilation_cache()->MarkCompactPrologue(); |
| |
| CompletelyClearInstanceofCache(); |
| |
| FlushNumberStringCache(); |
| ClearNormalizedMapCaches(); |
| } |
| |
| |
| void Heap::CheckNewSpaceExpansionCriteria() { |
| if (FLAG_experimental_new_space_growth_heuristic) { |
| if (new_space_->TotalCapacity() < new_space_->MaximumCapacity() && |
| survived_last_scavenge_ * 100 / new_space_->TotalCapacity() >= 10) { |
| // Grow the size of new space if there is room to grow, and more than 10% |
| // have survived the last scavenge. |
| new_space_->Grow(); |
| survived_since_last_expansion_ = 0; |
| } |
| } else if (new_space_->TotalCapacity() < new_space_->MaximumCapacity() && |
| survived_since_last_expansion_ > new_space_->TotalCapacity()) { |
| // Grow the size of new space if there is room to grow, and enough data |
| // has survived scavenge since the last expansion. |
| new_space_->Grow(); |
| survived_since_last_expansion_ = 0; |
| } |
| } |
| |
| |
| static bool IsUnscavengedHeapObject(Heap* heap, Object** p) { |
| return heap->InNewSpace(*p) && |
| !HeapObject::cast(*p)->map_word().IsForwardingAddress(); |
| } |
| |
| void PromotionQueue::Initialize() { |
| // The last to-space page may be used for promotion queue. On promotion |
| // conflict, we use the emergency stack. |
| DCHECK((Page::kPageSize - MemoryChunk::kBodyOffset) % (2 * kPointerSize) == |
| 0); |
| front_ = rear_ = |
| reinterpret_cast<struct Entry*>(heap_->new_space()->ToSpaceEnd()); |
| limit_ = reinterpret_cast<struct Entry*>( |
| Page::FromAllocationAreaAddress(reinterpret_cast<Address>(rear_)) |
| ->area_start()); |
| emergency_stack_ = NULL; |
| } |
| |
| void PromotionQueue::Destroy() { |
| DCHECK(is_empty()); |
| delete emergency_stack_; |
| emergency_stack_ = NULL; |
| } |
| |
| void PromotionQueue::RelocateQueueHead() { |
| DCHECK(emergency_stack_ == NULL); |
| |
| Page* p = Page::FromAllocationAreaAddress(reinterpret_cast<Address>(rear_)); |
| struct Entry* head_start = rear_; |
| struct Entry* head_end = |
| Min(front_, reinterpret_cast<struct Entry*>(p->area_end())); |
| |
| int entries_count = |
| static_cast<int>(head_end - head_start) / sizeof(struct Entry); |
| |
| emergency_stack_ = new List<Entry>(2 * entries_count); |
| |
| while (head_start != head_end) { |
| struct Entry* entry = head_start++; |
| // New space allocation in SemiSpaceCopyObject marked the region |
| // overlapping with promotion queue as uninitialized. |
| MSAN_MEMORY_IS_INITIALIZED(entry, sizeof(struct Entry)); |
| emergency_stack_->Add(*entry); |
| } |
| rear_ = head_end; |
| } |
| |
| |
| class ScavengeWeakObjectRetainer : public WeakObjectRetainer { |
| public: |
| explicit ScavengeWeakObjectRetainer(Heap* heap) : heap_(heap) {} |
| |
| virtual Object* RetainAs(Object* object) { |
| if (!heap_->InFromSpace(object)) { |
| return object; |
| } |
| |
| MapWord map_word = HeapObject::cast(object)->map_word(); |
| if (map_word.IsForwardingAddress()) { |
| return map_word.ToForwardingAddress(); |
| } |
| return NULL; |
| } |
| |
| private: |
| Heap* heap_; |
| }; |
| |
| |
| void Heap::Scavenge() { |
| TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE); |
| RelocationLock relocation_lock(this); |
| // There are soft limits in the allocation code, designed to trigger a mark |
| // sweep collection by failing allocations. There is no sense in trying to |
| // trigger one during scavenge: scavenges allocation should always succeed. |
| AlwaysAllocateScope scope(isolate()); |
| |
| // Bump-pointer allocations done during scavenge are not real allocations. |
| // Pause the inline allocation steps. |
| PauseAllocationObserversScope pause_observers(this); |
| |
| mark_compact_collector()->sweeper().EnsureNewSpaceCompleted(); |
| |
| SetGCState(SCAVENGE); |
| |
| // Implements Cheney's copying algorithm |
| LOG(isolate_, ResourceEvent("scavenge", "begin")); |
| |
| // Used for updating survived_since_last_expansion_ at function end. |
| size_t survived_watermark = PromotedSpaceSizeOfObjects(); |
| |
| scavenge_collector_->SelectScavengingVisitorsTable(); |
| |
| // Flip the semispaces. After flipping, to space is empty, from space has |
| // live objects. |
| new_space_->Flip(); |
| new_space_->ResetAllocationInfo(); |
| |
| // We need to sweep newly copied objects which can be either in the |
| // to space or promoted to the old generation. For to-space |
| // objects, we treat the bottom of the to space as a queue. Newly |
| // copied and unswept objects lie between a 'front' mark and the |
| // allocation pointer. |
| // |
| // Promoted objects can go into various old-generation spaces, and |
| // can be allocated internally in the spaces (from the free list). |
| // We treat the top of the to space as a queue of addresses of |
| // promoted objects. The addresses of newly promoted and unswept |
| // objects lie between a 'front' mark and a 'rear' mark that is |
| // updated as a side effect of promoting an object. |
| // |
| // There is guaranteed to be enough room at the top of the to space |
| // for the addresses of promoted objects: every object promoted |
| // frees up its size in bytes from the top of the new space, and |
| // objects are at least one pointer in size. |
| Address new_space_front = new_space_->ToSpaceStart(); |
| promotion_queue_.Initialize(); |
| |
| ScavengeVisitor scavenge_visitor(this); |
| |
| isolate()->global_handles()->IdentifyWeakUnmodifiedObjects( |
| &IsUnmodifiedHeapObject); |
| |
| { |
| // Copy roots. |
| TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_ROOTS); |
| IterateRoots(&scavenge_visitor, VISIT_ALL_IN_SCAVENGE); |
| } |
| |
| { |
| // Copy objects reachable from the old generation. |
| TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_OLD_TO_NEW_POINTERS); |
| RememberedSet<OLD_TO_NEW>::Iterate(this, [this](Address addr) { |
| return Scavenger::CheckAndScavengeObject(this, addr); |
| }); |
| |
| RememberedSet<OLD_TO_NEW>::IterateTyped( |
| this, [this](SlotType type, Address host_addr, Address addr) { |
| return UpdateTypedSlotHelper::UpdateTypedSlot( |
| isolate(), type, addr, [this](Object** addr) { |
| // We expect that objects referenced by code are long living. |
| // If we do not force promotion, then we need to clear |
| // old_to_new slots in dead code objects after mark-compact. |
| return Scavenger::CheckAndScavengeObject( |
| this, reinterpret_cast<Address>(addr)); |
| }); |
| }); |
| } |
| |
| { |
| TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_WEAK); |
| // Copy objects reachable from the encountered weak collections list. |
| scavenge_visitor.VisitPointer(&encountered_weak_collections_); |
| } |
| |
| { |
| // Copy objects reachable from the code flushing candidates list. |
| TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_CODE_FLUSH_CANDIDATES); |
| MarkCompactCollector* collector = mark_compact_collector(); |
| if (collector->is_code_flushing_enabled()) { |
| collector->code_flusher()->IteratePointersToFromSpace(&scavenge_visitor); |
| } |
| } |
| |
| { |
| TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_SEMISPACE); |
| new_space_front = DoScavenge(&scavenge_visitor, new_space_front); |
| } |
| |
| isolate()->global_handles()->MarkNewSpaceWeakUnmodifiedObjectsPending( |
| &IsUnscavengedHeapObject); |
| |
| isolate() |
| ->global_handles() |
| ->IterateNewSpaceWeakUnmodifiedRoots< |
| GlobalHandles::HANDLE_PHANTOM_NODES_VISIT_OTHERS>(&scavenge_visitor); |
| new_space_front = DoScavenge(&scavenge_visitor, new_space_front); |
| |
| UpdateNewSpaceReferencesInExternalStringTable( |
| &UpdateNewSpaceReferenceInExternalStringTableEntry); |
| |
| promotion_queue_.Destroy(); |
| |
| incremental_marking()->UpdateMarkingDequeAfterScavenge(); |
| |
| ScavengeWeakObjectRetainer weak_object_retainer(this); |
| ProcessYoungWeakReferences(&weak_object_retainer); |
| |
| DCHECK(new_space_front == new_space_->top()); |
| |
| // Set age mark. |
| new_space_->set_age_mark(new_space_->top()); |
| |
| ArrayBufferTracker::FreeDeadInNewSpace(this); |
| |
| // Update how much has survived scavenge. |
| DCHECK_GE(PromotedSpaceSizeOfObjects(), survived_watermark); |
| IncrementYoungSurvivorsCounter(PromotedSpaceSizeOfObjects() + |
| new_space_->Size() - survived_watermark); |
| |
| // Scavenger may find new wrappers by iterating objects promoted onto a black |
| // page. |
| local_embedder_heap_tracer()->RegisterWrappersWithRemoteTracer(); |
| |
| LOG(isolate_, ResourceEvent("scavenge", "end")); |
| |
| SetGCState(NOT_IN_GC); |
| } |
| |
| |
| String* Heap::UpdateNewSpaceReferenceInExternalStringTableEntry(Heap* heap, |
| Object** p) { |
| MapWord first_word = HeapObject::cast(*p)->map_word(); |
| |
| if (!first_word.IsForwardingAddress()) { |
| // Unreachable external string can be finalized. |
| String* string = String::cast(*p); |
| if (!string->IsExternalString()) { |
| // Original external string has been internalized. |
| DCHECK(string->IsThinString()); |
| return NULL; |
| } |
| heap->FinalizeExternalString(string); |
| return NULL; |
| } |
| |
| // String is still reachable. |
| String* string = String::cast(first_word.ToForwardingAddress()); |
| if (string->IsThinString()) string = ThinString::cast(string)->actual(); |
| // Internalization can replace external strings with non-external strings. |
| return string->IsExternalString() ? string : nullptr; |
| } |
| |
| |
| void Heap::UpdateNewSpaceReferencesInExternalStringTable( |
| ExternalStringTableUpdaterCallback updater_func) { |
| if (external_string_table_.new_space_strings_.is_empty()) return; |
| |
| Object** start = &external_string_table_.new_space_strings_[0]; |
| Object** end = start + external_string_table_.new_space_strings_.length(); |
| Object** last = start; |
| |
| for (Object** p = start; p < end; ++p) { |
| String* target = updater_func(this, p); |
| |
| if (target == NULL) continue; |
| |
| DCHECK(target->IsExternalString()); |
| |
| if (InNewSpace(target)) { |
| // String is still in new space. Update the table entry. |
| *last = target; |
| ++last; |
| } else { |
| // String got promoted. Move it to the old string list. |
| external_string_table_.AddOldString(target); |
| } |
| } |
| |
| DCHECK(last <= end); |
| external_string_table_.ShrinkNewStrings(static_cast<int>(last - start)); |
| } |
| |
| |
| void Heap::UpdateReferencesInExternalStringTable( |
| ExternalStringTableUpdaterCallback updater_func) { |
| // Update old space string references. |
| if (external_string_table_.old_space_strings_.length() > 0) { |
| Object** start = &external_string_table_.old_space_strings_[0]; |
| Object** end = start + external_string_table_.old_space_strings_.length(); |
| for (Object** p = start; p < end; ++p) *p = updater_func(this, p); |
| } |
| |
| UpdateNewSpaceReferencesInExternalStringTable(updater_func); |
| } |
| |
| |
| void Heap::ProcessAllWeakReferences(WeakObjectRetainer* retainer) { |
| ProcessNativeContexts(retainer); |
| ProcessAllocationSites(retainer); |
| } |
| |
| |
| void Heap::ProcessYoungWeakReferences(WeakObjectRetainer* retainer) { |
| ProcessNativeContexts(retainer); |
| } |
| |
| |
| void Heap::ProcessNativeContexts(WeakObjectRetainer* retainer) { |
| Object* head = VisitWeakList<Context>(this, native_contexts_list(), retainer); |
| // Update the head of the list of contexts. |
| set_native_contexts_list(head); |
| } |
| |
| |
| void Heap::ProcessAllocationSites(WeakObjectRetainer* retainer) { |
| Object* allocation_site_obj = |
| VisitWeakList<AllocationSite>(this, allocation_sites_list(), retainer); |
| set_allocation_sites_list(allocation_site_obj); |
| } |
| |
| void Heap::ProcessWeakListRoots(WeakObjectRetainer* retainer) { |
| set_native_contexts_list(retainer->RetainAs(native_contexts_list())); |
| set_allocation_sites_list(retainer->RetainAs(allocation_sites_list())); |
| } |
| |
| void Heap::ResetAllAllocationSitesDependentCode(PretenureFlag flag) { |
| DisallowHeapAllocation no_allocation_scope; |
| Object* cur = allocation_sites_list(); |
| bool marked = false; |
| while (cur->IsAllocationSite()) { |
| AllocationSite* casted = AllocationSite::cast(cur); |
| if (casted->GetPretenureMode() == flag) { |
| casted->ResetPretenureDecision(); |
| casted->set_deopt_dependent_code(true); |
| marked = true; |
| RemoveAllocationSitePretenuringFeedback(casted); |
| } |
| cur = casted->weak_next(); |
| } |
| if (marked) isolate_->stack_guard()->RequestDeoptMarkedAllocationSites(); |
| } |
| |
| |
| void Heap::EvaluateOldSpaceLocalPretenuring( |
| uint64_t size_of_objects_before_gc) { |
| uint64_t size_of_objects_after_gc = SizeOfObjects(); |
| double old_generation_survival_rate = |
| (static_cast<double>(size_of_objects_after_gc) * 100) / |
| static_cast<double>(size_of_objects_before_gc); |
| |
| if (old_generation_survival_rate < kOldSurvivalRateLowThreshold) { |
| // Too many objects died in the old generation, pretenuring of wrong |
| // allocation sites may be the cause for that. We have to deopt all |
| // dependent code registered in the allocation sites to re-evaluate |
| // our pretenuring decisions. |
| ResetAllAllocationSitesDependentCode(TENURED); |
| if (FLAG_trace_pretenuring) { |
| PrintF( |
| "Deopt all allocation sites dependent code due to low survival " |
| "rate in the old generation %f\n", |
| old_generation_survival_rate); |
| } |
| } |
| } |
| |
| |
| void Heap::VisitExternalResources(v8::ExternalResourceVisitor* visitor) { |
| DisallowHeapAllocation no_allocation; |
| // All external strings are listed in the external string table. |
| |
| class ExternalStringTableVisitorAdapter : public ObjectVisitor { |
| public: |
| explicit ExternalStringTableVisitorAdapter( |
| v8::ExternalResourceVisitor* visitor) |
| : visitor_(visitor) {} |
| virtual void VisitPointers(Object** start, Object** end) { |
| for (Object** p = start; p < end; p++) { |
| DCHECK((*p)->IsExternalString()); |
| visitor_->VisitExternalString( |
| Utils::ToLocal(Handle<String>(String::cast(*p)))); |
| } |
| } |
| |
| private: |
| v8::ExternalResourceVisitor* visitor_; |
| } external_string_table_visitor(visitor); |
| |
| external_string_table_.IterateAll(&external_string_table_visitor); |
| } |
| |
| Address Heap::DoScavenge(ObjectVisitor* scavenge_visitor, |
| Address new_space_front) { |
| do { |
| SemiSpace::AssertValidRange(new_space_front, new_space_->top()); |
| // The addresses new_space_front and new_space_.top() define a |
| // queue of unprocessed copied objects. Process them until the |
| // queue is empty. |
| while (new_space_front != new_space_->top()) { |
| if (!Page::IsAlignedToPageSize(new_space_front)) { |
| HeapObject* object = HeapObject::FromAddress(new_space_front); |
| new_space_front += |
| StaticScavengeVisitor::IterateBody(object->map(), object); |
| } else { |
| new_space_front = Page::FromAllocationAreaAddress(new_space_front) |
| ->next_page() |
| ->area_start(); |
| } |
| } |
| |
| // Promote and process all the to-be-promoted objects. |
| { |
| while (!promotion_queue()->is_empty()) { |
| HeapObject* target; |
| int32_t size; |
| bool was_marked_black; |
| promotion_queue()->remove(&target, &size, &was_marked_black); |
| |
| // Promoted object might be already partially visited |
| // during old space pointer iteration. Thus we search specifically |
| // for pointers to from semispace instead of looking for pointers |
| // to new space. |
| DCHECK(!target->IsMap()); |
| |
| IterateAndScavengePromotedObject(target, static_cast<int>(size), |
| was_marked_black); |
| } |
| } |
| |
| // Take another spin if there are now unswept objects in new space |
| // (there are currently no more unswept promoted objects). |
| } while (new_space_front != new_space_->top()); |
| |
| return new_space_front; |
| } |
| |
| |
| STATIC_ASSERT((FixedDoubleArray::kHeaderSize & kDoubleAlignmentMask) == |
| 0); // NOLINT |
| STATIC_ASSERT((FixedTypedArrayBase::kDataOffset & kDoubleAlignmentMask) == |
| 0); // NOLINT |
| #ifdef V8_HOST_ARCH_32_BIT |
| STATIC_ASSERT((HeapNumber::kValueOffset & kDoubleAlignmentMask) != |
| 0); // NOLINT |
| #endif |
| |
| |
| int Heap::GetMaximumFillToAlign(AllocationAlignment alignment) { |
| switch (alignment) { |
| case kWordAligned: |
| return 0; |
| case kDoubleAligned: |
| case kDoubleUnaligned: |
| return kDoubleSize - kPointerSize; |
| case kSimd128Unaligned: |
| return kSimd128Size - kPointerSize; |
| default: |
| UNREACHABLE(); |
| } |
| return 0; |
| } |
| |
| |
| int Heap::GetFillToAlign(Address address, AllocationAlignment alignment) { |
| intptr_t offset = OffsetFrom(address); |
| if (alignment == kDoubleAligned && (offset & kDoubleAlignmentMask) != 0) |
| return kPointerSize; |
| if (alignment == kDoubleUnaligned && (offset & kDoubleAlignmentMask) == 0) |
| return kDoubleSize - kPointerSize; // No fill if double is always aligned. |
| if (alignment == kSimd128Unaligned) { |
| return (kSimd128Size - (static_cast<int>(offset) + kPointerSize)) & |
| kSimd128AlignmentMask; |
| } |
| return 0; |
| } |
| |
| |
| HeapObject* Heap::PrecedeWithFiller(HeapObject* object, int filler_size) { |
| CreateFillerObjectAt(object->address(), filler_size, ClearRecordedSlots::kNo); |
| return HeapObject::FromAddress(object->address() + filler_size); |
| } |
| |
| |
| HeapObject* Heap::AlignWithFiller(HeapObject* object, int object_size, |
| int allocation_size, |
| AllocationAlignment alignment) { |
| int filler_size = allocation_size - object_size; |
| DCHECK(filler_size > 0); |
| int pre_filler = GetFillToAlign(object->address(), alignment); |
| if (pre_filler) { |
| object = PrecedeWithFiller(object, pre_filler); |
| filler_size -= pre_filler; |
| } |
| if (filler_size) |
| CreateFillerObjectAt(object->address() + object_size, filler_size, |
| ClearRecordedSlots::kNo); |
| return object; |
| } |
| |
| |
| HeapObject* Heap::DoubleAlignForDeserialization(HeapObject* object, int size) { |
| return AlignWithFiller(object, size - kPointerSize, size, kDoubleAligned); |
| } |
| |
| |
| void Heap::RegisterNewArrayBuffer(JSArrayBuffer* buffer) { |
| ArrayBufferTracker::RegisterNew(this, buffer); |
| } |
| |
| |
| void Heap::UnregisterArrayBuffer(JSArrayBuffer* buffer) { |
| ArrayBufferTracker::Unregister(this, buffer); |
| } |
| |
| void Heap::ConfigureInitialOldGenerationSize() { |
| if (!old_generation_size_configured_ && tracer()->SurvivalEventsRecorded()) { |
| old_generation_allocation_limit_ = |
| Max(MinimumAllocationLimitGrowingStep(), |
| static_cast<size_t>( |
| static_cast<double>(old_generation_allocation_limit_) * |
| (tracer()->AverageSurvivalRatio() / 100))); |
| } |
| } |
| |
| AllocationResult Heap::AllocatePartialMap(InstanceType instance_type, |
| int instance_size) { |
| Object* result = nullptr; |
| AllocationResult allocation = AllocateRaw(Map::kSize, MAP_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| |
| // Map::cast cannot be used due to uninitialized map field. |
| reinterpret_cast<Map*>(result)->set_map( |
| reinterpret_cast<Map*>(root(kMetaMapRootIndex))); |
| reinterpret_cast<Map*>(result)->set_instance_type(instance_type); |
| reinterpret_cast<Map*>(result)->set_instance_size(instance_size); |
| // Initialize to only containing tagged fields. |
| reinterpret_cast<Map*>(result)->set_visitor_id( |
| StaticVisitorBase::GetVisitorId(instance_type, instance_size, false)); |
| if (FLAG_unbox_double_fields) { |
| reinterpret_cast<Map*>(result) |
| ->set_layout_descriptor(LayoutDescriptor::FastPointerLayout()); |
| } |
| reinterpret_cast<Map*>(result)->clear_unused(); |
| reinterpret_cast<Map*>(result) |
| ->set_inobject_properties_or_constructor_function_index(0); |
| reinterpret_cast<Map*>(result)->set_unused_property_fields(0); |
| reinterpret_cast<Map*>(result)->set_bit_field(0); |
| reinterpret_cast<Map*>(result)->set_bit_field2(0); |
| int bit_field3 = Map::EnumLengthBits::encode(kInvalidEnumCacheSentinel) | |
| Map::OwnsDescriptors::encode(true) | |
| Map::ConstructionCounter::encode(Map::kNoSlackTracking); |
| reinterpret_cast<Map*>(result)->set_bit_field3(bit_field3); |
| reinterpret_cast<Map*>(result)->set_weak_cell_cache(Smi::kZero); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateMap(InstanceType instance_type, |
| int instance_size, |
| ElementsKind elements_kind) { |
| HeapObject* result = nullptr; |
| AllocationResult allocation = AllocateRaw(Map::kSize, MAP_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| |
| isolate()->counters()->maps_created()->Increment(); |
| result->set_map_no_write_barrier(meta_map()); |
| Map* map = Map::cast(result); |
| map->set_instance_type(instance_type); |
| map->set_prototype(null_value(), SKIP_WRITE_BARRIER); |
| map->set_constructor_or_backpointer(null_value(), SKIP_WRITE_BARRIER); |
| map->set_instance_size(instance_size); |
| map->clear_unused(); |
| map->set_inobject_properties_or_constructor_function_index(0); |
| map->set_code_cache(empty_fixed_array(), SKIP_WRITE_BARRIER); |
| map->set_dependent_code(DependentCode::cast(empty_fixed_array()), |
| SKIP_WRITE_BARRIER); |
| map->set_weak_cell_cache(Smi::kZero); |
| map->set_raw_transitions(Smi::kZero); |
| map->set_unused_property_fields(0); |
| map->set_instance_descriptors(empty_descriptor_array()); |
| if (FLAG_unbox_double_fields) { |
| map->set_layout_descriptor(LayoutDescriptor::FastPointerLayout()); |
| } |
| // Must be called only after |instance_type|, |instance_size| and |
| // |layout_descriptor| are set. |
| map->set_visitor_id(Heap::GetStaticVisitorIdForMap(map)); |
| map->set_bit_field(0); |
| map->set_bit_field2(1 << Map::kIsExtensible); |
| int bit_field3 = Map::EnumLengthBits::encode(kInvalidEnumCacheSentinel) | |
| Map::OwnsDescriptors::encode(true) | |
| Map::ConstructionCounter::encode(Map::kNoSlackTracking); |
| map->set_bit_field3(bit_field3); |
| map->set_elements_kind(elements_kind); |
| map->set_new_target_is_base(true); |
| |
| return map; |
| } |
| |
| |
| AllocationResult Heap::AllocateFillerObject(int size, bool double_align, |
| AllocationSpace space) { |
