| // Copyright 2012 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.h" |
| #include "compilation-cache.h" |
| #include "debug.h" |
| #include "deoptimizer.h" |
| #include "global-handles.h" |
| #include "heap-profiler.h" |
| #include "incremental-marking.h" |
| #include "liveobjectlist-inl.h" |
| #include "mark-compact.h" |
| #include "natives.h" |
| #include "objects-visiting.h" |
| #include "objects-visiting-inl.h" |
| #include "once.h" |
| #include "runtime-profiler.h" |
| #include "scopeinfo.h" |
| #include "snapshot.h" |
| #include "store-buffer.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 |
| #if V8_TARGET_ARCH_MIPS && !V8_INTERPRETED_REGEXP |
| #include "regexp-macro-assembler.h" |
| #include "mips/regexp-macro-assembler-mips.h" |
| #endif |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| Heap::Heap() |
| : isolate_(NULL), |
| // semispace_size_ should be a power of 2 and old_generation_size_ should be |
| // a multiple of Page::kPageSize. |
| #if defined(V8_TARGET_ARCH_X64) |
| #define LUMP_OF_MEMORY (2 * MB) |
| code_range_size_(512*MB), |
| #else |
| #define LUMP_OF_MEMORY MB |
| code_range_size_(0), |
| #endif |
| #if defined(ANDROID) |
| reserved_semispace_size_(4 * Max(LUMP_OF_MEMORY, Page::kPageSize)), |
| max_semispace_size_(4 * Max(LUMP_OF_MEMORY, Page::kPageSize)), |
| initial_semispace_size_(Page::kPageSize), |
| max_old_generation_size_(192*MB), |
| max_executable_size_(max_old_generation_size_), |
| #else |
| reserved_semispace_size_(8 * Max(LUMP_OF_MEMORY, Page::kPageSize)), |
| max_semispace_size_(8 * Max(LUMP_OF_MEMORY, Page::kPageSize)), |
| initial_semispace_size_(Page::kPageSize), |
| max_old_generation_size_(700ul * LUMP_OF_MEMORY), |
| max_executable_size_(256l * LUMP_OF_MEMORY), |
| #endif |
| |
| // Variables set based on semispace_size_ and old_generation_size_ in |
| // ConfigureHeap (survived_since_last_expansion_, external_allocation_limit_) |
| // Will be 4 * reserved_semispace_size_ to ensure that young |
| // generation can be aligned to its size. |
| survived_since_last_expansion_(0), |
| sweep_generation_(0), |
| always_allocate_scope_depth_(0), |
| linear_allocation_scope_depth_(0), |
| contexts_disposed_(0), |
| global_ic_age_(0), |
| scan_on_scavenge_pages_(0), |
| new_space_(this), |
| old_pointer_space_(NULL), |
| old_data_space_(NULL), |
| code_space_(NULL), |
| map_space_(NULL), |
| cell_space_(NULL), |
| lo_space_(NULL), |
| gc_state_(NOT_IN_GC), |
| gc_post_processing_depth_(0), |
| ms_count_(0), |
| gc_count_(0), |
| remembered_unmapped_pages_index_(0), |
| unflattened_strings_length_(0), |
| #ifdef DEBUG |
| allocation_allowed_(true), |
| allocation_timeout_(0), |
| disallow_allocation_failure_(false), |
| debug_utils_(NULL), |
| #endif // DEBUG |
| new_space_high_promotion_mode_active_(false), |
| old_gen_promotion_limit_(kMinimumPromotionLimit), |
| old_gen_allocation_limit_(kMinimumAllocationLimit), |
| old_gen_limit_factor_(1), |
| size_of_old_gen_at_last_old_space_gc_(0), |
| external_allocation_limit_(0), |
| amount_of_external_allocated_memory_(0), |
| amount_of_external_allocated_memory_at_last_global_gc_(0), |
| old_gen_exhausted_(false), |
| store_buffer_rebuilder_(store_buffer()), |
| hidden_symbol_(NULL), |
| global_gc_prologue_callback_(NULL), |
| global_gc_epilogue_callback_(NULL), |
| gc_safe_size_of_old_object_(NULL), |
| total_regexp_code_generated_(0), |
| tracer_(NULL), |
| young_survivors_after_last_gc_(0), |
| high_survival_rate_period_length_(0), |
| survival_rate_(0), |
| previous_survival_rate_trend_(Heap::STABLE), |
| survival_rate_trend_(Heap::STABLE), |
| max_gc_pause_(0), |
| max_alive_after_gc_(0), |
| min_in_mutator_(kMaxInt), |
| alive_after_last_gc_(0), |
| last_gc_end_timestamp_(0.0), |
| store_buffer_(this), |
| marking_(this), |
| incremental_marking_(this), |
| number_idle_notifications_(0), |
| last_idle_notification_gc_count_(0), |
| last_idle_notification_gc_count_init_(false), |
| mark_sweeps_since_idle_round_started_(0), |
| ms_count_at_last_idle_notification_(0), |
| gc_count_at_last_idle_gc_(0), |
| scavenges_since_last_idle_round_(kIdleScavengeThreshold), |
| promotion_queue_(this), |
| configured_(false), |
| chunks_queued_for_free_(NULL), |
| relocation_mutex_(NULL) { |
| // Allow build-time customization of the max semispace size. Building |
| // V8 with snapshots and a non-default max semispace size is much |
| // easier if you can define it as part of the build environment. |
| #if defined(V8_MAX_SEMISPACE_SIZE) |
| max_semispace_size_ = reserved_semispace_size_ = V8_MAX_SEMISPACE_SIZE; |
| #endif |
| |
| intptr_t max_virtual = OS::MaxVirtualMemory(); |
| |
| if (max_virtual > 0) { |
| if (code_range_size_ > 0) { |
| // Reserve no more than 1/8 of the memory for the code range. |
| code_range_size_ = Min(code_range_size_, max_virtual >> 3); |
| } |
| } |
| |
| memset(roots_, 0, sizeof(roots_[0]) * kRootListLength); |
| global_contexts_list_ = NULL; |
| mark_compact_collector_.heap_ = this; |
| external_string_table_.heap_ = this; |
| // Put a dummy entry in the remembered pages so we can find the list the |
| // minidump even if there are no real unmapped pages. |
| RememberUnmappedPage(NULL, false); |
| |
| ClearObjectStats(true); |
| } |
| |
| |
| 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 isolate()->memory_allocator()->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) { |
| if (IntrusiveMarking::IsMarked(object)) { |
| return IntrusiveMarking::SizeOfMarkedObject(object); |
| } |
| return object->SizeFromMap(object->map()); |
| } |
| |
| |
| GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space, |
| const char** reason) { |
| // Is global GC requested? |
| if (space != NEW_SPACE) { |
| isolate_->counters()->gc_compactor_caused_by_request()->Increment(); |
| *reason = "GC in old space requested"; |
| return MARK_COMPACTOR; |
| } |
| |
| if (FLAG_gc_global || (FLAG_stress_compaction && (gc_count_ & 1) != 0)) { |
| *reason = "GC in old space forced by flags"; |
| return MARK_COMPACTOR; |
| } |
| |
| // Is enough data promoted to justify a global GC? |
| if (OldGenerationPromotionLimitReached()) { |
| isolate_->counters()->gc_compactor_caused_by_promoted_data()->Increment(); |
| *reason = "promotion limit reached"; |
| return MARK_COMPACTOR; |
| } |
| |
| // Have allocation in OLD and LO failed? |
| if (old_gen_exhausted_) { |
| isolate_->counters()-> |
| gc_compactor_caused_by_oldspace_exhaustion()->Increment(); |
| *reason = "old generations exhausted"; |
| return MARK_COMPACTOR; |
| } |
| |
| // Is there enough space left in OLD to guarantee that a scavenge can |
| // succeed? |
| // |
| // Note that MemoryAllocator->MaxAvailable() undercounts the memory available |
| // for object promotion. It counts only the bytes that the memory |
| // allocator has not yet allocated from the OS and assigned to any space, |
| // and does not count available bytes already in the old space or code |
| // space. Undercounting is safe---we may get an unrequested full GC when |
| // a scavenge would have succeeded. |
| if (isolate_->memory_allocator()->MaxAvailable() <= new_space_.Size()) { |
| isolate_->counters()-> |
| gc_compactor_caused_by_oldspace_exhaustion()->Increment(); |
| *reason = "scavenge might not succeed"; |
| return MARK_COMPACTOR; |
| } |
| |
| // Default |
| *reason = NULL; |
| return SCAVENGER; |
| } |
| |
| |
| // TODO(1238405): Combine the infrastructure for --heap-stats and |
| // --log-gc to avoid the complicated preprocessor and flag testing. |
| void Heap::ReportStatisticsBeforeGC() { |
| // Heap::ReportHeapStatistics will also log NewSpace statistics when |
| // compiled --log-gc is set. The following logic is used to avoid |
| // double logging. |
| #ifdef DEBUG |
| if (FLAG_heap_stats || FLAG_log_gc) new_space_.CollectStatistics(); |
| if (FLAG_heap_stats) { |
| ReportHeapStatistics("Before GC"); |
| } else if (FLAG_log_gc) { |
| new_space_.ReportStatistics(); |
| } |
| if (FLAG_heap_stats || FLAG_log_gc) new_space_.ClearHistograms(); |
| #else |
| if (FLAG_log_gc) { |
| new_space_.CollectStatistics(); |
| new_space_.ReportStatistics(); |
| new_space_.ClearHistograms(); |
| } |
| #endif // DEBUG |
| } |
| |
| |
| void Heap::PrintShortHeapStatistics() { |
| if (!FLAG_trace_gc_verbose) return; |
| PrintPID("Memory allocator, used: %6" V8_PTR_PREFIX "d KB" |
| ", available: %6" V8_PTR_PREFIX "d KB\n", |
| isolate_->memory_allocator()->Size() / KB, |
| isolate_->memory_allocator()->Available() / KB); |
| PrintPID("New space, used: %6" V8_PTR_PREFIX "d KB" |
| ", available: %6" V8_PTR_PREFIX "d KB" |
| ", committed: %6" V8_PTR_PREFIX "d KB\n", |
| new_space_.Size() / KB, |
| new_space_.Available() / KB, |
| new_space_.CommittedMemory() / KB); |
| PrintPID("Old pointers, used: %6" V8_PTR_PREFIX "d KB" |
| ", available: %6" V8_PTR_PREFIX "d KB" |
| ", committed: %6" V8_PTR_PREFIX "d KB\n", |
| old_pointer_space_->SizeOfObjects() / KB, |
| old_pointer_space_->Available() / KB, |
| old_pointer_space_->CommittedMemory() / KB); |
| PrintPID("Old data space, used: %6" V8_PTR_PREFIX "d KB" |
| ", available: %6" V8_PTR_PREFIX "d KB" |
| ", committed: %6" V8_PTR_PREFIX "d KB\n", |
| old_data_space_->SizeOfObjects() / KB, |
| old_data_space_->Available() / KB, |
| old_data_space_->CommittedMemory() / KB); |
| PrintPID("Code space, used: %6" V8_PTR_PREFIX "d KB" |
| ", available: %6" V8_PTR_PREFIX "d KB" |
| ", committed: %6" V8_PTR_PREFIX "d KB\n", |
| code_space_->SizeOfObjects() / KB, |
| code_space_->Available() / KB, |
| code_space_->CommittedMemory() / KB); |
| PrintPID("Map space, used: %6" V8_PTR_PREFIX "d KB" |
| ", available: %6" V8_PTR_PREFIX "d KB" |
| ", committed: %6" V8_PTR_PREFIX "d KB\n", |
| map_space_->SizeOfObjects() / KB, |
| map_space_->Available() / KB, |
| map_space_->CommittedMemory() / KB); |
| PrintPID("Cell space, used: %6" V8_PTR_PREFIX "d KB" |
| ", available: %6" V8_PTR_PREFIX "d KB" |
| ", committed: %6" V8_PTR_PREFIX "d KB\n", |
| cell_space_->SizeOfObjects() / KB, |
| cell_space_->Available() / KB, |
| cell_space_->CommittedMemory() / KB); |
| PrintPID("Large object space, used: %6" V8_PTR_PREFIX "d KB" |
| ", available: %6" V8_PTR_PREFIX "d KB" |
| ", committed: %6" V8_PTR_PREFIX "d KB\n", |
| lo_space_->SizeOfObjects() / KB, |
| lo_space_->Available() / KB, |
| lo_space_->CommittedMemory() / KB); |
| } |
| |
| |
| // TODO(1238405): Combine the infrastructure for --heap-stats and |
| // --log-gc to avoid the complicated preprocessor and flag testing. |
| void Heap::ReportStatisticsAfterGC() { |
| // Similar to the before GC, we use some complicated logic to ensure that |
| // NewSpace statistics are logged exactly once when --log-gc is turned on. |
| #if defined(DEBUG) |
| if (FLAG_heap_stats) { |
| new_space_.CollectStatistics(); |
| ReportHeapStatistics("After GC"); |
| } else if (FLAG_log_gc) { |
| new_space_.ReportStatistics(); |
| } |
| #else |
| if (FLAG_log_gc) new_space_.ReportStatistics(); |
| #endif // DEBUG |
| } |
| |
| |
| void Heap::GarbageCollectionPrologue() { |
| isolate_->transcendental_cache()->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 // DEBUG |
| |
| #if defined(DEBUG) |
| ReportStatisticsBeforeGC(); |
| #endif // DEBUG |
| |
| LiveObjectList::GCPrologue(); |
| store_buffer()->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() { |
| store_buffer()->GCEpilogue(); |
| LiveObjectList::GCEpilogue(); |
| #ifdef DEBUG |
| allow_allocation(true); |
| ZapFromSpace(); |
| |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| |
| if (FLAG_print_global_handles) isolate_->global_handles()->Print(); |
| if (FLAG_print_handles) PrintHandles(); |
| if (FLAG_gc_verbose) Print(); |
| if (FLAG_code_stats) ReportCodeStatistics("After GC"); |
| #endif |
| |
| isolate_->counters()->alive_after_last_gc()->Set( |
| static_cast<int>(SizeOfObjects())); |
| |
| isolate_->counters()->symbol_table_capacity()->Set( |
| symbol_table()->Capacity()); |
| isolate_->counters()->number_of_symbols()->Set( |
| symbol_table()->NumberOfElements()); |
| |
| if (CommittedMemory() > 0) { |
| isolate_->counters()->external_fragmentation_total()->AddSample( |
| static_cast<int>(100 - (SizeOfObjects() * 100.0) / CommittedMemory())); |
| } |
| |
| #define UPDATE_COUNTERS_FOR_SPACE(space) \ |
| isolate_->counters()->space##_bytes_available()->Set( \ |
| static_cast<int>(space()->Available())); \ |
| isolate_->counters()->space##_bytes_committed()->Set( \ |
| static_cast<int>(space()->CommittedMemory())); \ |
| isolate_->counters()->space##_bytes_used()->Set( \ |
| static_cast<int>(space()->SizeOfObjects())); |
| #define UPDATE_FRAGMENTATION_FOR_SPACE(space) \ |
| if (space()->CommittedMemory() > 0) { \ |
| isolate_->counters()->external_fragmentation_##space()->AddSample( \ |
| static_cast<int>(100 - \ |
| (space()->SizeOfObjects() * 100.0) / space()->CommittedMemory())); \ |
| } |
| #define UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(space) \ |
| UPDATE_COUNTERS_FOR_SPACE(space) \ |
| UPDATE_FRAGMENTATION_FOR_SPACE(space) |
| |
| UPDATE_COUNTERS_FOR_SPACE(new_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(old_pointer_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(old_data_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(code_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(map_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(cell_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(lo_space) |
| #undef UPDATE_COUNTERS_FOR_SPACE |
| #undef UPDATE_FRAGMENTATION_FOR_SPACE |
| #undef UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE |
| |
| #if defined(DEBUG) |
| ReportStatisticsAfterGC(); |
| #endif // DEBUG |
| #ifdef ENABLE_DEBUGGER_SUPPORT |
| isolate_->debug()->AfterGarbageCollection(); |
| #endif // ENABLE_DEBUGGER_SUPPORT |
| } |
| |
| |
| void Heap::CollectAllGarbage(int flags, const char* gc_reason) { |
| // Since we are ignoring the return value, the exact choice of space does |
| // not matter, so long as we do not specify NEW_SPACE, which would not |
| // cause a full GC. |
| mark_compact_collector_.SetFlags(flags); |
| CollectGarbage(OLD_POINTER_SPACE, gc_reason); |
| mark_compact_collector_.SetFlags(kNoGCFlags); |
| } |
| |
| |
| void Heap::CollectAllAvailableGarbage(const char* gc_reason) { |
| // Since we are ignoring the return value, the exact choice of space does |
| // not matter, so long as we do not specify NEW_SPACE, which would not |
| // cause a full GC. |
| // Major GC would invoke weak handle callbacks on weakly reachable |
| // handles, but won't collect weakly reachable objects until next |
| // major GC. Therefore if we collect aggressively and weak handle callback |
| // has been invoked, we rerun major GC to release objects which become |
| // garbage. |
| // Note: as weak callbacks can execute arbitrary code, we cannot |
| // hope that eventually there will be no weak callbacks invocations. |
| // Therefore stop recollecting after several attempts. |
| mark_compact_collector()->SetFlags(kMakeHeapIterableMask | |
| kReduceMemoryFootprintMask); |
| isolate_->compilation_cache()->Clear(); |
| const int kMaxNumberOfAttempts = 7; |
| for (int attempt = 0; attempt < kMaxNumberOfAttempts; attempt++) { |
| if (!CollectGarbage(OLD_POINTER_SPACE, MARK_COMPACTOR, gc_reason, NULL)) { |
| break; |
| } |
| } |
| mark_compact_collector()->SetFlags(kNoGCFlags); |
| new_space_.Shrink(); |
| UncommitFromSpace(); |
| Shrink(); |
| incremental_marking()->UncommitMarkingDeque(); |
| } |
| |
| |
| bool Heap::CollectGarbage(AllocationSpace space, |
| GarbageCollector collector, |
| const char* gc_reason, |
| const char* collector_reason) { |
| // The VM is in the GC state until exiting this function. |
| VMState state(isolate_, 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 |
| |
| if (collector == SCAVENGER && !incremental_marking()->IsStopped()) { |
| if (FLAG_trace_incremental_marking) { |
| PrintF("[IncrementalMarking] Scavenge during marking.\n"); |
| } |
| } |
| |
| if (collector == MARK_COMPACTOR && |
| !mark_compact_collector()->abort_incremental_marking_ && |
| !incremental_marking()->IsStopped() && |
| !incremental_marking()->should_hurry() && |
| FLAG_incremental_marking_steps) { |
| // Make progress in incremental marking. |
| const intptr_t kStepSizeWhenDelayedByScavenge = 1 * MB; |
| incremental_marking()->Step(kStepSizeWhenDelayedByScavenge, |
| IncrementalMarking::NO_GC_VIA_STACK_GUARD); |
| if (!incremental_marking()->IsComplete()) { |
| if (FLAG_trace_incremental_marking) { |
| PrintF("[IncrementalMarking] Delaying MarkSweep.\n"); |
| } |
| collector = SCAVENGER; |
| collector_reason = "incremental marking delaying mark-sweep"; |
| } |
| } |
| |
| bool next_gc_likely_to_collect_more = false; |
| |
| { GCTracer tracer(this, gc_reason, collector_reason); |
| 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) |
| ? isolate_->counters()->gc_scavenger() |
| : isolate_->counters()->gc_compactor(); |
| rate->Start(); |
| next_gc_likely_to_collect_more = |
| PerformGarbageCollection(collector, &tracer); |
| rate->Stop(); |
| |
| GarbageCollectionEpilogue(); |
| } |
| |
| ASSERT(collector == SCAVENGER || incremental_marking()->IsStopped()); |
| if (incremental_marking()->IsStopped()) { |
| if (incremental_marking()->WorthActivating() && NextGCIsLikelyToBeFull()) { |
| incremental_marking()->Start(); |
| } |
| } |
| |
| return next_gc_likely_to_collect_more; |
| } |
| |
| |
| void Heap::PerformScavenge() { |
| GCTracer tracer(this, NULL, NULL); |
| if (incremental_marking()->IsStopped()) { |
| PerformGarbageCollection(SCAVENGER, &tracer); |
| } else { |
| PerformGarbageCollection(MARK_COMPACTOR, &tracer); |
| } |
| } |
| |
| |
| #ifdef DEBUG |
| // Helper class for verifying the symbol table. |
| class SymbolTableVerifier : public ObjectVisitor { |
| public: |
| 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)->IsTheHole() || (*p)->IsUndefined() || (*p)->IsSymbol()); |
| } |
| } |
| } |
| }; |
| #endif // DEBUG |
| |
| |
| static void VerifySymbolTable() { |
| #ifdef DEBUG |
| SymbolTableVerifier verifier; |
| HEAP->symbol_table()->IterateElements(&verifier); |
| #endif // DEBUG |
| } |
| |
| |
| static bool AbortIncrementalMarkingAndCollectGarbage( |
| Heap* heap, |
| AllocationSpace space, |
| const char* gc_reason = NULL) { |
| heap->mark_compact_collector()->SetFlags(Heap::kAbortIncrementalMarkingMask); |
| bool result = heap->CollectGarbage(space, gc_reason); |
| heap->mark_compact_collector()->SetFlags(Heap::kNoGCFlags); |
| return result; |
| } |
| |
| |
| 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; |
| int counter = 0; |
| static const int kThreshold = 20; |
| while (gc_performed && counter++ < kThreshold) { |
| gc_performed = false; |
| if (!new_space->ReserveSpace(new_space_size)) { |
| Heap::CollectGarbage(NEW_SPACE, |
| "failed to reserve space in the new space"); |
| gc_performed = true; |
| } |
| if (!old_pointer_space->ReserveSpace(pointer_space_size)) { |
| AbortIncrementalMarkingAndCollectGarbage(this, OLD_POINTER_SPACE, |
| "failed to reserve space in the old pointer space"); |
| gc_performed = true; |
| } |
| if (!(old_data_space->ReserveSpace(data_space_size))) { |
| AbortIncrementalMarkingAndCollectGarbage(this, OLD_DATA_SPACE, |
| "failed to reserve space in the old data space"); |
| gc_performed = true; |
| } |
| if (!(code_space->ReserveSpace(code_space_size))) { |
| AbortIncrementalMarkingAndCollectGarbage(this, CODE_SPACE, |
