| // Copyright 2009 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "v8.h" |
| |
| #include "accessors.h" |
| #include "api.h" |
| #include "bootstrapper.h" |
| #include "codegen-inl.h" |
| #include "compilation-cache.h" |
| #include "debug.h" |
| #include "heap-profiler.h" |
| #include "global-handles.h" |
| #include "mark-compact.h" |
| #include "natives.h" |
| #include "scanner.h" |
| #include "scopeinfo.h" |
| #include "v8threads.h" |
| #if V8_TARGET_ARCH_ARM && V8_NATIVE_REGEXP |
| #include "regexp-macro-assembler.h" |
| #endif |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| String* Heap::hidden_symbol_; |
| Object* Heap::roots_[Heap::kRootListLength]; |
| |
| |
| NewSpace Heap::new_space_; |
| OldSpace* Heap::old_pointer_space_ = NULL; |
| OldSpace* Heap::old_data_space_ = NULL; |
| OldSpace* Heap::code_space_ = NULL; |
| MapSpace* Heap::map_space_ = NULL; |
| CellSpace* Heap::cell_space_ = NULL; |
| LargeObjectSpace* Heap::lo_space_ = NULL; |
| |
| static const int kMinimumPromotionLimit = 2*MB; |
| static const int kMinimumAllocationLimit = 8*MB; |
| |
| int Heap::old_gen_promotion_limit_ = kMinimumPromotionLimit; |
| int Heap::old_gen_allocation_limit_ = kMinimumAllocationLimit; |
| |
| int Heap::old_gen_exhausted_ = false; |
| |
| int Heap::amount_of_external_allocated_memory_ = 0; |
| int Heap::amount_of_external_allocated_memory_at_last_global_gc_ = 0; |
| |
| // semispace_size_ should be a power of 2 and old_generation_size_ should be |
| // a multiple of Page::kPageSize. |
| #if defined(ANDROID) |
| int Heap::semispace_size_ = 512*KB; |
| int Heap::old_generation_size_ = 128*MB; |
| int Heap::initial_semispace_size_ = 128*KB; |
| #elif defined(V8_TARGET_ARCH_X64) |
| int Heap::semispace_size_ = 16*MB; |
| int Heap::old_generation_size_ = 1*GB; |
| int Heap::initial_semispace_size_ = 1*MB; |
| #else |
| int Heap::semispace_size_ = 8*MB; |
| int Heap::old_generation_size_ = 512*MB; |
| int Heap::initial_semispace_size_ = 512*KB; |
| #endif |
| |
| GCCallback Heap::global_gc_prologue_callback_ = NULL; |
| GCCallback Heap::global_gc_epilogue_callback_ = NULL; |
| |
| // Variables set based on semispace_size_ and old_generation_size_ in |
| // ConfigureHeap. |
| int Heap::young_generation_size_ = 0; // Will be 2 * semispace_size_. |
| int Heap::survived_since_last_expansion_ = 0; |
| int Heap::external_allocation_limit_ = 0; |
| |
| Heap::HeapState Heap::gc_state_ = NOT_IN_GC; |
| |
| int Heap::mc_count_ = 0; |
| int Heap::gc_count_ = 0; |
| |
| int Heap::always_allocate_scope_depth_ = 0; |
| bool Heap::context_disposed_pending_ = false; |
| |
| #ifdef DEBUG |
| bool Heap::allocation_allowed_ = true; |
| |
| int Heap::allocation_timeout_ = 0; |
| bool Heap::disallow_allocation_failure_ = false; |
| #endif // DEBUG |
| |
| |
| int 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(); |
| } |
| |
| |
| int 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; |
| } |
| |
| |
| GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space) { |
| // Is global GC requested? |
| if (space != NEW_SPACE || FLAG_gc_global) { |
| Counters::gc_compactor_caused_by_request.Increment(); |
| return MARK_COMPACTOR; |
| } |
| |
| // Is enough data promoted to justify a global GC? |
| if (OldGenerationPromotionLimitReached()) { |
| Counters::gc_compactor_caused_by_promoted_data.Increment(); |
| return MARK_COMPACTOR; |
| } |
| |
| // Have allocation in OLD and LO failed? |
| if (old_gen_exhausted_) { |
| Counters::gc_compactor_caused_by_oldspace_exhaustion.Increment(); |
| return MARK_COMPACTOR; |
| } |
| |
| // Is there enough space left in OLD to guarantee that a scavenge can |
| // succeed? |
| // |
| // Note that MemoryAllocator->MaxAvailable() undercounts the memory available |
| // for object promotion. It counts only the bytes that the memory |
| // allocator has not yet allocated from the OS and assigned to any space, |
| // and does not count available bytes already in the old space or code |
| // space. Undercounting is safe---we may get an unrequested full GC when |
| // a scavenge would have succeeded. |
| if (MemoryAllocator::MaxAvailable() <= new_space_.Size()) { |
| Counters::gc_compactor_caused_by_oldspace_exhaustion.Increment(); |
| return MARK_COMPACTOR; |
| } |
| |
| // Default |
| return SCAVENGER; |
| } |
| |
| |
| // TODO(1238405): Combine the infrastructure for --heap-stats and |
| // --log-gc to avoid the complicated preprocessor and flag testing. |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| void Heap::ReportStatisticsBeforeGC() { |
| // Heap::ReportHeapStatistics will also log NewSpace statistics when |
| // compiled with ENABLE_LOGGING_AND_PROFILING and --log-gc is set. The |
| // following logic is used to avoid double logging. |
| #if defined(DEBUG) && defined(ENABLE_LOGGING_AND_PROFILING) |
| if (FLAG_heap_stats || FLAG_log_gc) new_space_.CollectStatistics(); |
| if (FLAG_heap_stats) { |
| ReportHeapStatistics("Before GC"); |
| } else if (FLAG_log_gc) { |
| new_space_.ReportStatistics(); |
| } |
| if (FLAG_heap_stats || FLAG_log_gc) new_space_.ClearHistograms(); |
| #elif defined(DEBUG) |
| if (FLAG_heap_stats) { |
| new_space_.CollectStatistics(); |
| ReportHeapStatistics("Before GC"); |
| new_space_.ClearHistograms(); |
| } |
| #elif defined(ENABLE_LOGGING_AND_PROFILING) |
| if (FLAG_log_gc) { |
| new_space_.CollectStatistics(); |
| new_space_.ReportStatistics(); |
| new_space_.ClearHistograms(); |
| } |
| #endif |
| } |
| |
| |
| #if defined(ENABLE_LOGGING_AND_PROFILING) |
| void Heap::PrintShortHeapStatistics() { |
| if (!FLAG_trace_gc_verbose) return; |
| PrintF("Memory allocator, used: %8d, available: %8d\n", |
| MemoryAllocator::Size(), MemoryAllocator::Available()); |
| PrintF("New space, used: %8d, available: %8d\n", |
| Heap::new_space_.Size(), new_space_.Available()); |
| PrintF("Old pointers, used: %8d, available: %8d\n", |
| old_pointer_space_->Size(), old_pointer_space_->Available()); |
| PrintF("Old data space, used: %8d, available: %8d\n", |
| old_data_space_->Size(), old_data_space_->Available()); |
| PrintF("Code space, used: %8d, available: %8d\n", |
| code_space_->Size(), code_space_->Available()); |
| PrintF("Map space, used: %8d, available: %8d\n", |
| map_space_->Size(), map_space_->Available()); |
| PrintF("Large object space, used: %8d, avaialble: %8d\n", |
| lo_space_->Size(), lo_space_->Available()); |
| } |
| #endif |
| |
| |
| // TODO(1238405): Combine the infrastructure for --heap-stats and |
| // --log-gc to avoid the complicated preprocessor and flag testing. |
| void Heap::ReportStatisticsAfterGC() { |
| // Similar to the before GC, we use some complicated logic to ensure that |
| // NewSpace statistics are logged exactly once when --log-gc is turned on. |
| #if defined(DEBUG) && defined(ENABLE_LOGGING_AND_PROFILING) |
| if (FLAG_heap_stats) { |
| new_space_.CollectStatistics(); |
| ReportHeapStatistics("After GC"); |
| } else if (FLAG_log_gc) { |
| new_space_.ReportStatistics(); |
| } |
| #elif defined(DEBUG) |
| if (FLAG_heap_stats) ReportHeapStatistics("After GC"); |
| #elif defined(ENABLE_LOGGING_AND_PROFILING) |
| if (FLAG_log_gc) new_space_.ReportStatistics(); |
| #endif |
| } |
| #endif // defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| |
| |
| void Heap::GarbageCollectionPrologue() { |
| TranscendentalCache::Clear(); |
| gc_count_++; |
| #ifdef DEBUG |
| ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| allow_allocation(false); |
| |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| |
| if (FLAG_gc_verbose) Print(); |
| |
| if (FLAG_print_rset) { |
| // Not all spaces have remembered set bits that we care about. |
| old_pointer_space_->PrintRSet(); |
| map_space_->PrintRSet(); |
| lo_space_->PrintRSet(); |
| } |
| #endif |
| |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| ReportStatisticsBeforeGC(); |
| #endif |
| } |
| |
| int Heap::SizeOfObjects() { |
| int total = 0; |
| AllSpaces spaces; |
| while (Space* space = spaces.next()) { |
| total += space->Size(); |
| } |
| return total; |
| } |
| |
| void Heap::GarbageCollectionEpilogue() { |
| #ifdef DEBUG |
| allow_allocation(true); |
| ZapFromSpace(); |
| |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| |
| if (FLAG_print_global_handles) GlobalHandles::Print(); |
| if (FLAG_print_handles) PrintHandles(); |
| if (FLAG_gc_verbose) Print(); |
| if (FLAG_code_stats) ReportCodeStatistics("After GC"); |
| #endif |
| |
| Counters::alive_after_last_gc.Set(SizeOfObjects()); |
| |
| Counters::symbol_table_capacity.Set(symbol_table()->Capacity()); |
| Counters::number_of_symbols.Set(symbol_table()->NumberOfElements()); |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| ReportStatisticsAfterGC(); |
| #endif |
| #ifdef ENABLE_DEBUGGER_SUPPORT |
| Debug::AfterGarbageCollection(); |
| #endif |
| } |
| |
| |
| void Heap::CollectAllGarbage(bool force_compaction) { |
| // Since we are ignoring the return value, the exact choice of space does |
| // not matter, so long as we do not specify NEW_SPACE, which would not |
| // cause a full GC. |
| MarkCompactCollector::SetForceCompaction(force_compaction); |
| CollectGarbage(0, OLD_POINTER_SPACE); |
| MarkCompactCollector::SetForceCompaction(false); |
| } |
| |
| |
| void Heap::CollectAllGarbageIfContextDisposed() { |
| // If the garbage collector interface is exposed through the global |
| // gc() function, we avoid being clever about forcing GCs when |
| // contexts are disposed and leave it to the embedder to make |
| // informed decisions about when to force a collection. |
| if (!FLAG_expose_gc && context_disposed_pending_) { |
| HistogramTimerScope scope(&Counters::gc_context); |
| CollectAllGarbage(false); |
| } |
| context_disposed_pending_ = false; |
| } |
| |
| |
| void Heap::NotifyContextDisposed() { |
| context_disposed_pending_ = true; |
| } |
| |
| |
| bool Heap::CollectGarbage(int requested_size, AllocationSpace space) { |
| // The VM is in the GC state until exiting this function. |
| VMState state(GC); |
| |
| #ifdef DEBUG |
| // Reset the allocation timeout to the GC interval, but make sure to |
