| // 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/scopeinfo.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/conversions.h" |
| #include "src/debug/debug.h" |
| #include "src/deoptimizer.h" |
| #include "src/global-handles.h" |
| #include "src/heap/array-buffer-tracker.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/profiler/cpu-profiler.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/type-feedback-vector.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() |
| : amount_of_external_allocated_memory_(0), |
| amount_of_external_allocated_memory_at_last_global_gc_(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_(Page::kPageSize), |
| max_old_generation_size_(700ul * (kPointerSize / 4) * MB), |
| 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), |
| contexts_disposed_(0), |
| number_of_disposed_maps_(0), |
| global_ic_age_(0), |
| new_space_(this), |
| 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_), |
| old_gen_exhausted_(false), |
| optimize_for_memory_usage_(false), |
| inline_allocation_disabled_(false), |
| total_regexp_code_generated_(0), |
| tracer_(nullptr), |
| high_survival_rate_period_length_(0), |
| 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), |
| max_gc_pause_(0.0), |
| total_gc_time_ms_(0.0), |
| max_alive_after_gc_(0), |
| min_in_mutator_(kMaxInt), |
| marking_time_(0.0), |
| sweeping_time_(0.0), |
| last_idle_notification_time_(0.0), |
| last_gc_time_(0.0), |
| scavenge_collector_(nullptr), |
| mark_compact_collector_(nullptr), |
| memory_allocator_(nullptr), |
| store_buffer_(this), |
| incremental_marking_(nullptr), |
| gc_idle_time_handler_(nullptr), |
| memory_reducer_(nullptr), |
| object_stats_(nullptr), |
| scavenge_job_(nullptr), |
| idle_scavenge_observer_(nullptr), |
| full_codegen_bytes_generated_(0), |
| crankshaft_codegen_bytes_generated_(0), |
| new_space_allocation_counter_(0), |
| old_generation_allocation_counter_(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), |
| array_buffer_tracker_(NULL), |
| heap_iterator_depth_(0), |
| force_oom_(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::FromInt(0)); |
| set_encountered_weak_collections(Smi::FromInt(0)); |
| set_encountered_weak_cells(Smi::FromInt(0)); |
| set_encountered_transition_arrays(Smi::FromInt(0)); |
| // 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); |
| } |
| |
| |
| intptr_t Heap::Capacity() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return new_space_.Capacity() + OldGenerationCapacity(); |
| } |
| |
| intptr_t Heap::OldGenerationCapacity() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return old_space_->Capacity() + code_space_->Capacity() + |
| map_space_->Capacity() + lo_space_->SizeOfObjects(); |
| } |
| |
| |
| intptr_t Heap::CommittedOldGenerationMemory() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return old_space_->CommittedMemory() + code_space_->CommittedMemory() + |
| map_space_->CommittedMemory() + lo_space_->Size(); |
| } |
| |
| |
| intptr_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(); |
| } |
| |
| |
| intptr_t Heap::CommittedMemoryExecutable() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return memory_allocator()->SizeExecutable(); |
| } |
| |
| |
| void Heap::UpdateMaximumCommitted() { |
| if (!HasBeenSetUp()) return; |
| |
| intptr_t current_committed_memory = CommittedMemory(); |
| if (current_committed_memory > maximum_committed_) { |
| maximum_committed_ = current_committed_memory; |
| } |
| } |
| |
| |
| intptr_t Heap::Available() { |
| if (!HasBeenSetUp()) return 0; |
| |
| intptr_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; |
| } |
| |
| // Is enough data promoted to justify a global GC? |
| if (OldGenerationAllocationLimitReached()) { |
| isolate_->counters()->gc_compactor_caused_by_promoted_data()->Increment(); |
| *reason = "promotion limit reached"; |
| return MARK_COMPACTOR; |
| } |
| |
| // Have allocation in OLD and LO failed? |
| if (old_gen_exhausted_) { |
| isolate_->counters() |
| ->gc_compactor_caused_by_oldspace_exhaustion() |
| ->Increment(); |
| *reason = "old generations exhausted"; |
| 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 SCAVENGER; |
| } |
| |
| |
| // 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" V8PRIdPTR |
| " KB, available: %6" V8PRIdPTR " KB\n", |
| memory_allocator()->Size() / KB, |
| memory_allocator()->Available() / KB); |
| PrintIsolate(isolate_, "New space, used: %6" V8PRIdPTR |
| " KB" |
| ", available: %6" V8PRIdPTR |
| " KB" |
| ", committed: %6" V8PRIdPTR " KB\n", |
| new_space_.Size() / KB, new_space_.Available() / KB, |
| new_space_.CommittedMemory() / KB); |
| PrintIsolate(isolate_, "Old space, used: %6" V8PRIdPTR |
| " KB" |
| ", available: %6" V8PRIdPTR |
| " KB" |
| ", committed: %6" V8PRIdPTR " KB\n", |
| old_space_->SizeOfObjects() / KB, old_space_->Available() / KB, |
| old_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "Code space, used: %6" V8PRIdPTR |
| " KB" |
| ", available: %6" V8PRIdPTR |
| " KB" |
| ", committed: %6" V8PRIdPTR " KB\n", |
| code_space_->SizeOfObjects() / KB, code_space_->Available() / KB, |
| code_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "Map space, used: %6" V8PRIdPTR |
| " KB" |
| ", available: %6" V8PRIdPTR |
| " KB" |
| ", committed: %6" V8PRIdPTR " KB\n", |
| map_space_->SizeOfObjects() / KB, map_space_->Available() / KB, |
| map_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "Large object space, used: %6" V8PRIdPTR |
| " KB" |
| ", available: %6" V8PRIdPTR |
| " KB" |
| ", committed: %6" V8PRIdPTR " KB\n", |
| lo_space_->SizeOfObjects() / KB, lo_space_->Available() / KB, |
| lo_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, "All spaces, used: %6" V8PRIdPTR |
| " KB" |
| ", available: %6" V8PRIdPTR |
| " KB" |
| ", committed: %6" V8PRIdPTR " KB\n", |
| this->SizeOfObjects() / KB, this->Available() / KB, |
| this->CommittedMemory() / KB); |
| PrintIsolate( |
| isolate_, "External memory reported: %6" V8PRIdPTR " KB\n", |
| static_cast<intptr_t>(amount_of_external_allocated_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]++; |
| } |
| |
| |
| 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(); |
| store_buffer()->MoveEntriesToRememberedSet(); |
| } |
| |
| |
| intptr_t Heap::SizeOfObjects() { |
| intptr_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 HashMap& local_pretenuring_feedback) { |
| AllocationSite* site = nullptr; |
| for (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::PretenuringScope { |
| public: |
| explicit PretenuringScope(Heap* heap) : heap_(heap) { |
| heap_->global_pretenuring_feedback_ = |
| new HashMap(HashMap::PointersMatch, 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 (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 (full_codegen_bytes_generated_ + crankshaft_codegen_bytes_generated_ > 0) { |
| isolate_->counters()->codegen_fraction_crankshaft()->AddSample( |
| static_cast<int>((crankshaft_codegen_bytes_generated_ * 100.0) / |
| (crankshaft_codegen_bytes_generated_ + |
| full_codegen_bytes_generated_))); |
| } |
| |
| 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::FromInt(0)); |
| } |
| |
| |
| 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_, "GC interrupt", |
| 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("GC interrupt: finalize incremental marking"); |
| } |
| } |
| |
| |
| void Heap::ScheduleIdleScavengeIfNeeded(int bytes_allocated) { |
| scavenge_job_->ScheduleIdleTaskIfNeeded(this, bytes_allocated); |
| } |
| |
| |
| void Heap::FinalizeIncrementalMarking(const char* gc_reason) { |
| if (FLAG_trace_incremental_marking) { |
| PrintF("[IncrementalMarking] (%s).\n", 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 (collector == SCAVENGER) { |