| "failed to reserve space in the code space"); |
| gc_performed = true; |
| } |
| if (!(map_space->ReserveSpace(map_space_size))) { |
| AbortIncrementalMarkingAndCollectGarbage(this, MAP_SPACE, |
| "failed to reserve space in the map space"); |
| gc_performed = true; |
| } |
| if (!(cell_space->ReserveSpace(cell_space_size))) { |
| AbortIncrementalMarkingAndCollectGarbage(this, CELL_SPACE, |
| "failed to reserve space in the 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))) { |
| AbortIncrementalMarkingAndCollectGarbage(this, LO_SPACE, |
| "failed to reserve space in the large object space"); |
| gc_performed = true; |
| } |
| } |
| |
| if (gc_performed) { |
| // Failed to reserve the space after several attempts. |
| V8::FatalProcessOutOfMemory("Heap::ReserveSpace"); |
| } |
| } |
| |
| |
| void Heap::EnsureFromSpaceIsCommitted() { |
| if (new_space_.CommitFromSpaceIfNeeded()) return; |
| |
| // Committing memory to from space failed. |
| // Try shrinking and try again. |
| 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 (isolate_->bootstrapper()->IsActive()) return; |
| |
| Object* context = global_contexts_list_; |
| while (!context->IsUndefined()) { |
| // Get the caches for this context. GC can happen when the context |
| // is not fully initialized, so the caches can be undefined. |
| Object* caches_or_undefined = |
| Context::cast(context)->get(Context::JSFUNCTION_RESULT_CACHES_INDEX); |
| if (!caches_or_undefined->IsUndefined()) { |
| FixedArray* caches = FixedArray::cast(caches_or_undefined); |
| // 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 (isolate_->bootstrapper()->IsActive() && |
| !incremental_marking()->IsMarking()) { |
| return; |
| } |
| |
| Object* context = global_contexts_list_; |
| while (!context->IsUndefined()) { |
| // GC can happen when the context is not fully initialized, |
| // so the cache can be undefined. |
| Object* cache = |
| Context::cast(context)->get(Context::NORMALIZED_MAP_CACHE_INDEX); |
| if (!cache->IsUndefined()) { |
| NormalizedMapCache::cast(cache)->Clear(); |
| } |
| context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK); |
| } |
| } |
| |
| |
| 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 > kYoungSurvivalRateHighThreshold) { |
| high_survival_rate_period_length_++; |
| } else { |
| high_survival_rate_period_length_ = 0; |
| } |
| |
| if (survival_rate < kYoungSurvivalRateLowThreshold) { |
| low_survival_rate_period_length_++; |
| } else { |
| low_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(isolate_, CodeMovingGCEvent()); |
| } |
| |
| if (FLAG_verify_heap) { |
| 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 (IsHighSurvivalRate()) { |
| // We speed up the incremental marker if it is running so that it |
| // does not fall behind the rate of promotion, which would cause a |
| // constantly growing old space. |
| incremental_marking()->NotifyOfHighPromotionRate(); |
| } |
| |
| if (collector == MARK_COMPACTOR) { |
| // Perform mark-sweep with optional compaction. |
| MarkCompact(tracer); |
| sweep_generation_++; |
| bool high_survival_rate_during_scavenges = IsHighSurvivalRate() && |
| IsStableOrIncreasingSurvivalTrend(); |
| |
| UpdateSurvivalRateTrend(start_new_space_size); |
| |
| size_of_old_gen_at_last_old_space_gc_ = PromotedSpaceSizeOfObjects(); |
| |
| 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_limit_factor_ = 2; |
| } else { |
| old_gen_limit_factor_ = 1; |
| } |
| |
| old_gen_promotion_limit_ = |
| OldGenPromotionLimit(size_of_old_gen_at_last_old_space_gc_); |
| old_gen_allocation_limit_ = |
| OldGenAllocationLimit(size_of_old_gen_at_last_old_space_gc_); |
| |
| old_gen_exhausted_ = false; |
| } else { |
| tracer_ = tracer; |
| Scavenge(); |
| tracer_ = NULL; |
| |
| UpdateSurvivalRateTrend(start_new_space_size); |
| } |
| |
| if (!new_space_high_promotion_mode_active_ && |
| new_space_.Capacity() == new_space_.MaximumCapacity() && |
| IsStableOrIncreasingSurvivalTrend() && |
| IsHighSurvivalRate()) { |
| // Stable high survival rates even though young generation is at |
| // maximum capacity indicates that most objects will be promoted. |
| // To decrease scavenger pauses and final mark-sweep pauses, we |
| // have to limit maximal capacity of the young generation. |
| new_space_high_promotion_mode_active_ = true; |
| if (FLAG_trace_gc) { |
| PrintPID("Limited new space size due to high promotion rate: %d MB\n", |
| new_space_.InitialCapacity() / MB); |
| } |
| } else if (new_space_high_promotion_mode_active_ && |
| IsStableOrDecreasingSurvivalTrend() && |
| IsLowSurvivalRate()) { |
| // Decreasing low survival rates might indicate that the above high |
| // promotion mode is over and we should allow the young generation |
| // to grow again. |
| new_space_high_promotion_mode_active_ = false; |
| if (FLAG_trace_gc) { |
| PrintPID("Unlimited new space size due to low promotion rate: %d MB\n", |
| new_space_.MaximumCapacity() / MB); |
| } |
| } |
| |
| if (new_space_high_promotion_mode_active_ && |
| new_space_.Capacity() > new_space_.InitialCapacity()) { |
| new_space_.Shrink(); |
| } |
| |
| isolate_->counters()->objs_since_last_young()->Set(0); |
| |
| gc_post_processing_depth_++; |
| { DisableAssertNoAllocation allow_allocation; |
| GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL); |
| next_gc_likely_to_collect_more = |
| isolate_->global_handles()->PostGarbageCollectionProcessing(collector); |
| } |
| gc_post_processing_depth_--; |
| |
| // 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 = 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_(); |
| } |
| if (FLAG_verify_heap) { |
| VerifySymbolTable(); |
| } |
| |
| return next_gc_likely_to_collect_more; |
| } |
| |
| |
| void Heap::MarkCompact(GCTracer* tracer) { |
| gc_state_ = MARK_COMPACT; |
| LOG(isolate_, ResourceEvent("markcompact", "begin")); |
| |
| mark_compact_collector_.Prepare(tracer); |
| |
| ms_count_++; |
| tracer->set_full_gc_count(ms_count_); |
| |
| MarkCompactPrologue(); |
| |
| mark_compact_collector_.CollectGarbage(); |
| |
| LOG(isolate_, ResourceEvent("markcompact", "end")); |
| |
| gc_state_ = NOT_IN_GC; |
| |
| isolate_->counters()->objs_since_last_full()->Set(0); |
| |
| contexts_disposed_ = 0; |
| |
| isolate_->set_context_exit_happened(false); |
| } |
| |
| |
| void Heap::MarkCompactPrologue() { |
| // At any old GC clear the keyed lookup cache to enable collection of unused |
| // maps. |
| isolate_->keyed_lookup_cache()->Clear(); |
| isolate_->context_slot_cache()->Clear(); |
| isolate_->descriptor_lookup_cache()->Clear(); |
| StringSplitCache::Clear(string_split_cache()); |
| |
| isolate_->compilation_cache()->MarkCompactPrologue(); |
| |
| CompletelyClearInstanceofCache(); |
| |
| FlushNumberStringCache(); |
| if (FLAG_cleanup_code_caches_at_gc) { |
| polymorphic_code_cache()->set_cache(undefined_value()); |
| } |
| |
| ClearNormalizedMapCaches(); |
| } |
| |
| |
| Object* Heap::FindCodeObject(Address a) { |
| return isolate()->inner_pointer_to_code_cache()-> |
| GcSafeFindCodeForInnerPointer(a); |
| } |
| |
| |
| // Helper class for copying HeapObjects |
| class ScavengeVisitor: public ObjectVisitor { |
| public: |
| explicit ScavengeVisitor(Heap* heap) : heap_(heap) {} |
| |
| 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)); |
| } |
| |
| Heap* heap_; |
| }; |
| |
| |
| #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); |
| |
| // The old data space was normally swept conservatively so that the iterator |
| // doesn't work, so we normally skip the next bit. |
| if (!HEAP->old_data_space()->was_swept_conservatively()) { |
| 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() && |
| !new_space_high_promotion_mode_active_) { |
| // Grow the size of new space if there is room to grow, enough data |
| // has survived scavenge since the last expansion and we are not in |
| // high promotion mode. |
| new_space_.Grow(); |
| survived_since_last_expansion_ = 0; |
| } |
| } |
| |
| |
| static bool IsUnscavengedHeapObject(Heap* heap, Object** p) { |
| return heap->InNewSpace(*p) && |
| !HeapObject::cast(*p)->map_word().IsForwardingAddress(); |
| } |
| |
| |
| void Heap::ScavengeStoreBufferCallback( |
| Heap* heap, |
| MemoryChunk* page, |
| StoreBufferEvent event) { |
| heap->store_buffer_rebuilder_.Callback(page, event); |
| } |
| |
| |
| void StoreBufferRebuilder::Callback(MemoryChunk* page, StoreBufferEvent event) { |
| if (event == kStoreBufferStartScanningPagesEvent) { |
| start_of_current_page_ = NULL; |
| current_page_ = NULL; |
| } else if (event == kStoreBufferScanningPageEvent) { |
| if (current_page_ != NULL) { |
| // If this page already overflowed the store buffer during this iteration. |
| if (current_page_->scan_on_scavenge()) { |
| // Then we should wipe out the entries that have been added for it. |
| store_buffer_->SetTop(start_of_current_page_); |
| } else if (store_buffer_->Top() - start_of_current_page_ >= |
| (store_buffer_->Limit() - store_buffer_->Top()) >> 2) { |
| // Did we find too many pointers in the previous page? The heuristic is |
| // that no page can take more then 1/5 the remaining slots in the store |
| // buffer. |
| current_page_->set_scan_on_scavenge(true); |
| store_buffer_->SetTop(start_of_current_page_); |
| } else { |
| // In this case the page we scanned took a reasonable number of slots in |
| // the store buffer. It has now been rehabilitated and is no longer |
| // marked scan_on_scavenge. |
| ASSERT(!current_page_->scan_on_scavenge()); |
| } |
| } |
| start_of_current_page_ = store_buffer_->Top(); |
| current_page_ = page; |
| } else if (event == kStoreBufferFullEvent) { |
| // The current page overflowed the store buffer again. Wipe out its entries |
| // in the store buffer and mark it scan-on-scavenge again. This may happen |
| // several times while scanning. |
| if (current_page_ == NULL) { |
| // Store Buffer overflowed while scanning promoted objects. These are not |
| // in any particular page, though they are likely to be clustered by the |
| // allocation routines. |
| store_buffer_->EnsureSpace(StoreBuffer::kStoreBufferSize); |
| } else { |
| // Store Buffer overflowed while scanning a particular old space page for |
| // pointers to new space. |
| ASSERT(current_page_ == page); |
| ASSERT(page != NULL); |
| current_page_->set_scan_on_scavenge(true); |
| ASSERT(start_of_current_page_ != store_buffer_->Top()); |
| store_buffer_->SetTop(start_of_current_page_); |
| } |
| } else { |
| UNREACHABLE(); |
| } |
| } |
| |
| |
| void PromotionQueue::Initialize() { |
| // Assumes that a NewSpacePage exactly fits a number of promotion queue |
| // entries (where each is a pair of intptr_t). This allows us to simplify |
| // the test fpr when to switch pages. |
| ASSERT((Page::kPageSize - MemoryChunk::kBodyOffset) % (2 * kPointerSize) |
| == 0); |
| limit_ = reinterpret_cast<intptr_t*>(heap_->new_space()->ToSpaceStart()); |
| front_ = rear_ = |
| reinterpret_cast<intptr_t*>(heap_->new_space()->ToSpaceEnd()); |
| emergency_stack_ = NULL; |
| guard_ = false; |
| } |
| |
| |
| void PromotionQueue::RelocateQueueHead() { |
| ASSERT(emergency_stack_ == NULL); |
| |
| Page* p = Page::FromAllocationTop(reinterpret_cast<Address>(rear_)); |
| intptr_t* head_start = rear_; |
| intptr_t* head_end = |
| Min(front_, reinterpret_cast<intptr_t*>(p->area_end())); |
| |
| int entries_count = |
| static_cast<int>(head_end - head_start) / kEntrySizeInWords; |
| |
| emergency_stack_ = new List<Entry>(2 * entries_count); |
| |
| while (head_start != head_end) { |
| int size = static_cast<int>(*(head_start++)); |
| HeapObject* obj = reinterpret_cast<HeapObject*>(*(head_start++)); |
| emergency_stack_->Add(Entry(obj, size)); |
| } |
| rear_ = head_end; |
| } |
| |
| |
| class ScavengeWeakObjectRetainer : public WeakObjectRetainer { |
| public: |
| explicit ScavengeWeakObjectRetainer(Heap* heap) : heap_(heap) { } |
| |
| virtual Object* RetainAs(Object* object) { |
| if (!heap_->InFromSpace(object)) { |
| return object; |
| } |
| |
| MapWord map_word = HeapObject::cast(object)->map_word(); |
| if (map_word.IsForwardingAddress()) { |
| return map_word.ToForwardingAddress(); |
| } |
| return NULL; |
| } |
| |
| private: |
| Heap* heap_; |
| }; |
| |
| |
| void Heap::Scavenge() { |
| RelocationLock relocation_lock(this); |
| #ifdef DEBUG |
| if (FLAG_verify_heap) VerifyNonPointerSpacePointers(); |
| #endif |
| |
| gc_state_ = SCAVENGE; |
| |
| // Implements Cheney's copying algorithm |
| LOG(isolate_, ResourceEvent("scavenge", "begin")); |
| |
| // Clear descriptor cache. |
| isolate_->descriptor_lookup_cache()->Clear(); |
| |
| // Used for updating survived_since_last_expansion_ at function end. |
| intptr_t survived_watermark = PromotedSpaceSizeOfObjects(); |
| |
| CheckNewSpaceExpansionCriteria(); |
| |
| SelectScavengingVisitorsTable(); |
| |
| incremental_marking()->PrepareForScavenge(); |
| |
| AdvanceSweepers(static_cast<int>(new_space_.Size())); |
| |
| // Flip the semispaces. After flipping, to space is empty, from space has |
| // live objects. |
| new_space_.Flip(); |
| new_space_.ResetAllocationInfo(); |
| |
| // We need to sweep newly copied objects which can be either in the |
| // to space or promoted to the old generation. For to-space |
| // objects, we treat the bottom of the to space as a queue. Newly |
| // copied and unswept objects lie between a 'front' mark and the |
| // allocation pointer. |
| // |
| // Promoted objects can go into various old-generation spaces, and |
| // can be allocated internally in the spaces (from the free list). |
| // We treat the top of the to space as a queue of addresses of |
| // promoted objects. The addresses of newly promoted and unswept |
| // objects lie between a 'front' mark and a 'rear' mark that is |
| // updated as a side effect of promoting an object. |
| // |
| // There is guaranteed to be enough room at the top of the to space |
| // for the addresses of promoted objects: every object promoted |
| // frees up its size in bytes from the top of the new space, and |
| // objects are at least one pointer in size. |
| Address new_space_front = new_space_.ToSpaceStart(); |
| promotion_queue_.Initialize(); |
| |
| #ifdef DEBUG |
| store_buffer()->Clean(); |
| #endif |
| |
| ScavengeVisitor scavenge_visitor(this); |
| // Copy roots. |
| IterateRoots(&scavenge_visitor, VISIT_ALL_IN_SCAVENGE); |
| |
| // Copy objects reachable from the old generation. |
| { |
| StoreBufferRebuildScope scope(this, |
| store_buffer(), |
| &ScavengeStoreBufferCallback); |
| store_buffer()->IteratePointersToNewSpace(&ScavengeObject); |
| } |
| |
| // 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_)); |
| |
| new_space_front = DoScavenge(&scavenge_visitor, new_space_front); |
| isolate_->global_handles()->IdentifyNewSpaceWeakIndependentHandles( |
| &IsUnscavengedHeapObject); |
| isolate_->global_handles()->IterateNewSpaceWeakIndependentRoots( |
| &scavenge_visitor); |
| new_space_front = DoScavenge(&scavenge_visitor, new_space_front); |
| |
| UpdateNewSpaceReferencesInExternalStringTable( |
| &UpdateNewSpaceReferenceInExternalStringTableEntry); |
| |
| promotion_queue_.Destroy(); |
| |
| LiveObjectList::UpdateReferencesForScavengeGC(); |
| if (!FLAG_watch_ic_patching) { |
| isolate()->runtime_profiler()->UpdateSamplesAfterScavenge(); |
| } |
| incremental_marking()->UpdateMarkingDequeAfterScavenge(); |
| |
| ScavengeWeakObjectRetainer weak_object_retainer(this); |
| ProcessWeakReferences(&weak_object_retainer); |
| |
| ASSERT(new_space_front == new_space_.top()); |
| |
| // Set age mark. |
| new_space_.set_age_mark(new_space_.top()); |
| |
| new_space_.LowerInlineAllocationLimit( |
| new_space_.inline_allocation_limit_step()); |
| |
| // Update how much has survived scavenge. |
| IncrementYoungSurvivorsCounter(static_cast<int>( |
| (PromotedSpaceSizeOfObjects() - survived_watermark) + new_space_.Size())); |
| |
| LOG(isolate_, ResourceEvent("scavenge", "end")); |
| |
| gc_state_ = NOT_IN_GC; |
| |
| scavenges_since_last_idle_round_++; |
| } |
| |
| |
| String* Heap::UpdateNewSpaceReferenceInExternalStringTableEntry(Heap* heap, |
| Object** p) { |
| MapWord first_word = HeapObject::cast(*p)->map_word(); |
| |
| if (!first_word.IsForwardingAddress()) { |
| // Unreachable external string can be finalized. |
| heap->FinalizeExternalString(String::cast(*p)); |
| return NULL; |
| } |
| |
| // String is still reachable. |
| return String::cast(first_word.ToForwardingAddress()); |
| } |
| |
| |
| void Heap::UpdateNewSpaceReferencesInExternalStringTable( |
| ExternalStringTableUpdaterCallback updater_func) { |
| if (FLAG_verify_heap) { |
| external_string_table_.Verify(); |
| } |
| |
| if (external_string_table_.new_space_strings_.is_empty()) return; |
| |
| Object** start = &external_string_table_.new_space_strings_[0]; |
| Object** end = start + external_string_table_.new_space_strings_.length(); |
| Object** last = start; |
| |
| for (Object** p = start; p < end; ++p) { |
| ASSERT(InFromSpace(*p)); |
| String* target = updater_func(this, p); |
| |
| if (target == NULL) continue; |
| |
| ASSERT(target->IsExternalString()); |
| |
| if (InNewSpace(target)) { |
| // String is still in new space. Update the table entry. |
| *last = target; |
| ++last; |
| } else { |
| // String got promoted. Move it to the old string list. |
| external_string_table_.AddOldString(target); |
| } |
| } |
| |
| ASSERT(last <= end); |
| external_string_table_.ShrinkNewStrings(static_cast<int>(last - start)); |
| } |
| |
| |
| void Heap::UpdateReferencesInExternalStringTable( |
| ExternalStringTableUpdaterCallback updater_func) { |
| |
| // Update old space string references. |
| if (external_string_table_.old_space_strings_.length() > 0) { |
| Object** start = &external_string_table_.old_space_strings_[0]; |
| Object** end = start + external_string_table_.old_space_strings_.length(); |
| for (Object** p = start; p < end; ++p) *p = updater_func(this, p); |
| } |
| |
| UpdateNewSpaceReferencesInExternalStringTable(updater_func); |
| } |
| |
| |
| static Object* ProcessFunctionWeakReferences(Heap* heap, |
| Object* function, |
| WeakObjectRetainer* retainer, |
| bool record_slots) { |
| Object* undefined = heap->undefined_value(); |
| Object* head = undefined; |
| JSFunction* tail = NULL; |
| Object* candidate = function; |
| while (candidate != undefined) { |
| // 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 == undefined) { |
| // First element in the list. |
| head = retain; |
| } else { |
| // Subsequent elements in the list. |
| ASSERT(tail != NULL); |
| tail->set_next_function_link(retain); |
| if (record_slots) { |
| Object** next_function = |
| HeapObject::RawField(tail, JSFunction::kNextFunctionLinkOffset); |
| heap->mark_compact_collector()->RecordSlot( |
| next_function, next_function, retain); |
| } |
| } |
| // Retained function is new tail. |
| candidate_function = reinterpret_cast<JSFunction*>(retain); |
| tail = candidate_function; |
| |
| ASSERT(retain->IsUndefined() || retain->IsJSFunction()); |
| |
| if (retain == undefined) break; |
| } |
| |
| // 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(undefined); |
| } |
| |
| return head; |
| } |
| |
| |
| void Heap::ProcessWeakReferences(WeakObjectRetainer* retainer) { |
| Object* undefined = undefined_value(); |
| Object* head = undefined; |
| Context* tail = NULL; |
| Object* candidate = global_contexts_list_; |
| |
| // We don't record weak slots during marking or scavenges. |
