| // Copyright 2010 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "v8.h" |
| |
| #include "accessors.h" |
| #include "api.h" |
| #include "bootstrapper.h" |
| #include "codegen-inl.h" |
| #include "compilation-cache.h" |
| #include "debug.h" |
| #include "heap-profiler.h" |
| #include "global-handles.h" |
| #include "liveobjectlist-inl.h" |
| #include "mark-compact.h" |
| #include "natives.h" |
| #include "objects-visiting.h" |
| #include "runtime-profiler.h" |
| #include "scanner-base.h" |
| #include "scopeinfo.h" |
| #include "snapshot.h" |
| #include "v8threads.h" |
| #include "vm-state-inl.h" |
| #if V8_TARGET_ARCH_ARM && !V8_INTERPRETED_REGEXP |
| #include "regexp-macro-assembler.h" |
| #include "arm/regexp-macro-assembler-arm.h" |
| #endif |
| |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| String* Heap::hidden_symbol_; |
| Object* Heap::roots_[Heap::kRootListLength]; |
| Object* Heap::global_contexts_list_; |
| |
| |
| NewSpace Heap::new_space_; |
| OldSpace* Heap::old_pointer_space_ = NULL; |
| OldSpace* Heap::old_data_space_ = NULL; |
| OldSpace* Heap::code_space_ = NULL; |
| MapSpace* Heap::map_space_ = NULL; |
| CellSpace* Heap::cell_space_ = NULL; |
| LargeObjectSpace* Heap::lo_space_ = NULL; |
| |
| static const intptr_t kMinimumPromotionLimit = 2 * MB; |
| static const intptr_t kMinimumAllocationLimit = 8 * MB; |
| |
| intptr_t Heap::old_gen_promotion_limit_ = kMinimumPromotionLimit; |
| intptr_t Heap::old_gen_allocation_limit_ = kMinimumAllocationLimit; |
| |
| int Heap::old_gen_exhausted_ = false; |
| |
| int Heap::amount_of_external_allocated_memory_ = 0; |
| int Heap::amount_of_external_allocated_memory_at_last_global_gc_ = 0; |
| |
| // semispace_size_ should be a power of 2 and old_generation_size_ should be |
| // a multiple of Page::kPageSize. |
| #if defined(ANDROID) |
| static const int default_max_semispace_size_ = 2*MB; |
| intptr_t Heap::max_old_generation_size_ = 192*MB; |
| int Heap::initial_semispace_size_ = 128*KB; |
| intptr_t Heap::code_range_size_ = 0; |
| intptr_t Heap::max_executable_size_ = max_old_generation_size_; |
| #elif defined(V8_TARGET_ARCH_X64) |
| static const int default_max_semispace_size_ = 16*MB; |
| intptr_t Heap::max_old_generation_size_ = 1*GB; |
| int Heap::initial_semispace_size_ = 1*MB; |
| intptr_t Heap::code_range_size_ = 512*MB; |
| intptr_t Heap::max_executable_size_ = 256*MB; |
| #else |
| static const int default_max_semispace_size_ = 8*MB; |
| intptr_t Heap::max_old_generation_size_ = 512*MB; |
| int Heap::initial_semispace_size_ = 512*KB; |
| intptr_t Heap::code_range_size_ = 0; |
| intptr_t Heap::max_executable_size_ = 128*MB; |
| #endif |
| |
| // 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) |
| int Heap::max_semispace_size_ = V8_MAX_SEMISPACE_SIZE; |
| #else |
| int Heap::max_semispace_size_ = default_max_semispace_size_; |
| #endif |
| |
| // The snapshot semispace size will be the default semispace size if |
| // snapshotting is used and will be the requested semispace size as |
| // set up by ConfigureHeap otherwise. |
| int Heap::reserved_semispace_size_ = Heap::max_semispace_size_; |
| |
| List<Heap::GCPrologueCallbackPair> Heap::gc_prologue_callbacks_; |
| List<Heap::GCEpilogueCallbackPair> Heap::gc_epilogue_callbacks_; |
| |
| GCCallback Heap::global_gc_prologue_callback_ = NULL; |
| GCCallback Heap::global_gc_epilogue_callback_ = NULL; |
| HeapObjectCallback Heap::gc_safe_size_of_old_object_ = NULL; |
| |
| // 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. |
| int Heap::survived_since_last_expansion_ = 0; |
| intptr_t Heap::external_allocation_limit_ = 0; |
| |
| Heap::HeapState Heap::gc_state_ = NOT_IN_GC; |
| |
| int Heap::mc_count_ = 0; |
| int Heap::ms_count_ = 0; |
| unsigned int Heap::gc_count_ = 0; |
| |
| GCTracer* Heap::tracer_ = NULL; |
| |
| int Heap::unflattened_strings_length_ = 0; |
| |
| int Heap::always_allocate_scope_depth_ = 0; |
| int Heap::linear_allocation_scope_depth_ = 0; |
| int Heap::contexts_disposed_ = 0; |
| |
| int Heap::young_survivors_after_last_gc_ = 0; |
| int Heap::high_survival_rate_period_length_ = 0; |
| double Heap::survival_rate_ = 0; |
| Heap::SurvivalRateTrend Heap::previous_survival_rate_trend_ = Heap::STABLE; |
| Heap::SurvivalRateTrend Heap::survival_rate_trend_ = Heap::STABLE; |
| |
| #ifdef DEBUG |
| bool Heap::allocation_allowed_ = true; |
| |
| int Heap::allocation_timeout_ = 0; |
| bool Heap::disallow_allocation_failure_ = false; |
| #endif // DEBUG |
| |
| intptr_t GCTracer::alive_after_last_gc_ = 0; |
| double GCTracer::last_gc_end_timestamp_ = 0.0; |
| int GCTracer::max_gc_pause_ = 0; |
| intptr_t GCTracer::max_alive_after_gc_ = 0; |
| int GCTracer::min_in_mutator_ = kMaxInt; |
| |
| intptr_t Heap::Capacity() { |
| if (!HasBeenSetup()) return 0; |
| |
| return new_space_.Capacity() + |
| old_pointer_space_->Capacity() + |
| old_data_space_->Capacity() + |
| code_space_->Capacity() + |
| map_space_->Capacity() + |
| cell_space_->Capacity(); |
| } |
| |
| |
| intptr_t Heap::CommittedMemory() { |
| if (!HasBeenSetup()) return 0; |
| |
| return new_space_.CommittedMemory() + |
| old_pointer_space_->CommittedMemory() + |
| old_data_space_->CommittedMemory() + |
| code_space_->CommittedMemory() + |
| map_space_->CommittedMemory() + |
| cell_space_->CommittedMemory() + |
| lo_space_->Size(); |
| } |
| |
| intptr_t Heap::CommittedMemoryExecutable() { |
| if (!HasBeenSetup()) return 0; |
| |
| return MemoryAllocator::SizeExecutable(); |
| } |
| |
| |
| intptr_t Heap::Available() { |
| if (!HasBeenSetup()) return 0; |
| |
| return new_space_.Available() + |
| old_pointer_space_->Available() + |
| old_data_space_->Available() + |
| code_space_->Available() + |
| map_space_->Available() + |
| cell_space_->Available(); |
| } |
| |
| |
| bool Heap::HasBeenSetup() { |
| return old_pointer_space_ != NULL && |
| old_data_space_ != NULL && |
| code_space_ != NULL && |
| map_space_ != NULL && |
| cell_space_ != NULL && |
| lo_space_ != NULL; |
| } |
| |
| |
| int Heap::GcSafeSizeOfOldObject(HeapObject* object) { |
| ASSERT(!Heap::InNewSpace(object)); // Code only works for old objects. |
| ASSERT(!MarkCompactCollector::are_map_pointers_encoded()); |
| MapWord map_word = object->map_word(); |
| map_word.ClearMark(); |
| map_word.ClearOverflow(); |
| return object->SizeFromMap(map_word.ToMap()); |
| } |
| |
| |
| int Heap::GcSafeSizeOfOldObjectWithEncodedMap(HeapObject* object) { |
| ASSERT(!Heap::InNewSpace(object)); // Code only works for old objects. |
| ASSERT(MarkCompactCollector::are_map_pointers_encoded()); |
| uint32_t marker = Memory::uint32_at(object->address()); |
| if (marker == MarkCompactCollector::kSingleFreeEncoding) { |
| return kIntSize; |
| } else if (marker == MarkCompactCollector::kMultiFreeEncoding) { |
| return Memory::int_at(object->address() + kIntSize); |
| } else { |
| MapWord map_word = object->map_word(); |
| Address map_address = map_word.DecodeMapAddress(Heap::map_space()); |
| Map* map = reinterpret_cast<Map*>(HeapObject::FromAddress(map_address)); |
| return object->SizeFromMap(map); |
| } |
| } |
| |
| |
| GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space) { |
| // Is global GC requested? |
| if (space != NEW_SPACE || FLAG_gc_global) { |
| Counters::gc_compactor_caused_by_request.Increment(); |
| return MARK_COMPACTOR; |
| } |
| |
| // Is enough data promoted to justify a global GC? |
| if (OldGenerationPromotionLimitReached()) { |
| Counters::gc_compactor_caused_by_promoted_data.Increment(); |
| return MARK_COMPACTOR; |
| } |
| |
| // Have allocation in OLD and LO failed? |
| if (old_gen_exhausted_) { |
| Counters::gc_compactor_caused_by_oldspace_exhaustion.Increment(); |
| 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 (MemoryAllocator::MaxAvailable() <= new_space_.Size()) { |
| Counters::gc_compactor_caused_by_oldspace_exhaustion.Increment(); |
| return MARK_COMPACTOR; |
| } |
| |
| // Default |
| return SCAVENGER; |
| } |
| |
| |
| // TODO(1238405): Combine the infrastructure for --heap-stats and |
| // --log-gc to avoid the complicated preprocessor and flag testing. |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| void Heap::ReportStatisticsBeforeGC() { |
| // Heap::ReportHeapStatistics will also log NewSpace statistics when |
| // compiled with ENABLE_LOGGING_AND_PROFILING and --log-gc is set. The |
| // following logic is used to avoid double logging. |
| #if defined(DEBUG) && defined(ENABLE_LOGGING_AND_PROFILING) |
| 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(); |
| #elif defined(DEBUG) |
| if (FLAG_heap_stats) { |
| new_space_.CollectStatistics(); |
| ReportHeapStatistics("Before GC"); |
| new_space_.ClearHistograms(); |
| } |
| #elif defined(ENABLE_LOGGING_AND_PROFILING) |
| if (FLAG_log_gc) { |
| new_space_.CollectStatistics(); |
| new_space_.ReportStatistics(); |
| new_space_.ClearHistograms(); |
| } |
| #endif |
| } |
| |
| |
| #if defined(ENABLE_LOGGING_AND_PROFILING) |
| void Heap::PrintShortHeapStatistics() { |
| if (!FLAG_trace_gc_verbose) return; |
| PrintF("Memory allocator, used: %8" V8_PTR_PREFIX "d" |
| ", available: %8" V8_PTR_PREFIX "d\n", |
| MemoryAllocator::Size(), |
| MemoryAllocator::Available()); |
| PrintF("New space, used: %8" V8_PTR_PREFIX "d" |
| ", available: %8" V8_PTR_PREFIX "d\n", |
| Heap::new_space_.Size(), |
| new_space_.Available()); |
| PrintF("Old pointers, used: %8" V8_PTR_PREFIX "d" |
| ", available: %8" V8_PTR_PREFIX "d" |
| ", waste: %8" V8_PTR_PREFIX "d\n", |
| old_pointer_space_->Size(), |
| old_pointer_space_->Available(), |
| old_pointer_space_->Waste()); |
| PrintF("Old data space, used: %8" V8_PTR_PREFIX "d" |
| ", available: %8" V8_PTR_PREFIX "d" |
| ", waste: %8" V8_PTR_PREFIX "d\n", |
| old_data_space_->Size(), |
| old_data_space_->Available(), |
| old_data_space_->Waste()); |
| PrintF("Code space, used: %8" V8_PTR_PREFIX "d" |
| ", available: %8" V8_PTR_PREFIX "d" |
| ", waste: %8" V8_PTR_PREFIX "d\n", |
| code_space_->Size(), |
| code_space_->Available(), |
| code_space_->Waste()); |
| PrintF("Map space, used: %8" V8_PTR_PREFIX "d" |
| ", available: %8" V8_PTR_PREFIX "d" |
| ", waste: %8" V8_PTR_PREFIX "d\n", |
| map_space_->Size(), |
| map_space_->Available(), |
| map_space_->Waste()); |
| PrintF("Cell space, used: %8" V8_PTR_PREFIX "d" |
| ", available: %8" V8_PTR_PREFIX "d" |
| ", waste: %8" V8_PTR_PREFIX "d\n", |
| cell_space_->Size(), |
| cell_space_->Available(), |
| cell_space_->Waste()); |
| PrintF("Large object space, used: %8" V8_PTR_PREFIX "d" |
| ", available: %8" V8_PTR_PREFIX "d\n", |
| lo_space_->Size(), |
| lo_space_->Available()); |
| } |
| #endif |
| |
| |
| // 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) && defined(ENABLE_LOGGING_AND_PROFILING) |
| if (FLAG_heap_stats) { |
| new_space_.CollectStatistics(); |
| ReportHeapStatistics("After GC"); |
| } else if (FLAG_log_gc) { |
| new_space_.ReportStatistics(); |
| } |
| #elif defined(DEBUG) |
| if (FLAG_heap_stats) ReportHeapStatistics("After GC"); |
| #elif defined(ENABLE_LOGGING_AND_PROFILING) |
| if (FLAG_log_gc) new_space_.ReportStatistics(); |
| #endif |
| } |
| #endif // defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| |
| |
| void Heap::GarbageCollectionPrologue() { |
| TranscendentalCache::Clear(); |
| ClearJSFunctionResultCaches(); |
| gc_count_++; |
| unflattened_strings_length_ = 0; |
| #ifdef DEBUG |
| ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| allow_allocation(false); |
| |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| |
| if (FLAG_gc_verbose) Print(); |
| #endif |
| |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| ReportStatisticsBeforeGC(); |
| #endif |
| |
| LiveObjectList::GCPrologue(); |
| } |
| |
| intptr_t Heap::SizeOfObjects() { |
| intptr_t total = 0; |
| AllSpaces spaces; |
| for (Space* space = spaces.next(); space != NULL; space = spaces.next()) { |
| total += space->SizeOfObjects(); |
| } |
| return total; |
| } |
| |
| void Heap::GarbageCollectionEpilogue() { |
| LiveObjectList::GCEpilogue(); |
| #ifdef DEBUG |
| allow_allocation(true); |
| ZapFromSpace(); |
| |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| |
| if (FLAG_print_global_handles) GlobalHandles::Print(); |
| if (FLAG_print_handles) PrintHandles(); |
| if (FLAG_gc_verbose) Print(); |
| if (FLAG_code_stats) ReportCodeStatistics("After GC"); |
| #endif |
| |
| Counters::alive_after_last_gc.Set(static_cast<int>(SizeOfObjects())); |
| |
| Counters::symbol_table_capacity.Set(symbol_table()->Capacity()); |
| Counters::number_of_symbols.Set(symbol_table()->NumberOfElements()); |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| ReportStatisticsAfterGC(); |
| #endif |
| #ifdef ENABLE_DEBUGGER_SUPPORT |
| Debug::AfterGarbageCollection(); |
| #endif |
| } |
| |
| |
| void Heap::CollectAllGarbage(bool force_compaction) { |
| // 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. |
| MarkCompactCollector::SetForceCompaction(force_compaction); |
| CollectGarbage(OLD_POINTER_SPACE); |
| MarkCompactCollector::SetForceCompaction(false); |
| } |
| |
| |
| void Heap::CollectAllAvailableGarbage() { |
| // 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. |
| MarkCompactCollector::SetForceCompaction(true); |
| |
| // 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. |
| const int kMaxNumberOfAttempts = 7; |
| for (int attempt = 0; attempt < kMaxNumberOfAttempts; attempt++) { |
| if (!CollectGarbage(OLD_POINTER_SPACE, MARK_COMPACTOR)) { |
| break; |
| } |
| } |
| MarkCompactCollector::SetForceCompaction(false); |
| } |
| |
| |
| bool Heap::CollectGarbage(AllocationSpace space, GarbageCollector collector) { |
| // The VM is in the GC state until exiting this function. |
| VMState state(GC); |
| |
| #ifdef DEBUG |
| // Reset the allocation timeout to the GC interval, but make sure to |
| // allow at least a few allocations after a collection. The reason |
| // for this is that we have a lot of allocation sequences and we |
| // assume that a garbage collection will allow the subsequent |
| // allocation attempts to go through. |
| allocation_timeout_ = Max(6, FLAG_gc_interval); |
| #endif |
| |
| bool next_gc_likely_to_collect_more = false; |
| |
| { GCTracer tracer; |
| GarbageCollectionPrologue(); |
| // The GC count was incremented in the prologue. Tell the tracer about |
| // it. |
| tracer.set_gc_count(gc_count_); |
| |
| // Tell the tracer which collector we've selected. |
| tracer.set_collector(collector); |
| |
| HistogramTimer* rate = (collector == SCAVENGER) |
| ? &Counters::gc_scavenger |
| : &Counters::gc_compactor; |
| rate->Start(); |
| next_gc_likely_to_collect_more = |
| PerformGarbageCollection(collector, &tracer); |
| rate->Stop(); |
| |
| GarbageCollectionEpilogue(); |
| } |
| |
| |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| if (FLAG_log_gc) HeapProfiler::WriteSample(); |
| #endif |
| |
| return next_gc_likely_to_collect_more; |
| } |
| |
| |
| void Heap::PerformScavenge() { |
| GCTracer tracer; |
| PerformGarbageCollection(SCAVENGER, &tracer); |
| } |
| |
| |
| #ifdef DEBUG |
| // Helper class for verifying the symbol table. |
| class SymbolTableVerifier : public ObjectVisitor { |
| public: |
| SymbolTableVerifier() { } |
| void VisitPointers(Object** start, Object** end) { |
| // Visit all HeapObject pointers in [start, end). |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) { |
| // Check that the symbol is actually a symbol. |
| ASSERT((*p)->IsNull() || (*p)->IsUndefined() || (*p)->IsSymbol()); |
| } |
| } |
| } |
| }; |
| #endif // DEBUG |
| |
| |
| static void VerifySymbolTable() { |
| #ifdef DEBUG |
| SymbolTableVerifier verifier; |
| Heap::symbol_table()->IterateElements(&verifier); |
| #endif // DEBUG |
| } |
| |
| |
| void Heap::ReserveSpace( |
| int new_space_size, |
| int pointer_space_size, |
| int data_space_size, |
| int code_space_size, |
| int map_space_size, |
| int cell_space_size, |
| int large_object_size) { |
| NewSpace* new_space = Heap::new_space(); |
| PagedSpace* old_pointer_space = Heap::old_pointer_space(); |
| PagedSpace* old_data_space = Heap::old_data_space(); |
| PagedSpace* code_space = Heap::code_space(); |
| PagedSpace* map_space = Heap::map_space(); |
| PagedSpace* cell_space = Heap::cell_space(); |
| LargeObjectSpace* lo_space = Heap::lo_space(); |
| bool gc_performed = true; |
| while (gc_performed) { |
| gc_performed = false; |
| if (!new_space->ReserveSpace(new_space_size)) { |
| Heap::CollectGarbage(NEW_SPACE); |
| gc_performed = true; |
| } |
| if (!old_pointer_space->ReserveSpace(pointer_space_size)) { |
| Heap::CollectGarbage(OLD_POINTER_SPACE); |
| gc_performed = true; |
| } |
| if (!(old_data_space->ReserveSpace(data_space_size))) { |
| Heap::CollectGarbage(OLD_DATA_SPACE); |
| gc_performed = true; |
| } |
| if (!(code_space->ReserveSpace(code_space_size))) { |
| Heap::CollectGarbage(CODE_SPACE); |
| gc_performed = true; |
| } |
| if (!(map_space->ReserveSpace(map_space_size))) { |
| Heap::CollectGarbage(MAP_SPACE); |
| gc_performed = true; |
| } |
| if (!(cell_space->ReserveSpace(cell_space_size))) { |
| Heap::CollectGarbage(CELL_SPACE); |
| gc_performed = true; |
| } |
| // We add a slack-factor of 2 in order to have space for a series of |
| // large-object allocations that are only just larger than the page size. |
| large_object_size *= 2; |
| // The ReserveSpace method on the large object space checks how much |
| // we can expand the old generation. This includes expansion caused by |
| // allocation in the other spaces. |
| large_object_size += cell_space_size + map_space_size + code_space_size + |
| data_space_size + pointer_space_size; |
| if (!(lo_space->ReserveSpace(large_object_size))) { |
| Heap::CollectGarbage(LO_SPACE); |
| gc_performed = true; |
| } |
| } |
| } |
| |
| |
| void Heap::EnsureFromSpaceIsCommitted() { |
| if (new_space_.CommitFromSpaceIfNeeded()) return; |
| |
| // Committing memory to from space failed. |
| // Try shrinking and try again. |
| PagedSpaces spaces; |
| for (PagedSpace* space = spaces.next(); |
| space != NULL; |
| space = spaces.next()) { |
| space->RelinkPageListInChunkOrder(true); |
| } |
| |
| Shrink(); |
| if (new_space_.CommitFromSpaceIfNeeded()) return; |
| |
| // Committing memory to from space failed again. |
| // Memory is exhausted and we will die. |
| V8::FatalProcessOutOfMemory("Committing semi space failed."); |
| } |
| |
| |
| void Heap::ClearJSFunctionResultCaches() { |
| if (Bootstrapper::IsActive()) return; |
| |
| Object* context = global_contexts_list_; |
| while (!context->IsUndefined()) { |
| // Get the caches for this context: |
| FixedArray* caches = |
| Context::cast(context)->jsfunction_result_caches(); |
| // Clear the caches: |
| int length = caches->length(); |
| for (int i = 0; i < length; i++) { |
| JSFunctionResultCache::cast(caches->get(i))->Clear(); |
| } |
| // Get the next context: |
| context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK); |
| } |
| } |
| |
| |
| void Heap::ClearNormalizedMapCaches() { |
| if (Bootstrapper::IsActive()) return; |
| |
| Object* context = global_contexts_list_; |
| while (!context->IsUndefined()) { |
| Context::cast(context)->normalized_map_cache()->Clear(); |
| context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK); |
| } |
| } |
| |
| |
| #ifdef DEBUG |
| |
| enum PageWatermarkValidity { |
| ALL_VALID, |
| ALL_INVALID |
| }; |
| |
| static void VerifyPageWatermarkValidity(PagedSpace* space, |
| PageWatermarkValidity validity) { |
| PageIterator it(space, PageIterator::PAGES_IN_USE); |
| bool expected_value = (validity == ALL_VALID); |
| while (it.has_next()) { |
| Page* page = it.next(); |
| ASSERT(page->IsWatermarkValid() == expected_value); |
| } |
| } |
| #endif |
| |
| void Heap::UpdateSurvivalRateTrend(int start_new_space_size) { |
| double survival_rate = |
| (static_cast<double>(young_survivors_after_last_gc_) * 100) / |
| start_new_space_size; |
| |
| if (survival_rate > kYoungSurvivalRateThreshold) { |
| high_survival_rate_period_length_++; |
| } else { |
| high_survival_rate_period_length_ = 0; |
| } |
| |
| double survival_rate_diff = survival_rate_ - survival_rate; |
| |
| if (survival_rate_diff > kYoungSurvivalRateAllowedDeviation) { |
| set_survival_rate_trend(DECREASING); |
| } else if (survival_rate_diff < -kYoungSurvivalRateAllowedDeviation) { |
| set_survival_rate_trend(INCREASING); |
| } else { |
| set_survival_rate_trend(STABLE); |
| } |
| |
| survival_rate_ = survival_rate; |
| } |
| |
| bool Heap::PerformGarbageCollection(GarbageCollector collector, |
| GCTracer* tracer) { |
| bool next_gc_likely_to_collect_more = false; |
| |
| if (collector != SCAVENGER) { |
| PROFILE(CodeMovingGCEvent()); |
| } |
| |
| VerifySymbolTable(); |
| if (collector == MARK_COMPACTOR && global_gc_prologue_callback_) { |