| 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, const char* 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(const char* 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 (isolate()->concurrent_recompilation_enabled()) { |
| // The optimizing compiler may be unnecessarily holding on to memory. |
| DisallowHeapAllocation no_recursive_gc; |
| isolate()->optimizing_compile_dispatcher()->Flush(); |
| } |
| 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(const char* gc_reason) { |
| if (incremental_marking()->IsStopped()) { |
| if (incremental_marking()->CanBeActivated()) { |
| StartIncrementalMarking( |
| i::Heap::kNoGCFlags, |
| kGCCallbackFlagSynchronousPhantomCallbackProcessing, gc_reason); |
| } else { |
| CollectAllGarbage(i::Heap::kNoGCFlags, gc_reason, |
| kGCCallbackFlagSynchronousPhantomCallbackProcessing); |
| } |
| } else { |
| // Incremental marking is turned on an has already been started. |
| |
| // TODO(mlippautz): Compute the time slice for incremental marking based on |
| // memory pressure. |
| double deadline = MonotonicallyIncreasingTimeInMs() + |
| FLAG_external_allocation_limit_incremental_time; |
| incremental_marking()->AdvanceIncrementalMarking( |
| deadline, |
| IncrementalMarking::StepActions(IncrementalMarking::GC_VIA_STACK_GUARD, |
| IncrementalMarking::FORCE_MARKING, |
| IncrementalMarking::FORCE_COMPLETION)); |
| } |
| } |
| |
| |
| 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, const char* 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_); |
| |
| #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 (collector == SCAVENGER && !incremental_marking()->IsStopped()) { |
| if (FLAG_trace_incremental_marking) { |
| PrintF("[IncrementalMarking] Scavenge during marking.\n"); |
| } |
| } |
| |
| if (collector == MARK_COMPACTOR && !ShouldFinalizeIncrementalMarking() && |
| !ShouldAbortIncrementalMarking() && !incremental_marking()->IsStopped() && |
| !incremental_marking()->should_hurry() && FLAG_incremental_marking && |
| OldGenerationAllocationLimitReached()) { |
| if (!incremental_marking()->IsComplete() && |
| !mark_compact_collector()->marking_deque_.IsEmpty() && |
| !FLAG_gc_global) { |
| if (FLAG_trace_incremental_marking) { |
| PrintF("[IncrementalMarking] Delaying MarkSweep.\n"); |
| } |
| collector = SCAVENGER; |
| collector_reason = "incremental marking delaying mark-sweep"; |
| } |
| } |
| |
| bool next_gc_likely_to_collect_more = false; |
| intptr_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) { |
| intptr_t committed_memory_after = CommittedOldGenerationMemory(); |
| intptr_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); |
| 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. |
| if (!ShouldAbortIncrementalMarking() && incremental_marking()->IsStopped() && |
| incremental_marking()->ShouldActivateEvenWithoutIdleNotification()) { |
| StartIncrementalMarking(kNoGCFlags, kNoGCCallbackFlags, "GC epilogue"); |
| } |
| |
| 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(); |
| } |
| AgeInlineCaches(); |
| number_of_disposed_maps_ = retained_maps()->Length(); |
| tracer()->AddContextDisposalTime(MonotonicallyIncreasingTimeInMs()); |
| return ++contexts_disposed_; |
| } |
| |
| |
| void Heap::StartIncrementalMarking(int gc_flags, |
| const GCCallbackFlags gc_callback_flags, |
| const char* reason) { |
| DCHECK(incremental_marking()->IsStopped()); |
| set_current_gc_flags(gc_flags); |
| current_gc_callback_flags_ = gc_callback_flags; |
| incremental_marking()->Start(reason); |
| } |
| |
| |
| void Heap::StartIdleIncrementalMarking() { |
| gc_idle_time_handler_->ResetNoProgressCounter(); |
| StartIncrementalMarking(kReduceMemoryFootprintMask, kNoGCCallbackFlags, |
| "idle"); |
| } |
| |
| |
| 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()) { |
| // Check that the string is actually internalized. |
| CHECK((*p)->IsTheHole() || (*p)->IsUndefined() || |
| (*p)->IsInternalizedString()); |
| } |
| } |
| } |
| }; |
| |
| |
| static void VerifyStringTable(Heap* heap) { |
| StringTableVerifier verifier; |
| heap->string_table()->IterateElements(&verifier); |
| } |
| #endif // VERIFY_HEAP |
| |
| |
| bool Heap::ReserveSpace(Reservation* reservations) { |
| 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 == LO_SPACE) { |
| 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(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, "failed to reserve space in the new space"); |
| } else { |
| if (counter > 1) { |
| CollectAllGarbage( |
| kReduceMemoryFootprintMask | kAbortIncrementalMarkingMask, |
| "failed to reserve space in paged or large " |
| "object space, trying to reduce memory footprint"); |
| } else { |
| CollectAllGarbage( |
| kAbortIncrementalMarkingMask, |
| "failed to reserve space in paged or large object space"); |
| } |
| } |
| 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()) { |
| // 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()) { |
| 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); |
| if (survival_rate > kYoungSurvivalRateHighThreshold) { |
| high_survival_rate_period_length_++; |
| } else { |
| high_survival_rate_period_length_ = 0; |
| } |
| } |
| |
| bool Heap::PerformGarbageCollection( |
| GarbageCollector collector, const v8::GCCallbackFlags gc_callback_flags) { |
| int freed_global_handles = 0; |
| |
| if (collector != SCAVENGER) { |
| 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(), collector == MARK_COMPACTOR |
| ? GCTracer::Scope::MC_EXTERNAL_PROLOGUE |
| : GCTracer::Scope::SCAVENGER_EXTERNAL_PROLOGUE); |
| VMState<EXTERNAL> state(isolate_); |
| HandleScope handle_scope(isolate_); |
| CallGCPrologueCallbacks(gc_type, kNoGCCallbackFlags); |
| } |
| } |
| |
| EnsureFromSpaceIsCommitted(); |
| |
| int start_new_space_size = Heap::new_space()->SizeAsInt(); |
| |
| if (IsHighSurvivalRate()) { |
| // We speed up the incremental marker if it is running so that it |
| // does not fall behind the rate of promotion, which would cause a |
| // constantly growing old space. |
| incremental_marking()->NotifyOfHighPromotionRate(); |
| } |
| |
| { |
| Heap::PretenuringScope pretenuring_scope(this); |
| |
| if (collector == MARK_COMPACTOR) { |
| UpdateOldGenerationAllocationCounter(); |
| // Perform mark-sweep with optional compaction. |
| MarkCompact(); |
| old_gen_exhausted_ = false; |
| 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_ += |
| static_cast<size_t>(promoted_objects_size_); |
| old_generation_size_at_last_gc_ = PromotedSpaceSizeOfObjects(); |
| } else { |
| Scavenge(); |
| } |
| |
| 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(); |
| intptr_t old_gen_size = PromotedSpaceSizeOfObjects(); |
| if (collector == MARK_COMPACTOR) { |
| // Register the amount of external allocated memory. |
| amount_of_external_allocated_memory_at_last_global_gc_ = |
| amount_of_external_allocated_memory_; |
| 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(), collector == MARK_COMPACTOR |
| ? GCTracer::Scope::MC_EXTERNAL_EPILOGUE |
| : GCTracer::Scope::SCAVENGER_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) { |
| 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) { |
| 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); |
| |
| gc_state_ = 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::MarkCompactEpilogue() { |
| gc_state_ = NOT_IN_GC; |
| |
| isolate_->counters()->objs_since_last_full()->Set(0); |
| |
| incremental_marking()->Epilogue(); |
| |
| PreprocessStackTraces(); |
| DCHECK(incremental_marking()->IsStopped()); |
| |
| // We finished a marking cycle. We can uncommit the marking deque until |
| // we start marking again. |
| mark_compact_collector()->marking_deque()->Uninitialize(); |
| mark_compact_collector()->EnsureMarkingDequeIsCommitted( |
| MarkCompactCollector::kMinMarkingDequeSize); |
| } |
| |
| |
| void Heap::MarkCompactPrologue() { |
| // At any old GC clear the keyed lookup cache to enable collection of unused |