| // Instead we do it once when we complete mark-compact cycle. |
| // Note that write barrier has no effect if we are already in the middle of |
| // compacting mark-sweep cycle and we have to record slots manually. |
| bool record_slots = |
| gc_state() == MARK_COMPACT && |
| mark_compact_collector()->is_compacting(); |
| |
| while (candidate != undefined) { |
| // 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 == undefined) { |
| // First element in the list. |
| head = retain; |
| } else { |
| // Subsequent elements in the list. |
| ASSERT(tail != NULL); |
| tail->set_unchecked(this, |
| Context::NEXT_CONTEXT_LINK, |
| retain, |
| UPDATE_WRITE_BARRIER); |
| |
| if (record_slots) { |
| Object** next_context = |
| HeapObject::RawField( |
| tail, FixedArray::SizeFor(Context::NEXT_CONTEXT_LINK)); |
| mark_compact_collector()->RecordSlot( |
| next_context, next_context, retain); |
| } |
| } |
| // Retained context is new tail. |
| candidate_context = reinterpret_cast<Context*>(retain); |
| tail = candidate_context; |
| |
| if (retain == undefined) break; |
| |
| // Process the weak list of optimized functions for the context. |
| Object* function_list_head = |
| ProcessFunctionWeakReferences( |
| this, |
| candidate_context->get(Context::OPTIMIZED_FUNCTIONS_LIST), |
| retainer, |
| record_slots); |
| candidate_context->set_unchecked(this, |
| Context::OPTIMIZED_FUNCTIONS_LIST, |
| function_list_head, |
| UPDATE_WRITE_BARRIER); |
| if (record_slots) { |
| Object** optimized_functions = |
| HeapObject::RawField( |
| tail, FixedArray::SizeFor(Context::OPTIMIZED_FUNCTIONS_LIST)); |
| mark_compact_collector()->RecordSlot( |
| optimized_functions, optimized_functions, function_list_head); |
| } |
| } |
| |
| // 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(this, |
| Context::NEXT_CONTEXT_LINK, |
| Heap::undefined_value(), |
| UPDATE_WRITE_BARRIER); |
| } |
| |
| // Update the head of the list of contexts. |
| global_contexts_list_ = head; |
| } |
| |
| |
| void Heap::VisitExternalResources(v8::ExternalResourceVisitor* visitor) { |
| AssertNoAllocation no_allocation; |
| |
| class VisitorAdapter : public ObjectVisitor { |
| public: |
| explicit VisitorAdapter(v8::ExternalResourceVisitor* visitor) |
| : visitor_(visitor) {} |
| virtual void VisitPointers(Object** start, Object** end) { |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsExternalString()) { |
| visitor_->VisitExternalString(Utils::ToLocal( |
| Handle<String>(String::cast(*p)))); |
| } |
| } |
| } |
| private: |
| v8::ExternalResourceVisitor* visitor_; |
| } visitor_adapter(visitor); |
| external_string_table_.Iterate(&visitor_adapter); |
| } |
| |
| |
| class NewSpaceScavenger : public StaticNewSpaceVisitor<NewSpaceScavenger> { |
| public: |
| static inline void VisitPointer(Heap* heap, 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 { |
| SemiSpace::AssertValidRange(new_space_front, new_space_.top()); |
| // The addresses new_space_front and new_space_.top() define a |
| // queue of unprocessed copied objects. Process them until the |
| // queue is empty. |
| while (new_space_front != new_space_.top()) { |
| if (!NewSpacePage::IsAtEnd(new_space_front)) { |
| HeapObject* object = HeapObject::FromAddress(new_space_front); |
| new_space_front += |
| NewSpaceScavenger::IterateBody(object->map(), object); |
| } else { |
| new_space_front = |
| NewSpacePage::FromLimit(new_space_front)->next_page()->area_start(); |
| } |
| } |
| |
| // Promote and process all the to-be-promoted objects. |
| { |
| StoreBufferRebuildScope scope(this, |
| store_buffer(), |
| &ScavengeStoreBufferCallback); |
| while (!promotion_queue()->is_empty()) { |
| HeapObject* target; |
| int size; |
| promotion_queue()->remove(&target, &size); |
| |
| // Promoted object might be already partially visited |
| // during old space pointer 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, |
| &ScavengeObject); |
| } |
| } |
| |
| // Take another spin if there are now unswept objects in new space |
| // (there are currently no more unswept promoted objects). |
| } while (new_space_front != new_space_.top()); |
| |
| return new_space_front; |
| } |
| |
| |
| STATIC_ASSERT((FixedDoubleArray::kHeaderSize & kDoubleAlignmentMask) == 0); |
| |
| |
| INLINE(static HeapObject* EnsureDoubleAligned(Heap* heap, |
| HeapObject* object, |
| int size)); |
| |
| static HeapObject* EnsureDoubleAligned(Heap* heap, |
| HeapObject* object, |
| int size) { |
| if ((OffsetFrom(object->address()) & kDoubleAlignmentMask) != 0) { |
| heap->CreateFillerObjectAt(object->address(), kPointerSize); |
| return HeapObject::FromAddress(object->address() + kPointerSize); |
| } else { |
| heap->CreateFillerObjectAt(object->address() + size - kPointerSize, |
| kPointerSize); |
| return object; |
| } |
| } |
| |
| |
| enum LoggingAndProfiling { |
| LOGGING_AND_PROFILING_ENABLED, |
| LOGGING_AND_PROFILING_DISABLED |
| }; |
| |
| |
| enum MarksHandling { TRANSFER_MARKS, IGNORE_MARKS }; |
| |
| |
| template<MarksHandling marks_handling, |
| LoggingAndProfiling logging_and_profiling_mode> |
| 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(kVisitFixedDoubleArray, &EvacuateFixedDoubleArray); |
| |
| table_.Register(kVisitGlobalContext, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| template VisitSpecialized<Context::kSize>); |
| |
| table_.Register(kVisitConsString, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| template VisitSpecialized<ConsString::kSize>); |
| |
| table_.Register(kVisitSlicedString, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| template VisitSpecialized<SlicedString::kSize>); |
| |
| table_.Register(kVisitSharedFunctionInfo, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| template VisitSpecialized<SharedFunctionInfo::kSize>); |
| |
| table_.Register(kVisitJSWeakMap, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| Visit); |
| |
| table_.Register(kVisitJSRegExp, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| Visit); |
| |
| if (marks_handling == IGNORE_MARKS) { |
| table_.Register(kVisitJSFunction, |
| &ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| template VisitSpecialized<JSFunction::kSize>); |
| } else { |
| table_.Register(kVisitJSFunction, &EvacuateJSFunction); |
| } |
| |
| table_.RegisterSpecializations<ObjectEvacuationStrategy<DATA_OBJECT>, |
| kVisitDataObject, |
| kVisitDataObjectGeneric>(); |
| |
| table_.RegisterSpecializations<ObjectEvacuationStrategy<POINTER_OBJECT>, |
| kVisitJSObject, |
| kVisitJSObjectGeneric>(); |
| |
| table_.RegisterSpecializations<ObjectEvacuationStrategy<POINTER_OBJECT>, |
| kVisitStruct, |
| kVisitStructGeneric>(); |
| } |
| |
| static VisitorDispatchTable<ScavengingCallback>* GetTable() { |
| return &table_; |
| } |
| |
| private: |
| enum ObjectContents { DATA_OBJECT, POINTER_OBJECT }; |
| enum SizeRestriction { SMALL, UNKNOWN_SIZE }; |
| |
| static void RecordCopiedObject(Heap* heap, HeapObject* obj) { |
| bool should_record = false; |
| #ifdef DEBUG |
| should_record = FLAG_heap_stats; |
| #endif |
| should_record = should_record || FLAG_log_gc; |
| if (should_record) { |
| if (heap->new_space()->Contains(obj)) { |
| heap->new_space()->RecordAllocation(obj); |
| } else { |
| heap->new_space()->RecordPromotion(obj); |
| } |
| } |
| } |
| |
| // 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 void MigrateObject(Heap* heap, |
| 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 (logging_and_profiling_mode == LOGGING_AND_PROFILING_ENABLED) { |
| // Update NewSpace stats if necessary. |
| RecordCopiedObject(heap, target); |
| HEAP_PROFILE(heap, ObjectMoveEvent(source->address(), target->address())); |
| Isolate* isolate = heap->isolate(); |
| if (isolate->logger()->is_logging() || |
| CpuProfiler::is_profiling(isolate)) { |
| if (target->IsSharedFunctionInfo()) { |
| PROFILE(isolate, SharedFunctionInfoMoveEvent( |
| source->address(), target->address())); |
| } |
| } |
| } |
| |
| if (marks_handling == TRANSFER_MARKS) { |
| if (Marking::TransferColor(source, target)) { |
| MemoryChunk::IncrementLiveBytesFromGC(target->address(), size); |
| } |
| } |
| } |
| |
| |
| template<ObjectContents object_contents, |
| SizeRestriction size_restriction, |
| int alignment> |
| static inline void EvacuateObject(Map* map, |
| HeapObject** slot, |
| HeapObject* object, |
| int object_size) { |
| SLOW_ASSERT((size_restriction != SMALL) || |
| (object_size <= Page::kMaxNonCodeHeapObjectSize)); |
| SLOW_ASSERT(object->Size() == object_size); |
| |
| int allocation_size = object_size; |
| if (alignment != kObjectAlignment) { |
| ASSERT(alignment == kDoubleAlignment); |
| allocation_size += kPointerSize; |
| } |
| |
| Heap* heap = map->GetHeap(); |
| if (heap->ShouldBePromoted(object->address(), object_size)) { |
| MaybeObject* maybe_result; |
| |
| if ((size_restriction != SMALL) && |
| (allocation_size > Page::kMaxNonCodeHeapObjectSize)) { |
| maybe_result = heap->lo_space()->AllocateRaw(allocation_size, |
| NOT_EXECUTABLE); |
| } else { |
| if (object_contents == DATA_OBJECT) { |
| maybe_result = heap->old_data_space()->AllocateRaw(allocation_size); |
| } else { |
| maybe_result = |
| heap->old_pointer_space()->AllocateRaw(allocation_size); |
| } |
| } |
| |
| Object* result = NULL; // Initialization to please compiler. |
| if (maybe_result->ToObject(&result)) { |
| HeapObject* target = HeapObject::cast(result); |
| |
| if (alignment != kObjectAlignment) { |
| target = EnsureDoubleAligned(heap, target, allocation_size); |
| } |
| |
| // Order is important: slot might be inside of the target if target |
| // was allocated over a dead object and slot comes from the store |
| // buffer. |
| *slot = target; |
| MigrateObject(heap, object, target, object_size); |
| |
| if (object_contents == POINTER_OBJECT) { |
| if (map->instance_type() == JS_FUNCTION_TYPE) { |
| heap->promotion_queue()->insert( |
| target, JSFunction::kNonWeakFieldsEndOffset); |
| } else { |
| heap->promotion_queue()->insert(target, object_size); |
| } |
| } |
| |
| heap->tracer()->increment_promoted_objects_size(object_size); |
| return; |
| } |
| } |
| MaybeObject* allocation = heap->new_space()->AllocateRaw(allocation_size); |
| heap->promotion_queue()->SetNewLimit(heap->new_space()->top()); |
| Object* result = allocation->ToObjectUnchecked(); |
| HeapObject* target = HeapObject::cast(result); |
| |
| if (alignment != kObjectAlignment) { |
| target = EnsureDoubleAligned(heap, target, allocation_size); |
| } |
| |
| // Order is important: slot might be inside of the target if target |
| // was allocated over a dead object and slot comes from the store |
| // buffer. |
| *slot = target; |
| MigrateObject(heap, object, target, object_size); |
| return; |
| } |
| |
| |
| static inline void EvacuateJSFunction(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| ObjectEvacuationStrategy<POINTER_OBJECT>:: |
| template VisitSpecialized<JSFunction::kSize>(map, slot, object); |
| |
| HeapObject* target = *slot; |
| MarkBit mark_bit = Marking::MarkBitFrom(target); |
| if (Marking::IsBlack(mark_bit)) { |
| // This object is black and it might not be rescanned by marker. |
| // We should explicitly record code entry slot for compaction because |
| // promotion queue processing (IterateAndMarkPointersToFromSpace) will |
| // miss it as it is not HeapObject-tagged. |
| Address code_entry_slot = |
| target->address() + JSFunction::kCodeEntryOffset; |
| Code* code = Code::cast(Code::GetObjectFromEntryAddress(code_entry_slot)); |
| map->GetHeap()->mark_compact_collector()-> |
| RecordCodeEntrySlot(code_entry_slot, code); |
| } |
| } |
| |
| |
| static inline void EvacuateFixedArray(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| int object_size = FixedArray::BodyDescriptor::SizeOf(map, object); |
| EvacuateObject<POINTER_OBJECT, UNKNOWN_SIZE, kObjectAlignment>(map, |
| slot, |
| object, |
| object_size); |
| } |
| |
| |
| static inline void EvacuateFixedDoubleArray(Map* map, |
| HeapObject** slot, |
| HeapObject* object) { |
| int length = reinterpret_cast<FixedDoubleArray*>(object)->length(); |
| int object_size = FixedDoubleArray::SizeFor(length); |
| EvacuateObject<DATA_OBJECT, UNKNOWN_SIZE, kDoubleAlignment>( |
| 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, kObjectAlignment>( |
| 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, kObjectAlignment>( |
| 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, kObjectAlignment>( |
| 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())); |
| |
| Heap* heap = map->GetHeap(); |
| |
| if (marks_handling == IGNORE_MARKS && |
| 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; |
| } |
| |
| heap->DoScavengeObject(first->map(), slot, first); |
| object->set_map_word(MapWord::FromForwardingAddress(*slot)); |
| return; |
| } |
| |
| int object_size = ConsString::kSize; |
| EvacuateObject<POINTER_OBJECT, SMALL, kObjectAlignment>( |
| 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, kObjectAlignment>( |
| 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, kObjectAlignment>( |
| map, slot, object, object_size); |
| } |
| }; |
| |
| static VisitorDispatchTable<ScavengingCallback> table_; |
| }; |
| |
| |
| template<MarksHandling marks_handling, |
| LoggingAndProfiling logging_and_profiling_mode> |
| VisitorDispatchTable<ScavengingCallback> |
| ScavengingVisitor<marks_handling, logging_and_profiling_mode>::table_; |
| |
| |
| static void InitializeScavengingVisitorsTables() { |
| ScavengingVisitor<TRANSFER_MARKS, |
| LOGGING_AND_PROFILING_DISABLED>::Initialize(); |
| ScavengingVisitor<IGNORE_MARKS, LOGGING_AND_PROFILING_DISABLED>::Initialize(); |
| ScavengingVisitor<TRANSFER_MARKS, |
| LOGGING_AND_PROFILING_ENABLED>::Initialize(); |
| ScavengingVisitor<IGNORE_MARKS, LOGGING_AND_PROFILING_ENABLED>::Initialize(); |
| } |
| |
| |
| void Heap::SelectScavengingVisitorsTable() { |
| bool logging_and_profiling = |
| isolate()->logger()->is_logging() || |
| CpuProfiler::is_profiling(isolate()) || |
| (isolate()->heap_profiler() != NULL && |
| isolate()->heap_profiler()->is_profiling()); |
| |
| if (!incremental_marking()->IsMarking()) { |
| if (!logging_and_profiling) { |
| scavenging_visitors_table_.CopyFrom( |
| ScavengingVisitor<IGNORE_MARKS, |
| LOGGING_AND_PROFILING_DISABLED>::GetTable()); |
| } else { |
| scavenging_visitors_table_.CopyFrom( |
| ScavengingVisitor<IGNORE_MARKS, |
| LOGGING_AND_PROFILING_ENABLED>::GetTable()); |
| } |
| } else { |
| if (!logging_and_profiling) { |
| scavenging_visitors_table_.CopyFrom( |
| ScavengingVisitor<TRANSFER_MARKS, |
| LOGGING_AND_PROFILING_DISABLED>::GetTable()); |
| } else { |
| scavenging_visitors_table_.CopyFrom( |
| ScavengingVisitor<TRANSFER_MARKS, |
| LOGGING_AND_PROFILING_ENABLED>::GetTable()); |
| } |
| |
| if (incremental_marking()->IsCompacting()) { |
| // When compacting forbid short-circuiting of cons-strings. |
| // Scavenging code relies on the fact that new space object |
| // can't be evacuated into evacuation candidate but |
| // short-circuiting violates this assumption. |
| scavenging_visitors_table_.Register( |
| StaticVisitorBase::kVisitShortcutCandidate, |
| scavenging_visitors_table_.GetVisitorById( |
| StaticVisitorBase::kVisitConsString)); |
| } |
| } |
| } |
| |
| |
| void Heap::ScavengeObjectSlow(HeapObject** p, HeapObject* object) { |
| SLOW_ASSERT(HEAP->InFromSpace(object)); |
| MapWord first_word = object->map_word(); |
| SLOW_ASSERT(!first_word.IsForwardingAddress()); |
| Map* map = first_word.ToMap(); |
| map->GetHeap()->DoScavengeObject(map, p, object); |
| } |
| |
| |
| 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); |
| reinterpret_cast<Map*>(result)->set_bit_field3( |
| Map::LastAddedBits::encode(Map::kNoneAdded)); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateMap(InstanceType instance_type, |
| int instance_size, |
| ElementsKind elements_kind) { |
| Object* result; |
| MaybeObject* maybe_result = AllocateRawMap(); |
| if (!maybe_result->To(&result)) return maybe_result; |
| |
| Map* map = reinterpret_cast<Map*>(result); |
| map->set_map_no_write_barrier(meta_map()); |
| map->set_instance_type(instance_type); |
| map->set_visitor_id( |
| StaticVisitorBase::GetVisitorId(instance_type, instance_size)); |
| map->set_prototype(null_value(), SKIP_WRITE_BARRIER); |
| map->set_constructor(null_value(), SKIP_WRITE_BARRIER); |
| map->set_instance_size(instance_size); |
| map->set_inobject_properties(0); |
| map->set_pre_allocated_property_fields(0); |
| map->set_code_cache(empty_fixed_array(), SKIP_WRITE_BARRIER); |
| map->init_back_pointer(undefined_value()); |
| map->set_unused_property_fields(0); |
| map->set_bit_field(0); |
| map->set_bit_field2(1 << Map::kIsExtensible); |
| map->set_bit_field3(Map::LastAddedBits::encode(Map::kNoneAdded)); |
| map->set_elements_kind(elements_kind); |
| |
| // 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() { |
| CodeCache* code_cache; |
| { MaybeObject* maybe_code_cache = AllocateStruct(CODE_CACHE_TYPE); |
| if (!maybe_code_cache->To(&code_cache)) return maybe_code_cache; |
| } |
| code_cache->set_default_cache(empty_fixed_array(), SKIP_WRITE_BARRIER); |
| code_cache->set_normal_type_cache(undefined_value(), SKIP_WRITE_BARRIER); |
| return code_cache; |
| } |
| |
| |
| MaybeObject* Heap::AllocatePolymorphicCodeCache() { |
| return AllocateStruct(POLYMORPHIC_CODE_CACHE_TYPE); |
| } |
| |
| |
| MaybeObject* Heap::AllocateAccessorPair() { |
| AccessorPair* accessors; |
| { MaybeObject* maybe_accessors = AllocateStruct(ACCESSOR_PAIR_TYPE); |
| if (!maybe_accessors->To(&accessors)) return maybe_accessors; |
| } |
| accessors->set_getter(the_hole_value(), SKIP_WRITE_BARRIER); |
| accessors->set_setter(the_hole_value(), SKIP_WRITE_BARRIER); |
| return accessors; |
| } |
| |
| |
| MaybeObject* Heap::AllocateTypeFeedbackInfo() { |
| TypeFeedbackInfo* info; |
| { MaybeObject* maybe_info = AllocateStruct(TYPE_FEEDBACK_INFO_TYPE); |
| if (!maybe_info->To(&info)) return maybe_info; |
| } |
| info->set_ic_total_count(0); |
| info->set_ic_with_type_info_count(0); |
| info->set_type_feedback_cells(TypeFeedbackCells::cast(empty_fixed_array()), |
| SKIP_WRITE_BARRIER); |
| return info; |
| } |
| |
| |
| MaybeObject* Heap::AllocateAliasedArgumentsEntry(int aliased_context_slot) { |
| AliasedArgumentsEntry* entry; |
| { MaybeObject* maybe_entry = AllocateStruct(ALIASED_ARGUMENTS_ENTRY_TYPE); |
| if (!maybe_entry->To(&entry)) return maybe_entry; |
| } |
| entry->set_aliased_context_slot(aliased_context_slot); |
| return entry; |
| } |
| |
| |
| 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_POINTER_SPACE); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_null_value(Oddball::cast(obj)); |
| Oddball::cast(obj)->set_kind(Oddball::kNull); |
| |
| { MaybeObject* maybe_obj = Allocate(oddball_map(), OLD_POINTER_SPACE); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_undefined_value(Oddball::cast(obj)); |
| Oddball::cast(obj)->set_kind(Oddball::kUndefined); |
| ASSERT(!InNewSpace(undefined_value())); |
| |
| // 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_code_cache(empty_fixed_array()); |
| meta_map()->init_back_pointer(undefined_value()); |
| |
| fixed_array_map()->set_code_cache(empty_fixed_array()); |
| fixed_array_map()->init_back_pointer(undefined_value()); |
| |
| oddball_map()->set_code_cache(empty_fixed_array()); |
| oddball_map()->init_back_pointer(undefined_value()); |
| |