| ASSERT(!allocation_allowed_); |
| GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL); |
| global_gc_prologue_callback_(); |
| } |
| |
| GCType gc_type = |
| collector == MARK_COMPACTOR ? kGCTypeMarkSweepCompact : kGCTypeScavenge; |
| |
| for (int i = 0; i < gc_prologue_callbacks_.length(); ++i) { |
| if (gc_type & gc_prologue_callbacks_[i].gc_type) { |
| gc_prologue_callbacks_[i].callback(gc_type, kNoGCCallbackFlags); |
| } |
| } |
| |
| EnsureFromSpaceIsCommitted(); |
| |
| int start_new_space_size = Heap::new_space()->SizeAsInt(); |
| |
| if (collector == MARK_COMPACTOR) { |
| // Perform mark-sweep with optional compaction. |
| MarkCompact(tracer); |
| |
| bool high_survival_rate_during_scavenges = IsHighSurvivalRate() && |
| IsStableOrIncreasingSurvivalTrend(); |
| |
| UpdateSurvivalRateTrend(start_new_space_size); |
| |
| intptr_t old_gen_size = PromotedSpaceSize(); |
| old_gen_promotion_limit_ = |
| old_gen_size + Max(kMinimumPromotionLimit, old_gen_size / 3); |
| old_gen_allocation_limit_ = |
| old_gen_size + Max(kMinimumAllocationLimit, old_gen_size / 2); |
| |
| if (high_survival_rate_during_scavenges && |
| IsStableOrIncreasingSurvivalTrend()) { |
| // Stable high survival rates of young objects both during partial and |
| // full collection indicate that mutator is either building or modifying |
| // a structure with a long lifetime. |
| // In this case we aggressively raise old generation memory limits to |
| // postpone subsequent mark-sweep collection and thus trade memory |
| // space for the mutation speed. |
| old_gen_promotion_limit_ *= 2; |
| old_gen_allocation_limit_ *= 2; |
| } |
| |
| old_gen_exhausted_ = false; |
| } else { |
| tracer_ = tracer; |
| Scavenge(); |
| tracer_ = NULL; |
| |
| UpdateSurvivalRateTrend(start_new_space_size); |
| } |
| |
| Counters::objs_since_last_young.Set(0); |
| |
| if (collector == MARK_COMPACTOR) { |
| DisableAssertNoAllocation allow_allocation; |
| GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL); |
| next_gc_likely_to_collect_more = |
| GlobalHandles::PostGarbageCollectionProcessing(); |
| } |
| |
| // Update relocatables. |
| Relocatable::PostGarbageCollectionProcessing(); |
| |
| 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_; |
| } |
| |
| GCCallbackFlags callback_flags = tracer->is_compacting() |
| ? kGCCallbackFlagCompacted |
| : kNoGCCallbackFlags; |
| for (int i = 0; i < gc_epilogue_callbacks_.length(); ++i) { |
| if (gc_type & gc_epilogue_callbacks_[i].gc_type) { |
| gc_epilogue_callbacks_[i].callback(gc_type, callback_flags); |
| } |
| } |
| |
| if (collector == MARK_COMPACTOR && global_gc_epilogue_callback_) { |
| ASSERT(!allocation_allowed_); |
| GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL); |
| global_gc_epilogue_callback_(); |
| } |
| VerifySymbolTable(); |
| |
| return next_gc_likely_to_collect_more; |
| } |
| |
| |
| void Heap::MarkCompact(GCTracer* tracer) { |
| gc_state_ = MARK_COMPACT; |
| LOG(ResourceEvent("markcompact", "begin")); |
| |
| MarkCompactCollector::Prepare(tracer); |
| |
| bool is_compacting = MarkCompactCollector::IsCompacting(); |
| |
| if (is_compacting) { |
| mc_count_++; |
| } else { |
| ms_count_++; |
| } |
| tracer->set_full_gc_count(mc_count_ + ms_count_); |
| |
| MarkCompactPrologue(is_compacting); |
| |
| MarkCompactCollector::CollectGarbage(); |
| |
| LOG(ResourceEvent("markcompact", "end")); |
| |
| gc_state_ = NOT_IN_GC; |
| |
| Shrink(); |
| |
| Counters::objs_since_last_full.Set(0); |
| |
| contexts_disposed_ = 0; |
| } |
| |
| |
| void Heap::MarkCompactPrologue(bool is_compacting) { |
| // At any old GC clear the keyed lookup cache to enable collection of unused |
| // maps. |
| KeyedLookupCache::Clear(); |
| ContextSlotCache::Clear(); |
| DescriptorLookupCache::Clear(); |
| |
| RuntimeProfiler::MarkCompactPrologue(is_compacting); |
| |
| CompilationCache::MarkCompactPrologue(); |
| |
| CompletelyClearInstanceofCache(); |
| |
| if (is_compacting) FlushNumberStringCache(); |
| |
| ClearNormalizedMapCaches(); |
| } |
| |
| |
| Object* Heap::FindCodeObject(Address a) { |
| Object* obj = NULL; // Initialization to please compiler. |
| { MaybeObject* maybe_obj = code_space_->FindObject(a); |
| if (!maybe_obj->ToObject(&obj)) { |
| obj = lo_space_->FindObject(a)->ToObjectUnchecked(); |
| } |
| } |
| return obj; |
| } |
| |
| |
| // Helper class for copying HeapObjects |
| class ScavengeVisitor: public ObjectVisitor { |
| public: |
| |
| void VisitPointer(Object** p) { ScavengePointer(p); } |
| |
| void VisitPointers(Object** start, Object** end) { |
| // Copy all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) ScavengePointer(p); |
| } |
| |
| private: |
| void ScavengePointer(Object** p) { |
| Object* object = *p; |
| if (!Heap::InNewSpace(object)) return; |
| Heap::ScavengeObject(reinterpret_cast<HeapObject**>(p), |
| reinterpret_cast<HeapObject*>(object)); |
| } |
| }; |
| |
| |
| // A queue of objects promoted during scavenge. Each object is accompanied |
| // by it's size to avoid dereferencing a map pointer for scanning. |
| class PromotionQueue { |
| public: |
| void Initialize(Address start_address) { |
| front_ = rear_ = reinterpret_cast<intptr_t*>(start_address); |
| } |
| |
| bool is_empty() { return front_ <= rear_; } |
| |
| void insert(HeapObject* target, int size) { |
| *(--rear_) = reinterpret_cast<intptr_t>(target); |
| *(--rear_) = size; |
| // Assert no overflow into live objects. |
| ASSERT(reinterpret_cast<Address>(rear_) >= Heap::new_space()->top()); |
| } |
| |
| void remove(HeapObject** target, int* size) { |
| *target = reinterpret_cast<HeapObject*>(*(--front_)); |
| *size = static_cast<int>(*(--front_)); |
| // Assert no underflow. |
| ASSERT(front_ >= rear_); |
| } |
| |
| private: |
| // The front of the queue is higher in memory than the rear. |
| intptr_t* front_; |
| intptr_t* rear_; |
| }; |
| |
| |
| // Shared state read by the scavenge collector and set by ScavengeObject. |
| static PromotionQueue promotion_queue; |
| |
| |
| #ifdef DEBUG |
| // Visitor class to verify pointers in code or data space do not point into |
| // new space. |
| class VerifyNonPointerSpacePointersVisitor: public ObjectVisitor { |
| public: |
| void VisitPointers(Object** start, Object**end) { |
| for (Object** current = start; current < end; current++) { |
| if ((*current)->IsHeapObject()) { |
| ASSERT(!Heap::InNewSpace(HeapObject::cast(*current))); |
| } |
| } |
| } |
| }; |
| |
| |
| static void VerifyNonPointerSpacePointers() { |
| // Verify that there are no pointers to new space in spaces where we |
| // do not expect them. |
| VerifyNonPointerSpacePointersVisitor v; |
| HeapObjectIterator code_it(Heap::code_space()); |
| for (HeapObject* object = code_it.next(); |
| object != NULL; object = code_it.next()) |
| object->Iterate(&v); |
| |
| HeapObjectIterator data_it(Heap::old_data_space()); |
| for (HeapObject* object = data_it.next(); |
| object != NULL; object = data_it.next()) |
| object->Iterate(&v); |
| } |
| #endif |
| |
| |
| void Heap::CheckNewSpaceExpansionCriteria() { |
| if (new_space_.Capacity() < new_space_.MaximumCapacity() && |
| survived_since_last_expansion_ > new_space_.Capacity()) { |
| // 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; |
| } |
| } |
| |
| |
| void Heap::Scavenge() { |
| #ifdef DEBUG |
| if (FLAG_enable_slow_asserts) VerifyNonPointerSpacePointers(); |
| #endif |
| |
| gc_state_ = SCAVENGE; |
| |
| Page::FlipMeaningOfInvalidatedWatermarkFlag(); |
| #ifdef DEBUG |
| VerifyPageWatermarkValidity(old_pointer_space_, ALL_VALID); |
| VerifyPageWatermarkValidity(map_space_, ALL_VALID); |
| #endif |
| |
| // We do not update an allocation watermark of the top page during linear |
| // allocation to avoid overhead. So to maintain the watermark invariant |
| // we have to manually cache the watermark and mark the top page as having an |
| // invalid watermark. This guarantees that dirty regions iteration will use a |
| // correct watermark even if a linear allocation happens. |
| old_pointer_space_->FlushTopPageWatermark(); |
| map_space_->FlushTopPageWatermark(); |
| |
| // Implements Cheney's copying algorithm |
| LOG(ResourceEvent("scavenge", "begin")); |
| |
| // Clear descriptor cache. |
| DescriptorLookupCache::Clear(); |
| |
| // Used for updating survived_since_last_expansion_ at function end. |
| intptr_t survived_watermark = PromotedSpaceSize(); |
| |
| CheckNewSpaceExpansionCriteria(); |
| |
| // 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_.ToSpaceLow(); |
| promotion_queue.Initialize(new_space_.ToSpaceHigh()); |
| |
| ScavengeVisitor scavenge_visitor; |
| // Copy roots. |
| IterateRoots(&scavenge_visitor, VISIT_ALL_IN_SCAVENGE); |
| |
| // Copy objects reachable from the old generation. By definition, |
| // there are no intergenerational pointers in code or data spaces. |
| IterateDirtyRegions(old_pointer_space_, |
| &IteratePointersInDirtyRegion, |
| &ScavengePointer, |
| WATERMARK_CAN_BE_INVALID); |
| |
| IterateDirtyRegions(map_space_, |
| &IteratePointersInDirtyMapsRegion, |
| &ScavengePointer, |
| WATERMARK_CAN_BE_INVALID); |
| |
| lo_space_->IterateDirtyRegions(&ScavengePointer); |
| |
| // Copy objects reachable from cells by scavenging cell values directly. |
| HeapObjectIterator cell_iterator(cell_space_); |
| for (HeapObject* cell = cell_iterator.next(); |
| cell != NULL; cell = cell_iterator.next()) { |
| if (cell->IsJSGlobalPropertyCell()) { |
| Address value_address = |
| reinterpret_cast<Address>(cell) + |
| (JSGlobalPropertyCell::kValueOffset - kHeapObjectTag); |
| scavenge_visitor.VisitPointer(reinterpret_cast<Object**>(value_address)); |
| } |
| } |
| |
| // Scavenge object reachable from the global contexts list directly. |
| scavenge_visitor.VisitPointer(BitCast<Object**>(&global_contexts_list_)); |
| |
| // Scavenge objects reachable from the runtime-profiler sampler |
| // window directly. |
| Object** sampler_window_address = RuntimeProfiler::SamplerWindowAddress(); |
| int sampler_window_size = RuntimeProfiler::SamplerWindowSize(); |
| scavenge_visitor.VisitPointers( |
| sampler_window_address, |
| sampler_window_address + sampler_window_size); |
| |
| new_space_front = DoScavenge(&scavenge_visitor, new_space_front); |
| |
| UpdateNewSpaceReferencesInExternalStringTable( |
| &UpdateNewSpaceReferenceInExternalStringTableEntry); |
| |
| LiveObjectList::UpdateReferencesForScavengeGC(); |
| |
| ASSERT(new_space_front == new_space_.top()); |
| |
| // Set age mark. |
| new_space_.set_age_mark(new_space_.top()); |
| |
| // Update how much has survived scavenge. |
| IncrementYoungSurvivorsCounter(static_cast<int>( |
| (PromotedSpaceSize() - survived_watermark) + new_space_.Size())); |
| |
| LOG(ResourceEvent("scavenge", "end")); |
| |
| gc_state_ = NOT_IN_GC; |
| } |
| |
| |
| String* Heap::UpdateNewSpaceReferenceInExternalStringTableEntry(Object** p) { |
| MapWord first_word = HeapObject::cast(*p)->map_word(); |
| |
| if (!first_word.IsForwardingAddress()) { |
| // Unreachable external string can be finalized. |
| FinalizeExternalString(String::cast(*p)); |
| return NULL; |
| } |
| |
| // String is still reachable. |
| return String::cast(first_word.ToForwardingAddress()); |
| } |
| |
| |
| void Heap::UpdateNewSpaceReferencesInExternalStringTable( |
| ExternalStringTableUpdaterCallback updater_func) { |
| ExternalStringTable::Verify(); |
| |
| if (ExternalStringTable::new_space_strings_.is_empty()) return; |
| |
| Object** start = &ExternalStringTable::new_space_strings_[0]; |
| Object** end = start + ExternalStringTable::new_space_strings_.length(); |
| Object** last = start; |
| |
| for (Object** p = start; p < end; ++p) { |
| ASSERT(Heap::InFromSpace(*p)); |
| String* target = updater_func(p); |
| |
| if (target == NULL) continue; |
| |
| ASSERT(target->IsExternalString()); |
| |
| if (Heap::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. |
| ExternalStringTable::AddOldString(target); |
| } |
| } |
| |
| ASSERT(last <= end); |
| ExternalStringTable::ShrinkNewStrings(static_cast<int>(last - start)); |
| } |
| |
| |
| static Object* ProcessFunctionWeakReferences(Object* function, |
| WeakObjectRetainer* retainer) { |
| Object* head = Heap::undefined_value(); |
| JSFunction* tail = NULL; |
| Object* candidate = function; |
| while (!candidate->IsUndefined()) { |
| // Check whether to keep the candidate in the list. |
| JSFunction* candidate_function = reinterpret_cast<JSFunction*>(candidate); |
| Object* retain = retainer->RetainAs(candidate); |
| if (retain != NULL) { |
| if (head->IsUndefined()) { |
| // First element in the list. |
| head = candidate_function; |
| } else { |
| // Subsequent elements in the list. |
| ASSERT(tail != NULL); |
| tail->set_next_function_link(candidate_function); |
| } |
| // Retained function is new tail. |
| tail = candidate_function; |
| } |
| // Move to next element in the list. |
| candidate = candidate_function->next_function_link(); |
| } |
| |
| // Terminate the list if there is one or more elements. |
| if (tail != NULL) { |
| tail->set_next_function_link(Heap::undefined_value()); |
| } |
| |
| return head; |
| } |
| |
| |
| void Heap::ProcessWeakReferences(WeakObjectRetainer* retainer) { |
| Object* head = undefined_value(); |
| Context* tail = NULL; |
| Object* candidate = global_contexts_list_; |
| while (!candidate->IsUndefined()) { |
| // Check whether to keep the candidate in the list. |
| Context* candidate_context = reinterpret_cast<Context*>(candidate); |
| Object* retain = retainer->RetainAs(candidate); |
| if (retain != NULL) { |
| if (head->IsUndefined()) { |
| // First element in the list. |
| head = candidate_context; |
| } else { |
| // Subsequent elements in the list. |
| ASSERT(tail != NULL); |
| tail->set_unchecked(Context::NEXT_CONTEXT_LINK, |
| candidate_context, |
| UPDATE_WRITE_BARRIER); |
| } |
| // Retained context is new tail. |
| tail = candidate_context; |
| |
| // Process the weak list of optimized functions for the context. |
| Object* function_list_head = |
| ProcessFunctionWeakReferences( |
| candidate_context->get(Context::OPTIMIZED_FUNCTIONS_LIST), |
| retainer); |
| candidate_context->set_unchecked(Context::OPTIMIZED_FUNCTIONS_LIST, |
| function_list_head, |
| UPDATE_WRITE_BARRIER); |
| } |
| // Move to next element in the list. |
| candidate = candidate_context->get(Context::NEXT_CONTEXT_LINK); |
| } |
| |
| // Terminate the list if there is one or more elements. |
| if (tail != NULL) { |
| tail->set_unchecked(Context::NEXT_CONTEXT_LINK, |
| Heap::undefined_value(), |
| UPDATE_WRITE_BARRIER); |
| } |
| |
| // Update the head of the list of contexts. |
| Heap::global_contexts_list_ = head; |
| } |
| |
| |
| class NewSpaceScavenger : public StaticNewSpaceVisitor<NewSpaceScavenger> { |
| public: |
| static inline void VisitPointer(Object** p) { |
| Object* object = *p; |
| if (!Heap::InNewSpace(object)) return; |
| Heap::ScavengeObject(reinterpret_cast<HeapObject**>(p), |
| reinterpret_cast<HeapObject*>(object)); |
| } |
| }; |
| |
| |
| Address Heap::DoScavenge(ObjectVisitor* scavenge_visitor, |
| Address new_space_front) { |
| do { |
| ASSERT(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()) { |
| HeapObject* object = HeapObject::FromAddress(new_space_front); |
| new_space_front += NewSpaceScavenger::IterateBody(object->map(), object); |
| } |
| |
| // Promote and process all the to-be-promoted objects. |
| while (!promotion_queue.is_empty()) { |
| HeapObject* target; |
| int size; |
| promotion_queue.remove(&target, &size); |
| |
| // Promoted object might be already partially visited |
| // during dirty regions iteration. Thus we search specificly |
| // for pointers to from semispace instead of looking for pointers |
| // to new space. |
| ASSERT(!target->IsMap()); |
| IterateAndMarkPointersToFromSpace(target->address(), |
| target->address() + size, |
| &ScavengePointer); |
| } |
| |
| // 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; |
| } |
| |
| |
| class ScavengingVisitor : public StaticVisitorBase { |
| public: |
| static void Initialize() { |
| table_.Register(kVisitSeqAsciiString, &EvacuateSeqAsciiString); |
| table_.Register(kVisitSeqTwoByteString, &EvacuateSeqTwoByteString); |
| table_.Register(kVisitShortcutCandidate, &EvacuateShortcutCandidate); |
| table_.Register(kVisitByteArray, &EvacuateByteArray); |
| table_.Register(kVisitFixedArray, &EvacuateFixedArray); |
| table_.Register(kVisitGlobalContext, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| VisitSpecialized<Context::kSize>); |
| |
| typedef ObjectEvacuationStrategy<POINTER_OBJECT> PointerObject; |
| |
| table_.Register(kVisitConsString, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| VisitSpecialized<ConsString::kSize>); |
| |
| table_.Register(kVisitSharedFunctionInfo, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| VisitSpecialized<SharedFunctionInfo::kSize>); |
| |
| table_.Register(kVisitJSFunction, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| VisitSpecialized<JSFunction::kSize>); |
| |
| table_.RegisterSpecializations<ObjectEvacuationStrategy<DATA_OBJECT>, |
| kVisitDataObject, |
| kVisitDataObjectGeneric>(); |
| |
| table_.RegisterSpecializations<ObjectEvacuationStrategy<POINTER_OBJECT>, |
| kVisitJSObject, |
| kVisitJSObjectGeneric>(); |
| |
| table_.RegisterSpecializations<ObjectEvacuationStrategy<POINTER_OBJECT>, |
| kVisitStruct, |
| kVisitStructGeneric>(); |
| } |
| |
| |
| static inline void Scavenge(Map* map, HeapObject** slot, HeapObject* obj) { |
| table_.GetVisitor(map)(map, slot, obj); |
| } |
| |
| |
| private: |
| enum ObjectContents { DATA_OBJECT, POINTER_OBJECT }; |
| enum SizeRestriction { SMALL, UNKNOWN_SIZE }; |
| |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| static void RecordCopiedObject(HeapObject* obj) { |
| bool should_record = false; |
| #ifdef DEBUG |
| should_record = FLAG_heap_stats; |
| #endif |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| should_record = should_record || FLAG_log_gc; |
| #endif |
| if (should_record) { |
| if (Heap::new_space()->Contains(obj)) { |
| Heap::new_space()->RecordAllocation(obj); |
| } else { |
| Heap::new_space()->RecordPromotion(obj); |
| } |
| } |
| } |
| #endif // defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| |
| // Helper function used by CopyObject to copy a source object to an |
| // allocated target object and update the forwarding pointer in the source |
| // object. Returns the target object. |
| INLINE(static HeapObject* MigrateObject(HeapObject* source, |
| HeapObject* target, |
| int size)) { |
| // Copy the content of source to target. |
| Heap::CopyBlock(target->address(), source->address(), size); |
| |
| // Set the forwarding address. |
| source->set_map_word(MapWord::FromForwardingAddress(target)); |
| |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| // Update NewSpace stats if necessary. |
| RecordCopiedObject(target); |
| #endif |
| HEAP_PROFILE(ObjectMoveEvent(source->address(), target->address())); |
| #if defined(ENABLE_LOGGING_AND_PROFILING) |
| if (Logger::is_logging() || CpuProfiler::is_profiling()) { |
| if (target->IsSharedFunctionInfo()) { |
| PROFILE(SFIMoveEvent(source->address(), target->address())); |
| } |
| } |
| #endif |
| return target; |
| } |
| |
| |
| template<ObjectContents object_contents, SizeRestriction size_restriction> |
| static inline void EvacuateObject(Map* map, |
| HeapObject** slot, |
| HeapObject* object, |
| int object_size) { |
| ASSERT((size_restriction != SMALL) || |
| (object_size <= Page::kMaxHeapObjectSize)); |
| ASSERT(object->Size() == object_size); |
| |
| if (Heap::ShouldBePromoted(object->address(), object_size)) { |
| MaybeObject* maybe_result; |
| |
| if ((size_restriction != SMALL) && |
| (object_size > Page::kMaxHeapObjectSize)) { |
| maybe_result = Heap::lo_space()->AllocateRawFixedArray(object_size); |
| } else { |
| if (object_contents == DATA_OBJECT) { |
| maybe_result = Heap::old_data_space()->AllocateRaw(object_size); |
| } else { |
| maybe_result = Heap::old_pointer_space()->AllocateRaw(object_size); |
| } |
| } |
| |
| Object* result = NULL; // Initialization to please compiler. |
| if (maybe_result->ToObject(&result)) { |
| HeapObject* target = HeapObject::cast(result); |
| *slot = MigrateObject(object, target, object_size); |
| |
| if (object_contents == POINTER_OBJECT) { |
| promotion_queue.insert(target, object_size); |
| } |
| |
| Heap::tracer()->increment_promoted_objects_size(object_size); |
| return; |
| } |
| } |
| Object* result = |
| Heap::new_space()->AllocateRaw(object_size)->ToObjectUnchecked(); |
| *slot = MigrateObject(object, HeapObject::cast(result), object_size); |
| return; |
| } |
| |
| |