| // allow at least a few allocations after a collection. The reason |
| // for this is that we have a lot of allocation sequences and we |
| // assume that a garbage collection will allow the subsequent |
| // allocation attempts to go through. |
| allocation_timeout_ = Max(6, FLAG_gc_interval); |
| #endif |
| |
| { GCTracer tracer; |
| GarbageCollectionPrologue(); |
| // The GC count was incremented in the prologue. Tell the tracer about |
| // it. |
| tracer.set_gc_count(gc_count_); |
| |
| GarbageCollector collector = SelectGarbageCollector(space); |
| // Tell the tracer which collector we've selected. |
| tracer.set_collector(collector); |
| |
| HistogramTimer* rate = (collector == SCAVENGER) |
| ? &Counters::gc_scavenger |
| : &Counters::gc_compactor; |
| rate->Start(); |
| PerformGarbageCollection(space, collector, &tracer); |
| rate->Stop(); |
| |
| GarbageCollectionEpilogue(); |
| } |
| |
| |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| if (FLAG_log_gc) HeapProfiler::WriteSample(); |
| #endif |
| |
| switch (space) { |
| case NEW_SPACE: |
| return new_space_.Available() >= requested_size; |
| case OLD_POINTER_SPACE: |
| return old_pointer_space_->Available() >= requested_size; |
| case OLD_DATA_SPACE: |
| return old_data_space_->Available() >= requested_size; |
| case CODE_SPACE: |
| return code_space_->Available() >= requested_size; |
| case MAP_SPACE: |
| return map_space_->Available() >= requested_size; |
| case CELL_SPACE: |
| return cell_space_->Available() >= requested_size; |
| case LO_SPACE: |
| return lo_space_->Available() >= requested_size; |
| } |
| return false; |
| } |
| |
| |
| void Heap::PerformScavenge() { |
| GCTracer tracer; |
| PerformGarbageCollection(NEW_SPACE, SCAVENGER, &tracer); |
| } |
| |
| |
| #ifdef DEBUG |
| // Helper class for verifying the symbol table. |
| class SymbolTableVerifier : public ObjectVisitor { |
| public: |
| SymbolTableVerifier() { } |
| void VisitPointers(Object** start, Object** end) { |
| // Visit all HeapObject pointers in [start, end). |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) { |
| // Check that the symbol is actually a symbol. |
| ASSERT((*p)->IsNull() || (*p)->IsUndefined() || (*p)->IsSymbol()); |
| } |
| } |
| } |
| }; |
| #endif // DEBUG |
| |
| |
| static void VerifySymbolTable() { |
| #ifdef DEBUG |
| SymbolTableVerifier verifier; |
| Heap::symbol_table()->IterateElements(&verifier); |
| #endif // DEBUG |
| } |
| |
| |
| void Heap::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::PerformGarbageCollection(AllocationSpace space, |
| GarbageCollector collector, |
| GCTracer* tracer) { |
| VerifySymbolTable(); |
| if (collector == MARK_COMPACTOR && global_gc_prologue_callback_) { |
| ASSERT(!allocation_allowed_); |
| global_gc_prologue_callback_(); |
| } |
| EnsureFromSpaceIsCommitted(); |
| if (collector == MARK_COMPACTOR) { |
| MarkCompact(tracer); |
| |
| int old_gen_size = PromotedSpaceSize(); |
| old_gen_promotion_limit_ = |
| old_gen_size + Max(kMinimumPromotionLimit, old_gen_size / 3); |
| old_gen_allocation_limit_ = |
| old_gen_size + Max(kMinimumAllocationLimit, old_gen_size / 2); |
| old_gen_exhausted_ = false; |
| } |
| Scavenge(); |
| |
| Counters::objs_since_last_young.Set(0); |
| |
| 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_; |
| } |
| |
| if (collector == MARK_COMPACTOR && global_gc_epilogue_callback_) { |
| ASSERT(!allocation_allowed_); |
| global_gc_epilogue_callback_(); |
| } |
| VerifySymbolTable(); |
| } |
| |
| |
| void Heap::PostGarbageCollectionProcessing() { |
| // Process weak handles post gc. |
| { |
| DisableAssertNoAllocation allow_allocation; |
| GlobalHandles::PostGarbageCollectionProcessing(); |
| } |
| // Update flat string readers. |
| FlatStringReader::PostGarbageCollectionProcessing(); |
| } |
| |
| |
| void Heap::MarkCompact(GCTracer* tracer) { |
| gc_state_ = MARK_COMPACT; |
| mc_count_++; |
| tracer->set_full_gc_count(mc_count_); |
| LOG(ResourceEvent("markcompact", "begin")); |
| |
| MarkCompactCollector::Prepare(tracer); |
| |
| bool is_compacting = MarkCompactCollector::IsCompacting(); |
| |
| MarkCompactPrologue(is_compacting); |
| |
| MarkCompactCollector::CollectGarbage(); |
| |
| MarkCompactEpilogue(is_compacting); |
| |
| LOG(ResourceEvent("markcompact", "end")); |
| |
| gc_state_ = NOT_IN_GC; |
| |
| Shrink(); |
| |
| Counters::objs_since_last_full.Set(0); |
| context_disposed_pending_ = false; |
| } |
| |
| |
| void Heap::MarkCompactPrologue(bool is_compacting) { |
| // At any old GC clear the keyed lookup cache to enable collection of unused |
| // maps. |
| KeyedLookupCache::Clear(); |
| ContextSlotCache::Clear(); |
| DescriptorLookupCache::Clear(); |
| |
| CompilationCache::MarkCompactPrologue(); |
| |
| Top::MarkCompactPrologue(is_compacting); |
| ThreadManager::MarkCompactPrologue(is_compacting); |
| } |
| |
| |
| void Heap::MarkCompactEpilogue(bool is_compacting) { |
| Top::MarkCompactEpilogue(is_compacting); |
| ThreadManager::MarkCompactEpilogue(is_compacting); |
| } |
| |
| |
| Object* Heap::FindCodeObject(Address a) { |
| Object* obj = code_space_->FindObject(a); |
| if (obj->IsFailure()) { |
| obj = lo_space_->FindObject(a); |
| } |
| ASSERT(!obj->IsFailure()); |
| return obj; |
| } |
| |
| |
| // Helper class for copying HeapObjects |
| class ScavengeVisitor: public ObjectVisitor { |
| public: |
| |
| void VisitPointer(Object** p) { ScavengePointer(p); } |
| |
| void VisitPointers(Object** start, Object** end) { |
| // Copy all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) ScavengePointer(p); |
| } |
| |
| private: |
| void ScavengePointer(Object** p) { |
| Object* object = *p; |
| if (!Heap::InNewSpace(object)) return; |
| Heap::ScavengeObject(reinterpret_cast<HeapObject**>(p), |
| reinterpret_cast<HeapObject*>(object)); |
| } |
| }; |
| |
| |
| // A queue of pointers and maps of to-be-promoted objects during a |
| // scavenge collection. |
| class PromotionQueue { |
| public: |
| void Initialize(Address start_address) { |
| front_ = rear_ = reinterpret_cast<HeapObject**>(start_address); |
| } |
| |
| bool is_empty() { return front_ <= rear_; } |
| |
| void insert(HeapObject* object, Map* map) { |
| *(--rear_) = object; |
| *(--rear_) = map; |
| // Assert no overflow into live objects. |
| ASSERT(reinterpret_cast<Address>(rear_) >= Heap::new_space()->top()); |
| } |
| |
| void remove(HeapObject** object, Map** map) { |
| *object = *(--front_); |
| *map = Map::cast(*(--front_)); |
| // Assert no underflow. |
| ASSERT(front_ >= rear_); |
| } |
| |
| private: |
| // The front of the queue is higher in memory than the rear. |
| HeapObject** front_; |
| HeapObject** rear_; |
| }; |
| |
| |
| // Shared state read by the scavenge collector and set by ScavengeObject. |
| static PromotionQueue promotion_queue; |
| |
| |
| #ifdef DEBUG |
| // Visitor class to verify pointers in code or data space do not point into |
| // new space. |
| class VerifyNonPointerSpacePointersVisitor: public ObjectVisitor { |
| public: |
| void VisitPointers(Object** start, Object**end) { |
| for (Object** current = start; current < end; current++) { |
| if ((*current)->IsHeapObject()) { |
| ASSERT(!Heap::InNewSpace(HeapObject::cast(*current))); |
| } |
| } |
| } |
| }; |
| |
| |
| static void VerifyNonPointerSpacePointers() { |
| // Verify that there are no pointers to new space in spaces where we |
| // do not expect them. |
| VerifyNonPointerSpacePointersVisitor v; |
| HeapObjectIterator code_it(Heap::code_space()); |
| while (code_it.has_next()) { |
| HeapObject* object = code_it.next(); |
| object->Iterate(&v); |
| } |
| |
| HeapObjectIterator data_it(Heap::old_data_space()); |
| while (data_it.has_next()) data_it.next()->Iterate(&v); |
| } |
| #endif |
| |
| |
| void Heap::Scavenge() { |
| #ifdef DEBUG |
| if (FLAG_enable_slow_asserts) VerifyNonPointerSpacePointers(); |
| #endif |
| |
| gc_state_ = SCAVENGE; |
| |
| // Implements Cheney's copying algorithm |
| LOG(ResourceEvent("scavenge", "begin")); |
| |
| // Clear descriptor cache. |
| DescriptorLookupCache::Clear(); |
| |
| // Used for updating survived_since_last_expansion_ at function end. |
| int survived_watermark = PromotedSpaceSize(); |
| |
| if (new_space_.Capacity() < new_space_.MaximumCapacity() && |
| survived_since_last_expansion_ > new_space_.Capacity()) { |
| // Grow the size of new space if there is room to grow and enough |
| // data has survived scavenge since the last expansion. |
| new_space_.Grow(); |
| survived_since_last_expansion_ = 0; |
| } |
| |
| // Flip the semispaces. After flipping, to space is empty, from space has |
| // live objects. |
| new_space_.Flip(); |
| new_space_.ResetAllocationInfo(); |
| |
| // We need to sweep newly copied objects which can be either in the |
| // to space or promoted to the old generation. For to-space |
| // objects, we treat the bottom of the to space as a queue. Newly |
| // copied and unswept objects lie between a 'front' mark and the |
| // allocation pointer. |
| // |
| // Promoted objects can go into various old-generation spaces, and |
| // can be allocated internally in the spaces (from the free list). |
| // We treat the top of the to space as a queue of addresses of |
| // promoted objects. The addresses of newly promoted and unswept |
| // objects lie between a 'front' mark and a 'rear' mark that is |
| // updated as a side effect of promoting an object. |
| // |
| // There is guaranteed to be enough room at the top of the to space |
| // for the addresses of promoted objects: every object promoted |
| // frees up its size in bytes from the top of the new space, and |
| // objects are at least one pointer in size. |
| Address new_space_front = new_space_.ToSpaceLow(); |
| promotion_queue.Initialize(new_space_.ToSpaceHigh()); |
| |
| ScavengeVisitor scavenge_visitor; |
| // Copy roots. |
| IterateRoots(&scavenge_visitor); |
| |
| // Copy objects reachable from weak pointers. |
| GlobalHandles::IterateWeakRoots(&scavenge_visitor); |
| |
| // Copy objects reachable from the old generation. By definition, |
| // there are no intergenerational pointers in code or data spaces. |