| // 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(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_scope_info_map(Map::cast(obj)); |
| |
| { 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(FOREIGN_TYPE, Foreign::kSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_foreign_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(FIXED_DOUBLE_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_fixed_double_array_map(Map::cast(obj)); |
| |
| { 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 = |
| AllocateMap(FREE_SPACE_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_free_space_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(EXTERNAL_PIXEL_ARRAY_TYPE, ExternalArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_external_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(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_non_strict_arguments_elements_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateMap(EXTERNAL_DOUBLE_ARRAY_TYPE, |
| ExternalArray::kAlignedSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_external_double_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_function_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; |
| } |
| set_with_context_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_block_context_map(Map::cast(obj)); |
| |
| { MaybeObject* maybe_obj = |
| AllocateMap(FIXED_ARRAY_TYPE, kVariableSizeSentinel); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_module_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(!InNewSpace(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::kNonCodeObjectAreaSize); |
| 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_no_write_barrier(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::kMaxNonCodeHeapObjectSize); |
| 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_no_write_barrier(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_no_write_barrier( |
| global_property_cell_map()); |
| JSGlobalPropertyCell::cast(result)->set_value(value); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::CreateOddball(const char* to_string, |
| Object* to_number, |
| byte kind) { |
| Object* result; |
| { MaybeObject* maybe_result = Allocate(oddball_map(), OLD_POINTER_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| return Oddball::cast(result)->Initialize(to_string, to_number, kind); |
| } |
| |
| |
| bool Heap::CreateApiObjects() { |
| Object* obj; |
| |
| { MaybeObject* maybe_obj = AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| // Don't use Smi-only elements optimizations for objects with the neander |
| // map. There are too many cases where element values are set directly with a |
| // bottleneck to trap the Smi-only -> fast elements transition, and there |
| // appears to be no benefit for optimize this case. |
| Map* new_neander_map = Map::cast(obj); |
| new_neander_map->set_elements_kind(TERMINAL_FAST_ELEMENTS_KIND); |
| set_neander_map(new_neander_map); |
| |
| { MaybeObject* maybe_obj = 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::CreateJSEntryStub() { |
| JSEntryStub stub; |
| set_js_entry_code(*stub.GetCode()); |
| } |
| |
| |
| void Heap::CreateJSConstructEntryStub() { |
| JSConstructEntryStub stub; |
| set_js_construct_entry_code(*stub.GetCode()); |
| } |
| |
| |
| void Heap::CreateFixedStubs() { |
| // Here we create roots for fixed stubs. They are needed at GC |
| // for cooking and uncooking (check out frames.cc). |
| // The eliminates the need for doing dictionary lookup in the |
| // stub cache for these stubs. |
| HandleScope scope; |
| // gcc-4.4 has problem generating correct code of following snippet: |
| // { JSEntryStub stub; |
| // js_entry_code_ = *stub.GetCode(); |
| // } |
| // { JSConstructEntryStub stub; |
| // js_construct_entry_code_ = *stub.GetCode(); |
| // } |
| // To workaround the problem, make separate functions without inlining. |
| Heap::CreateJSEntryStub(); |
| Heap::CreateJSConstructEntryStub(); |
| |
| // Create stubs that should be there, so we don't unexpectedly have to |
| // create them if we need them during the creation of another stub. |
| // Stub creation mixes raw pointers and handles in an unsafe manner so |
| // we cannot create stubs while we are creating stubs. |
| CodeStub::GenerateStubsAheadOfTime(); |
| } |
| |
| |
| 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(HeapNumber::cast(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(HeapNumber::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateHeapNumber(V8_INFINITY, TENURED); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_infinity_value(HeapNumber::cast(obj)); |
| |
| // The hole has not been created yet, but we want to put something |
| // predictable in the gaps in the symbol table, so lets make that Smi zero. |
| set_the_hole_value(reinterpret_cast<Oddball*>(Smi::FromInt(0))); |
| |
| // 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; |
| |
| // Finish initializing oddballs after creating symboltable. |
| { MaybeObject* maybe_obj = |
| undefined_value()->Initialize("undefined", |
| nan_value(), |
| Oddball::kUndefined); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| |
| // Initialize the null_value. |
| { MaybeObject* maybe_obj = |
| null_value()->Initialize("null", Smi::FromInt(0), Oddball::kNull); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| |
| { MaybeObject* maybe_obj = CreateOddball("true", |
| Smi::FromInt(1), |
| Oddball::kTrue); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_true_value(Oddball::cast(obj)); |
| |
| { MaybeObject* maybe_obj = CreateOddball("false", |
| Smi::FromInt(0), |
| Oddball::kFalse); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_false_value(Oddball::cast(obj)); |
| |
| { MaybeObject* maybe_obj = CreateOddball("hole", |
| Smi::FromInt(-1), |
| Oddball::kTheHole); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_the_hole_value(Oddball::cast(obj)); |
| |
| { MaybeObject* maybe_obj = CreateOddball("arguments_marker", |
| Smi::FromInt(-4), |
| Oddball::kArgumentMarker); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_arguments_marker(Oddball::cast(obj)); |
| |
| { MaybeObject* maybe_obj = CreateOddball("no_interceptor_result_sentinel", |
| Smi::FromInt(-2), |
| Oddball::kOther); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_no_interceptor_result_sentinel(obj); |
| |
| { MaybeObject* maybe_obj = CreateOddball("termination_exception", |
| Smi::FromInt(-3), |
| Oddball::kOther); |
| 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 foreign for __proto__. |
| { MaybeObject* maybe_obj = |
| AllocateForeign((Address) &Accessors::ObjectPrototype); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_prototype_accessors(Foreign::cast(obj)); |
| |
| // Allocate the code_stubs dictionary. The initial size is set to avoid |
| // expanding the dictionary during bootstrapping. |
| { MaybeObject* maybe_obj = UnseededNumberDictionary::Allocate(128); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_code_stubs(UnseededNumberDictionary::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 = UnseededNumberDictionary::Allocate(64); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_non_monomorphic_cache(UnseededNumberDictionary::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocatePolymorphicCodeCache(); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_polymorphic_code_cache(PolymorphicCodeCache::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(this, |
| obj); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_intrinsic_function_names(StringDictionary::cast(obj)); |
| |
| { MaybeObject* maybe_obj = AllocateInitialNumberStringCache(); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_number_string_cache(FixedArray::cast(obj)); |
| |
| // 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 string split. |
| { MaybeObject* maybe_obj = |
| AllocateFixedArray(StringSplitCache::kStringSplitCacheSize, TENURED); |
| if (!maybe_obj->ToObject(&obj)) return false; |
| } |
| set_string_split_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. |
| isolate_->keyed_lookup_cache()->Clear(); |
| |
| // Initialize context slot cache. |
| isolate_->context_slot_cache()->Clear(); |
| |
| // Initialize descriptor cache. |
| isolate_->descriptor_lookup_cache()->Clear(); |
| |
| // Initialize compilation cache. |
| isolate_->compilation_cache()->Clear(); |
| |
| return true; |
| } |
| |
| |
| Object* StringSplitCache::Lookup( |
| FixedArray* cache, String* string, String* pattern) { |
| if (!string->IsSymbol() || !pattern->IsSymbol()) return Smi::FromInt(0); |
| uint32_t hash = string->Hash(); |
| uint32_t index = ((hash & (kStringSplitCacheSize - 1)) & |
| ~(kArrayEntriesPerCacheEntry - 1)); |
| if (cache->get(index + kStringOffset) == string && |
| cache->get(index + kPatternOffset) == pattern) { |
| return cache->get(index + kArrayOffset); |
| } |
| index = ((index + kArrayEntriesPerCacheEntry) & (kStringSplitCacheSize - 1)); |
| if (cache->get(index + kStringOffset) == string && |
| cache->get(index + kPatternOffset) == pattern) { |
| return cache->get(index + kArrayOffset); |
| } |
| return Smi::FromInt(0); |
| } |
| |
| |
| void StringSplitCache::Enter(Heap* heap, |
| FixedArray* cache, |
| String* string, |
| String* pattern, |
| FixedArray* array) { |
| if (!string->IsSymbol() || !pattern->IsSymbol()) return; |
| uint32_t hash = string->Hash(); |
| uint32_t index = ((hash & (kStringSplitCacheSize - 1)) & |
| ~(kArrayEntriesPerCacheEntry - 1)); |
| if (cache->get(index + kStringOffset) == Smi::FromInt(0)) { |
| cache->set(index + kStringOffset, string); |
| cache->set(index + kPatternOffset, pattern); |
| cache->set(index + kArrayOffset, array); |
| } else { |
| uint32_t index2 = |
| ((index + kArrayEntriesPerCacheEntry) & (kStringSplitCacheSize - 1)); |
| if (cache->get(index2 + kStringOffset) == Smi::FromInt(0)) { |
| cache->set(index2 + kStringOffset, string); |
| cache->set(index2 + kPatternOffset, pattern); |
| cache->set(index2 + kArrayOffset, array); |
| } else { |
| cache->set(index2 + kStringOffset, Smi::FromInt(0)); |
| cache->set(index2 + kPatternOffset, Smi::FromInt(0)); |
| cache->set(index2 + kArrayOffset, Smi::FromInt(0)); |
| cache->set(index + kStringOffset, string); |
| cache->set(index + kPatternOffset, pattern); |
| cache->set(index + kArrayOffset, array); |
| } |
| } |
| if (array->length() < 100) { // Limit how many new symbols we want to make. |
| for (int i = 0; i < array->length(); i++) { |
| String* str = String::cast(array->get(i)); |
| Object* symbol; |
| MaybeObject* maybe_symbol = heap->LookupSymbol(str); |
| if (maybe_symbol->ToObject(&symbol)) { |
| array->set(i, symbol); |
| } |
| } |
| } |
| array->set_map_no_write_barrier(heap->fixed_cow_array_map()); |
| } |
| |
| |
| void StringSplitCache::Clear(FixedArray* cache) { |
| for (int i = 0; i < kStringSplitCacheSize; i++) { |
| cache->set(i, Smi::FromInt(0)); |
| } |
| } |
| |
| |
| MaybeObject* Heap::AllocateInitialNumberStringCache() { |
| MaybeObject* maybe_obj = |
| AllocateFixedArray(kInitialNumberStringCacheSize * 2, TENURED); |
| return maybe_obj; |
| } |
| |
| |
| int Heap::FullSizeNumberStringCacheLength() { |
| // Compute the size of the number string cache based on the max newspace size. |
| // The number string cache has a minimum size based on twice the initial cache |
| // size to ensure that it is bigger after being made 'full size'. |
| int number_string_cache_size = max_semispace_size_ / 512; |
| number_string_cache_size = Max(kInitialNumberStringCacheSize * 2, |
| Min(0x4000, number_string_cache_size)); |
| // There is a string and a number per entry so the length is twice the number |
| // of entries. |
| return number_string_cache_size * 2; |
| } |
| |
| |
| void Heap::AllocateFullSizeNumberStringCache() { |
| // The idea is to have a small number string cache in the snapshot to keep |
| // boot-time memory usage down. If we expand the number string cache already |
| // while creating the snapshot then that didn't work out. |
| ASSERT(!Serializer::enabled() || FLAG_extra_code != NULL); |
| MaybeObject* maybe_obj = |
| AllocateFixedArray(FullSizeNumberStringCacheLength(), TENURED); |
| Object* new_cache; |
| if (maybe_obj->ToObject(&new_cache)) { |
| // We don't bother to repopulate the cache with entries from the old cache. |
| // It will be repopulated soon enough with new strings. |
| set_number_string_cache(FixedArray::cast(new_cache)); |
| } |
| // If allocation fails then we just return without doing anything. It is only |
| // a cache, so best effort is OK here. |
| } |
| |
| |
| 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(this, 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; |
| } else { |
| hash = double_get_hash(number->Number()) & mask; |
| } |
| if (number_string_cache()->get(hash * 2) != undefined_value() && |
| number_string_cache()->length() != FullSizeNumberStringCacheLength()) { |
| // The first time we have a hash collision, we move to the full sized |
| // number string cache. |
| AllocateFullSizeNumberStringCache(); |
| return; |
| } |
| 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) { |
| isolate_->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; |
| } |
| |
| |
| MaybeObject* Heap::Uint32ToString(uint32_t value, |
| bool check_number_string_cache) { |
| Object* number; |
| MaybeObject* maybe = NumberFromUint32(value); |
| if (!maybe->To<Object>(&number)) return maybe; |
| return NumberToString(number, check_number_string_cache); |
| } |
| |
| |
| 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; |
| case kExternalDoubleArray: |
| return kExternalDoubleArrayMapRootIndex; |
| case kExternalPixelArray: |
| return kExternalPixelArrayMapRootIndex; |
| 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::AllocateForeign(Address address, PretenureFlag pretenure) { |
| // Statically ensure that it is safe to allocate foreigns in paged spaces. |
| STATIC_ASSERT(Foreign::kSize <= Page::kMaxNonCodeHeapObjectSize); |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| Foreign* result; |
| MaybeObject* maybe_result = Allocate(foreign_map(), space); |
| if (!maybe_result->To(&result)) return maybe_result; |
| result->set_foreign_address(address); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateSharedFunctionInfo(Object* name) { |
| SharedFunctionInfo* share; |
| MaybeObject* maybe = Allocate(shared_function_info_map(), OLD_POINTER_SPACE); |
| if (!maybe->To<SharedFunctionInfo>(&share)) return maybe; |
| |
| // Set pointer fields. |
| share->set_name(name); |
| Code* illegal = isolate_->builtins()->builtin(Builtins::kIllegal); |
| share->set_code(illegal); |
| share->ClearOptimizedCodeMap(); |
| share->set_scope_info(ScopeInfo::Empty()); |
| Code* construct_stub = |
| isolate_->builtins()->builtin(Builtins::kJSConstructStubGeneric); |
| share->set_construct_stub(construct_stub); |
| share->set_instance_class_name(Object_symbol()); |
| share->set_function_data(undefined_value(), SKIP_WRITE_BARRIER); |
| share->set_script(undefined_value(), SKIP_WRITE_BARRIER); |
| share->set_debug_info(undefined_value(), SKIP_WRITE_BARRIER); |
| share->set_inferred_name(empty_string(), SKIP_WRITE_BARRIER); |
| share->set_initial_map(undefined_value(), SKIP_WRITE_BARRIER); |
| share->set_this_property_assignments(undefined_value(), SKIP_WRITE_BARRIER); |
| share->set_ast_node_count(0); |
| share->set_stress_deopt_counter(FLAG_deopt_every_n_times); |
| share->set_counters(0); |
| |
| // Set integer fields (smi or int, depending on the architecture). |
| share->set_length(0); |
| share->set_formal_parameter_count(0); |
| share->set_expected_nof_properties(0); |
| share->set_num_literals(0); |
| share->set_start_position_and_type(0); |
| share->set_end_position(0); |
| share->set_function_token_position(0); |
| // All compiler hints default to false or 0. |
| share->set_compiler_hints(0); |
| share->set_this_property_assignments_count(0); |
| share->set_opt_count(0); |
| |
| return share; |
| } |
| |
| |
| 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(), SKIP_WRITE_BARRIER); |
| message->initialize_elements(); |
| message->set_elements(Heap::empty_fixed_array(), SKIP_WRITE_BARRIER); |
| 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( |
| Heap* heap, |
| 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(this, 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) { |
| isolate()->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) { |
| isolate_->counters()->string_add_runtime_ext_to_ascii()->Increment(); |
| } |
| } |
| |
| // If the resulting string is small make a flat string. |
| if (length < ConsString::kMinLength) { |
| // Note that neither of the two inputs can be a slice because: |
| STATIC_ASSERT(ConsString::kMinLength <= SlicedString::kMinLength); |
| 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)->GetChars(); |
| } 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)->GetChars(); |
| } 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); |
| isolate_->counters()->string_add_runtime_ext_to_ascii()->Increment(); |
| 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 <= 0) { |
| return empty_string(); |
| } else if (length == 1) { |
| return 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(this, c1, c2); |
| } |
| |
| // Make an attempt to flatten the buffer to reduce access time. |
| buffer = buffer->TryFlattenGetString(); |
| |
| if (!FLAG_string_slices || |
| !buffer->IsFlat() || |
| length < SlicedString::kMinLength || |
| pretenure == TENURED) { |
| Object* result; |
| // WriteToFlat takes care of the case when an indirect string has a |
| // different encoding from its underlying string. These encodings may |
| // differ because of externalization. |
| bool is_ascii = buffer->IsAsciiRepresentation(); |
| { MaybeObject* maybe_result = is_ascii |
| ? 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 (is_ascii) { |
| 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; |
| } |
| |
| ASSERT(buffer->IsFlat()); |
| #if DEBUG |
| if (FLAG_verify_heap) { |
| buffer->StringVerify(); |
| } |
| #endif |
| |
| Object* result; |
| // When slicing an indirect string we use its encoding for a newly created |
| // slice and don't check the encoding of the underlying string. This is safe |
| // even if the encodings are different because of externalization. If an |
| // indirect ASCII string is pointing to a two-byte string, the two-byte char |
| // codes of the underlying string must still fit into ASCII (because |
| // externalization must not change char codes). |
| { Map* map = buffer->IsAsciiRepresentation() |
| ? sliced_ascii_string_map() |
| : sliced_string_map(); |
| MaybeObject* maybe_result = Allocate(map, NEW_SPACE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| AssertNoAllocation no_gc; |
| SlicedString* sliced_string = SlicedString::cast(result); |
| sliced_string->set_length(length); |
| sliced_string->set_hash_field(String::kEmptyHashField); |
| if (buffer->IsConsString()) { |
| ConsString* cons = ConsString::cast(buffer); |
| ASSERT(cons->second()->length() == 0); |
| sliced_string->set_parent(cons->first()); |
| sliced_string->set_offset(start); |
| } else if (buffer->IsSlicedString()) { |
| // Prevent nesting sliced strings. |
| SlicedString* parent_slice = SlicedString::cast(buffer); |
| sliced_string->set_parent(parent_slice->parent()); |
| sliced_string->set_offset(start + parent_slice->offset()); |
| } else { |
| sliced_string->set_parent(buffer); |
| sliced_string->set_offset(start); |