| static inline void EvacuateFixedArray(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| int object_size = FixedArray::BodyDescriptor::SizeOf(map, object); |
| EvacuateObject<POINTER_OBJECT, UNKNOWN_SIZE>(map, |
| slot, |
| object, |
| object_size); |
| } |
| |
| |
| static inline void EvacuateByteArray(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| int object_size = reinterpret_cast<ByteArray*>(object)->ByteArraySize(); |
| EvacuateObject<DATA_OBJECT, UNKNOWN_SIZE>(map, slot, object, object_size); |
| } |
| |
| |
| static inline void EvacuateSeqAsciiString(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| int object_size = SeqAsciiString::cast(object)-> |
| SeqAsciiStringSize(map->instance_type()); |
| EvacuateObject<DATA_OBJECT, UNKNOWN_SIZE>(map, slot, object, object_size); |
| } |
| |
| |
| static inline void EvacuateSeqTwoByteString(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| int object_size = SeqTwoByteString::cast(object)-> |
| SeqTwoByteStringSize(map->instance_type()); |
| EvacuateObject<DATA_OBJECT, UNKNOWN_SIZE>(map, slot, object, object_size); |
| } |
| |
| |
| static inline bool IsShortcutCandidate(int type) { |
| return ((type & kShortcutTypeMask) == kShortcutTypeTag); |
| } |
| |
| static inline void EvacuateShortcutCandidate(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| ASSERT(IsShortcutCandidate(map->instance_type())); |
| |
| if (ConsString::cast(object)->unchecked_second() == Heap::empty_string()) { |
| HeapObject* first = |
| HeapObject::cast(ConsString::cast(object)->unchecked_first()); |
| |
| *slot = first; |
| |
| if (!Heap::InNewSpace(first)) { |
| object->set_map_word(MapWord::FromForwardingAddress(first)); |
| return; |
| } |
| |
| MapWord first_word = first->map_word(); |
| if (first_word.IsForwardingAddress()) { |
| HeapObject* target = first_word.ToForwardingAddress(); |
| |
| *slot = target; |
| object->set_map_word(MapWord::FromForwardingAddress(target)); |
| return; |
| } |
| |
| Scavenge(first->map(), slot, first); |
| object->set_map_word(MapWord::FromForwardingAddress(*slot)); |
| return; |
| } |
| |
| int object_size = ConsString::kSize; |
| EvacuateObject<POINTER_OBJECT, SMALL>(map, slot, object, object_size); |
| } |
| |
| template<ObjectContents object_contents> |
| class ObjectEvacuationStrategy { |
| public: |
| template<int object_size> |
| static inline void VisitSpecialized(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| EvacuateObject<object_contents, SMALL>(map, slot, object, object_size); |
| } |
| |
| static inline void Visit(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| int object_size = map->instance_size(); |
| EvacuateObject<object_contents, SMALL>(map, slot, object, object_size); |
| } |
| }; |
| |
| typedef void (*Callback)(Map* map, HeapObject** slot, HeapObject* object); |
| |
| static VisitorDispatchTable<Callback> table_; |
| }; |
| |
| |
| VisitorDispatchTable<ScavengingVisitor::Callback> ScavengingVisitor::table_; |
| |
| |
| void Heap::ScavengeObjectSlow(HeapObject** p, HeapObject* object) { |
| ASSERT(InFromSpace(object)); |
| MapWord first_word = object->map_word(); |
| ASSERT(!first_word.IsForwardingAddress()); |
| Map* map = first_word.ToMap(); |
| ScavengingVisitor::Scavenge(map, p, object); |
| } |
| |
| |
| void Heap::ScavengePointer(HeapObject** p) { |
| ScavengeObject(p, *p); |
| } |
| |
| |
| MaybeObject* Heap::AllocatePartialMap(InstanceType instance_type, |
| int instance_size) { |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRawMap(); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| // Map::cast cannot be used due to uninitialized map field. |
| reinterpret_cast<Map*>(result)->set_map(raw_unchecked_meta_map()); |
| reinterpret_cast<Map*>(result)->set_instance_type(instance_type); |
| reinterpret_cast<Map*>(result)->set_instance_size(instance_size); |
| reinterpret_cast<Map*>(result)-> |
| set_visitor_id( |
| StaticVisitorBase::GetVisitorId(instance_type, instance_size)); |
| reinterpret_cast<Map*>(result)->set_inobject_properties(0); |
| reinterpret_cast<Map*>(result)->set_pre_allocated_property_fields(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); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateMap(InstanceType instance_type, int instance_size) { |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRawMap(); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| Map* map = reinterpret_cast<Map*>(result); |
| map->set_map(meta_map()); |
| map->set_instance_type(instance_type); |
| map->set_visitor_id( |
| StaticVisitorBase::GetVisitorId(instance_type, instance_size)); |
| map->set_prototype(null_value()); |
| map->set_constructor(null_value()); |
| map->set_instance_size(instance_size); |
| map->set_inobject_properties(0); |
| map->set_pre_allocated_property_fields(0); |
| map->set_instance_descriptors(empty_descriptor_array()); |
| map->set_code_cache(empty_fixed_array()); |
| map->set_unused_property_fields(0); |
| map->set_bit_field(0); |
| map->set_bit_field2((1 << Map::kIsExtensible) | (1 << Map::kHasFastElements)); |
| |
| // If the map object is aligned fill the padding area with Smi 0 objects. |
| if (Map::kPadStart < Map::kSize) { |
| memset(reinterpret_cast<byte*>(map) + Map::kPadStart - kHeapObjectTag, |
| 0, |
| Map::kSize - Map::kPadStart); |
| } |
| return map; |
| } |
| |
| |
| MaybeObject* Heap::AllocateCodeCache() { |
| Object* result; |
| { MaybeObject* maybe_result = AllocateStruct(CODE_CACHE_TYPE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| CodeCache* code_cache = CodeCache::cast(result); |
| code_cache->set_default_cache(empty_fixed_array()); |
| code_cache->set_normal_type_cache(undefined_value()); |
| return code_cache; |
| } |
| |
| |
| 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::ConstantSymbolTable Heap::constant_symbol_table[] = { |
| #define CONSTANT_SYMBOL_ELEMENT(name, contents) \ |
| {contents, k##name##RootIndex}, |
| SYMBOL_LIST(CONSTANT_SYMBOL_ELEMENT) |
| #undef CONSTANT_SYMBOL_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 |
| }; |
| |
| |
| bool Heap::CreateInitialMaps() { |
| Object* obj; |
| { MaybeObject* maybe_obj = AllocatePartialMap(MAP_TYPE, Map::kSize); |
| if (!maybe_obj->ToObject(&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); |
| |
| { MaybeObject* maybe_obj = |
| AllocatePartialMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_fixed_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocatePartialMap(ODDBALL_TYPE, Oddball::kSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_oddball_map(Map::cast(obj)); |
| |
| // Allocate the empty array. |
| { MaybeObject* maybe_obj = AllocateEmptyFixedArray(); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_empty_fixed_array(FixedArray::cast(obj)); |
| |
| { MaybeObject* maybe_obj = Allocate(oddball_map(), OLD_DATA_SPACE); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_null_value(obj); |
| |
| // Allocate the empty descriptor array. |
| { MaybeObject* maybe_obj = AllocateEmptyFixedArray(); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_empty_descriptor_array(DescriptorArray::cast(obj)); |
| |
| // Fix the instance_descriptors for the existing maps. |
| meta_map()->set_instance_descriptors(empty_descriptor_array()); |
| meta_map()->set_code_cache(empty_fixed_array()); |
| |
| fixed_array_map()->set_instance_descriptors(empty_descriptor_array()); |
| fixed_array_map()->set_code_cache(empty_fixed_array()); |
| |
| oddball_map()->set_instance_descriptors(empty_descriptor_array()); |
| oddball_map()->set_code_cache(empty_fixed_array()); |
| |
| // Fix prototype object for existing maps. |
| meta_map()->set_prototype(null_value()); |
| meta_map()->set_constructor(null_value()); |
| |
| fixed_array_map()->set_prototype(null_value()); |
| fixed_array_map()->set_constructor(null_value()); |
| |
| oddball_map()->set_prototype(null_value()); |
| oddball_map()->set_constructor(null_value()); |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_fixed_cow_array_map(Map::cast(obj)); |
| ASSERT(fixed_array_map() != fixed_cow_array_map()); |
| |
| { MaybeObject* maybe_obj = AllocateMap(HEAP_NUMBER_TYPE, HeapNumber::kSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_heap_number_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(PROXY_TYPE, Proxy::kSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_proxy_map(Map::cast(obj)); |
| |
| for (unsigned i = 0; i < ARRAY_SIZE(string_type_table); i++) { |
| const StringTypeTable& entry = string_type_table[i]; |
| { MaybeObject* maybe_obj = AllocateMap(entry.type, entry.size); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| roots_[entry.index] = Map::cast(obj); |
| } |
| |
| { MaybeObject* maybe_obj = AllocateMap(STRING_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_undetectable_string_map(Map::cast(obj)); |
| Map::cast(obj)->set_is_undetectable(); |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(ASCII_STRING_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_undetectable_ascii_string_map(Map::cast(obj)); |
| Map::cast(obj)->set_is_undetectable(); |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(BYTE_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_byte_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateByteArray(0, TENURED); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_empty_byte_array(ByteArray::cast(obj)); |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(PIXEL_ARRAY_TYPE, PixelArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_pixel_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(EXTERNAL_BYTE_ARRAY_TYPE, |
| ExternalArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_external_byte_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE, |
| ExternalArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_external_unsigned_byte_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(EXTERNAL_SHORT_ARRAY_TYPE, |
| ExternalArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_external_short_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE, |
| ExternalArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_external_unsigned_short_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(EXTERNAL_INT_ARRAY_TYPE, |
| ExternalArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_external_int_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(EXTERNAL_UNSIGNED_INT_ARRAY_TYPE, |
| ExternalArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_external_unsigned_int_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(EXTERNAL_FLOAT_ARRAY_TYPE, |
| ExternalArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_external_float_array_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(CODE_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_code_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(JS_GLOBAL_PROPERTY_CELL_TYPE, |
| JSGlobalPropertyCell::kSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_global_property_cell_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(FILLER_TYPE, kPointerSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_one_pointer_filler_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(FILLER_TYPE, 2 * kPointerSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_two_pointer_filler_map(Map::cast(obj)); |
| |
| for (unsigned i = 0; i < ARRAY_SIZE(struct_table); i++) { |
| const StructTable& entry = struct_table[i]; |
| { MaybeObject* maybe_obj = AllocateMap(entry.type, entry.size); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| roots_[entry.index] = Map::cast(obj); |
| } |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_hash_table_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_context_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_catch_context_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| Map* global_context_map = Map::cast(obj); |
| global_context_map->set_visitor_id(StaticVisitorBase::kVisitGlobalContext); |
| set_global_context_map(global_context_map); |
| |
| { MaybeObject* maybe_obj = AllocateMap(SHARED_FUNCTION_INFO_TYPE, |
| SharedFunctionInfo::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_shared_function_info_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(JS_MESSAGE_OBJECT_TYPE, |
| JSMessageObject::kSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_message_object_map(Map::cast(obj)); |
| |
| ASSERT(!Heap::InNewSpace(Heap::empty_fixed_array())); |
| return true; |
| } |
| |
| |
| MaybeObject* Heap::AllocateHeapNumber(double value, PretenureFlag pretenure) { |
| // Statically ensure that it is safe to allocate heap numbers in paged |
| // spaces. |
| STATIC_ASSERT(HeapNumber::kSize <= Page::kMaxHeapObjectSize); |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateRaw(HeapNumber::kSize, space, OLD_DATA_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| HeapObject::cast(result)->set_map(heap_number_map()); |
| HeapNumber::cast(result)->set_value(value); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateHeapNumber(double value) { |
| // Use general version, if we're forced to always allocate. |
| if (always_allocate()) return AllocateHeapNumber(value, TENURED); |
| |
| // This version of AllocateHeapNumber is optimized for |
| // allocation in new space. |
| STATIC_ASSERT(HeapNumber::kSize <= Page::kMaxHeapObjectSize); |
| ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| Object* result; |
| { MaybeObject* maybe_result = new_space_.AllocateRaw(HeapNumber::kSize); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| HeapObject::cast(result)->set_map(heap_number_map()); |
| HeapNumber::cast(result)->set_value(value); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateJSGlobalPropertyCell(Object* value) { |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRawCell(); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| HeapObject::cast(result)->set_map(global_property_cell_map()); |
| JSGlobalPropertyCell::cast(result)->set_value(value); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::CreateOddball(const char* to_string, |
| Object* to_number) { |
| Object* result; |
| { MaybeObject* maybe_result = Allocate(oddball_map(), OLD_DATA_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| return Oddball::cast(result)->Initialize(to_string, to_number); |
| } |
| |
| |
| bool Heap::CreateApiObjects() { |
| Object* obj; |
| |
| { MaybeObject* maybe_obj = AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_neander_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = Heap::AllocateJSObjectFromMap(neander_map()); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| Object* elements; |
| { MaybeObject* maybe_elements = AllocateFixedArray(2); |
| if (!maybe_elements->ToObject(&elements)) return false; |
| } |
| FixedArray::cast(elements)->set(0, Smi::FromInt(0)); |
| JSObject::cast(obj)->set_elements(FixedArray::cast(elements)); |
| set_message_listeners(JSObject::cast(obj)); |
| |
| return true; |
| } |
| |
| |
| void Heap::CreateCEntryStub() { |
| CEntryStub stub(1); |
| set_c_entry_code(*stub.GetCode()); |
| } |
| |
| |
| #if V8_TARGET_ARCH_ARM && !V8_INTERPRETED_REGEXP |
| void Heap::CreateRegExpCEntryStub() { |
| RegExpCEntryStub stub; |
| set_re_c_entry_code(*stub.GetCode()); |
| } |
| #endif |
| |
| |
| void Heap::CreateJSEntryStub() { |
| JSEntryStub stub; |
| set_js_entry_code(*stub.GetCode()); |
| } |
| |
| |
| void Heap::CreateJSConstructEntryStub() { |
| JSConstructEntryStub stub; |
| set_js_construct_entry_code(*stub.GetCode()); |
| } |
| |
| |
| #if V8_TARGET_ARCH_ARM |
| void Heap::CreateDirectCEntryStub() { |
| DirectCEntryStub stub; |
| set_direct_c_entry_code(*stub.GetCode()); |
| } |
| #endif |
| |
| |
| 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; |
| // gcc-4.4 has problem generating correct code of following snippet: |
| // { CEntryStub stub; |
| // c_entry_code_ = *stub.GetCode(); |
| // } |
| // { DebuggerStatementStub stub; |
| // debugger_statement_code_ = *stub.GetCode(); |
| // } |
| // To workaround the problem, make separate functions without inlining. |
| Heap::CreateCEntryStub(); |
| Heap::CreateJSEntryStub(); |
| Heap::CreateJSConstructEntryStub(); |
| #if V8_TARGET_ARCH_ARM && !V8_INTERPRETED_REGEXP |
| Heap::CreateRegExpCEntryStub(); |
| #endif |
| #if V8_TARGET_ARCH_ARM |
| Heap::CreateDirectCEntryStub(); |
| #endif |
| } |
| |
| |
| bool Heap::CreateInitialObjects() { |
| Object* obj; |
| |
| // The -0 value must be set before NumberFromDouble works. |
| { MaybeObject* maybe_obj = AllocateHeapNumber(-0.0, TENURED); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_minus_zero_value(obj); |
| ASSERT(signbit(minus_zero_value()->Number()) != 0); |
| |
| { MaybeObject* maybe_obj = AllocateHeapNumber(OS::nan_value(), TENURED); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_nan_value(obj); |
| |
| { MaybeObject* maybe_obj = Allocate(oddball_map(), OLD_DATA_SPACE); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_undefined_value(obj); |
| ASSERT(!InNewSpace(undefined_value())); |
| |
| // Allocate initial symbol table. |
| { MaybeObject* maybe_obj = SymbolTable::Allocate(kInitialSymbolTableSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| // Don't use set_symbol_table() due to asserts. |
| roots_[kSymbolTableRootIndex] = obj; |
| |
| // Assign the print strings for oddballs after creating symboltable. |
| Object* symbol; |
| { MaybeObject* maybe_symbol = LookupAsciiSymbol("undefined"); |
| if (!maybe_symbol->ToObject(&symbol)) return false; |
| } |
| Oddball::cast(undefined_value())->set_to_string(String::cast(symbol)); |
| Oddball::cast(undefined_value())->set_to_number(nan_value()); |
| |
| // Allocate the null_value |
| { MaybeObject* maybe_obj = |
| Oddball::cast(null_value())->Initialize("null", Smi::FromInt(0)); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| |
| { MaybeObject* maybe_obj = CreateOddball("true", Smi::FromInt(1)); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_true_value(obj); |
| |
| { MaybeObject* maybe_obj = CreateOddball("false", Smi::FromInt(0)); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_false_value(obj); |
| |
| { MaybeObject* maybe_obj = CreateOddball("hole", Smi::FromInt(-1)); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_the_hole_value(obj); |
| |
| { MaybeObject* maybe_obj = CreateOddball("arguments_marker", |
| Smi::FromInt(-4)); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_arguments_marker(obj); |
| |
| { MaybeObject* maybe_obj = |
| CreateOddball("no_interceptor_result_sentinel", Smi::FromInt(-2)); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_no_interceptor_result_sentinel(obj); |
| |
| { MaybeObject* maybe_obj = |
| CreateOddball("termination_exception", Smi::FromInt(-3)); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_termination_exception(obj); |
| |
| // Allocate the empty string. |
| { MaybeObject* maybe_obj = AllocateRawAsciiString(0, TENURED); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_empty_string(String::cast(obj)); |
| |
| for (unsigned i = 0; i < ARRAY_SIZE(constant_symbol_table); i++) { |
| { MaybeObject* maybe_obj = |
| LookupAsciiSymbol(constant_symbol_table[i].contents); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| roots_[constant_symbol_table[i].index] = String::cast(obj); |
| } |
| |
| // Allocate the hidden symbol which is used to identify the hidden properties |
| // in JSObjects. The hash code has a special value so that it will not match |
| // the empty string when searching for the property. It cannot be part of the |
| // loop above because it needs to be allocated manually with the special |
| // hash code in place. The hash code for the hidden_symbol is zero to ensure |
| // that it will always be at the first entry in property descriptors. |
| { MaybeObject* maybe_obj = |
| AllocateSymbol(CStrVector(""), 0, String::kZeroHash); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| hidden_symbol_ = String::cast(obj); |
| |
| // Allocate the proxy for __proto__. |
| { MaybeObject* maybe_obj = |
| AllocateProxy((Address) &Accessors::ObjectPrototype); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_prototype_accessors(Proxy::cast(obj)); |
| |
| // Allocate the code_stubs dictionary. The initial size is set to avoid |
| // expanding the dictionary during bootstrapping. |
| { MaybeObject* maybe_obj = NumberDictionary::Allocate(128); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_code_stubs(NumberDictionary::cast(obj)); |
| |
| // Allocate the non_monomorphic_cache used in stub-cache.cc. The initial size |
| // is set to avoid expanding the dictionary during bootstrapping. |
| { MaybeObject* maybe_obj = NumberDictionary::Allocate(64); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_non_monomorphic_cache(NumberDictionary::cast(obj)); |
| |
| set_instanceof_cache_function(Smi::FromInt(0)); |
| set_instanceof_cache_map(Smi::FromInt(0)); |