| IterateRSet(old_pointer_space_, &ScavengePointer); |
| IterateRSet(map_space_, &ScavengePointer); |
| lo_space_->IterateRSet(&ScavengePointer); |
| |
| // Copy objects reachable from cells by scavenging cell values directly. |
| HeapObjectIterator cell_iterator(cell_space_); |
| while (cell_iterator.has_next()) { |
| HeapObject* 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)); |
| } |
| } |
| |
| do { |
| ASSERT(new_space_front <= new_space_.top()); |
| |
| // The addresses new_space_front and new_space_.top() define a |
| // queue of unprocessed copied objects. Process them until the |
| // queue is empty. |
| while (new_space_front < new_space_.top()) { |
| HeapObject* object = HeapObject::FromAddress(new_space_front); |
| object->Iterate(&scavenge_visitor); |
| new_space_front += object->Size(); |
| } |
| |
| // Promote and process all the to-be-promoted objects. |
| while (!promotion_queue.is_empty()) { |
| HeapObject* source; |
| Map* map; |
| promotion_queue.remove(&source, &map); |
| // Copy the from-space object to its new location (given by the |
| // forwarding address) and fix its map. |
| HeapObject* target = source->map_word().ToForwardingAddress(); |
| CopyBlock(reinterpret_cast<Object**>(target->address()), |
| reinterpret_cast<Object**>(source->address()), |
| source->SizeFromMap(map)); |
| target->set_map(map); |
| |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| // Update NewSpace stats if necessary. |
| RecordCopiedObject(target); |
| #endif |
| // Visit the newly copied object for pointers to new space. |
| target->Iterate(&scavenge_visitor); |
| UpdateRSet(target); |
| } |
| |
| // 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()); |
| |
| // Set age mark. |
| new_space_.set_age_mark(new_space_.top()); |
| |
| // Update how much has survived scavenge. |
| survived_since_last_expansion_ += |
| (PromotedSpaceSize() - survived_watermark) + new_space_.Size(); |
| |
| LOG(ResourceEvent("scavenge", "end")); |
| |
| gc_state_ = NOT_IN_GC; |
| } |
| |
| |
| void Heap::ClearRSetRange(Address start, int size_in_bytes) { |
| uint32_t start_bit; |
| Address start_word_address = |
| Page::ComputeRSetBitPosition(start, 0, &start_bit); |
| uint32_t end_bit; |
| Address end_word_address = |
| Page::ComputeRSetBitPosition(start + size_in_bytes - kIntSize, |
| 0, |
| &end_bit); |
| |
| // We want to clear the bits in the starting word starting with the |
| // first bit, and in the ending word up to and including the last |
| // bit. Build a pair of bitmasks to do that. |
| uint32_t start_bitmask = start_bit - 1; |
| uint32_t end_bitmask = ~((end_bit << 1) - 1); |
| |
| // If the start address and end address are the same, we mask that |
| // word once, otherwise mask the starting and ending word |
| // separately and all the ones in between. |
| if (start_word_address == end_word_address) { |
| Memory::uint32_at(start_word_address) &= (start_bitmask | end_bitmask); |
| } else { |
| Memory::uint32_at(start_word_address) &= start_bitmask; |
| Memory::uint32_at(end_word_address) &= end_bitmask; |
| start_word_address += kIntSize; |
| memset(start_word_address, 0, end_word_address - start_word_address); |
| } |
| } |
| |
| |
| class UpdateRSetVisitor: public ObjectVisitor { |
| public: |
| |
| void VisitPointer(Object** p) { |
| UpdateRSet(p); |
| } |
| |
| void VisitPointers(Object** start, Object** end) { |
| // Update a store into slots [start, end), used (a) to update remembered |
| // set when promoting a young object to old space or (b) to rebuild |
| // remembered sets after a mark-compact collection. |
| for (Object** p = start; p < end; p++) UpdateRSet(p); |
| } |
| private: |
| |
| void UpdateRSet(Object** p) { |
| // The remembered set should not be set. It should be clear for objects |
| // newly copied to old space, and it is cleared before rebuilding in the |
| // mark-compact collector. |
| ASSERT(!Page::IsRSetSet(reinterpret_cast<Address>(p), 0)); |
| if (Heap::InNewSpace(*p)) { |
| Page::SetRSet(reinterpret_cast<Address>(p), 0); |
| } |
| } |
| }; |
| |
| |
| int Heap::UpdateRSet(HeapObject* obj) { |
| ASSERT(!InNewSpace(obj)); |
| // Special handling of fixed arrays to iterate the body based on the start |
| // address and offset. Just iterating the pointers as in UpdateRSetVisitor |
| // will not work because Page::SetRSet needs to have the start of the |
| // object for large object pages. |
| if (obj->IsFixedArray()) { |
| FixedArray* array = FixedArray::cast(obj); |
| int length = array->length(); |
| for (int i = 0; i < length; i++) { |
| int offset = FixedArray::kHeaderSize + i * kPointerSize; |
| ASSERT(!Page::IsRSetSet(obj->address(), offset)); |
| if (Heap::InNewSpace(array->get(i))) { |
| Page::SetRSet(obj->address(), offset); |
| } |
| } |
| } else if (!obj->IsCode()) { |
| // Skip code object, we know it does not contain inter-generational |
| // pointers. |
| UpdateRSetVisitor v; |
| obj->Iterate(&v); |
| } |
| return obj->Size(); |
| } |
| |
| |
| void Heap::RebuildRSets() { |
| // By definition, we do not care about remembered set bits in code, |
| // data, or cell spaces. |
| map_space_->ClearRSet(); |
| RebuildRSets(map_space_); |
| |
| old_pointer_space_->ClearRSet(); |
| RebuildRSets(old_pointer_space_); |
| |
| Heap::lo_space_->ClearRSet(); |
| RebuildRSets(lo_space_); |
| } |
| |
| |
| void Heap::RebuildRSets(PagedSpace* space) { |
| HeapObjectIterator it(space); |
| while (it.has_next()) Heap::UpdateRSet(it.next()); |
| } |
| |
| |
| void Heap::RebuildRSets(LargeObjectSpace* space) { |
| LargeObjectIterator it(space); |
| while (it.has_next()) Heap::UpdateRSet(it.next()); |
| } |
| |
| |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| void Heap::RecordCopiedObject(HeapObject* obj) { |
| bool should_record = false; |
| #ifdef DEBUG |
| should_record = FLAG_heap_stats; |
| #endif |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| should_record = should_record || FLAG_log_gc; |
| #endif |
| if (should_record) { |
| if (new_space_.Contains(obj)) { |
| new_space_.RecordAllocation(obj); |
| } else { |
| new_space_.RecordPromotion(obj); |
| } |
| } |
| } |
| #endif // defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| |
| |
| |
| HeapObject* Heap::MigrateObject(HeapObject* source, |
| HeapObject* target, |
| int size) { |
| // Copy the content of source to target. |
| CopyBlock(reinterpret_cast<Object**>(target->address()), |
| reinterpret_cast<Object**>(source->address()), |
| size); |
| |
| // Set the forwarding address. |
| source->set_map_word(MapWord::FromForwardingAddress(target)); |
| |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| // Update NewSpace stats if necessary. |
| RecordCopiedObject(target); |
| #endif |
| |
| return target; |
| } |
| |
| |
| static inline bool IsShortcutCandidate(HeapObject* object, Map* map) { |
| STATIC_ASSERT(kNotStringTag != 0 && kSymbolTag != 0); |
| ASSERT(object->map() == map); |
| InstanceType type = map->instance_type(); |
| if ((type & kShortcutTypeMask) != kShortcutTypeTag) return false; |
| ASSERT(object->IsString() && !object->IsSymbol()); |
| return ConsString::cast(object)->unchecked_second() == Heap::empty_string(); |
| } |
| |
| |
| void Heap::ScavengeObjectSlow(HeapObject** p, HeapObject* object) { |
| ASSERT(InFromSpace(object)); |
| MapWord first_word = object->map_word(); |
| ASSERT(!first_word.IsForwardingAddress()); |
| |
| // Optimization: Bypass flattened ConsString objects. |
| if (IsShortcutCandidate(object, first_word.ToMap())) { |
| object = HeapObject::cast(ConsString::cast(object)->unchecked_first()); |
| *p = object; |
| // After patching *p we have to repeat the checks that object is in the |
| // active semispace of the young generation and not already copied. |
| if (!InNewSpace(object)) return; |
| first_word = object->map_word(); |
| if (first_word.IsForwardingAddress()) { |
| *p = first_word.ToForwardingAddress(); |
| return; |
| } |
| } |
| |
| int object_size = object->SizeFromMap(first_word.ToMap()); |
| // We rely on live objects in new space to be at least two pointers, |
| // so we can store the from-space address and map pointer of promoted |
| // objects in the to space. |
| ASSERT(object_size >= 2 * kPointerSize); |
| |
| // If the object should be promoted, we try to copy it to old space. |
| if (ShouldBePromoted(object->address(), object_size)) { |
| Object* result; |
| if (object_size > MaxObjectSizeInPagedSpace()) { |
| result = lo_space_->AllocateRawFixedArray(object_size); |
| if (!result->IsFailure()) { |
| // Save the from-space object pointer and its map pointer at the |
| // top of the to space to be swept and copied later. Write the |
| // forwarding address over the map word of the from-space |
| // object. |
| HeapObject* target = HeapObject::cast(result); |
| promotion_queue.insert(object, first_word.ToMap()); |
| object->set_map_word(MapWord::FromForwardingAddress(target)); |
| |
| // Give the space allocated for the result a proper map by |
| // treating it as a free list node (not linked into the free |
| // list). |
| FreeListNode* node = FreeListNode::FromAddress(target->address()); |
| node->set_size(object_size); |
| |
| *p = target; |
| return; |
| } |
| } else { |
| OldSpace* target_space = Heap::TargetSpace(object); |
| ASSERT(target_space == Heap::old_pointer_space_ || |
| target_space == Heap::old_data_space_); |
| result = target_space->AllocateRaw(object_size); |
| if (!result->IsFailure()) { |
| HeapObject* target = HeapObject::cast(result); |
| if (target_space == Heap::old_pointer_space_) { |
| // Save the from-space object pointer and its map pointer at the |
| // top of the to space to be swept and copied later. Write the |
| // forwarding address over the map word of the from-space |
| // object. |
| promotion_queue.insert(object, first_word.ToMap()); |
| object->set_map_word(MapWord::FromForwardingAddress(target)); |
| |
| // Give the space allocated for the result a proper map by |
| // treating it as a free list node (not linked into the free |
| // list). |
| FreeListNode* node = FreeListNode::FromAddress(target->address()); |