| HeapObject* obj = nullptr; |
| { |
| AllocationAlignment align = double_align ? kDoubleAligned : kWordAligned; |
| AllocationResult allocation = AllocateRaw(size, space, align); |
| if (!allocation.To(&obj)) return allocation; |
| } |
| #ifdef DEBUG |
| MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address()); |
| DCHECK(chunk->owner()->identity() == space); |
| #endif |
| CreateFillerObjectAt(obj->address(), size, ClearRecordedSlots::kNo); |
| return obj; |
| } |
| |
| |
| const Heap::StringTypeTable Heap::string_type_table[] = { |
| #define STRING_TYPE_ELEMENT(type, size, name, camel_name) \ |
| { type, size, k##camel_name##MapRootIndex } \ |
| , |
| STRING_TYPE_LIST(STRING_TYPE_ELEMENT) |
| #undef STRING_TYPE_ELEMENT |
| }; |
| |
| |
| const Heap::ConstantStringTable Heap::constant_string_table[] = { |
| {"", kempty_stringRootIndex}, |
| #define CONSTANT_STRING_ELEMENT(name, contents) \ |
| { contents, k##name##RootIndex } \ |
| , |
| INTERNALIZED_STRING_LIST(CONSTANT_STRING_ELEMENT) |
| #undef CONSTANT_STRING_ELEMENT |
| }; |
| |
| |
| const Heap::StructTable Heap::struct_table[] = { |
| #define STRUCT_TABLE_ELEMENT(NAME, Name, name) \ |
| { NAME##_TYPE, Name::kSize, k##Name##MapRootIndex } \ |
| , |
| STRUCT_LIST(STRUCT_TABLE_ELEMENT) |
| #undef STRUCT_TABLE_ELEMENT |
| }; |
| |
| namespace { |
| |
| void FinalizePartialMap(Heap* heap, Map* map) { |
| map->set_code_cache(heap->empty_fixed_array()); |
| map->set_dependent_code(DependentCode::cast(heap->empty_fixed_array())); |
| map->set_raw_transitions(Smi::kZero); |
| map->set_instance_descriptors(heap->empty_descriptor_array()); |
| if (FLAG_unbox_double_fields) { |
| map->set_layout_descriptor(LayoutDescriptor::FastPointerLayout()); |
| } |
| map->set_prototype(heap->null_value()); |
| map->set_constructor_or_backpointer(heap->null_value()); |
| } |
| |
| } // namespace |
| |
| bool Heap::CreateInitialMaps() { |
| HeapObject* obj = nullptr; |
| { |
| AllocationResult allocation = AllocatePartialMap(MAP_TYPE, Map::kSize); |
| if (!allocation.To(&obj)) return false; |
| } |
| // Map::cast cannot be used due to uninitialized map field. |
| Map* new_meta_map = reinterpret_cast<Map*>(obj); |
| set_meta_map(new_meta_map); |
| new_meta_map->set_map(new_meta_map); |
| |
| { // Partial map allocation |
| #define ALLOCATE_PARTIAL_MAP(instance_type, size, field_name) \ |
| { \ |
| Map* map; \ |
| if (!AllocatePartialMap((instance_type), (size)).To(&map)) return false; \ |
| set_##field_name##_map(map); \ |
| } |
| |
| ALLOCATE_PARTIAL_MAP(FIXED_ARRAY_TYPE, kVariableSizeSentinel, fixed_array); |
| fixed_array_map()->set_elements_kind(FAST_HOLEY_ELEMENTS); |
| ALLOCATE_PARTIAL_MAP(ODDBALL_TYPE, Oddball::kSize, undefined); |
| ALLOCATE_PARTIAL_MAP(ODDBALL_TYPE, Oddball::kSize, null); |
| ALLOCATE_PARTIAL_MAP(ODDBALL_TYPE, Oddball::kSize, the_hole); |
| |
| #undef ALLOCATE_PARTIAL_MAP |
| } |
| |
| // Allocate the empty array. |
| { |
| AllocationResult allocation = AllocateEmptyFixedArray(); |
| if (!allocation.To(&obj)) return false; |
| } |
| set_empty_fixed_array(FixedArray::cast(obj)); |
| |
| { |
| AllocationResult allocation = Allocate(null_map(), OLD_SPACE); |
| if (!allocation.To(&obj)) return false; |
| } |
| set_null_value(Oddball::cast(obj)); |
| Oddball::cast(obj)->set_kind(Oddball::kNull); |
| |
| { |
| AllocationResult allocation = Allocate(undefined_map(), OLD_SPACE); |
| if (!allocation.To(&obj)) return false; |
| } |
| set_undefined_value(Oddball::cast(obj)); |
| Oddball::cast(obj)->set_kind(Oddball::kUndefined); |
| DCHECK(!InNewSpace(undefined_value())); |
| { |
| AllocationResult allocation = Allocate(the_hole_map(), OLD_SPACE); |
| if (!allocation.To(&obj)) return false; |
| } |
| set_the_hole_value(Oddball::cast(obj)); |
| Oddball::cast(obj)->set_kind(Oddball::kTheHole); |
| |
| // Set preliminary exception sentinel value before actually initializing it. |
| set_exception(null_value()); |
| |
| // Allocate the empty descriptor array. |
| { |
| AllocationResult allocation = AllocateEmptyFixedArray(); |
| if (!allocation.To(&obj)) return false; |
| } |
| set_empty_descriptor_array(DescriptorArray::cast(obj)); |
| |
| // Fix the instance_descriptors for the existing maps. |
| FinalizePartialMap(this, meta_map()); |
| FinalizePartialMap(this, fixed_array_map()); |
| FinalizePartialMap(this, undefined_map()); |
| undefined_map()->set_is_undetectable(); |
| FinalizePartialMap(this, null_map()); |
| null_map()->set_is_undetectable(); |
| FinalizePartialMap(this, the_hole_map()); |
| |
| { // Map allocation |
| #define ALLOCATE_MAP(instance_type, size, field_name) \ |
| { \ |
| Map* map; \ |
| if (!AllocateMap((instance_type), size).To(&map)) return false; \ |
| set_##field_name##_map(map); \ |
| } |
| |
| #define ALLOCATE_VARSIZE_MAP(instance_type, field_name) \ |
| ALLOCATE_MAP(instance_type, kVariableSizeSentinel, field_name) |
| |
| #define ALLOCATE_PRIMITIVE_MAP(instance_type, size, field_name, \ |
| constructor_function_index) \ |
| { \ |
| ALLOCATE_MAP((instance_type), (size), field_name); \ |
| field_name##_map()->SetConstructorFunctionIndex( \ |
| (constructor_function_index)); \ |
| } |
| |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, fixed_cow_array) |
| fixed_cow_array_map()->set_elements_kind(FAST_HOLEY_ELEMENTS); |
| DCHECK_NE(fixed_array_map(), fixed_cow_array_map()); |
| |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, scope_info) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, module_info) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, feedback_vector) |
| ALLOCATE_PRIMITIVE_MAP(HEAP_NUMBER_TYPE, HeapNumber::kSize, heap_number, |
| Context::NUMBER_FUNCTION_INDEX) |
| ALLOCATE_MAP(MUTABLE_HEAP_NUMBER_TYPE, HeapNumber::kSize, |
| mutable_heap_number) |
| ALLOCATE_PRIMITIVE_MAP(SYMBOL_TYPE, Symbol::kSize, symbol, |
| Context::SYMBOL_FUNCTION_INDEX) |
| ALLOCATE_MAP(FOREIGN_TYPE, Foreign::kSize, foreign) |
| |
| ALLOCATE_PRIMITIVE_MAP(ODDBALL_TYPE, Oddball::kSize, boolean, |
| Context::BOOLEAN_FUNCTION_INDEX); |
| ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, uninitialized); |
| ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, arguments_marker); |
| ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, no_interceptor_result_sentinel); |
| ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, exception); |
| ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, termination_exception); |
| ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, optimized_out); |
| ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, stale_register); |
| |
| ALLOCATE_MAP(JS_PROMISE_CAPABILITY_TYPE, JSPromiseCapability::kSize, |
| js_promise_capability); |
| |
| for (unsigned i = 0; i < arraysize(string_type_table); i++) { |
| const StringTypeTable& entry = string_type_table[i]; |
| { |
| AllocationResult allocation = AllocateMap(entry.type, entry.size); |
| if (!allocation.To(&obj)) return false; |
| } |
| Map* map = Map::cast(obj); |
| map->SetConstructorFunctionIndex(Context::STRING_FUNCTION_INDEX); |
| // Mark cons string maps as unstable, because their objects can change |
| // maps during GC. |
| if (StringShape(entry.type).IsCons()) map->mark_unstable(); |
| roots_[entry.index] = map; |
| } |
| |
| { // Create a separate external one byte string map for native sources. |
| AllocationResult allocation = |
| AllocateMap(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE, |
| ExternalOneByteString::kShortSize); |
| if (!allocation.To(&obj)) return false; |
| Map* map = Map::cast(obj); |
| map->SetConstructorFunctionIndex(Context::STRING_FUNCTION_INDEX); |
| set_native_source_string_map(map); |
| } |
| |
| ALLOCATE_VARSIZE_MAP(FIXED_DOUBLE_ARRAY_TYPE, fixed_double_array) |
| fixed_double_array_map()->set_elements_kind(FAST_HOLEY_DOUBLE_ELEMENTS); |
| ALLOCATE_VARSIZE_MAP(BYTE_ARRAY_TYPE, byte_array) |
| ALLOCATE_VARSIZE_MAP(BYTECODE_ARRAY_TYPE, bytecode_array) |
| ALLOCATE_VARSIZE_MAP(FREE_SPACE_TYPE, free_space) |
| |
| #define ALLOCATE_FIXED_TYPED_ARRAY_MAP(Type, type, TYPE, ctype, size) \ |
| ALLOCATE_VARSIZE_MAP(FIXED_##TYPE##_ARRAY_TYPE, fixed_##type##_array) |
| |
| TYPED_ARRAYS(ALLOCATE_FIXED_TYPED_ARRAY_MAP) |
| #undef ALLOCATE_FIXED_TYPED_ARRAY_MAP |
| |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, sloppy_arguments_elements) |
| |
| ALLOCATE_VARSIZE_MAP(CODE_TYPE, code) |
| |
| ALLOCATE_MAP(CELL_TYPE, Cell::kSize, cell) |
| ALLOCATE_MAP(PROPERTY_CELL_TYPE, PropertyCell::kSize, global_property_cell) |
| ALLOCATE_MAP(WEAK_CELL_TYPE, WeakCell::kSize, weak_cell) |
| ALLOCATE_MAP(CELL_TYPE, Cell::kSize, no_closures_cell) |
| ALLOCATE_MAP(CELL_TYPE, Cell::kSize, one_closure_cell) |
| ALLOCATE_MAP(CELL_TYPE, Cell::kSize, many_closures_cell) |
| ALLOCATE_MAP(FILLER_TYPE, kPointerSize, one_pointer_filler) |
| ALLOCATE_MAP(FILLER_TYPE, 2 * kPointerSize, two_pointer_filler) |
| |
| ALLOCATE_VARSIZE_MAP(TRANSITION_ARRAY_TYPE, transition_array) |
| |
| for (unsigned i = 0; i < arraysize(struct_table); i++) { |
| const StructTable& entry = struct_table[i]; |
| Map* map; |
| if (!AllocateMap(entry.type, entry.size).To(&map)) return false; |
| roots_[entry.index] = map; |
| } |
| |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, hash_table) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, ordered_hash_table) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, unseeded_number_dictionary) |
| |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, function_context) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, catch_context) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, with_context) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, debug_evaluate_context) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, block_context) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, module_context) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, eval_context) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, script_context) |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, script_context_table) |
| |
| ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, native_context) |
| native_context_map()->set_dictionary_map(true); |
| native_context_map()->set_visitor_id( |
| StaticVisitorBase::kVisitNativeContext); |
| |
| ALLOCATE_MAP(SHARED_FUNCTION_INFO_TYPE, SharedFunctionInfo::kAlignedSize, |
| shared_function_info) |
| |
| ALLOCATE_MAP(JS_MESSAGE_OBJECT_TYPE, JSMessageObject::kSize, message_object) |
| ALLOCATE_MAP(JS_OBJECT_TYPE, JSObject::kHeaderSize + kPointerSize, external) |
| external_map()->set_is_extensible(false); |
| #undef ALLOCATE_PRIMITIVE_MAP |
| #undef ALLOCATE_VARSIZE_MAP |
| #undef ALLOCATE_MAP |
| } |
| |
| { |
| AllocationResult allocation = AllocateEmptyScopeInfo(); |
| if (!allocation.To(&obj)) return false; |
| } |
| |
| set_empty_scope_info(ScopeInfo::cast(obj)); |
| { |
| AllocationResult allocation = Allocate(boolean_map(), OLD_SPACE); |
| if (!allocation.To(&obj)) return false; |
| } |
| set_true_value(Oddball::cast(obj)); |
| Oddball::cast(obj)->set_kind(Oddball::kTrue); |
| |
| { |
| AllocationResult allocation = Allocate(boolean_map(), OLD_SPACE); |
| if (!allocation.To(&obj)) return false; |
| } |
| set_false_value(Oddball::cast(obj)); |
| Oddball::cast(obj)->set_kind(Oddball::kFalse); |
| |
| { // Empty arrays |
| { |
| ByteArray* byte_array; |
| if (!AllocateByteArray(0, TENURED).To(&byte_array)) return false; |
| set_empty_byte_array(byte_array); |
| } |
| |
| #define ALLOCATE_EMPTY_FIXED_TYPED_ARRAY(Type, type, TYPE, ctype, size) \ |
| { \ |
| FixedTypedArrayBase* obj; \ |
| if (!AllocateEmptyFixedTypedArray(kExternal##Type##Array).To(&obj)) \ |
| return false; \ |
| set_empty_fixed_##type##_array(obj); \ |
| } |
| |
| TYPED_ARRAYS(ALLOCATE_EMPTY_FIXED_TYPED_ARRAY) |
| #undef ALLOCATE_EMPTY_FIXED_TYPED_ARRAY |
| } |
| DCHECK(!InNewSpace(empty_fixed_array())); |
| return true; |
| } |
| |
| AllocationResult Heap::AllocateHeapNumber(MutableMode mode, |
| PretenureFlag pretenure) { |
| // Statically ensure that it is safe to allocate heap numbers in paged |
| // spaces. |
| int size = HeapNumber::kSize; |
| STATIC_ASSERT(HeapNumber::kSize <= kMaxRegularHeapObjectSize); |
| |
| AllocationSpace space = SelectSpace(pretenure); |
| |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, space, kDoubleUnaligned); |
| if (!allocation.To(&result)) return allocation; |
| } |
| |
| Map* map = mode == MUTABLE ? mutable_heap_number_map() : heap_number_map(); |
| HeapObject::cast(result)->set_map_no_write_barrier(map); |
| return result; |
| } |
| |
| AllocationResult Heap::AllocateCell(Object* value) { |
| int size = Cell::kSize; |
| STATIC_ASSERT(Cell::kSize <= kMaxRegularHeapObjectSize); |
| |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| } |
| result->set_map_no_write_barrier(cell_map()); |
| Cell::cast(result)->set_value(value); |
| return result; |
| } |
| |
| AllocationResult Heap::AllocatePropertyCell() { |
| int size = PropertyCell::kSize; |
| STATIC_ASSERT(PropertyCell::kSize <= kMaxRegularHeapObjectSize); |
| |
| HeapObject* result = nullptr; |
| AllocationResult allocation = AllocateRaw(size, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| |
| result->set_map_no_write_barrier(global_property_cell_map()); |
| PropertyCell* cell = PropertyCell::cast(result); |
| cell->set_dependent_code(DependentCode::cast(empty_fixed_array()), |
| SKIP_WRITE_BARRIER); |
| cell->set_property_details(PropertyDetails(Smi::kZero)); |
| cell->set_value(the_hole_value()); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateWeakCell(HeapObject* value) { |
| int size = WeakCell::kSize; |
| STATIC_ASSERT(WeakCell::kSize <= kMaxRegularHeapObjectSize); |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| } |
| result->set_map_no_write_barrier(weak_cell_map()); |
| WeakCell::cast(result)->initialize(value); |
| WeakCell::cast(result)->clear_next(the_hole_value()); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateTransitionArray(int capacity) { |
| DCHECK(capacity > 0); |
| HeapObject* raw_array = nullptr; |
| { |
| AllocationResult allocation = AllocateRawFixedArray(capacity, TENURED); |
| if (!allocation.To(&raw_array)) return allocation; |
| } |
| raw_array->set_map_no_write_barrier(transition_array_map()); |
| TransitionArray* array = TransitionArray::cast(raw_array); |
| array->set_length(capacity); |
| MemsetPointer(array->data_start(), undefined_value(), capacity); |
| // Transition arrays are tenured. When black allocation is on we have to |
| // add the transition array to the list of encountered_transition_arrays. |
| if (incremental_marking()->black_allocation()) { |
| array->set_next_link(encountered_transition_arrays(), |
| UPDATE_WEAK_WRITE_BARRIER); |
| set_encountered_transition_arrays(array); |
| } else { |
| array->set_next_link(undefined_value(), SKIP_WRITE_BARRIER); |
| } |
| return array; |
| } |
| |
| bool Heap::CreateApiObjects() { |
| HandleScope scope(isolate()); |
| set_message_listeners(*TemplateList::New(isolate(), 2)); |
| HeapObject* obj = nullptr; |
| { |
| AllocationResult allocation = AllocateStruct(INTERCEPTOR_INFO_TYPE); |
| if (!allocation.To(&obj)) return false; |
| } |
| InterceptorInfo* info = InterceptorInfo::cast(obj); |
| info->set_flags(0); |
| set_noop_interceptor_info(info); |
| return true; |
| } |
| |
| |
| void Heap::CreateJSEntryStub() { |
| JSEntryStub stub(isolate(), StackFrame::ENTRY); |
| set_js_entry_code(*stub.GetCode()); |
| } |
| |
| |
| void Heap::CreateJSConstructEntryStub() { |
| JSEntryStub stub(isolate(), StackFrame::ENTRY_CONSTRUCT); |
| set_js_construct_entry_code(*stub.GetCode()); |
| } |
| |
| |
| void Heap::CreateFixedStubs() { |
| // Here we create roots for fixed stubs. They are needed at GC |
| // for cooking and uncooking (check out frames.cc). |
| // The eliminates the need for doing dictionary lookup in the |
| // stub cache for these stubs. |
| HandleScope scope(isolate()); |
| |
| // Create stubs that should be there, so we don't unexpectedly have to |
| // create them if we need them during the creation of another stub. |
| // Stub creation mixes raw pointers and handles in an unsafe manner so |
| // we cannot create stubs while we are creating stubs. |
| CodeStub::GenerateStubsAheadOfTime(isolate()); |
| |
| // MacroAssembler::Abort calls (usually enabled with --debug-code) depend on |
| // CEntryStub, so we need to call GenerateStubsAheadOfTime before JSEntryStub |
| // is created. |
| |
| // gcc-4.4 has problem generating correct code of following snippet: |
| // { JSEntryStub stub; |
| // js_entry_code_ = *stub.GetCode(); |
| // } |
| // { JSConstructEntryStub stub; |
| // js_construct_entry_code_ = *stub.GetCode(); |
| // } |
| // To workaround the problem, make separate functions without inlining. |
| Heap::CreateJSEntryStub(); |
| Heap::CreateJSConstructEntryStub(); |
| } |
| |
| |
| void Heap::CreateInitialObjects() { |
| HandleScope scope(isolate()); |
| Factory* factory = isolate()->factory(); |
| |
| // The -0 value must be set before NewNumber works. |
| set_minus_zero_value(*factory->NewHeapNumber(-0.0, IMMUTABLE, TENURED)); |
| DCHECK(std::signbit(minus_zero_value()->Number()) != 0); |
| |
| set_nan_value(*factory->NewHeapNumber( |
| std::numeric_limits<double>::quiet_NaN(), IMMUTABLE, TENURED)); |
| set_hole_nan_value( |
| *factory->NewHeapNumberFromBits(kHoleNanInt64, IMMUTABLE, TENURED)); |
| set_infinity_value(*factory->NewHeapNumber(V8_INFINITY, IMMUTABLE, TENURED)); |
| set_minus_infinity_value( |
| *factory->NewHeapNumber(-V8_INFINITY, IMMUTABLE, TENURED)); |
| |
| // Allocate initial string table. |
| set_string_table(*StringTable::New(isolate(), kInitialStringTableSize)); |
| |
| // Allocate |
| |
| // Finish initializing oddballs after creating the string table. |
| Oddball::Initialize(isolate(), factory->undefined_value(), "undefined", |
| factory->nan_value(), "undefined", Oddball::kUndefined); |
| |
| // Initialize the null_value. |
| Oddball::Initialize(isolate(), factory->null_value(), "null", |
| handle(Smi::kZero, isolate()), "object", Oddball::kNull); |
| |
| // Initialize the_hole_value. |
| Oddball::Initialize(isolate(), factory->the_hole_value(), "hole", |
| factory->hole_nan_value(), "undefined", |
| Oddball::kTheHole); |
| |
| // Initialize the true_value. |
| Oddball::Initialize(isolate(), factory->true_value(), "true", |
| handle(Smi::FromInt(1), isolate()), "boolean", |
| Oddball::kTrue); |
| |
| // Initialize the false_value. |
| Oddball::Initialize(isolate(), factory->false_value(), "false", |
| handle(Smi::kZero, isolate()), "boolean", |
| Oddball::kFalse); |
| |
| set_uninitialized_value( |
| *factory->NewOddball(factory->uninitialized_map(), "uninitialized", |
| handle(Smi::FromInt(-1), isolate()), "undefined", |
| Oddball::kUninitialized)); |
| |
| set_arguments_marker( |
| *factory->NewOddball(factory->arguments_marker_map(), "arguments_marker", |
| handle(Smi::FromInt(-4), isolate()), "undefined", |
| Oddball::kArgumentsMarker)); |
| |
| set_no_interceptor_result_sentinel(*factory->NewOddball( |
| factory->no_interceptor_result_sentinel_map(), |
| "no_interceptor_result_sentinel", handle(Smi::FromInt(-2), isolate()), |
| "undefined", Oddball::kOther)); |
| |
| set_termination_exception(*factory->NewOddball( |
| factory->termination_exception_map(), "termination_exception", |
| handle(Smi::FromInt(-3), isolate()), "undefined", Oddball::kOther)); |
| |
| set_exception(*factory->NewOddball(factory->exception_map(), "exception", |
| handle(Smi::FromInt(-5), isolate()), |
| "undefined", Oddball::kException)); |
| |
| set_optimized_out(*factory->NewOddball(factory->optimized_out_map(), |
| "optimized_out", |
| handle(Smi::FromInt(-6), isolate()), |
| "undefined", Oddball::kOptimizedOut)); |
| |
| set_stale_register( |
| *factory->NewOddball(factory->stale_register_map(), "stale_register", |
| handle(Smi::FromInt(-7), isolate()), "undefined", |
| Oddball::kStaleRegister)); |
| |
| for (unsigned i = 0; i < arraysize(constant_string_table); i++) { |
| Handle<String> str = |
| factory->InternalizeUtf8String(constant_string_table[i].contents); |
| roots_[constant_string_table[i].index] = *str; |
| } |
| |
| // Create the code_stubs dictionary. The initial size is set to avoid |
| // expanding the dictionary during bootstrapping. |
| set_code_stubs(*UnseededNumberDictionary::New(isolate(), 128)); |
| |
| set_instanceof_cache_function(Smi::kZero); |
| set_instanceof_cache_map(Smi::kZero); |
| set_instanceof_cache_answer(Smi::kZero); |
| |
| { |
| HandleScope scope(isolate()); |
| #define SYMBOL_INIT(name) \ |
| { \ |
| Handle<String> name##d = factory->NewStringFromStaticChars(#name); \ |
| Handle<Symbol> symbol(isolate()->factory()->NewPrivateSymbol()); \ |
| symbol->set_name(*name##d); \ |
| roots_[k##name##RootIndex] = *symbol; \ |
| } |
| PRIVATE_SYMBOL_LIST(SYMBOL_INIT) |
| #undef SYMBOL_INIT |
| } |
| |
| { |
| HandleScope scope(isolate()); |
| #define SYMBOL_INIT(name, description) \ |
| Handle<Symbol> name = factory->NewSymbol(); \ |
| Handle<String> name##d = factory->NewStringFromStaticChars(#description); \ |
| name->set_name(*name##d); \ |
| roots_[k##name##RootIndex] = *name; |
| PUBLIC_SYMBOL_LIST(SYMBOL_INIT) |
| #undef SYMBOL_INIT |
| |
| #define SYMBOL_INIT(name, description) \ |
| Handle<Symbol> name = factory->NewSymbol(); \ |
| Handle<String> name##d = factory->NewStringFromStaticChars(#description); \ |
| name->set_is_well_known_symbol(true); \ |
| name->set_name(*name##d); \ |
| roots_[k##name##RootIndex] = *name; |
| WELL_KNOWN_SYMBOL_LIST(SYMBOL_INIT) |
| #undef SYMBOL_INIT |
| } |
| |
| Handle<NameDictionary> empty_properties_dictionary = |
| NameDictionary::New(isolate(), 0, TENURED); |
| empty_properties_dictionary->SetRequiresCopyOnCapacityChange(); |
| set_empty_properties_dictionary(*empty_properties_dictionary); |
| |
| set_public_symbol_table(*empty_properties_dictionary); |
| set_api_symbol_table(*empty_properties_dictionary); |