| set_instanceof_cache_answer(Smi::FromInt(0)); |
| |
| CreateFixedStubs(); |
| |
| // Allocate the dictionary of intrinsic function names. |
| { MaybeObject* maybe_obj = StringDictionary::Allocate(Runtime::kNumFunctions); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| { MaybeObject* maybe_obj = Runtime::InitializeIntrinsicFunctionNames(obj); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_intrinsic_function_names(StringDictionary::cast(obj)); |
| |
| if (InitializeNumberStringCache()->IsFailure()) return false; |
| |
| // Allocate cache for single character ASCII strings. |
| { MaybeObject* maybe_obj = |
| AllocateFixedArray(String::kMaxAsciiCharCode + 1, TENURED); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_single_character_string_cache(FixedArray::cast(obj)); |
| |
| // Allocate cache for external strings pointing to native source code. |
| { MaybeObject* maybe_obj = AllocateFixedArray(Natives::GetBuiltinsCount()); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_natives_source_cache(FixedArray::cast(obj)); |
| |
| // Handling of script id generation is in Factory::NewScript. |
| set_last_script_id(undefined_value()); |
| |
| // Initialize keyed lookup cache. |
| KeyedLookupCache::Clear(); |
| |
| // Initialize context slot cache. |
| ContextSlotCache::Clear(); |
| |
| // Initialize descriptor cache. |
| DescriptorLookupCache::Clear(); |
| |
| // Initialize compilation cache. |
| CompilationCache::Clear(); |
| |
| return true; |
| } |
| |
| |
| MaybeObject* Heap::InitializeNumberStringCache() { |
| // Compute the size of the number string cache based on the max heap size. |
| // max_semispace_size_ == 512 KB => number_string_cache_size = 32. |
| // max_semispace_size_ == 8 MB => number_string_cache_size = 16KB. |
| int number_string_cache_size = max_semispace_size_ / 512; |
| number_string_cache_size = Max(32, Min(16*KB, number_string_cache_size)); |
| Object* obj; |
| MaybeObject* maybe_obj = |
| AllocateFixedArray(number_string_cache_size * 2, TENURED); |
| if (maybe_obj->ToObject(&obj)) set_number_string_cache(FixedArray::cast(obj)); |
| return maybe_obj; |
| } |
| |
| |
| 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); |
| } |
| } |
| |
| |
| static inline int double_get_hash(double d) { |
| DoubleRepresentation rep(d); |
| return static_cast<int>(rep.bits) ^ static_cast<int>(rep.bits >> 32); |
| } |
| |
| |
| static inline int smi_get_hash(Smi* smi) { |
| return smi->value(); |
| } |
| |
| |
| Object* Heap::GetNumberStringCache(Object* number) { |
| int hash; |
| int mask = (number_string_cache()->length() >> 1) - 1; |
| if (number->IsSmi()) { |
| hash = smi_get_hash(Smi::cast(number)) & mask; |
| } else { |
| hash = double_get_hash(number->Number()) & mask; |
| } |
| Object* key = number_string_cache()->get(hash * 2); |
| if (key == number) { |
| return String::cast(number_string_cache()->get(hash * 2 + 1)); |
| } else if (key->IsHeapNumber() && |
| number->IsHeapNumber() && |
| key->Number() == number->Number()) { |
| return String::cast(number_string_cache()->get(hash * 2 + 1)); |
| } |
| return undefined_value(); |
| } |
| |
| |
| void Heap::SetNumberStringCache(Object* number, String* string) { |
| int hash; |
| int mask = (number_string_cache()->length() >> 1) - 1; |
| if (number->IsSmi()) { |
| hash = smi_get_hash(Smi::cast(number)) & mask; |
| number_string_cache()->set(hash * 2, Smi::cast(number)); |
| } else { |
| hash = double_get_hash(number->Number()) & mask; |
| number_string_cache()->set(hash * 2, number); |
| } |
| number_string_cache()->set(hash * 2 + 1, string); |
| } |
| |
| |
| MaybeObject* Heap::NumberToString(Object* number, |
| bool check_number_string_cache) { |
| Counters::number_to_string_runtime.Increment(); |
| if (check_number_string_cache) { |
| Object* cached = GetNumberStringCache(number); |
| if (cached != undefined_value()) { |
| return cached; |
| } |
| } |
| |
| char arr[100]; |
| Vector<char> buffer(arr, ARRAY_SIZE(arr)); |
| const char* str; |
| if (number->IsSmi()) { |
| int num = Smi::cast(number)->value(); |
| str = IntToCString(num, buffer); |
| } else { |
| double num = HeapNumber::cast(number)->value(); |
| str = DoubleToCString(num, buffer); |
| } |
| |
| Object* js_string; |
| MaybeObject* maybe_js_string = AllocateStringFromAscii(CStrVector(str)); |
| if (maybe_js_string->ToObject(&js_string)) { |
| SetNumberStringCache(number, String::cast(js_string)); |
| } |
| return maybe_js_string; |
| } |
| |
| |
| Map* Heap::MapForExternalArrayType(ExternalArrayType array_type) { |
| return Map::cast(roots_[RootIndexForExternalArrayType(array_type)]); |
| } |
| |
| |
| Heap::RootListIndex Heap::RootIndexForExternalArrayType( |
| ExternalArrayType array_type) { |
| switch (array_type) { |
| case kExternalByteArray: |
| return kExternalByteArrayMapRootIndex; |
| case kExternalUnsignedByteArray: |
| return kExternalUnsignedByteArrayMapRootIndex; |
| case kExternalShortArray: |
| return kExternalShortArrayMapRootIndex; |
| case kExternalUnsignedShortArray: |
| return kExternalUnsignedShortArrayMapRootIndex; |
| case kExternalIntArray: |
| return kExternalIntArrayMapRootIndex; |
| case kExternalUnsignedIntArray: |
| return kExternalUnsignedIntArrayMapRootIndex; |
| case kExternalFloatArray: |
| return kExternalFloatArrayMapRootIndex; |
| default: |
| UNREACHABLE(); |
| return kUndefinedValueRootIndex; |
| } |
| } |
| |
| |
| MaybeObject* Heap::NumberFromDouble(double value, PretenureFlag pretenure) { |
| // We need to distinguish the minus zero value and this cannot be |
| // done after conversion to int. Doing this by comparing bit |
| // patterns is faster than using fpclassify() et al. |
| static const DoubleRepresentation minus_zero(-0.0); |
| |
| DoubleRepresentation rep(value); |
| if (rep.bits == minus_zero.bits) { |
| return AllocateHeapNumber(-0.0, pretenure); |
| } |
| |
| int int_value = FastD2I(value); |
| if (value == int_value && Smi::IsValid(int_value)) { |
| return Smi::FromInt(int_value); |
| } |
| |
| // Materialize the value in the heap. |
| return AllocateHeapNumber(value, pretenure); |
| } |
| |
| |
| MaybeObject* Heap::AllocateProxy(Address proxy, PretenureFlag pretenure) { |
| // Statically ensure that it is safe to allocate proxies in paged spaces. |
| STATIC_ASSERT(Proxy::kSize <= Page::kMaxHeapObjectSize); |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| Object* result; |
| { MaybeObject* maybe_result = Allocate(proxy_map(), space); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| Proxy::cast(result)->set_proxy(proxy); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateSharedFunctionInfo(Object* name) { |
| Object* result; |
| { MaybeObject* maybe_result = |
| Allocate(shared_function_info_map(), OLD_POINTER_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| SharedFunctionInfo* share = SharedFunctionInfo::cast(result); |
| share->set_name(name); |
| Code* illegal = Builtins::builtin(Builtins::Illegal); |
| share->set_code(illegal); |
| share->set_scope_info(SerializedScopeInfo::Empty()); |
| Code* construct_stub = Builtins::builtin(Builtins::JSConstructStubGeneric); |
| share->set_construct_stub(construct_stub); |
| share->set_expected_nof_properties(0); |
| share->set_length(0); |
| share->set_formal_parameter_count(0); |
| share->set_instance_class_name(Object_symbol()); |
| share->set_function_data(undefined_value()); |
| share->set_script(undefined_value()); |
| share->set_start_position_and_type(0); |
| share->set_debug_info(undefined_value()); |
| share->set_inferred_name(empty_string()); |
| share->set_compiler_hints(0); |
| share->set_deopt_counter(Smi::FromInt(FLAG_deopt_every_n_times)); |
| share->set_initial_map(undefined_value()); |
| share->set_this_property_assignments_count(0); |
| share->set_this_property_assignments(undefined_value()); |
| share->set_opt_count(0); |
| share->set_num_literals(0); |
| share->set_end_position(0); |
| share->set_function_token_position(0); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateJSMessageObject(String* type, |
| JSArray* arguments, |
| int start_position, |
| int end_position, |
| Object* script, |
| Object* stack_trace, |
| Object* stack_frames) { |
| Object* result; |
| { MaybeObject* maybe_result = Allocate(message_object_map(), NEW_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| JSMessageObject* message = JSMessageObject::cast(result); |
| message->set_properties(Heap::empty_fixed_array()); |
| message->set_elements(Heap::empty_fixed_array()); |
| message->set_type(type); |
| message->set_arguments(arguments); |
| message->set_start_position(start_position); |
| message->set_end_position(end_position); |
| message->set_script(script); |
| message->set_stack_trace(stack_trace); |
| message->set_stack_frames(stack_frames); |
| return result; |
| } |
| |
| |
| |
| // Returns true for a character in a range. Both limits are inclusive. |
| static inline bool Between(uint32_t character, uint32_t from, uint32_t to) { |
| // This makes uses of the the unsigned wraparound. |
| return character - from <= to - from; |
| } |
| |
| |
| MUST_USE_RESULT static inline MaybeObject* MakeOrFindTwoCharacterString( |
| uint32_t c1, |
| uint32_t c2) { |
| String* symbol; |
| // Numeric strings have a different hash algorithm not known by |
| // LookupTwoCharsSymbolIfExists, so we skip this step for such strings. |
| if ((!Between(c1, '0', '9') || !Between(c2, '0', '9')) && |
| Heap::symbol_table()->LookupTwoCharsSymbolIfExists(c1, c2, &symbol)) { |
| return symbol; |
| // Now we know the length is 2, we might as well make use of that fact |
| // when building the new string. |
| } else if ((c1 | c2) <= String::kMaxAsciiCharCodeU) { // We can do this |
| ASSERT(IsPowerOf2(String::kMaxAsciiCharCodeU + 1)); // because of this. |
| Object* result; |
| { MaybeObject* maybe_result = Heap::AllocateRawAsciiString(2); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| char* dest = SeqAsciiString::cast(result)->GetChars(); |
| dest[0] = c1; |
| dest[1] = c2; |
| return result; |
| } else { |
| Object* result; |
| { MaybeObject* maybe_result = Heap::AllocateRawTwoByteString(2); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| uc16* dest = SeqTwoByteString::cast(result)->GetChars(); |
| dest[0] = c1; |
| dest[1] = c2; |
| return result; |
| } |
| } |
| |
| |
| MaybeObject* Heap::AllocateConsString(String* first, String* second) { |
| int first_length = first->length(); |
| if (first_length == 0) { |
| return second; |
| } |
| |
| int second_length = second->length(); |
| if (second_length == 0) { |
| return first; |
| } |
| |
| int length = first_length + second_length; |
| |
| // Optimization for 2-byte strings often used as keys in a decompression |
| // dictionary. Check whether we already have the string in the symbol |
| // table to prevent creation of many unneccesary strings. |
| if (length == 2) { |
| unsigned c1 = first->Get(0); |
| unsigned c2 = second->Get(0); |
| return MakeOrFindTwoCharacterString(c1, c2); |
| } |
| |
| bool first_is_ascii = first->IsAsciiRepresentation(); |
| bool second_is_ascii = second->IsAsciiRepresentation(); |
| bool is_ascii = first_is_ascii && second_is_ascii; |
| |
| // Make sure that an out of memory exception is thrown if the length |
| // of the new cons string is too large. |
| if (length > String::kMaxLength || length < 0) { |
| Top::context()->mark_out_of_memory(); |
| return Failure::OutOfMemoryException(); |
| } |
| |
| bool is_ascii_data_in_two_byte_string = false; |
| if (!is_ascii) { |
| // At least one of the strings uses two-byte representation so we |
| // can't use the fast case code for short ascii strings below, but |
| // we can try to save memory if all chars actually fit in ascii. |
| is_ascii_data_in_two_byte_string = |
| first->HasOnlyAsciiChars() && second->HasOnlyAsciiChars(); |
| if (is_ascii_data_in_two_byte_string) { |
| Counters::string_add_runtime_ext_to_ascii.Increment(); |
| } |
| } |
| |
| // If the resulting string is small make a flat string. |
| if (length < String::kMinNonFlatLength) { |
| ASSERT(first->IsFlat()); |
| ASSERT(second->IsFlat()); |
| if (is_ascii) { |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRawAsciiString(length); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| // Copy the characters into the new object. |
| char* dest = SeqAsciiString::cast(result)->GetChars(); |
| // Copy first part. |
| const char* src; |
| if (first->IsExternalString()) { |
| src = ExternalAsciiString::cast(first)->resource()->data(); |
| } else { |
| src = SeqAsciiString::cast(first)->GetChars(); |
| } |
| for (int i = 0; i < first_length; i++) *dest++ = src[i]; |
| // Copy second part. |
| if (second->IsExternalString()) { |
| src = ExternalAsciiString::cast(second)->resource()->data(); |
| } else { |
| src = SeqAsciiString::cast(second)->GetChars(); |
| } |
| for (int i = 0; i < second_length; i++) *dest++ = src[i]; |
| return result; |
| } else { |
| if (is_ascii_data_in_two_byte_string) { |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRawAsciiString(length); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| // Copy the characters into the new object. |
| char* dest = SeqAsciiString::cast(result)->GetChars(); |
| String::WriteToFlat(first, dest, 0, first_length); |
| String::WriteToFlat(second, dest + first_length, 0, second_length); |
| return result; |
| } |
| |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRawTwoByteString(length); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| // Copy the characters into the new object. |
| uc16* dest = SeqTwoByteString::cast(result)->GetChars(); |
| String::WriteToFlat(first, dest, 0, first_length); |
| String::WriteToFlat(second, dest + first_length, 0, second_length); |
| return result; |
| } |
| } |
| |
| Map* map = (is_ascii || is_ascii_data_in_two_byte_string) ? |
| cons_ascii_string_map() : cons_string_map(); |
| |
| Object* result; |
| { MaybeObject* maybe_result = Allocate(map, NEW_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| AssertNoAllocation no_gc; |
| ConsString* cons_string = ConsString::cast(result); |
| WriteBarrierMode mode = cons_string->GetWriteBarrierMode(no_gc); |
| cons_string->set_length(length); |
| cons_string->set_hash_field(String::kEmptyHashField); |
| cons_string->set_first(first, mode); |
| cons_string->set_second(second, mode); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateSubString(String* buffer, |
| int start, |
| int end, |
| PretenureFlag pretenure) { |
| int length = end - start; |
| |
| if (length == 1) { |
| return Heap::LookupSingleCharacterStringFromCode( |
| buffer->Get(start)); |
| } else if (length == 2) { |
| // Optimization for 2-byte strings often used as keys in a decompression |
| // dictionary. Check whether we already have the string in the symbol |
| // table to prevent creation of many unneccesary strings. |
| unsigned c1 = buffer->Get(start); |
| unsigned c2 = buffer->Get(start + 1); |
| return MakeOrFindTwoCharacterString(c1, c2); |
| } |
| |
| // Make an attempt to flatten the buffer to reduce access time. |
| buffer = buffer->TryFlattenGetString(); |
| |
| Object* result; |
| { MaybeObject* maybe_result = buffer->IsAsciiRepresentation() |
| ? AllocateRawAsciiString(length, pretenure ) |
| : AllocateRawTwoByteString(length, pretenure); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| String* string_result = String::cast(result); |
| // Copy the characters into the new object. |
| if (buffer->IsAsciiRepresentation()) { |
| ASSERT(string_result->IsAsciiRepresentation()); |
| char* dest = SeqAsciiString::cast(string_result)->GetChars(); |
| String::WriteToFlat(buffer, dest, start, end); |
| } else { |
| ASSERT(string_result->IsTwoByteRepresentation()); |
| uc16* dest = SeqTwoByteString::cast(string_result)->GetChars(); |
| String::WriteToFlat(buffer, dest, start, end); |
| } |
| |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateExternalStringFromAscii( |
| ExternalAsciiString::Resource* resource) { |
| size_t length = resource->length(); |
| if (length > static_cast<size_t>(String::kMaxLength)) { |
| Top::context()->mark_out_of_memory(); |
| return Failure::OutOfMemoryException(); |
| } |
| |
| Map* map = external_ascii_string_map(); |
| Object* result; |
| { MaybeObject* maybe_result = Allocate(map, NEW_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| ExternalAsciiString* external_string = ExternalAsciiString::cast(result); |
| external_string->set_length(static_cast<int>(length)); |
| external_string->set_hash_field(String::kEmptyHashField); |
| external_string->set_resource(resource); |
| |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateExternalStringFromTwoByte( |
| ExternalTwoByteString::Resource* resource) { |
| size_t length = resource->length(); |
| if (length > static_cast<size_t>(String::kMaxLength)) { |
| Top::context()->mark_out_of_memory(); |
| return Failure::OutOfMemoryException(); |
| } |
| |
| // For small strings we check whether the resource contains only |
| // ASCII characters. If yes, we use a different string map. |
| static const size_t kAsciiCheckLengthLimit = 32; |
| bool is_ascii = length <= kAsciiCheckLengthLimit && |
| String::IsAscii(resource->data(), static_cast<int>(length)); |
| Map* map = is_ascii ? |
| Heap::external_string_with_ascii_data_map() : Heap::external_string_map(); |
| Object* result; |
| { MaybeObject* maybe_result = Allocate(map, NEW_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| ExternalTwoByteString* external_string = ExternalTwoByteString::cast(result); |
| external_string->set_length(static_cast<int>(length)); |
| external_string->set_hash_field(String::kEmptyHashField); |
| external_string->set_resource(resource); |
| |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::LookupSingleCharacterStringFromCode(uint16_t code) { |
| if (code <= String::kMaxAsciiCharCode) { |
| Object* value = Heap::single_character_string_cache()->get(code); |
| if (value != Heap::undefined_value()) return value; |
| |
| char buffer[1]; |
| buffer[0] = static_cast<char>(code); |
| Object* result; |
| MaybeObject* maybe_result = LookupSymbol(Vector<const char>(buffer, 1)); |
| |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| Heap::single_character_string_cache()->set(code, result); |
| return result; |
| } |
| |
| Object* result; |
| { MaybeObject* maybe_result = Heap::AllocateRawTwoByteString(1); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| String* answer = String::cast(result); |
| answer->Set(0, code); |
| return answer; |
| } |
| |
| |
| MaybeObject* Heap::AllocateByteArray(int length, PretenureFlag pretenure) { |
| if (length < 0 || length > ByteArray::kMaxLength) { |
| return Failure::OutOfMemoryException(); |
| } |
| if (pretenure == NOT_TENURED) { |
| return AllocateByteArray(length); |
| } |
| int size = ByteArray::SizeFor(length); |
| Object* result; |
| { MaybeObject* maybe_result = (size <= MaxObjectSizeInPagedSpace()) |
| ? old_data_space_->AllocateRaw(size) |
| : lo_space_->AllocateRaw(size); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| reinterpret_cast<ByteArray*>(result)->set_map(byte_array_map()); |
| reinterpret_cast<ByteArray*>(result)->set_length(length); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateByteArray(int length) { |
| if (length < 0 || length > ByteArray::kMaxLength) { |
| return Failure::OutOfMemoryException(); |
| } |
| int size = ByteArray::SizeFor(length); |
| AllocationSpace space = |
| (size > MaxObjectSizeInPagedSpace()) ? LO_SPACE : NEW_SPACE; |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRaw(size, space, OLD_DATA_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| reinterpret_cast<ByteArray*>(result)->set_map(byte_array_map()); |
| reinterpret_cast<ByteArray*>(result)->set_length(length); |
| return result; |
| } |
| |
| |
| void Heap::CreateFillerObjectAt(Address addr, int size) { |
| if (size == 0) return; |
| HeapObject* filler = HeapObject::FromAddress(addr); |
| if (size == kPointerSize) { |
| filler->set_map(one_pointer_filler_map()); |
| } else if (size == 2 * kPointerSize) { |
| filler->set_map(two_pointer_filler_map()); |
| } else { |
| filler->set_map(byte_array_map()); |
| ByteArray::cast(filler)->set_length(ByteArray::LengthFor(size)); |
| } |
| } |
| |
| |
| MaybeObject* Heap::AllocatePixelArray(int length, |
| uint8_t* external_pointer, |
| PretenureFlag pretenure) { |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateRaw(PixelArray::kAlignedSize, space, OLD_DATA_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| reinterpret_cast<PixelArray*>(result)->set_map(pixel_array_map()); |
| reinterpret_cast<PixelArray*>(result)->set_length(length); |
| reinterpret_cast<PixelArray*>(result)->set_external_pointer(external_pointer); |