| node->set_size(object_size); |
| |
| *p = target; |
| } else { |
| // Objects promoted to the data space can be copied immediately |
| // and not revisited---we will never sweep that space for |
| // pointers and the copied objects do not contain pointers to |
| // new space objects. |
| *p = MigrateObject(object, target, object_size); |
| #ifdef DEBUG |
| VerifyNonPointerSpacePointersVisitor v; |
| (*p)->Iterate(&v); |
| #endif |
| } |
| return; |
| } |
| } |
| } |
| // The object should remain in new space or the old space allocation failed. |
| Object* result = new_space_.AllocateRaw(object_size); |
| // Failed allocation at this point is utterly unexpected. |
| ASSERT(!result->IsFailure()); |
| *p = MigrateObject(object, HeapObject::cast(result), object_size); |
| } |
| |
| |
| void Heap::ScavengePointer(HeapObject** p) { |
| ScavengeObject(p, *p); |
| } |
| |
| |
| Object* Heap::AllocatePartialMap(InstanceType instance_type, |
| int instance_size) { |
| Object* result = AllocateRawMap(); |
| if (result->IsFailure()) return 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_inobject_properties(0); |
| reinterpret_cast<Map*>(result)->set_unused_property_fields(0); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateMap(InstanceType instance_type, int instance_size) { |
| Object* result = AllocateRawMap(); |
| if (result->IsFailure()) return result; |
| |
| Map* map = reinterpret_cast<Map*>(result); |
| map->set_map(meta_map()); |
| map->set_instance_type(instance_type); |
| map->set_prototype(null_value()); |
| map->set_constructor(null_value()); |
| map->set_instance_size(instance_size); |
| map->set_inobject_properties(0); |
| map->set_pre_allocated_property_fields(0); |
| map->set_instance_descriptors(empty_descriptor_array()); |
| map->set_code_cache(empty_fixed_array()); |
| map->set_unused_property_fields(0); |
| map->set_bit_field(0); |
| map->set_bit_field2(0); |
| return map; |
| } |
| |
| |
| 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 = AllocatePartialMap(MAP_TYPE, Map::kSize); |
| if (obj->IsFailure()) 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); |
| |
| obj = AllocatePartialMap(FIXED_ARRAY_TYPE, FixedArray::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| set_fixed_array_map(Map::cast(obj)); |
| |
| obj = AllocatePartialMap(ODDBALL_TYPE, Oddball::kSize); |
| if (obj->IsFailure()) return false; |
| set_oddball_map(Map::cast(obj)); |
| |
| // Allocate the empty array |
| obj = AllocateEmptyFixedArray(); |
| if (obj->IsFailure()) return false; |
| set_empty_fixed_array(FixedArray::cast(obj)); |
| |
| obj = Allocate(oddball_map(), OLD_DATA_SPACE); |
| if (obj->IsFailure()) return false; |
| set_null_value(obj); |
| |
| // Allocate the empty descriptor array. |
| obj = AllocateEmptyFixedArray(); |
| if (obj->IsFailure()) return false; |
| set_empty_descriptor_array(DescriptorArray::cast(obj)); |
| |
| // Fix the instance_descriptors for the existing maps. |
| meta_map()->set_instance_descriptors(empty_descriptor_array()); |
| meta_map()->set_code_cache(empty_fixed_array()); |
| |
| fixed_array_map()->set_instance_descriptors(empty_descriptor_array()); |
| fixed_array_map()->set_code_cache(empty_fixed_array()); |
| |
| oddball_map()->set_instance_descriptors(empty_descriptor_array()); |
| oddball_map()->set_code_cache(empty_fixed_array()); |
| |
| // Fix prototype object for existing maps. |
| meta_map()->set_prototype(null_value()); |
| meta_map()->set_constructor(null_value()); |
| |
| fixed_array_map()->set_prototype(null_value()); |
| fixed_array_map()->set_constructor(null_value()); |
| |
| oddball_map()->set_prototype(null_value()); |
| oddball_map()->set_constructor(null_value()); |
| |
| obj = AllocateMap(HEAP_NUMBER_TYPE, HeapNumber::kSize); |
| if (obj->IsFailure()) return false; |
| set_heap_number_map(Map::cast(obj)); |
| |
| obj = AllocateMap(PROXY_TYPE, Proxy::kSize); |
| if (obj->IsFailure()) return false; |
| set_proxy_map(Map::cast(obj)); |
| |
| for (unsigned i = 0; i < ARRAY_SIZE(string_type_table); i++) { |
| const StringTypeTable& entry = string_type_table[i]; |
| obj = AllocateMap(entry.type, entry.size); |
| if (obj->IsFailure()) return false; |
| roots_[entry.index] = Map::cast(obj); |
| } |
| |
| obj = AllocateMap(SHORT_STRING_TYPE, SeqTwoByteString::kAlignedSize); |
| if (obj->IsFailure()) return false; |
| set_undetectable_short_string_map(Map::cast(obj)); |
| Map::cast(obj)->set_is_undetectable(); |
| |
| obj = AllocateMap(MEDIUM_STRING_TYPE, SeqTwoByteString::kAlignedSize); |
| if (obj->IsFailure()) return false; |
| set_undetectable_medium_string_map(Map::cast(obj)); |
| Map::cast(obj)->set_is_undetectable(); |
| |
| obj = AllocateMap(LONG_STRING_TYPE, SeqTwoByteString::kAlignedSize); |
| if (obj->IsFailure()) return false; |
| set_undetectable_long_string_map(Map::cast(obj)); |
| Map::cast(obj)->set_is_undetectable(); |
| |
| obj = AllocateMap(SHORT_ASCII_STRING_TYPE, SeqAsciiString::kAlignedSize); |
| if (obj->IsFailure()) return false; |
| set_undetectable_short_ascii_string_map(Map::cast(obj)); |
| Map::cast(obj)->set_is_undetectable(); |
| |
| obj = AllocateMap(MEDIUM_ASCII_STRING_TYPE, SeqAsciiString::kAlignedSize); |
| if (obj->IsFailure()) return false; |
| set_undetectable_medium_ascii_string_map(Map::cast(obj)); |
| Map::cast(obj)->set_is_undetectable(); |
| |
| obj = AllocateMap(LONG_ASCII_STRING_TYPE, SeqAsciiString::kAlignedSize); |
| if (obj->IsFailure()) return false; |
| set_undetectable_long_ascii_string_map(Map::cast(obj)); |
| Map::cast(obj)->set_is_undetectable(); |
| |
| obj = AllocateMap(BYTE_ARRAY_TYPE, ByteArray::kAlignedSize); |
| if (obj->IsFailure()) return false; |
| set_byte_array_map(Map::cast(obj)); |
| |
| obj = AllocateMap(PIXEL_ARRAY_TYPE, PixelArray::kAlignedSize); |
| if (obj->IsFailure()) return false; |
| set_pixel_array_map(Map::cast(obj)); |
| |
| obj = AllocateMap(CODE_TYPE, Code::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| set_code_map(Map::cast(obj)); |
| |
| obj = AllocateMap(JS_GLOBAL_PROPERTY_CELL_TYPE, |
| JSGlobalPropertyCell::kSize); |
| if (obj->IsFailure()) return false; |
| set_global_property_cell_map(Map::cast(obj)); |
| |
| obj = AllocateMap(FILLER_TYPE, kPointerSize); |
| if (obj->IsFailure()) return false; |
| set_one_pointer_filler_map(Map::cast(obj)); |
| |
| obj = AllocateMap(FILLER_TYPE, 2 * kPointerSize); |
| if (obj->IsFailure()) 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]; |
| obj = AllocateMap(entry.type, entry.size); |
| if (obj->IsFailure()) return false; |
| roots_[entry.index] = Map::cast(obj); |
| } |
| |
| obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| set_hash_table_map(Map::cast(obj)); |
| |
| obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| set_context_map(Map::cast(obj)); |
| |
| obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| set_catch_context_map(Map::cast(obj)); |
| |
| obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| set_global_context_map(Map::cast(obj)); |
| |
| obj = AllocateMap(JS_FUNCTION_TYPE, JSFunction::kSize); |
| if (obj->IsFailure()) return false; |
| set_boilerplate_function_map(Map::cast(obj)); |
| |
| obj = AllocateMap(SHARED_FUNCTION_INFO_TYPE, SharedFunctionInfo::kSize); |
| if (obj->IsFailure()) return false; |
| set_shared_function_info_map(Map::cast(obj)); |
| |
| ASSERT(!Heap::InNewSpace(Heap::empty_fixed_array())); |
| return true; |
| } |
| |
| |
| Object* Heap::AllocateHeapNumber(double value, PretenureFlag pretenure) { |
| // Statically ensure that it is safe to allocate heap numbers in paged |
| // spaces. |
| STATIC_ASSERT(HeapNumber::kSize <= Page::kMaxHeapObjectSize); |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| Object* result = AllocateRaw(HeapNumber::kSize, space, OLD_DATA_SPACE); |
| if (result->IsFailure()) return result; |
| |
| HeapObject::cast(result)->set_map(heap_number_map()); |
| HeapNumber::cast(result)->set_value(value); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateHeapNumber(double value) { |
| // Use general version, if we're forced to always allocate. |
| if (always_allocate()) return AllocateHeapNumber(value, NOT_TENURED); |
| // This version of AllocateHeapNumber is optimized for |
| // allocation in new space. |
| STATIC_ASSERT(HeapNumber::kSize <= Page::kMaxHeapObjectSize); |
| ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| Object* result = new_space_.AllocateRaw(HeapNumber::kSize); |
| if (result->IsFailure()) return result; |
| HeapObject::cast(result)->set_map(heap_number_map()); |
| HeapNumber::cast(result)->set_value(value); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateJSGlobalPropertyCell(Object* value) { |
| Object* result = AllocateRawCell(); |
| if (result->IsFailure()) return result; |
| HeapObject::cast(result)->set_map(global_property_cell_map()); |
| JSGlobalPropertyCell::cast(result)->set_value(value); |
| return result; |
| } |
| |
| |
| Object* Heap::CreateOddball(Map* map, |
| const char* to_string, |
| Object* to_number) { |
| Object* result = Allocate(map, OLD_DATA_SPACE); |
| if (result->IsFailure()) return result; |
| return Oddball::cast(result)->Initialize(to_string, to_number); |
| } |
| |
| |
| bool Heap::CreateApiObjects() { |
| Object* obj; |
| |
| obj = AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| set_neander_map(Map::cast(obj)); |
| |
| obj = Heap::AllocateJSObjectFromMap(neander_map()); |
| if (obj->IsFailure()) return false; |
| Object* elements = AllocateFixedArray(2); |
| if (elements->IsFailure()) return false; |
| FixedArray::cast(elements)->set(0, Smi::FromInt(0)); |
| JSObject::cast(obj)->set_elements(FixedArray::cast(elements)); |
| set_message_listeners(JSObject::cast(obj)); |
| |
| return true; |
| } |
| |
| |
| void Heap::CreateCEntryStub() { |
| CEntryStub stub(1); |
| set_c_entry_code(*stub.GetCode()); |
| } |
| |
| |
| #if V8_TARGET_ARCH_ARM && V8_NATIVE_REGEXP |
| void Heap::CreateRegExpCEntryStub() { |
| RegExpCEntryStub stub; |
| set_re_c_entry_code(*stub.GetCode()); |
| } |
| #endif |
| |
| |
| void Heap::CreateCEntryDebugBreakStub() { |
| CEntryDebugBreakStub stub; |