| set_api_private_symbol_table(*empty_properties_dictionary); |
| |
| set_number_string_cache( |
| *factory->NewFixedArray(kInitialNumberStringCacheSize * 2, TENURED)); |
| |
| // Allocate cache for single character one byte strings. |
| set_single_character_string_cache( |
| *factory->NewFixedArray(String::kMaxOneByteCharCode + 1, TENURED)); |
| |
| // Allocate cache for string split and regexp-multiple. |
| set_string_split_cache(*factory->NewFixedArray( |
| RegExpResultsCache::kRegExpResultsCacheSize, TENURED)); |
| set_regexp_multiple_cache(*factory->NewFixedArray( |
| RegExpResultsCache::kRegExpResultsCacheSize, TENURED)); |
| |
| // Allocate cache for external strings pointing to native source code. |
| set_natives_source_cache( |
| *factory->NewFixedArray(Natives::GetBuiltinsCount())); |
| |
| set_experimental_natives_source_cache( |
| *factory->NewFixedArray(ExperimentalNatives::GetBuiltinsCount())); |
| |
| set_extra_natives_source_cache( |
| *factory->NewFixedArray(ExtraNatives::GetBuiltinsCount())); |
| |
| set_experimental_extra_natives_source_cache( |
| *factory->NewFixedArray(ExperimentalExtraNatives::GetBuiltinsCount())); |
| |
| set_undefined_cell(*factory->NewCell(factory->undefined_value())); |
| |
| // Microtask queue uses the empty fixed array as a sentinel for "empty". |
| // Number of queued microtasks stored in Isolate::pending_microtask_count(). |
| set_microtask_queue(empty_fixed_array()); |
| |
| { |
| Handle<FixedArray> empty_sloppy_arguments_elements = |
| factory->NewFixedArray(2, TENURED); |
| empty_sloppy_arguments_elements->set_map(sloppy_arguments_elements_map()); |
| set_empty_sloppy_arguments_elements(*empty_sloppy_arguments_elements); |
| } |
| |
| { |
| Handle<WeakCell> cell = factory->NewWeakCell(factory->undefined_value()); |
| set_empty_weak_cell(*cell); |
| cell->clear(); |
| } |
| |
| set_detached_contexts(empty_fixed_array()); |
| set_retained_maps(ArrayList::cast(empty_fixed_array())); |
| |
| set_weak_object_to_code_table( |
| *WeakHashTable::New(isolate(), 16, USE_DEFAULT_MINIMUM_CAPACITY, |
| TENURED)); |
| |
| set_weak_new_space_object_to_code_list( |
| ArrayList::cast(*(factory->NewFixedArray(16, TENURED)))); |
| weak_new_space_object_to_code_list()->SetLength(0); |
| |
| set_code_coverage_list(undefined_value()); |
| |
| set_script_list(Smi::kZero); |
| |
| Handle<SeededNumberDictionary> slow_element_dictionary = |
| SeededNumberDictionary::New(isolate(), 0, TENURED); |
| slow_element_dictionary->set_requires_slow_elements(); |
| set_empty_slow_element_dictionary(*slow_element_dictionary); |
| |
| set_materialized_objects(*factory->NewFixedArray(0, TENURED)); |
| |
| // Handling of script id generation is in Heap::NextScriptId(). |
| set_last_script_id(Smi::FromInt(v8::UnboundScript::kNoScriptId)); |
| set_next_template_serial_number(Smi::kZero); |
| |
| // Allocate the empty script. |
| Handle<Script> script = factory->NewScript(factory->empty_string()); |
| script->set_type(Script::TYPE_NATIVE); |
| set_empty_script(*script); |
| |
| Handle<PropertyCell> cell = factory->NewPropertyCell(); |
| cell->set_value(Smi::FromInt(Isolate::kProtectorValid)); |
| set_array_protector(*cell); |
| |
| cell = factory->NewPropertyCell(); |
| cell->set_value(the_hole_value()); |
| set_empty_property_cell(*cell); |
| |
| cell = factory->NewPropertyCell(); |
| cell->set_value(Smi::FromInt(Isolate::kProtectorValid)); |
| set_array_iterator_protector(*cell); |
| |
| Handle<Cell> is_concat_spreadable_cell = factory->NewCell( |
| handle(Smi::FromInt(Isolate::kProtectorValid), isolate())); |
| set_is_concat_spreadable_protector(*is_concat_spreadable_cell); |
| |
| Handle<Cell> species_cell = factory->NewCell( |
| handle(Smi::FromInt(Isolate::kProtectorValid), isolate())); |
| set_species_protector(*species_cell); |
| |
| cell = factory->NewPropertyCell(); |
| cell->set_value(Smi::FromInt(Isolate::kProtectorValid)); |
| set_string_length_protector(*cell); |
| |
| Handle<Cell> fast_array_iteration_cell = factory->NewCell( |
| handle(Smi::FromInt(Isolate::kProtectorValid), isolate())); |
| set_fast_array_iteration_protector(*fast_array_iteration_cell); |
| |
| cell = factory->NewPropertyCell(); |
| cell->set_value(Smi::FromInt(Isolate::kProtectorValid)); |
| set_array_buffer_neutering_protector(*cell); |
| |
| set_serialized_templates(empty_fixed_array()); |
| set_serialized_global_proxy_sizes(empty_fixed_array()); |
| |
| set_weak_stack_trace_list(Smi::kZero); |
| |
| set_noscript_shared_function_infos(Smi::kZero); |
| |
| // Initialize context slot cache. |
| isolate_->context_slot_cache()->Clear(); |
| |
| // Initialize descriptor cache. |
| isolate_->descriptor_lookup_cache()->Clear(); |
| |
| // Initialize compilation cache. |
| isolate_->compilation_cache()->Clear(); |
| |
| // Finish creating JSPromiseCapabilityMap |
| { |
| // TODO(caitp): This initialization can be removed once PromiseCapability |
| // object is no longer used by builtins implemented in javascript. |
| Handle<Map> map = factory->js_promise_capability_map(); |
| map->set_inobject_properties_or_constructor_function_index(3); |
| |
| Map::EnsureDescriptorSlack(map, 3); |
| |
| PropertyAttributes attrs = |
| static_cast<PropertyAttributes>(READ_ONLY | DONT_DELETE); |
| { // promise |
| Descriptor d = Descriptor::DataField(factory->promise_string(), |
| JSPromiseCapability::kPromiseIndex, |
| attrs, Representation::Tagged()); |
| map->AppendDescriptor(&d); |
| } |
| |
| { // resolve |
| Descriptor d = Descriptor::DataField(factory->resolve_string(), |
| JSPromiseCapability::kResolveIndex, |
| attrs, Representation::Tagged()); |
| map->AppendDescriptor(&d); |
| } |
| |
| { // reject |
| Descriptor d = Descriptor::DataField(factory->reject_string(), |
| JSPromiseCapability::kRejectIndex, |
| attrs, Representation::Tagged()); |
| map->AppendDescriptor(&d); |
| } |
| |
| map->set_is_extensible(false); |
| set_js_promise_capability_map(*map); |
| } |
| } |
| |
| bool Heap::RootCanBeWrittenAfterInitialization(Heap::RootListIndex root_index) { |
| switch (root_index) { |
| case kNumberStringCacheRootIndex: |
| case kInstanceofCacheFunctionRootIndex: |
| case kInstanceofCacheMapRootIndex: |
| case kInstanceofCacheAnswerRootIndex: |
| case kCodeStubsRootIndex: |
| case kEmptyScriptRootIndex: |
| case kScriptListRootIndex: |
| case kMaterializedObjectsRootIndex: |
| case kMicrotaskQueueRootIndex: |
| case kDetachedContextsRootIndex: |
| case kWeakObjectToCodeTableRootIndex: |
| case kWeakNewSpaceObjectToCodeListRootIndex: |
| case kRetainedMapsRootIndex: |
| case kCodeCoverageListRootIndex: |
| case kNoScriptSharedFunctionInfosRootIndex: |
| case kWeakStackTraceListRootIndex: |
| case kSerializedTemplatesRootIndex: |
| case kSerializedGlobalProxySizesRootIndex: |
| case kPublicSymbolTableRootIndex: |
| case kApiSymbolTableRootIndex: |
| case kApiPrivateSymbolTableRootIndex: |
| // Smi values |
| #define SMI_ENTRY(type, name, Name) case k##Name##RootIndex: |
| SMI_ROOT_LIST(SMI_ENTRY) |
| #undef SMI_ENTRY |
| // String table |
| case kStringTableRootIndex: |
| return true; |
| |
| default: |
| return false; |
| } |
| } |
| |
| bool Heap::RootCanBeTreatedAsConstant(RootListIndex root_index) { |
| return !RootCanBeWrittenAfterInitialization(root_index) && |
| !InNewSpace(root(root_index)); |
| } |
| |
| bool Heap::IsUnmodifiedHeapObject(Object** p) { |
| Object* object = *p; |
| if (object->IsSmi()) return false; |
| HeapObject* heap_object = HeapObject::cast(object); |
| if (!object->IsJSObject()) return false; |
| JSObject* js_object = JSObject::cast(object); |
| if (!js_object->WasConstructedFromApiFunction()) return false; |
| JSFunction* constructor = |
| JSFunction::cast(js_object->map()->GetConstructor()); |
| |
| return constructor->initial_map() == heap_object->map(); |
| } |
| |
| int Heap::FullSizeNumberStringCacheLength() { |
| // 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<size_t>(kInitialNumberStringCacheSize * 2), |
| Min<size_t>(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<int>(number_string_cache_size * 2); |
| } |
| |
| |
| void Heap::FlushNumberStringCache() { |
| // Flush the number to string cache. |
| int len = number_string_cache()->length(); |
| for (int i = 0; i < len; i++) { |
| number_string_cache()->set_undefined(i); |
| } |
| } |
| |
| |
| Map* Heap::MapForFixedTypedArray(ExternalArrayType array_type) { |
| return Map::cast(roots_[RootIndexForFixedTypedArray(array_type)]); |
| } |
| |
| |
| Heap::RootListIndex Heap::RootIndexForFixedTypedArray( |
| ExternalArrayType array_type) { |
| switch (array_type) { |
| #define ARRAY_TYPE_TO_ROOT_INDEX(Type, type, TYPE, ctype, size) \ |
| case kExternal##Type##Array: \ |
| return kFixed##Type##ArrayMapRootIndex; |
| |
| TYPED_ARRAYS(ARRAY_TYPE_TO_ROOT_INDEX) |
| #undef ARRAY_TYPE_TO_ROOT_INDEX |
| |
| default: |
| UNREACHABLE(); |
| return kUndefinedValueRootIndex; |
| } |
| } |
| |
| |
| Heap::RootListIndex Heap::RootIndexForEmptyFixedTypedArray( |
| ElementsKind elementsKind) { |
| switch (elementsKind) { |
| #define ELEMENT_KIND_TO_ROOT_INDEX(Type, type, TYPE, ctype, size) \ |
| case TYPE##_ELEMENTS: \ |
| return kEmptyFixed##Type##ArrayRootIndex; |
| |
| TYPED_ARRAYS(ELEMENT_KIND_TO_ROOT_INDEX) |
| #undef ELEMENT_KIND_TO_ROOT_INDEX |
| default: |
| UNREACHABLE(); |
| return kUndefinedValueRootIndex; |
| } |
| } |
| |
| |
| FixedTypedArrayBase* Heap::EmptyFixedTypedArrayForMap(Map* map) { |
| return FixedTypedArrayBase::cast( |
| roots_[RootIndexForEmptyFixedTypedArray(map->elements_kind())]); |
| } |
| |
| |
| AllocationResult Heap::AllocateForeign(Address address, |
| PretenureFlag pretenure) { |
| // Statically ensure that it is safe to allocate foreigns in paged spaces. |
| STATIC_ASSERT(Foreign::kSize <= kMaxRegularHeapObjectSize); |
| AllocationSpace space = (pretenure == TENURED) ? OLD_SPACE : NEW_SPACE; |
| Foreign* result = nullptr; |
| AllocationResult allocation = Allocate(foreign_map(), space); |
| if (!allocation.To(&result)) return allocation; |
| result->set_foreign_address(address); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateByteArray(int length, PretenureFlag pretenure) { |
| if (length < 0 || length > ByteArray::kMaxLength) { |
| v8::internal::Heap::FatalProcessOutOfMemory("invalid array length", true); |
| } |
| int size = ByteArray::SizeFor(length); |
| AllocationSpace space = SelectSpace(pretenure); |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, space); |
| if (!allocation.To(&result)) return allocation; |
| } |
| |
| result->set_map_no_write_barrier(byte_array_map()); |
| ByteArray::cast(result)->set_length(length); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateBytecodeArray(int length, |
| const byte* const raw_bytecodes, |
| int frame_size, |
| int parameter_count, |
| FixedArray* constant_pool) { |
| if (length < 0 || length > BytecodeArray::kMaxLength) { |
| v8::internal::Heap::FatalProcessOutOfMemory("invalid array length", true); |
| } |
| // Bytecode array is pretenured, so constant pool array should be to. |
| DCHECK(!InNewSpace(constant_pool)); |
| |
| int size = BytecodeArray::SizeFor(length); |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| } |
| |
| result->set_map_no_write_barrier(bytecode_array_map()); |
| BytecodeArray* instance = BytecodeArray::cast(result); |
| instance->set_length(length); |
| instance->set_frame_size(frame_size); |
| instance->set_parameter_count(parameter_count); |
| instance->set_interrupt_budget(interpreter::Interpreter::InterruptBudget()); |
| instance->set_osr_loop_nesting_level(0); |
| instance->set_bytecode_age(BytecodeArray::kNoAgeBytecodeAge); |
| instance->set_constant_pool(constant_pool); |
| instance->set_handler_table(empty_fixed_array()); |
| instance->set_source_position_table(empty_byte_array()); |
| CopyBytes(instance->GetFirstBytecodeAddress(), raw_bytecodes, length); |
| |
| return result; |
| } |
| |
| HeapObject* Heap::CreateFillerObjectAt(Address addr, int size, |
| ClearRecordedSlots mode) { |
| if (size == 0) return nullptr; |
| HeapObject* filler = HeapObject::FromAddress(addr); |
| if (size == kPointerSize) { |
| filler->set_map_no_write_barrier( |
| reinterpret_cast<Map*>(root(kOnePointerFillerMapRootIndex))); |
| } else if (size == 2 * kPointerSize) { |
| filler->set_map_no_write_barrier( |
| reinterpret_cast<Map*>(root(kTwoPointerFillerMapRootIndex))); |
| } else { |
| DCHECK_GT(size, 2 * kPointerSize); |
| filler->set_map_no_write_barrier( |
| reinterpret_cast<Map*>(root(kFreeSpaceMapRootIndex))); |
| FreeSpace::cast(filler)->nobarrier_set_size(size); |
| } |
| if (mode == ClearRecordedSlots::kYes) { |
| ClearRecordedSlotRange(addr, addr + size); |
| } |
| |
| // At this point, we may be deserializing the heap from a snapshot, and |
| // none of the maps have been created yet and are NULL. |
| DCHECK((filler->map() == NULL && !deserialization_complete_) || |
| filler->map()->IsMap()); |
| return filler; |
| } |
| |
| |
| bool Heap::CanMoveObjectStart(HeapObject* object) { |
| if (!FLAG_move_object_start) return false; |
| |
| // Sampling heap profiler may have a reference to the object. |
| if (isolate()->heap_profiler()->is_sampling_allocations()) return false; |
| |
| Address address = object->address(); |
| |
| if (lo_space()->Contains(object)) return false; |
| |
| // We can move the object start if the page was already swept. |
| return Page::FromAddress(address)->SweepingDone(); |
| } |
| |
| bool Heap::IsImmovable(HeapObject* object) { |
| MemoryChunk* chunk = MemoryChunk::FromAddress(object->address()); |
| return chunk->NeverEvacuate() || chunk->owner()->identity() == LO_SPACE; |
| } |
| |
| void Heap::AdjustLiveBytes(HeapObject* object, int by) { |
| // As long as the inspected object is black and we are currently not iterating |
| // the heap using HeapIterator, we can update the live byte count. We cannot |
| // update while using HeapIterator because the iterator is temporarily |
| // marking the whole object graph, without updating live bytes. |
| if (lo_space()->Contains(object)) { |
| lo_space()->AdjustLiveBytes(by); |
| } else if (!in_heap_iterator() && |
| !mark_compact_collector()->sweeping_in_progress() && |
| ObjectMarking::IsBlack(object)) { |
| DCHECK(MemoryChunk::FromAddress(object->address())->SweepingDone()); |
| MemoryChunk::IncrementLiveBytes(object, by); |
| } |
| } |
| |
| |
| FixedArrayBase* Heap::LeftTrimFixedArray(FixedArrayBase* object, |
| int elements_to_trim) { |
| CHECK_NOT_NULL(object); |
| DCHECK(CanMoveObjectStart(object)); |
| DCHECK(!object->IsFixedTypedArrayBase()); |
| DCHECK(!object->IsByteArray()); |
| const int element_size = object->IsFixedArray() ? kPointerSize : kDoubleSize; |
| const int bytes_to_trim = elements_to_trim * element_size; |
| Map* map = object->map(); |
| |
| // For now this trick is only applied to objects in new and paged space. |
| // In large object space the object's start must coincide with chunk |
| // and thus the trick is just not applicable. |
| DCHECK(!lo_space()->Contains(object)); |
| DCHECK(object->map() != fixed_cow_array_map()); |
| |
| STATIC_ASSERT(FixedArrayBase::kMapOffset == 0); |
| STATIC_ASSERT(FixedArrayBase::kLengthOffset == kPointerSize); |
| STATIC_ASSERT(FixedArrayBase::kHeaderSize == 2 * kPointerSize); |
| |
| const int len = object->length(); |
| DCHECK(elements_to_trim <= len); |
| |
| // Calculate location of new array start. |
| Address old_start = object->address(); |
| Address new_start = old_start + bytes_to_trim; |
| |
| // Transfer the mark bits to their new location if the object is not within |
| // a black area. |
| if (!incremental_marking()->black_allocation() || |
| !Marking::IsBlack( |
| ObjectMarking::MarkBitFrom(HeapObject::FromAddress(new_start)))) { |
| IncrementalMarking::TransferMark(this, object, |
| HeapObject::FromAddress(new_start)); |
| } |
| |
| // Technically in new space this write might be omitted (except for |
| // debug mode which iterates through the heap), but to play safer |
| // we still do it. |
| CreateFillerObjectAt(old_start, bytes_to_trim, ClearRecordedSlots::kYes); |
| |
| // Clear the mark bits of the black area that belongs now to the filler. |
| // This is an optimization. The sweeper will release black fillers anyway. |
| if (incremental_marking()->black_allocation() && |
| Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(object))) { |
| Page* page = Page::FromAddress(old_start); |
| page->markbits()->ClearRange( |
| page->AddressToMarkbitIndex(old_start), |
| page->AddressToMarkbitIndex(old_start + bytes_to_trim)); |
| } |
| |
| // Initialize header of the trimmed array. Since left trimming is only |
| // performed on pages which are not concurrently swept creating a filler |
| // object does not require synchronization. |
| Object** former_start = HeapObject::RawField(object, 0); |
| int new_start_index = elements_to_trim * (element_size / kPointerSize); |
| former_start[new_start_index] = map; |
| former_start[new_start_index + 1] = Smi::FromInt(len - elements_to_trim); |
| |
| FixedArrayBase* new_object = |
| FixedArrayBase::cast(HeapObject::FromAddress(new_start)); |
| |
| // Maintain consistency of live bytes during incremental marking |
| AdjustLiveBytes(new_object, -bytes_to_trim); |
| |
| // Remove recorded slots for the new map and length offset. |
| ClearRecordedSlot(new_object, HeapObject::RawField(new_object, 0)); |
| ClearRecordedSlot(new_object, HeapObject::RawField( |
| new_object, FixedArrayBase::kLengthOffset)); |
| |
| // Notify the heap profiler of change in object layout. |
| OnMoveEvent(new_object, object, new_object->Size()); |
| return new_object; |
| } |
| |
| void Heap::RightTrimFixedArray(FixedArrayBase* object, int elements_to_trim) { |
| const int len = object->length(); |
| DCHECK_LE(elements_to_trim, len); |
| DCHECK_GE(elements_to_trim, 0); |
| |
| int bytes_to_trim; |
| if (object->IsFixedTypedArrayBase()) { |
| InstanceType type = object->map()->instance_type(); |
| bytes_to_trim = |
| FixedTypedArrayBase::TypedArraySize(type, len) - |
| FixedTypedArrayBase::TypedArraySize(type, len - elements_to_trim); |
| } else if (object->IsByteArray()) { |
| int new_size = ByteArray::SizeFor(len - elements_to_trim); |
| bytes_to_trim = ByteArray::SizeFor(len) - new_size; |
| DCHECK_GE(bytes_to_trim, 0); |
| } else { |
| const int element_size = |
| object->IsFixedArray() ? kPointerSize : kDoubleSize; |
| bytes_to_trim = elements_to_trim * element_size; |
| } |
| |
| |
| // For now this trick is only applied to objects in new and paged space. |
| DCHECK(object->map() != fixed_cow_array_map()); |
| |
| if (bytes_to_trim == 0) { |
| // No need to create filler and update live bytes counters, just initialize |
| // header of the trimmed array. |
| object->synchronized_set_length(len - elements_to_trim); |
| return; |
| } |
| |
| // Calculate location of new array end. |
| Address old_end = object->address() + object->Size(); |
| Address new_end = old_end - bytes_to_trim; |
| |
| // Technically in new space this write might be omitted (except for |
| // debug mode which iterates through the heap), but to play safer |
| // we still do it. |
| // We do not create a filler for objects in large object space. |
| // TODO(hpayer): We should shrink the large object page if the size |
| // of the object changed significantly. |
| if (!lo_space()->Contains(object)) { |
| HeapObject* filler = |
| CreateFillerObjectAt(new_end, bytes_to_trim, ClearRecordedSlots::kYes); |
| DCHECK_NOT_NULL(filler); |
| // Clear the mark bits of the black area that belongs now to the filler. |
| // This is an optimization. The sweeper will release black fillers anyway. |
| if (incremental_marking()->black_allocation() && |
| ObjectMarking::IsBlackOrGrey(filler)) { |
| Page* page = Page::FromAddress(new_end); |
| page->markbits()->ClearRange( |
| page->AddressToMarkbitIndex(new_end), |
| page->AddressToMarkbitIndex(new_end + bytes_to_trim)); |
| } |
| } |
| |
| // Initialize header of the trimmed array. We are storing the new length |
| // using release store after creating a filler for the left-over space to |
| // avoid races with the sweeper thread. |
| object->synchronized_set_length(len - elements_to_trim); |
| |
| // Maintain consistency of live bytes during incremental marking |
| AdjustLiveBytes(object, -bytes_to_trim); |
| |
| // Notify the heap profiler of change in object layout. The array may not be |
| // moved during GC, and size has to be adjusted nevertheless. |
| HeapProfiler* profiler = isolate()->heap_profiler(); |
| if (profiler->is_tracking_allocations()) { |
| profiler->UpdateObjectSizeEvent(object->address(), object->Size()); |
| } |
| } |
| |
| |
| AllocationResult Heap::AllocateFixedTypedArrayWithExternalPointer( |
| int length, ExternalArrayType array_type, void* external_pointer, |
| PretenureFlag pretenure) { |
| int size = FixedTypedArrayBase::kHeaderSize; |
| AllocationSpace space = SelectSpace(pretenure); |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, space); |
| if (!allocation.To(&result)) return allocation; |
| } |
| |
| result->set_map_no_write_barrier(MapForFixedTypedArray(array_type)); |
| FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(result); |
| elements->set_base_pointer(Smi::kZero, SKIP_WRITE_BARRIER); |
| elements->set_external_pointer(external_pointer, SKIP_WRITE_BARRIER); |
| elements->set_length(length); |
| return elements; |
| } |
| |
| static void ForFixedTypedArray(ExternalArrayType array_type, int* element_size, |
| ElementsKind* element_kind) { |
| switch (array_type) { |
| #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \ |
| case kExternal##Type##Array: \ |
| *element_size = size; \ |
| *element_kind = TYPE##_ELEMENTS; \ |
| return; |
| |
| TYPED_ARRAYS(TYPED_ARRAY_CASE) |
| #undef TYPED_ARRAY_CASE |
| |
| default: |
| *element_size = 0; // Bogus |
| *element_kind = UINT8_ELEMENTS; // Bogus |
| UNREACHABLE(); |
| } |
| } |
| |
| |