| |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateExternalArray(int length, |
| ExternalArrayType array_type, |
| void* external_pointer, |
| PretenureFlag pretenure) { |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRaw(ExternalArray::kAlignedSize, |
| space, |
| OLD_DATA_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| reinterpret_cast<ExternalArray*>(result)->set_map( |
| MapForExternalArrayType(array_type)); |
| reinterpret_cast<ExternalArray*>(result)->set_length(length); |
| reinterpret_cast<ExternalArray*>(result)->set_external_pointer( |
| external_pointer); |
| |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::CreateCode(const CodeDesc& desc, |
| Code::Flags flags, |
| Handle<Object> self_reference) { |
| // Allocate ByteArray before the Code object, so that we do not risk |
| // leaving uninitialized Code object (and breaking the heap). |
| Object* reloc_info; |
| { MaybeObject* maybe_reloc_info = AllocateByteArray(desc.reloc_size, TENURED); |
| if (!maybe_reloc_info->ToObject(&reloc_info)) return maybe_reloc_info; |
| } |
| |
| // Compute size |
| int body_size = RoundUp(desc.instr_size, kObjectAlignment); |
| int obj_size = Code::SizeFor(body_size); |
| ASSERT(IsAligned(static_cast<intptr_t>(obj_size), kCodeAlignment)); |
| MaybeObject* maybe_result; |
| if (obj_size > MaxObjectSizeInPagedSpace()) { |
| maybe_result = lo_space_->AllocateRawCode(obj_size); |
| } else { |
| maybe_result = code_space_->AllocateRaw(obj_size); |
| } |
| |
| Object* result; |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| |
| // Initialize the object |
| HeapObject::cast(result)->set_map(code_map()); |
| Code* code = Code::cast(result); |
| ASSERT(!CodeRange::exists() || CodeRange::contains(code->address())); |
| code->set_instruction_size(desc.instr_size); |
| code->set_relocation_info(ByteArray::cast(reloc_info)); |
| code->set_flags(flags); |
| if (code->is_call_stub() || code->is_keyed_call_stub()) { |
| code->set_check_type(RECEIVER_MAP_CHECK); |
| } |
| code->set_deoptimization_data(empty_fixed_array()); |
| // Allow self references to created code object by patching the handle to |
| // point to the newly allocated Code object. |
| if (!self_reference.is_null()) { |
| *(self_reference.location()) = code; |
| } |
| // Migrate generated code. |
| // The generated code can contain Object** values (typically from handles) |
| // that are dereferenced during the copy to point directly to the actual heap |
| // objects. These pointers can include references to the code object itself, |
| // through the self_reference parameter. |
| code->CopyFrom(desc); |
| |
| #ifdef DEBUG |
| code->Verify(); |
| #endif |
| return code; |
| } |
| |
| |
| MaybeObject* Heap::CopyCode(Code* code) { |
| // Allocate an object the same size as the code object. |
| int obj_size = code->Size(); |
| MaybeObject* maybe_result; |
| if (obj_size > MaxObjectSizeInPagedSpace()) { |
| maybe_result = lo_space_->AllocateRawCode(obj_size); |
| } else { |
| maybe_result = code_space_->AllocateRaw(obj_size); |
| } |
| |
| Object* result; |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| |
| // Copy code object. |
| Address old_addr = code->address(); |
| Address new_addr = reinterpret_cast<HeapObject*>(result)->address(); |
| CopyBlock(new_addr, old_addr, obj_size); |
| // Relocate the copy. |
| Code* new_code = Code::cast(result); |
| ASSERT(!CodeRange::exists() || CodeRange::contains(code->address())); |
| new_code->Relocate(new_addr - old_addr); |
| return new_code; |
| } |
| |
| |
| MaybeObject* 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). |
| Object* reloc_info_array; |
| { MaybeObject* maybe_reloc_info_array = |
| AllocateByteArray(reloc_info.length(), TENURED); |
| if (!maybe_reloc_info_array->ToObject(&reloc_info_array)) { |
| return maybe_reloc_info_array; |
| } |
| } |
| |
| 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); |
| |
| MaybeObject* maybe_result; |
| if (new_obj_size > MaxObjectSizeInPagedSpace()) { |
| maybe_result = lo_space_->AllocateRawCode(new_obj_size); |
| } else { |
| maybe_result = code_space_->AllocateRaw(new_obj_size); |
| } |
| |
| Object* result; |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| |
| // Copy code object. |
| Address new_addr = reinterpret_cast<HeapObject*>(result)->address(); |
| |
| // Copy header and instructions. |
| memcpy(new_addr, old_addr, relocation_offset); |
| |
| Code* new_code = Code::cast(result); |
| new_code->set_relocation_info(ByteArray::cast(reloc_info_array)); |
| |
| // Copy patched rinfo. |
| memcpy(new_code->relocation_start(), reloc_info.start(), reloc_info.length()); |
| |
| // Relocate the copy. |
| ASSERT(!CodeRange::exists() || CodeRange::contains(code->address())); |
| new_code->Relocate(new_addr - old_addr); |
| |
| #ifdef DEBUG |
| code->Verify(); |
| #endif |
| return new_code; |
| } |
| |
| |
| MaybeObject* Heap::Allocate(Map* map, AllocationSpace space) { |
| ASSERT(gc_state_ == NOT_IN_GC); |
| ASSERT(map->instance_type() != MAP_TYPE); |
| // If allocation failures are disallowed, we may allocate in a different |
| // space when new space is full and the object is not a large object. |
| AllocationSpace retry_space = |
| (space != NEW_SPACE) ? space : TargetSpaceId(map->instance_type()); |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateRaw(map->instance_size(), space, retry_space); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| HeapObject::cast(result)->set_map(map); |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| ProducerHeapProfile::RecordJSObjectAllocation(result); |
| #endif |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::InitializeFunction(JSFunction* function, |
| SharedFunctionInfo* shared, |
| Object* prototype) { |
| ASSERT(!prototype->IsMap()); |
| function->initialize_properties(); |
| function->initialize_elements(); |
| function->set_shared(shared); |
| function->set_code(shared->code()); |
| function->set_prototype_or_initial_map(prototype); |
| function->set_context(undefined_value()); |
| function->set_literals(empty_fixed_array()); |
| function->set_next_function_link(undefined_value()); |
| return function; |
| } |
| |
| |
| MaybeObject* Heap::AllocateFunctionPrototype(JSFunction* function) { |
| // Allocate the prototype. Make sure to use the object function |
| // from the function's context, since the function can be from a |
| // different context. |
| JSFunction* object_function = |
| function->context()->global_context()->object_function(); |
| Object* prototype; |
| { MaybeObject* maybe_prototype = AllocateJSObject(object_function); |
| if (!maybe_prototype->ToObject(&prototype)) return maybe_prototype; |
| } |
| // When creating the prototype for the function we must set its |
| // constructor to the function. |
| Object* result; |
| { MaybeObject* maybe_result = |
| JSObject::cast(prototype)->SetLocalPropertyIgnoreAttributes( |
| constructor_symbol(), function, DONT_ENUM); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| return prototype; |
| } |
| |
| |
| MaybeObject* Heap::AllocateFunction(Map* function_map, |
| SharedFunctionInfo* shared, |
| Object* prototype, |
| PretenureFlag pretenure) { |
| AllocationSpace space = |
| (pretenure == TENURED) ? OLD_POINTER_SPACE : NEW_SPACE; |
| Object* result; |
| { MaybeObject* maybe_result = Allocate(function_map, space); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| return InitializeFunction(JSFunction::cast(result), shared, prototype); |
| } |
| |
| |
| MaybeObject* Heap::AllocateArgumentsObject(Object* callee, int length) { |
| // To get fast allocation and map sharing for arguments objects we |
| // allocate them based on an arguments boilerplate. |
| |
| // This calls Copy directly rather than using Heap::AllocateRaw so we |
| // duplicate the check here. |
| ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| |
| JSObject* boilerplate = |
| Top::context()->global_context()->arguments_boilerplate(); |
| |
| // Check that the size of the boilerplate matches our |
| // expectations. The ArgumentsAccessStub::GenerateNewObject relies |
| // on the size being a known constant. |
| ASSERT(kArgumentsObjectSize == boilerplate->map()->instance_size()); |
| |
| // Do the allocation. |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateRaw(kArgumentsObjectSize, NEW_SPACE, OLD_POINTER_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| // Copy the content. The arguments boilerplate doesn't have any |
| // fields that point to new space so it's safe to skip the write |
| // barrier here. |
| CopyBlock(HeapObject::cast(result)->address(), |
| boilerplate->address(), |
| kArgumentsObjectSize); |
| |
| // Set the two properties. |
| JSObject::cast(result)->InObjectPropertyAtPut(arguments_callee_index, |
| callee); |
| JSObject::cast(result)->InObjectPropertyAtPut(arguments_length_index, |
| Smi::FromInt(length), |
| SKIP_WRITE_BARRIER); |
| |
| // Check the state of the object |
| ASSERT(JSObject::cast(result)->HasFastProperties()); |
| ASSERT(JSObject::cast(result)->HasFastElements()); |
| |
| return result; |
| } |
| |
| |
| static bool HasDuplicates(DescriptorArray* descriptors) { |
| int count = descriptors->number_of_descriptors(); |
| if (count > 1) { |
| String* prev_key = descriptors->GetKey(0); |
| for (int i = 1; i != count; i++) { |
| String* current_key = descriptors->GetKey(i); |
| if (prev_key == current_key) return true; |
| prev_key = current_key; |
| } |
| } |
| return false; |
| } |
| |
| |
| MaybeObject* Heap::AllocateInitialMap(JSFunction* fun) { |
| ASSERT(!fun->has_initial_map()); |
| |
| // First create a new map with the size and number of in-object properties |
| // suggested by the function. |
| int instance_size = fun->shared()->CalculateInstanceSize(); |
| int in_object_properties = fun->shared()->CalculateInObjectProperties(); |
| Object* map_obj; |
| { MaybeObject* maybe_map_obj = |
| Heap::AllocateMap(JS_OBJECT_TYPE, instance_size); |
| if (!maybe_map_obj->ToObject(&map_obj)) return maybe_map_obj; |
| } |
| |
| // Fetch or allocate prototype. |
| Object* prototype; |
| if (fun->has_instance_prototype()) { |
| prototype = fun->instance_prototype(); |
| } else { |
| { MaybeObject* maybe_prototype = AllocateFunctionPrototype(fun); |
| if (!maybe_prototype->ToObject(&prototype)) return maybe_prototype; |
| } |
| } |
| Map* map = Map::cast(map_obj); |
| map->set_inobject_properties(in_object_properties); |
| map->set_unused_property_fields(in_object_properties); |
| map->set_prototype(prototype); |
| ASSERT(map->has_fast_elements()); |
| |
| // If the function has only simple this property assignments add |
| // field descriptors for these to the initial map as the object |
| // cannot be constructed without having these properties. Guard by |
| // the inline_new flag so we only change the map if we generate a |
| // specialized construct stub. |
| ASSERT(in_object_properties <= Map::kMaxPreAllocatedPropertyFields); |
| if (fun->shared()->CanGenerateInlineConstructor(prototype)) { |
| int count = fun->shared()->this_property_assignments_count(); |
| if (count > in_object_properties) { |
| // Inline constructor can only handle inobject properties. |
| fun->shared()->ForbidInlineConstructor(); |
| } else { |
| Object* descriptors_obj; |
| { MaybeObject* maybe_descriptors_obj = DescriptorArray::Allocate(count); |
| if (!maybe_descriptors_obj->ToObject(&descriptors_obj)) { |
| return maybe_descriptors_obj; |
| } |
| } |
| DescriptorArray* descriptors = DescriptorArray::cast(descriptors_obj); |
| for (int i = 0; i < count; i++) { |
| String* name = fun->shared()->GetThisPropertyAssignmentName(i); |
| ASSERT(name->IsSymbol()); |
| FieldDescriptor field(name, i, NONE); |
| field.SetEnumerationIndex(i); |
| descriptors->Set(i, &field); |
| } |
| descriptors->SetNextEnumerationIndex(count); |
| descriptors->SortUnchecked(); |
| |
| // The descriptors may contain duplicates because the compiler does not |
| // guarantee the uniqueness of property names (it would have required |
| // quadratic time). Once the descriptors are sorted we can check for |
| // duplicates in linear time. |
| if (HasDuplicates(descriptors)) { |
| fun->shared()->ForbidInlineConstructor(); |
| } else { |
| map->set_instance_descriptors(descriptors); |
| map->set_pre_allocated_property_fields(count); |
| map->set_unused_property_fields(in_object_properties - count); |
| } |
| } |
| } |
| |
| fun->shared()->StartInobjectSlackTracking(map); |
| |
| return map; |
| } |
| |
| |
| 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 (eg, Smi::FromInt(0)) and the elements initialized to a |
| // fixed array (eg, Heap::empty_fixed_array()). Currently, the object |
| // verification code has to cope with (temporarily) invalid objects. See |
| // for example, JSArray::JSArrayVerify). |
| Object* filler; |
| // 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. |
| if (map->constructor()->IsJSFunction() && |
| JSFunction::cast(map->constructor())->shared()-> |
| IsInobjectSlackTrackingInProgress()) { |
| // We might want to shrink the object later. |
| ASSERT(obj->GetInternalFieldCount() == 0); |
| filler = Heap::one_pointer_filler_map(); |
| } else { |
| filler = Heap::undefined_value(); |
| } |
| obj->InitializeBody(map->instance_size(), filler); |
| } |
| |
| |
| MaybeObject* Heap::AllocateJSObjectFromMap(Map* map, PretenureFlag pretenure) { |
| // JSFunctions should be allocated using AllocateFunction to be |
| // properly initialized. |
| ASSERT(map->instance_type() != JS_FUNCTION_TYPE); |
| |
| // Both types of global objects should be allocated using |
| // AllocateGlobalObject to be properly initialized. |
| ASSERT(map->instance_type() != JS_GLOBAL_OBJECT_TYPE); |
| ASSERT(map->instance_type() != JS_BUILTINS_OBJECT_TYPE); |
| |
| // Allocate the backing storage for the properties. |
| int prop_size = |
| map->pre_allocated_property_fields() + |
| map->unused_property_fields() - |
| map->inobject_properties(); |
| ASSERT(prop_size >= 0); |
| Object* properties; |
| { MaybeObject* maybe_properties = AllocateFixedArray(prop_size, pretenure); |
| if (!maybe_properties->ToObject(&properties)) return maybe_properties; |
| } |
| |
| // Allocate the JSObject. |
| AllocationSpace space = |
| (pretenure == TENURED) ? OLD_POINTER_SPACE : NEW_SPACE; |
| if (map->instance_size() > MaxObjectSizeInPagedSpace()) space = LO_SPACE; |
| Object* obj; |
| { MaybeObject* maybe_obj = Allocate(map, space); |
| if (!maybe_obj->ToObject(&obj)) return maybe_obj; |
| } |
| |
| // Initialize the JSObject. |
| InitializeJSObjectFromMap(JSObject::cast(obj), |
| FixedArray::cast(properties), |
| map); |
| ASSERT(JSObject::cast(obj)->HasFastElements()); |
| return obj; |
| } |
| |
| |
| MaybeObject* Heap::AllocateJSObject(JSFunction* constructor, |
| PretenureFlag pretenure) { |
| // Allocate the initial map if absent. |
| if (!constructor->has_initial_map()) { |
| Object* initial_map; |
| { MaybeObject* maybe_initial_map = AllocateInitialMap(constructor); |
| if (!maybe_initial_map->ToObject(&initial_map)) return maybe_initial_map; |
| } |
| constructor->set_initial_map(Map::cast(initial_map)); |
| Map::cast(initial_map)->set_constructor(constructor); |
| } |
| // Allocate the object based on the constructors initial map. |
| MaybeObject* result = |
| AllocateJSObjectFromMap(constructor->initial_map(), pretenure); |
| #ifdef DEBUG |
| // Make sure result is NOT a global object if valid. |
| Object* non_failure; |
| ASSERT(!result->ToObject(&non_failure) || !non_failure->IsGlobalObject()); |
| #endif |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateGlobalObject(JSFunction* constructor) { |
| ASSERT(constructor->has_initial_map()); |
| Map* map = constructor->initial_map(); |
| |
| // Make sure no field properties are described in the initial map. |
| // This guarantees us that normalizing the properties does not |
| // require us to change property values to JSGlobalPropertyCells. |
| ASSERT(map->NextFreePropertyIndex() == 0); |
| |
| // Make sure we don't have a ton of pre-allocated slots in the |
| // global objects. They will be unused once we normalize the object. |
| ASSERT(map->unused_property_fields() == 0); |
| ASSERT(map->inobject_properties() == 0); |
| |
| // Initial size of the backing store to avoid resize of the storage during |
| // bootstrapping. The size differs between the JS global object ad the |
| // builtins object. |
| int initial_size = map->instance_type() == JS_GLOBAL_OBJECT_TYPE ? 64 : 512; |
| |
| // Allocate a dictionary object for backing storage. |
| Object* obj; |
| { MaybeObject* maybe_obj = |
| StringDictionary::Allocate( |
| map->NumberOfDescribedProperties() * 2 + initial_size); |
| if (!maybe_obj->ToObject(&obj)) return maybe_obj; |
| } |
| StringDictionary* dictionary = StringDictionary::cast(obj); |
| |
| // The global object might be created from an object template with accessors. |
| // Fill these accessors into the dictionary. |
| DescriptorArray* descs = map->instance_descriptors(); |
| for (int i = 0; i < descs->number_of_descriptors(); i++) { |
| PropertyDetails details = descs->GetDetails(i); |
| ASSERT(details.type() == CALLBACKS); // Only accessors are expected. |
| PropertyDetails d = |
| PropertyDetails(details.attributes(), CALLBACKS, details.index()); |
| Object* value = descs->GetCallbacksObject(i); |
| { MaybeObject* maybe_value = Heap::AllocateJSGlobalPropertyCell(value); |
| if (!maybe_value->ToObject(&value)) return maybe_value; |
| } |
| |
| Object* result; |
| { MaybeObject* maybe_result = dictionary->Add(descs->GetKey(i), value, d); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| dictionary = StringDictionary::cast(result); |
| } |
| |
| // Allocate the global object and initialize it with the backing store. |
| { MaybeObject* maybe_obj = Allocate(map, OLD_POINTER_SPACE); |
| if (!maybe_obj->ToObject(&obj)) return maybe_obj; |
| } |
| JSObject* global = JSObject::cast(obj); |
| InitializeJSObjectFromMap(global, dictionary, map); |
| |
| // Create a new map for the global object. |
| { MaybeObject* maybe_obj = map->CopyDropDescriptors(); |
| if (!maybe_obj->ToObject(&obj)) return maybe_obj; |
| } |
| Map* new_map = Map::cast(obj); |
| |
| // Setup the global object as a normalized object. |
| global->set_map(new_map); |
| global->map()->set_instance_descriptors(Heap::empty_descriptor_array()); |
| global->set_properties(dictionary); |
| |
| // Make sure result is a global object with properties in dictionary. |
| ASSERT(global->IsGlobalObject()); |
| ASSERT(!global->HasFastProperties()); |
| return global; |
| } |
| |
| |
| MaybeObject* Heap::CopyJSObject(JSObject* source) { |
| // Never used to copy functions. If functions need to be copied we |
| // have to be careful to clear the literals array. |
| ASSERT(!source->IsJSFunction()); |
| |
| // Make the clone. |
| Map* map = source->map(); |
| int object_size = map->instance_size(); |
| Object* clone; |
| |
| // If we're forced to always allocate, we use the general allocation |
| // functions which may leave us with an object in old space. |
| if (always_allocate()) { |
| { MaybeObject* maybe_clone = |
| AllocateRaw(object_size, NEW_SPACE, OLD_POINTER_SPACE); |
| if (!maybe_clone->ToObject(&clone)) return maybe_clone; |
| } |
| Address clone_address = HeapObject::cast(clone)->address(); |
| CopyBlock(clone_address, |
| source->address(), |
| object_size); |
| // Update write barrier for all fields that lie beyond the header. |
| RecordWrites(clone_address, |
| JSObject::kHeaderSize, |
| (object_size - JSObject::kHeaderSize) / kPointerSize); |
| } else { |
| { MaybeObject* maybe_clone = new_space_.AllocateRaw(object_size); |
| if (!maybe_clone->ToObject(&clone)) return maybe_clone; |
| } |
| ASSERT(Heap::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(HeapObject::cast(clone)->address(), |
| source->address(), |
| object_size); |
| } |
| |
| FixedArray* elements = FixedArray::cast(source->elements()); |
| FixedArray* properties = FixedArray::cast(source->properties()); |
| // Update elements if necessary. |
| if (elements->length() > 0) { |
| Object* elem; |
| { MaybeObject* maybe_elem = |
| (elements->map() == fixed_cow_array_map()) ? |
| elements : CopyFixedArray(elements); |
| if (!maybe_elem->ToObject(&elem)) return maybe_elem; |
| } |
| JSObject::cast(clone)->set_elements(FixedArray::cast(elem)); |
| } |
| // Update properties if necessary. |
| if (properties->length() > 0) { |
| Object* prop; |
| { MaybeObject* maybe_prop = CopyFixedArray(properties); |
| if (!maybe_prop->ToObject(&prop)) return maybe_prop; |
| } |
| JSObject::cast(clone)->set_properties(FixedArray::cast(prop)); |
| } |
| // Return the new clone. |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| ProducerHeapProfile::RecordJSObjectAllocation(clone); |