| set_c_entry_debug_break_code(*stub.GetCode()); |
| } |
| |
| |
| 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: |
| // { CEntryStub stub; |
| // c_entry_code_ = *stub.GetCode(); |
| // } |
| // { CEntryDebugBreakStub stub; |
| // c_entry_debug_break_code_ = *stub.GetCode(); |
| // } |
| // To workaround the problem, make separate functions without inlining. |
| Heap::CreateCEntryStub(); |
| Heap::CreateCEntryDebugBreakStub(); |
| Heap::CreateJSEntryStub(); |
| Heap::CreateJSConstructEntryStub(); |
| #if V8_TARGET_ARCH_ARM && V8_NATIVE_REGEXP |
| Heap::CreateRegExpCEntryStub(); |
| #endif |
| } |
| |
| |
| bool Heap::CreateInitialObjects() { |
| Object* obj; |
| |
| // The -0 value must be set before NumberFromDouble works. |
| obj = AllocateHeapNumber(-0.0, TENURED); |
| if (obj->IsFailure()) return false; |
| set_minus_zero_value(obj); |
| ASSERT(signbit(minus_zero_value()->Number()) != 0); |
| |
| obj = AllocateHeapNumber(OS::nan_value(), TENURED); |
| if (obj->IsFailure()) return false; |
| set_nan_value(obj); |
| |
| obj = Allocate(oddball_map(), OLD_DATA_SPACE); |
| if (obj->IsFailure()) return false; |
| set_undefined_value(obj); |
| ASSERT(!InNewSpace(undefined_value())); |
| |
| // Allocate initial symbol table. |
| obj = SymbolTable::Allocate(kInitialSymbolTableSize); |
| if (obj->IsFailure()) return false; |
| // Don't use set_symbol_table() due to asserts. |
| roots_[kSymbolTableRootIndex] = obj; |
| |
| // Assign the print strings for oddballs after creating symboltable. |
| Object* symbol = LookupAsciiSymbol("undefined"); |
| if (symbol->IsFailure()) return false; |
| Oddball::cast(undefined_value())->set_to_string(String::cast(symbol)); |
| Oddball::cast(undefined_value())->set_to_number(nan_value()); |
| |
| // Assign the print strings for oddballs after creating symboltable. |
| symbol = LookupAsciiSymbol("null"); |
| if (symbol->IsFailure()) return false; |
| Oddball::cast(null_value())->set_to_string(String::cast(symbol)); |
| Oddball::cast(null_value())->set_to_number(Smi::FromInt(0)); |
| |
| // Allocate the null_value |
| obj = Oddball::cast(null_value())->Initialize("null", Smi::FromInt(0)); |
| if (obj->IsFailure()) return false; |
| |
| obj = CreateOddball(oddball_map(), "true", Smi::FromInt(1)); |
| if (obj->IsFailure()) return false; |
| set_true_value(obj); |
| |
| obj = CreateOddball(oddball_map(), "false", Smi::FromInt(0)); |
| if (obj->IsFailure()) return false; |
| set_false_value(obj); |
| |
| obj = CreateOddball(oddball_map(), "hole", Smi::FromInt(-1)); |
| if (obj->IsFailure()) return false; |
| set_the_hole_value(obj); |
| |
| obj = CreateOddball( |
| oddball_map(), "no_interceptor_result_sentinel", Smi::FromInt(-2)); |
| if (obj->IsFailure()) return false; |
| set_no_interceptor_result_sentinel(obj); |
| |
| obj = CreateOddball(oddball_map(), "termination_exception", Smi::FromInt(-3)); |
| if (obj->IsFailure()) return false; |
| set_termination_exception(obj); |
| |
| // Allocate the empty string. |
| obj = AllocateRawAsciiString(0, TENURED); |
| if (obj->IsFailure()) return false; |
| set_empty_string(String::cast(obj)); |
| |
| for (unsigned i = 0; i < ARRAY_SIZE(constant_symbol_table); i++) { |
| obj = LookupAsciiSymbol(constant_symbol_table[i].contents); |
| if (obj->IsFailure()) 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. |
| obj = AllocateSymbol(CStrVector(""), 0, String::kHashComputedMask); |
| if (obj->IsFailure()) return false; |
| hidden_symbol_ = String::cast(obj); |
| |
| // Allocate the proxy for __proto__. |
| obj = AllocateProxy((Address) &Accessors::ObjectPrototype); |
| if (obj->IsFailure()) return false; |
| set_prototype_accessors(Proxy::cast(obj)); |
| |
| // Allocate the code_stubs dictionary. The initial size is set to avoid |
| // expanding the dictionary during bootstrapping. |
| obj = NumberDictionary::Allocate(128); |
| if (obj->IsFailure()) return false; |
| set_code_stubs(NumberDictionary::cast(obj)); |
| |
| // Allocate the non_monomorphic_cache used in stub-cache.cc. The initial size |
| // is set to avoid expanding the dictionary during bootstrapping. |
| obj = NumberDictionary::Allocate(64); |
| if (obj->IsFailure()) return false; |
| set_non_monomorphic_cache(NumberDictionary::cast(obj)); |
| |
| CreateFixedStubs(); |
| |
| // Allocate the number->string conversion cache |
| obj = AllocateFixedArray(kNumberStringCacheSize * 2); |
| if (obj->IsFailure()) return false; |
| set_number_string_cache(FixedArray::cast(obj)); |
| |
| // Allocate cache for single character strings. |
| obj = AllocateFixedArray(String::kMaxAsciiCharCode+1); |
| if (obj->IsFailure()) return false; |
| set_single_character_string_cache(FixedArray::cast(obj)); |
| |
| // Allocate cache for external strings pointing to native source code. |
| obj = AllocateFixedArray(Natives::GetBuiltinsCount()); |
| if (obj->IsFailure()) return false; |
| set_natives_source_cache(FixedArray::cast(obj)); |
| |
| // Handling of script id generation is in Factory::NewScript. |
| set_last_script_id(undefined_value()); |
| |
| // Initialize keyed lookup cache. |
| KeyedLookupCache::Clear(); |
| |
| // Initialize context slot cache. |
| ContextSlotCache::Clear(); |
| |
| // Initialize descriptor cache. |
| DescriptorLookupCache::Clear(); |
| |
| // Initialize compilation cache. |
| CompilationCache::Clear(); |
| |
| return true; |
| } |
| |
| |
| static inline int double_get_hash(double d) { |
| DoubleRepresentation rep(d); |
| return ((static_cast<int>(rep.bits) ^ static_cast<int>(rep.bits >> 32)) & |
| (Heap::kNumberStringCacheSize - 1)); |
| } |
| |
| |
| static inline int smi_get_hash(Smi* smi) { |
| return (smi->value() & (Heap::kNumberStringCacheSize - 1)); |
| } |
| |
| |
| |
| Object* Heap::GetNumberStringCache(Object* number) { |
| int hash; |
| if (number->IsSmi()) { |
| hash = smi_get_hash(Smi::cast(number)); |
| } else { |
| hash = double_get_hash(number->Number()); |
| } |
| 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; |
| if (number->IsSmi()) { |
| hash = smi_get_hash(Smi::cast(number)); |
| number_string_cache()->set(hash * 2, number, SKIP_WRITE_BARRIER); |
| } else { |
| hash = double_get_hash(number->Number()); |
| number_string_cache()->set(hash * 2, number); |
| } |
| number_string_cache()->set(hash * 2 + 1, string); |
| } |
| |
| |
| Object* Heap::SmiOrNumberFromDouble(double value, |
| bool new_object, |
| 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 plus_zero(0.0); |
| static const DoubleRepresentation minus_zero(-0.0); |
| static const DoubleRepresentation nan(OS::nan_value()); |
| ASSERT(minus_zero_value() != NULL); |
| ASSERT(sizeof(plus_zero.value) == sizeof(plus_zero.bits)); |
| |
| DoubleRepresentation rep(value); |
| if (rep.bits == plus_zero.bits) return Smi::FromInt(0); // not uncommon |
| if (rep.bits == minus_zero.bits) { |
| return new_object ? AllocateHeapNumber(-0.0, pretenure) |
| : minus_zero_value(); |
| } |
| if (rep.bits == nan.bits) { |
| return new_object |
| ? AllocateHeapNumber(OS::nan_value(), pretenure) |
| : nan_value(); |
| } |
| |
| // Try to represent the value as a tagged small integer. |
| int int_value = FastD2I(value); |
| if (value == FastI2D(int_value) && Smi::IsValid(int_value)) { |
| return Smi::FromInt(int_value); |
| } |
| |
| // Materialize the value in the heap. |
| return AllocateHeapNumber(value, pretenure); |
| } |
| |
| |
| Object* Heap::NewNumberFromDouble(double value, PretenureFlag pretenure) { |
| return SmiOrNumberFromDouble(value, |
| true /* number object must be new */, |
| pretenure); |
| } |
| |
| |
| Object* Heap::NumberFromDouble(double value, PretenureFlag pretenure) { |
| return SmiOrNumberFromDouble(value, |
| false /* use preallocated NaN, -0.0 */, |
| pretenure); |
| } |
| |
| |
| Object* Heap::AllocateProxy(Address proxy, PretenureFlag pretenure) { |
| // Statically ensure that it is safe to allocate proxies in paged spaces. |
| STATIC_ASSERT(Proxy::kSize <= Page::kMaxHeapObjectSize); |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| Object* result = Allocate(proxy_map(), space); |
| if (result->IsFailure()) return result; |
| |
| Proxy::cast(result)->set_proxy(proxy); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateSharedFunctionInfo(Object* name) { |
| Object* result = Allocate(shared_function_info_map(), OLD_POINTER_SPACE); |
| if (result->IsFailure()) return result; |
| |
| SharedFunctionInfo* share = SharedFunctionInfo::cast(result); |
| share->set_name(name); |
| Code* illegal = Builtins::builtin(Builtins::Illegal); |
| share->set_code(illegal); |
| Code* construct_stub = Builtins::builtin(Builtins::JSConstructStubGeneric); |
| share->set_construct_stub(construct_stub); |
| share->set_expected_nof_properties(0); |
| share->set_length(0); |
| share->set_formal_parameter_count(0); |
| share->set_instance_class_name(Object_symbol()); |
| share->set_function_data(undefined_value()); |
| share->set_script(undefined_value()); |
| share->set_start_position_and_type(0); |
| share->set_debug_info(undefined_value()); |
| share->set_inferred_name(empty_string()); |
| share->set_compiler_hints(0); |
| share->set_this_property_assignments_count(0); |
| share->set_this_property_assignments(undefined_value()); |
| return result; |
| } |
| |
| |
| Object* 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; |
| bool is_ascii = first->IsAsciiRepresentation() |
| && second->IsAsciiRepresentation(); |
| |
| // Make sure that an out of memory exception is thrown if the length |
| // of the new cons string is too large to fit in a Smi. |
| if (length > Smi::kMaxValue || length < -0) { |
| Top::context()->mark_out_of_memory(); |
| return Failure::OutOfMemoryException(); |
| } |
| |
| // If the resulting string is small make a flat string. |
| if (length < String::kMinNonFlatLength) { |
| ASSERT(first->IsFlat()); |
| ASSERT(second->IsFlat()); |
| if (is_ascii) { |
| Object* result = AllocateRawAsciiString(length); |
| if (result->IsFailure()) return result; |
| // Copy the characters into the new object. |
| char* dest = SeqAsciiString::cast(result)->GetChars(); |