| AllocationResult Heap::AllocateFixedTypedArray(int length, |
| ExternalArrayType array_type, |
| bool initialize, |
| PretenureFlag pretenure) { |
| int element_size; |
| ElementsKind elements_kind; |
| ForFixedTypedArray(array_type, &element_size, &elements_kind); |
| int size = OBJECT_POINTER_ALIGN(length * element_size + |
| FixedTypedArrayBase::kDataOffset); |
| AllocationSpace space = SelectSpace(pretenure); |
| |
| HeapObject* object = nullptr; |
| AllocationResult allocation = AllocateRaw( |
| size, space, |
| array_type == kExternalFloat64Array ? kDoubleAligned : kWordAligned); |
| if (!allocation.To(&object)) return allocation; |
| |
| object->set_map_no_write_barrier(MapForFixedTypedArray(array_type)); |
| FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(object); |
| elements->set_base_pointer(elements, SKIP_WRITE_BARRIER); |
| elements->set_external_pointer( |
| ExternalReference::fixed_typed_array_base_data_offset().address(), |
| SKIP_WRITE_BARRIER); |
| elements->set_length(length); |
| if (initialize) memset(elements->DataPtr(), 0, elements->DataSize()); |
| return elements; |
| } |
| |
| |
| AllocationResult Heap::AllocateCode(int object_size, bool immovable) { |
| DCHECK(IsAligned(static_cast<intptr_t>(object_size), kCodeAlignment)); |
| AllocationResult allocation = AllocateRaw(object_size, CODE_SPACE); |
| |
| HeapObject* result = nullptr; |
| if (!allocation.To(&result)) return allocation; |
| if (immovable) { |
| Address address = result->address(); |
| MemoryChunk* chunk = MemoryChunk::FromAddress(address); |
| // Code objects which should stay at a fixed address are allocated either |
| // in the first page of code space (objects on the first page of each space |
| // are never moved), in large object space, or (during snapshot creation) |
| // the containing page is marked as immovable. |
| if (!Heap::IsImmovable(result) && |
| !code_space_->FirstPage()->Contains(address)) { |
| if (isolate()->serializer_enabled()) { |
| chunk->MarkNeverEvacuate(); |
| } else { |
| // Discard the first code allocation, which was on a page where it could |
| // be moved. |
| CreateFillerObjectAt(result->address(), object_size, |
| ClearRecordedSlots::kNo); |
| allocation = lo_space_->AllocateRaw(object_size, EXECUTABLE); |
| if (!allocation.To(&result)) return allocation; |
| OnAllocationEvent(result, object_size); |
| } |
| } |
| } |
| |
| result->set_map_no_write_barrier(code_map()); |
| Code* code = Code::cast(result); |
| DCHECK(IsAligned(bit_cast<intptr_t>(code->address()), kCodeAlignment)); |
| DCHECK(!memory_allocator()->code_range()->valid() || |
| memory_allocator()->code_range()->contains(code->address()) || |
| object_size <= code_space()->AreaSize()); |
| code->set_gc_metadata(Smi::kZero); |
| code->set_ic_age(global_ic_age_); |
| return code; |
| } |
| |
| |
| AllocationResult Heap::CopyCode(Code* code) { |
| AllocationResult allocation; |
| |
| HeapObject* result = nullptr; |
| // Allocate an object the same size as the code object. |
| int obj_size = code->Size(); |
| allocation = AllocateRaw(obj_size, CODE_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| |
| // Copy code object. |
| Address old_addr = code->address(); |
| Address new_addr = result->address(); |
| CopyBlock(new_addr, old_addr, obj_size); |
| Code* new_code = Code::cast(result); |
| |
| // Relocate the copy. |
| DCHECK(IsAligned(bit_cast<intptr_t>(new_code->address()), kCodeAlignment)); |
| DCHECK(!memory_allocator()->code_range()->valid() || |
| memory_allocator()->code_range()->contains(code->address()) || |
| obj_size <= code_space()->AreaSize()); |
| new_code->Relocate(new_addr - old_addr); |
| // We have to iterate over the object and process its pointers when black |
| // allocation is on. |
| incremental_marking()->IterateBlackObject(new_code); |
| // Record all references to embedded objects in the new code object. |
| RecordWritesIntoCode(new_code); |
| return new_code; |
| } |
| |
| AllocationResult Heap::CopyBytecodeArray(BytecodeArray* bytecode_array) { |
| int size = BytecodeArray::SizeFor(bytecode_array->length()); |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| } |
| |
| result->set_map_no_write_barrier(bytecode_array_map()); |
| BytecodeArray* copy = BytecodeArray::cast(result); |
| copy->set_length(bytecode_array->length()); |
| copy->set_frame_size(bytecode_array->frame_size()); |
| copy->set_parameter_count(bytecode_array->parameter_count()); |
| copy->set_constant_pool(bytecode_array->constant_pool()); |
| copy->set_handler_table(bytecode_array->handler_table()); |
| copy->set_source_position_table(bytecode_array->source_position_table()); |
| copy->set_interrupt_budget(bytecode_array->interrupt_budget()); |
| copy->set_osr_loop_nesting_level(bytecode_array->osr_loop_nesting_level()); |
| copy->set_bytecode_age(bytecode_array->bytecode_age()); |
| bytecode_array->CopyBytecodesTo(copy); |
| return copy; |
| } |
| |
| void Heap::InitializeAllocationMemento(AllocationMemento* memento, |
| AllocationSite* allocation_site) { |
| memento->set_map_no_write_barrier(allocation_memento_map()); |
| DCHECK(allocation_site->map() == allocation_site_map()); |
| memento->set_allocation_site(allocation_site, SKIP_WRITE_BARRIER); |
| if (FLAG_allocation_site_pretenuring) { |
| allocation_site->IncrementMementoCreateCount(); |
| } |
| } |
| |
| |
| AllocationResult Heap::Allocate(Map* map, AllocationSpace space, |
| AllocationSite* allocation_site) { |
| DCHECK(gc_state_ == NOT_IN_GC); |
| DCHECK(map->instance_type() != MAP_TYPE); |
| int size = map->instance_size(); |
| if (allocation_site != NULL) { |
| size += AllocationMemento::kSize; |
| } |
| HeapObject* result = nullptr; |
| AllocationResult allocation = AllocateRaw(size, space); |
| if (!allocation.To(&result)) return allocation; |
| // No need for write barrier since object is white and map is in old space. |
| result->set_map_no_write_barrier(map); |
| if (allocation_site != NULL) { |
| AllocationMemento* alloc_memento = reinterpret_cast<AllocationMemento*>( |
| reinterpret_cast<Address>(result) + map->instance_size()); |
| InitializeAllocationMemento(alloc_memento, allocation_site); |
| } |
| return result; |
| } |
| |
| |
| void Heap::InitializeJSObjectFromMap(JSObject* obj, FixedArray* properties, |
| Map* map) { |
| obj->set_properties(properties); |
| obj->initialize_elements(); |
| // TODO(1240798): Initialize the object's body using valid initial values |
| // according to the object's initial map. For example, if the map's |
| // instance type is JS_ARRAY_TYPE, the length field should be initialized |
| // to a number (e.g. Smi::kZero) and the elements initialized to a |
| // fixed array (e.g. Heap::empty_fixed_array()). Currently, the object |
| // verification code has to cope with (temporarily) invalid objects. See |
| // for example, JSArray::JSArrayVerify). |
| InitializeJSObjectBody(obj, map, JSObject::kHeaderSize); |
| } |
| |
| |
| void Heap::InitializeJSObjectBody(JSObject* obj, Map* map, int start_offset) { |
| if (start_offset == map->instance_size()) return; |
| DCHECK_LT(start_offset, map->instance_size()); |
| |
| // We cannot always fill with one_pointer_filler_map because objects |
| // created from API functions expect their internal fields to be initialized |
| // with undefined_value. |
| // Pre-allocated fields need to be initialized with undefined_value as well |
| // so that object accesses before the constructor completes (e.g. in the |
| // debugger) will not cause a crash. |
| |
| // In case of Array subclassing the |map| could already be transitioned |
| // to different elements kind from the initial map on which we track slack. |
| bool in_progress = map->IsInobjectSlackTrackingInProgress(); |
| Object* filler; |
| if (in_progress) { |
| filler = one_pointer_filler_map(); |
| } else { |
| filler = undefined_value(); |
| } |
| obj->InitializeBody(map, start_offset, Heap::undefined_value(), filler); |
| if (in_progress) { |
| map->FindRootMap()->InobjectSlackTrackingStep(); |
| } |
| } |
| |
| |
| AllocationResult Heap::AllocateJSObjectFromMap( |
| Map* map, PretenureFlag pretenure, AllocationSite* allocation_site) { |
| // JSFunctions should be allocated using AllocateFunction to be |
| // properly initialized. |
| DCHECK(map->instance_type() != JS_FUNCTION_TYPE); |
| |
| // Both types of global objects should be allocated using |
| // AllocateGlobalObject to be properly initialized. |
| DCHECK(map->instance_type() != JS_GLOBAL_OBJECT_TYPE); |
| |
| // Allocate the backing storage for the properties. |
| FixedArray* properties = empty_fixed_array(); |
| |
| // Allocate the JSObject. |
| AllocationSpace space = SelectSpace(pretenure); |
| JSObject* js_obj = nullptr; |
| AllocationResult allocation = Allocate(map, space, allocation_site); |
| if (!allocation.To(&js_obj)) return allocation; |
| |
| // Initialize the JSObject. |
| InitializeJSObjectFromMap(js_obj, properties, map); |
| DCHECK(js_obj->HasFastElements() || js_obj->HasFixedTypedArrayElements() || |
| js_obj->HasFastStringWrapperElements() || |
| js_obj->HasFastArgumentsElements()); |
| return js_obj; |
| } |
| |
| |
| AllocationResult Heap::AllocateJSObject(JSFunction* constructor, |
| PretenureFlag pretenure, |
| AllocationSite* allocation_site) { |
| DCHECK(constructor->has_initial_map()); |
| |
| // Allocate the object based on the constructors initial map. |
| AllocationResult allocation = AllocateJSObjectFromMap( |
| constructor->initial_map(), pretenure, allocation_site); |
| #ifdef DEBUG |
| // Make sure result is NOT a global object if valid. |
| HeapObject* obj = nullptr; |
| DCHECK(!allocation.To(&obj) || !obj->IsJSGlobalObject()); |
| #endif |
| return allocation; |
| } |
| |
| |
| AllocationResult Heap::CopyJSObject(JSObject* source, AllocationSite* site) { |
| // Make the clone. |
| Map* map = source->map(); |
| |
| // We can only clone regexps, normal objects, api objects, errors or arrays. |
| // Copying anything else will break invariants. |
| CHECK(map->instance_type() == JS_REGEXP_TYPE || |
| map->instance_type() == JS_OBJECT_TYPE || |
| map->instance_type() == JS_ERROR_TYPE || |
| map->instance_type() == JS_ARRAY_TYPE || |
| map->instance_type() == JS_API_OBJECT_TYPE || |
| map->instance_type() == JS_SPECIAL_API_OBJECT_TYPE); |
| |
| int object_size = map->instance_size(); |
| HeapObject* clone = nullptr; |
| |
| DCHECK(site == NULL || AllocationSite::CanTrack(map->instance_type())); |
| |
| int adjusted_object_size = |
| site != NULL ? object_size + AllocationMemento::kSize : object_size; |
| AllocationResult allocation = AllocateRaw(adjusted_object_size, NEW_SPACE); |
| if (!allocation.To(&clone)) return allocation; |
| |
| SLOW_DCHECK(InNewSpace(clone)); |
| // Since we know the clone is allocated in new space, we can copy |
| // the contents without worrying about updating the write barrier. |
| CopyBlock(clone->address(), source->address(), object_size); |
| |
| if (site != NULL) { |
| AllocationMemento* alloc_memento = reinterpret_cast<AllocationMemento*>( |
| reinterpret_cast<Address>(clone) + object_size); |
| InitializeAllocationMemento(alloc_memento, site); |
| } |
| |
| SLOW_DCHECK(JSObject::cast(clone)->GetElementsKind() == |
| source->GetElementsKind()); |
| FixedArrayBase* elements = FixedArrayBase::cast(source->elements()); |
| FixedArray* properties = FixedArray::cast(source->properties()); |
| // Update elements if necessary. |
| if (elements->length() > 0) { |
| FixedArrayBase* elem = nullptr; |
| { |
| AllocationResult allocation; |
| if (elements->map() == fixed_cow_array_map()) { |
| allocation = FixedArray::cast(elements); |
| } else if (source->HasFastDoubleElements()) { |
| allocation = CopyFixedDoubleArray(FixedDoubleArray::cast(elements)); |
| } else { |
| allocation = CopyFixedArray(FixedArray::cast(elements)); |
| } |
| if (!allocation.To(&elem)) return allocation; |
| } |
| JSObject::cast(clone)->set_elements(elem, SKIP_WRITE_BARRIER); |
| } |
| // Update properties if necessary. |
| if (properties->length() > 0) { |
| FixedArray* prop = nullptr; |
| { |
| AllocationResult allocation = CopyFixedArray(properties); |
| if (!allocation.To(&prop)) return allocation; |
| } |
| JSObject::cast(clone)->set_properties(prop, SKIP_WRITE_BARRIER); |
| } |
| // Return the new clone. |
| return clone; |
| } |
| |
| |
| static inline void WriteOneByteData(Vector<const char> vector, uint8_t* chars, |
| int len) { |
| // Only works for one byte strings. |
| DCHECK(vector.length() == len); |
| MemCopy(chars, vector.start(), len); |
| } |
| |
| static inline void WriteTwoByteData(Vector<const char> vector, uint16_t* chars, |
| int len) { |
| const uint8_t* stream = reinterpret_cast<const uint8_t*>(vector.start()); |
| size_t stream_length = vector.length(); |
| while (stream_length != 0) { |
| size_t consumed = 0; |
| uint32_t c = unibrow::Utf8::ValueOf(stream, stream_length, &consumed); |
| DCHECK(c != unibrow::Utf8::kBadChar); |
| DCHECK(consumed <= stream_length); |
| stream_length -= consumed; |
| stream += consumed; |
| if (c > unibrow::Utf16::kMaxNonSurrogateCharCode) { |
| len -= 2; |
| if (len < 0) break; |
| *chars++ = unibrow::Utf16::LeadSurrogate(c); |
| *chars++ = unibrow::Utf16::TrailSurrogate(c); |
| } else { |
| len -= 1; |
| if (len < 0) break; |
| *chars++ = c; |
| } |
| } |
| DCHECK(stream_length == 0); |
| DCHECK(len == 0); |
| } |
| |
| |
| static inline void WriteOneByteData(String* s, uint8_t* chars, int len) { |
| DCHECK(s->length() == len); |
| String::WriteToFlat(s, chars, 0, len); |
| } |
| |
| |
| static inline void WriteTwoByteData(String* s, uint16_t* chars, int len) { |
| DCHECK(s->length() == len); |
| String::WriteToFlat(s, chars, 0, len); |
| } |
| |
| |
| template <bool is_one_byte, typename T> |
| AllocationResult Heap::AllocateInternalizedStringImpl(T t, int chars, |
| uint32_t hash_field) { |
| DCHECK(chars >= 0); |
| // Compute map and object size. |
| int size; |
| Map* map; |
| |
| DCHECK_LE(0, chars); |
| DCHECK_GE(String::kMaxLength, chars); |
| if (is_one_byte) { |
| map = one_byte_internalized_string_map(); |
| size = SeqOneByteString::SizeFor(chars); |
| } else { |
| map = internalized_string_map(); |
| size = SeqTwoByteString::SizeFor(chars); |
| } |
| |
| // Allocate string. |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| } |
| |
| result->set_map_no_write_barrier(map); |
| // Set length and hash fields of the allocated string. |
| String* answer = String::cast(result); |
| answer->set_length(chars); |
| answer->set_hash_field(hash_field); |
| |
| DCHECK_EQ(size, answer->Size()); |
| |
| if (is_one_byte) { |
| WriteOneByteData(t, SeqOneByteString::cast(answer)->GetChars(), chars); |
| } else { |
| WriteTwoByteData(t, SeqTwoByteString::cast(answer)->GetChars(), chars); |
| } |
| return answer; |
| } |
| |
| |
| // Need explicit instantiations. |
| template AllocationResult Heap::AllocateInternalizedStringImpl<true>(String*, |
| int, |
| uint32_t); |
| template AllocationResult Heap::AllocateInternalizedStringImpl<false>(String*, |
| int, |
| uint32_t); |
| template AllocationResult Heap::AllocateInternalizedStringImpl<false>( |
| Vector<const char>, int, uint32_t); |
| |
| |
| AllocationResult Heap::AllocateRawOneByteString(int length, |
| PretenureFlag pretenure) { |
| DCHECK_LE(0, length); |
| DCHECK_GE(String::kMaxLength, length); |
| int size = SeqOneByteString::SizeFor(length); |
| DCHECK(size <= SeqOneByteString::kMaxSize); |
| AllocationSpace space = SelectSpace(pretenure); |
| |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, space); |
| if (!allocation.To(&result)) return allocation; |
| } |
| |
| // Partially initialize the object. |
| result->set_map_no_write_barrier(one_byte_string_map()); |
| String::cast(result)->set_length(length); |
| String::cast(result)->set_hash_field(String::kEmptyHashField); |
| DCHECK_EQ(size, HeapObject::cast(result)->Size()); |
| |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateRawTwoByteString(int length, |
| PretenureFlag pretenure) { |
| DCHECK_LE(0, length); |
| DCHECK_GE(String::kMaxLength, length); |
| int size = SeqTwoByteString::SizeFor(length); |
| DCHECK(size <= SeqTwoByteString::kMaxSize); |
| AllocationSpace space = SelectSpace(pretenure); |
| |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, space); |
| if (!allocation.To(&result)) return allocation; |
| } |
| |
| // Partially initialize the object. |
| result->set_map_no_write_barrier(string_map()); |
| String::cast(result)->set_length(length); |
| String::cast(result)->set_hash_field(String::kEmptyHashField); |
| DCHECK_EQ(size, HeapObject::cast(result)->Size()); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateEmptyFixedArray() { |
| int size = FixedArray::SizeFor(0); |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| } |
| // Initialize the object. |
| result->set_map_no_write_barrier(fixed_array_map()); |
| FixedArray::cast(result)->set_length(0); |
| return result; |
| } |
| |
| AllocationResult Heap::AllocateEmptyScopeInfo() { |
| int size = FixedArray::SizeFor(0); |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| } |
| // Initialize the object. |
| result->set_map_no_write_barrier(scope_info_map()); |
| FixedArray::cast(result)->set_length(0); |
| return result; |
| } |
| |
| AllocationResult Heap::CopyAndTenureFixedCOWArray(FixedArray* src) { |
| if (!InNewSpace(src)) { |
| return src; |
| } |
| |
| int len = src->length(); |
| HeapObject* obj = nullptr; |
| { |
| AllocationResult allocation = AllocateRawFixedArray(len, TENURED); |
| if (!allocation.To(&obj)) return allocation; |
| } |
| obj->set_map_no_write_barrier(fixed_array_map()); |
| FixedArray* result = FixedArray::cast(obj); |
| result->set_length(len); |
| |
| // Copy the content. |
| DisallowHeapAllocation no_gc; |
| WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc); |
| for (int i = 0; i < len; i++) result->set(i, src->get(i), mode); |
| |
| // TODO(mvstanton): The map is set twice because of protection against calling |
| // set() on a COW FixedArray. Issue v8:3221 created to track this, and |
| // we might then be able to remove this whole method. |
| HeapObject::cast(obj)->set_map_no_write_barrier(fixed_cow_array_map()); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateEmptyFixedTypedArray( |
| ExternalArrayType array_type) { |
| return AllocateFixedTypedArray(0, array_type, false, TENURED); |
| } |
| |
| |
| AllocationResult Heap::CopyFixedArrayAndGrow(FixedArray* src, int grow_by, |
| PretenureFlag pretenure) { |
| int old_len = src->length(); |
| int new_len = old_len + grow_by; |
| DCHECK(new_len >= old_len); |
| HeapObject* obj = nullptr; |
| { |
| AllocationResult allocation = AllocateRawFixedArray(new_len, pretenure); |
| if (!allocation.To(&obj)) return allocation; |
| } |
| |
| obj->set_map_no_write_barrier(fixed_array_map()); |
| FixedArray* result = FixedArray::cast(obj); |
| result->set_length(new_len); |
| |
| // Copy the content. |
| DisallowHeapAllocation no_gc; |
| WriteBarrierMode mode = obj->GetWriteBarrierMode(no_gc); |
| for (int i = 0; i < old_len; i++) result->set(i, src->get(i), mode); |
| MemsetPointer(result->data_start() + old_len, undefined_value(), grow_by); |
| return result; |
| } |
| |
| AllocationResult Heap::CopyFixedArrayUpTo(FixedArray* src, int new_len, |
| PretenureFlag pretenure) { |
| if (new_len == 0) return empty_fixed_array(); |
| |
| DCHECK_LE(new_len, src->length()); |
| |
| HeapObject* obj = nullptr; |
| { |
| AllocationResult allocation = AllocateRawFixedArray(new_len, pretenure); |
| if (!allocation.To(&obj)) return allocation; |
| } |
| obj->set_map_no_write_barrier(fixed_array_map()); |
| |
| FixedArray* result = FixedArray::cast(obj); |
| result->set_length(new_len); |
| |
| // Copy the content. |
| DisallowHeapAllocation no_gc; |
| WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc); |
| for (int i = 0; i < new_len; i++) result->set(i, src->get(i), mode); |
| return result; |
| } |
| |
| AllocationResult Heap::CopyFixedArrayWithMap(FixedArray* src, Map* map) { |
| int len = src->length(); |
| HeapObject* obj = nullptr; |
| { |
| AllocationResult allocation = AllocateRawFixedArray(len, NOT_TENURED); |
| if (!allocation.To(&obj)) return allocation; |
| } |
| obj->set_map_no_write_barrier(map); |
| |
| FixedArray* result = FixedArray::cast(obj); |
| DisallowHeapAllocation no_gc; |
| WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc); |
| |
| // Eliminate the write barrier if possible. |
| if (mode == SKIP_WRITE_BARRIER) { |
| CopyBlock(obj->address() + kPointerSize, src->address() + kPointerSize, |
| FixedArray::SizeFor(len) - kPointerSize); |
| return obj; |
| } |
| |
| // Slow case: Just copy the content one-by-one. |
| result->set_length(len); |
| for (int i = 0; i < len; i++) result->set(i, src->get(i), mode); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::CopyFixedDoubleArrayWithMap(FixedDoubleArray* src, |
| Map* map) { |
| int len = src->length(); |
| HeapObject* obj = nullptr; |
| { |
| AllocationResult allocation = AllocateRawFixedDoubleArray(len, NOT_TENURED); |
| if (!allocation.To(&obj)) return allocation; |
| } |
| obj->set_map_no_write_barrier(map); |
| CopyBlock(obj->address() + FixedDoubleArray::kLengthOffset, |
| src->address() + FixedDoubleArray::kLengthOffset, |
| FixedDoubleArray::SizeFor(len) - FixedDoubleArray::kLengthOffset); |
| return obj; |
| } |
| |
| |
| AllocationResult Heap::AllocateRawFixedArray(int length, |
| PretenureFlag pretenure) { |
| if (length < 0 || length > FixedArray::kMaxLength) { |
| v8::internal::Heap::FatalProcessOutOfMemory("invalid array length", true); |
| } |
| int size = FixedArray::SizeFor(length); |
| AllocationSpace space = SelectSpace(pretenure); |
| |
| AllocationResult result = AllocateRaw(size, space); |
| if (!result.IsRetry() && size > kMaxRegularHeapObjectSize && |
| FLAG_use_marking_progress_bar) { |
| MemoryChunk* chunk = |
| MemoryChunk::FromAddress(result.ToObjectChecked()->address()); |