| } |
| ASSERT(sliced_string->parent()->IsSeqString() || |
| sliced_string->parent()->IsExternalString()); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateExternalStringFromAscii( |
| const ExternalAsciiString::Resource* resource) { |
| size_t length = resource->length(); |
| if (length > static_cast<size_t>(String::kMaxLength)) { |
| isolate()->context()->mark_out_of_memory(); |
| return Failure::OutOfMemoryException(); |
| } |
| |
| ASSERT(String::IsAscii(resource->data(), static_cast<int>(length))); |
| |
| 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( |
| const ExternalTwoByteString::Resource* resource) { |
| size_t length = resource->length(); |
| if (length > static_cast<size_t>(String::kMaxLength)) { |
| isolate()->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 ? |
| external_string_with_ascii_data_map() : 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 = single_character_string_cache()->get(code); |
| if (value != 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; |
| single_character_string_cache()->set(code, result); |
| return result; |
| } |
| |
| Object* result; |
| { MaybeObject* maybe_result = 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 <= Page::kMaxNonCodeHeapObjectSize) |
| ? old_data_space_->AllocateRaw(size) |
| : lo_space_->AllocateRaw(size, NOT_EXECUTABLE); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| reinterpret_cast<ByteArray*>(result)->set_map_no_write_barrier( |
| 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 > Page::kMaxNonCodeHeapObjectSize) ? 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_no_write_barrier( |
| 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_no_write_barrier(one_pointer_filler_map()); |
| } else if (size == 2 * kPointerSize) { |
| filler->set_map_no_write_barrier(two_pointer_filler_map()); |
| } else { |
| filler->set_map_no_write_barrier(free_space_map()); |
| FreeSpace::cast(filler)->set_size(size); |
| } |
| } |
| |
| |
| 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_no_write_barrier( |
| 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, |
| bool immovable) { |
| // Allocate ByteArray before the Code object, so that we do not risk |
| // leaving uninitialized Code object (and breaking the heap). |
| ByteArray* reloc_info; |
| MaybeObject* maybe_reloc_info = AllocateByteArray(desc.reloc_size, TENURED); |
| if (!maybe_reloc_info->To(&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; |
| // Large code objects and code objects which should stay at a fixed address |
| // are allocated in large object space. |
| if (obj_size > code_space()->AreaSize() || immovable) { |
| maybe_result = lo_space_->AllocateRaw(obj_size, EXECUTABLE); |
| } 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_no_write_barrier(code_map()); |
| Code* code = Code::cast(result); |
| ASSERT(!isolate_->code_range()->exists() || |
| isolate_->code_range()->contains(code->address())); |
| code->set_instruction_size(desc.instr_size); |
| code->set_relocation_info(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(), SKIP_WRITE_BARRIER); |
| code->set_type_feedback_info(undefined_value(), SKIP_WRITE_BARRIER); |
| code->set_handler_table(empty_fixed_array(), SKIP_WRITE_BARRIER); |
| code->set_gc_metadata(Smi::FromInt(0)); |
| code->set_ic_age(global_ic_age_); |
| // 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 |
| if (FLAG_verify_heap) { |
| 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 > code_space()->AreaSize()) { |
| maybe_result = lo_space_->AllocateRaw(obj_size, EXECUTABLE); |
| } 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(!isolate_->code_range()->exists() || |
| isolate_->code_range()->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 > code_space()->AreaSize()) { |
| maybe_result = lo_space_->AllocateRaw(new_obj_size, EXECUTABLE); |
| } 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(!isolate_->code_range()->exists() || |
| isolate_->code_range()->contains(code->address())); |
| new_code->Relocate(new_addr - old_addr); |
| |
| #ifdef DEBUG |
| if (FLAG_verify_heap) { |
| 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; |
| } |
| // No need for write barrier since object is white and map is in old space. |
| HeapObject::cast(result)->set_map_no_write_barrier(map); |
| return result; |
| } |
| |
| |
| void 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_or_bindings(empty_fixed_array()); |
| function->set_next_function_link(undefined_value()); |
| } |
| |
| |
| 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(); |
| |
| // Each function prototype gets a copy of the object function map. |
| // This avoid unwanted sharing of maps between prototypes of different |
| // constructors. |
| Map* new_map; |
| ASSERT(object_function->has_initial_map()); |
| MaybeObject* maybe_map = |
| object_function->initial_map()->Copy(DescriptorArray::MAY_BE_SHARED); |
| if (!maybe_map->To(&new_map)) return maybe_map; |
| |
| Object* prototype; |
| MaybeObject* maybe_prototype = AllocateJSObjectFromMap(new_map); |
| if (!maybe_prototype->ToObject(&prototype)) return maybe_prototype; |
| |
| // When creating the prototype for the function we must set its |
| // constructor to the function. |
| MaybeObject* maybe_failure = |
| JSObject::cast(prototype)->SetLocalPropertyIgnoreAttributes( |
| constructor_symbol(), function, DONT_ENUM); |
| if (maybe_failure->IsFailure()) return maybe_failure; |
| |
| 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; |
| } |
| InitializeFunction(JSFunction::cast(result), shared, prototype); |
| return result; |
| } |
| |
| |
| 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. |
| |
| JSObject* boilerplate; |
| int arguments_object_size; |
| bool strict_mode_callee = callee->IsJSFunction() && |
| !JSFunction::cast(callee)->shared()->is_classic_mode(); |
| if (strict_mode_callee) { |
| boilerplate = |
| isolate()->context()->global_context()-> |
| strict_mode_arguments_boilerplate(); |
| arguments_object_size = kArgumentsObjectSizeStrict; |
| } else { |
| boilerplate = |
| isolate()->context()->global_context()->arguments_boilerplate(); |
| arguments_object_size = kArgumentsObjectSize; |
| } |
| |
| // This calls Copy directly rather than using Heap::AllocateRaw so we |
| // duplicate the check here. |
| ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| |
| // Check that the size of the boilerplate matches our |
| // expectations. The ArgumentsAccessStub::GenerateNewObject relies |
| // on the size being a known constant. |
| ASSERT(arguments_object_size == boilerplate->map()->instance_size()); |
| |
| // Do the allocation. |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateRaw(arguments_object_size, 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(), |
| JSObject::kHeaderSize); |
| |
| // Set the length property. |
| JSObject::cast(result)->InObjectPropertyAtPut(kArgumentsLengthIndex, |
| Smi::FromInt(length), |
| SKIP_WRITE_BARRIER); |
| // Set the callee property for non-strict mode arguments object only. |
| if (!strict_mode_callee) { |
| JSObject::cast(result)->InObjectPropertyAtPut(kArgumentsCalleeIndex, |
| callee); |
| } |
| |
| // Check the state of the object |
| ASSERT(JSObject::cast(result)->HasFastProperties()); |
| ASSERT(JSObject::cast(result)->HasFastObjectElements()); |
| |
| 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(); |
| Map* map; |
| MaybeObject* maybe_map = AllocateMap(JS_OBJECT_TYPE, instance_size); |
| if (!maybe_map->To(&map)) return maybe_map; |
| |
| // Fetch or allocate prototype. |
| Object* prototype; |
| if (fun->has_instance_prototype()) { |
| prototype = fun->instance_prototype(); |
| } else { |
| MaybeObject* maybe_prototype = AllocateFunctionPrototype(fun); |
| if (!maybe_prototype->To(&prototype)) return maybe_prototype; |
| } |
| map->set_inobject_properties(in_object_properties); |
| map->set_unused_property_fields(in_object_properties); |
| map->set_prototype(prototype); |
| ASSERT(map->has_fast_object_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 { |
| DescriptorArray* descriptors; |
| MaybeObject* maybe_descriptors = |
| DescriptorArray::Allocate(count, DescriptorArray::MAY_BE_SHARED); |
| if (!maybe_descriptors->To(&descriptors)) return maybe_descriptors; |
| |
| DescriptorArray::WhitenessWitness witness(descriptors); |
| for (int i = 0; i < count; i++) { |
| String* name = fun->shared()->GetThisPropertyAssignmentName(i); |
| ASSERT(name->IsSymbol()); |
| FieldDescriptor field(name, i, NONE, i + 1); |
| descriptors->Set(i, &field, witness); |
| } |
| descriptors->Sort(witness); |
| |
| // 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->InitializeDescriptors(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 (e.g. Smi::FromInt(0)) and the elements initialized to a |
| // fixed array (e.g. Heap::empty_fixed_array()). Currently, the object |
| // verification code has to cope with (temporarily) invalid objects. See |
| // for example, JSArray::JSArrayVerify). |
| 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. |
| // Pre-allocated fields need to be initialized with undefined_value as well |
| // so that object accesses before the constructor completes (e.g. in the |
| // debugger) will not cause a crash. |
| 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, Heap::undefined_value(), 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() > Page::kMaxNonCodeHeapObjectSize) 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)->HasFastSmiOrObjectElements()); |
| 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::AllocateJSModule(Context* context, ScopeInfo* scope_info) { |
| // Allocate a fresh map. Modules do not have a prototype. |
| Map* map; |
| MaybeObject* maybe_map = AllocateMap(JS_MODULE_TYPE, JSModule::kSize); |
| if (!maybe_map->To(&map)) return maybe_map; |
| // Allocate the object based on the map. |
| JSModule* module; |
| MaybeObject* maybe_module = AllocateJSObjectFromMap(map, TENURED); |
| if (!maybe_module->To(&module)) return maybe_module; |
| module->set_context(context); |
| module->set_scope_info(scope_info); |
| return module; |
| } |
| |
| |
| MaybeObject* Heap::AllocateJSArrayAndStorage( |
| ElementsKind elements_kind, |
| int length, |
| int capacity, |
| ArrayStorageAllocationMode mode, |
| PretenureFlag pretenure) { |
| ASSERT(capacity >= length); |
| if (length != 0 && mode == INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE) { |
| elements_kind = GetHoleyElementsKind(elements_kind); |
| } |
| MaybeObject* maybe_array = AllocateJSArray(elements_kind, pretenure); |
| JSArray* array; |
| if (!maybe_array->To(&array)) return maybe_array; |
| |
| if (capacity == 0) { |
| array->set_length(Smi::FromInt(0)); |
| array->set_elements(empty_fixed_array()); |
| return array; |
| } |
| |
| FixedArrayBase* elms; |
| MaybeObject* maybe_elms = NULL; |
| if (elements_kind == FAST_DOUBLE_ELEMENTS) { |
| if (mode == DONT_INITIALIZE_ARRAY_ELEMENTS) { |
| maybe_elms = AllocateUninitializedFixedDoubleArray(capacity); |
| } else { |
| ASSERT(mode == INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE); |
| maybe_elms = AllocateFixedDoubleArrayWithHoles(capacity); |
| } |
| } else { |
| ASSERT(IsFastSmiOrObjectElementsKind(elements_kind)); |
| if (mode == DONT_INITIALIZE_ARRAY_ELEMENTS) { |
| maybe_elms = AllocateUninitializedFixedArray(capacity); |
| } else { |
| ASSERT(mode == INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE); |
| maybe_elms = AllocateFixedArrayWithHoles(capacity); |
| } |
| } |
| if (!maybe_elms->To(&elms)) return maybe_elms; |
| |
| array->set_elements(elms); |
| array->set_length(Smi::FromInt(length)); |
| return array; |
| } |
| |
| |
| MaybeObject* Heap::AllocateJSArrayWithElements( |
| FixedArrayBase* elements, |
| ElementsKind elements_kind, |
| PretenureFlag pretenure) { |
| MaybeObject* maybe_array = AllocateJSArray(elements_kind, pretenure); |
| JSArray* array; |
| if (!maybe_array->To(&array)) return maybe_array; |
| |
| array->set_elements(elements); |
| array->set_length(Smi::FromInt(elements->length())); |
| array->ValidateElements(); |
| return array; |
| } |
| |
| |
| MaybeObject* Heap::AllocateJSProxy(Object* handler, Object* prototype) { |
| // Allocate map. |
| // TODO(rossberg): Once we optimize proxies, think about a scheme to share |
| // maps. Will probably depend on the identity of the handler object, too. |
| Map* map; |
| MaybeObject* maybe_map_obj = AllocateMap(JS_PROXY_TYPE, JSProxy::kSize); |
| if (!maybe_map_obj->To<Map>(&map)) return maybe_map_obj; |
| map->set_prototype(prototype); |
| |
| // Allocate the proxy object. |
| JSProxy* result; |
| MaybeObject* maybe_result = Allocate(map, NEW_SPACE); |
| if (!maybe_result->To<JSProxy>(&result)) return maybe_result; |
| result->InitializeBody(map->instance_size(), Smi::FromInt(0)); |
| result->set_handler(handler); |
| result->set_hash(undefined_value(), SKIP_WRITE_BARRIER); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateJSFunctionProxy(Object* handler, |
| Object* call_trap, |
| Object* construct_trap, |
| Object* prototype) { |
| // Allocate map. |
| // TODO(rossberg): Once we optimize proxies, think about a scheme to share |
| // maps. Will probably depend on the identity of the handler object, too. |
| Map* map; |
| MaybeObject* maybe_map_obj = |
| AllocateMap(JS_FUNCTION_PROXY_TYPE, JSFunctionProxy::kSize); |
| if (!maybe_map_obj->To<Map>(&map)) return maybe_map_obj; |
| map->set_prototype(prototype); |
| |
| // Allocate the proxy object. |
| JSFunctionProxy* result; |
| MaybeObject* maybe_result = Allocate(map, NEW_SPACE); |
| if (!maybe_result->To<JSFunctionProxy>(&result)) return maybe_result; |
| result->InitializeBody(map->instance_size(), Smi::FromInt(0)); |
| result->set_handler(handler); |
| result->set_hash(undefined_value(), SKIP_WRITE_BARRIER); |
| result->set_call_trap(call_trap); |
| result->set_construct_trap(construct_trap); |
| 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. |
| StringDictionary* dictionary; |
| MaybeObject* maybe_dictionary = |
| StringDictionary::Allocate( |
| map->NumberOfDescribedProperties() * 2 + initial_size); |
| if (!maybe_dictionary->To(&dictionary)) return maybe_dictionary; |
| |
| // 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 = AllocateJSGlobalPropertyCell(value); |
| if (!maybe_value->ToObject(&value)) return maybe_value; |
| |
| MaybeObject* maybe_added = dictionary->Add(descs->GetKey(i), value, d); |
| if (!maybe_added->To(&dictionary)) return maybe_added; |
| } |
| |
| // Allocate the global object and initialize it with the backing store. |
| JSObject* global; |
| MaybeObject* maybe_global = Allocate(map, OLD_POINTER_SPACE); |
| if (!maybe_global->To(&global)) return maybe_global; |
| |
| InitializeJSObjectFromMap(global, dictionary, map); |
| |
| // Create a new map for the global object. |
| Map* new_map; |
| MaybeObject* maybe_map = map->CopyDropDescriptors(); |
| if (!maybe_map->To(&new_map)) return maybe_map; |
| |
| // Set up the global object as a normalized object. |
| global->set_map(new_map); |
| 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. |
| SLOW_ASSERT(!source->IsJSFunction()); |
| |
| // Make the clone. |
| Map* map = source->map(); |
| int object_size = map->instance_size(); |
| Object* clone; |
| |
| WriteBarrierMode wb_mode = UPDATE_WRITE_BARRIER; |
| |
| // 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 { |
| wb_mode = SKIP_WRITE_BARRIER; |
| { MaybeObject* maybe_clone = new_space_.AllocateRaw(object_size); |
| if (!maybe_clone->ToObject(&clone)) return maybe_clone; |
| } |
| SLOW_ASSERT(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); |
| } |
| |
| SLOW_ASSERT( |
| JSObject::cast(clone)->GetElementsKind() == source->GetElementsKind()); |
| FixedArrayBase* elements = FixedArrayBase::cast(source->elements()); |
| FixedArray* properties = FixedArray::cast(source->properties()); |
| // Update elements if necessary. |
| if (elements->length() > 0) { |
| Object* elem; |
| { MaybeObject* maybe_elem; |
| if (elements->map() == fixed_cow_array_map()) { |
| maybe_elem = FixedArray::cast(elements); |
| } else if (source->HasFastDoubleElements()) { |
| maybe_elem = CopyFixedDoubleArray(FixedDoubleArray::cast(elements)); |
| } else { |
| maybe_elem = CopyFixedArray(FixedArray::cast(elements)); |
| } |
| if (!maybe_elem->ToObject(&elem)) return maybe_elem; |
| } |
| JSObject::cast(clone)->set_elements(FixedArrayBase::cast(elem), wb_mode); |
| } |
| // 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), wb_mode); |
| } |
| // Return the new clone. |
| return clone; |
| } |
| |
| |
| MaybeObject* Heap::ReinitializeJSReceiver( |
| JSReceiver* object, InstanceType type, int size) { |
| ASSERT(type >= FIRST_JS_OBJECT_TYPE); |
| |
| // Allocate fresh map. |
| // TODO(rossberg): Once we optimize proxies, cache these maps. |
| Map* map; |
| MaybeObject* maybe = AllocateMap(type, size); |
| if (!maybe->To<Map>(&map)) return maybe; |
| |
| // Check that the receiver has at least the size of the fresh object. |
| int size_difference = object->map()->instance_size() - map->instance_size(); |
| ASSERT(size_difference >= 0); |
| |
| map->set_prototype(object->map()->prototype()); |
| |
| // Allocate the backing storage for the properties. |
| int prop_size = map->unused_property_fields() - map->inobject_properties(); |
| Object* properties; |
| maybe = AllocateFixedArray(prop_size, TENURED); |
| if (!maybe->ToObject(&properties)) return maybe; |
| |
| // Functions require some allocation, which might fail here. |
| SharedFunctionInfo* shared = NULL; |
| if (type == JS_FUNCTION_TYPE) { |
| String* name; |
| maybe = LookupAsciiSymbol("<freezing call trap>"); |
| if (!maybe->To<String>(&name)) return maybe; |
| maybe = AllocateSharedFunctionInfo(name); |
| if (!maybe->To<SharedFunctionInfo>(&shared)) return maybe; |
| } |
| |
| // Because of possible retries of this function after failure, |
| // we must NOT fail after this point, where we have changed the type! |
| |
| // Reset the map for the object. |
| object->set_map(map); |
| JSObject* jsobj = JSObject::cast(object); |
| |
| // Reinitialize the object from the constructor map. |
| InitializeJSObjectFromMap(jsobj, FixedArray::cast(properties), map); |
| |
| // Functions require some minimal initialization. |
| if (type == JS_FUNCTION_TYPE) { |
| map->set_function_with_prototype(true); |
| InitializeFunction(JSFunction::cast(object), shared, the_hole_value()); |
| JSFunction::cast(object)->set_context( |
| isolate()->context()->global_context()); |
| } |
| |
| // Put in filler if the new object is smaller than the old. |
| if (size_difference > 0) { |
| CreateFillerObjectAt( |
| object->address() + map->instance_size(), size_difference); |
| } |
| |
| return object; |
| } |
| |
| |
| 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) { |
| if (string.length() == 1) { |
| return Heap::LookupSingleCharacterStringFromCode(string[0]); |
| } |
| 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) { |
| // Count the number of characters in the UTF-8 string and check if |
| // it is an ASCII string. |
| Access<UnicodeCache::Utf8Decoder> |
| decoder(isolate_->unicode_cache()->utf8_decoder()); |
| decoder->Reset(string.start(), string.length()); |
| int chars = 0; |
| while (decoder->has_more()) { |
| uint32_t r = decoder->GetNext(); |
| if (r <= unibrow::Utf16::kMaxNonSurrogateCharCode) { |
| chars++; |
| } else { |
| chars += 2; |
| } |
| } |
| |