| // maps. |
| isolate_->keyed_lookup_cache()->Clear(); |
| 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(); |
| } |
| |
| |
| #ifdef VERIFY_HEAP |
| // Visitor class to verify pointers in code or data space do not point into |
| // new space. |
| class VerifyNonPointerSpacePointersVisitor : public ObjectVisitor { |
| public: |
| explicit VerifyNonPointerSpacePointersVisitor(Heap* heap) : heap_(heap) {} |
| |
| void VisitPointers(Object** start, Object** end) override { |
| for (Object** current = start; current < end; current++) { |
| if ((*current)->IsHeapObject()) { |
| CHECK(!heap_->InNewSpace(HeapObject::cast(*current))); |
| } |
| } |
| } |
| |
| private: |
| Heap* heap_; |
| }; |
| |
| |
| static void VerifyNonPointerSpacePointers(Heap* heap) { |
| // Verify that there are no pointers to new space in spaces where we |
| // do not expect them. |
| VerifyNonPointerSpacePointersVisitor v(heap); |
| HeapObjectIterator code_it(heap->code_space()); |
| for (HeapObject* object = code_it.Next(); object != NULL; |
| object = code_it.Next()) |
| object->Iterate(&v); |
| } |
| #endif // VERIFY_HEAP |
| |
| |
| 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(); |
| } |
| |
| |
| static bool 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(); |
| } |
| |
| |
| 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::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); |
| |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) VerifyNonPointerSpacePointers(this); |
| #endif |
| |
| gc_state_ = SCAVENGE; |
| |
| // Implements Cheney's copying algorithm |
| LOG(isolate_, ResourceEvent("scavenge", "begin")); |
| |
| // Used for updating survived_since_last_expansion_ at function end. |
| intptr_t survived_watermark = PromotedSpaceSizeOfObjects(); |
| |
| scavenge_collector_->SelectScavengingVisitorsTable(); |
| |
| array_buffer_tracker()->PrepareDiscoveryInNewSpace(); |
| |
| // 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); |
| |
| if (FLAG_scavenge_reclaim_unmodified_objects) { |
| 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>::IterateWithWrapper(this, |
| Scavenger::ScavengeObject); |
| } |
| |
| { |
| 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 encountered weak cells. |
| scavenge_visitor.VisitPointer(&encountered_weak_cells_); |
| } |
| |
| { |
| // 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); |
| } |
| |
| if (FLAG_scavenge_reclaim_unmodified_objects) { |
| isolate()->global_handles()->MarkNewSpaceWeakUnmodifiedObjectsPending( |
| &IsUnscavengedHeapObject); |
| |
| isolate()->global_handles()->IterateNewSpaceWeakUnmodifiedRoots( |
| &scavenge_visitor); |
| new_space_front = DoScavenge(&scavenge_visitor, new_space_front); |
| } else { |
| TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_OBJECT_GROUPS); |
| while (isolate()->global_handles()->IterateObjectGroups( |
| &scavenge_visitor, &IsUnscavengedHeapObject)) { |
| new_space_front = DoScavenge(&scavenge_visitor, new_space_front); |
| } |
| isolate()->global_handles()->RemoveObjectGroups(); |
| isolate()->global_handles()->RemoveImplicitRefGroups(); |
| |
| isolate()->global_handles()->IdentifyNewSpaceWeakIndependentHandles( |
| &IsUnscavengedHeapObject); |
| |
| isolate()->global_handles()->IterateNewSpaceWeakIndependentRoots( |
| &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()); |
| |
| array_buffer_tracker()->FreeDead(true); |
| |
| // Update how much has survived scavenge. |
| IncrementYoungSurvivorsCounter(static_cast<int>( |
| (PromotedSpaceSizeOfObjects() - survived_watermark) + new_space_.Size())); |
| |
| LOG(isolate_, ResourceEvent("scavenge", "end")); |
| |
| gc_state_ = 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. |
| heap->FinalizeExternalString(String::cast(*p)); |
| return NULL; |
| } |
| |
| // String is still reachable. |
| return String::cast(first_word.ToForwardingAddress()); |
| } |
| |
| |
| 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_.Iterate(&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()); |
| |
| IteratePromotedObject(target, static_cast<int>(size), was_marked_black, |
| &Scavenger::ScavengeObject); |
| } |
| } |
| |
| // 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) { |
| return array_buffer_tracker()->RegisterNew(buffer); |
| } |
| |
| |
| void Heap::UnregisterArrayBuffer(JSArrayBuffer* buffer) { |
| return array_buffer_tracker()->Unregister(buffer); |
| } |
| |
| |
| void Heap::ConfigureInitialOldGenerationSize() { |
| if (!old_generation_size_configured_ && tracer()->SurvivalEventsRecorded()) { |
| old_generation_allocation_limit_ = |
| Max(kMinimumOldGenerationAllocationLimit, |
| static_cast<intptr_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::FromInt(0)); |
| 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::FromInt(0)); |
| map->set_raw_transitions(Smi::FromInt(0)); |
| 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::FromInt(0)); |
| 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_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) |
| #define ALLOCATE_SIMD128_MAP(TYPE, Type, type, lane_count, lane_type) \ |
| ALLOCATE_PRIMITIVE_MAP(SIMD128_VALUE_TYPE, Type::kSize, type, \ |
| Context::TYPE##_FUNCTION_INDEX) |
| SIMD128_TYPES(ALLOCATE_SIMD128_MAP) |
| #undef ALLOCATE_SIMD128_MAP |
| 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); |
| |
| 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(EXTERNAL_ONE_BYTE_STRING_TYPE, |
| ExternalOneByteString::kSize); |
| 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(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, 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, 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 = 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(double value, 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 <= Page::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); |
| HeapNumber::cast(result)->set_value(value); |
| return result; |
| } |
| |
| #define SIMD_ALLOCATE_DEFINITION(TYPE, Type, type, lane_count, lane_type) \ |
| AllocationResult Heap::Allocate##Type(lane_type lanes[lane_count], \ |
| PretenureFlag pretenure) { \ |
| int size = Type::kSize; \ |
| STATIC_ASSERT(Type::kSize <= Page::kMaxRegularHeapObjectSize); \ |
| \ |
| AllocationSpace space = SelectSpace(pretenure); \ |
| \ |
| HeapObject* result = nullptr; \ |
| { \ |
| AllocationResult allocation = \ |
| AllocateRaw(size, space, kSimd128Unaligned); \ |
| if (!allocation.To(&result)) return allocation; \ |
| } \ |
| \ |
| result->set_map_no_write_barrier(type##_map()); \ |
| Type* instance = Type::cast(result); \ |
| for (int i = 0; i < lane_count; i++) { \ |
| instance->set_lane(i, lanes[i]); \ |
| } \ |
| return result; \ |
| } |
| SIMD128_TYPES(SIMD_ALLOCATE_DEFINITION) |
| #undef SIMD_ALLOCATE_DEFINITION |
| |
| |
| AllocationResult Heap::AllocateCell(Object* value) { |
| int size = Cell::kSize; |
| STATIC_ASSERT(Cell::kSize <= Page::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 <= Page::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::FromInt(0))); |
| cell->set_value(the_hole_value()); |
| return result; |
| } |
| |
| |
| AllocationResult Heap::AllocateWeakCell(HeapObject* value) { |
| int size = WeakCell::kSize; |
| STATIC_ASSERT(WeakCell::kSize <= Page::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; |
| } |
| |
| |
| void Heap::CreateApiObjects() { |
| HandleScope scope(isolate()); |
| Factory* factory = isolate()->factory(); |
| Handle<Map> new_neander_map = |
| factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize); |
| |
| // Don't use Smi-only elements optimizations for objects with the neander |
| // map. There are too many cases where element values are set directly with a |
| // bottleneck to trap the Smi-only -> fast elements transition, and there |