| #endif |
| return clone; |
| } |
| |
| |
| MaybeObject* Heap::ReinitializeJSGlobalProxy(JSFunction* constructor, |
| JSGlobalProxy* object) { |
| ASSERT(constructor->has_initial_map()); |
| Map* map = constructor->initial_map(); |
| |
| // Check that the already allocated object has the same size and type as |
| // objects allocated using the constructor. |
| ASSERT(map->instance_size() == object->map()->instance_size()); |
| ASSERT(map->instance_type() == object->map()->instance_type()); |
| |
| // Allocate the backing storage for the properties. |
| int prop_size = map->unused_property_fields() - map->inobject_properties(); |
| Object* properties; |
| { MaybeObject* maybe_properties = AllocateFixedArray(prop_size, TENURED); |
| if (!maybe_properties->ToObject(&properties)) return maybe_properties; |
| } |
| |
| // Reset the map for the object. |
| object->set_map(constructor->initial_map()); |
| |
| // Reinitialize the object from the constructor map. |
| InitializeJSObjectFromMap(object, FixedArray::cast(properties), map); |
| return object; |
| } |
| |
| |
| MaybeObject* Heap::AllocateStringFromAscii(Vector<const char> string, |
| PretenureFlag pretenure) { |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateRawAsciiString(string.length(), pretenure); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| // Copy the characters into the new object. |
| SeqAsciiString* string_result = SeqAsciiString::cast(result); |
| for (int i = 0; i < string.length(); i++) { |
| string_result->SeqAsciiStringSet(i, string[i]); |
| } |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateStringFromUtf8Slow(Vector<const char> string, |
| PretenureFlag pretenure) { |
| // V8 only supports characters in the Basic Multilingual Plane. |
| const uc32 kMaxSupportedChar = 0xFFFF; |
| // Count the number of characters in the UTF-8 string and check if |
| // it is an ASCII string. |
| Access<ScannerConstants::Utf8Decoder> |
| decoder(ScannerConstants::utf8_decoder()); |
| decoder->Reset(string.start(), string.length()); |
| int chars = 0; |
| while (decoder->has_more()) { |
| decoder->GetNext(); |
| chars++; |
| } |
| |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRawTwoByteString(chars, pretenure); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| // Convert and copy the characters into the new object. |
| String* string_result = String::cast(result); |
| decoder->Reset(string.start(), string.length()); |
| for (int i = 0; i < chars; i++) { |
| uc32 r = decoder->GetNext(); |
| if (r > kMaxSupportedChar) { r = unibrow::Utf8::kBadChar; } |
| string_result->Set(i, r); |
| } |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateStringFromTwoByte(Vector<const uc16> string, |
| PretenureFlag pretenure) { |
| // Check if the string is an ASCII string. |
| MaybeObject* maybe_result; |
| if (String::IsAscii(string.start(), string.length())) { |
| maybe_result = AllocateRawAsciiString(string.length(), pretenure); |
| } else { // It's not an ASCII string. |
| maybe_result = AllocateRawTwoByteString(string.length(), pretenure); |
| } |
| Object* result; |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| |
| // Copy the characters into the new object, which may be either ASCII or |
| // UTF-16. |
| String* string_result = String::cast(result); |
| for (int i = 0; i < string.length(); i++) { |
| string_result->Set(i, string[i]); |
| } |
| return result; |
| } |
| |
| |
| Map* Heap::SymbolMapForString(String* string) { |
| // If the string is in new space it cannot be used as a symbol. |
| if (InNewSpace(string)) return NULL; |
| |
| // Find the corresponding symbol map for strings. |
| Map* map = string->map(); |
| if (map == ascii_string_map()) return ascii_symbol_map(); |
| if (map == string_map()) return symbol_map(); |
| if (map == cons_string_map()) return cons_symbol_map(); |
| if (map == cons_ascii_string_map()) return cons_ascii_symbol_map(); |
| if (map == external_string_map()) return external_symbol_map(); |
| if (map == external_ascii_string_map()) return external_ascii_symbol_map(); |
| if (map == external_string_with_ascii_data_map()) { |
| return external_symbol_with_ascii_data_map(); |
| } |
| |
| // No match found. |
| return NULL; |
| } |
| |
| |
| MaybeObject* Heap::AllocateInternalSymbol(unibrow::CharacterStream* buffer, |
| int chars, |
| uint32_t hash_field) { |
| ASSERT(chars >= 0); |
| // Ensure the chars matches the number of characters in the buffer. |
| ASSERT(static_cast<unsigned>(chars) == buffer->Length()); |
| // Determine whether the string is ascii. |
| bool is_ascii = true; |
| while (buffer->has_more()) { |
| if (buffer->GetNext() > unibrow::Utf8::kMaxOneByteChar) { |
| is_ascii = false; |
| break; |
| } |
| } |
| buffer->Rewind(); |
| |
| // Compute map and object size. |
| int size; |
| Map* map; |
| |
| if (is_ascii) { |
| if (chars > SeqAsciiString::kMaxLength) { |
| return Failure::OutOfMemoryException(); |
| } |
| map = ascii_symbol_map(); |
| size = SeqAsciiString::SizeFor(chars); |
| } else { |
| if (chars > SeqTwoByteString::kMaxLength) { |
| return Failure::OutOfMemoryException(); |
| } |
| map = symbol_map(); |
| size = SeqTwoByteString::SizeFor(chars); |
| } |
| |
| // Allocate string. |
| Object* result; |
| { MaybeObject* maybe_result = (size > MaxObjectSizeInPagedSpace()) |
| ? lo_space_->AllocateRaw(size) |
| : old_data_space_->AllocateRaw(size); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| reinterpret_cast<HeapObject*>(result)->set_map(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); |
| |
| ASSERT_EQ(size, answer->Size()); |
| |
| // Fill in the characters. |
| for (int i = 0; i < chars; i++) { |
| answer->Set(i, buffer->GetNext()); |
| } |
| return answer; |
| } |
| |
| |
| MaybeObject* Heap::AllocateRawAsciiString(int length, PretenureFlag pretenure) { |
| if (length < 0 || length > SeqAsciiString::kMaxLength) { |
| return Failure::OutOfMemoryException(); |
| } |
| |
| int size = SeqAsciiString::SizeFor(length); |
| ASSERT(size <= SeqAsciiString::kMaxSize); |
| |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| AllocationSpace retry_space = OLD_DATA_SPACE; |
| |
| if (space == NEW_SPACE) { |
| if (size > kMaxObjectSizeInNewSpace) { |
| // Allocate in large object space, retry space will be ignored. |
| space = LO_SPACE; |
| } else if (size > MaxObjectSizeInPagedSpace()) { |
| // Allocate in new space, retry in large object space. |
| retry_space = LO_SPACE; |
| } |
| } else if (space == OLD_DATA_SPACE && size > MaxObjectSizeInPagedSpace()) { |
| space = LO_SPACE; |
| } |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRaw(size, space, retry_space); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| // Partially initialize the object. |
| HeapObject::cast(result)->set_map(ascii_string_map()); |
| String::cast(result)->set_length(length); |
| String::cast(result)->set_hash_field(String::kEmptyHashField); |
| ASSERT_EQ(size, HeapObject::cast(result)->Size()); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateRawTwoByteString(int length, |
| PretenureFlag pretenure) { |
| if (length < 0 || length > SeqTwoByteString::kMaxLength) { |
| return Failure::OutOfMemoryException(); |
| } |
| int size = SeqTwoByteString::SizeFor(length); |
| ASSERT(size <= SeqTwoByteString::kMaxSize); |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| AllocationSpace retry_space = OLD_DATA_SPACE; |
| |
| if (space == NEW_SPACE) { |
| if (size > kMaxObjectSizeInNewSpace) { |
| // Allocate in large object space, retry space will be ignored. |
| space = LO_SPACE; |
| } else if (size > MaxObjectSizeInPagedSpace()) { |
| // Allocate in new space, retry in large object space. |
| retry_space = LO_SPACE; |
| } |
| } else if (space == OLD_DATA_SPACE && size > MaxObjectSizeInPagedSpace()) { |
| space = LO_SPACE; |
| } |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRaw(size, space, retry_space); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| // Partially initialize the object. |
| HeapObject::cast(result)->set_map(string_map()); |
| String::cast(result)->set_length(length); |
| String::cast(result)->set_hash_field(String::kEmptyHashField); |
| ASSERT_EQ(size, HeapObject::cast(result)->Size()); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateEmptyFixedArray() { |
| int size = FixedArray::SizeFor(0); |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateRaw(size, OLD_DATA_SPACE, OLD_DATA_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| // Initialize the object. |
| reinterpret_cast<FixedArray*>(result)->set_map(fixed_array_map()); |
| reinterpret_cast<FixedArray*>(result)->set_length(0); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateRawFixedArray(int length) { |
| if (length < 0 || length > FixedArray::kMaxLength) { |
| return Failure::OutOfMemoryException(); |
| } |
| ASSERT(length > 0); |
| // Use the general function if we're forced to always allocate. |
| if (always_allocate()) return AllocateFixedArray(length, TENURED); |
| // Allocate the raw data for a fixed array. |
| int size = FixedArray::SizeFor(length); |
| return size <= kMaxObjectSizeInNewSpace |
| ? new_space_.AllocateRaw(size) |
| : lo_space_->AllocateRawFixedArray(size); |
| } |
| |
| |
| MaybeObject* Heap::CopyFixedArrayWithMap(FixedArray* src, Map* map) { |
| int len = src->length(); |
| Object* obj; |
| { MaybeObject* maybe_obj = AllocateRawFixedArray(len); |
| if (!maybe_obj->ToObject(&obj)) return maybe_obj; |
| } |
| if (Heap::InNewSpace(obj)) { |
| HeapObject* dst = HeapObject::cast(obj); |
| dst->set_map(map); |
| CopyBlock(dst->address() + kPointerSize, |
| src->address() + kPointerSize, |
| FixedArray::SizeFor(len) - kPointerSize); |
| return obj; |
| } |
| HeapObject::cast(obj)->set_map(map); |
| FixedArray* result = FixedArray::cast(obj); |
| result->set_length(len); |
| |
| // Copy the content |
| AssertNoAllocation no_gc; |
| WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc); |
| for (int i = 0; i < len; i++) result->set(i, src->get(i), mode); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateFixedArray(int length) { |
| ASSERT(length >= 0); |
| if (length == 0) return empty_fixed_array(); |
| Object* result; |
| { MaybeObject* maybe_result = AllocateRawFixedArray(length); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| // Initialize header. |
| FixedArray* array = reinterpret_cast<FixedArray*>(result); |
| array->set_map(fixed_array_map()); |
| array->set_length(length); |
| // Initialize body. |
| ASSERT(!Heap::InNewSpace(undefined_value())); |
| MemsetPointer(array->data_start(), undefined_value(), length); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateRawFixedArray(int length, PretenureFlag pretenure) { |
| if (length < 0 || length > FixedArray::kMaxLength) { |
| return Failure::OutOfMemoryException(); |
| } |
| |
| AllocationSpace space = |
| (pretenure == TENURED) ? OLD_POINTER_SPACE : NEW_SPACE; |
| int size = FixedArray::SizeFor(length); |
| if (space == NEW_SPACE && size > kMaxObjectSizeInNewSpace) { |
| // Too big for new space. |
| space = LO_SPACE; |
| } else if (space == OLD_POINTER_SPACE && |
| size > MaxObjectSizeInPagedSpace()) { |
| // Too big for old pointer space. |
| space = LO_SPACE; |
| } |
| |
| AllocationSpace retry_space = |
| (size <= MaxObjectSizeInPagedSpace()) ? OLD_POINTER_SPACE : LO_SPACE; |
| |
| return AllocateRaw(size, space, retry_space); |
| } |
| |
| |
| MUST_USE_RESULT static MaybeObject* AllocateFixedArrayWithFiller( |
| int length, |
| PretenureFlag pretenure, |
| Object* filler) { |
| ASSERT(length >= 0); |
| ASSERT(Heap::empty_fixed_array()->IsFixedArray()); |
| if (length == 0) return Heap::empty_fixed_array(); |
| |
| ASSERT(!Heap::InNewSpace(filler)); |
| Object* result; |
| { MaybeObject* maybe_result = Heap::AllocateRawFixedArray(length, pretenure); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| HeapObject::cast(result)->set_map(Heap::fixed_array_map()); |
| FixedArray* array = FixedArray::cast(result); |
| array->set_length(length); |
| MemsetPointer(array->data_start(), filler, length); |
| return array; |
| } |
| |
| |
| MaybeObject* Heap::AllocateFixedArray(int length, PretenureFlag pretenure) { |
| return AllocateFixedArrayWithFiller(length, pretenure, undefined_value()); |
| } |
| |
| |
| MaybeObject* Heap::AllocateFixedArrayWithHoles(int length, |
| PretenureFlag pretenure) { |
| return AllocateFixedArrayWithFiller(length, pretenure, the_hole_value()); |
| } |
| |
| |
| MaybeObject* Heap::AllocateUninitializedFixedArray(int length) { |
| if (length == 0) return empty_fixed_array(); |
| |
| Object* obj; |
| { MaybeObject* maybe_obj = AllocateRawFixedArray(length); |
| if (!maybe_obj->ToObject(&obj)) return maybe_obj; |
| } |
| |
| reinterpret_cast<FixedArray*>(obj)->set_map(fixed_array_map()); |
| FixedArray::cast(obj)->set_length(length); |
| return obj; |
| } |
| |
| |
| MaybeObject* Heap::AllocateHashTable(int length, PretenureFlag pretenure) { |
| Object* result; |
| { MaybeObject* maybe_result = Heap::AllocateFixedArray(length, pretenure); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| reinterpret_cast<HeapObject*>(result)->set_map(hash_table_map()); |
| ASSERT(result->IsHashTable()); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateGlobalContext() { |
| Object* result; |
| { MaybeObject* maybe_result = |
| Heap::AllocateFixedArray(Context::GLOBAL_CONTEXT_SLOTS); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map(global_context_map()); |
| ASSERT(context->IsGlobalContext()); |
| ASSERT(result->IsContext()); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateFunctionContext(int length, JSFunction* function) { |
| ASSERT(length >= Context::MIN_CONTEXT_SLOTS); |
| Object* result; |
| { MaybeObject* maybe_result = Heap::AllocateFixedArray(length); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map(context_map()); |
| context->set_closure(function); |
| context->set_fcontext(context); |
| context->set_previous(NULL); |
| context->set_extension(NULL); |
| context->set_global(function->context()->global()); |
| ASSERT(!context->IsGlobalContext()); |
| ASSERT(context->is_function_context()); |
| ASSERT(result->IsContext()); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateWithContext(Context* previous, |
| JSObject* extension, |
| bool is_catch_context) { |
| Object* result; |
| { MaybeObject* maybe_result = |
| Heap::AllocateFixedArray(Context::MIN_CONTEXT_SLOTS); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map(is_catch_context ? catch_context_map() : context_map()); |
| context->set_closure(previous->closure()); |
| context->set_fcontext(previous->fcontext()); |
| context->set_previous(previous); |
| context->set_extension(extension); |
| context->set_global(previous->global()); |
| ASSERT(!context->IsGlobalContext()); |
| ASSERT(!context->is_function_context()); |
| ASSERT(result->IsContext()); |
| return result; |
| } |
| |
| |
| MaybeObject* 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 Failure::InternalError(); |
| } |
| int size = map->instance_size(); |
| AllocationSpace space = |
| (size > MaxObjectSizeInPagedSpace()) ? LO_SPACE : OLD_POINTER_SPACE; |
| Object* result; |
| { MaybeObject* maybe_result = Heap::Allocate(map, space); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Struct::cast(result)->InitializeBody(size); |
| return result; |
| } |
| |
| |
| bool Heap::IdleNotification() { |
| static const int kIdlesBeforeScavenge = 4; |
| static const int kIdlesBeforeMarkSweep = 7; |
| static const int kIdlesBeforeMarkCompact = 8; |
| static const int kMaxIdleCount = kIdlesBeforeMarkCompact + 1; |
| static const unsigned int kGCsBetweenCleanup = 4; |
| static int number_idle_notifications = 0; |
| static unsigned int last_gc_count = gc_count_; |
| |
| bool uncommit = true; |
| bool finished = false; |
| |
| // Reset the number of idle notifications received when a number of |
| // GCs have taken place. This allows another round of cleanup based |
| // on idle notifications if enough work has been carried out to |
| // provoke a number of garbage collections. |
| if (gc_count_ - last_gc_count < kGCsBetweenCleanup) { |
| number_idle_notifications = |
| Min(number_idle_notifications + 1, kMaxIdleCount); |
| } else { |
| number_idle_notifications = 0; |
| last_gc_count = gc_count_; |
| } |
| |
| if (number_idle_notifications == kIdlesBeforeScavenge) { |
| if (contexts_disposed_ > 0) { |
| HistogramTimerScope scope(&Counters::gc_context); |
| CollectAllGarbage(false); |
| } else { |
| CollectGarbage(NEW_SPACE); |
| } |
| new_space_.Shrink(); |
| last_gc_count = gc_count_; |
| } else if (number_idle_notifications == kIdlesBeforeMarkSweep) { |
| // Before doing the mark-sweep collections we clear the |
| // compilation cache to avoid hanging on to source code and |
| // generated code for cached functions. |
| CompilationCache::Clear(); |
| |
| CollectAllGarbage(false); |
| new_space_.Shrink(); |
| last_gc_count = gc_count_; |
| |
| } else if (number_idle_notifications == kIdlesBeforeMarkCompact) { |
| CollectAllGarbage(true); |
| new_space_.Shrink(); |
| last_gc_count = gc_count_; |
| finished = true; |
| |
| } else if (contexts_disposed_ > 0) { |
| if (FLAG_expose_gc) { |
| contexts_disposed_ = 0; |
| } else { |
| HistogramTimerScope scope(&Counters::gc_context); |
| CollectAllGarbage(false); |
| last_gc_count = gc_count_; |
| } |
| // If this is the first idle notification, we reset the |
| // notification count to avoid letting idle notifications for |
| // context disposal garbage collections start a potentially too |
| // aggressive idle GC cycle. |
| if (number_idle_notifications <= 1) { |
| number_idle_notifications = 0; |
| uncommit = false; |
| } |
| } else if (number_idle_notifications > kIdlesBeforeMarkCompact) { |
| // If we have received more than kIdlesBeforeMarkCompact idle |
| // notifications we do not perform any cleanup because we don't |
| // expect to gain much by doing so. |
| finished = true; |
| } |
| |
| // Make sure that we have no pending context disposals and |
| // conditionally uncommit from space. |
| ASSERT(contexts_disposed_ == 0); |
| if (uncommit) Heap::UncommitFromSpace(); |
| return finished; |
| } |
| |
| |
| #ifdef DEBUG |
| |
| void Heap::Print() { |
| if (!HasBeenSetup()) return; |
| Top::PrintStack(); |
| AllSpaces spaces; |
| 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(); |
| // 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(); |
| } |
| |
| |
| // 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("mark-compact GC : %d\n", mc_count_); |
| PrintF("old_gen_promotion_limit_ %" V8_PTR_PREFIX "d\n", |
| old_gen_promotion_limit_); |
| PrintF("old_gen_allocation_limit_ %" V8_PTR_PREFIX "d\n", |
| old_gen_allocation_limit_); |
| |
| PrintF("\n"); |
| PrintF("Number of handles : %d\n", HandleScope::NumberOfHandles()); |
| GlobalHandles::PrintStats(); |
| PrintF("\n"); |
| |
| PrintF("Heap statistics : "); |
| MemoryAllocator::ReportStatistics(); |
| PrintF("To space : "); |
| new_space_.ReportStatistics(); |
| PrintF("Old pointer space : "); |
| old_pointer_space_->ReportStatistics(); |
| PrintF("Old data space : "); |
| old_data_space_->ReportStatistics(); |
| PrintF("Code space : "); |
| code_space_->ReportStatistics(); |
| PrintF("Map space : "); |
| map_space_->ReportStatistics(); |
| PrintF("Cell space : "); |
| cell_space_->ReportStatistics(); |
| PrintF("Large object space : "); |
| lo_space_->ReportStatistics(); |
| PrintF(">>>>>> ========================================= >>>>>>\n"); |
| } |
| |
| #endif // DEBUG |
| |
| bool Heap::Contains(HeapObject* value) { |
| return Contains(value->address()); |
| } |
| |
| |
| bool Heap::Contains(Address addr) { |
| if (OS::IsOutsideAllocatedSpace(addr)) return false; |
| return HasBeenSetup() && |
| (new_space_.ToSpaceContains(addr) || |
| old_pointer_space_->Contains(addr) || |
| old_data_space_->Contains(addr) || |
| code_space_->Contains(addr) || |
| map_space_->Contains(addr) || |
| cell_space_->Contains(addr) || |
| lo_space_->SlowContains(addr)); |
| } |
| |
| |
| bool Heap::InSpace(HeapObject* value, AllocationSpace space) { |
| return InSpace(value->address(), space); |
| } |
| |
| |
| bool Heap::InSpace(Address addr, AllocationSpace space) { |
| if (OS::IsOutsideAllocatedSpace(addr)) return false; |
| if (!HasBeenSetup()) return false; |
| |
| switch (space) { |
| case NEW_SPACE: |
| return new_space_.ToSpaceContains(addr); |
| case OLD_POINTER_SPACE: |
| return old_pointer_space_->Contains(addr); |
| case OLD_DATA_SPACE: |
| return old_data_space_->Contains(addr); |
| case CODE_SPACE: |
| return code_space_->Contains(addr); |
| case MAP_SPACE: |
| return map_space_->Contains(addr); |
| case CELL_SPACE: |
| return cell_space_->Contains(addr); |