| 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()); |
| int i = 0; |
| while (i < chars) { |
| uint32_t r = decoder->GetNext(); |
| if (r > unibrow::Utf16::kMaxNonSurrogateCharCode) { |
| string_result->Set(i++, unibrow::Utf16::LeadSurrogate(r)); |
| string_result->Set(i++, unibrow::Utf16::TrailSurrogate(r)); |
| } else { |
| 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. |
| switch (string->map()->instance_type()) { |
| case STRING_TYPE: return symbol_map(); |
| case ASCII_STRING_TYPE: return ascii_symbol_map(); |
| case CONS_STRING_TYPE: return cons_symbol_map(); |
| case CONS_ASCII_STRING_TYPE: return cons_ascii_symbol_map(); |
| case EXTERNAL_STRING_TYPE: return external_symbol_map(); |
| case EXTERNAL_ASCII_STRING_TYPE: return external_ascii_symbol_map(); |
| case EXTERNAL_STRING_WITH_ASCII_DATA_TYPE: |
| return external_symbol_with_ascii_data_map(); |
| case SHORT_EXTERNAL_STRING_TYPE: return short_external_symbol_map(); |
| case SHORT_EXTERNAL_ASCII_STRING_TYPE: |
| return short_external_ascii_symbol_map(); |
| case SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE: |
| return short_external_symbol_with_ascii_data_map(); |
| default: return NULL; // No match found. |
| } |
| } |
| |
| |
| 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->Utf16Length()); |
| // 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 > Page::kMaxNonCodeHeapObjectSize) |
| ? lo_space_->AllocateRaw(size, NOT_EXECUTABLE) |
| : old_data_space_->AllocateRaw(size); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| |
| reinterpret_cast<HeapObject*>(result)->set_map_no_write_barrier(map); |
| // Set length and hash fields of the allocated string. |
| String* answer = String::cast(result); |
| answer->set_length(chars); |
| answer->set_hash_field(hash_field); |
| |
| ASSERT_EQ(size, answer->Size()); |
| |
| // Fill in the characters. |
| int i = 0; |
| while (i < chars) { |
| uint32_t character = buffer->GetNext(); |
| if (character > unibrow::Utf16::kMaxNonSurrogateCharCode) { |
| answer->Set(i++, unibrow::Utf16::LeadSurrogate(character)); |
| answer->Set(i++, unibrow::Utf16::TrailSurrogate(character)); |
| } else { |
| answer->Set(i++, character); |
| } |
| } |
| 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 > Page::kMaxNonCodeHeapObjectSize) { |
| // Allocate in new space, retry in large object space. |
| retry_space = LO_SPACE; |
| } |
| } else if (space == OLD_DATA_SPACE && |
| size > Page::kMaxNonCodeHeapObjectSize) { |
| 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_no_write_barrier(ascii_string_map()); |
| String::cast(result)->set_length(length); |
| String::cast(result)->set_hash_field(String::kEmptyHashField); |
| ASSERT_EQ(size, HeapObject::cast(result)->Size()); |
| |
| #ifdef DEBUG |
| if (FLAG_verify_heap) { |
| // Initialize string's content to ensure ASCII-ness (character range 0-127) |
| // as required when verifying the heap. |
| char* dest = SeqAsciiString::cast(result)->GetChars(); |
| memset(dest, 0x0F, length * kCharSize); |
| } |
| #endif // DEBUG |
| |
| 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 > Page::kMaxNonCodeHeapObjectSize) { |
| // Allocate in new space, retry in large object space. |
| retry_space = LO_SPACE; |
| } |
| } else if (space == OLD_DATA_SPACE && |
| size > Page::kMaxNonCodeHeapObjectSize) { |
| 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_no_write_barrier(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::AllocateJSArray( |
| ElementsKind elements_kind, |
| PretenureFlag pretenure) { |
| Context* global_context = isolate()->context()->global_context(); |
| JSFunction* array_function = global_context->array_function(); |
| Map* map = array_function->initial_map(); |
| Object* maybe_map_array = global_context->js_array_maps(); |
| if (!maybe_map_array->IsUndefined()) { |
| Object* maybe_transitioned_map = |
| FixedArray::cast(maybe_map_array)->get(elements_kind); |
| if (!maybe_transitioned_map->IsUndefined()) { |
| map = Map::cast(maybe_transitioned_map); |
| } |
| } |
| |
| return AllocateJSObjectFromMap(map, pretenure); |
| } |
| |
| |
| 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_no_write_barrier( |
| 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_->AllocateRaw(size, NOT_EXECUTABLE); |
| } |
| |
| |
| 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 (InNewSpace(obj)) { |
| HeapObject* dst = HeapObject::cast(obj); |
| dst->set_map_no_write_barrier(map); |
| CopyBlock(dst->address() + kPointerSize, |
| src->address() + kPointerSize, |
| FixedArray::SizeFor(len) - kPointerSize); |
| return obj; |
| } |
| HeapObject::cast(obj)->set_map_no_write_barrier(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::CopyFixedDoubleArrayWithMap(FixedDoubleArray* src, |
| Map* map) { |
| int len = src->length(); |
| Object* obj; |
| { MaybeObject* maybe_obj = AllocateRawFixedDoubleArray(len, NOT_TENURED); |
| if (!maybe_obj->ToObject(&obj)) return maybe_obj; |
| } |
| HeapObject* dst = HeapObject::cast(obj); |
| dst->set_map_no_write_barrier(map); |
| CopyBlock( |
| dst->address() + FixedDoubleArray::kLengthOffset, |
| src->address() + FixedDoubleArray::kLengthOffset, |
| FixedDoubleArray::SizeFor(len) - FixedDoubleArray::kLengthOffset); |
| return obj; |
| } |
| |
| |
| 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_no_write_barrier(fixed_array_map()); |
| array->set_length(length); |
| // Initialize body. |
| ASSERT(!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 > Page::kMaxNonCodeHeapObjectSize) { |
| // Too big for old pointer space. |
| space = LO_SPACE; |
| } |
| |
| AllocationSpace retry_space = |
| (size <= Page::kMaxNonCodeHeapObjectSize) ? OLD_POINTER_SPACE : LO_SPACE; |
| |
| return AllocateRaw(size, space, retry_space); |
| } |
| |
| |
| MUST_USE_RESULT static MaybeObject* AllocateFixedArrayWithFiller( |
| Heap* heap, |
| 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_no_write_barrier(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(this, |
| length, |
| pretenure, |
| undefined_value()); |
| } |
| |
| |
| MaybeObject* Heap::AllocateFixedArrayWithHoles(int length, |
| PretenureFlag pretenure) { |
| return AllocateFixedArrayWithFiller(this, |
| 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_no_write_barrier( |
| fixed_array_map()); |
| FixedArray::cast(obj)->set_length(length); |
| return obj; |
| } |
| |
| |
| MaybeObject* Heap::AllocateEmptyFixedDoubleArray() { |
| int size = FixedDoubleArray::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<FixedDoubleArray*>(result)->set_map_no_write_barrier( |
| fixed_double_array_map()); |
| reinterpret_cast<FixedDoubleArray*>(result)->set_length(0); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateUninitializedFixedDoubleArray( |
| int length, |
| PretenureFlag pretenure) { |
| if (length == 0) return empty_fixed_array(); |
| |
| Object* elements_object; |
| MaybeObject* maybe_obj = AllocateRawFixedDoubleArray(length, pretenure); |
| if (!maybe_obj->ToObject(&elements_object)) return maybe_obj; |
| FixedDoubleArray* elements = |
| reinterpret_cast<FixedDoubleArray*>(elements_object); |
| |
| elements->set_map_no_write_barrier(fixed_double_array_map()); |
| elements->set_length(length); |
| return elements; |
| } |
| |
| |
| MaybeObject* Heap::AllocateFixedDoubleArrayWithHoles( |
| int length, |
| PretenureFlag pretenure) { |
| if (length == 0) return empty_fixed_array(); |
| |
| Object* elements_object; |
| MaybeObject* maybe_obj = AllocateRawFixedDoubleArray(length, pretenure); |
| if (!maybe_obj->ToObject(&elements_object)) return maybe_obj; |
| FixedDoubleArray* elements = |
| reinterpret_cast<FixedDoubleArray*>(elements_object); |
| |
| for (int i = 0; i < length; ++i) { |
| elements->set_the_hole(i); |
| } |
| |
| elements->set_map_no_write_barrier(fixed_double_array_map()); |
| elements->set_length(length); |
| return elements; |
| } |
| |
| |
| MaybeObject* Heap::AllocateRawFixedDoubleArray(int length, |
| PretenureFlag pretenure) { |
| if (length < 0 || length > FixedDoubleArray::kMaxLength) { |
| return Failure::OutOfMemoryException(); |
| } |
| |
| AllocationSpace space = |
| (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| int size = FixedDoubleArray::SizeFor(length); |
| |
| #ifndef V8_HOST_ARCH_64_BIT |
| size += kPointerSize; |
| #endif |
| |
| if (space == NEW_SPACE && size > kMaxObjectSizeInNewSpace) { |
| // Too big for new space. |
| space = LO_SPACE; |
| } else if (space == OLD_DATA_SPACE && |
| size > Page::kMaxNonCodeHeapObjectSize) { |
| // Too big for old data space. |
| space = LO_SPACE; |
| } |
| |
| AllocationSpace retry_space = |
| (size <= Page::kMaxNonCodeHeapObjectSize) ? OLD_DATA_SPACE : LO_SPACE; |
| |
| HeapObject* object; |
| { MaybeObject* maybe_object = AllocateRaw(size, space, retry_space); |
| if (!maybe_object->To<HeapObject>(&object)) return maybe_object; |
| } |
| |
| return EnsureDoubleAligned(this, object, size); |
| } |
| |
| |
| MaybeObject* Heap::AllocateHashTable(int length, PretenureFlag pretenure) { |
| Object* result; |
| { MaybeObject* maybe_result = AllocateFixedArray(length, pretenure); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| reinterpret_cast<HeapObject*>(result)->set_map_no_write_barrier( |
| hash_table_map()); |
| ASSERT(result->IsHashTable()); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateGlobalContext() { |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateFixedArray(Context::GLOBAL_CONTEXT_SLOTS); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map_no_write_barrier(global_context_map()); |
| context->set_js_array_maps(undefined_value()); |
| ASSERT(context->IsGlobalContext()); |
| ASSERT(result->IsContext()); |
| return result; |
| } |
| |
| |
| MaybeObject* Heap::AllocateModuleContext(ScopeInfo* scope_info) { |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateFixedArray(scope_info->ContextLength(), TENURED); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map_no_write_barrier(module_context_map()); |
| // Context links will be set later. |
| context->set_extension(Smi::FromInt(0)); |
| return context; |
| } |
| |
| |
| MaybeObject* Heap::AllocateFunctionContext(int length, JSFunction* function) { |
| ASSERT(length >= Context::MIN_CONTEXT_SLOTS); |
| Object* result; |
| { MaybeObject* maybe_result = AllocateFixedArray(length); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map_no_write_barrier(function_context_map()); |
| context->set_closure(function); |
| context->set_previous(function->context()); |
| context->set_extension(Smi::FromInt(0)); |
| context->set_global(function->context()->global()); |
| return context; |
| } |
| |
| |
| MaybeObject* Heap::AllocateCatchContext(JSFunction* function, |
| Context* previous, |
| String* name, |
| Object* thrown_object) { |
| STATIC_ASSERT(Context::MIN_CONTEXT_SLOTS == Context::THROWN_OBJECT_INDEX); |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateFixedArray(Context::MIN_CONTEXT_SLOTS + 1); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map_no_write_barrier(catch_context_map()); |
| context->set_closure(function); |
| context->set_previous(previous); |
| context->set_extension(name); |
| context->set_global(previous->global()); |
| context->set(Context::THROWN_OBJECT_INDEX, thrown_object); |
| return context; |
| } |
| |
| |
| MaybeObject* Heap::AllocateWithContext(JSFunction* function, |
| Context* previous, |
| JSObject* extension) { |
| Object* result; |
| { MaybeObject* maybe_result = AllocateFixedArray(Context::MIN_CONTEXT_SLOTS); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map_no_write_barrier(with_context_map()); |
| context->set_closure(function); |
| context->set_previous(previous); |
| context->set_extension(extension); |
| context->set_global(previous->global()); |
| return context; |
| } |
| |
| |
| MaybeObject* Heap::AllocateBlockContext(JSFunction* function, |
| Context* previous, |
| ScopeInfo* scope_info) { |
| Object* result; |
| { MaybeObject* maybe_result = |
| AllocateFixedArrayWithHoles(scope_info->ContextLength()); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map_no_write_barrier(block_context_map()); |
| context->set_closure(function); |
| context->set_previous(previous); |
| context->set_extension(scope_info); |
| context->set_global(previous->global()); |
| return context; |
| } |
| |
| |
| MaybeObject* Heap::AllocateScopeInfo(int length) { |
| FixedArray* scope_info; |
| MaybeObject* maybe_scope_info = AllocateFixedArray(length, TENURED); |
| if (!maybe_scope_info->To(&scope_info)) return maybe_scope_info; |
| scope_info->set_map_no_write_barrier(scope_info_map()); |
| return scope_info; |
| } |
| |
| |
| 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 > Page::kMaxNonCodeHeapObjectSize) ? LO_SPACE : OLD_POINTER_SPACE; |
| Object* result; |
| { MaybeObject* maybe_result = Allocate(map, space); |
| if (!maybe_result->ToObject(&result)) return maybe_result; |
| } |
| Struct::cast(result)->InitializeBody(size); |
| return result; |
| } |
| |
| |
| bool Heap::IsHeapIterable() { |
| return (!old_pointer_space()->was_swept_conservatively() && |
| !old_data_space()->was_swept_conservatively()); |
| } |
| |
| |
| void Heap::EnsureHeapIsIterable() { |
| ASSERT(IsAllocationAllowed()); |
| if (!IsHeapIterable()) { |
| CollectAllGarbage(kMakeHeapIterableMask, "Heap::EnsureHeapIsIterable"); |
| } |
| ASSERT(IsHeapIterable()); |
| } |
| |
| |
| void Heap::AdvanceIdleIncrementalMarking(intptr_t step_size) { |
| incremental_marking()->Step(step_size, |
| IncrementalMarking::NO_GC_VIA_STACK_GUARD); |
| |
| if (incremental_marking()->IsComplete()) { |
| bool uncommit = false; |
| if (gc_count_at_last_idle_gc_ == gc_count_) { |
| // No GC since the last full GC, the mutator is probably not active. |
| isolate_->compilation_cache()->Clear(); |
| uncommit = true; |
| } |
| CollectAllGarbage(kNoGCFlags, "idle notification: finalize incremental"); |
| gc_count_at_last_idle_gc_ = gc_count_; |
| if (uncommit) { |
| new_space_.Shrink(); |
| UncommitFromSpace(); |
| } |
| } |
| } |
| |
| |
| bool Heap::IdleNotification(int hint) { |
| // Hints greater than this value indicate that |
| // the embedder is requesting a lot of GC work. |
| const int kMaxHint = 1000; |
| // Minimal hint that allows to do full GC. |
| const int kMinHintForFullGC = 100; |
| intptr_t size_factor = Min(Max(hint, 20), kMaxHint) / 4; |
| // The size factor is in range [5..250]. The numbers here are chosen from |
| // experiments. If you changes them, make sure to test with |
| // chrome/performance_ui_tests --gtest_filter="GeneralMixMemoryTest.* |
| intptr_t step_size = size_factor * IncrementalMarking::kAllocatedThreshold; |
| |
| if (contexts_disposed_ > 0) { |
| if (hint >= kMaxHint) { |
| // The embedder is requesting a lot of GC work after context disposal, |
| // we age inline caches so that they don't keep objects from |
| // the old context alive. |
| AgeInlineCaches(); |
| } |
| int mark_sweep_time = Min(TimeMarkSweepWouldTakeInMs(), 1000); |
| if (hint >= mark_sweep_time && !FLAG_expose_gc && |
| incremental_marking()->IsStopped()) { |
| HistogramTimerScope scope(isolate_->counters()->gc_context()); |
| CollectAllGarbage(kReduceMemoryFootprintMask, |
| "idle notification: contexts disposed"); |
| } else { |
| AdvanceIdleIncrementalMarking(step_size); |
| contexts_disposed_ = 0; |
| } |
| // Make sure that we have no pending context disposals. |
| // Take into account that we might have decided to delay full collection |
| // because incremental marking is in progress. |
| ASSERT((contexts_disposed_ == 0) || !incremental_marking()->IsStopped()); |
| // After context disposal there is likely a lot of garbage remaining, reset |
| // the idle notification counters in order to trigger more incremental GCs |
| // on subsequent idle notifications. |
| StartIdleRound(); |
| return false; |
| } |
| |
| if (!FLAG_incremental_marking || FLAG_expose_gc || Serializer::enabled()) { |
| return IdleGlobalGC(); |
| } |
| |
| // By doing small chunks of GC work in each IdleNotification, |
| // perform a round of incremental GCs and after that wait until |
| // the mutator creates enough garbage to justify a new round. |
| // An incremental GC progresses as follows: |
| // 1. many incremental marking steps, |
| // 2. one old space mark-sweep-compact, |
| // 3. many lazy sweep steps. |
| // Use mark-sweep-compact events to count incremental GCs in a round. |
| |
| |
| if (incremental_marking()->IsStopped()) { |
| if (!IsSweepingComplete() && |
| !AdvanceSweepers(static_cast<int>(step_size))) { |
| return false; |
| } |
| } |
| |
| if (mark_sweeps_since_idle_round_started_ >= kMaxMarkSweepsInIdleRound) { |
| if (EnoughGarbageSinceLastIdleRound()) { |
| StartIdleRound(); |
| } else { |
| return true; |
| } |
| } |
| |
| int new_mark_sweeps = ms_count_ - ms_count_at_last_idle_notification_; |
| mark_sweeps_since_idle_round_started_ += new_mark_sweeps; |
| ms_count_at_last_idle_notification_ = ms_count_; |
| |
| int remaining_mark_sweeps = kMaxMarkSweepsInIdleRound - |
| mark_sweeps_since_idle_round_started_; |
| |
| if (remaining_mark_sweeps <= 0) { |
| FinishIdleRound(); |
| return true; |
| } |
| |
| if (incremental_marking()->IsStopped()) { |
| // If there are no more than two GCs left in this idle round and we are |
| // allowed to do a full GC, then make those GCs full in order to compact |
| // the code space. |
| // TODO(ulan): Once we enable code compaction for incremental marking, |
| // we can get rid of this special case and always start incremental marking. |
| if (remaining_mark_sweeps <= 2 && hint >= kMinHintForFullGC) { |
| CollectAllGarbage(kReduceMemoryFootprintMask, |
| "idle notification: finalize idle round"); |
| } else { |
| incremental_marking()->Start(); |
| } |
| } |
| if (!incremental_marking()->IsStopped()) { |
| AdvanceIdleIncrementalMarking(step_size); |
| } |
| return false; |
| } |
| |
| |
| bool Heap::IdleGlobalGC() { |
| 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; |
| |
| if (!last_idle_notification_gc_count_init_) { |
| last_idle_notification_gc_count_ = gc_count_; |
| last_idle_notification_gc_count_init_ = true; |
| } |
| |
| 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_idle_notification_gc_count_ < kGCsBetweenCleanup) { |
| number_idle_notifications_ = |
| Min(number_idle_notifications_ + 1, kMaxIdleCount); |
| } else { |
| number_idle_notifications_ = 0; |
| last_idle_notification_gc_count_ = gc_count_; |
| } |
| |
| if (number_idle_notifications_ == kIdlesBeforeScavenge) { |
| CollectGarbage(NEW_SPACE, "idle notification"); |
| new_space_.Shrink(); |
| last_idle_notification_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. |
| isolate_->compilation_cache()->Clear(); |
| |
| CollectAllGarbage(kReduceMemoryFootprintMask, "idle notification"); |
| new_space_.Shrink(); |
| last_idle_notification_gc_count_ = gc_count_; |
| |
| } else if (number_idle_notifications_ == kIdlesBeforeMarkCompact) { |
| CollectAllGarbage(kReduceMemoryFootprintMask, "idle notification"); |
| new_space_.Shrink(); |
| last_idle_notification_gc_count_ = gc_count_; |
| number_idle_notifications_ = 0; |
| finished = true; |
| } 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; |
| } |
| |
| if (uncommit) UncommitFromSpace(); |
| |
| return finished; |
| } |
| |
| |
| #ifdef DEBUG |
| |
| void Heap::Print() { |
| if (!HasBeenSetUp()) return; |
| isolate()->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("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("old_gen_limit_factor_ %d\n", old_gen_limit_factor_); |