| // appears to be no benefit for optimize this case. |
| new_neander_map->set_elements_kind(TERMINAL_FAST_ELEMENTS_KIND); |
| set_neander_map(*new_neander_map); |
| |
| Handle<JSObject> listeners = factory->NewNeanderObject(); |
| Handle<FixedArray> elements = factory->NewFixedArray(2); |
| elements->set(0, Smi::FromInt(0)); |
| listeners->set_elements(*elements); |
| set_message_listeners(*listeners); |
| } |
| |
| |
| 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_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(), false, "undefined", |
| Oddball::kUndefined); |
| |
| // Initialize the null_value. |
| Oddball::Initialize(isolate(), factory->null_value(), "null", |
| handle(Smi::FromInt(0), isolate()), false, "object", |
| Oddball::kNull); |
| |
| // Initialize the_hole_value. |
| Oddball::Initialize(isolate(), factory->the_hole_value(), "hole", |
| handle(Smi::FromInt(-1), isolate()), false, "undefined", |
| Oddball::kTheHole); |
| |
| // Initialize the true_value. |
| Oddball::Initialize(isolate(), factory->true_value(), "true", |
| handle(Smi::FromInt(1), isolate()), true, "boolean", |
| Oddball::kTrue); |
| |
| // Initialize the false_value. |
| Oddball::Initialize(isolate(), factory->false_value(), "false", |
| handle(Smi::FromInt(0), isolate()), false, "boolean", |
| Oddball::kFalse); |
| |
| set_uninitialized_value( |
| *factory->NewOddball(factory->uninitialized_map(), "uninitialized", |
| handle(Smi::FromInt(-1), isolate()), false, |
| "undefined", Oddball::kUninitialized)); |
| |
| set_arguments_marker( |
| *factory->NewOddball(factory->arguments_marker_map(), "arguments_marker", |
| handle(Smi::FromInt(-4), isolate()), false, |
| "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()), |
| false, "undefined", Oddball::kOther)); |
| |
| set_termination_exception(*factory->NewOddball( |
| factory->termination_exception_map(), "termination_exception", |
| handle(Smi::FromInt(-3), isolate()), false, "undefined", |
| Oddball::kOther)); |
| |
| set_exception(*factory->NewOddball(factory->exception_map(), "exception", |
| handle(Smi::FromInt(-5), isolate()), false, |
| "undefined", Oddball::kException)); |
| |
| set_optimized_out( |
| *factory->NewOddball(factory->optimized_out_map(), "optimized_out", |
| handle(Smi::FromInt(-6), isolate()), false, |
| "undefined", Oddball::kOptimizedOut)); |
| |
| set_stale_register( |
| *factory->NewOddball(factory->stale_register_map(), "stale_register", |
| handle(Smi::FromInt(-7), isolate()), false, |
| "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::FromInt(0)); |
| set_instanceof_cache_map(Smi::FromInt(0)); |
| set_instanceof_cache_answer(Smi::FromInt(0)); |
| |
| { |
| 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 |
| } |
| |
| // Allocate the dictionary of intrinsic function names. |
| Handle<NameDictionary> intrinsic_names = |
| NameDictionary::New(isolate(), Runtime::kNumFunctions, TENURED); |
| Runtime::InitializeIntrinsicFunctionNames(isolate(), intrinsic_names); |
| set_intrinsic_function_names(*intrinsic_names); |
| |
| Handle<NameDictionary> empty_properties_dictionary = |
| NameDictionary::New(isolate(), 0, TENURED); |
| empty_properties_dictionary->SetRequiresCopyOnCapacityChange(); |
| set_empty_properties_dictionary(*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())); |
| |
| // The symbol registry is initialized lazily. |
| set_symbol_registry(Smi::FromInt(0)); |
| |
| // 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()); |
| |
| { |
| StaticFeedbackVectorSpec spec; |
| FeedbackVectorSlot load_ic_slot = spec.AddLoadICSlot(); |
| FeedbackVectorSlot keyed_load_ic_slot = spec.AddKeyedLoadICSlot(); |
| FeedbackVectorSlot store_ic_slot = spec.AddStoreICSlot(); |
| FeedbackVectorSlot keyed_store_ic_slot = spec.AddKeyedStoreICSlot(); |
| |
| DCHECK_EQ(load_ic_slot, |
| FeedbackVectorSlot(TypeFeedbackVector::kDummyLoadICSlot)); |
| DCHECK_EQ(keyed_load_ic_slot, |
| FeedbackVectorSlot(TypeFeedbackVector::kDummyKeyedLoadICSlot)); |
| DCHECK_EQ(store_ic_slot, |
| FeedbackVectorSlot(TypeFeedbackVector::kDummyStoreICSlot)); |
| DCHECK_EQ(keyed_store_ic_slot, |
| FeedbackVectorSlot(TypeFeedbackVector::kDummyKeyedStoreICSlot)); |
| |
| Handle<TypeFeedbackMetadata> dummy_metadata = |
| TypeFeedbackMetadata::New(isolate(), &spec); |
| Handle<TypeFeedbackVector> dummy_vector = |
| TypeFeedbackVector::New(isolate(), dummy_metadata); |
| |
| Object* megamorphic = *TypeFeedbackVector::MegamorphicSentinel(isolate()); |
| dummy_vector->Set(load_ic_slot, megamorphic, SKIP_WRITE_BARRIER); |
| dummy_vector->Set(keyed_load_ic_slot, megamorphic, SKIP_WRITE_BARRIER); |
| dummy_vector->Set(store_ic_slot, megamorphic, SKIP_WRITE_BARRIER); |
| dummy_vector->Set(keyed_store_ic_slot, megamorphic, SKIP_WRITE_BARRIER); |
| |
| set_dummy_vector(*dummy_vector); |
| } |
| |
| { |
| Handle<WeakCell> cell = factory->NewWeakCell(factory->undefined_value()); |
| set_empty_weak_cell(*cell); |
| cell->clear(); |
| |
| Handle<FixedArray> cleared_optimized_code_map = |
| factory->NewFixedArray(SharedFunctionInfo::kEntriesStart, TENURED); |
| cleared_optimized_code_map->set(SharedFunctionInfo::kSharedCodeIndex, |
| *cell); |
| STATIC_ASSERT(SharedFunctionInfo::kEntriesStart == 1 && |
| SharedFunctionInfo::kSharedCodeIndex == 0); |
| set_cleared_optimized_code_map(*cleared_optimized_code_map); |
| } |
| |
| 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_script_list(Smi::FromInt(0)); |
| |
| 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)); |
| |
| // 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::kArrayProtectorValid)); |
| 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::kArrayProtectorValid)); |
| set_has_instance_protector(*cell); |
| |
| Handle<Cell> is_concat_spreadable_cell = factory->NewCell( |
| handle(Smi::FromInt(Isolate::kArrayProtectorValid), isolate())); |
| set_is_concat_spreadable_protector(*is_concat_spreadable_cell); |
| |
| Handle<Cell> species_cell = factory->NewCell( |
| handle(Smi::FromInt(Isolate::kArrayProtectorValid), isolate())); |
| set_species_protector(*species_cell); |
| |
| set_weak_stack_trace_list(Smi::FromInt(0)); |
| |
| set_noscript_shared_function_infos(Smi::FromInt(0)); |
| |
| // Initialize keyed lookup cache. |
| isolate_->keyed_lookup_cache()->Clear(); |
| |
| // Initialize context slot cache. |
| isolate_->context_slot_cache()->Clear(); |
| |
| // Initialize descriptor cache. |
| isolate_->descriptor_lookup_cache()->Clear(); |
| |
| // Initialize compilation cache. |
| isolate_->compilation_cache()->Clear(); |
| |
| CreateFixedStubs(); |
| } |
| |
| |
| bool Heap::RootCanBeWrittenAfterInitialization(Heap::RootListIndex root_index) { |
| switch (root_index) { |
| case kNumberStringCacheRootIndex: |
| case kInstanceofCacheFunctionRootIndex: |
| case kInstanceofCacheMapRootIndex: |
| case kInstanceofCacheAnswerRootIndex: |
| case kCodeStubsRootIndex: |
| case kEmptyScriptRootIndex: |
| case kSymbolRegistryRootIndex: |
| case kScriptListRootIndex: |
| case kMaterializedObjectsRootIndex: |
| case kMicrotaskQueueRootIndex: |
| case kDetachedContextsRootIndex: |
| case kWeakObjectToCodeTableRootIndex: |
| case kRetainedMapsRootIndex: |
| case kNoScriptSharedFunctionInfosRootIndex: |
| case kWeakStackTraceListRootIndex: |
| // 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)); |
| } |
| |
| |
| 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'. |
| int number_string_cache_size = max_semi_space_size_ / 512; |
| number_string_cache_size = Max(kInitialNumberStringCacheSize * 2, |
| Min(0x4000, number_string_cache_size)); |
| // There is a string and a number per entry so the length is twice the number |
| // of entries. |
| return 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 <= Page::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_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; |