| chunk->SetFlag(MemoryChunk::HAS_PROGRESS_BAR); |
| } |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateFixedArrayWithFiller(int length, |
| PretenureFlag pretenure, |
| Object* filler) { |
| DCHECK(length >= 0); |
| DCHECK(empty_fixed_array()->IsFixedArray()); |
| if (length == 0) return empty_fixed_array(); |
| |
| DCHECK(!InNewSpace(filler)); |
| HeapObject* result = nullptr; |
| { |
| AllocationResult allocation = AllocateRawFixedArray(length, pretenure); |
| if (!allocation.To(&result)) return allocation; |
| } |
| |
| result->set_map_no_write_barrier(fixed_array_map()); |
| FixedArray* array = FixedArray::cast(result); |
| array->set_length(length); |
| MemsetPointer(array->data_start(), filler, length); |
| return array; |
| } |
| |
| |
| AllocationResult Heap::AllocateFixedArray(int length, PretenureFlag pretenure) { |
| return AllocateFixedArrayWithFiller(length, pretenure, undefined_value()); |
| } |
| |
| |
| AllocationResult Heap::AllocateUninitializedFixedArray(int length) { |
| if (length == 0) return empty_fixed_array(); |
| |
| HeapObject* obj = nullptr; |
| { |
| AllocationResult allocation = AllocateRawFixedArray(length, NOT_TENURED); |
| if (!allocation.To(&obj)) return allocation; |
| } |
| |
| obj->set_map_no_write_barrier(fixed_array_map()); |
| FixedArray::cast(obj)->set_length(length); |
| return obj; |
| } |
| |
| |
| AllocationResult Heap::AllocateUninitializedFixedDoubleArray( |
| int length, PretenureFlag pretenure) { |
| if (length == 0) return empty_fixed_array(); |
| |
| HeapObject* elements = nullptr; |
| AllocationResult allocation = AllocateRawFixedDoubleArray(length, pretenure); |
| if (!allocation.To(&elements)) return allocation; |
| |
| elements->set_map_no_write_barrier(fixed_double_array_map()); |
| FixedDoubleArray::cast(elements)->set_length(length); |
| return elements; |
| } |
| |
| |
| AllocationResult Heap::AllocateRawFixedDoubleArray(int length, |
| PretenureFlag pretenure) { |
| if (length < 0 || length > FixedDoubleArray::kMaxLength) { |
| v8::internal::Heap::FatalProcessOutOfMemory("invalid array length", true); |
| } |
| int size = FixedDoubleArray::SizeFor(length); |
| AllocationSpace space = SelectSpace(pretenure); |
| |
| HeapObject* object = nullptr; |
| { |
| AllocationResult allocation = AllocateRaw(size, space, kDoubleAligned); |
| if (!allocation.To(&object)) return allocation; |
| } |
| |
| return object; |
| } |
| |
| |
| AllocationResult Heap::AllocateSymbol() { |
| // Statically ensure that it is safe to allocate symbols in paged spaces. |
| STATIC_ASSERT(Symbol::kSize <= kMaxRegularHeapObjectSize); |
| |
| HeapObject* result = nullptr; |
| AllocationResult allocation = AllocateRaw(Symbol::kSize, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| |
| result->set_map_no_write_barrier(symbol_map()); |
| |
| // Generate a random hash value. |
| int hash = isolate()->GenerateIdentityHash(Name::kHashBitMask); |
| |
| Symbol::cast(result) |
| ->set_hash_field(Name::kIsNotArrayIndexMask | (hash << Name::kHashShift)); |
| Symbol::cast(result)->set_name(undefined_value()); |
| Symbol::cast(result)->set_flags(0); |
| |
| DCHECK(!Symbol::cast(result)->is_private()); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateStruct(InstanceType type) { |
| Map* map; |
| switch (type) { |
| #define MAKE_CASE(NAME, Name, name) \ |
| case NAME##_TYPE: \ |
| map = name##_map(); \ |
| break; |
| STRUCT_LIST(MAKE_CASE) |
| #undef MAKE_CASE |
| default: |
| UNREACHABLE(); |
| return exception(); |
| } |
| int size = map->instance_size(); |
| Struct* result = nullptr; |
| { |
| AllocationResult allocation = Allocate(map, OLD_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| } |
| result->InitializeBody(size); |
| return result; |
| } |
| |
| |
| void Heap::MakeHeapIterable() { |
| mark_compact_collector()->EnsureSweepingCompleted(); |
| } |
| |
| |
| static double ComputeMutatorUtilization(double mutator_speed, double gc_speed) { |
| const double kMinMutatorUtilization = 0.0; |
| const double kConservativeGcSpeedInBytesPerMillisecond = 200000; |
| if (mutator_speed == 0) return kMinMutatorUtilization; |
| if (gc_speed == 0) gc_speed = kConservativeGcSpeedInBytesPerMillisecond; |
| // Derivation: |
| // mutator_utilization = mutator_time / (mutator_time + gc_time) |
| // mutator_time = 1 / mutator_speed |
| // gc_time = 1 / gc_speed |
| // mutator_utilization = (1 / mutator_speed) / |
| // (1 / mutator_speed + 1 / gc_speed) |
| // mutator_utilization = gc_speed / (mutator_speed + gc_speed) |
| return gc_speed / (mutator_speed + gc_speed); |
| } |
| |
| |
| double Heap::YoungGenerationMutatorUtilization() { |
| double mutator_speed = static_cast<double>( |
| tracer()->NewSpaceAllocationThroughputInBytesPerMillisecond()); |
| double gc_speed = |
| tracer()->ScavengeSpeedInBytesPerMillisecond(kForSurvivedObjects); |
| double result = ComputeMutatorUtilization(mutator_speed, gc_speed); |
| if (FLAG_trace_mutator_utilization) { |
| isolate()->PrintWithTimestamp( |
| "Young generation mutator utilization = %.3f (" |
| "mutator_speed=%.f, gc_speed=%.f)\n", |
| result, mutator_speed, gc_speed); |
| } |
| return result; |
| } |
| |
| |
| double Heap::OldGenerationMutatorUtilization() { |
| double mutator_speed = static_cast<double>( |
| tracer()->OldGenerationAllocationThroughputInBytesPerMillisecond()); |
| double gc_speed = static_cast<double>( |
| tracer()->CombinedMarkCompactSpeedInBytesPerMillisecond()); |
| double result = ComputeMutatorUtilization(mutator_speed, gc_speed); |
| if (FLAG_trace_mutator_utilization) { |
| isolate()->PrintWithTimestamp( |
| "Old generation mutator utilization = %.3f (" |
| "mutator_speed=%.f, gc_speed=%.f)\n", |
| result, mutator_speed, gc_speed); |
| } |
| return result; |
| } |
| |
| |
| bool Heap::HasLowYoungGenerationAllocationRate() { |
| const double high_mutator_utilization = 0.993; |
| return YoungGenerationMutatorUtilization() > high_mutator_utilization; |
| } |
| |
| |
| bool Heap::HasLowOldGenerationAllocationRate() { |
| const double high_mutator_utilization = 0.993; |
| return OldGenerationMutatorUtilization() > high_mutator_utilization; |
| } |
| |
| |
| bool Heap::HasLowAllocationRate() { |
| return HasLowYoungGenerationAllocationRate() && |
| HasLowOldGenerationAllocationRate(); |
| } |
| |
| |
| bool Heap::HasHighFragmentation() { |
| size_t used = PromotedSpaceSizeOfObjects(); |
| size_t committed = CommittedOldGenerationMemory(); |
| return HasHighFragmentation(used, committed); |
| } |
| |
| bool Heap::HasHighFragmentation(size_t used, size_t committed) { |
| const size_t kSlack = 16 * MB; |
| // Fragmentation is high if committed > 2 * used + kSlack. |
| // Rewrite the exression to avoid overflow. |
| DCHECK_GE(committed, used); |
| return committed - used > used + kSlack; |
| } |
| |
| bool Heap::ShouldOptimizeForMemoryUsage() { |
| return FLAG_optimize_for_size || isolate()->IsIsolateInBackground() || |
| HighMemoryPressure() || IsLowMemoryDevice(); |
| } |
| |
| void Heap::ActivateMemoryReducerIfNeeded() { |
| // Activate memory reducer when switching to background if |
| // - there was no mark compact since the start. |
| // - the committed memory can be potentially reduced. |
| // 2 pages for the old, code, and map space + 1 page for new space. |
| const int kMinCommittedMemory = 7 * Page::kPageSize; |
| if (ms_count_ == 0 && CommittedMemory() > kMinCommittedMemory && |
| isolate()->IsIsolateInBackground()) { |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kPossibleGarbage; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| memory_reducer_->NotifyPossibleGarbage(event); |
| } |
| } |
| |
| void Heap::ReduceNewSpaceSize() { |
| // TODO(ulan): Unify this constant with the similar constant in |
| // GCIdleTimeHandler once the change is merged to 4.5. |
| static const size_t kLowAllocationThroughput = 1000; |
| const double allocation_throughput = |
| tracer()->CurrentAllocationThroughputInBytesPerMillisecond(); |
| |
| if (FLAG_predictable) return; |
| |
| if (ShouldReduceMemory() || |
| ((allocation_throughput != 0) && |
| (allocation_throughput < kLowAllocationThroughput))) { |
| new_space_->Shrink(); |
| UncommitFromSpace(); |
| } |
| } |
| |
| void Heap::FinalizeIncrementalMarkingIfComplete( |
| GarbageCollectionReason gc_reason) { |
| if (incremental_marking()->IsMarking() && |
| (incremental_marking()->IsReadyToOverApproximateWeakClosure() || |
| (!incremental_marking()->finalize_marking_completed() && |
| mark_compact_collector()->marking_deque()->IsEmpty() && |
| local_embedder_heap_tracer()->ShouldFinalizeIncrementalMarking()))) { |
| FinalizeIncrementalMarking(gc_reason); |
| } else if (incremental_marking()->IsComplete() || |
| (mark_compact_collector()->marking_deque()->IsEmpty() && |
| local_embedder_heap_tracer() |
| ->ShouldFinalizeIncrementalMarking())) { |
| CollectAllGarbage(current_gc_flags_, gc_reason); |
| } |
| } |
| |
| bool Heap::TryFinalizeIdleIncrementalMarking( |
| double idle_time_in_ms, GarbageCollectionReason gc_reason) { |
| size_t size_of_objects = static_cast<size_t>(SizeOfObjects()); |
| double final_incremental_mark_compact_speed_in_bytes_per_ms = |
| tracer()->FinalIncrementalMarkCompactSpeedInBytesPerMillisecond(); |
| if (incremental_marking()->IsReadyToOverApproximateWeakClosure() || |
| (!incremental_marking()->finalize_marking_completed() && |
| mark_compact_collector()->marking_deque()->IsEmpty() && |
| local_embedder_heap_tracer()->ShouldFinalizeIncrementalMarking() && |
| gc_idle_time_handler_->ShouldDoOverApproximateWeakClosure( |
| idle_time_in_ms))) { |
| FinalizeIncrementalMarking(gc_reason); |
| return true; |
| } else if (incremental_marking()->IsComplete() || |
| (mark_compact_collector()->marking_deque()->IsEmpty() && |
| local_embedder_heap_tracer() |
| ->ShouldFinalizeIncrementalMarking() && |
| gc_idle_time_handler_->ShouldDoFinalIncrementalMarkCompact( |
| idle_time_in_ms, size_of_objects, |
| final_incremental_mark_compact_speed_in_bytes_per_ms))) { |
| CollectAllGarbage(current_gc_flags_, gc_reason); |
| return true; |
| } |
| return false; |
| } |
| |
| void Heap::RegisterReservationsForBlackAllocation(Reservation* reservations) { |
| // TODO(hpayer): We do not have to iterate reservations on black objects |
| // for marking. We just have to execute the special visiting side effect |
| // code that adds objects to global data structures, e.g. for array buffers. |
| |
| if (incremental_marking()->black_allocation()) { |
| // Iterate black objects in old space, code space, map space, and large |
| // object space for side effects. |
| for (int i = OLD_SPACE; i < Serializer::kNumberOfSpaces; i++) { |
| const Heap::Reservation& res = reservations[i]; |
| for (auto& chunk : res) { |
| Address addr = chunk.start; |
| while (addr < chunk.end) { |
| HeapObject* obj = HeapObject::FromAddress(addr); |
| // There might be grey objects due to black to grey transitions in |
| // incremental marking. E.g. see VisitNativeContextIncremental. |
| DCHECK(ObjectMarking::IsBlackOrGrey(obj)); |
| if (ObjectMarking::IsBlack(obj)) { |
| incremental_marking()->IterateBlackObject(obj); |
| } |
| addr += obj->Size(); |
| } |
| } |
| } |
| } |
| } |
| |
| GCIdleTimeHeapState Heap::ComputeHeapState() { |
| GCIdleTimeHeapState heap_state; |
| heap_state.contexts_disposed = contexts_disposed_; |
| heap_state.contexts_disposal_rate = |
| tracer()->ContextDisposalRateInMilliseconds(); |
| heap_state.size_of_objects = static_cast<size_t>(SizeOfObjects()); |
| heap_state.incremental_marking_stopped = incremental_marking()->IsStopped(); |
| return heap_state; |
| } |
| |
| |
| bool Heap::PerformIdleTimeAction(GCIdleTimeAction action, |
| GCIdleTimeHeapState heap_state, |
| double deadline_in_ms) { |
| bool result = false; |
| switch (action.type) { |
| case DONE: |
| result = true; |
| break; |
| case DO_INCREMENTAL_STEP: { |
| const double remaining_idle_time_in_ms = |
| incremental_marking()->AdvanceIncrementalMarking( |
| deadline_in_ms, IncrementalMarking::NO_GC_VIA_STACK_GUARD, |
| IncrementalMarking::FORCE_COMPLETION, StepOrigin::kTask); |
| if (remaining_idle_time_in_ms > 0.0) { |
| TryFinalizeIdleIncrementalMarking( |
| remaining_idle_time_in_ms, |
| GarbageCollectionReason::kFinalizeMarkingViaTask); |
| } |
| result = incremental_marking()->IsStopped(); |
| break; |
| } |
| case DO_FULL_GC: { |
| DCHECK(contexts_disposed_ > 0); |
| HistogramTimerScope scope(isolate_->counters()->gc_context()); |
| TRACE_EVENT0("v8", "V8.GCContext"); |
| CollectAllGarbage(kNoGCFlags, GarbageCollectionReason::kContextDisposal); |
| break; |
| } |
| case DO_NOTHING: |
| break; |
| } |
| |
| return result; |
| } |
| |
| |
| void Heap::IdleNotificationEpilogue(GCIdleTimeAction action, |
| GCIdleTimeHeapState heap_state, |
| double start_ms, double deadline_in_ms) { |
| double idle_time_in_ms = deadline_in_ms - start_ms; |
| double current_time = MonotonicallyIncreasingTimeInMs(); |
| last_idle_notification_time_ = current_time; |
| double deadline_difference = deadline_in_ms - current_time; |
| |
| contexts_disposed_ = 0; |
| |
| isolate()->counters()->gc_idle_time_allotted_in_ms()->AddSample( |
| static_cast<int>(idle_time_in_ms)); |
| |
| if (deadline_in_ms - start_ms > |
| GCIdleTimeHandler::kMaxFrameRenderingIdleTime) { |
| int committed_memory = static_cast<int>(CommittedMemory() / KB); |
| int used_memory = static_cast<int>(heap_state.size_of_objects / KB); |
| isolate()->counters()->aggregated_memory_heap_committed()->AddSample( |
| start_ms, committed_memory); |
| isolate()->counters()->aggregated_memory_heap_used()->AddSample( |
| start_ms, used_memory); |
| } |
| |
| if (deadline_difference >= 0) { |
| if (action.type != DONE && action.type != DO_NOTHING) { |
| isolate()->counters()->gc_idle_time_limit_undershot()->AddSample( |
| static_cast<int>(deadline_difference)); |
| } |
| } else { |
| isolate()->counters()->gc_idle_time_limit_overshot()->AddSample( |
| static_cast<int>(-deadline_difference)); |
| } |
| |
| if ((FLAG_trace_idle_notification && action.type > DO_NOTHING) || |
| FLAG_trace_idle_notification_verbose) { |
| isolate_->PrintWithTimestamp( |
| "Idle notification: requested idle time %.2f ms, used idle time %.2f " |
| "ms, deadline usage %.2f ms [", |
| idle_time_in_ms, idle_time_in_ms - deadline_difference, |
| deadline_difference); |
| action.Print(); |
| PrintF("]"); |
| if (FLAG_trace_idle_notification_verbose) { |
| PrintF("["); |
| heap_state.Print(); |
| PrintF("]"); |
| } |
| PrintF("\n"); |
| } |
| } |
| |
| |
| double Heap::MonotonicallyIncreasingTimeInMs() { |
| return V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() * |
| static_cast<double>(base::Time::kMillisecondsPerSecond); |
| } |
| |
| |
| bool Heap::IdleNotification(int idle_time_in_ms) { |
| return IdleNotification( |
| V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() + |
| (static_cast<double>(idle_time_in_ms) / |
| static_cast<double>(base::Time::kMillisecondsPerSecond))); |
| } |
| |
| |
| bool Heap::IdleNotification(double deadline_in_seconds) { |
| CHECK(HasBeenSetUp()); |
| double deadline_in_ms = |
| deadline_in_seconds * |
| static_cast<double>(base::Time::kMillisecondsPerSecond); |
| HistogramTimerScope idle_notification_scope( |
| isolate_->counters()->gc_idle_notification()); |
| TRACE_EVENT0("v8", "V8.GCIdleNotification"); |
| double start_ms = MonotonicallyIncreasingTimeInMs(); |
| double idle_time_in_ms = deadline_in_ms - start_ms; |
| |
| tracer()->SampleAllocation(start_ms, NewSpaceAllocationCounter(), |
| OldGenerationAllocationCounter()); |
| |
| GCIdleTimeHeapState heap_state = ComputeHeapState(); |
| |
| GCIdleTimeAction action = |
| gc_idle_time_handler_->Compute(idle_time_in_ms, heap_state); |
| |
| bool result = PerformIdleTimeAction(action, heap_state, deadline_in_ms); |
| |
| IdleNotificationEpilogue(action, heap_state, start_ms, deadline_in_ms); |
| return result; |
| } |
| |
| |
| bool Heap::RecentIdleNotificationHappened() { |
| return (last_idle_notification_time_ + |
| GCIdleTimeHandler::kMaxScheduledIdleTime) > |
| MonotonicallyIncreasingTimeInMs(); |
| } |
| |
| class MemoryPressureInterruptTask : public CancelableTask { |
| public: |
| explicit MemoryPressureInterruptTask(Heap* heap) |
| : CancelableTask(heap->isolate()), heap_(heap) {} |
| |
| virtual ~MemoryPressureInterruptTask() {} |
| |
| private: |
| // v8::internal::CancelableTask overrides. |
| void RunInternal() override { heap_->CheckMemoryPressure(); } |
| |
| Heap* heap_; |
| DISALLOW_COPY_AND_ASSIGN(MemoryPressureInterruptTask); |
| }; |
| |
| void Heap::CheckMemoryPressure() { |
| if (HighMemoryPressure()) { |
| if (isolate()->concurrent_recompilation_enabled()) { |
| // The optimizing compiler may be unnecessarily holding on to memory. |
| DisallowHeapAllocation no_recursive_gc; |
| isolate()->optimizing_compile_dispatcher()->Flush( |
| OptimizingCompileDispatcher::BlockingBehavior::kDontBlock); |
| } |
| } |
| if (memory_pressure_level_.Value() == MemoryPressureLevel::kCritical) { |
| CollectGarbageOnMemoryPressure(); |
| } else if (memory_pressure_level_.Value() == MemoryPressureLevel::kModerate) { |
| if (FLAG_incremental_marking && incremental_marking()->IsStopped()) { |
| StartIncrementalMarking(kReduceMemoryFootprintMask, |
| GarbageCollectionReason::kMemoryPressure); |
| } |
| } |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kPossibleGarbage; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| memory_reducer_->NotifyPossibleGarbage(event); |
| } |
| |
| void Heap::CollectGarbageOnMemoryPressure() { |
| const int kGarbageThresholdInBytes = 8 * MB; |
| const double kGarbageThresholdAsFractionOfTotalMemory = 0.1; |
| // This constant is the maximum response time in RAIL performance model. |
| const double kMaxMemoryPressurePauseMs = 100; |
| |
| double start = MonotonicallyIncreasingTimeInMs(); |
| CollectAllGarbage(kReduceMemoryFootprintMask | kAbortIncrementalMarkingMask, |
| GarbageCollectionReason::kMemoryPressure, |
| kGCCallbackFlagCollectAllAvailableGarbage); |
| double end = MonotonicallyIncreasingTimeInMs(); |
| |
| // Estimate how much memory we can free. |
| int64_t potential_garbage = |
| (CommittedMemory() - SizeOfObjects()) + external_memory_; |
| // If we can potentially free large amount of memory, then start GC right |
| // away instead of waiting for memory reducer. |
| if (potential_garbage >= kGarbageThresholdInBytes && |
| potential_garbage >= |
| CommittedMemory() * kGarbageThresholdAsFractionOfTotalMemory) { |
| // If we spent less than half of the time budget, then perform full GC |
| // Otherwise, start incremental marking. |
| if (end - start < kMaxMemoryPressurePauseMs / 2) { |
| CollectAllGarbage( |
| kReduceMemoryFootprintMask | kAbortIncrementalMarkingMask, |
| GarbageCollectionReason::kMemoryPressure, |
| kGCCallbackFlagCollectAllAvailableGarbage); |
| } else { |
| if (FLAG_incremental_marking && incremental_marking()->IsStopped()) { |
| StartIncrementalMarking(kReduceMemoryFootprintMask, |
| GarbageCollectionReason::kMemoryPressure); |
| } |
| } |
| } |
| } |
| |
| void Heap::MemoryPressureNotification(MemoryPressureLevel level, |
| bool is_isolate_locked) { |
| MemoryPressureLevel previous = memory_pressure_level_.Value(); |
| memory_pressure_level_.SetValue(level); |
| if ((previous != MemoryPressureLevel::kCritical && |
| level == MemoryPressureLevel::kCritical) || |
| (previous == MemoryPressureLevel::kNone && |
| level == MemoryPressureLevel::kModerate)) { |
| if (is_isolate_locked) { |
| CheckMemoryPressure(); |
| } else { |
| ExecutionAccess access(isolate()); |
| isolate()->stack_guard()->RequestGC(); |
| V8::GetCurrentPlatform()->CallOnForegroundThread( |
| reinterpret_cast<v8::Isolate*>(isolate()), |
| new MemoryPressureInterruptTask(this)); |
| } |
| } |
| } |
| |
| void Heap::SetOutOfMemoryCallback(v8::debug::OutOfMemoryCallback callback, |
| void* data) { |
| out_of_memory_callback_ = callback; |
| out_of_memory_callback_data_ = data; |
| } |
| |
| void Heap::InvokeOutOfMemoryCallback() { |
| if (out_of_memory_callback_) { |
| out_of_memory_callback_(out_of_memory_callback_data_); |
| } |
| } |
| |
| void Heap::CollectCodeStatistics() { |
| CodeStatistics::ResetCodeAndMetadataStatistics(isolate()); |
| // We do not look for code in new space, or map space. If code |
| // somehow ends up in those spaces, we would miss it here. |
| CodeStatistics::CollectCodeStatistics(code_space_, isolate()); |
| CodeStatistics::CollectCodeStatistics(old_space_, isolate()); |
| CodeStatistics::CollectCodeStatistics(lo_space_, isolate()); |
| } |
| |
| #ifdef DEBUG |
| |
| void Heap::Print() { |
| if (!HasBeenSetUp()) return; |
| isolate()->PrintStack(stdout); |
| AllSpaces spaces(this); |
| for (Space* space = spaces.next(); space != NULL; space = spaces.next()) { |
| space->Print(); |
| } |
| } |
| |
| |
| void Heap::ReportCodeStatistics(const char* title) { |
| PrintF(">>>>>> Code Stats (%s) >>>>>>\n", title); |
| CollectCodeStatistics(); |
| CodeStatistics::ReportCodeStatistics(isolate()); |
| } |
| |
| |
| // This function expects that NewSpace's allocated objects histogram is |
| // populated (via a call to CollectStatistics or else as a side effect of a |
| // just-completed scavenge collection). |
| void Heap::ReportHeapStatistics(const char* title) { |
| USE(title); |
| PrintF(">>>>>> =============== %s (%d) =============== >>>>>>\n", title, |
| gc_count_); |
| PrintF("old_generation_allocation_limit_ %" V8PRIdPTR "\n", |
| old_generation_allocation_limit_); |
| |
| PrintF("\n"); |
| PrintF("Number of handles : %d\n", HandleScope::NumberOfHandles(isolate_)); |
| isolate_->global_handles()->PrintStats(); |
| PrintF("\n"); |
| |
| PrintF("Heap statistics : "); |
| memory_allocator()->ReportStatistics(); |
| PrintF("To space : "); |
| new_space_->ReportStatistics(); |
| PrintF("Old space : "); |
| old_space_->ReportStatistics(); |
| PrintF("Code space : "); |