| |
| PrintF("\n"); |
| PrintF("Number of handles : %d\n", HandleScope::NumberOfHandles()); |
| isolate_->global_handles()->PrintStats(); |
| PrintF("\n"); |
| |
| PrintF("Heap statistics : "); |
| isolate_->memory_allocator()->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 |
| void Heap::Verify() { |
| ASSERT(HasBeenSetUp()); |
| |
| store_buffer()->Verify(); |
| |
| VerifyPointersVisitor visitor; |
| IterateRoots(&visitor, VISIT_ONLY_STRONG); |
| |
| new_space_.Verify(); |
| |
| old_pointer_space_->Verify(&visitor); |
| map_space_->Verify(&visitor); |
| |
| 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::LookupAsciiSymbol(Handle<SeqAsciiString> string, |
| int from, |
| int length) { |
| Object* symbol = NULL; |
| Object* new_table; |
| { MaybeObject* maybe_new_table = |
| symbol_table()->LookupSubStringAsciiSymbol(string, |
| from, |
| length, |
| &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() { |
| NewSpacePageIterator it(new_space_.FromSpaceStart(), |
| new_space_.FromSpaceEnd()); |
| while (it.has_next()) { |
| NewSpacePage* page = it.next(); |
| for (Address cursor = page->area_start(), limit = page->area_end(); |
| cursor < limit; |
| cursor += kPointerSize) { |
| Memory::Address_at(cursor) = kFromSpaceZapValue; |
| } |
| } |
| } |
| #endif // DEBUG |
| |
| |
| void Heap::IterateAndMarkPointersToFromSpace(Address start, |
| Address end, |
| ObjectSlotCallback callback) { |
| Address slot_address = start; |
| |
| // We are not collecting slots on new space objects during mutation |
| // thus we have to scan for pointers to evacuation candidates when we |
| // promote objects. But we should not record any slots in non-black |
| // objects. Grey object's slots would be rescanned. |
| // White object might not survive until the end of collection |
| // it would be a violation of the invariant to record it's slots. |
| bool record_slots = false; |
| if (incremental_marking()->IsCompacting()) { |
| MarkBit mark_bit = Marking::MarkBitFrom(HeapObject::FromAddress(start)); |
| record_slots = Marking::IsBlack(mark_bit); |
| } |
| |
| while (slot_address < end) { |
| Object** slot = reinterpret_cast<Object**>(slot_address); |
| Object* object = *slot; |
| // If the store buffer becomes overfull we mark pages as being exempt from |
| // the store buffer. These pages are scanned to find pointers that point |
| // to the new space. In that case we may hit newly promoted objects and |
| // fix the pointers before the promotion queue gets to them. Thus the 'if'. |
| if (object->IsHeapObject()) { |
| if (Heap::InFromSpace(object)) { |
| callback(reinterpret_cast<HeapObject**>(slot), |
| HeapObject::cast(object)); |
| Object* new_object = *slot; |
| if (InNewSpace(new_object)) { |
| SLOW_ASSERT(Heap::InToSpace(new_object)); |
| SLOW_ASSERT(new_object->IsHeapObject()); |
| store_buffer_.EnterDirectlyIntoStoreBuffer( |
| reinterpret_cast<Address>(slot)); |
| } |
| SLOW_ASSERT(!MarkCompactCollector::IsOnEvacuationCandidate(new_object)); |
| } else if (record_slots && |
| MarkCompactCollector::IsOnEvacuationCandidate(object)) { |
| mark_compact_collector()->RecordSlot(slot, slot, object); |
| } |
| } |
| slot_address += kPointerSize; |
| } |
| } |
| |
| |
| #ifdef DEBUG |
| typedef bool (*CheckStoreBufferFilter)(Object** addr); |
| |
| |
| bool IsAMapPointerAddress(Object** addr) { |
| uintptr_t a = reinterpret_cast<uintptr_t>(addr); |
| int mod = a % Map::kSize; |
| return mod >= Map::kPointerFieldsBeginOffset && |
| mod < Map::kPointerFieldsEndOffset; |
| } |
| |
| |
| bool EverythingsAPointer(Object** addr) { |
| return true; |
| } |
| |
| |
| static void CheckStoreBuffer(Heap* heap, |
| Object** current, |
| Object** limit, |
| Object**** store_buffer_position, |
| Object*** store_buffer_top, |
| CheckStoreBufferFilter filter, |
| Address special_garbage_start, |
| Address special_garbage_end) { |
| Map* free_space_map = heap->free_space_map(); |
| for ( ; current < limit; current++) { |
| Object* o = *current; |
| Address current_address = reinterpret_cast<Address>(current); |
| // Skip free space. |
| if (o == free_space_map) { |
| Address current_address = reinterpret_cast<Address>(current); |
| FreeSpace* free_space = |
| FreeSpace::cast(HeapObject::FromAddress(current_address)); |
| int skip = free_space->Size(); |
| ASSERT(current_address + skip <= reinterpret_cast<Address>(limit)); |
| ASSERT(skip > 0); |
| current_address += skip - kPointerSize; |
| current = reinterpret_cast<Object**>(current_address); |
| continue; |
| } |
| // Skip the current linear allocation space between top and limit which is |
| // unmarked with the free space map, but can contain junk. |
| if (current_address == special_garbage_start && |
| special_garbage_end != special_garbage_start) { |
| current_address = special_garbage_end - kPointerSize; |
| current = reinterpret_cast<Object**>(current_address); |
| continue; |
| } |
| if (!(*filter)(current)) continue; |
| ASSERT(current_address < special_garbage_start || |
| current_address >= special_garbage_end); |
| ASSERT(reinterpret_cast<uintptr_t>(o) != kFreeListZapValue); |
| // We have to check that the pointer does not point into new space |
| // without trying to cast it to a heap object since the hash field of |
| // a string can contain values like 1 and 3 which are tagged null |
| // pointers. |
| if (!heap->InNewSpace(o)) continue; |
| while (**store_buffer_position < current && |
| *store_buffer_position < store_buffer_top) { |
| (*store_buffer_position)++; |
| } |
| if (**store_buffer_position != current || |
| *store_buffer_position == store_buffer_top) { |
| Object** obj_start = current; |
| while (!(*obj_start)->IsMap()) obj_start--; |
| UNREACHABLE(); |
| } |
| } |
| } |
| |
| |
| // Check that the store buffer contains all intergenerational pointers by |
| // scanning a page and ensuring that all pointers to young space are in the |
| // store buffer. |
| void Heap::OldPointerSpaceCheckStoreBuffer() { |
| OldSpace* space = old_pointer_space(); |
| PageIterator pages(space); |
| |
| store_buffer()->SortUniq(); |
| |
| while (pages.has_next()) { |
| Page* page = pages.next(); |
| Object** current = reinterpret_cast<Object**>(page->area_start()); |
| |
| Address end = page->area_end(); |
| |
| Object*** store_buffer_position = store_buffer()->Start(); |
| Object*** store_buffer_top = store_buffer()->Top(); |
| |
| Object** limit = reinterpret_cast<Object**>(end); |
| CheckStoreBuffer(this, |
| current, |
| limit, |
| &store_buffer_position, |
| store_buffer_top, |
| &EverythingsAPointer, |
| space->top(), |
| space->limit()); |
| } |
| } |
| |
| |
| void Heap::MapSpaceCheckStoreBuffer() { |
| MapSpace* space = map_space(); |
| PageIterator pages(space); |
| |
| store_buffer()->SortUniq(); |
| |
| while (pages.has_next()) { |
| Page* page = pages.next(); |
| Object** current = reinterpret_cast<Object**>(page->area_start()); |
| |
| Address end = page->area_end(); |
| |
| Object*** store_buffer_position = store_buffer()->Start(); |
| Object*** store_buffer_top = store_buffer()->Top(); |
| |
| Object** limit = reinterpret_cast<Object**>(end); |
| CheckStoreBuffer(this, |
| current, |
| limit, |
| &store_buffer_position, |
| store_buffer_top, |
| &IsAMapPointerAddress, |
| space->top(), |
| space->limit()); |
| } |
| } |
| |
| |
| void Heap::LargeObjectSpaceCheckStoreBuffer() { |
| LargeObjectIterator it(lo_space()); |
| for (HeapObject* object = it.Next(); object != NULL; object = it.Next()) { |
| // We only have code, sequential strings, or fixed arrays in large |
| // object space, and only fixed arrays can possibly contain pointers to |
| // the young generation. |
| if (object->IsFixedArray()) { |
| Object*** store_buffer_position = store_buffer()->Start(); |
| Object*** store_buffer_top = store_buffer()->Top(); |
| Object** current = reinterpret_cast<Object**>(object->address()); |
| Object** limit = |
| reinterpret_cast<Object**>(object->address() + object->Size()); |
| CheckStoreBuffer(this, |
| current, |
| limit, |
| &store_buffer_position, |
| store_buffer_top, |
| &EverythingsAPointer, |
| NULL, |
| NULL); |
| } |
| } |
| } |
| #endif |
| |
| |
| 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(VisitorSynchronization::kSymbolTable); |
| if (mode != VISIT_ALL_IN_SCAVENGE && |
| mode != VISIT_ALL_IN_SWEEP_NEWSPACE) { |
| // Scavenge collections have special processing for this. |
| external_string_table_.Iterate(v); |
| } |
| v->Synchronize(VisitorSynchronization::kExternalStringsTable); |
| } |
| |
| |
| void Heap::IterateStrongRoots(ObjectVisitor* v, VisitMode mode) { |
| v->VisitPointers(&roots_[0], &roots_[kStrongRootListLength]); |
| v->Synchronize(VisitorSynchronization::kStrongRootList); |
| |
| v->VisitPointer(BitCast<Object**>(&hidden_symbol_)); |
| v->Synchronize(VisitorSynchronization::kSymbol); |
| |
| isolate_->bootstrapper()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kBootstrapper); |
| isolate_->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kTop); |
| Relocatable::Iterate(v); |
| v->Synchronize(VisitorSynchronization::kRelocatable); |
| |
| #ifdef ENABLE_DEBUGGER_SUPPORT |
| isolate_->debug()->Iterate(v); |
| if (isolate_->deoptimizer_data() != NULL) { |
| isolate_->deoptimizer_data()->Iterate(v); |
| } |
| #endif |
| v->Synchronize(VisitorSynchronization::kDebug); |
| isolate_->compilation_cache()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kCompilationCache); |
| |
| // Iterate over local handles in handle scopes. |
| isolate_->handle_scope_implementer()->Iterate(v); |
| isolate_->IterateDeferredHandles(v); |
| v->Synchronize(VisitorSynchronization::kHandleScope); |
| |
| // Iterate over the builtin code objects and code stubs in the |
| // heap. Note that it is not necessary to iterate over code objects |
| // on scavenge collections. |
| if (mode != VISIT_ALL_IN_SCAVENGE) { |
| isolate_->builtins()->IterateBuiltins(v); |
| } |
| v->Synchronize(VisitorSynchronization::kBuiltins); |
| |
| // Iterate over global handles. |
| switch (mode) { |
| case VISIT_ONLY_STRONG: |
| isolate_->global_handles()->IterateStrongRoots(v); |
| break; |
| case VISIT_ALL_IN_SCAVENGE: |
| isolate_->global_handles()->IterateNewSpaceStrongAndDependentRoots(v); |
| break; |
| case VISIT_ALL_IN_SWEEP_NEWSPACE: |
| case VISIT_ALL: |
| isolate_->global_handles()->IterateAllRoots(v); |
| break; |
| } |
| v->Synchronize(VisitorSynchronization::kGlobalHandles); |
| |
| // Iterate over pointers being held by inactive threads. |
| isolate_->thread_manager()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kThreadManager); |
| |
| // 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. |
| } |
| |
| |
| // 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, |
| intptr_t max_old_gen_size, |
| intptr_t max_executable_size) { |
| if (HasBeenSetUp()) return false; |
| |
| if (FLAG_stress_compaction) { |
| // This will cause more frequent GCs when stressing. |
| max_semispace_size_ = Page::kPageSize; |
| } |
| |
| if (max_semispace_size > 0) { |
| if (max_semispace_size < Page::kPageSize) { |
| max_semispace_size = Page::kPageSize; |
| if (FLAG_trace_gc) { |
| PrintPID("Max semispace size cannot be less than %dkbytes\n", |
| Page::kPageSize >> 10); |
| } |
| } |
| 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_; |
| if (FLAG_trace_gc) { |
| PrintPID("Max semispace size cannot be more than %dkbytes\n", |
| reserved_semispace_size_ >> 10); |
| } |
| } |
| } 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 and needs at least one page for each space. |
| int paged_space_count = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1; |
| max_old_generation_size_ = Max(static_cast<intptr_t>(paged_space_count * |
| Page::kPageSize), |
| RoundUp(max_old_generation_size_, |
| Page::kPageSize)); |
| |
| configured_ = true; |
| return true; |
| } |
| |
| |
| bool Heap::ConfigureHeapDefault() { |
| return ConfigureHeap(static_cast<intptr_t>(FLAG_max_new_space_size / 2) * KB, |
| static_cast<intptr_t>(FLAG_max_old_space_size) * MB, |
| static_cast<intptr_t>(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_->SizeOfObjects(); |
| *stats->old_pointer_space_capacity = old_pointer_space_->Capacity(); |
| *stats->old_data_space_size = old_data_space_->SizeOfObjects(); |
| *stats->old_data_space_capacity = old_data_space_->Capacity(); |
| *stats->code_space_size = code_space_->SizeOfObjects(); |
| *stats->code_space_capacity = code_space_->Capacity(); |
| *stats->map_space_size = map_space_->SizeOfObjects(); |
| *stats->map_space_capacity = map_space_->Capacity(); |
| *stats->cell_space_size = cell_space_->SizeOfObjects(); |
| *stats->cell_space_capacity = cell_space_->Capacity(); |
| *stats->lo_space_size = lo_space_->Size(); |
| isolate_->global_handles()->RecordStats(stats); |
| *stats->memory_allocator_size = isolate()->memory_allocator()->Size(); |
| *stats->memory_allocator_capacity = |
| isolate()->memory_allocator()->Size() + |
| isolate()->memory_allocator()->Available(); |
| *stats->os_error = OS::GetLastError(); |
| isolate()->memory_allocator()->Available(); |
| if (take_snapshot) { |
| HeapIterator iterator; |
| 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::PromotedSpaceSizeOfObjects() { |
| return old_pointer_space_->SizeOfObjects() |
| + old_data_space_->SizeOfObjects() |
| + code_space_->SizeOfObjects() |
| + map_space_->SizeOfObjects() |
| + cell_space_->SizeOfObjects() |
| + lo_space_->SizeOfObjects(); |
| } |
| |
| |
| intptr_t Heap::PromotedExternalMemorySize() { |
| if (amount_of_external_allocated_memory_ |
| <= amount_of_external_allocated_memory_at_last_global_gc_) return 0; |
| return amount_of_external_allocated_memory_ |
| - amount_of_external_allocated_memory_at_last_global_gc_; |
| } |
| |
| #ifdef DEBUG |
| |
| // Tags 0, 1, and 3 are used. Use 2 for marking visited HeapObject. |
| static const int kMarkTag = 2; |
| |
| |
| class HeapDebugUtils { |
| public: |
| explicit HeapDebugUtils(Heap* heap) |
| : search_for_any_global_(false), |
| search_target_(NULL), |
| found_target_(false), |
| object_stack_(20), |
| heap_(heap) { |
| } |
| |
| class MarkObjectVisitor : public ObjectVisitor { |
| public: |
| explicit MarkObjectVisitor(HeapDebugUtils* utils) : utils_(utils) { } |
| |
| void VisitPointers(Object** start, Object** end) { |
| // Copy all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) |
| utils_->MarkObjectRecursively(p); |
| } |
| } |
| |
| HeapDebugUtils* utils_; |
| }; |
| |
| void MarkObjectRecursively(Object** p) { |
| if (!(*p)->IsHeapObject()) return; |
| |
| HeapObject* obj = HeapObject::cast(*p); |
| |
| Object* map = obj->map(); |
| |
| if (!map->IsHeapObject()) return; // visited before |
| |
| if (found_target_) return; // stop if target found |
| object_stack_.Add(obj); |
| if ((search_for_any_global_ && obj->IsJSGlobalObject()) || |
| (!search_for_any_global_ && (obj == search_target_))) { |
| found_target_ = true; |
| return; |
| } |
| |
| // not visited yet |
| Map* map_p = reinterpret_cast<Map*>(HeapObject::cast(map)); |
| |
| Address map_addr = map_p->address(); |
| |
| obj->set_map_no_write_barrier(reinterpret_cast<Map*>(map_addr + kMarkTag)); |
| |
| MarkObjectRecursively(&map); |
| |
| MarkObjectVisitor mark_visitor(this); |
| |
| obj->IterateBody(map_p->instance_type(), obj->SizeFromMap(map_p), |
| &mark_visitor); |
| |
| if (!found_target_) // don't pop if found the target |
| object_stack_.RemoveLast(); |
| } |
| |
| |
| class UnmarkObjectVisitor : public ObjectVisitor { |
| public: |
| explicit UnmarkObjectVisitor(HeapDebugUtils* utils) : utils_(utils) { } |
| |
| void VisitPointers(Object** start, Object** end) { |
| // Copy all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) |
| utils_->UnmarkObjectRecursively(p); |
| } |
| } |
| |
| HeapDebugUtils* utils_; |
| }; |
| |
| |
| void UnmarkObjectRecursively(Object** p) { |
| 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_no_write_barrier(reinterpret_cast<Map*>(map_p)); |
| |
| UnmarkObjectRecursively(reinterpret_cast<Object**>(&map_p)); |
| |
| UnmarkObjectVisitor unmark_visitor(this); |
| |
| obj->IterateBody(Map::cast(map_p)->instance_type(), |
| obj->SizeFromMap(Map::cast(map_p)), |
| &unmark_visitor); |
| } |
| |
| |
| void MarkRootObjectRecursively(Object** root) { |
| if (search_for_any_global_) { |
| ASSERT(search_target_ == NULL); |
| } else { |
| ASSERT(search_target_->IsHeapObject()); |
| } |
| found_target_ = false; |
| object_stack_.Clear(); |
| |
| MarkObjectRecursively(root); |
| UnmarkObjectRecursively(root); |
| |
| 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"); |
| } |
| } |
| |
| // Helper class for visiting HeapObjects recursively. |
| class MarkRootVisitor: public ObjectVisitor { |
| public: |
| explicit MarkRootVisitor(HeapDebugUtils* utils) : utils_(utils) { } |
| |
| void VisitPointers(Object** start, Object** end) { |
| // Visit all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) |
| utils_->MarkRootObjectRecursively(p); |
| } |
| } |
| |
| HeapDebugUtils* utils_; |
| }; |
| |
| bool search_for_any_global_; |
| Object* search_target_; |
| bool found_target_; |
| List<Object*> object_stack_; |
| Heap* heap_; |
| |
| friend class Heap; |
| }; |
| |
| #endif |
| |
| |
| V8_DECLARE_ONCE(initialize_gc_once); |
| |
| static void InitializeGCOnce() { |
| InitializeScavengingVisitorsTables(); |
| NewSpaceScavenger::Initialize(); |
| MarkCompactCollector::Initialize(); |
| } |
| |
| bool Heap::SetUp(bool create_heap_objects) { |
| #ifdef DEBUG |
| allocation_timeout_ = FLAG_gc_interval; |
| debug_utils_ = new HeapDebugUtils(this); |
| #endif |
| |
| // Initialize heap spaces and initial maps and objects. Whenever something |
| // goes wrong, just return false. The caller should check the results and |
| // call Heap::TearDown() to release allocated memory. |
| // |
| // If the heap is not yet configured (e.g. through the API), configure it. |
| // Configuration is based on the flags new-space-size (really the semispace |
| // size) and old-space-size if set or the initial values of semispace_size_ |
| // and old_generation_size_ otherwise. |
| if (!configured_) { |
| if (!ConfigureHeapDefault()) return false; |
| } |
| |
| CallOnce(&initialize_gc_once, &InitializeGCOnce); |
| |
| MarkMapPointersAsEncoded(false); |
| |
| // Set up memory allocator. |
| if (!isolate_->memory_allocator()->SetUp(MaxReserved(), MaxExecutableSize())) |
| return false; |
| |
| // Set up new space. |
| if (!new_space_.SetUp(reserved_semispace_size_, max_semispace_size_)) { |
| return false; |
| } |
| |
| // Initialize old pointer space. |
| old_pointer_space_ = |
| new OldSpace(this, |
| max_old_generation_size_, |
| OLD_POINTER_SPACE, |
| NOT_EXECUTABLE); |
| if (old_pointer_space_ == NULL) return false; |
| if (!old_pointer_space_->SetUp()) return false; |
| |
| // Initialize old data space. |
| old_data_space_ = |
| new OldSpace(this, |
| max_old_generation_size_, |
| OLD_DATA_SPACE, |
| NOT_EXECUTABLE); |
| if (old_data_space_ == NULL) return false; |
| if (!old_data_space_->SetUp()) 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 (!isolate_->code_range()->SetUp(code_range_size_)) { |
| return false; |
| } |
| } |
| |
| code_space_ = |
| new OldSpace(this, max_old_generation_size_, CODE_SPACE, EXECUTABLE); |
| if (code_space_ == NULL) return false; |
| if (!code_space_->SetUp()) return false; |