| } |
| |
| void Heap::CreateFillerObjectAt(Address addr, int size, |
| ClearRecordedSlots mode) { |
| if (size == 0) return; |
| 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()); |
| } |
| |
| |
| 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; |
| |
| Page* page = Page::FromAddress(address); |
| // We can move the object start if: |
| // (1) the object is not in old space, |
| // (2) the page of the object was already swept, |
| // (3) the page was already concurrently swept. This case is an optimization |
| // for concurrent sweeping. The WasSwept predicate for concurrently swept |
| // pages is set after sweeping all pages. |
| return !InOldSpace(object) || page->SweepingDone(); |
| } |
| |
| |
| void Heap::AdjustLiveBytes(HeapObject* object, int by, InvocationMode mode) { |
| // 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() && |
| Marking::IsBlack(Marking::MarkBitFrom(object->address()))) { |
| if (mode == SEQUENTIAL_TO_SWEEPER) { |
| MemoryChunk::IncrementLiveBytesFromGC(object, by); |
| } else { |
| MemoryChunk::IncrementLiveBytesFromMutator(object, by); |
| } |
| } |
| } |
| |
| |
| FixedArrayBase* Heap::LeftTrimFixedArray(FixedArrayBase* object, |
| int elements_to_trim) { |
| 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 new_start = object->address() + 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. |
| CreateFillerObjectAt(object->address(), bytes_to_trim, |
| ClearRecordedSlots::kYes); |
| // 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. |
| DCHECK(CanMoveObjectStart(object)); |
| 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)); |
| |
| // 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)); |
| |
| // Maintain consistency of live bytes during incremental marking |
| Marking::TransferMark(this, object->address(), new_start); |
| AdjustLiveBytes(new_object, -bytes_to_trim, Heap::CONCURRENT_TO_SWEEPER); |
| |
| // Notify the heap profiler of change in object layout. |
| OnMoveEvent(new_object, object, new_object->Size()); |
| return new_object; |
| } |
| |
| |
| // Force instantiation of templatized method. |
| template void Heap::RightTrimFixedArray<Heap::SEQUENTIAL_TO_SWEEPER>( |
| FixedArrayBase*, int); |
| template void Heap::RightTrimFixedArray<Heap::CONCURRENT_TO_SWEEPER>( |
| FixedArrayBase*, int); |
| |
| |
| template<Heap::InvocationMode mode> |
| 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)) { |
| CreateFillerObjectAt(new_end, bytes_to_trim, ClearRecordedSlots::kYes); |
| } |
| |
| // 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, mode); |
| |
| // 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::FromInt(0), 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(); |
| // 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) or in large object space. |
| if (!code_space_->FirstPage()->Contains(address) && |
| MemoryChunk::FromAddress(address)->owner()->identity() != LO_SPACE) { |
| // 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() == NULL || |
| !memory_allocator()->code_range()->valid() || |
| memory_allocator()->code_range()->contains(code->address()) || |
| object_size <= code_space()->AreaSize()); |
| code->set_gc_metadata(Smi::FromInt(0)); |
| 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() == NULL || |
| !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); |
| 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()); |
| bytecode_array->CopyBytecodesTo(copy); |
| return copy; |
| } |
| |
| AllocationResult Heap::CopyCode(Code* code, Vector<byte> reloc_info) { |
| // Allocate ByteArray before the Code object, so that we do not risk |
| // leaving uninitialized Code object (and breaking the heap). |
| ByteArray* reloc_info_array = nullptr; |
| { |
| AllocationResult allocation = |
| AllocateByteArray(reloc_info.length(), TENURED); |
| if (!allocation.To(&reloc_info_array)) return allocation; |
| } |
| |
| int new_body_size = RoundUp(code->instruction_size(), kObjectAlignment); |
| |
| int new_obj_size = Code::SizeFor(new_body_size); |
| |
| Address old_addr = code->address(); |
| |
| size_t relocation_offset = |
| static_cast<size_t>(code->instruction_end() - old_addr); |
| |
| HeapObject* result = nullptr; |
| AllocationResult allocation = AllocateRaw(new_obj_size, CODE_SPACE); |
| if (!allocation.To(&result)) return allocation; |
| |
| // Copy code object. |
| Address new_addr = result->address(); |
| |
| // Copy header and instructions. |
| CopyBytes(new_addr, old_addr, relocation_offset); |
| |
| Code* new_code = Code::cast(result); |
| new_code->set_relocation_info(reloc_info_array); |
| |
| // Copy patched rinfo. |
| CopyBytes(new_code->relocation_start(), reloc_info.start(), |
| static_cast<size_t>(reloc_info.length())); |
| |
| // Relocate the copy. |
| DCHECK(IsAligned(bit_cast<intptr_t>(new_code->address()), kCodeAlignment)); |
| DCHECK(memory_allocator()->code_range() == NULL || |
| !memory_allocator()->code_range()->valid() || |
| memory_allocator()->code_range()->contains(code->address()) || |
| new_obj_size <= code_space()->AreaSize()); |
| |
| new_code->Relocate(new_addr - old_addr); |
| // We have to iterate over over the object and process its pointers when |
| // black allocation is on. |
| incremental_marking()->IterateBlackObject(new_code); |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) code->ObjectVerify(); |
| #endif |
| return new_code; |
| } |
| |
| |
| 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::FromInt(0)) 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()); |
| 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 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_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::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); |
| if (InNewSpace(obj)) { |
| CopyBlock(obj->address() + kPointerSize, src->address() + kPointerSize, |
| FixedArray::SizeFor(len) - kPointerSize); |
| return obj; |
| } |
| 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); |
| 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); |
| |
| return AllocateRaw(size, space); |
| } |
| |
| |
| 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 <= Page::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; |
| int attempts = 0; |
| do { |
| hash = isolate()->random_number_generator()->NextInt() & Name::kHashBitMask; |
| attempts++; |
| } while (hash == 0 && attempts < 30); |
| if (hash == 0) hash = 1; // never return 0 |
| |
| 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; |
| } |
| |
| |
| bool Heap::IsHeapIterable() { |
| // TODO(hpayer): This function is not correct. Allocation folding in old |
| // space breaks the iterability. |
| return new_space_top_after_last_gc_ == new_space()->top(); |
| } |
| |
| |
| void Heap::MakeHeapIterable() { |
| DCHECK(AllowHeapAllocation::IsAllowed()); |
| if (!IsHeapIterable()) { |
| CollectAllGarbage(kMakeHeapIterableMask, "Heap::MakeHeapIterable"); |
| } |
| if (mark_compact_collector()->sweeping_in_progress()) { |
| mark_compact_collector()->EnsureSweepingCompleted(); |
| } |
| DCHECK(IsHeapIterable()); |
| } |
| |
| |
| 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) { |
| PrintIsolate(isolate(), |
| "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) { |
| PrintIsolate(isolate(), |
| "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() { |
| intptr_t used = PromotedSpaceSizeOfObjects(); |
| intptr_t committed = CommittedOldGenerationMemory(); |
| return HasHighFragmentation(used, committed); |
| } |
| |
| |
| bool Heap::HasHighFragmentation(intptr_t used, intptr_t committed) { |
| const intptr_t kSlack = 16 * MB; |
| // Fragmentation is high if committed > 2 * used + kSlack. |
| // Rewrite the exression to avoid overflow. |
| return committed - used > used + kSlack; |
| } |
| |