| // Copy first part. |
| char* src = SeqAsciiString::cast(first)->GetChars(); |
| for (int i = 0; i < first_length; i++) *dest++ = src[i]; |
| // Copy second part. |
| src = SeqAsciiString::cast(second)->GetChars(); |
| for (int i = 0; i < second_length; i++) *dest++ = src[i]; |
| return result; |
| } else { |
| Object* result = AllocateRawTwoByteString(length); |
| if (result->IsFailure()) return 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; |
| if (length <= String::kMaxShortStringSize) { |
| map = is_ascii ? short_cons_ascii_string_map() |
| : short_cons_string_map(); |
| } else if (length <= String::kMaxMediumStringSize) { |
| map = is_ascii ? medium_cons_ascii_string_map() |
| : medium_cons_string_map(); |
| } else { |
| map = is_ascii ? long_cons_ascii_string_map() |
| : long_cons_string_map(); |
| } |
| |
| Object* result = Allocate(map, NEW_SPACE); |
| if (result->IsFailure()) return result; |
| ASSERT(InNewSpace(result)); |
| ConsString* cons_string = ConsString::cast(result); |
| cons_string->set_first(first, SKIP_WRITE_BARRIER); |
| cons_string->set_second(second, SKIP_WRITE_BARRIER); |
| cons_string->set_length(length); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateSlicedString(String* buffer, |
| int start, |
| int end) { |
| int length = end - start; |
| |
| // If the resulting string is small make a sub string. |
| if (length <= String::kMinNonFlatLength) { |
| return Heap::AllocateSubString(buffer, start, end); |
| } |
| |
| Map* map; |
| if (length <= String::kMaxShortStringSize) { |
| map = buffer->IsAsciiRepresentation() ? |
| short_sliced_ascii_string_map() : |
| short_sliced_string_map(); |
| } else if (length <= String::kMaxMediumStringSize) { |
| map = buffer->IsAsciiRepresentation() ? |
| medium_sliced_ascii_string_map() : |
| medium_sliced_string_map(); |
| } else { |
| map = buffer->IsAsciiRepresentation() ? |
| long_sliced_ascii_string_map() : |
| long_sliced_string_map(); |
| } |
| |
| Object* result = Allocate(map, NEW_SPACE); |
| if (result->IsFailure()) return result; |
| |
| SlicedString* sliced_string = SlicedString::cast(result); |
| sliced_string->set_buffer(buffer); |
| sliced_string->set_start(start); |
| sliced_string->set_length(length); |
| |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateSubString(String* buffer, |
| int start, |
| int end) { |
| int length = end - start; |
| |
| if (length == 1) { |
| return Heap::LookupSingleCharacterStringFromCode( |
| buffer->Get(start)); |
| } |
| |
| // Make an attempt to flatten the buffer to reduce access time. |
| if (!buffer->IsFlat()) { |
| buffer->TryFlatten(); |
| } |
| |
| Object* result = buffer->IsAsciiRepresentation() |
| ? AllocateRawAsciiString(length) |
| : AllocateRawTwoByteString(length); |
| if (result->IsFailure()) return result; |
| |
| // Copy the characters into the new object. |
| String* string_result = String::cast(result); |
| StringHasher hasher(length); |
| int i = 0; |
| for (; i < length && hasher.is_array_index(); i++) { |
| uc32 c = buffer->Get(start + i); |
| hasher.AddCharacter(c); |
| string_result->Set(i, c); |
| } |
| for (; i < length; i++) { |
| uc32 c = buffer->Get(start + i); |
| hasher.AddCharacterNoIndex(c); |
| string_result->Set(i, c); |
| } |
| string_result->set_length_field(hasher.GetHashField()); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateExternalStringFromAscii( |
| ExternalAsciiString::Resource* resource) { |
| Map* map; |
| int length = resource->length(); |
| if (length <= String::kMaxShortStringSize) { |
| map = short_external_ascii_string_map(); |
| } else if (length <= String::kMaxMediumStringSize) { |
| map = medium_external_ascii_string_map(); |
| } else { |
| map = long_external_ascii_string_map(); |
| } |
| |
| Object* result = Allocate(map, NEW_SPACE); |
| if (result->IsFailure()) return result; |
| |
| ExternalAsciiString* external_string = ExternalAsciiString::cast(result); |
| external_string->set_length(length); |
| external_string->set_resource(resource); |
| |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateExternalStringFromTwoByte( |
| ExternalTwoByteString::Resource* resource) { |
| int length = resource->length(); |
| |
| Map* map = ExternalTwoByteString::StringMap(length); |
| Object* result = Allocate(map, NEW_SPACE); |
| if (result->IsFailure()) return result; |
| |
| ExternalTwoByteString* external_string = ExternalTwoByteString::cast(result); |
| external_string->set_length(length); |
| external_string->set_resource(resource); |
| |
| return result; |
| } |
| |
| |
| Object* Heap::LookupSingleCharacterStringFromCode(uint16_t code) { |
| if (code <= String::kMaxAsciiCharCode) { |
| Object* value = Heap::single_character_string_cache()->get(code); |
| if (value != Heap::undefined_value()) return value; |
| |
| char buffer[1]; |
| buffer[0] = static_cast<char>(code); |
| Object* result = LookupSymbol(Vector<const char>(buffer, 1)); |
| |
| if (result->IsFailure()) return result; |
| Heap::single_character_string_cache()->set(code, result); |
| return result; |
| } |
| |
| Object* result = Heap::AllocateRawTwoByteString(1); |
| if (result->IsFailure()) return result; |
| String* answer = String::cast(result); |
| answer->Set(0, code); |
| return answer; |
| } |
| |
| |
| Object* Heap::AllocateByteArray(int length, PretenureFlag pretenure) { |
| if (pretenure == NOT_TENURED) { |
| return AllocateByteArray(length); |
| } |
| int size = ByteArray::SizeFor(length); |
| AllocationSpace space = |
| size > MaxObjectSizeInPagedSpace() ? LO_SPACE : OLD_DATA_SPACE; |
| |
| Object* result = AllocateRaw(size, space, OLD_DATA_SPACE); |
| |
| if (result->IsFailure()) return result; |
| |
| reinterpret_cast<Array*>(result)->set_map(byte_array_map()); |
| reinterpret_cast<Array*>(result)->set_length(length); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateByteArray(int length) { |
| int size = ByteArray::SizeFor(length); |
| AllocationSpace space = |
| size > MaxObjectSizeInPagedSpace() ? LO_SPACE : NEW_SPACE; |
| |
| Object* result = AllocateRaw(size, space, OLD_DATA_SPACE); |
| |
| if (result->IsFailure()) return result; |
| |
| reinterpret_cast<Array*>(result)->set_map(byte_array_map()); |
| reinterpret_cast<Array*>(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(Heap::one_pointer_filler_map()); |
| } else { |
| filler->set_map(Heap::byte_array_map()); |
| ByteArray::cast(filler)->set_length(ByteArray::LengthFor(size)); |
| } |
| } |
| |
| |
| Object* Heap::AllocatePixelArray(int length, |
| uint8_t* external_pointer, |
| PretenureFlag pretenure) { |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| |
| Object* result = AllocateRaw(PixelArray::kAlignedSize, space, OLD_DATA_SPACE); |
| |
| if (result->IsFailure()) return result; |
| |
| reinterpret_cast<PixelArray*>(result)->set_map(pixel_array_map()); |
| reinterpret_cast<PixelArray*>(result)->set_length(length); |
| reinterpret_cast<PixelArray*>(result)->set_external_pointer(external_pointer); |
| |
| return result; |
| } |
| |
| |
| Object* Heap::CreateCode(const CodeDesc& desc, |
| ZoneScopeInfo* sinfo, |
| Code::Flags flags, |
| Handle<Object> self_reference) { |
| // Compute size |
| int body_size = RoundUp(desc.instr_size + desc.reloc_size, kObjectAlignment); |
| int sinfo_size = 0; |
| if (sinfo != NULL) sinfo_size = sinfo->Serialize(NULL); |
| int obj_size = Code::SizeFor(body_size, sinfo_size); |
| ASSERT(IsAligned(obj_size, Code::kCodeAlignment)); |
| Object* result; |
| if (obj_size > MaxObjectSizeInPagedSpace()) { |
| result = lo_space_->AllocateRawCode(obj_size); |
| } else { |
| result = code_space_->AllocateRaw(obj_size); |
| } |
| |
| if (result->IsFailure()) return result; |
| |
| // Initialize the object |
| HeapObject::cast(result)->set_map(code_map()); |
| Code* code = Code::cast(result); |
| code->set_instruction_size(desc.instr_size); |
| code->set_relocation_size(desc.reloc_size); |
| code->set_sinfo_size(sinfo_size); |
| code->set_flags(flags); |
| // 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); |
| if (sinfo != NULL) sinfo->Serialize(code); // write scope info |
| |
| #ifdef DEBUG |
| code->Verify(); |
| #endif |
| return code; |
| } |
| |
| |
| Object* Heap::CopyCode(Code* code) { |
| // Allocate an object the same size as the code object. |
| int obj_size = code->Size(); |
| Object* result; |
| if (obj_size > MaxObjectSizeInPagedSpace()) { |
| result = lo_space_->AllocateRawCode(obj_size); |
| } else { |
| result = code_space_->AllocateRaw(obj_size); |
| } |
| |
| if (result->IsFailure()) return result; |
| |
| // Copy code object. |
| Address old_addr = code->address(); |
| Address new_addr = reinterpret_cast<HeapObject*>(result)->address(); |
| CopyBlock(reinterpret_cast<Object**>(new_addr), |
| reinterpret_cast<Object**>(old_addr), |
| obj_size); |
| // Relocate the copy. |
| Code* new_code = Code::cast(result); |
| new_code->Relocate(new_addr - old_addr); |
| return new_code; |
| } |
| |
| |
| Object* Heap::Allocate(Map* map, AllocationSpace space) { |
| ASSERT(gc_state_ == NOT_IN_GC); |
| ASSERT(map->instance_type() != MAP_TYPE); |
| Object* result = AllocateRaw(map->instance_size(), |
| space, |
| TargetSpaceId(map->instance_type())); |
| if (result->IsFailure()) return result; |
| HeapObject::cast(result)->set_map(map); |
| return result; |
| } |
| |
| |
| Object* Heap::InitializeFunction(JSFunction* function, |
| SharedFunctionInfo* shared, |
| Object* prototype) { |
| ASSERT(!prototype->IsMap()); |
| function->initialize_properties(); |
| function->initialize_elements(); |
| function->set_shared(shared); |
| function->set_prototype_or_initial_map(prototype); |
| function->set_context(undefined_value()); |
| function->set_literals(empty_fixed_array(), SKIP_WRITE_BARRIER); |
| return function; |
| } |
| |
| |
| Object* Heap::AllocateFunctionPrototype(JSFunction* function) { |
| // Allocate the prototype. Make sure to use the object function |
| // from the function's context, since the function can be from a |
| // different context. |
| JSFunction* object_function = |
| function->context()->global_context()->object_function(); |