| |
| // Initialize map space. |
| map_space_ = new MapSpace(this, max_old_generation_size_, MAP_SPACE); |
| if (map_space_ == NULL) return false; |
| if (!map_space_->SetUp()) return false; |
| |
| // Initialize global property cell space. |
| cell_space_ = new CellSpace(this, max_old_generation_size_, CELL_SPACE); |
| if (cell_space_ == NULL) return false; |
| if (!cell_space_->SetUp()) return false; |
| |
| // The large object code space may contain code or data. We set the memory |
| // to be non-executable here for safety, but this means we need to enable it |
| // explicitly when allocating large code objects. |
| lo_space_ = new LargeObjectSpace(this, max_old_generation_size_, LO_SPACE); |
| if (lo_space_ == NULL) return false; |
| if (!lo_space_->SetUp()) return false; |
| |
| // Set up the seed that is used to randomize the string hash function. |
| ASSERT(hash_seed() == 0); |
| if (FLAG_randomize_hashes) { |
| if (FLAG_hash_seed == 0) { |
| set_hash_seed( |
| Smi::FromInt(V8::RandomPrivate(isolate()) & 0x3fffffff)); |
| } else { |
| set_hash_seed(Smi::FromInt(FLAG_hash_seed)); |
| } |
| } |
| |
| 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(isolate_, IntPtrTEvent("heap-capacity", Capacity())); |
| LOG(isolate_, IntPtrTEvent("heap-available", Available())); |
| |
| store_buffer()->SetUp(); |
| |
| if (FLAG_parallel_recompilation) relocation_mutex_ = OS::CreateMutex(); |
| |
| return true; |
| } |
| |
| |
| void Heap::SetStackLimits() { |
| ASSERT(isolate_ != NULL); |
| ASSERT(isolate_ == isolate()); |
| // On 64 bit machines, pointers are generally out of range of Smis. We write |
| // something that looks like an out of range Smi to the GC. |
| |
| // Set up the special root array entries containing the stack limits. |
| // These are actually addresses, but the tag makes the GC ignore it. |
| roots_[kStackLimitRootIndex] = |
| reinterpret_cast<Object*>( |
| (isolate_->stack_guard()->jslimit() & ~kSmiTagMask) | kSmiTag); |
| roots_[kRealStackLimitRootIndex] = |
| reinterpret_cast<Object*>( |
| (isolate_->stack_guard()->real_jslimit() & ~kSmiTagMask) | kSmiTag); |
| } |
| |
| |
| void Heap::TearDown() { |
| #ifdef DEBUG |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| if (FLAG_print_cumulative_gc_stat) { |
| PrintF("\n\n"); |
| PrintF("gc_count=%d ", gc_count_); |
| PrintF("mark_sweep_count=%d ", ms_count_); |
| PrintF("max_gc_pause=%d ", get_max_gc_pause()); |
| PrintF("min_in_mutator=%d ", get_min_in_mutator()); |
| PrintF("max_alive_after_gc=%" V8_PTR_PREFIX "d ", |
| get_max_alive_after_gc()); |
| PrintF("\n\n"); |
| } |
| |
| isolate_->global_handles()->TearDown(); |
| |
| external_string_table_.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; |
| } |
| |
| store_buffer()->TearDown(); |
| incremental_marking()->TearDown(); |
| |
| isolate_->memory_allocator()->TearDown(); |
| |
| delete relocation_mutex_; |
| |
| #ifdef DEBUG |
| delete debug_utils_; |
| debug_utils_ = NULL; |
| #endif |
| } |
| |
| |
| void Heap::Shrink() { |
| // Try to shrink all paged spaces. |
| PagedSpaces spaces; |
| for (PagedSpace* space = spaces.next(); |
| space != NULL; |
| space = spaces.next()) { |
| space->ReleaseAllUnusedPages(); |
| } |
| } |
| |
| |
| 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; |
| isolate_->handle_scope_implementer()->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 UnreachableObjectsFilter : public HeapObjectsFilter { |
| public: |
| UnreachableObjectsFilter() { |
| MarkReachableObjects(); |
| } |
| |
| ~UnreachableObjectsFilter() { |
| Isolate::Current()->heap()->mark_compact_collector()->ClearMarkbits(); |
| } |
| |
| bool SkipObject(HeapObject* object) { |
| MarkBit mark_bit = Marking::MarkBitFrom(object); |
| return !mark_bit.Get(); |
| } |
| |
| private: |
| class MarkingVisitor : public ObjectVisitor { |
| public: |
| MarkingVisitor() : marking_stack_(10) {} |
| |
| void VisitPointers(Object** start, Object** end) { |
| for (Object** p = start; p < end; p++) { |
| if (!(*p)->IsHeapObject()) continue; |
| HeapObject* obj = HeapObject::cast(*p); |
| MarkBit mark_bit = Marking::MarkBitFrom(obj); |
| if (!mark_bit.Get()) { |
| mark_bit.Set(); |
| marking_stack_.Add(obj); |
| } |
| } |
| } |
| |
| void TransitiveClosure() { |
| while (!marking_stack_.is_empty()) { |
| HeapObject* obj = marking_stack_.RemoveLast(); |
| obj->Iterate(this); |
| } |
| } |
| |
| private: |
| List<HeapObject*> marking_stack_; |
| }; |
| |
| void MarkReachableObjects() { |
| Heap* heap = Isolate::Current()->heap(); |
| MarkingVisitor visitor; |
| heap->IterateRoots(&visitor, VISIT_ALL); |
| visitor.TransitiveClosure(); |
| } |
| |
| 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_ = new SpaceIterator; |
| switch (filtering_) { |
| 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; |
| Reset(); |
| |
| MarkVisitor mark_visitor(this); |
| MarkRecursively(root, &mark_visitor); |
| |
| UnmarkVisitor unmark_visitor(this); |
| UnmarkRecursively(root, &unmark_visitor); |
| |
| ProcessResults(); |
| } |
| |
| |
| static bool SafeIsGlobalContext(HeapObject* obj) { |
| return obj->map() == obj->GetHeap()->raw_unchecked_global_context_map(); |
| } |
| |
| |
| 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 = SafeIsGlobalContext(obj); |
| |
| // not visited yet |
| Map* map_p = reinterpret_cast<Map*>(HeapObject::cast(map)); |
| |
| Address map_addr = map_p->address(); |
| |
| obj->set_map_no_write_barrier(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_no_write_barrier(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 one |
| // given root object and finds a path to a specific heap object and |
| // prints it. |
| void Heap::TracePathToObjectFrom(Object* target, Object* root) { |
| PathTracer tracer(target, PathTracer::FIND_ALL, VISIT_ALL); |
| tracer.VisitPointer(&root); |
| } |
| |
| |
| // Triggers a depth-first traversal of reachable objects from roots |
| // and finds a path to a specific heap object and prints it. |
| void Heap::TracePathToObject(Object* target) { |
| PathTracer tracer(target, PathTracer::FIND_ALL, VISIT_ALL); |
| IterateRoots(&tracer, VISIT_ONLY_STRONG); |
| } |
| |
| |
| // Triggers a depth-first traversal of reachable objects from roots |
| // and finds a path to any global object and prints it. Useful for |
| // determining the source for leaks of global objects. |
| void Heap::TracePathToGlobal() { |
| PathTracer tracer(PathTracer::kAnyGlobalObject, |
| PathTracer::FIND_ALL, |
| VISIT_ALL); |
| IterateRoots(&tracer, VISIT_ONLY_STRONG); |
| } |
| #endif |
| |
| |
| 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->Available(); |
| } |
| return holes_size; |
| } |
| |
| |
| GCTracer::GCTracer(Heap* heap, |
| const char* gc_reason, |
| const char* collector_reason) |
| : start_time_(0.0), |
| start_object_size_(0), |
| start_memory_size_(0), |
| gc_count_(0), |
| full_gc_count_(0), |
| allocated_since_last_gc_(0), |
| spent_in_mutator_(0), |
| promoted_objects_size_(0), |
| heap_(heap), |
| gc_reason_(gc_reason), |
| collector_reason_(collector_reason) { |
| if (!FLAG_trace_gc && !FLAG_print_cumulative_gc_stat) return; |
| start_time_ = OS::TimeCurrentMillis(); |
| start_object_size_ = heap_->SizeOfObjects(); |
| start_memory_size_ = heap_->isolate()->memory_allocator()->Size(); |
| |
| 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() - heap_->alive_after_last_gc_; |
| |
| if (heap_->last_gc_end_timestamp_ > 0) { |
| spent_in_mutator_ = Max(start_time_ - heap_->last_gc_end_timestamp_, 0.0); |
| } |
| |
| steps_count_ = heap_->incremental_marking()->steps_count(); |
| steps_took_ = heap_->incremental_marking()->steps_took(); |
| longest_step_ = heap_->incremental_marking()->longest_step(); |
| steps_count_since_last_gc_ = |
| heap_->incremental_marking()->steps_count_since_last_gc(); |
| steps_took_since_last_gc_ = |
| heap_->incremental_marking()->steps_took_since_last_gc(); |
| } |
| |
| |
| GCTracer::~GCTracer() { |
| // Printf ONE line iff flag is set. |
| if (!FLAG_trace_gc && !FLAG_print_cumulative_gc_stat) return; |
| |
| bool first_gc = (heap_->last_gc_end_timestamp_ == 0); |
| |
| heap_->alive_after_last_gc_ = heap_->SizeOfObjects(); |
| heap_->last_gc_end_timestamp_ = OS::TimeCurrentMillis(); |
| |
| int time = static_cast<int>(heap_->last_gc_end_timestamp_ - start_time_); |
| |
| // Update cumulative GC statistics if required. |
| if (FLAG_print_cumulative_gc_stat) { |
| heap_->max_gc_pause_ = Max(heap_->max_gc_pause_, time); |
| heap_->max_alive_after_gc_ = Max(heap_->max_alive_after_gc_, |
| heap_->alive_after_last_gc_); |
| if (!first_gc) { |
| heap_->min_in_mutator_ = Min(heap_->min_in_mutator_, |
| static_cast<int>(spent_in_mutator_)); |
| } |
| } |
| |
| PrintPID("%8.0f ms: ", heap_->isolate()->time_millis_since_init()); |
| |
| if (!FLAG_trace_gc_nvp) { |
| int external_time = static_cast<int>(scopes_[Scope::EXTERNAL]); |
| |
| double end_memory_size_mb = |
| static_cast<double>(heap_->isolate()->memory_allocator()->Size()) / MB; |
| |
| PrintF("%s %.1f (%.1f) -> %.1f (%.1f) MB, ", |
| CollectorString(), |
| static_cast<double>(start_object_size_) / MB, |
| static_cast<double>(start_memory_size_) / MB, |
| SizeOfHeapObjects(), |
| end_memory_size_mb); |
| |
| if (external_time > 0) PrintF("%d / ", external_time); |
| PrintF("%d ms", time); |
| if (steps_count_ > 0) { |
| if (collector_ == SCAVENGER) { |
| PrintF(" (+ %d ms in %d steps since last GC)", |
| static_cast<int>(steps_took_since_last_gc_), |
| steps_count_since_last_gc_); |
| } else { |
| PrintF(" (+ %d ms in %d steps since start of marking, " |
| "biggest step %f ms)", |
| static_cast<int>(steps_took_), |
| steps_count_, |
| longest_step_); |
| } |
| } |
| |
| if (gc_reason_ != NULL) { |
| PrintF(" [%s]", gc_reason_); |
| } |
| |
| if (collector_reason_ != NULL) { |
| PrintF(" [%s]", collector_reason_); |
| } |
| |
| PrintF(".\n"); |
| } 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("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("evacuate=%d ", static_cast<int>(scopes_[Scope::MC_EVACUATE_PAGES])); |
| PrintF("new_new=%d ", |
| static_cast<int>(scopes_[Scope::MC_UPDATE_NEW_TO_NEW_POINTERS])); |
| PrintF("root_new=%d ", |
| static_cast<int>(scopes_[Scope::MC_UPDATE_ROOT_TO_NEW_POINTERS])); |
| PrintF("old_new=%d ", |
| static_cast<int>(scopes_[Scope::MC_UPDATE_OLD_TO_NEW_POINTERS])); |
| PrintF("compaction_ptrs=%d ", |
| static_cast<int>(scopes_[Scope::MC_UPDATE_POINTERS_TO_EVACUATED])); |
| PrintF("intracompaction_ptrs=%d ", static_cast<int>(scopes_[ |
| Scope::MC_UPDATE_POINTERS_BETWEEN_EVACUATED])); |
| PrintF("misc_compaction=%d ", |
| static_cast<int>(scopes_[Scope::MC_UPDATE_MISC_POINTERS])); |
| |
| PrintF("total_size_before=%" V8_PTR_PREFIX "d ", start_object_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_); |
| |
| if (collector_ == SCAVENGER) { |
| PrintF("stepscount=%d ", steps_count_since_last_gc_); |
| PrintF("stepstook=%d ", static_cast<int>(steps_took_since_last_gc_)); |
| } else { |
| PrintF("stepscount=%d ", steps_count_); |
| PrintF("stepstook=%d ", static_cast<int>(steps_took_)); |
| } |
| |
| PrintF("\n"); |
| } |
| |
| heap_->PrintShortHeapStatistics(); |
| } |
| |
| |
| const char* GCTracer::CollectorString() { |
| switch (collector_) { |
| case SCAVENGER: |
| return "Scavenge"; |
| case MARK_COMPACTOR: |
| return "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) & kHashMask); |
| for (int i = 0; i < kEntriesPerBucket; i++) { |
| Key& key = keys_[index + i]; |
| if ((key.map == map) && key.name->Equals(name)) { |
| return field_offsets_[index + i]; |
| } |
| } |
| return kNotFound; |
| } |
| |
| |
| void KeyedLookupCache::Update(Map* map, String* name, int field_offset) { |
| String* symbol; |
| if (HEAP->LookupSymbolIfExists(name, &symbol)) { |
| int index = (Hash(map, symbol) & kHashMask); |
| // After a GC there will be free slots, so we use them in order (this may |
| // help to get the most frequently used one in position 0). |
| for (int i = 0; i< kEntriesPerBucket; i++) { |
| Key& key = keys_[index]; |
| Object* free_entry_indicator = NULL; |
| if (key.map == free_entry_indicator) { |
| key.map = map; |
| key.name = symbol; |
| field_offsets_[index + i] = field_offset; |
| return; |
| } |
| } |
| // No free entry found in this bucket, so we move them all down one and |
| // put the new entry at position zero. |
| for (int i = kEntriesPerBucket - 1; i > 0; i--) { |
| Key& key = keys_[index + i]; |
| Key& key2 = keys_[index + i - 1]; |
| key = key2; |
| field_offsets_[index + i] = field_offsets_[index + i - 1]; |
| } |
| |
| // Write the new first entry. |
| Key& key = keys_[index]; |
| key.map = map; |
| key.name = symbol; |
| field_offsets_[index] = field_offset; |
| } |
| } |
| |
| |
| void KeyedLookupCache::Clear() { |
| for (int index = 0; index < kLength; index++) keys_[index].map = NULL; |
| } |
| |
| |
| void DescriptorLookupCache::Clear() { |
| for (int index = 0; index < kLength; index++) keys_[index].array = NULL; |
| } |
| |
| |
| #ifdef DEBUG |
| void Heap::GarbageCollectionGreedyCheck() { |
| ASSERT(FLAG_gc_greedy); |
| if (isolate_->bootstrapper()->IsActive()) return; |
| if (disallow_allocation_failure()) return; |
| CollectGarbage(NEW_SPACE); |
| } |
| #endif |
| |
| |
| TranscendentalCache::SubCache::SubCache(Type t) |
| : type_(t), |
| isolate_(Isolate::Current()) { |
| 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; |
| } |
| } |
| |
| |
| 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_the_hole_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_the_hole_value()) { |
| continue; |
| } |
| ASSERT(!heap_->InNewSpace(old_space_strings_[i])); |
| old_space_strings_[last++] = old_space_strings_[i]; |
| } |
| old_space_strings_.Rewind(last); |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| } |
| |
| |
| void ExternalStringTable::TearDown() { |
| new_space_strings_.Free(); |
| old_space_strings_.Free(); |
| } |
| |
| |
| void Heap::QueueMemoryChunkForFree(MemoryChunk* chunk) { |
| chunk->set_next_chunk(chunks_queued_for_free_); |
| chunks_queued_for_free_ = chunk; |
| } |
| |
| |
| void Heap::FreeQueuedChunks() { |
| if (chunks_queued_for_free_ == NULL) return; |
| MemoryChunk* next; |
| MemoryChunk* chunk; |
| for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) { |
| next = chunk->next_chunk(); |
| chunk->SetFlag(MemoryChunk::ABOUT_TO_BE_FREED); |
| |
| if (chunk->owner()->identity() == LO_SPACE) { |
| // StoreBuffer::Filter relies on MemoryChunk::FromAnyPointerAddress. |
| // If FromAnyPointerAddress encounters a slot that belongs to a large |
| // chunk queued for deletion it will fail to find the chunk because |
| // it try to perform a search in the list of pages owned by of the large |
| // object space and queued chunks were detached from that list. |
| // To work around this we split large chunk into normal kPageSize aligned |
| // pieces and initialize size, owner and flags field of every piece. |
| // If FromAnyPointerAddress encounters a slot that belongs to one of |
| // these smaller pieces it will treat it as a slot on a normal Page. |
| Address chunk_end = chunk->address() + chunk->size(); |
| MemoryChunk* inner = MemoryChunk::FromAddress( |
| chunk->address() + Page::kPageSize); |
| MemoryChunk* inner_last = MemoryChunk::FromAddress(chunk_end - 1); |
| while (inner <= inner_last) { |
| // Size of a large chunk is always a multiple of |
| // OS::AllocateAlignment() so there is always |
| // enough space for a fake MemoryChunk header. |
| Address area_end = Min(inner->address() + Page::kPageSize, chunk_end); |
| // Guard against overflow. |
| if (area_end < inner->address()) area_end = chunk_end; |
| inner->SetArea(inner->address(), area_end); |
| inner->set_size(Page::kPageSize); |
| inner->set_owner(lo_space()); |
| inner->SetFlag(MemoryChunk::ABOUT_TO_BE_FREED); |
| inner = MemoryChunk::FromAddress( |
| inner->address() + Page::kPageSize); |
| } |
| } |
| } |
| isolate_->heap()->store_buffer()->Compact(); |
| isolate_->heap()->store_buffer()->Filter(MemoryChunk::ABOUT_TO_BE_FREED); |
| for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) { |
| next = chunk->next_chunk(); |
| isolate_->memory_allocator()->Free(chunk); |
| } |
| chunks_queued_for_free_ = NULL; |
| } |
| |
| |
| void Heap::RememberUnmappedPage(Address page, bool compacted) { |
| uintptr_t p = reinterpret_cast<uintptr_t>(page); |
| // Tag the page pointer to make it findable in the dump file. |
| if (compacted) { |
| p ^= 0xc1ead & (Page::kPageSize - 1); // Cleared. |
| } else { |
| p ^= 0x1d1ed & (Page::kPageSize - 1); // I died. |
| } |
| remembered_unmapped_pages_[remembered_unmapped_pages_index_] = |
| reinterpret_cast<Address>(p); |
| remembered_unmapped_pages_index_++; |
| remembered_unmapped_pages_index_ %= kRememberedUnmappedPages; |
| } |
| |
| |
| void Heap::ClearObjectStats(bool clear_last_time_stats) { |
| memset(object_counts_, 0, sizeof(object_counts_)); |
| memset(object_sizes_, 0, sizeof(object_sizes_)); |
| if (clear_last_time_stats) { |
| memset(object_counts_last_time_, 0, sizeof(object_counts_last_time_)); |
| memset(object_sizes_last_time_, 0, sizeof(object_sizes_last_time_)); |
| } |
| } |
| |
| |
| static LazyMutex checkpoint_object_stats_mutex = LAZY_MUTEX_INITIALIZER; |
| |
| |
| void Heap::CheckpointObjectStats() { |
| ScopedLock lock(checkpoint_object_stats_mutex.Pointer()); |
| Counters* counters = isolate()->counters(); |
| #define ADJUST_LAST_TIME_OBJECT_COUNT(name) \ |
| counters->count_of_##name()->Increment( \ |
| static_cast<int>(object_counts_[name])); \ |
| counters->count_of_##name()->Decrement( \ |
| static_cast<int>(object_counts_last_time_[name])); \ |
| counters->size_of_##name()->Increment( \ |
| static_cast<int>(object_sizes_[name])); \ |
| counters->size_of_##name()->Decrement( \ |
| static_cast<int>(object_sizes_last_time_[name])); |
| INSTANCE_TYPE_LIST(ADJUST_LAST_TIME_OBJECT_COUNT) |
| #undef ADJUST_LAST_TIME_OBJECT_COUNT |
| int index; |
| #define ADJUST_LAST_TIME_OBJECT_COUNT(name) \ |
| index = FIRST_CODE_KIND_SUB_TYPE + Code::name; \ |
| counters->count_of_CODE_TYPE_##name()->Increment( \ |
| static_cast<int>(object_counts_[index])); \ |
| counters->count_of_CODE_TYPE_##name()->Decrement( \ |
| static_cast<int>(object_counts_last_time_[index])); \ |
| counters->size_of_CODE_TYPE_##name()->Increment( \ |
| static_cast<int>(object_sizes_[index])); \ |
| counters->size_of_CODE_TYPE_##name()->Decrement( \ |
| static_cast<int>(object_sizes_last_time_[index])); |
| CODE_KIND_LIST(ADJUST_LAST_TIME_OBJECT_COUNT) |
| #undef ADJUST_LAST_TIME_OBJECT_COUNT |
| #define ADJUST_LAST_TIME_OBJECT_COUNT(name) \ |
| index = FIRST_FIXED_ARRAY_SUB_TYPE + name; \ |
| counters->count_of_FIXED_ARRAY_##name()->Increment( \ |
| static_cast<int>(object_counts_[index])); \ |
| counters->count_of_FIXED_ARRAY_##name()->Decrement( \ |
| static_cast<int>(object_counts_last_time_[index])); \ |
| counters->size_of_FIXED_ARRAY_##name()->Increment( \ |
| static_cast<int>(object_sizes_[index])); \ |
| counters->size_of_FIXED_ARRAY_##name()->Decrement( \ |
| static_cast<int>(object_sizes_last_time_[index])); |
| FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(ADJUST_LAST_TIME_OBJECT_COUNT) |
| #undef ADJUST_LAST_TIME_OBJECT_COUNT |
| |
| memcpy(object_counts_last_time_, object_counts_, sizeof(object_counts_)); |
| memcpy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_)); |
| ClearObjectStats(); |
| } |
| |
| } } // namespace v8::internal |