| code_space_->ReportStatistics(); |
| PrintF("Map space : "); |
| map_space_->ReportStatistics(); |
| PrintF("Large object space : "); |
| lo_space_->ReportStatistics(); |
| PrintF(">>>>>> ========================================= >>>>>>\n"); |
| } |
| |
| #endif // DEBUG |
| |
| const char* Heap::GarbageCollectionReasonToString( |
| GarbageCollectionReason gc_reason) { |
| switch (gc_reason) { |
| case GarbageCollectionReason::kAllocationFailure: |
| return "allocation failure"; |
| case GarbageCollectionReason::kAllocationLimit: |
| return "allocation limit"; |
| case GarbageCollectionReason::kContextDisposal: |
| return "context disposal"; |
| case GarbageCollectionReason::kCountersExtension: |
| return "counters extension"; |
| case GarbageCollectionReason::kDebugger: |
| return "debugger"; |
| case GarbageCollectionReason::kDeserializer: |
| return "deserialize"; |
| case GarbageCollectionReason::kExternalMemoryPressure: |
| return "external memory pressure"; |
| case GarbageCollectionReason::kFinalizeMarkingViaStackGuard: |
| return "finalize incremental marking via stack guard"; |
| case GarbageCollectionReason::kFinalizeMarkingViaTask: |
| return "finalize incremental marking via task"; |
| case GarbageCollectionReason::kFullHashtable: |
| return "full hash-table"; |
| case GarbageCollectionReason::kHeapProfiler: |
| return "heap profiler"; |
| case GarbageCollectionReason::kIdleTask: |
| return "idle task"; |
| case GarbageCollectionReason::kLastResort: |
| return "last resort"; |
| case GarbageCollectionReason::kLowMemoryNotification: |
| return "low memory notification"; |
| case GarbageCollectionReason::kMakeHeapIterable: |
| return "make heap iterable"; |
| case GarbageCollectionReason::kMemoryPressure: |
| return "memory pressure"; |
| case GarbageCollectionReason::kMemoryReducer: |
| return "memory reducer"; |
| case GarbageCollectionReason::kRuntime: |
| return "runtime"; |
| case GarbageCollectionReason::kSamplingProfiler: |
| return "sampling profiler"; |
| case GarbageCollectionReason::kSnapshotCreator: |
| return "snapshot creator"; |
| case GarbageCollectionReason::kTesting: |
| return "testing"; |
| case GarbageCollectionReason::kUnknown: |
| return "unknown"; |
| } |
| UNREACHABLE(); |
| return ""; |
| } |
| |
| bool Heap::Contains(HeapObject* value) { |
| if (memory_allocator()->IsOutsideAllocatedSpace(value->address())) { |
| return false; |
| } |
| return HasBeenSetUp() && |
| (new_space_->ToSpaceContains(value) || old_space_->Contains(value) || |
| code_space_->Contains(value) || map_space_->Contains(value) || |
| lo_space_->Contains(value)); |
| } |
| |
| bool Heap::ContainsSlow(Address addr) { |
| if (memory_allocator()->IsOutsideAllocatedSpace(addr)) { |
| return false; |
| } |
| return HasBeenSetUp() && |
| (new_space_->ToSpaceContainsSlow(addr) || |
| old_space_->ContainsSlow(addr) || code_space_->ContainsSlow(addr) || |
| map_space_->ContainsSlow(addr) || lo_space_->ContainsSlow(addr)); |
| } |
| |
| bool Heap::InSpace(HeapObject* value, AllocationSpace space) { |
| if (memory_allocator()->IsOutsideAllocatedSpace(value->address())) { |
| return false; |
| } |
| if (!HasBeenSetUp()) return false; |
| |
| switch (space) { |
| case NEW_SPACE: |
| return new_space_->ToSpaceContains(value); |
| case OLD_SPACE: |
| return old_space_->Contains(value); |
| case CODE_SPACE: |
| return code_space_->Contains(value); |
| case MAP_SPACE: |
| return map_space_->Contains(value); |
| case LO_SPACE: |
| return lo_space_->Contains(value); |
| } |
| UNREACHABLE(); |
| return false; |
| } |
| |
| bool Heap::InSpaceSlow(Address addr, AllocationSpace space) { |
| if (memory_allocator()->IsOutsideAllocatedSpace(addr)) { |
| return false; |
| } |
| if (!HasBeenSetUp()) return false; |
| |
| switch (space) { |
| case NEW_SPACE: |
| return new_space_->ToSpaceContainsSlow(addr); |
| case OLD_SPACE: |
| return old_space_->ContainsSlow(addr); |
| case CODE_SPACE: |
| return code_space_->ContainsSlow(addr); |
| case MAP_SPACE: |
| return map_space_->ContainsSlow(addr); |
| case LO_SPACE: |
| return lo_space_->ContainsSlow(addr); |
| } |
| UNREACHABLE(); |
| return false; |
| } |
| |
| |
| bool Heap::IsValidAllocationSpace(AllocationSpace space) { |
| switch (space) { |
| case NEW_SPACE: |
| case OLD_SPACE: |
| case CODE_SPACE: |
| case MAP_SPACE: |
| case LO_SPACE: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| |
| bool Heap::RootIsImmortalImmovable(int root_index) { |
| switch (root_index) { |
| #define IMMORTAL_IMMOVABLE_ROOT(name) case Heap::k##name##RootIndex: |
| IMMORTAL_IMMOVABLE_ROOT_LIST(IMMORTAL_IMMOVABLE_ROOT) |
| #undef IMMORTAL_IMMOVABLE_ROOT |
| #define INTERNALIZED_STRING(name, value) case Heap::k##name##RootIndex: |
| INTERNALIZED_STRING_LIST(INTERNALIZED_STRING) |
| #undef INTERNALIZED_STRING |
| #define STRING_TYPE(NAME, size, name, Name) case Heap::k##Name##MapRootIndex: |
| STRING_TYPE_LIST(STRING_TYPE) |
| #undef STRING_TYPE |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| |
| #ifdef VERIFY_HEAP |
| void Heap::Verify() { |
| CHECK(HasBeenSetUp()); |
| HandleScope scope(isolate()); |
| |
| // We have to wait here for the sweeper threads to have an iterable heap. |
| mark_compact_collector()->EnsureSweepingCompleted(); |
| |
| VerifyPointersVisitor visitor; |
| IterateRoots(&visitor, VISIT_ONLY_STRONG); |
| |
| VerifySmisVisitor smis_visitor; |
| IterateSmiRoots(&smis_visitor); |
| |
| new_space_->Verify(); |
| |
| old_space_->Verify(&visitor); |
| map_space_->Verify(&visitor); |
| |
| VerifyPointersVisitor no_dirty_regions_visitor; |
| code_space_->Verify(&no_dirty_regions_visitor); |
| |
| lo_space_->Verify(); |
| |
| mark_compact_collector()->VerifyWeakEmbeddedObjectsInCode(); |
| if (FLAG_omit_map_checks_for_leaf_maps) { |
| mark_compact_collector()->VerifyOmittedMapChecks(); |
| } |
| } |
| #endif |
| |
| |
| void Heap::ZapFromSpace() { |
| if (!new_space_->IsFromSpaceCommitted()) return; |
| for (Page* page : |
| PageRange(new_space_->FromSpaceStart(), new_space_->FromSpaceEnd())) { |
| for (Address cursor = page->area_start(), limit = page->area_end(); |
| cursor < limit; cursor += kPointerSize) { |
| Memory::Address_at(cursor) = kFromSpaceZapValue; |
| } |
| } |
| } |
| |
| class IterateAndScavengePromotedObjectsVisitor final : public ObjectVisitor { |
| public: |
| IterateAndScavengePromotedObjectsVisitor(Heap* heap, HeapObject* target, |
| bool record_slots) |
| : heap_(heap), target_(target), record_slots_(record_slots) {} |
| |
| inline void VisitPointers(Object** start, Object** end) override { |
| Address slot_address = reinterpret_cast<Address>(start); |
| Page* page = Page::FromAddress(slot_address); |
| |
| while (slot_address < reinterpret_cast<Address>(end)) { |
| Object** slot = reinterpret_cast<Object**>(slot_address); |
| Object* target = *slot; |
| |
| if (target->IsHeapObject()) { |
| if (heap_->InFromSpace(target)) { |
| Scavenger::ScavengeObject(reinterpret_cast<HeapObject**>(slot), |
| HeapObject::cast(target)); |
| target = *slot; |
| if (heap_->InNewSpace(target)) { |
| SLOW_DCHECK(heap_->InToSpace(target)); |
| SLOW_DCHECK(target->IsHeapObject()); |
| RememberedSet<OLD_TO_NEW>::Insert(page, slot_address); |
| } |
| SLOW_DCHECK(!MarkCompactCollector::IsOnEvacuationCandidate( |
| HeapObject::cast(target))); |
| } else if (record_slots_ && |
| MarkCompactCollector::IsOnEvacuationCandidate( |
| HeapObject::cast(target))) { |
| heap_->mark_compact_collector()->RecordSlot(target_, slot, target); |
| } |
| } |
| |
| slot_address += kPointerSize; |
| } |
| } |
| |
| inline void VisitCodeEntry(Address code_entry_slot) override { |
| // Black allocation requires us to process objects referenced by |
| // promoted objects. |
| if (heap_->incremental_marking()->black_allocation()) { |
| Code* code = Code::cast(Code::GetObjectFromEntryAddress(code_entry_slot)); |
| IncrementalMarking::MarkGrey(heap_, code); |
| } |
| } |
| |
| private: |
| Heap* heap_; |
| HeapObject* target_; |
| bool record_slots_; |
| }; |
| |
| void Heap::IterateAndScavengePromotedObject(HeapObject* target, int size, |
| bool was_marked_black) { |
| // We are not collecting slots on new space objects during mutation |
| // thus we have to scan for pointers to evacuation candidates when we |
| // promote objects. But we should not record any slots in non-black |
| // objects. Grey object's slots would be rescanned. |
| // White object might not survive until the end of collection |
| // it would be a violation of the invariant to record it's slots. |
| bool record_slots = false; |
| if (incremental_marking()->IsCompacting()) { |
| record_slots = ObjectMarking::IsBlack(target); |
| } |
| |
| IterateAndScavengePromotedObjectsVisitor visitor(this, target, record_slots); |
| if (target->IsJSFunction()) { |
| // JSFunctions reachable through kNextFunctionLinkOffset are weak. Slots for |
| // this links are recorded during processing of weak lists. |
| JSFunction::BodyDescriptorWeakCode::IterateBody(target, size, &visitor); |
| } else { |
| target->IterateBody(target->map()->instance_type(), size, &visitor); |
| } |
| |
| // When black allocations is on, we have to visit not already marked black |
| // objects (in new space) promoted to black pages to keep their references |
| // alive. |
| // TODO(hpayer): Implement a special promotion visitor that incorporates |
| // regular visiting and IteratePromotedObjectPointers. |
| if (!was_marked_black) { |
| if (incremental_marking()->black_allocation()) { |
| IncrementalMarking::MarkGrey(this, target->map()); |
| incremental_marking()->IterateBlackObject(target); |
| } |
| } |
| } |
| |
| |
| void Heap::IterateRoots(ObjectVisitor* v, VisitMode mode) { |
| IterateStrongRoots(v, mode); |
| IterateWeakRoots(v, mode); |
| } |
| |
| |
| void Heap::IterateWeakRoots(ObjectVisitor* v, VisitMode mode) { |
| v->VisitPointer(reinterpret_cast<Object**>(&roots_[kStringTableRootIndex])); |
| v->Synchronize(VisitorSynchronization::kStringTable); |
| if (mode != VISIT_ALL_IN_SCAVENGE && mode != VISIT_ALL_IN_SWEEP_NEWSPACE) { |
| // Scavenge collections have special processing for this. |
| external_string_table_.IterateAll(v); |
| } |
| v->Synchronize(VisitorSynchronization::kExternalStringsTable); |
| } |
| |
| |
| void Heap::IterateSmiRoots(ObjectVisitor* v) { |
| // Acquire execution access since we are going to read stack limit values. |
| ExecutionAccess access(isolate()); |
| v->VisitPointers(&roots_[kSmiRootsStart], &roots_[kRootListLength]); |
| v->Synchronize(VisitorSynchronization::kSmiRootList); |
| } |
| |
| // We cannot avoid stale handles to left-trimmed objects, but can only make |
| // sure all handles still needed are updated. Filter out a stale pointer |
| // and clear the slot to allow post processing of handles (needed because |
| // the sweeper might actually free the underlying page). |
| class FixStaleLeftTrimmedHandlesVisitor : public ObjectVisitor { |
| public: |
| explicit FixStaleLeftTrimmedHandlesVisitor(Heap* heap) : heap_(heap) { |
| USE(heap_); |
| } |
| |
| void VisitPointer(Object** p) override { FixHandle(p); } |
| |
| void VisitPointers(Object** start, Object** end) override { |
| for (Object** p = start; p < end; p++) FixHandle(p); |
| } |
| |
| private: |
| inline void FixHandle(Object** p) { |
| HeapObject* current = reinterpret_cast<HeapObject*>(*p); |
| if (!current->IsHeapObject()) return; |
| const MapWord map_word = current->map_word(); |
| if (!map_word.IsForwardingAddress() && current->IsFiller()) { |
| #ifdef DEBUG |
| // We need to find a FixedArrayBase map after walking the fillers. |
| while (current->IsFiller()) { |
| Address next = reinterpret_cast<Address>(current); |
| if (current->map() == heap_->one_pointer_filler_map()) { |
| next += kPointerSize; |
| } else if (current->map() == heap_->two_pointer_filler_map()) { |
| next += 2 * kPointerSize; |
| } else { |
| next += current->Size(); |
| } |
| current = reinterpret_cast<HeapObject*>(next); |
| } |
| DCHECK(current->IsFixedArrayBase()); |
| #endif // DEBUG |
| *p = nullptr; |
| } |
| } |
| |
| Heap* heap_; |
| }; |
| |
| void Heap::IterateStrongRoots(ObjectVisitor* v, VisitMode mode) { |
| v->VisitPointers(&roots_[0], &roots_[kStrongRootListLength]); |
| v->Synchronize(VisitorSynchronization::kStrongRootList); |
| // The serializer/deserializer iterates the root list twice, first to pick |
| // off immortal immovable roots to make sure they end up on the first page, |
| // and then again for the rest. |
| if (mode == VISIT_ONLY_STRONG_ROOT_LIST) return; |
| |
| isolate_->bootstrapper()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kBootstrapper); |
| isolate_->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kTop); |
| Relocatable::Iterate(isolate_, v); |
| v->Synchronize(VisitorSynchronization::kRelocatable); |
| isolate_->debug()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kDebug); |
| |
| isolate_->compilation_cache()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kCompilationCache); |
| |
| // Iterate over local handles in handle scopes. |
| FixStaleLeftTrimmedHandlesVisitor left_trim_visitor(this); |
| isolate_->handle_scope_implementer()->Iterate(&left_trim_visitor); |
| isolate_->handle_scope_implementer()->Iterate(v); |
| isolate_->IterateDeferredHandles(v); |
| v->Synchronize(VisitorSynchronization::kHandleScope); |
| |
| // Iterate over the builtin code objects and code stubs in the |
| // heap. Note that it is not necessary to iterate over code objects |
| // on scavenge collections. |
| if (mode != VISIT_ALL_IN_SCAVENGE) { |
| isolate_->builtins()->IterateBuiltins(v); |
| v->Synchronize(VisitorSynchronization::kBuiltins); |
| isolate_->interpreter()->IterateDispatchTable(v); |
| v->Synchronize(VisitorSynchronization::kDispatchTable); |
| } |
| |
| // Iterate over global handles. |
| switch (mode) { |
| case VISIT_ONLY_STRONG_ROOT_LIST: |
| UNREACHABLE(); |
| break; |
| case VISIT_ONLY_STRONG_FOR_SERIALIZATION: |
| break; |
| case VISIT_ONLY_STRONG: |
| isolate_->global_handles()->IterateStrongRoots(v); |
| break; |
| case VISIT_ALL_IN_SCAVENGE: |
| isolate_->global_handles()->IterateNewSpaceStrongAndDependentRoots(v); |
| break; |
| case VISIT_ALL_IN_SWEEP_NEWSPACE: |
| case VISIT_ALL: |
| isolate_->global_handles()->IterateAllRoots(v); |
| break; |
| } |
| v->Synchronize(VisitorSynchronization::kGlobalHandles); |
| |
| // Iterate over eternal handles. |
| if (mode == VISIT_ALL_IN_SCAVENGE) { |
| isolate_->eternal_handles()->IterateNewSpaceRoots(v); |
| } else { |
| isolate_->eternal_handles()->IterateAllRoots(v); |
| } |
| v->Synchronize(VisitorSynchronization::kEternalHandles); |
| |
| // Iterate over pointers being held by inactive threads. |
| isolate_->thread_manager()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kThreadManager); |
| |
| // Iterate over other strong roots (currently only identity maps). |
| for (StrongRootsList* list = strong_roots_list_; list; list = list->next) { |
| v->VisitPointers(list->start, list->end); |
| } |
| v->Synchronize(VisitorSynchronization::kStrongRoots); |
| |
| // Iterate over the partial snapshot cache unless serializing. |
| if (mode != VISIT_ONLY_STRONG_FOR_SERIALIZATION) { |
| SerializerDeserializer::Iterate(isolate_, v); |
| } |
| // We don't do a v->Synchronize call here, because in debug mode that will |
| // output a flag to the snapshot. However at this point the serializer and |
| // deserializer are deliberately a little unsynchronized (see above) so the |
| // checking of the sync flag in the snapshot would fail. |
| } |
| |
| |
| // TODO(1236194): Since the heap size is configurable on the command line |
| // and through the API, we should gracefully handle the case that the heap |
| // size is not big enough to fit all the initial objects. |
| bool Heap::ConfigureHeap(size_t max_semi_space_size, size_t max_old_space_size, |
| size_t max_executable_size, size_t code_range_size) { |
| if (HasBeenSetUp()) return false; |
| |
| // Overwrite default configuration. |
| if (max_semi_space_size != 0) { |
| max_semi_space_size_ = max_semi_space_size * MB; |
| } |
| if (max_old_space_size != 0) { |
| max_old_generation_size_ = max_old_space_size * MB; |
| } |
| if (max_executable_size != 0) { |
| max_executable_size_ = max_executable_size * MB; |
| } |
| |
| // If max space size flags are specified overwrite the configuration. |
| if (FLAG_max_semi_space_size > 0) { |
| max_semi_space_size_ = static_cast<size_t>(FLAG_max_semi_space_size) * MB; |
| } |
| if (FLAG_max_old_space_size > 0) { |
| max_old_generation_size_ = |
| static_cast<size_t>(FLAG_max_old_space_size) * MB; |
| } |
| if (FLAG_max_executable_size > 0) { |
| max_executable_size_ = static_cast<size_t>(FLAG_max_executable_size) * MB; |
| } |
| |
| if (Page::kPageSize > MB) { |
| max_semi_space_size_ = ROUND_UP(max_semi_space_size_, Page::kPageSize); |
| max_old_generation_size_ = |
| ROUND_UP(max_old_generation_size_, Page::kPageSize); |
| max_executable_size_ = ROUND_UP(max_executable_size_, Page::kPageSize); |
| } |
| |
| if (FLAG_stress_compaction) { |
| // This will cause more frequent GCs when stressing. |
| max_semi_space_size_ = MB; |
| } |
| |
| // The new space size must be a power of two to support single-bit testing |
| // for containment. |
| max_semi_space_size_ = base::bits::RoundUpToPowerOfTwo32( |
| static_cast<uint32_t>(max_semi_space_size_)); |
| |
| if (FLAG_min_semi_space_size > 0) { |
| size_t initial_semispace_size = |
| static_cast<size_t>(FLAG_min_semi_space_size) * MB; |
| if (initial_semispace_size > max_semi_space_size_) { |
| initial_semispace_size_ = max_semi_space_size_; |
| if (FLAG_trace_gc) { |
| PrintIsolate(isolate_, |
| "Min semi-space size cannot be more than the maximum " |
| "semi-space size of %" PRIuS " MB\n", |
| max_semi_space_size_ / MB); |
| } |
| } else { |
| initial_semispace_size_ = |
| ROUND_UP(initial_semispace_size, Page::kPageSize); |
| } |
| } |
| |
| initial_semispace_size_ = Min(initial_semispace_size_, max_semi_space_size_); |
| |
| if (FLAG_semi_space_growth_factor < 2) { |
| FLAG_semi_space_growth_factor = 2; |
| } |
| |
| // The old generation is paged and needs at least one page for each space. |
| int paged_space_count = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1; |
| initial_max_old_generation_size_ = max_old_generation_size_ = |
| Max(static_cast<size_t>(paged_space_count * Page::kPageSize), |
| max_old_generation_size_); |
| |
| // The max executable size must be less than or equal to the max old |
| // generation size. |
| if (max_executable_size_ > max_old_generation_size_) { |
| max_executable_size_ = max_old_generation_size_; |
| } |
| |
| if (FLAG_initial_old_space_size > 0) { |
| initial_old_generation_size_ = FLAG_initial_old_space_size * MB; |
| } else { |
| initial_old_generation_size_ = |
| max_old_generation_size_ / kInitalOldGenerationLimitFactor; |
| } |
| old_generation_allocation_limit_ = initial_old_generation_size_; |
| |
| // We rely on being able to allocate new arrays in paged spaces. |
| DCHECK(kMaxRegularHeapObjectSize >= |
| (JSArray::kSize + |
| FixedArray::SizeFor(JSArray::kInitialMaxFastElementArray) + |
| AllocationMemento::kSize)); |
| |
| code_range_size_ = code_range_size * MB; |
| |
| configured_ = true; |
| return true; |
| } |
| |
| |
| void Heap::AddToRingBuffer(const char* string) { |
| size_t first_part = |
| Min(strlen(string), kTraceRingBufferSize - ring_buffer_end_); |
| memcpy(trace_ring_buffer_ + ring_buffer_end_, string, first_part); |
| ring_buffer_end_ += first_part; |
| if (first_part < strlen(string)) { |
| ring_buffer_full_ = true; |
| size_t second_part = strlen(string) - first_part; |
| memcpy(trace_ring_buffer_, string + first_part, second_part); |
| ring_buffer_end_ = second_part; |
| } |
| } |
| |
| |
| void Heap::GetFromRingBuffer(char* buffer) { |
| size_t copied = 0; |
| if (ring_buffer_full_) { |
| copied = kTraceRingBufferSize - ring_buffer_end_; |
| memcpy(buffer, trace_ring_buffer_ + ring_buffer_end_, copied); |
| } |
| memcpy(buffer + copied, trace_ring_buffer_, ring_buffer_end_); |
| } |
| |
| |
| bool Heap::ConfigureHeapDefault() { return ConfigureHeap(0, 0, 0, 0); } |
| |
| |
| void Heap::RecordStats(HeapStats* stats, bool take_snapshot) { |
| *stats->start_marker = HeapStats::kStartMarker; |
| *stats->end_marker = HeapStats::kEndMarker; |
| *stats->new_space_size = new_space_->Size(); |
| *stats->new_space_capacity = new_space_->Capacity(); |
| *stats->old_space_size = old_space_->SizeOfObjects(); |
| *stats->old_space_capacity = old_space_->Capacity(); |
| *stats->code_space_size = code_space_->SizeOfObjects(); |
| *stats->code_space_capacity = code_space_->Capacity(); |
| *stats->map_space_size = map_space_->SizeOfObjects(); |
| *stats->map_space_capacity = map_space_->Capacity(); |
| *stats->lo_space_size = lo_space_->Size(); |
| isolate_->global_handles()->RecordStats(stats); |
| *stats->memory_allocator_size = memory_allocator()->Size(); |
| *stats->memory_allocator_capacity = |
| memory_allocator()->Size() + memory_allocator()->Available(); |
| *stats->os_error = base::OS::GetLastError(); |
| *stats->malloced_memory = isolate_->allocator()->GetCurrentMemoryUsage(); |
| *stats->malloced_peak_memory = isolate_->allocator()->GetMaxMemoryUsage(); |
| if (take_snapshot) { |
| HeapIterator iterator(this); |
| for (HeapObject* obj = iterator.next(); obj != NULL; |
| obj = iterator.next()) { |
| InstanceType type = obj->map()->instance_type(); |
| DCHECK(0 <= type && type <= LAST_TYPE); |
| stats->objects_per_type[type]++; |
| stats->size_per_type[type] += obj->Size(); |
| } |
| } |
| if (stats->last_few_messages != NULL) |
| GetFromRingBuffer(stats->last_few_messages); |
| if (stats->js_stacktrace != NULL) { |
| FixedStringAllocator fixed(stats->js_stacktrace, kStacktraceBufferSize - 1); |
| StringStream accumulator(&fixed, StringStream::kPrintObjectConcise); |
| if (gc_state() == Heap::NOT_IN_GC) { |