| Object* prototype = AllocateJSObject(object_function); |
| if (prototype->IsFailure()) return prototype; |
| // When creating the prototype for the function we must set its |
| // constructor to the function. |
| Object* result = |
| JSObject::cast(prototype)->SetProperty(constructor_symbol(), |
| function, |
| DONT_ENUM); |
| if (result->IsFailure()) return result; |
| return prototype; |
| } |
| |
| |
| Object* Heap::AllocateFunction(Map* function_map, |
| SharedFunctionInfo* shared, |
| Object* prototype) { |
| Object* result = Allocate(function_map, OLD_POINTER_SPACE); |
| if (result->IsFailure()) return result; |
| return InitializeFunction(JSFunction::cast(result), shared, prototype); |
| } |
| |
| |
| Object* Heap::AllocateArgumentsObject(Object* callee, int length) { |
| // To get fast allocation and map sharing for arguments objects we |
| // allocate them based on an arguments boilerplate. |
| |
| // This calls Copy directly rather than using Heap::AllocateRaw so we |
| // duplicate the check here. |
| ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| |
| JSObject* boilerplate = |
| Top::context()->global_context()->arguments_boilerplate(); |
| |
| // Make the clone. |
| Map* map = boilerplate->map(); |
| int object_size = map->instance_size(); |
| Object* result = AllocateRaw(object_size, NEW_SPACE, OLD_POINTER_SPACE); |
| if (result->IsFailure()) return 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(reinterpret_cast<Object**>(HeapObject::cast(result)->address()), |
| reinterpret_cast<Object**>(boilerplate->address()), |
| object_size); |
| |
| // Set the two properties. |
| JSObject::cast(result)->InObjectPropertyAtPut(arguments_callee_index, |
| callee); |
| JSObject::cast(result)->InObjectPropertyAtPut(arguments_length_index, |
| Smi::FromInt(length), |
| SKIP_WRITE_BARRIER); |
| |
| // Check the state of the object |
| ASSERT(JSObject::cast(result)->HasFastProperties()); |
| ASSERT(JSObject::cast(result)->HasFastElements()); |
| |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateInitialMap(JSFunction* fun) { |
| ASSERT(!fun->has_initial_map()); |
| |
| // First create a new map with the size and number of in-object properties |
| // suggested by the function. |
| int instance_size = fun->shared()->CalculateInstanceSize(); |
| int in_object_properties = fun->shared()->CalculateInObjectProperties(); |
| Object* map_obj = Heap::AllocateMap(JS_OBJECT_TYPE, instance_size); |
| if (map_obj->IsFailure()) return map_obj; |
| |
| // Fetch or allocate prototype. |
| Object* prototype; |
| if (fun->has_instance_prototype()) { |
| prototype = fun->instance_prototype(); |
| } else { |
| prototype = AllocateFunctionPrototype(fun); |
| if (prototype->IsFailure()) return prototype; |
| } |
| Map* map = Map::cast(map_obj); |
| map->set_inobject_properties(in_object_properties); |
| map->set_unused_property_fields(in_object_properties); |
| map->set_prototype(prototype); |
| |
| // 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. |
| ASSERT(in_object_properties <= Map::kMaxPreAllocatedPropertyFields); |
| if (fun->shared()->has_only_this_property_assignments() && |
| fun->shared()->this_property_assignments_count() > 0) { |
| int count = fun->shared()->this_property_assignments_count(); |
| if (count > in_object_properties) { |
| count = in_object_properties; |
| } |
| Object* descriptors_obj = DescriptorArray::Allocate(count); |
| if (descriptors_obj->IsFailure()) return descriptors_obj; |
| DescriptorArray* descriptors = DescriptorArray::cast(descriptors_obj); |
| for (int i = 0; i < count; i++) { |
| String* name = fun->shared()->GetThisPropertyAssignmentName(i); |
| ASSERT(name->IsSymbol()); |
| FieldDescriptor field(name, i, NONE); |
| descriptors->Set(i, &field); |
| } |
| descriptors->Sort(); |
| map->set_instance_descriptors(descriptors); |
| map->set_pre_allocated_property_fields(count); |
| map->set_unused_property_fields(in_object_properties - count); |
| } |
| return map; |
| } |
| |
| |
| void Heap::InitializeJSObjectFromMap(JSObject* obj, |
| FixedArray* properties, |
| Map* map) { |
| obj->set_properties(properties); |
| obj->initialize_elements(); |
| // TODO(1240798): Initialize the object's body using valid initial values |
| // according to the object's initial map. For example, if the map's |
| // instance type is JS_ARRAY_TYPE, the length field should be initialized |
| // to a number (eg, Smi::FromInt(0)) and the elements initialized to a |
| // fixed array (eg, Heap::empty_fixed_array()). Currently, the object |
| // verification code has to cope with (temporarily) invalid objects. See |
| // for example, JSArray::JSArrayVerify). |
| obj->InitializeBody(map->instance_size()); |
| } |
| |
| |
| Object* 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 globla objects should be allocated using |
| // AllocateGloblaObject 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 = AllocateFixedArray(prop_size, pretenure); |
| if (properties->IsFailure()) return properties; |
| |
| // Allocate the JSObject. |
| AllocationSpace space = |
| (pretenure == TENURED) ? OLD_POINTER_SPACE : NEW_SPACE; |
| if (map->instance_size() > MaxObjectSizeInPagedSpace()) space = LO_SPACE; |
| Object* obj = Allocate(map, space); |
| if (obj->IsFailure()) return obj; |
| |
| // Initialize the JSObject. |
| InitializeJSObjectFromMap(JSObject::cast(obj), |
| FixedArray::cast(properties), |
| map); |
| return obj; |
| } |
| |
| |
| Object* Heap::AllocateJSObject(JSFunction* constructor, |
| PretenureFlag pretenure) { |
| // Allocate the initial map if absent. |
| if (!constructor->has_initial_map()) { |
| Object* initial_map = AllocateInitialMap(constructor); |
| if (initial_map->IsFailure()) return 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. |
| Object* result = |
| AllocateJSObjectFromMap(constructor->initial_map(), pretenure); |
| // Make sure result is NOT a global object if valid. |
| ASSERT(result->IsFailure() || !result->IsGlobalObject()); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateGlobalObject(JSFunction* constructor) { |
| ASSERT(constructor->has_initial_map()); |
| Map* map = constructor->initial_map(); |
| |
| // Make sure no field properties are described in the initial map. |
| // This guarantees us that normalizing the properties does not |
| // require us to change property values to JSGlobalPropertyCells. |
| ASSERT(map->NextFreePropertyIndex() == 0); |
| |
| // Make sure we don't have a ton of pre-allocated slots in the |
| // global objects. They will be unused once we normalize the object. |
| ASSERT(map->unused_property_fields() == 0); |
| ASSERT(map->inobject_properties() == 0); |
| |
| // Initial size of the backing store to avoid resize of the storage during |
| // bootstrapping. The size differs between the JS global object ad the |
| // builtins object. |
| int initial_size = map->instance_type() == JS_GLOBAL_OBJECT_TYPE ? 64 : 512; |
| |
| // Allocate a dictionary object for backing storage. |
| Object* obj = |
| StringDictionary::Allocate( |
| map->NumberOfDescribedProperties() * 2 + initial_size); |
| if (obj->IsFailure()) return obj; |
| StringDictionary* dictionary = StringDictionary::cast(obj); |
| |
| // The global object might be created from an object template with accessors. |
| // Fill these accessors into the dictionary. |
| DescriptorArray* descs = map->instance_descriptors(); |
| for (int i = 0; i < descs->number_of_descriptors(); i++) { |
| PropertyDetails details = descs->GetDetails(i); |
| ASSERT(details.type() == CALLBACKS); // Only accessors are expected. |
| PropertyDetails d = |
| PropertyDetails(details.attributes(), CALLBACKS, details.index()); |
| Object* value = descs->GetCallbacksObject(i); |
| value = Heap::AllocateJSGlobalPropertyCell(value); |
| if (value->IsFailure()) return value; |
| |
| Object* result = dictionary->Add(descs->GetKey(i), value, d); |
| if (result->IsFailure()) return result; |
| dictionary = StringDictionary::cast(result); |
| } |
| |
| // Allocate the global object and initialize it with the backing store. |
| obj = Allocate(map, OLD_POINTER_SPACE); |
| if (obj->IsFailure()) return obj; |
| JSObject* global = JSObject::cast(obj); |
| InitializeJSObjectFromMap(global, dictionary, map); |
| |
| // Create a new map for the global object. |
| obj = map->CopyDropDescriptors(); |
| if (obj->IsFailure()) return obj; |
| Map* new_map = Map::cast(obj); |
| |
| // Setup the global object as a normalized object. |
| global->set_map(new_map); |
| global->map()->set_instance_descriptors(Heap::empty_descriptor_array()); |
| global->set_properties(dictionary); |
| |
| // Make sure result is a global object with properties in dictionary. |
| ASSERT(global->IsGlobalObject()); |
| ASSERT(!global->HasFastProperties()); |
| return global; |
| } |
| |
| |
| Object* Heap::CopyJSObject(JSObject* source) { |
| // Never used to copy functions. If functions need to be copied we |
| // have to be careful to clear the literals array. |
| ASSERT(!source->IsJSFunction()); |
| |
| // Make the clone. |
| Map* map = source->map(); |
| int object_size = map->instance_size(); |
| Object* clone; |
| |
| // If we're forced to always allocate, we use the general allocation |
| // functions which may leave us with an object in old space. |
| if (always_allocate()) { |
| clone = AllocateRaw(object_size, NEW_SPACE, OLD_POINTER_SPACE); |
| if (clone->IsFailure()) return clone; |
| Address clone_address = HeapObject::cast(clone)->address(); |
| CopyBlock(reinterpret_cast<Object**>(clone_address), |
| reinterpret_cast<Object**>(source->address()), |
| object_size); |
| // Update write barrier for all fields that lie beyond the header. |
| for (int offset = JSObject::kHeaderSize; |
| offset < object_size; |
| offset += kPointerSize) { |
| RecordWrite(clone_address, offset); |
| } |
| } else { |
| clone = new_space_.AllocateRaw(object_size); |
| if (clone->IsFailure()) return clone; |
| ASSERT(Heap::InNewSpace(clone)); |
| // Since we know the clone is allocated in new space, we can copy |
| // the contents without worrying about updating the write barrier. |