| case LO_SPACE: |
| return lo_space_->SlowContains(addr); |
| } |
| |
| return false; |
| } |
| |
| |
| #ifdef DEBUG |
| static void DummyScavengePointer(HeapObject** p) { |
| } |
| |
| |
| static void VerifyPointersUnderWatermark( |
| PagedSpace* space, |
| DirtyRegionCallback visit_dirty_region) { |
| PageIterator it(space, PageIterator::PAGES_IN_USE); |
| |
| while (it.has_next()) { |
| Page* page = it.next(); |
| Address start = page->ObjectAreaStart(); |
| Address end = page->AllocationWatermark(); |
| |
| Heap::IterateDirtyRegions(Page::kAllRegionsDirtyMarks, |
| start, |
| end, |
| visit_dirty_region, |
| &DummyScavengePointer); |
| } |
| } |
| |
| |
| static void VerifyPointersUnderWatermark(LargeObjectSpace* space) { |
| LargeObjectIterator it(space); |
| for (HeapObject* object = it.next(); object != NULL; object = it.next()) { |
| if (object->IsFixedArray()) { |
| Address slot_address = object->address(); |
| Address end = object->address() + object->Size(); |
| |
| while (slot_address < end) { |
| HeapObject** slot = reinterpret_cast<HeapObject**>(slot_address); |
| // When we are not in GC the Heap::InNewSpace() predicate |
| // checks that pointers which satisfy predicate point into |
| // the active semispace. |
| Heap::InNewSpace(*slot); |
| slot_address += kPointerSize; |
| } |
| } |
| } |
| } |
| |
| |
| void Heap::Verify() { |
| ASSERT(HasBeenSetup()); |
| |
| VerifyPointersVisitor visitor; |
| IterateRoots(&visitor, VISIT_ONLY_STRONG); |
| |
| new_space_.Verify(); |
| |
| VerifyPointersAndDirtyRegionsVisitor dirty_regions_visitor; |
| old_pointer_space_->Verify(&dirty_regions_visitor); |
| map_space_->Verify(&dirty_regions_visitor); |
| |
| VerifyPointersUnderWatermark(old_pointer_space_, |
| &IteratePointersInDirtyRegion); |
| VerifyPointersUnderWatermark(map_space_, |
| &IteratePointersInDirtyMapsRegion); |
| VerifyPointersUnderWatermark(lo_space_); |
| |
| VerifyPageWatermarkValidity(old_pointer_space_, ALL_INVALID); |
| VerifyPageWatermarkValidity(map_space_, ALL_INVALID); |
| |
| VerifyPointersVisitor no_dirty_regions_visitor; |
| old_data_space_->Verify(&no_dirty_regions_visitor); |
| code_space_->Verify(&no_dirty_regions_visitor); |
| cell_space_->Verify(&no_dirty_regions_visitor); |
| |
| lo_space_->Verify(); |
| } |
| #endif // DEBUG |
| |
| |
| MaybeObject* Heap::LookupSymbol(Vector<const char> string) { |
| Object* symbol = NULL; |
| Object* new_table; |
| { MaybeObject* maybe_new_table = |
| symbol_table()->LookupSymbol(string, &symbol); |
| if (!maybe_new_table->ToObject(&new_table)) return maybe_new_table; |
| } |
| // Can't use set_symbol_table because SymbolTable::cast knows that |
| // SymbolTable is a singleton and checks for identity. |
| roots_[kSymbolTableRootIndex] = new_table; |
| ASSERT(symbol != NULL); |
| return symbol; |
| } |
| |
| |
| MaybeObject* Heap::LookupAsciiSymbol(Vector<const char> string) { |
| Object* symbol = NULL; |
| Object* new_table; |
| { MaybeObject* maybe_new_table = |
| symbol_table()->LookupAsciiSymbol(string, &symbol); |
| if (!maybe_new_table->ToObject(&new_table)) return maybe_new_table; |
| } |
| // Can't use set_symbol_table because SymbolTable::cast knows that |
| // SymbolTable is a singleton and checks for identity. |
| roots_[kSymbolTableRootIndex] = new_table; |
| ASSERT(symbol != NULL); |
| return symbol; |
| } |
| |
| |
| MaybeObject* Heap::LookupTwoByteSymbol(Vector<const uc16> string) { |
| Object* symbol = NULL; |
| Object* new_table; |
| { MaybeObject* maybe_new_table = |
| symbol_table()->LookupTwoByteSymbol(string, &symbol); |
| if (!maybe_new_table->ToObject(&new_table)) return maybe_new_table; |
| } |
| // Can't use set_symbol_table because SymbolTable::cast knows that |
| // SymbolTable is a singleton and checks for identity. |
| roots_[kSymbolTableRootIndex] = new_table; |
| ASSERT(symbol != NULL); |
| return symbol; |
| } |
| |
| |
| MaybeObject* Heap::LookupSymbol(String* string) { |
| if (string->IsSymbol()) return string; |
| Object* symbol = NULL; |
| Object* new_table; |
| { MaybeObject* maybe_new_table = |
| symbol_table()->LookupString(string, &symbol); |
| if (!maybe_new_table->ToObject(&new_table)) return maybe_new_table; |
| } |
| // Can't use set_symbol_table because SymbolTable::cast knows that |
| // SymbolTable is a singleton and checks for identity. |
| roots_[kSymbolTableRootIndex] = new_table; |
| ASSERT(symbol != NULL); |
| return symbol; |
| } |
| |
| |
| bool Heap::LookupSymbolIfExists(String* string, String** symbol) { |
| if (string->IsSymbol()) { |
| *symbol = string; |
| return true; |
| } |
| return symbol_table()->LookupSymbolIfExists(string, symbol); |
| } |
| |
| |
| #ifdef DEBUG |
| void Heap::ZapFromSpace() { |
| ASSERT(reinterpret_cast<Object*>(kFromSpaceZapValue)->IsFailure()); |
| for (Address a = new_space_.FromSpaceLow(); |
| a < new_space_.FromSpaceHigh(); |
| a += kPointerSize) { |
| Memory::Address_at(a) = kFromSpaceZapValue; |
| } |
| } |
| #endif // DEBUG |
| |
| |
| bool Heap::IteratePointersInDirtyRegion(Address start, |
| Address end, |
| ObjectSlotCallback copy_object_func) { |
| Address slot_address = start; |
| bool pointers_to_new_space_found = false; |
| |
| while (slot_address < end) { |
| Object** slot = reinterpret_cast<Object**>(slot_address); |
| if (Heap::InNewSpace(*slot)) { |
| ASSERT((*slot)->IsHeapObject()); |
| copy_object_func(reinterpret_cast<HeapObject**>(slot)); |
| if (Heap::InNewSpace(*slot)) { |
| ASSERT((*slot)->IsHeapObject()); |
| pointers_to_new_space_found = true; |
| } |
| } |
| slot_address += kPointerSize; |
| } |
| return pointers_to_new_space_found; |
| } |
| |
| |
| // Compute start address of the first map following given addr. |
| static inline Address MapStartAlign(Address addr) { |
| Address page = Page::FromAddress(addr)->ObjectAreaStart(); |
| return page + (((addr - page) + (Map::kSize - 1)) / Map::kSize * Map::kSize); |
| } |
| |
| |
| // Compute end address of the first map preceding given addr. |
| static inline Address MapEndAlign(Address addr) { |
| Address page = Page::FromAllocationTop(addr)->ObjectAreaStart(); |
| return page + ((addr - page) / Map::kSize * Map::kSize); |
| } |
| |
| |
| static bool IteratePointersInDirtyMaps(Address start, |
| Address end, |
| ObjectSlotCallback copy_object_func) { |
| ASSERT(MapStartAlign(start) == start); |
| ASSERT(MapEndAlign(end) == end); |
| |
| Address map_address = start; |
| bool pointers_to_new_space_found = false; |
| |
| while (map_address < end) { |
| ASSERT(!Heap::InNewSpace(Memory::Object_at(map_address))); |
| ASSERT(Memory::Object_at(map_address)->IsMap()); |
| |
| Address pointer_fields_start = map_address + Map::kPointerFieldsBeginOffset; |
| Address pointer_fields_end = map_address + Map::kPointerFieldsEndOffset; |
| |
| if (Heap::IteratePointersInDirtyRegion(pointer_fields_start, |
| pointer_fields_end, |
| copy_object_func)) { |
| pointers_to_new_space_found = true; |
| } |
| |
| map_address += Map::kSize; |
| } |
| |
| return pointers_to_new_space_found; |
| } |
| |
| |
| bool Heap::IteratePointersInDirtyMapsRegion( |
| Address start, |
| Address end, |
| ObjectSlotCallback copy_object_func) { |
| Address map_aligned_start = MapStartAlign(start); |
| Address map_aligned_end = MapEndAlign(end); |
| |
| bool contains_pointers_to_new_space = false; |
| |
| if (map_aligned_start != start) { |
| Address prev_map = map_aligned_start - Map::kSize; |
| ASSERT(Memory::Object_at(prev_map)->IsMap()); |
| |
| Address pointer_fields_start = |
| Max(start, prev_map + Map::kPointerFieldsBeginOffset); |
| |
| Address pointer_fields_end = |
| Min(prev_map + Map::kPointerFieldsEndOffset, end); |
| |
| contains_pointers_to_new_space = |
| IteratePointersInDirtyRegion(pointer_fields_start, |
| pointer_fields_end, |
| copy_object_func) |
| || contains_pointers_to_new_space; |
| } |
| |
| contains_pointers_to_new_space = |
| IteratePointersInDirtyMaps(map_aligned_start, |
| map_aligned_end, |
| copy_object_func) |
| || contains_pointers_to_new_space; |
| |
| if (map_aligned_end != end) { |
| ASSERT(Memory::Object_at(map_aligned_end)->IsMap()); |
| |
| Address pointer_fields_start = |
| map_aligned_end + Map::kPointerFieldsBeginOffset; |
| |
| Address pointer_fields_end = |
| Min(end, map_aligned_end + Map::kPointerFieldsEndOffset); |
| |
| contains_pointers_to_new_space = |
| IteratePointersInDirtyRegion(pointer_fields_start, |
| pointer_fields_end, |
| copy_object_func) |
| || contains_pointers_to_new_space; |
| } |
| |
| return contains_pointers_to_new_space; |
| } |
| |
| |
| void Heap::IterateAndMarkPointersToFromSpace(Address start, |
| Address end, |
| ObjectSlotCallback callback) { |
| Address slot_address = start; |
| Page* page = Page::FromAddress(start); |
| |
| uint32_t marks = page->GetRegionMarks(); |
| |
| while (slot_address < end) { |
| Object** slot = reinterpret_cast<Object**>(slot_address); |
| if (Heap::InFromSpace(*slot)) { |
| ASSERT((*slot)->IsHeapObject()); |
| callback(reinterpret_cast<HeapObject**>(slot)); |
| if (Heap::InNewSpace(*slot)) { |
| ASSERT((*slot)->IsHeapObject()); |
| marks |= page->GetRegionMaskForAddress(slot_address); |
| } |
| } |
| slot_address += kPointerSize; |
| } |
| |
| page->SetRegionMarks(marks); |
| } |
| |
| |
| uint32_t Heap::IterateDirtyRegions( |
| uint32_t marks, |
| Address area_start, |
| Address area_end, |
| DirtyRegionCallback visit_dirty_region, |
| ObjectSlotCallback copy_object_func) { |
| uint32_t newmarks = 0; |
| uint32_t mask = 1; |
| |
| if (area_start >= area_end) { |
| return newmarks; |
| } |
| |
| Address region_start = area_start; |
| |
| // area_start does not necessarily coincide with start of the first region. |
| // Thus to calculate the beginning of the next region we have to align |
| // area_start by Page::kRegionSize. |
| Address second_region = |
| reinterpret_cast<Address>( |
| reinterpret_cast<intptr_t>(area_start + Page::kRegionSize) & |
| ~Page::kRegionAlignmentMask); |
| |
| // Next region might be beyond area_end. |
| Address region_end = Min(second_region, area_end); |
| |
| if (marks & mask) { |
| if (visit_dirty_region(region_start, region_end, copy_object_func)) { |
| newmarks |= mask; |
| } |
| } |
| mask <<= 1; |
| |
| // Iterate subsequent regions which fully lay inside [area_start, area_end[. |
| region_start = region_end; |
| region_end = region_start + Page::kRegionSize; |
| |
| while (region_end <= area_end) { |
| if (marks & mask) { |
| if (visit_dirty_region(region_start, region_end, copy_object_func)) { |
| newmarks |= mask; |
| } |
| } |
| |
| region_start = region_end; |
| region_end = region_start + Page::kRegionSize; |
| |
| mask <<= 1; |
| } |
| |
| if (region_start != area_end) { |
| // A small piece of area left uniterated because area_end does not coincide |
| // with region end. Check whether region covering last part of area is |
| // dirty. |
| if (marks & mask) { |
| if (visit_dirty_region(region_start, area_end, copy_object_func)) { |
| newmarks |= mask; |
| } |
| } |
| } |
| |
| return newmarks; |
| } |
| |
| |
| |
| void Heap::IterateDirtyRegions( |
| PagedSpace* space, |
| DirtyRegionCallback visit_dirty_region, |
| ObjectSlotCallback copy_object_func, |
| ExpectedPageWatermarkState expected_page_watermark_state) { |
| |
| PageIterator it(space, PageIterator::PAGES_IN_USE); |
| |
| while (it.has_next()) { |
| Page* page = it.next(); |
| uint32_t marks = page->GetRegionMarks(); |
| |
| if (marks != Page::kAllRegionsCleanMarks) { |
| Address start = page->ObjectAreaStart(); |
| |
| // Do not try to visit pointers beyond page allocation watermark. |
| // Page can contain garbage pointers there. |
| Address end; |
| |
| if ((expected_page_watermark_state == WATERMARK_SHOULD_BE_VALID) || |
| page->IsWatermarkValid()) { |
| end = page->AllocationWatermark(); |
| } else { |
| end = page->CachedAllocationWatermark(); |
| } |
| |
| ASSERT(space == old_pointer_space_ || |
| (space == map_space_ && |
| ((page->ObjectAreaStart() - end) % Map::kSize == 0))); |
| |
| page->SetRegionMarks(IterateDirtyRegions(marks, |
| start, |
| end, |
| visit_dirty_region, |
| copy_object_func)); |
| } |
| |
| // Mark page watermark as invalid to maintain watermark validity invariant. |
| // See Page::FlipMeaningOfInvalidatedWatermarkFlag() for details. |
| page->InvalidateWatermark(true); |
| } |
| } |
| |
| |
| 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_[kSymbolTableRootIndex])); |
| v->Synchronize("symbol_table"); |
| if (mode != VISIT_ALL_IN_SCAVENGE) { |
| // Scavenge collections have special processing for this. |
| ExternalStringTable::Iterate(v); |
| } |
| v->Synchronize("external_string_table"); |
| } |
| |
| |
| void Heap::IterateStrongRoots(ObjectVisitor* v, VisitMode mode) { |
| v->VisitPointers(&roots_[0], &roots_[kStrongRootListLength]); |
| v->Synchronize("strong_root_list"); |
| |
| v->VisitPointer(BitCast<Object**>(&hidden_symbol_)); |
| v->Synchronize("symbol"); |
| |
| Bootstrapper::Iterate(v); |
| v->Synchronize("bootstrapper"); |
| Top::Iterate(v); |
| v->Synchronize("top"); |
| Relocatable::Iterate(v); |
| v->Synchronize("relocatable"); |
| |
| #ifdef ENABLE_DEBUGGER_SUPPORT |
| Debug::Iterate(v); |
| #endif |
| v->Synchronize("debug"); |
| CompilationCache::Iterate(v); |
| v->Synchronize("compilationcache"); |
| |
| // Iterate over local handles in handle scopes. |
| HandleScopeImplementer::Iterate(v); |
| v->Synchronize("handlescope"); |
| |
| // 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) { |
| Builtins::IterateBuiltins(v); |
| } |
| v->Synchronize("builtins"); |
| |
| // Iterate over global handles. |
| if (mode == VISIT_ONLY_STRONG) { |
| GlobalHandles::IterateStrongRoots(v); |
| } else { |
| GlobalHandles::IterateAllRoots(v); |
| } |
| v->Synchronize("globalhandles"); |
| |
| // Iterate over pointers being held by inactive threads. |
| ThreadManager::Iterate(v); |
| v->Synchronize("threadmanager"); |
| |
| // Iterate over the pointers the Serialization/Deserialization code is |
| // holding. |
| // During garbage collection this keeps the partial snapshot cache alive. |
| // During deserialization of the startup snapshot this creates the partial |
| // snapshot cache and deserializes the objects it refers to. During |
| // serialization this does nothing, since the partial snapshot cache is |
| // empty. However the next thing we do is create the partial snapshot, |
| // filling up the partial snapshot cache with objects it needs as we go. |
| SerializerDeserializer::Iterate(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. |
| } |
| |
| |
| // Flag is set when the heap has been configured. The heap can be repeatedly |
| // configured through the API until it is setup. |
| static bool heap_configured = false; |
| |
| // 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_semispace_size, |
| int max_old_gen_size, |
| int max_executable_size) { |
| if (HasBeenSetup()) return false; |
| |
| if (max_semispace_size > 0) max_semispace_size_ = max_semispace_size; |
| |
| if (Snapshot::IsEnabled()) { |
| // If we are using a snapshot we always reserve the default amount |
| // of memory for each semispace because code in the snapshot has |
| // write-barrier code that relies on the size and alignment of new |
| // space. We therefore cannot use a larger max semispace size |
| // than the default reserved semispace size. |
| if (max_semispace_size_ > reserved_semispace_size_) { |
| max_semispace_size_ = reserved_semispace_size_; |
| } |
| } else { |
| // If we are not using snapshots we reserve space for the actual |
| // max semispace size. |
| reserved_semispace_size_ = max_semispace_size_; |
| } |
| |
| if (max_old_gen_size > 0) max_old_generation_size_ = max_old_gen_size; |
| if (max_executable_size > 0) { |
| max_executable_size_ = RoundUp(max_executable_size, Page::kPageSize); |
| } |
| |
| // 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_; |
| } |
| |
| // The new space size must be a power of two to support single-bit testing |
| // for containment. |
| max_semispace_size_ = RoundUpToPowerOf2(max_semispace_size_); |
| reserved_semispace_size_ = RoundUpToPowerOf2(reserved_semispace_size_); |
| initial_semispace_size_ = Min(initial_semispace_size_, max_semispace_size_); |
| external_allocation_limit_ = 10 * max_semispace_size_; |
| |
| // The old generation is paged. |
| max_old_generation_size_ = RoundUp(max_old_generation_size_, Page::kPageSize); |
| |
| heap_configured = true; |
| return true; |
| } |
| |
| |
| bool Heap::ConfigureHeapDefault() { |
| return ConfigureHeap(FLAG_max_new_space_size / 2 * KB, |
| FLAG_max_old_space_size * MB, |
| FLAG_max_executable_size * MB); |
| } |
| |
| |
| 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_pointer_space_size = old_pointer_space_->Size(); |
| *stats->old_pointer_space_capacity = old_pointer_space_->Capacity(); |
| *stats->old_data_space_size = old_data_space_->Size(); |
| *stats->old_data_space_capacity = old_data_space_->Capacity(); |
| *stats->code_space_size = code_space_->Size(); |
| *stats->code_space_capacity = code_space_->Capacity(); |
| *stats->map_space_size = map_space_->Size(); |
| *stats->map_space_capacity = map_space_->Capacity(); |
| *stats->cell_space_size = cell_space_->Size(); |
| *stats->cell_space_capacity = cell_space_->Capacity(); |
| *stats->lo_space_size = lo_space_->Size(); |
| GlobalHandles::RecordStats(stats); |
| *stats->memory_allocator_size = MemoryAllocator::Size(); |
| *stats->memory_allocator_capacity = |
| MemoryAllocator::Size() + MemoryAllocator::Available(); |
| *stats->os_error = OS::GetLastError(); |
| if (take_snapshot) { |
| HeapIterator iterator(HeapIterator::kFilterFreeListNodes); |
| for (HeapObject* obj = iterator.next(); |
| obj != NULL; |
| obj = iterator.next()) { |
| InstanceType type = obj->map()->instance_type(); |
| ASSERT(0 <= type && type <= LAST_TYPE); |
| stats->objects_per_type[type]++; |
| stats->size_per_type[type] += obj->Size(); |
| } |
| } |
| } |
| |
| |
| intptr_t Heap::PromotedSpaceSize() { |
| return old_pointer_space_->Size() |
| + old_data_space_->Size() |
| + code_space_->Size() |
| + map_space_->Size() |
| + cell_space_->Size() |
| + lo_space_->Size(); |
| } |
| |
| |
| int 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_; |
| } |
| |
| |
| bool Heap::Setup(bool create_heap_objects) { |
| // 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 (eg, 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 (!heap_configured) { |
| if (!ConfigureHeapDefault()) return false; |
| } |
| |
| ScavengingVisitor::Initialize(); |
| NewSpaceScavenger::Initialize(); |
| MarkCompactCollector::Initialize(); |
| |
| MarkMapPointersAsEncoded(false); |
| |
| // Setup memory allocator and reserve a chunk of memory for new |
| // space. The chunk is double the size of the requested reserved |
| // new space size to ensure that we can find a pair of semispaces that |
| // are contiguous and aligned to their size. |
| if (!MemoryAllocator::Setup(MaxReserved(), MaxExecutableSize())) return false; |
| void* chunk = |
| MemoryAllocator::ReserveInitialChunk(4 * reserved_semispace_size_); |
| if (chunk == NULL) return false; |
| |
| // Align the pair of semispaces to their size, which must be a power |
| // of 2. |
| Address new_space_start = |
| RoundUp(reinterpret_cast<byte*>(chunk), 2 * reserved_semispace_size_); |
| if (!new_space_.Setup(new_space_start, 2 * reserved_semispace_size_)) { |
| return false; |
| } |
| |
| // Initialize old pointer space. |
| old_pointer_space_ = |
| new OldSpace(max_old_generation_size_, OLD_POINTER_SPACE, NOT_EXECUTABLE); |
| if (old_pointer_space_ == NULL) return false; |
| if (!old_pointer_space_->Setup(NULL, 0)) return false; |
| |
| // Initialize old data space. |
| old_data_space_ = |
| new OldSpace(max_old_generation_size_, OLD_DATA_SPACE, NOT_EXECUTABLE); |
| if (old_data_space_ == NULL) return false; |
| if (!old_data_space_->Setup(NULL, 0)) return false; |
| |
| // Initialize the code space, set its maximum capacity to the old |
| // generation size. It needs executable memory. |
| // On 64-bit platform(s), we put all code objects in a 2 GB range of |
| // virtual address space, so that they can call each other with near calls. |
| if (code_range_size_ > 0) { |
| if (!CodeRange::Setup(code_range_size_)) { |
| return false; |
| } |
| } |
| |
| code_space_ = |
| new OldSpace(max_old_generation_size_, CODE_SPACE, EXECUTABLE); |
| if (code_space_ == NULL) return false; |
| if (!code_space_->Setup(NULL, 0)) return false; |
| |
| // Initialize map space. |
| map_space_ = new MapSpace(FLAG_use_big_map_space |
| ? max_old_generation_size_ |
| : MapSpace::kMaxMapPageIndex * Page::kPageSize, |
| FLAG_max_map_space_pages, |
| MAP_SPACE); |
| if (map_space_ == NULL) return false; |