| void Heap::SetOptimizeForMemoryUsage() { |
| // 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) { |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kPossibleGarbage; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| memory_reducer_->NotifyPossibleGarbage(event); |
| } |
| optimize_for_memory_usage_ = true; |
| } |
| |
| 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(const char* comment) { |
| if (incremental_marking()->IsMarking() && |
| (incremental_marking()->IsReadyToOverApproximateWeakClosure() || |
| (!incremental_marking()->finalize_marking_completed() && |
| mark_compact_collector()->marking_deque()->IsEmpty()))) { |
| FinalizeIncrementalMarking(comment); |
| } else if (incremental_marking()->IsComplete() || |
| (mark_compact_collector()->marking_deque()->IsEmpty())) { |
| CollectAllGarbage(current_gc_flags_, comment); |
| } |
| } |
| |
| |
| bool Heap::TryFinalizeIdleIncrementalMarking(double idle_time_in_ms) { |
| 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() && |
| gc_idle_time_handler_->ShouldDoOverApproximateWeakClosure( |
| idle_time_in_ms))) { |
| FinalizeIncrementalMarking( |
| "Idle notification: finalize incremental marking"); |
| return true; |
| } else if (incremental_marking()->IsComplete() || |
| (mark_compact_collector()->marking_deque()->IsEmpty() && |
| 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_, |
| "idle notification: finalize incremental marking"); |
| 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. |
| |
| // Code space, map space, and large object space do not use black pages. |
| // Hence we have to color all objects of the reservation first black to avoid |
| // unnecessary marking deque load. |
| if (incremental_marking()->black_allocation()) { |
| for (int i = CODE_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); |
| Marking::MarkBlack(Marking::MarkBitFrom(obj)); |
| MemoryChunk::IncrementLiveBytesFromGC(obj, obj->Size()); |
| addr += obj->Size(); |
| } |
| } |
| } |
| 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); |
| 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: { |
| if (incremental_marking()->incremental_marking_job()->IdleTaskPending()) { |
| result = true; |
| } else { |
| incremental_marking() |
| ->incremental_marking_job() |
| ->NotifyIdleTaskProgress(); |
| result = IncrementalMarkingJob::IdleTask::Step(this, deadline_in_ms) == |
| IncrementalMarkingJob::IdleTask::kDone; |
| } |
| break; |
| } |
| case DO_FULL_GC: { |
| DCHECK(contexts_disposed_ > 0); |
| HistogramTimerScope scope(isolate_->counters()->gc_context()); |
| TRACE_EVENT0("v8", "V8.GCContext"); |
| CollectAllGarbage(kNoGCFlags, "idle notification: contexts disposed"); |
| 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) { |
| PrintIsolate(isolate_, "%8.0f ms: ", isolate()->time_millis_since_init()); |
| PrintF( |
| "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 (memory_pressure_level_.Value() == MemoryPressureLevel::kCritical) { |
| CollectGarbageOnMemoryPressure("memory pressure"); |
| } else if (memory_pressure_level_.Value() == MemoryPressureLevel::kModerate) { |
| if (FLAG_incremental_marking && incremental_marking()->IsStopped()) { |
| StartIdleIncrementalMarking(); |
| } |
| } |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kPossibleGarbage; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| memory_reducer_->NotifyPossibleGarbage(event); |
| } |
| |
| void Heap::CollectGarbageOnMemoryPressure(const char* source) { |
| CollectAllGarbage(kReduceMemoryFootprintMask | kAbortIncrementalMarkingMask, |
| source); |
| } |
| |
| 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)); |
| } |
| } |
| } |
| |
| #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); |
| PagedSpace::ResetCodeStatistics(isolate()); |
| // We do not look for code in new space, map space, or old space. If code |
| // somehow ends up in those spaces, we would miss it here. |
| code_space_->CollectCodeStatistics(); |
| lo_space_->CollectCodeStatistics(); |
| PagedSpace::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 |
| |
| 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()); |
| |
| if (mark_compact_collector()->sweeping_in_progress()) { |
| // 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; |
| NewSpacePageIterator it(new_space_.FromSpaceStart(), |
| new_space_.FromSpaceEnd()); |
| while (it.has_next()) { |
| Page* page = it.next(); |
| for (Address cursor = page->area_start(), limit = page->area_end(); |
| cursor < limit; cursor += kPointerSize) { |
| Memory::Address_at(cursor) = kFromSpaceZapValue; |
| } |
| } |
| } |
| |
| void Heap::IteratePromotedObjectPointers(HeapObject* object, Address start, |
| Address end, bool record_slots, |
| ObjectSlotCallback callback) { |
| Address slot_address = start; |
| Page* page = Page::FromAddress(start); |
| |
| while (slot_address < end) { |
| Object** slot = reinterpret_cast<Object**>(slot_address); |
| Object* target = *slot; |
| if (target->IsHeapObject()) { |
| if (Heap::InFromSpace(target)) { |
| callback(reinterpret_cast<HeapObject**>(slot), |
| HeapObject::cast(target)); |
| Object* new_target = *slot; |
| if (InNewSpace(new_target)) { |
| SLOW_DCHECK(Heap::InToSpace(new_target)); |
| SLOW_DCHECK(new_target->IsHeapObject()); |
| RememberedSet<OLD_TO_NEW>::Insert(page, slot_address); |
| } |
| SLOW_DCHECK(!MarkCompactCollector::IsOnEvacuationCandidate(new_target)); |
| } else if (record_slots && |
| MarkCompactCollector::IsOnEvacuationCandidate(target)) { |
| mark_compact_collector()->RecordSlot(object, slot, target); |
| } |
| } |
| slot_address += kPointerSize; |
| } |
| } |
| |
| class IteratePromotedObjectsVisitor final : public ObjectVisitor { |
| public: |
| IteratePromotedObjectsVisitor(Heap* heap, HeapObject* target, |
| bool record_slots, ObjectSlotCallback callback) |
| : heap_(heap), |
| target_(target), |
| record_slots_(record_slots), |
| callback_(callback) {} |
| |
| V8_INLINE void VisitPointers(Object** start, Object** end) override { |
| heap_->IteratePromotedObjectPointers( |
| target_, reinterpret_cast<Address>(start), |
| reinterpret_cast<Address>(end), record_slots_, callback_); |
| } |
| |
| V8_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::MarkObject(heap_, code); |
| } |
| } |
| |
| private: |
| Heap* heap_; |
| HeapObject* target_; |
| bool record_slots_; |
| ObjectSlotCallback callback_; |
| }; |
| |
| void Heap::IteratePromotedObject(HeapObject* target, int size, |
| bool was_marked_black, |
| ObjectSlotCallback callback) { |
| // 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()) { |
| MarkBit mark_bit = Marking::MarkBitFrom(target); |
| record_slots = Marking::IsBlack(mark_bit); |
| } |
| |
| IteratePromotedObjectsVisitor visitor(this, target, record_slots, callback); |
| 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::MarkObject(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_.Iterate(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_->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: |
| case VISIT_ONLY_STRONG_FOR_SERIALIZATION: |
| 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(int max_semi_space_size, int max_old_space_size, |
| int 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_ = static_cast<intptr_t>(max_old_space_size) * MB; |
| } |
| if (max_executable_size > 0) { |
| max_executable_size_ = static_cast<intptr_t>(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_ = FLAG_max_semi_space_size * MB; |
| } |
| if (FLAG_max_old_space_size > 0) { |
| max_old_generation_size_ = |
| static_cast<intptr_t>(FLAG_max_old_space_size) * MB; |
| } |
| if (FLAG_max_executable_size > 0) { |
| max_executable_size_ = static_cast<intptr_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_ = Page::kPageSize; |
| } |
| |
| // The new space size must be a power of two to support single-bit testing |