| isolate()->PrintStack(&accumulator, Isolate::kPrintStackVerbose); |
| } else { |
| accumulator.Add("Cannot get stack trace in GC."); |
| } |
| } |
| } |
| |
| size_t Heap::PromotedSpaceSizeOfObjects() { |
| return old_space_->SizeOfObjects() + code_space_->SizeOfObjects() + |
| map_space_->SizeOfObjects() + lo_space_->SizeOfObjects(); |
| } |
| |
| uint64_t Heap::PromotedExternalMemorySize() { |
| if (external_memory_ <= external_memory_at_last_mark_compact_) return 0; |
| return static_cast<uint64_t>(external_memory_ - |
| external_memory_at_last_mark_compact_); |
| } |
| |
| |
| const double Heap::kMinHeapGrowingFactor = 1.1; |
| const double Heap::kMaxHeapGrowingFactor = 4.0; |
| const double Heap::kMaxHeapGrowingFactorMemoryConstrained = 2.0; |
| const double Heap::kMaxHeapGrowingFactorIdle = 1.5; |
| const double Heap::kConservativeHeapGrowingFactor = 1.3; |
| const double Heap::kTargetMutatorUtilization = 0.97; |
| |
| |
| // Given GC speed in bytes per ms, the allocation throughput in bytes per ms |
| // (mutator speed), this function returns the heap growing factor that will |
| // achieve the kTargetMutatorUtilisation if the GC speed and the mutator speed |
| // remain the same until the next GC. |
| // |
| // For a fixed time-frame T = TM + TG, the mutator utilization is the ratio |
| // TM / (TM + TG), where TM is the time spent in the mutator and TG is the |
| // time spent in the garbage collector. |
| // |
| // Let MU be kTargetMutatorUtilisation, the desired mutator utilization for the |
| // time-frame from the end of the current GC to the end of the next GC. Based |
| // on the MU we can compute the heap growing factor F as |
| // |
| // F = R * (1 - MU) / (R * (1 - MU) - MU), where R = gc_speed / mutator_speed. |
| // |
| // This formula can be derived as follows. |
| // |
| // F = Limit / Live by definition, where the Limit is the allocation limit, |
| // and the Live is size of live objects. |
| // Let’s assume that we already know the Limit. Then: |
| // TG = Limit / gc_speed |
| // TM = (TM + TG) * MU, by definition of MU. |
| // TM = TG * MU / (1 - MU) |
| // TM = Limit * MU / (gc_speed * (1 - MU)) |
| // On the other hand, if the allocation throughput remains constant: |
| // Limit = Live + TM * allocation_throughput = Live + TM * mutator_speed |
| // Solving it for TM, we get |
| // TM = (Limit - Live) / mutator_speed |
| // Combining the two equation for TM: |
| // (Limit - Live) / mutator_speed = Limit * MU / (gc_speed * (1 - MU)) |
| // (Limit - Live) = Limit * MU * mutator_speed / (gc_speed * (1 - MU)) |
| // substitute R = gc_speed / mutator_speed |
| // (Limit - Live) = Limit * MU / (R * (1 - MU)) |
| // substitute F = Limit / Live |
| // F - 1 = F * MU / (R * (1 - MU)) |
| // F - F * MU / (R * (1 - MU)) = 1 |
| // F * (1 - MU / (R * (1 - MU))) = 1 |
| // F * (R * (1 - MU) - MU) / (R * (1 - MU)) = 1 |
| // F = R * (1 - MU) / (R * (1 - MU) - MU) |
| double Heap::HeapGrowingFactor(double gc_speed, double mutator_speed) { |
| if (gc_speed == 0 || mutator_speed == 0) return kMaxHeapGrowingFactor; |
| |
| const double speed_ratio = gc_speed / mutator_speed; |
| const double mu = kTargetMutatorUtilization; |
| |
| const double a = speed_ratio * (1 - mu); |
| const double b = speed_ratio * (1 - mu) - mu; |
| |
| // The factor is a / b, but we need to check for small b first. |
| double factor = |
| (a < b * kMaxHeapGrowingFactor) ? a / b : kMaxHeapGrowingFactor; |
| factor = Min(factor, kMaxHeapGrowingFactor); |
| factor = Max(factor, kMinHeapGrowingFactor); |
| return factor; |
| } |
| |
| size_t Heap::CalculateOldGenerationAllocationLimit(double factor, |
| size_t old_gen_size) { |
| CHECK(factor > 1.0); |
| CHECK(old_gen_size > 0); |
| uint64_t limit = static_cast<uint64_t>(old_gen_size * factor); |
| limit = Max(limit, static_cast<uint64_t>(old_gen_size) + |
| MinimumAllocationLimitGrowingStep()); |
| limit += new_space_->Capacity(); |
| uint64_t halfway_to_the_max = |
| (static_cast<uint64_t>(old_gen_size) + max_old_generation_size_) / 2; |
| return static_cast<size_t>(Min(limit, halfway_to_the_max)); |
| } |
| |
| size_t Heap::MinimumAllocationLimitGrowingStep() { |
| const size_t kRegularAllocationLimitGrowingStep = 8; |
| const size_t kLowMemoryAllocationLimitGrowingStep = 2; |
| size_t limit = (Page::kPageSize > MB ? Page::kPageSize : MB); |
| return limit * (ShouldOptimizeForMemoryUsage() |
| ? kLowMemoryAllocationLimitGrowingStep |
| : kRegularAllocationLimitGrowingStep); |
| } |
| |
| void Heap::SetOldGenerationAllocationLimit(size_t old_gen_size, double gc_speed, |
| double mutator_speed) { |
| double factor = HeapGrowingFactor(gc_speed, mutator_speed); |
| |
| if (FLAG_trace_gc_verbose) { |
| isolate_->PrintWithTimestamp( |
| "Heap growing factor %.1f based on mu=%.3f, speed_ratio=%.f " |
| "(gc=%.f, mutator=%.f)\n", |
| factor, kTargetMutatorUtilization, gc_speed / mutator_speed, gc_speed, |
| mutator_speed); |
| } |
| |
| if (IsMemoryConstrainedDevice()) { |
| factor = Min(factor, kMaxHeapGrowingFactorMemoryConstrained); |
| } |
| |
| if (memory_reducer_->ShouldGrowHeapSlowly() || |
| ShouldOptimizeForMemoryUsage()) { |
| factor = Min(factor, kConservativeHeapGrowingFactor); |
| } |
| |
| if (FLAG_stress_compaction || ShouldReduceMemory()) { |
| factor = kMinHeapGrowingFactor; |
| } |
| |
| if (FLAG_heap_growing_percent > 0) { |
| factor = 1.0 + FLAG_heap_growing_percent / 100.0; |
| } |
| |
| old_generation_allocation_limit_ = |
| CalculateOldGenerationAllocationLimit(factor, old_gen_size); |
| |
| if (FLAG_trace_gc_verbose) { |
| isolate_->PrintWithTimestamp( |
| "Grow: old size: %" PRIuS " KB, new limit: %" PRIuS " KB (%.1f)\n", |
| old_gen_size / KB, old_generation_allocation_limit_ / KB, factor); |
| } |
| } |
| |
| void Heap::DampenOldGenerationAllocationLimit(size_t old_gen_size, |
| double gc_speed, |
| double mutator_speed) { |
| double factor = HeapGrowingFactor(gc_speed, mutator_speed); |
| size_t limit = CalculateOldGenerationAllocationLimit(factor, old_gen_size); |
| if (limit < old_generation_allocation_limit_) { |
| if (FLAG_trace_gc_verbose) { |
| isolate_->PrintWithTimestamp( |
| "Dampen: old size: %" PRIuS " KB, old limit: %" PRIuS |
| " KB, " |
| "new limit: %" PRIuS " KB (%.1f)\n", |
| old_gen_size / KB, old_generation_allocation_limit_ / KB, limit / KB, |
| factor); |
| } |
| old_generation_allocation_limit_ = limit; |
| } |
| } |
| |
| bool Heap::ShouldOptimizeForLoadTime() { |
| return isolate()->rail_mode() == PERFORMANCE_LOAD && |
| !AllocationLimitOvershotByLargeMargin() && |
| MonotonicallyIncreasingTimeInMs() < |
| isolate()->LoadStartTimeMs() + kMaxLoadTimeMs; |
| } |
| |
| // This predicate is called when an old generation space cannot allocated from |
| // the free list and is about to add a new page. Returning false will cause a |
| // major GC. It happens when the old generation allocation limit is reached and |
| // - either we need to optimize for memory usage, |
| // - or the incremental marking is not in progress and we cannot start it. |
| bool Heap::ShouldExpandOldGenerationOnSlowAllocation() { |
| if (always_allocate() || OldGenerationSpaceAvailable() > 0) return true; |
| // We reached the old generation allocation limit. |
| |
| if (ShouldOptimizeForMemoryUsage()) return false; |
| |
| if (ShouldOptimizeForLoadTime()) return true; |
| |
| if (incremental_marking()->NeedsFinalization()) { |
| return !AllocationLimitOvershotByLargeMargin(); |
| } |
| |
| if (incremental_marking()->IsStopped() && |
| IncrementalMarkingLimitReached() == IncrementalMarkingLimit::kNoLimit) { |
| // We cannot start incremental marking. |
| return false; |
| } |
| return true; |
| } |
| |
| // This function returns either kNoLimit, kSoftLimit, or kHardLimit. |
| // The kNoLimit means that either incremental marking is disabled or it is too |
| // early to start incremental marking. |
| // The kSoftLimit means that incremental marking should be started soon. |
| // The kHardLimit means that incremental marking should be started immediately. |
| Heap::IncrementalMarkingLimit Heap::IncrementalMarkingLimitReached() { |
| if (!incremental_marking()->CanBeActivated() || |
| PromotedSpaceSizeOfObjects() <= |
| IncrementalMarking::kActivationThreshold) { |
| // Incremental marking is disabled or it is too early to start. |
| return IncrementalMarkingLimit::kNoLimit; |
| } |
| if ((FLAG_stress_compaction && (gc_count_ & 1) != 0) || |
| HighMemoryPressure()) { |
| // If there is high memory pressure or stress testing is enabled, then |
| // start marking immediately. |
| return IncrementalMarkingLimit::kHardLimit; |
| } |
| size_t old_generation_space_available = OldGenerationSpaceAvailable(); |
| if (old_generation_space_available > new_space_->Capacity()) { |
| return IncrementalMarkingLimit::kNoLimit; |
| } |
| if (ShouldOptimizeForMemoryUsage()) { |
| return IncrementalMarkingLimit::kHardLimit; |
| } |
| if (ShouldOptimizeForLoadTime()) { |
| return IncrementalMarkingLimit::kNoLimit; |
| } |
| if (old_generation_space_available == 0) { |
| return IncrementalMarkingLimit::kHardLimit; |
| } |
| return IncrementalMarkingLimit::kSoftLimit; |
| } |
| |
| void Heap::EnableInlineAllocation() { |
| if (!inline_allocation_disabled_) return; |
| inline_allocation_disabled_ = false; |
| |
| // Update inline allocation limit for new space. |
| new_space()->UpdateInlineAllocationLimit(0); |
| } |
| |
| |
| void Heap::DisableInlineAllocation() { |
| if (inline_allocation_disabled_) return; |
| inline_allocation_disabled_ = true; |
| |
| // Update inline allocation limit for new space. |
| new_space()->UpdateInlineAllocationLimit(0); |
| |
| // Update inline allocation limit for old spaces. |
| PagedSpaces spaces(this); |
| for (PagedSpace* space = spaces.next(); space != NULL; |
| space = spaces.next()) { |
| space->EmptyAllocationInfo(); |
| } |
| } |
| |
| |
| V8_DECLARE_ONCE(initialize_gc_once); |
| |
| static void InitializeGCOnce() { |
| Scavenger::Initialize(); |
| StaticScavengeVisitor::Initialize(); |
| MarkCompactCollector::Initialize(); |
| } |
| |
| |
| bool Heap::SetUp() { |
| #ifdef DEBUG |
| allocation_timeout_ = FLAG_gc_interval; |
| #endif |
| |
| // Initialize heap spaces and initial maps and objects. Whenever something |
| // goes wrong, just return false. The caller should check the results and |
| // call Heap::TearDown() to release allocated memory. |
| // |
| // If the heap is not yet configured (e.g. through the API), configure it. |
| // Configuration is based on the flags new-space-size (really the semispace |
| // size) and old-space-size if set or the initial values of semispace_size_ |
| // and old_generation_size_ otherwise. |
| if (!configured_) { |
| if (!ConfigureHeapDefault()) return false; |
| } |
| |
| base::CallOnce(&initialize_gc_once, &InitializeGCOnce); |
| |
| // Set up memory allocator. |
| memory_allocator_ = new MemoryAllocator(isolate_); |
| if (!memory_allocator_->SetUp(MaxReserved(), MaxExecutableSize(), |
| code_range_size_)) |
| return false; |
| |
| // Initialize store buffer. |
| store_buffer_ = new StoreBuffer(this); |
| |
| // Initialize incremental marking. |
| incremental_marking_ = new IncrementalMarking(this); |
| |
| for (int i = 0; i <= LAST_SPACE; i++) { |
| space_[i] = nullptr; |
| } |
| |
| space_[NEW_SPACE] = new_space_ = new NewSpace(this); |
| if (!new_space_->SetUp(initial_semispace_size_, max_semi_space_size_)) { |
| return false; |
| } |
| new_space_top_after_last_gc_ = new_space()->top(); |
| |
| space_[OLD_SPACE] = old_space_ = |
| new OldSpace(this, OLD_SPACE, NOT_EXECUTABLE); |
| if (!old_space_->SetUp()) return false; |
| |
| space_[CODE_SPACE] = code_space_ = new OldSpace(this, CODE_SPACE, EXECUTABLE); |
| if (!code_space_->SetUp()) return false; |
| |
| space_[MAP_SPACE] = map_space_ = new MapSpace(this, MAP_SPACE); |
| if (!map_space_->SetUp()) return false; |
| |
| // The large object code space may contain code or data. We set the memory |
| // to be non-executable here for safety, but this means we need to enable it |
| // explicitly when allocating large code objects. |
| space_[LO_SPACE] = lo_space_ = new LargeObjectSpace(this, LO_SPACE); |
| if (!lo_space_->SetUp()) return false; |
| |
| // Set up the seed that is used to randomize the string hash function. |
| DCHECK(hash_seed() == 0); |
| if (FLAG_randomize_hashes) { |
| if (FLAG_hash_seed == 0) { |
| int rnd = isolate()->random_number_generator()->NextInt(); |
| set_hash_seed(Smi::FromInt(rnd & Name::kHashBitMask)); |
| } else { |
| set_hash_seed(Smi::FromInt(FLAG_hash_seed)); |
| } |
| } |
| |
| for (int i = 0; i < static_cast<int>(v8::Isolate::kUseCounterFeatureCount); |
| i++) { |
| deferred_counters_[i] = 0; |
| } |
| |
| tracer_ = new GCTracer(this); |
| scavenge_collector_ = new Scavenger(this); |
| mark_compact_collector_ = new MarkCompactCollector(this); |
| gc_idle_time_handler_ = new GCIdleTimeHandler(); |
| memory_reducer_ = new MemoryReducer(this); |
| if (V8_UNLIKELY(FLAG_gc_stats)) { |
| live_object_stats_ = new ObjectStats(this); |
| dead_object_stats_ = new ObjectStats(this); |
| } |
| scavenge_job_ = new ScavengeJob(); |
| local_embedder_heap_tracer_ = new LocalEmbedderHeapTracer(); |
| |
| LOG(isolate_, IntPtrTEvent("heap-capacity", Capacity())); |
| LOG(isolate_, IntPtrTEvent("heap-available", Available())); |
| |
| store_buffer()->SetUp(); |
| |
| mark_compact_collector()->SetUp(); |
| |
| idle_scavenge_observer_ = new IdleScavengeObserver( |
| *this, ScavengeJob::kBytesAllocatedBeforeNextIdleTask); |
| new_space()->AddAllocationObserver(idle_scavenge_observer_); |
| |
| return true; |
| } |
| |
| |
| bool Heap::CreateHeapObjects() { |
| // Create initial maps. |
| if (!CreateInitialMaps()) return false; |
| if (!CreateApiObjects()) return false; |
| |
| // Create initial objects |
| CreateInitialObjects(); |
| CHECK_EQ(0u, gc_count_); |
| |
| set_native_contexts_list(undefined_value()); |
| set_allocation_sites_list(undefined_value()); |
| |
| return true; |
| } |
| |
| |
| void Heap::SetStackLimits() { |
| DCHECK(isolate_ != NULL); |
| DCHECK(isolate_ == isolate()); |
| // On 64 bit machines, pointers are generally out of range of Smis. We write |
| // something that looks like an out of range Smi to the GC. |
| |
| // Set up the special root array entries containing the stack limits. |
| // These are actually addresses, but the tag makes the GC ignore it. |
| roots_[kStackLimitRootIndex] = reinterpret_cast<Object*>( |
| (isolate_->stack_guard()->jslimit() & ~kSmiTagMask) | kSmiTag); |
| roots_[kRealStackLimitRootIndex] = reinterpret_cast<Object*>( |
| (isolate_->stack_guard()->real_jslimit() & ~kSmiTagMask) | kSmiTag); |
| } |
| |
| void Heap::ClearStackLimits() { |
| roots_[kStackLimitRootIndex] = Smi::kZero; |
| roots_[kRealStackLimitRootIndex] = Smi::kZero; |
| } |
| |
| void Heap::PrintAlloctionsHash() { |
| uint32_t hash = StringHasher::GetHashCore(raw_allocations_hash_); |
| PrintF("\n### Allocations = %u, hash = 0x%08x\n", allocations_count(), hash); |
| } |
| |
| |
| void Heap::NotifyDeserializationComplete() { |
| DCHECK_EQ(0, gc_count()); |
| PagedSpaces spaces(this); |
| for (PagedSpace* s = spaces.next(); s != NULL; s = spaces.next()) { |
| if (isolate()->snapshot_available()) s->ShrinkImmortalImmovablePages(); |
| #ifdef DEBUG |
| // All pages right after bootstrapping must be marked as never-evacuate. |
| for (Page* p : *s) { |
| CHECK(p->NeverEvacuate()); |
| } |
| #endif // DEBUG |
| } |
| |
| deserialization_complete_ = true; |
| } |
| |
| void Heap::SetEmbedderHeapTracer(EmbedderHeapTracer* tracer) { |
| DCHECK_EQ(gc_state_, HeapState::NOT_IN_GC); |
| local_embedder_heap_tracer()->SetRemoteTracer(tracer); |
| } |
| |
| void Heap::TracePossibleWrapper(JSObject* js_object) { |
| DCHECK(js_object->WasConstructedFromApiFunction()); |
| if (js_object->GetInternalFieldCount() >= 2 && |
| js_object->GetInternalField(0) && |
| js_object->GetInternalField(0) != undefined_value() && |
| js_object->GetInternalField(1) != undefined_value()) { |
| DCHECK(reinterpret_cast<intptr_t>(js_object->GetInternalField(0)) % 2 == 0); |
| local_embedder_heap_tracer()->AddWrapperToTrace(std::pair<void*, void*>( |
| reinterpret_cast<void*>(js_object->GetInternalField(0)), |
| reinterpret_cast<void*>(js_object->GetInternalField(1)))); |
| } |
| } |
| |
| void Heap::RegisterExternallyReferencedObject(Object** object) { |
| HeapObject* heap_object = HeapObject::cast(*object); |
| DCHECK(Contains(heap_object)); |
| if (FLAG_incremental_marking_wrappers && incremental_marking()->IsMarking()) { |
| IncrementalMarking::MarkGrey(this, heap_object); |
| } else { |
| DCHECK(mark_compact_collector()->in_use()); |
| mark_compact_collector()->MarkObject(heap_object); |
| } |
| } |
| |
| void Heap::TearDown() { |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| |
| UpdateMaximumCommitted(); |
| |
| if (FLAG_print_max_heap_committed) { |
| PrintF("\n"); |
| PrintF("maximum_committed_by_heap=%" PRIuS " ", MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_new_space=%" PRIuS " ", |
| new_space_->MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_old_space=%" PRIuS " ", |
| old_space_->MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_code_space=%" PRIuS " ", |
| code_space_->MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_map_space=%" PRIuS " ", |
| map_space_->MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_lo_space=%" PRIuS " ", |
| lo_space_->MaximumCommittedMemory()); |
| PrintF("\n\n"); |
| } |
| |
| if (FLAG_verify_predictable) { |
| PrintAlloctionsHash(); |
| } |
| |
| new_space()->RemoveAllocationObserver(idle_scavenge_observer_); |
| delete idle_scavenge_observer_; |
| idle_scavenge_observer_ = nullptr; |
| |
| delete scavenge_collector_; |
| scavenge_collector_ = nullptr; |
| |
| if (mark_compact_collector_ != nullptr) { |
| mark_compact_collector_->TearDown(); |
| delete mark_compact_collector_; |
| mark_compact_collector_ = nullptr; |
| } |
| |
| delete incremental_marking_; |
| incremental_marking_ = nullptr; |
| |
| delete gc_idle_time_handler_; |
| gc_idle_time_handler_ = nullptr; |
| |
| if (memory_reducer_ != nullptr) { |
| memory_reducer_->TearDown(); |
| delete memory_reducer_; |
| memory_reducer_ = nullptr; |
| } |
| |
| if (live_object_stats_ != nullptr) { |
| delete live_object_stats_; |
| live_object_stats_ = nullptr; |
| } |
| |
| if (dead_object_stats_ != nullptr) { |
| delete dead_object_stats_; |
| dead_object_stats_ = nullptr; |
| } |
| |
| delete local_embedder_heap_tracer_; |
| local_embedder_heap_tracer_ = nullptr; |
| |
| delete scavenge_job_; |
| scavenge_job_ = nullptr; |
| |
| isolate_->global_handles()->TearDown(); |
| |
| external_string_table_.TearDown(); |
| |
| delete tracer_; |
| tracer_ = nullptr; |
| |
| new_space_->TearDown(); |
| delete new_space_; |
| new_space_ = nullptr; |
| |
| if (old_space_ != NULL) { |
| delete old_space_; |
| old_space_ = NULL; |
| } |
| |
| if (code_space_ != NULL) { |
| delete code_space_; |
| code_space_ = NULL; |
| } |
| |
| if (map_space_ != NULL) { |
| delete map_space_; |
| map_space_ = NULL; |
| } |
| |
| if (lo_space_ != NULL) { |
| lo_space_->TearDown(); |
| delete lo_space_; |
| lo_space_ = NULL; |
| } |
| |
| store_buffer()->TearDown(); |
| |
| memory_allocator()->TearDown(); |
| |
| StrongRootsList* next = NULL; |
| for (StrongRootsList* list = strong_roots_list_; list; list = next) { |
| next = list->next; |
| delete list; |
| } |
| strong_roots_list_ = NULL; |
| |
| delete store_buffer_; |
| store_buffer_ = nullptr; |
| |
| delete memory_allocator_; |
| memory_allocator_ = nullptr; |
| } |
| |
| |
| void Heap::AddGCPrologueCallback(v8::Isolate::GCCallback callback, |
| GCType gc_type, bool pass_isolate) { |
| DCHECK(callback != NULL); |
| GCCallbackPair pair(callback, gc_type, pass_isolate); |
| DCHECK(!gc_prologue_callbacks_.Contains(pair)); |
| return gc_prologue_callbacks_.Add(pair); |
| } |
| |
| |
| void Heap::RemoveGCPrologueCallback(v8::Isolate::GCCallback callback) { |
| DCHECK(callback != NULL); |
| for (int i = 0; i < gc_prologue_callbacks_.length(); ++i) { |
| if (gc_prologue_callbacks_[i].callback == callback) { |
| gc_prologue_callbacks_.Remove(i); |
| return; |
| } |
| } |
| UNREACHABLE(); |
| } |
| |
| |
| void Heap::AddGCEpilogueCallback(v8::Isolate::GCCallback callback, |
| GCType gc_type, bool pass_isolate) { |
| DCHECK(callback != NULL); |
| GCCallbackPair pair(callback, gc_type, pass_isolate); |
| DCHECK(!gc_epilogue_callbacks_.Contains(pair)); |
| return gc_epilogue_callbacks_.Add(pair); |
| } |
| |
| |
| void Heap::RemoveGCEpilogueCallback(v8::Isolate::GCCallback callback) { |
| DCHECK(callback != NULL); |
| for (int i = 0; i < gc_epilogue_callbacks_.length(); ++i) { |
| if (gc_epilogue_callbacks_[i].callback == callback) { |
| gc_epilogue_callbacks_.Remove(i); |
| return; |
| } |
| } |
| UNREACHABLE(); |
| } |
| |
| // TODO(ishell): Find a better place for this. |
| void Heap::AddWeakNewSpaceObjectToCodeDependency(Handle<HeapObject> obj, |
| Handle<WeakCell> code) { |
| DCHECK(InNewSpace(*obj)); |
| DCHECK(!InNewSpace(*code)); |
| Handle<ArrayList> list(weak_new_space_object_to_code_list(), isolate()); |
| list = ArrayList::Add(list, isolate()->factory()->NewWeakCell(obj), code); |
| if (*list != weak_new_space_object_to_code_list()) { |
| set_weak_new_space_object_to_code_list(*list); |
| } |
| } |
| |
| // TODO(ishell): Find a better place for this. |
| void Heap::AddWeakObjectToCodeDependency(Handle<HeapObject> obj, |
| Handle<DependentCode> dep) { |
| DCHECK(!InNewSpace(*obj)); |
| DCHECK(!InNewSpace(*dep)); |
| Handle<WeakHashTable> table(weak_object_to_code_table(), isolate()); |
| table = WeakHashTable::Put(table, obj, dep); |
| if (*table != weak_object_to_code_table()) |
| set_weak_object_to_code_table(*table); |
| DCHECK_EQ(*dep, LookupWeakObjectToCodeDependency(obj)); |
| } |
| |
| |
| DependentCode* Heap::LookupWeakObjectToCodeDependency(Handle<HeapObject> obj) { |