| if (!map_space_->Setup(NULL, 0)) return false; |
| |
| // Initialize global property cell space. |
| cell_space_ = new CellSpace(max_old_generation_size_, CELL_SPACE); |
| if (cell_space_ == NULL) return false; |
| if (!cell_space_->Setup(NULL, 0)) 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(LO_SPACE); |
| if (lo_space_ == NULL) return false; |
| if (!lo_space_->Setup()) return false; |
| |
| if (create_heap_objects) { |
| // Create initial maps. |
| if (!CreateInitialMaps()) return false; |
| if (!CreateApiObjects()) return false; |
| |
| // Create initial objects |
| if (!CreateInitialObjects()) return false; |
| |
| global_contexts_list_ = undefined_value(); |
| } |
| |
| LOG(IntPtrTEvent("heap-capacity", Capacity())); |
| LOG(IntPtrTEvent("heap-available", Available())); |
| |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| // This should be called only after initial objects have been created. |
| ProducerHeapProfile::Setup(); |
| #endif |
| |
| return true; |
| } |
| |
| |
| void Heap::SetStackLimits() { |
| // 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*>( |
| (StackGuard::jslimit() & ~kSmiTagMask) | kSmiTag); |
| roots_[kRealStackLimitRootIndex] = |
| reinterpret_cast<Object*>( |
| (StackGuard::real_jslimit() & ~kSmiTagMask) | kSmiTag); |
| } |
| |
| |
| void Heap::TearDown() { |
| if (FLAG_print_cumulative_gc_stat) { |
| PrintF("\n\n"); |
| PrintF("gc_count=%d ", gc_count_); |
| PrintF("mark_sweep_count=%d ", ms_count_); |
| PrintF("mark_compact_count=%d ", mc_count_); |
| PrintF("max_gc_pause=%d ", GCTracer::get_max_gc_pause()); |
| PrintF("min_in_mutator=%d ", GCTracer::get_min_in_mutator()); |
| PrintF("max_alive_after_gc=%" V8_PTR_PREFIX "d ", |
| GCTracer::get_max_alive_after_gc()); |
| PrintF("\n\n"); |
| } |
| |
| GlobalHandles::TearDown(); |
| |
| ExternalStringTable::TearDown(); |
| |
| new_space_.TearDown(); |
| |
| if (old_pointer_space_ != NULL) { |
| old_pointer_space_->TearDown(); |
| delete old_pointer_space_; |
| old_pointer_space_ = NULL; |
| } |
| |
| if (old_data_space_ != NULL) { |
| old_data_space_->TearDown(); |
| delete old_data_space_; |
| old_data_space_ = NULL; |
| } |
| |
| if (code_space_ != NULL) { |
| code_space_->TearDown(); |
| delete code_space_; |
| code_space_ = NULL; |
| } |
| |
| if (map_space_ != NULL) { |
| map_space_->TearDown(); |
| delete map_space_; |
| map_space_ = NULL; |
| } |
| |
| if (cell_space_ != NULL) { |
| cell_space_->TearDown(); |
| delete cell_space_; |
| cell_space_ = NULL; |
| } |
| |
| if (lo_space_ != NULL) { |
| lo_space_->TearDown(); |
| delete lo_space_; |
| lo_space_ = NULL; |
| } |
| |
| MemoryAllocator::TearDown(); |
| } |
| |
| |
| void Heap::Shrink() { |
| // Try to shrink all paged spaces. |
| PagedSpaces spaces; |
| for (PagedSpace* space = spaces.next(); space != NULL; space = spaces.next()) |
| space->Shrink(); |
| } |
| |
| |
| #ifdef ENABLE_HEAP_PROTECTION |
| |
| void Heap::Protect() { |
| if (HasBeenSetup()) { |
| AllSpaces spaces; |
| for (Space* space = spaces.next(); space != NULL; space = spaces.next()) |
| space->Protect(); |
| } |
| } |
| |
| |
| void Heap::Unprotect() { |
| if (HasBeenSetup()) { |
| AllSpaces spaces; |
| for (Space* space = spaces.next(); space != NULL; space = spaces.next()) |
| space->Unprotect(); |
| } |
| } |
| |
| #endif |
| |
| |
| void Heap::AddGCPrologueCallback(GCPrologueCallback callback, GCType gc_type) { |
| ASSERT(callback != NULL); |
| GCPrologueCallbackPair pair(callback, gc_type); |
| ASSERT(!gc_prologue_callbacks_.Contains(pair)); |
| return gc_prologue_callbacks_.Add(pair); |
| } |
| |
| |
| void Heap::RemoveGCPrologueCallback(GCPrologueCallback callback) { |
| ASSERT(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(GCEpilogueCallback callback, GCType gc_type) { |
| ASSERT(callback != NULL); |
| GCEpilogueCallbackPair pair(callback, gc_type); |
| ASSERT(!gc_epilogue_callbacks_.Contains(pair)); |
| return gc_epilogue_callbacks_.Add(pair); |
| } |
| |
| |
| void Heap::RemoveGCEpilogueCallback(GCEpilogueCallback callback) { |
| ASSERT(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(); |
| } |
| |
| |
| #ifdef DEBUG |
| |
| class PrintHandleVisitor: public ObjectVisitor { |
| public: |
| void VisitPointers(Object** start, Object** end) { |
| 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; |
| HandleScopeImplementer::Iterate(&v); |
| } |
| |
| #endif |
| |
| |
| Space* AllSpaces::next() { |
| switch (counter_++) { |
| case NEW_SPACE: |
| return Heap::new_space(); |
| case OLD_POINTER_SPACE: |
| return Heap::old_pointer_space(); |
| case OLD_DATA_SPACE: |
| return Heap::old_data_space(); |
| case CODE_SPACE: |
| return Heap::code_space(); |
| case MAP_SPACE: |
| return Heap::map_space(); |
| case CELL_SPACE: |
| return Heap::cell_space(); |
| case LO_SPACE: |
| return Heap::lo_space(); |
| default: |
| return NULL; |
| } |
| } |
| |
| |
| PagedSpace* PagedSpaces::next() { |
| switch (counter_++) { |
| case OLD_POINTER_SPACE: |
| return Heap::old_pointer_space(); |
| case OLD_DATA_SPACE: |
| return Heap::old_data_space(); |
| case CODE_SPACE: |
| return Heap::code_space(); |
| case MAP_SPACE: |
| return Heap::map_space(); |
| case CELL_SPACE: |
| return Heap::cell_space(); |
| default: |
| return NULL; |
| } |
| } |
| |
| |
| |
| OldSpace* OldSpaces::next() { |
| switch (counter_++) { |
| case OLD_POINTER_SPACE: |
| return Heap::old_pointer_space(); |
| case OLD_DATA_SPACE: |
| return Heap::old_data_space(); |
| case CODE_SPACE: |
| return Heap::code_space(); |
| default: |
| return NULL; |
| } |
| } |
| |
| |
| SpaceIterator::SpaceIterator() |
| : current_space_(FIRST_SPACE), |
| iterator_(NULL), |
| size_func_(NULL) { |
| } |
| |
| |
| SpaceIterator::SpaceIterator(HeapObjectCallback size_func) |
| : current_space_(FIRST_SPACE), |
| iterator_(NULL), |
| size_func_(size_func) { |
| } |
| |
| |
| 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() { |
| ASSERT(iterator_ == NULL); |
| |
| switch (current_space_) { |
| case NEW_SPACE: |
| iterator_ = new SemiSpaceIterator(Heap::new_space(), size_func_); |
| break; |
| case OLD_POINTER_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::old_pointer_space(), size_func_); |
| break; |
| case OLD_DATA_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::old_data_space(), size_func_); |
| break; |
| case CODE_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::code_space(), size_func_); |
| break; |
| case MAP_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::map_space(), size_func_); |
| break; |
| case CELL_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::cell_space(), size_func_); |
| break; |
| case LO_SPACE: |
| iterator_ = new LargeObjectIterator(Heap::lo_space(), size_func_); |
| break; |
| } |
| |
| // Return the newly allocated iterator; |
| ASSERT(iterator_ != NULL); |
| return iterator_; |
| } |
| |
| |
| class HeapObjectsFilter { |
| public: |
| virtual ~HeapObjectsFilter() {} |
| virtual bool SkipObject(HeapObject* object) = 0; |
| }; |
| |
| |
| class FreeListNodesFilter : public HeapObjectsFilter { |
| public: |
| FreeListNodesFilter() { |
| MarkFreeListNodes(); |
| } |
| |
| bool SkipObject(HeapObject* object) { |
| if (object->IsMarked()) { |
| object->ClearMark(); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| private: |
| void MarkFreeListNodes() { |
| Heap::old_pointer_space()->MarkFreeListNodes(); |
| Heap::old_data_space()->MarkFreeListNodes(); |
| MarkCodeSpaceFreeListNodes(); |
| Heap::map_space()->MarkFreeListNodes(); |
| Heap::cell_space()->MarkFreeListNodes(); |
| } |
| |
| void MarkCodeSpaceFreeListNodes() { |
| // For code space, using FreeListNode::IsFreeListNode is OK. |
| HeapObjectIterator iter(Heap::code_space()); |
| for (HeapObject* obj = iter.next_object(); |
| obj != NULL; |
| obj = iter.next_object()) { |
| if (FreeListNode::IsFreeListNode(obj)) obj->SetMark(); |
| } |
| } |
| |
| AssertNoAllocation no_alloc; |
| }; |
| |
| |
| class UnreachableObjectsFilter : public HeapObjectsFilter { |
| public: |
| UnreachableObjectsFilter() { |
| MarkUnreachableObjects(); |
| } |
| |
| bool SkipObject(HeapObject* object) { |
| if (object->IsMarked()) { |
| object->ClearMark(); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| private: |
| class UnmarkingVisitor : public ObjectVisitor { |
| public: |
| UnmarkingVisitor() : list_(10) {} |
| |
| void VisitPointers(Object** start, Object** end) { |
| for (Object** p = start; p < end; p++) { |
| if (!(*p)->IsHeapObject()) continue; |
| HeapObject* obj = HeapObject::cast(*p); |
| if (obj->IsMarked()) { |
| obj->ClearMark(); |
| list_.Add(obj); |
| } |
| } |
| } |
| |
| bool can_process() { return !list_.is_empty(); } |
| |
| void ProcessNext() { |
| HeapObject* obj = list_.RemoveLast(); |
| obj->Iterate(this); |
| } |
| |
| private: |
| List<HeapObject*> list_; |
| }; |
| |
| void MarkUnreachableObjects() { |
| HeapIterator iterator; |
| for (HeapObject* obj = iterator.next(); |
| obj != NULL; |
| obj = iterator.next()) { |
| obj->SetMark(); |
| } |
| UnmarkingVisitor visitor; |
| Heap::IterateRoots(&visitor, VISIT_ALL); |
| while (visitor.can_process()) |
| visitor.ProcessNext(); |
| } |
| |
| AssertNoAllocation no_alloc; |
| }; |
| |
| |
| HeapIterator::HeapIterator() |
| : filtering_(HeapIterator::kNoFiltering), |
| filter_(NULL) { |
| Init(); |
| } |
| |
| |
| HeapIterator::HeapIterator(HeapIterator::HeapObjectsFiltering filtering) |
| : filtering_(filtering), |
| filter_(NULL) { |
| Init(); |
| } |
| |
| |
| HeapIterator::~HeapIterator() { |
| Shutdown(); |
| } |
| |
| |
| void HeapIterator::Init() { |
| // Start the iteration. |
| space_iterator_ = filtering_ == kNoFiltering ? new SpaceIterator : |
| new SpaceIterator(MarkCompactCollector::SizeOfMarkedObject); |
| switch (filtering_) { |
| case kFilterFreeListNodes: |
| filter_ = new FreeListNodesFilter; |
| break; |
| case kFilterUnreachable: |
| filter_ = new UnreachableObjectsFilter; |
| break; |
| default: |
| break; |
| } |
| object_iterator_ = space_iterator_->next(); |
| } |
| |
| |
| void HeapIterator::Shutdown() { |
| #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) { |
| ASSERT(object_iterator_ == NULL); |
| } |
| #endif |
| // Make sure the last iterator is deallocated. |
| delete space_iterator_; |
| space_iterator_ = NULL; |
| object_iterator_ = NULL; |
| delete filter_; |
| filter_ = NULL; |
| } |
| |
| |
| HeapObject* HeapIterator::next() { |
| if (filter_ == NULL) return NextObject(); |
| |
| HeapObject* obj = NextObject(); |
| while (obj != NULL && filter_->SkipObject(obj)) obj = NextObject(); |
| return obj; |
| } |
| |
| |
| HeapObject* HeapIterator::NextObject() { |
| // No iterator means we are done. |
| if (object_iterator_ == NULL) return NULL; |
| |
| 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_ = NULL; |
| return NULL; |
| } |
| |
| |
| void HeapIterator::reset() { |
| // Restart the iterator. |
| Shutdown(); |
| Init(); |
| } |
| |
| |
| #if defined(DEBUG) || defined(LIVE_OBJECT_LIST) |
| |
| Object* const PathTracer::kAnyGlobalObject = reinterpret_cast<Object*>(NULL); |
| |
| class PathTracer::MarkVisitor: public ObjectVisitor { |
| public: |
| explicit MarkVisitor(PathTracer* tracer) : tracer_(tracer) {} |
| void VisitPointers(Object** start, Object** end) { |
| // 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) { |
| // 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) { |
| ASSERT((search_target_ == kAnyGlobalObject) || |
| search_target_->IsHeapObject()); |
| found_target_in_trace_ = false; |
| object_stack_.Clear(); |
| |
| MarkVisitor mark_visitor(this); |
| MarkRecursively(root, &mark_visitor); |
| |
| UnmarkVisitor unmark_visitor(this); |
| UnmarkRecursively(root, &unmark_visitor); |
| |
| ProcessResults(); |
| } |
| |
| |
| void PathTracer::MarkRecursively(Object** p, MarkVisitor* mark_visitor) { |
| if (!(*p)->IsHeapObject()) return; |
| |
| HeapObject* obj = HeapObject::cast(*p); |
| |
| Object* map = obj->map(); |
| |
| if (!map->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_global_context = obj->IsGlobalContext(); |
| |
| // not visited yet |
| Map* map_p = reinterpret_cast<Map*>(HeapObject::cast(map)); |
| |
| Address map_addr = map_p->address(); |
| |
| obj->set_map(reinterpret_cast<Map*>(map_addr + kMarkTag)); |
| |
| // Scan the object body. |
| if (is_global_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_p->instance_type(), |
| obj->SizeFromMap(map_p), |
| mark_visitor); |
| } |
| |
| // Scan the map after the body because the body is a lot more interesting |
| // when doing leak detection. |
| MarkRecursively(&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); |
| |
| Object* map = obj->map(); |
| |
| if (map->IsHeapObject()) return; // unmarked already |
| |
| Address map_addr = reinterpret_cast<Address>(map); |
| |
| map_addr -= kMarkTag; |
| |
| ASSERT_TAG_ALIGNED(map_addr); |
| |
| HeapObject* map_p = HeapObject::FromAddress(map_addr); |
| |
| obj->set_map(reinterpret_cast<Map*>(map_p)); |
| |
| UnmarkRecursively(reinterpret_cast<Object**>(&map_p), unmark_visitor); |
| |
| obj->IterateBody(Map::cast(map_p)->instance_type(), |
| obj->SizeFromMap(Map::cast(map_p)), |
| unmark_visitor); |
| } |
| |
| |
| void PathTracer::ProcessResults() { |
| if (found_target_) { |
| PrintF("=====================================\n"); |
| PrintF("==== Path to object ====\n"); |
| PrintF("=====================================\n\n"); |
| |
| ASSERT(!object_stack_.is_empty()); |
| for (int i = 0; i < object_stack_.length(); i++) { |
| if (i > 0) PrintF("\n |\n |\n V\n\n"); |
| Object* obj = object_stack_[i]; |
| obj->Print(); |
| } |
| PrintF("=====================================\n"); |
| } |
| } |
| #endif // DEBUG || LIVE_OBJECT_LIST |
| |
| |
| #ifdef DEBUG |
| // 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 |
| |
| |
| static intptr_t CountTotalHolesSize() { |
| intptr_t holes_size = 0; |
| OldSpaces spaces; |
| for (OldSpace* space = spaces.next(); |
| space != NULL; |
| space = spaces.next()) { |
| holes_size += space->Waste() + space->AvailableFree(); |
| } |
| return holes_size; |
| } |
| |
| |
| GCTracer::GCTracer() |
| : start_time_(0.0), |
| start_size_(0), |
| gc_count_(0), |
| full_gc_count_(0), |
| is_compacting_(false), |
| marked_count_(0), |
| allocated_since_last_gc_(0), |
| spent_in_mutator_(0), |
| promoted_objects_size_(0) { |
| // These two fields reflect the state of the previous full collection. |
| // Set them before they are changed by the collector. |
| previous_has_compacted_ = MarkCompactCollector::HasCompacted(); |
| previous_marked_count_ = MarkCompactCollector::previous_marked_count(); |
| if (!FLAG_trace_gc && !FLAG_print_cumulative_gc_stat) return; |
| start_time_ = OS::TimeCurrentMillis(); |
| start_size_ = Heap::SizeOfObjects(); |
| |
| for (int i = 0; i < Scope::kNumberOfScopes; i++) { |
| scopes_[i] = 0; |
| } |
| |
| in_free_list_or_wasted_before_gc_ = CountTotalHolesSize(); |
| |
| allocated_since_last_gc_ = Heap::SizeOfObjects() - alive_after_last_gc_; |
| |
| if (last_gc_end_timestamp_ > 0) { |
| spent_in_mutator_ = Max(start_time_ - last_gc_end_timestamp_, 0.0); |
| } |
| } |
| |
| |
| GCTracer::~GCTracer() { |
| // Printf ONE line iff flag is set. |
| if (!FLAG_trace_gc && !FLAG_print_cumulative_gc_stat) return; |
| |
| bool first_gc = (last_gc_end_timestamp_ == 0); |
| |
| alive_after_last_gc_ = Heap::SizeOfObjects(); |
| last_gc_end_timestamp_ = OS::TimeCurrentMillis(); |
| |
| int time = static_cast<int>(last_gc_end_timestamp_ - start_time_); |
| |
| // Update cumulative GC statistics if required. |
| if (FLAG_print_cumulative_gc_stat) { |
| max_gc_pause_ = Max(max_gc_pause_, time); |
| max_alive_after_gc_ = Max(max_alive_after_gc_, alive_after_last_gc_); |
| if (!first_gc) { |
| min_in_mutator_ = Min(min_in_mutator_, |
| static_cast<int>(spent_in_mutator_)); |
| } |
| } |
| |
| if (!FLAG_trace_gc_nvp) { |
| int external_time = static_cast<int>(scopes_[Scope::EXTERNAL]); |
| |
| PrintF("%s %.1f -> %.1f MB, ", |
| CollectorString(), |
| static_cast<double>(start_size_) / MB, |
| SizeOfHeapObjects()); |
| |
| if (external_time > 0) PrintF("%d / ", external_time); |
| PrintF("%d ms.\n", time); |
| } else { |
| PrintF("pause=%d ", time); |
| PrintF("mutator=%d ", |
| static_cast<int>(spent_in_mutator_)); |
| |
| PrintF("gc="); |
| switch (collector_) { |
| case SCAVENGER: |
| PrintF("s"); |
| break; |
| case MARK_COMPACTOR: |
| PrintF(MarkCompactCollector::HasCompacted() ? "mc" : "ms"); |
| break; |
| default: |
| UNREACHABLE(); |
| } |
| PrintF(" "); |
| |
| PrintF("external=%d ", static_cast<int>(scopes_[Scope::EXTERNAL])); |
| PrintF("mark=%d ", static_cast<int>(scopes_[Scope::MC_MARK])); |
| PrintF("sweep=%d ", static_cast<int>(scopes_[Scope::MC_SWEEP])); |
| PrintF("sweepns=%d ", static_cast<int>(scopes_[Scope::MC_SWEEP_NEWSPACE])); |
| PrintF("compact=%d ", static_cast<int>(scopes_[Scope::MC_COMPACT])); |
| |
| PrintF("total_size_before=%" V8_PTR_PREFIX "d ", start_size_); |
| PrintF("total_size_after=%" V8_PTR_PREFIX "d ", Heap::SizeOfObjects()); |
| PrintF("holes_size_before=%" V8_PTR_PREFIX "d ", |
| in_free_list_or_wasted_before_gc_); |
| PrintF("holes_size_after=%" V8_PTR_PREFIX "d ", CountTotalHolesSize()); |
| |
| PrintF("allocated=%" V8_PTR_PREFIX "d ", allocated_since_last_gc_); |
| PrintF("promoted=%" V8_PTR_PREFIX "d ", promoted_objects_size_); |
| |
| PrintF("\n"); |
| } |
| |
| #if defined(ENABLE_LOGGING_AND_PROFILING) |
| Heap::PrintShortHeapStatistics(); |
| #endif |
| } |
| |
| |
| const char* GCTracer::CollectorString() { |
| switch (collector_) { |
| case SCAVENGER: |
| return "Scavenge"; |
| case MARK_COMPACTOR: |
| return MarkCompactCollector::HasCompacted() ? "Mark-compact" |
| : "Mark-sweep"; |
| } |
| return "Unknown GC"; |
| } |
| |
| |
| int KeyedLookupCache::Hash(Map* map, String* name) { |
| // 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(Map* map, String* name) { |
| int index = Hash(map, name); |
| Key& key = keys_[index]; |
| if ((key.map == map) && key.name->Equals(name)) { |
| return field_offsets_[index]; |
| } |
| return -1; |
| } |
| |
| |
| void KeyedLookupCache::Update(Map* map, String* name, int field_offset) { |
| String* symbol; |
| if (Heap::LookupSymbolIfExists(name, &symbol)) { |
| int index = Hash(map, symbol); |
| Key& key = keys_[index]; |
| key.map = map; |
| key.name = symbol; |
| field_offsets_[index] = field_offset; |
| } |
| } |
| |
| |
| void KeyedLookupCache::Clear() { |
| for (int index = 0; index < kLength; index++) keys_[index].map = NULL; |
| } |
| |
| |
| KeyedLookupCache::Key KeyedLookupCache::keys_[KeyedLookupCache::kLength]; |
| |
| |
| int KeyedLookupCache::field_offsets_[KeyedLookupCache::kLength]; |
| |
| |
| void DescriptorLookupCache::Clear() { |
| for (int index = 0; index < kLength; index++) keys_[index].array = NULL; |
| } |
| |
| |
| DescriptorLookupCache::Key |
| DescriptorLookupCache::keys_[DescriptorLookupCache::kLength]; |
| |
| int DescriptorLookupCache::results_[DescriptorLookupCache::kLength]; |
| |
| |
| #ifdef DEBUG |
| void Heap::GarbageCollectionGreedyCheck() { |
| ASSERT(FLAG_gc_greedy); |
| if (Bootstrapper::IsActive()) return; |
| if (disallow_allocation_failure()) return; |
| CollectGarbage(NEW_SPACE); |
| } |
| #endif |
| |
| |
| TranscendentalCache::TranscendentalCache(TranscendentalCache::Type t) |
| : type_(t) { |
| uint32_t in0 = 0xffffffffu; // Bit-pattern for a NaN that isn't |
| uint32_t in1 = 0xffffffffu; // generated by the FPU. |
| for (int i = 0; i < kCacheSize; i++) { |
| elements_[i].in[0] = in0; |
| elements_[i].in[1] = in1; |
| elements_[i].output = NULL; |
| } |
| } |
| |
| |
| TranscendentalCache* TranscendentalCache::caches_[kNumberOfCaches]; |
| |
| |
| void TranscendentalCache::Clear() { |
| for (int i = 0; i < kNumberOfCaches; i++) { |
| if (caches_[i] != NULL) { |
| delete caches_[i]; |
| caches_[i] = NULL; |
| } |
| } |
| } |
| |
| |
| void ExternalStringTable::CleanUp() { |
| int last = 0; |
| for (int i = 0; i < new_space_strings_.length(); ++i) { |
| if (new_space_strings_[i] == Heap::raw_unchecked_null_value()) continue; |
| 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); |
| last = 0; |
| for (int i = 0; i < old_space_strings_.length(); ++i) { |
| if (old_space_strings_[i] == Heap::raw_unchecked_null_value()) continue; |
| ASSERT(!Heap::InNewSpace(old_space_strings_[i])); |
| old_space_strings_[last++] = old_space_strings_[i]; |
| } |
| old_space_strings_.Rewind(last); |
| Verify(); |
| } |
| |
| |
| void ExternalStringTable::TearDown() { |
| new_space_strings_.Free(); |
| old_space_strings_.Free(); |
| } |
| |
| |
| List<Object*> ExternalStringTable::new_space_strings_; |
| List<Object*> ExternalStringTable::old_space_strings_; |
| |
| } } // namespace v8::internal |