| // for containment. |
| max_semi_space_size_ = |
| base::bits::RoundUpToPowerOfTwo32(max_semi_space_size_); |
| |
| if (FLAG_min_semi_space_size > 0) { |
| int initial_semispace_size = 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 %d 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; |
| max_old_generation_size_ = |
| Max(static_cast<intptr_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(Page::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_.SizeAsInt(); |
| *stats->new_space_capacity = static_cast<int>(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(); |
| memory_allocator()->Available(); |
| 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."); |
| } |
| } |
| } |
| |
| |
| intptr_t Heap::PromotedSpaceSizeOfObjects() { |
| return old_space_->SizeOfObjects() + code_space_->SizeOfObjects() + |
| map_space_->SizeOfObjects() + lo_space_->SizeOfObjects(); |
| } |
| |
| |
| int64_t Heap::PromotedExternalMemorySize() { |
| if (amount_of_external_allocated_memory_ <= |
| amount_of_external_allocated_memory_at_last_global_gc_) |
| return 0; |
| return amount_of_external_allocated_memory_ - |
| amount_of_external_allocated_memory_at_last_global_gc_; |
| } |
| |
| |
| 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::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; |
| } |
| |
| |
| intptr_t Heap::CalculateOldGenerationAllocationLimit(double factor, |
| intptr_t old_gen_size) { |
| CHECK(factor > 1.0); |
| CHECK(old_gen_size > 0); |
| intptr_t limit = static_cast<intptr_t>(old_gen_size * factor); |
| limit = Max(limit, old_gen_size + kMinimumOldGenerationAllocationLimit); |
| limit += new_space_.Capacity(); |
| intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2; |
| return Min(limit, halfway_to_the_max); |
| } |
| |
| |
| void Heap::SetOldGenerationAllocationLimit(intptr_t old_gen_size, |
| double gc_speed, |
| double mutator_speed) { |
| const double kConservativeHeapGrowingFactor = 1.3; |
| |
| double factor = HeapGrowingFactor(gc_speed, mutator_speed); |
| |
| if (FLAG_trace_gc_verbose) { |
| PrintIsolate(isolate_, |
| "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); |
| } |
| |
| // We set the old generation growing factor to 2 to grow the heap slower on |
| // memory-constrained devices. |
| if (max_old_generation_size_ <= kMaxOldSpaceSizeMediumMemoryDevice || |
| FLAG_optimize_for_size) { |
| factor = Min(factor, kMaxHeapGrowingFactorMemoryConstrained); |
| } |
| |
| if (memory_reducer_->ShouldGrowHeapSlowly() || optimize_for_memory_usage_) { |
| 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) { |
| PrintIsolate(isolate_, "Grow: old size: %" V8PRIdPTR |
| " KB, new limit: %" V8PRIdPTR " KB (%.1f)\n", |
| old_gen_size / KB, old_generation_allocation_limit_ / KB, |
| factor); |
| } |
| } |
| |
| |
| void Heap::DampenOldGenerationAllocationLimit(intptr_t old_gen_size, |
| double gc_speed, |
| double mutator_speed) { |
| double factor = HeapGrowingFactor(gc_speed, mutator_speed); |
| intptr_t limit = CalculateOldGenerationAllocationLimit(factor, old_gen_size); |
| if (limit < old_generation_allocation_limit_) { |
| if (FLAG_trace_gc_verbose) { |
| PrintIsolate(isolate_, |
| "Dampen: old size: %" V8PRIdPTR " KB, old limit: %" V8PRIdPTR |
| " KB, " |
| "new limit: %" V8PRIdPTR " KB (%.1f)\n", |
| old_gen_size / KB, old_generation_allocation_limit_ / KB, |
| limit / KB, factor); |
| } |
| old_generation_allocation_limit_ = limit; |
| } |
| } |
| |
| |
| 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 incremental marking. |
| incremental_marking_ = new IncrementalMarking(this); |
| |
| // Set up new space. |
| if (!new_space_.SetUp(initial_semispace_size_, max_semi_space_size_)) { |
| return false; |
| } |
| new_space_top_after_last_gc_ = new_space()->top(); |
| |
| // Initialize old space. |
| old_space_ = new OldSpace(this, OLD_SPACE, NOT_EXECUTABLE); |
| if (old_space_ == NULL) return false; |
| if (!old_space_->SetUp()) return false; |
| |
| // Initialize the code space, set its maximum capacity to the old |
| // generation size. It needs executable memory. |
| code_space_ = new OldSpace(this, CODE_SPACE, EXECUTABLE); |
| if (code_space_ == NULL) return false; |
| if (!code_space_->SetUp()) return false; |
| |
| // Initialize map space. |
| map_space_ = new MapSpace(this, MAP_SPACE); |
| if (map_space_ == NULL) return false; |
| 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. |
| lo_space_ = new LargeObjectSpace(this, LO_SPACE); |
| if (lo_space_ == NULL) return false; |
| 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); |
| |
| object_stats_ = new ObjectStats(this); |
| object_stats_->ClearObjectStats(true); |
| |
| scavenge_job_ = new ScavengeJob(); |
| |
| array_buffer_tracker_ = new ArrayBufferTracker(this); |
| |
| 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; |
| CreateApiObjects(); |
| |
| // 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::FromInt(0); |
| roots_[kRealStackLimitRootIndex] = Smi::FromInt(0); |
| } |
| |
| 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() { |
| deserialization_complete_ = true; |
| #ifdef DEBUG |
| // All pages right after bootstrapping must be marked as never-evacuate. |
| PagedSpaces spaces(this); |
| for (PagedSpace* s = spaces.next(); s != NULL; s = spaces.next()) { |
| PageIterator it(s); |
| while (it.has_next()) CHECK(it.next()->NeverEvacuate()); |
| } |
| #endif // DEBUG |
| } |
| |
| void Heap::SetEmbedderHeapTracer(EmbedderHeapTracer* tracer) { |
| mark_compact_collector()->SetEmbedderHeapTracer(tracer); |
| } |
| |
| bool Heap::UsingEmbedderHeapTracer() { |
| return mark_compact_collector()->UsingEmbedderHeapTracer(); |
| } |
| |
| void Heap::TracePossibleWrapper(JSObject* js_object) { |
| mark_compact_collector()->TracePossibleWrapper(js_object); |
| } |
| |
| void Heap::RegisterExternallyReferencedObject(Object** object) { |
| mark_compact_collector()->RegisterExternallyReferencedObject(object); |
| } |
| |
| void Heap::TearDown() { |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| |
| UpdateMaximumCommitted(); |
| |
| if (FLAG_print_cumulative_gc_stat) { |
| PrintF("\n"); |
| PrintF("gc_count=%d ", gc_count_); |
| PrintF("mark_sweep_count=%d ", ms_count_); |
| PrintF("max_gc_pause=%.1f ", get_max_gc_pause()); |
| PrintF("total_gc_time=%.1f ", total_gc_time_ms_); |
| PrintF("min_in_mutator=%.1f ", get_min_in_mutator()); |
| PrintF("max_alive_after_gc=%" V8PRIdPTR " ", get_max_alive_after_gc()); |
| PrintF("total_marking_time=%.1f ", tracer()->cumulative_marking_duration()); |
| PrintF("total_sweeping_time=%.1f ", |
| tracer()->cumulative_sweeping_duration()); |
| PrintF("\n\n"); |
| } |
| |
| if (FLAG_print_max_heap_committed) { |
| PrintF("\n"); |
| PrintF("maximum_committed_by_heap=%" V8PRIdPTR " ", |
| MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_new_space=%" V8PRIdPTR " ", |
| new_space_.MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_old_space=%" V8PRIdPTR " ", |
| old_space_->MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_code_space=%" V8PRIdPTR " ", |
| code_space_->MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_map_space=%" V8PRIdPTR " ", |
| map_space_->MaximumCommittedMemory()); |
| PrintF("maximum_committed_by_lo_space=%" V8PRIdPTR " ", |
| 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; |
| } |
| |
| delete object_stats_; |
| object_stats_ = nullptr; |
| |
| delete scavenge_job_; |
| scavenge_job_ = nullptr; |
| |
| delete array_buffer_tracker_; |
| array_buffer_tracker_ = nullptr; |
| |
| isolate_->global_handles()->TearDown(); |
| |
| external_string_table_.TearDown(); |
| |
| delete tracer_; |
| tracer_ = nullptr; |
| |
| new_space_.TearDown(); |
| |
| 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 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::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()); |