| Object* dep = weak_object_to_code_table()->Lookup(obj); |
| if (dep->IsDependentCode()) return DependentCode::cast(dep); |
| return DependentCode::cast(empty_fixed_array()); |
| } |
| |
| namespace { |
| void CompactWeakFixedArray(Object* object) { |
| if (object->IsWeakFixedArray()) { |
| WeakFixedArray* array = WeakFixedArray::cast(object); |
| array->Compact<WeakFixedArray::NullCallback>(); |
| } |
| } |
| } // anonymous namespace |
| |
| void Heap::CompactWeakFixedArrays() { |
| // Find known WeakFixedArrays and compact them. |
| HeapIterator iterator(this); |
| for (HeapObject* o = iterator.next(); o != NULL; o = iterator.next()) { |
| if (o->IsPrototypeInfo()) { |
| Object* prototype_users = PrototypeInfo::cast(o)->prototype_users(); |
| if (prototype_users->IsWeakFixedArray()) { |
| WeakFixedArray* array = WeakFixedArray::cast(prototype_users); |
| array->Compact<JSObject::PrototypeRegistryCompactionCallback>(); |
| } |
| } |
| } |
| CompactWeakFixedArray(noscript_shared_function_infos()); |
| CompactWeakFixedArray(script_list()); |
| CompactWeakFixedArray(weak_stack_trace_list()); |
| } |
| |
| void Heap::AddRetainedMap(Handle<Map> map) { |
| Handle<WeakCell> cell = Map::WeakCellForMap(map); |
| Handle<ArrayList> array(retained_maps(), isolate()); |
| if (array->IsFull()) { |
| CompactRetainedMaps(*array); |
| } |
| array = ArrayList::Add( |
| array, cell, handle(Smi::FromInt(FLAG_retain_maps_for_n_gc), isolate()), |
| ArrayList::kReloadLengthAfterAllocation); |
| if (*array != retained_maps()) { |
| set_retained_maps(*array); |
| } |
| } |
| |
| |
| void Heap::CompactRetainedMaps(ArrayList* retained_maps) { |
| DCHECK_EQ(retained_maps, this->retained_maps()); |
| int length = retained_maps->Length(); |
| int new_length = 0; |
| int new_number_of_disposed_maps = 0; |
| // This loop compacts the array by removing cleared weak cells. |
| for (int i = 0; i < length; i += 2) { |
| DCHECK(retained_maps->Get(i)->IsWeakCell()); |
| WeakCell* cell = WeakCell::cast(retained_maps->Get(i)); |
| Object* age = retained_maps->Get(i + 1); |
| if (cell->cleared()) continue; |
| if (i != new_length) { |
| retained_maps->Set(new_length, cell); |
| retained_maps->Set(new_length + 1, age); |
| } |
| if (i < number_of_disposed_maps_) { |
| new_number_of_disposed_maps += 2; |
| } |
| new_length += 2; |
| } |
| number_of_disposed_maps_ = new_number_of_disposed_maps; |
| Object* undefined = undefined_value(); |
| for (int i = new_length; i < length; i++) { |
| retained_maps->Clear(i, undefined); |
| } |
| if (new_length != length) retained_maps->SetLength(new_length); |
| } |
| |
| void Heap::FatalProcessOutOfMemory(const char* location, bool is_heap_oom) { |
| v8::internal::V8::FatalProcessOutOfMemory(location, is_heap_oom); |
| } |
| |
| #ifdef DEBUG |
| |
| class PrintHandleVisitor : public ObjectVisitor { |
| public: |
| void VisitPointers(Object** start, Object** end) override { |
| for (Object** p = start; p < end; p++) |
| PrintF(" handle %p to %p\n", reinterpret_cast<void*>(p), |
| reinterpret_cast<void*>(*p)); |
| } |
| }; |
| |
| |
| void Heap::PrintHandles() { |
| PrintF("Handles:\n"); |
| PrintHandleVisitor v; |
| isolate_->handle_scope_implementer()->Iterate(&v); |
| } |
| |
| #endif |
| |
| class CheckHandleCountVisitor : public ObjectVisitor { |
| public: |
| CheckHandleCountVisitor() : handle_count_(0) {} |
| ~CheckHandleCountVisitor() override { |
| CHECK(handle_count_ < HandleScope::kCheckHandleThreshold); |
| } |
| void VisitPointers(Object** start, Object** end) override { |
| handle_count_ += end - start; |
| } |
| |
| private: |
| ptrdiff_t handle_count_; |
| }; |
| |
| |
| void Heap::CheckHandleCount() { |
| CheckHandleCountVisitor v; |
| isolate_->handle_scope_implementer()->Iterate(&v); |
| } |
| |
| void Heap::ClearRecordedSlot(HeapObject* object, Object** slot) { |
| if (!InNewSpace(object)) { |
| Address slot_addr = reinterpret_cast<Address>(slot); |
| Page* page = Page::FromAddress(slot_addr); |
| DCHECK_EQ(page->owner()->identity(), OLD_SPACE); |
| store_buffer()->DeleteEntry(slot_addr); |
| RememberedSet<OLD_TO_OLD>::Remove(page, slot_addr); |
| } |
| } |
| |
| bool Heap::HasRecordedSlot(HeapObject* object, Object** slot) { |
| if (InNewSpace(object)) { |
| return false; |
| } |
| Address slot_addr = reinterpret_cast<Address>(slot); |
| Page* page = Page::FromAddress(slot_addr); |
| DCHECK_EQ(page->owner()->identity(), OLD_SPACE); |
| store_buffer()->MoveAllEntriesToRememberedSet(); |
| return RememberedSet<OLD_TO_NEW>::Contains(page, slot_addr) || |
| RememberedSet<OLD_TO_OLD>::Contains(page, slot_addr); |
| } |
| |
| void Heap::ClearRecordedSlotRange(Address start, Address end) { |
| Page* page = Page::FromAddress(start); |
| if (!page->InNewSpace()) { |
| DCHECK_EQ(page->owner()->identity(), OLD_SPACE); |
| store_buffer()->DeleteEntry(start, end); |
| RememberedSet<OLD_TO_OLD>::RemoveRange(page, start, end, |
| SlotSet::FREE_EMPTY_BUCKETS); |
| } |
| } |
| |
| void Heap::RecordWriteIntoCodeSlow(Code* host, RelocInfo* rinfo, |
| Object* value) { |
| DCHECK(InNewSpace(value)); |
| Page* source_page = Page::FromAddress(reinterpret_cast<Address>(host)); |
| RelocInfo::Mode rmode = rinfo->rmode(); |
| Address addr = rinfo->pc(); |
| SlotType slot_type = SlotTypeForRelocInfoMode(rmode); |
| if (rinfo->IsInConstantPool()) { |
| addr = rinfo->constant_pool_entry_address(); |
| if (RelocInfo::IsCodeTarget(rmode)) { |
| slot_type = CODE_ENTRY_SLOT; |
| } else { |
| DCHECK(RelocInfo::IsEmbeddedObject(rmode)); |
| slot_type = OBJECT_SLOT; |
| } |
| } |
| RememberedSet<OLD_TO_NEW>::InsertTyped( |
| source_page, reinterpret_cast<Address>(host), slot_type, addr); |
| } |
| |
| void Heap::RecordWritesIntoCode(Code* code) { |
| for (RelocIterator it(code, RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT)); |
| !it.done(); it.next()) { |
| RecordWriteIntoCode(code, it.rinfo(), it.rinfo()->target_object()); |
| } |
| } |
| |
| Space* AllSpaces::next() { |
| switch (counter_++) { |
| case NEW_SPACE: |
| return heap_->new_space(); |
| case OLD_SPACE: |
| return heap_->old_space(); |
| case CODE_SPACE: |
| return heap_->code_space(); |
| case MAP_SPACE: |
| return heap_->map_space(); |
| case LO_SPACE: |
| return heap_->lo_space(); |
| default: |
| return NULL; |
| } |
| } |
| |
| PagedSpace* PagedSpaces::next() { |
| switch (counter_++) { |
| case OLD_SPACE: |
| return heap_->old_space(); |
| case CODE_SPACE: |
| return heap_->code_space(); |
| case MAP_SPACE: |
| return heap_->map_space(); |
| default: |
| return NULL; |
| } |
| } |
| |
| |
| OldSpace* OldSpaces::next() { |
| switch (counter_++) { |
| case OLD_SPACE: |
| return heap_->old_space(); |
| case CODE_SPACE: |
| return heap_->code_space(); |
| default: |
| return NULL; |
| } |
| } |
| |
| SpaceIterator::SpaceIterator(Heap* heap) |
| : heap_(heap), current_space_(FIRST_SPACE - 1) {} |
| |
| SpaceIterator::~SpaceIterator() { |
| } |
| |
| |
| bool SpaceIterator::has_next() { |
| // Iterate until no more spaces. |
| return current_space_ != LAST_SPACE; |
| } |
| |
| Space* SpaceIterator::next() { |
| DCHECK(has_next()); |
| return heap_->space(++current_space_); |
| } |
| |
| |
| class HeapObjectsFilter { |
| public: |
| virtual ~HeapObjectsFilter() {} |
| virtual bool SkipObject(HeapObject* object) = 0; |
| }; |
| |
| |
| class UnreachableObjectsFilter : public HeapObjectsFilter { |
| public: |
| explicit UnreachableObjectsFilter(Heap* heap) : heap_(heap) { |
| MarkReachableObjects(); |
| } |
| |
| ~UnreachableObjectsFilter() { |
| heap_->mark_compact_collector()->ClearMarkbits(); |
| } |
| |
| bool SkipObject(HeapObject* object) { |
| if (object->IsFiller()) return true; |
| return ObjectMarking::IsWhite(object); |
| } |
| |
| private: |
| class MarkingVisitor : public ObjectVisitor { |
| public: |
| MarkingVisitor() : marking_stack_(10) {} |
| |
| void VisitPointers(Object** start, Object** end) override { |
| for (Object** p = start; p < end; p++) { |
| if (!(*p)->IsHeapObject()) continue; |
| HeapObject* obj = HeapObject::cast(*p); |
| // Use Marking instead of ObjectMarking to avoid adjusting live bytes |
| // counter. |
| MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj); |
| if (Marking::IsWhite(mark_bit)) { |
| Marking::WhiteToBlack(mark_bit); |
| marking_stack_.Add(obj); |
| } |
| } |
| } |
| |
| void TransitiveClosure() { |
| while (!marking_stack_.is_empty()) { |
| HeapObject* obj = marking_stack_.RemoveLast(); |
| obj->Iterate(this); |
| } |
| } |
| |
| private: |
| List<HeapObject*> marking_stack_; |
| }; |
| |
| void MarkReachableObjects() { |
| MarkingVisitor visitor; |
| heap_->IterateRoots(&visitor, VISIT_ALL); |
| visitor.TransitiveClosure(); |
| } |
| |
| Heap* heap_; |
| DisallowHeapAllocation no_allocation_; |
| }; |
| |
| HeapIterator::HeapIterator(Heap* heap, |
| HeapIterator::HeapObjectsFiltering filtering) |
| : no_heap_allocation_(), |
| heap_(heap), |
| filtering_(filtering), |
| filter_(nullptr), |
| space_iterator_(nullptr), |
| object_iterator_(nullptr) { |
| heap_->MakeHeapIterable(); |
| heap_->heap_iterator_start(); |
| // Start the iteration. |
| space_iterator_ = new SpaceIterator(heap_); |
| switch (filtering_) { |
| case kFilterUnreachable: |
| filter_ = new UnreachableObjectsFilter(heap_); |
| break; |
| default: |
| break; |
| } |
| object_iterator_ = space_iterator_->next()->GetObjectIterator(); |
| } |
| |
| |
| HeapIterator::~HeapIterator() { |
| heap_->heap_iterator_end(); |
| #ifdef DEBUG |
| // Assert that in filtering mode we have iterated through all |
| // objects. Otherwise, heap will be left in an inconsistent state. |
| if (filtering_ != kNoFiltering) { |
| DCHECK(object_iterator_ == nullptr); |
| } |
| #endif |
| delete space_iterator_; |
| delete filter_; |
| } |
| |
| |
| HeapObject* HeapIterator::next() { |
| if (filter_ == nullptr) return NextObject(); |
| |
| HeapObject* obj = NextObject(); |
| while ((obj != nullptr) && (filter_->SkipObject(obj))) obj = NextObject(); |
| return obj; |
| } |
| |
| |
| HeapObject* HeapIterator::NextObject() { |
| // No iterator means we are done. |
| if (object_iterator_.get() == nullptr) return nullptr; |
| |
| if (HeapObject* obj = object_iterator_.get()->Next()) { |
| // If the current iterator has more objects we are fine. |
| return obj; |
| } else { |
| // Go though the spaces looking for one that has objects. |
| while (space_iterator_->has_next()) { |
| object_iterator_ = space_iterator_->next()->GetObjectIterator(); |
| if (HeapObject* obj = object_iterator_.get()->Next()) { |
| return obj; |
| } |
| } |
| } |
| // Done with the last space. |
| object_iterator_.reset(nullptr); |
| return nullptr; |
| } |
| |
| |
| #ifdef DEBUG |
| |
| Object* const PathTracer::kAnyGlobalObject = NULL; |
| |
| class PathTracer::MarkVisitor : public ObjectVisitor { |
| public: |
| explicit MarkVisitor(PathTracer* tracer) : tracer_(tracer) {} |
| |
| void VisitPointers(Object** start, Object** end) override { |
| // Scan all HeapObject pointers in [start, end) |
| for (Object** p = start; !tracer_->found() && (p < end); p++) { |
| if ((*p)->IsHeapObject()) tracer_->MarkRecursively(p, this); |
| } |
| } |
| |
| private: |
| PathTracer* tracer_; |
| }; |
| |
| |
| class PathTracer::UnmarkVisitor : public ObjectVisitor { |
| public: |
| explicit UnmarkVisitor(PathTracer* tracer) : tracer_(tracer) {} |
| |
| void VisitPointers(Object** start, Object** end) override { |
| // Scan all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) tracer_->UnmarkRecursively(p, this); |
| } |
| } |
| |
| private: |
| PathTracer* tracer_; |
| }; |
| |
| |
| void PathTracer::VisitPointers(Object** start, Object** end) { |
| bool done = ((what_to_find_ == FIND_FIRST) && found_target_); |
| // Visit all HeapObject pointers in [start, end) |
| for (Object** p = start; !done && (p < end); p++) { |
| if ((*p)->IsHeapObject()) { |
| TracePathFrom(p); |
| done = ((what_to_find_ == FIND_FIRST) && found_target_); |
| } |
| } |
| } |
| |
| |
| void PathTracer::Reset() { |
| found_target_ = false; |
| object_stack_.Clear(); |
| } |
| |
| |
| void PathTracer::TracePathFrom(Object** root) { |
| DCHECK((search_target_ == kAnyGlobalObject) || |
| search_target_->IsHeapObject()); |
| found_target_in_trace_ = false; |
| Reset(); |
| |
| MarkVisitor mark_visitor(this); |
| MarkRecursively(root, &mark_visitor); |
| |
| UnmarkVisitor unmark_visitor(this); |
| UnmarkRecursively(root, &unmark_visitor); |
| |
| ProcessResults(); |
| } |
| |
| |
| static bool SafeIsNativeContext(HeapObject* obj) { |
| return obj->map() == obj->GetHeap()->root(Heap::kNativeContextMapRootIndex); |
| } |
| |
| |
| void PathTracer::MarkRecursively(Object** p, MarkVisitor* mark_visitor) { |
| if (!(*p)->IsHeapObject()) return; |
| |
| HeapObject* obj = HeapObject::cast(*p); |
| |
| MapWord map_word = obj->map_word(); |
| if (!map_word.ToMap()->IsHeapObject()) return; // visited before |
| |
| if (found_target_in_trace_) return; // stop if target found |
| object_stack_.Add(obj); |
| if (((search_target_ == kAnyGlobalObject) && obj->IsJSGlobalObject()) || |
| (obj == search_target_)) { |
| found_target_in_trace_ = true; |
| found_target_ = true; |
| return; |
| } |
| |
| bool is_native_context = SafeIsNativeContext(obj); |
| |
| // not visited yet |
| Map* map = Map::cast(map_word.ToMap()); |
| |
| MapWord marked_map_word = |
| MapWord::FromRawValue(obj->map_word().ToRawValue() + kMarkTag); |
| obj->set_map_word(marked_map_word); |
| |
| // Scan the object body. |
| if (is_native_context && (visit_mode_ == VISIT_ONLY_STRONG)) { |
| // This is specialized to scan Context's properly. |
| Object** start = |
| reinterpret_cast<Object**>(obj->address() + Context::kHeaderSize); |
| Object** end = |
| reinterpret_cast<Object**>(obj->address() + Context::kHeaderSize + |
| Context::FIRST_WEAK_SLOT * kPointerSize); |
| mark_visitor->VisitPointers(start, end); |
| } else { |
| obj->IterateBody(map->instance_type(), obj->SizeFromMap(map), mark_visitor); |
| } |
| |
| // Scan the map after the body because the body is a lot more interesting |
| // when doing leak detection. |
| MarkRecursively(reinterpret_cast<Object**>(&map), mark_visitor); |
| |
| if (!found_target_in_trace_) { // don't pop if found the target |
| object_stack_.RemoveLast(); |
| } |
| } |
| |
| |
| void PathTracer::UnmarkRecursively(Object** p, UnmarkVisitor* unmark_visitor) { |
| if (!(*p)->IsHeapObject()) return; |
| |
| HeapObject* obj = HeapObject::cast(*p); |
| |
| MapWord map_word = obj->map_word(); |
| if (map_word.ToMap()->IsHeapObject()) return; // unmarked already |
| |
| MapWord unmarked_map_word = |
| MapWord::FromRawValue(map_word.ToRawValue() - kMarkTag); |
| obj->set_map_word(unmarked_map_word); |
| |
| Map* map = Map::cast(unmarked_map_word.ToMap()); |
| |
| UnmarkRecursively(reinterpret_cast<Object**>(&map), unmark_visitor); |
| |
| obj->IterateBody(map->instance_type(), obj->SizeFromMap(map), unmark_visitor); |
| } |
| |
| |
| void PathTracer::ProcessResults() { |
| if (found_target_) { |
| OFStream os(stdout); |
| os << "=====================================\n" |
| << "==== Path to object ====\n" |
| << "=====================================\n\n"; |
| |
| DCHECK(!object_stack_.is_empty()); |
| for (int i = 0; i < object_stack_.length(); i++) { |
| if (i > 0) os << "\n |\n |\n V\n\n"; |
| object_stack_[i]->Print(os); |
| } |
| os << "=====================================\n"; |
| } |
| } |
| |
| |
| // Triggers a depth-first traversal of reachable objects from one |
| // given root object and finds a path to a specific heap object and |
| // prints it. |
| void Heap::TracePathToObjectFrom(Object* target, Object* root) { |
| PathTracer tracer(target, PathTracer::FIND_ALL, VISIT_ALL); |
| tracer.VisitPointer(&root); |
| } |
| |
| |
| // Triggers a depth-first traversal of reachable objects from roots |
| // and finds a path to a specific heap object and prints it. |
| void Heap::TracePathToObject(Object* target) { |
| PathTracer tracer(target, PathTracer::FIND_ALL, VISIT_ALL); |
| IterateRoots(&tracer, VISIT_ONLY_STRONG); |
| } |
| |
| |
| // Triggers a depth-first traversal of reachable objects from roots |
| // and finds a path to any global object and prints it. Useful for |
| // determining the source for leaks of global objects. |
| void Heap::TracePathToGlobal() { |
| PathTracer tracer(PathTracer::kAnyGlobalObject, PathTracer::FIND_ALL, |
| VISIT_ALL); |
| IterateRoots(&tracer, VISIT_ONLY_STRONG); |
| } |
| #endif |
| |
| void Heap::UpdateTotalGCTime(double duration) { |
| if (FLAG_trace_gc_verbose) { |
| total_gc_time_ms_ += duration; |
| } |
| } |
| |
| void Heap::ExternalStringTable::CleanUpNewSpaceStrings() { |
| int last = 0; |
| Isolate* isolate = heap_->isolate(); |
| for (int i = 0; i < new_space_strings_.length(); ++i) { |
| Object* o = new_space_strings_[i]; |
| if (o->IsTheHole(isolate)) { |
| continue; |
| } |
| if (o->IsThinString()) { |
| o = ThinString::cast(o)->actual(); |
| if (!o->IsExternalString()) continue; |
| } |
| DCHECK(o->IsExternalString()); |
| if (heap_->InNewSpace(o)) { |
| new_space_strings_[last++] = o; |
| } else { |
| old_space_strings_.Add(o); |
| } |
| } |
| new_space_strings_.Rewind(last); |
| new_space_strings_.Trim(); |
| } |
| |
| void Heap::ExternalStringTable::CleanUpAll() { |
| CleanUpNewSpaceStrings(); |
| int last = 0; |
| Isolate* isolate = heap_->isolate(); |
| for (int i = 0; i < old_space_strings_.length(); ++i) { |
| Object* o = old_space_strings_[i]; |
| if (o->IsTheHole(isolate)) { |
| continue; |
| } |
| if (o->IsThinString()) { |
| o = ThinString::cast(o)->actual(); |
| if (!o->IsExternalString()) continue; |
| } |
| DCHECK(o->IsExternalString()); |
| DCHECK(!heap_->InNewSpace(o)); |
| old_space_strings_[last++] = o; |
| } |
| old_space_strings_.Rewind(last); |
| old_space_strings_.Trim(); |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| } |
| |
| void Heap::ExternalStringTable::TearDown() { |
| for (int i = 0; i < new_space_strings_.length(); ++i) { |
| Object* o = new_space_strings_[i]; |
| if (o->IsThinString()) { |
| o = ThinString::cast(o)->actual(); |
| if (!o->IsExternalString()) continue; |
| } |
| heap_->FinalizeExternalString(ExternalString::cast(o)); |
| } |
| new_space_strings_.Free(); |
| for (int i = 0; i < old_space_strings_.length(); ++i) { |
| Object* o = old_space_strings_[i]; |
| if (o->IsThinString()) { |
| o = ThinString::cast(o)->actual(); |
| if (!o->IsExternalString()) continue; |
| } |
| heap_->FinalizeExternalString(ExternalString::cast(o)); |
| } |
| old_space_strings_.Free(); |
| } |
| |
| |
| void Heap::RememberUnmappedPage(Address page, bool compacted) { |
| uintptr_t p = reinterpret_cast<uintptr_t>(page); |
| // Tag the page pointer to make it findable in the dump file. |
| if (compacted) { |
| p ^= 0xc1ead & (Page::kPageSize - 1); // Cleared. |
| } else { |
| p ^= 0x1d1ed & (Page::kPageSize - 1); // I died. |
| } |
| remembered_unmapped_pages_[remembered_unmapped_pages_index_] = |
| reinterpret_cast<Address>(p); |
| remembered_unmapped_pages_index_++; |
| remembered_unmapped_pages_index_ %= kRememberedUnmappedPages; |
| } |
| |
| |
| void Heap::RegisterStrongRoots(Object** start, Object** end) { |
| StrongRootsList* list = new StrongRootsList(); |
| list->next = strong_roots_list_; |
| list->start = start; |
| list->end = end; |
| strong_roots_list_ = list; |
| } |
| |
| |
| void Heap::UnregisterStrongRoots(Object** start) { |
| StrongRootsList* prev = NULL; |
| StrongRootsList* list = strong_roots_list_; |
| while (list != nullptr) { |
| StrongRootsList* next = list->next; |
| if (list->start == start) { |
| if (prev) { |
| prev->next = next; |
| } else { |
| strong_roots_list_ = next; |
| } |
| delete list; |
| } else { |
| prev = list; |
| } |
| list = next; |
| } |
| } |
| |
| |
| size_t Heap::NumberOfTrackedHeapObjectTypes() { |
| return ObjectStats::OBJECT_STATS_COUNT; |
| } |
| |
| |
| size_t Heap::ObjectCountAtLastGC(size_t index) { |
| if (live_object_stats_ == nullptr || index >= ObjectStats::OBJECT_STATS_COUNT) |
| return 0; |
| return live_object_stats_->object_count_last_gc(index); |
| } |
| |
| |
| size_t Heap::ObjectSizeAtLastGC(size_t index) { |
| if (live_object_stats_ == nullptr || index >= ObjectStats::OBJECT_STATS_COUNT) |
| return 0; |
| return live_object_stats_->object_size_last_gc(index); |
| } |
| |
| |
| bool Heap::GetObjectTypeName(size_t index, const char** object_type, |
| const char** object_sub_type) { |
| if (index >= ObjectStats::OBJECT_STATS_COUNT) return false; |
| |
| switch (static_cast<int>(index)) { |
| #define COMPARE_AND_RETURN_NAME(name) \ |
| case name: \ |
| *object_type = #name; \ |
| *object_sub_type = ""; \ |
| return true; |
| INSTANCE_TYPE_LIST(COMPARE_AND_RETURN_NAME) |
| #undef COMPARE_AND_RETURN_NAME |
| #define COMPARE_AND_RETURN_NAME(name) \ |
| case ObjectStats::FIRST_CODE_KIND_SUB_TYPE + Code::name: \ |
| *object_type = "CODE_TYPE"; \ |
| *object_sub_type = "CODE_KIND/" #name; \ |
| return true; |
| CODE_KIND_LIST(COMPARE_AND_RETURN_NAME) |
| #undef COMPARE_AND_RETURN_NAME |
| #define COMPARE_AND_RETURN_NAME(name) \ |
| case ObjectStats::FIRST_FIXED_ARRAY_SUB_TYPE + name: \ |
| *object_type = "FIXED_ARRAY_TYPE"; \ |
| *object_sub_type = #name; \ |
| return true; |
| FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(COMPARE_AND_RETURN_NAME) |
| #undef COMPARE_AND_RETURN_NAME |
| #define COMPARE_AND_RETURN_NAME(name) \ |
| case ObjectStats::FIRST_CODE_AGE_SUB_TYPE + Code::k##name##CodeAge - \ |
| Code::kFirstCodeAge: \ |
| *object_type = "CODE_TYPE"; \ |
| *object_sub_type = "CODE_AGE/" #name; \ |
| return true; |
| CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME) |
| #undef COMPARE_AND_RETURN_NAME |
| } |
| return false; |
| } |
| |
| |
| // static |
| int Heap::GetStaticVisitorIdForMap(Map* map) { |
| return StaticVisitorBase::GetVisitorId(map); |
| } |
| |
| } // namespace internal |
| } // namespace v8 |