| } |
| |
| |
| 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)) { |
| store_buffer()->MoveEntriesToRememberedSet(); |
| Address slot_addr = reinterpret_cast<Address>(slot); |
| Page* page = Page::FromAddress(slot_addr); |
| DCHECK_EQ(page->owner()->identity(), OLD_SPACE); |
| RememberedSet<OLD_TO_NEW>::Remove(page, slot_addr); |
| RememberedSet<OLD_TO_OLD>::Remove(page, slot_addr); |
| } |
| } |
| |
| void Heap::ClearRecordedSlotRange(Address start, Address end) { |
| Page* page = Page::FromAddress(start); |
| if (!page->InNewSpace()) { |
| store_buffer()->MoveEntriesToRememberedSet(); |
| DCHECK_EQ(page->owner()->identity(), OLD_SPACE); |
| RememberedSet<OLD_TO_NEW>::RemoveRange(page, start, end); |
| RememberedSet<OLD_TO_OLD>::RemoveRange(page, start, end); |
| } |
| } |
| |
| 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), iterator_(NULL) {} |
| |
| |
| SpaceIterator::~SpaceIterator() { |
| // Delete active iterator if any. |
| delete iterator_; |
| } |
| |
| |
| bool SpaceIterator::has_next() { |
| // Iterate until no more spaces. |
| return current_space_ != LAST_SPACE; |
| } |
| |
| |
| ObjectIterator* SpaceIterator::next() { |
| if (iterator_ != NULL) { |
| delete iterator_; |
| iterator_ = NULL; |
| // Move to the next space |
| current_space_++; |
| if (current_space_ > LAST_SPACE) { |
| return NULL; |
| } |
| } |
| |
| // Return iterator for the new current space. |
| return CreateIterator(); |
| } |
| |
| |
| // Create an iterator for the space to iterate. |
| ObjectIterator* SpaceIterator::CreateIterator() { |
| DCHECK(iterator_ == NULL); |
| |
| switch (current_space_) { |
| case NEW_SPACE: |
| iterator_ = new SemiSpaceIterator(heap_->new_space()); |
| break; |
| case OLD_SPACE: |
| iterator_ = new HeapObjectIterator(heap_->old_space()); |
| break; |
| case CODE_SPACE: |
| iterator_ = new HeapObjectIterator(heap_->code_space()); |
| break; |
| case MAP_SPACE: |
| iterator_ = new HeapObjectIterator(heap_->map_space()); |
| break; |
| case LO_SPACE: |
| iterator_ = new LargeObjectIterator(heap_->lo_space()); |
| break; |
| } |
| |
| // Return the newly allocated iterator; |
| DCHECK(iterator_ != NULL); |
| return iterator_; |
| } |
| |
| |
| 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; |
| MarkBit mark_bit = Marking::MarkBitFrom(object); |
| return Marking::IsWhite(mark_bit); |
| } |
| |
| 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); |
| MarkBit mark_bit = Marking::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) |
| : make_heap_iterable_helper_(heap), |
| no_heap_allocation_(), |
| heap_(heap), |
| filtering_(filtering), |
| filter_(nullptr), |
| space_iterator_(nullptr), |
| object_iterator_(nullptr) { |
| 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(); |
| } |
| |
| |
| 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 |
| // Make sure the last iterator is deallocated. |
| delete object_iterator_; |
| 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_ == nullptr) return nullptr; |
| |
| if (HeapObject* obj = object_iterator_->next_object()) { |
| // 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(); |
| if (HeapObject* obj = object_iterator_->next_object()) { |
| return obj; |
| } |
| } |
| } |
| // Done with the last space. |
| object_iterator_ = 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::UpdateCumulativeGCStatistics(double duration, |
| double spent_in_mutator, |
| double marking_time) { |
| if (FLAG_print_cumulative_gc_stat) { |
| total_gc_time_ms_ += duration; |
| max_gc_pause_ = Max(max_gc_pause_, duration); |
| max_alive_after_gc_ = Max(max_alive_after_gc_, SizeOfObjects()); |
| min_in_mutator_ = Min(min_in_mutator_, spent_in_mutator); |
| } else if (FLAG_trace_gc_verbose) { |
| total_gc_time_ms_ += duration; |
| } |
| |
| marking_time_ += marking_time; |
| } |
| |
| |
| int KeyedLookupCache::Hash(Handle<Map> map, Handle<Name> name) { |
| DisallowHeapAllocation no_gc; |
| // Uses only lower 32 bits if pointers are larger. |
| uintptr_t addr_hash = |
| static_cast<uint32_t>(reinterpret_cast<uintptr_t>(*map)) >> kMapHashShift; |
| return static_cast<uint32_t>((addr_hash ^ name->Hash()) & kCapacityMask); |
| } |
| |
| |
| int KeyedLookupCache::Lookup(Handle<Map> map, Handle<Name> name) { |
| DisallowHeapAllocation no_gc; |
| int index = (Hash(map, name) & kHashMask); |
| for (int i = 0; i < kEntriesPerBucket; i++) { |
| Key& key = keys_[index + i]; |
| if ((key.map == *map) && key.name->Equals(*name)) { |
| return field_offsets_[index + i]; |
| } |
| } |
| return kNotFound; |
| } |
| |
| |
| void KeyedLookupCache::Update(Handle<Map> map, Handle<Name> name, |
| int field_offset) { |
| DisallowHeapAllocation no_gc; |
| if (!name->IsUniqueName()) { |
| if (!StringTable::InternalizeStringIfExists( |
| name->GetIsolate(), Handle<String>::cast(name)).ToHandle(&name)) { |
| return; |
| } |
| } |
| // This cache is cleared only between mark compact passes, so we expect the |
| // cache to only contain old space names. |
| DCHECK(!map->GetIsolate()->heap()->InNewSpace(*name)); |
| |
| int index = (Hash(map, name) & kHashMask); |
| // After a GC there will be free slots, so we use them in order (this may |
| // help to get the most frequently used one in position 0). |
| for (int i = 0; i < kEntriesPerBucket; i++) { |
| Key& key = keys_[index]; |
| Object* free_entry_indicator = NULL; |
| if (key.map == free_entry_indicator) { |
| key.map = *map; |
| key.name = *name; |
| field_offsets_[index + i] = field_offset; |
| return; |
| } |
| } |
| // No free entry found in this bucket, so we move them all down one and |
| // put the new entry at position zero. |
| for (int i = kEntriesPerBucket - 1; i > 0; i--) { |
| Key& key = keys_[index + i]; |
| Key& key2 = keys_[index + i - 1]; |
| key = key2; |
| field_offsets_[index + i] = field_offsets_[index + i - 1]; |
| } |
| |
| // Write the new first entry. |
| Key& key = keys_[index]; |
| key.map = *map; |
| key.name = *name; |
| field_offsets_[index] = field_offset; |
| } |
| |
| |
| void KeyedLookupCache::Clear() { |
| for (int index = 0; index < kLength; index++) keys_[index].map = NULL; |
| } |
| |
| |
| void DescriptorLookupCache::Clear() { |
| for (int index = 0; index < kLength; index++) keys_[index].source = NULL; |
| } |
| |
| void Heap::ExternalStringTable::CleanUp() { |
| int last = 0; |
| for (int i = 0; i < new_space_strings_.length(); ++i) { |
| if (new_space_strings_[i] == heap_->the_hole_value()) { |
| continue; |
| } |
| DCHECK(new_space_strings_[i]->IsExternalString()); |
| if (heap_->InNewSpace(new_space_strings_[i])) { |
| new_space_strings_[last++] = new_space_strings_[i]; |
| } else { |
| old_space_strings_.Add(new_space_strings_[i]); |
| } |
| } |
| new_space_strings_.Rewind(last); |
| new_space_strings_.Trim(); |
| |
| last = 0; |
| for (int i = 0; i < old_space_strings_.length(); ++i) { |
| if (old_space_strings_[i] == heap_->the_hole_value()) { |
| continue; |
| } |
| DCHECK(old_space_strings_[i]->IsExternalString()); |
| DCHECK(!heap_->InNewSpace(old_space_strings_[i])); |
| old_space_strings_[last++] = old_space_strings_[i]; |
| } |
| 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) { |
| heap_->FinalizeExternalString(ExternalString::cast(new_space_strings_[i])); |
| } |
| new_space_strings_.Free(); |
| for (int i = 0; i < old_space_strings_.length(); ++i) { |
| heap_->FinalizeExternalString(ExternalString::cast(old_space_strings_[i])); |
| } |
| 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 (index >= ObjectStats::OBJECT_STATS_COUNT) return 0; |
| return object_stats_->object_count_last_gc(index); |
| } |
| |
| |
| size_t Heap::ObjectSizeAtLastGC(size_t index) { |
| if (index >= ObjectStats::OBJECT_STATS_COUNT) return 0; |
| return 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 |