| CopyBlock(reinterpret_cast<Object**>(HeapObject::cast(clone)->address()), |
| reinterpret_cast<Object**>(source->address()), |
| object_size); |
| } |
| |
| FixedArray* elements = FixedArray::cast(source->elements()); |
| FixedArray* properties = FixedArray::cast(source->properties()); |
| // Update elements if necessary. |
| if (elements->length()> 0) { |
| Object* elem = CopyFixedArray(elements); |
| if (elem->IsFailure()) return elem; |
| JSObject::cast(clone)->set_elements(FixedArray::cast(elem)); |
| } |
| // Update properties if necessary. |
| if (properties->length() > 0) { |
| Object* prop = CopyFixedArray(properties); |
| if (prop->IsFailure()) return prop; |
| JSObject::cast(clone)->set_properties(FixedArray::cast(prop)); |
| } |
| // Return the new clone. |
| return clone; |
| } |
| |
| |
| Object* Heap::ReinitializeJSGlobalProxy(JSFunction* constructor, |
| JSGlobalProxy* object) { |
| // Allocate initial map if absent. |
| if (!constructor->has_initial_map()) { |
| Object* initial_map = AllocateInitialMap(constructor); |
| if (initial_map->IsFailure()) return initial_map; |
| constructor->set_initial_map(Map::cast(initial_map)); |
| Map::cast(initial_map)->set_constructor(constructor); |
| } |
| |
| Map* map = constructor->initial_map(); |
| |
| // Check that the already allocated object has the same size as |
| // objects allocated using the constructor. |
| ASSERT(map->instance_size() == object->map()->instance_size()); |
| |
| // Allocate the backing storage for the properties. |
| int prop_size = map->unused_property_fields() - map->inobject_properties(); |
| Object* properties = AllocateFixedArray(prop_size, TENURED); |
| if (properties->IsFailure()) return 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; |
| } |
| |
| |
| Object* Heap::AllocateStringFromAscii(Vector<const char> string, |
| PretenureFlag pretenure) { |
| Object* result = AllocateRawAsciiString(string.length(), pretenure); |
| if (result->IsFailure()) return 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; |
| } |
| |
| |
| Object* Heap::AllocateStringFromUtf8(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<Scanner::Utf8Decoder> decoder(Scanner::utf8_decoder()); |
| decoder->Reset(string.start(), string.length()); |
| int chars = 0; |
| bool is_ascii = true; |
| while (decoder->has_more()) { |
| uc32 r = decoder->GetNext(); |
| if (r > String::kMaxAsciiCharCode) is_ascii = false; |
| chars++; |
| } |
| |
| // If the string is ascii, we do not need to convert the characters |
| // since UTF8 is backwards compatible with ascii. |
| if (is_ascii) return AllocateStringFromAscii(string, pretenure); |
| |
| Object* result = AllocateRawTwoByteString(chars, pretenure); |
| if (result->IsFailure()) return result; |
| |
| // Convert and copy the characters into the new object. |
| String* string_result = String::cast(result); |
| decoder->Reset(string.start(), string.length()); |
| for (int i = 0; i < chars; i++) { |
| uc32 r = decoder->GetNext(); |
| string_result->Set(i, r); |
| } |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateStringFromTwoByte(Vector<const uc16> string, |
| PretenureFlag pretenure) { |
| // Check if the string is an ASCII string. |
| int i = 0; |
| while (i < string.length() && string[i] <= String::kMaxAsciiCharCode) i++; |
| |
| Object* result; |
| if (i == string.length()) { // It's an ASCII string. |
| result = AllocateRawAsciiString(string.length(), pretenure); |
| } else { // It's not an ASCII string. |
| result = AllocateRawTwoByteString(string.length(), pretenure); |
| } |
| if (result->IsFailure()) return result; |
| |
| // Copy the characters into the new object, which may be either ASCII or |
| // UTF-16. |
| String* string_result = String::cast(result); |
| for (int i = 0; i < string.length(); i++) { |
| string_result->Set(i, string[i]); |
| } |
| return result; |
| } |
| |
| |
| Map* Heap::SymbolMapForString(String* string) { |
| // If the string is in new space it cannot be used as a symbol. |
| if (InNewSpace(string)) return NULL; |
| |
| // Find the corresponding symbol map for strings. |
| Map* map = string->map(); |
| |
| if (map == short_ascii_string_map()) return short_ascii_symbol_map(); |
| if (map == medium_ascii_string_map()) return medium_ascii_symbol_map(); |
| if (map == long_ascii_string_map()) return long_ascii_symbol_map(); |
| |
| if (map == short_string_map()) return short_symbol_map(); |
| if (map == medium_string_map()) return medium_symbol_map(); |
| if (map == long_string_map()) return long_symbol_map(); |
| |
| if (map == short_cons_string_map()) return short_cons_symbol_map(); |
| if (map == medium_cons_string_map()) return medium_cons_symbol_map(); |
| if (map == long_cons_string_map()) return long_cons_symbol_map(); |
| |
| if (map == short_cons_ascii_string_map()) { |
| return short_cons_ascii_symbol_map(); |
| } |
| if (map == medium_cons_ascii_string_map()) { |
| return medium_cons_ascii_symbol_map(); |
| } |
| if (map == long_cons_ascii_string_map()) { |
| return long_cons_ascii_symbol_map(); |
| } |
| |
| if (map == short_sliced_string_map()) return short_sliced_symbol_map(); |
| if (map == medium_sliced_string_map()) return medium_sliced_symbol_map(); |
| if (map == long_sliced_string_map()) return long_sliced_symbol_map(); |
| |
| if (map == short_sliced_ascii_string_map()) { |
| return short_sliced_ascii_symbol_map(); |
| } |
| if (map == medium_sliced_ascii_string_map()) { |
| return medium_sliced_ascii_symbol_map(); |
| } |
| if (map == long_sliced_ascii_string_map()) { |
| return long_sliced_ascii_symbol_map(); |
| } |
| |
| if (map == short_external_string_map()) { |
| return short_external_symbol_map(); |
| } |
| if (map == medium_external_string_map()) { |
| return medium_external_symbol_map(); |
| } |
| if (map == long_external_string_map()) { |
| return long_external_symbol_map(); |
| } |
| |
| if (map == short_external_ascii_string_map()) { |
| return short_external_ascii_symbol_map(); |
| } |
| if (map == medium_external_ascii_string_map()) { |
| return medium_external_ascii_symbol_map(); |
| } |
| if (map == long_external_ascii_string_map()) { |
| return long_external_ascii_symbol_map(); |
| } |
| |
| // No match found. |
| return NULL; |
| } |
| |
| |
| Object* Heap::AllocateInternalSymbol(unibrow::CharacterStream* buffer, |
| int chars, |
| uint32_t length_field) { |
| // Ensure the chars matches the number of characters in the buffer. |
| ASSERT(static_cast<unsigned>(chars) == buffer->Length()); |
| // Determine whether the string is ascii. |
| bool is_ascii = true; |
| while (buffer->has_more() && is_ascii) { |
| if (buffer->GetNext() > unibrow::Utf8::kMaxOneByteChar) is_ascii = false; |
| } |
| buffer->Rewind(); |
| |
| // Compute map and object size. |
| int size; |
| Map* map; |
| |
| if (is_ascii) { |
| if (chars <= String::kMaxShortStringSize) { |
| map = short_ascii_symbol_map(); |
| } else if (chars <= String::kMaxMediumStringSize) { |
| map = medium_ascii_symbol_map(); |
| } else { |
| map = long_ascii_symbol_map(); |
| } |
| size = SeqAsciiString::SizeFor(chars); |
| } else { |
| if (chars <= String::kMaxShortStringSize) { |
| map = short_symbol_map(); |
| } else if (chars <= String::kMaxMediumStringSize) { |
| map = medium_symbol_map(); |
| } else { |
| map = long_symbol_map(); |
| } |
| size = SeqTwoByteString::SizeFor(chars); |
| } |
| |
| // Allocate string. |
| AllocationSpace space = |
| (size > MaxObjectSizeInPagedSpace()) ? LO_SPACE : OLD_DATA_SPACE; |
| Object* result = AllocateRaw(size, space, OLD_DATA_SPACE); |
| if (result->IsFailure()) return result; |
| |
| reinterpret_cast<HeapObject*>(result)->set_map(map); |
| // The hash value contains the length of the string. |
| String* answer = String::cast(result); |
| answer->set_length_field(length_field); |
| |
| ASSERT_EQ(size, answer->Size()); |
| |
| // Fill in the characters. |
| for (int i = 0; i < chars; i++) { |
| answer->Set(i, buffer->GetNext()); |
| } |
| return answer; |
| } |
| |
| |
| Object* Heap::AllocateRawAsciiString(int length, PretenureFlag pretenure) { |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| int size = SeqAsciiString::SizeFor(length); |
| |
| Object* result = Failure::OutOfMemoryException(); |
| if (space == NEW_SPACE) { |
| result = size <= kMaxObjectSizeInNewSpace |
| ? new_space_.AllocateRaw(size) |
| : lo_space_->AllocateRawFixedArray(size); |
| } else { |
| if (size > MaxObjectSizeInPagedSpace()) space = LO_SPACE; |
| result = AllocateRaw(size, space, OLD_DATA_SPACE); |
| } |
| if (result->IsFailure()) return result; |
| |
| // Determine the map based on the string's length. |
| Map* map; |
| if (length <= String::kMaxShortStringSize) { |
| map = short_ascii_string_map(); |
| } else if (length <= String::kMaxMediumStringSize) { |
| map = medium_ascii_string_map(); |
| } else { |
| map = long_ascii_string_map(); |
| } |
| |
| // Partially initialize the object. |
| HeapObject::cast(result)->set_map(map); |
| String::cast(result)->set_length(length); |
| ASSERT_EQ(size, HeapObject::cast(result)->Size()); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateRawTwoByteString(int length, PretenureFlag pretenure) { |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| int size = SeqTwoByteString::SizeFor(length); |
| |
| Object* result = Failure::OutOfMemoryException(); |
| if (space == NEW_SPACE) { |
| result = size <= kMaxObjectSizeInNewSpace |
| ? new_space_.AllocateRaw(size) |
| : lo_space_->AllocateRawFixedArray(size); |
| } else { |
| if (size > MaxObjectSizeInPagedSpace()) space = LO_SPACE; |
| result = AllocateRaw(size, space, OLD_DATA_SPACE); |
| } |
| if (result->IsFailure()) return result; |
| |
| // Determine the map based on the string's length. |
| Map* map; |
| if (length <= String::kMaxShortStringSize) { |
| map = short_string_map(); |
| } else if (length <= String::kMaxMediumStringSize) { |
| map = medium_string_map(); |
| } else { |
| map = long_string_map(); |
| } |
| |
| // Partially initialize the object. |
| HeapObject::cast(result)->set_map(map); |
| String::cast(result)->set_length(length); |
| ASSERT_EQ(size, HeapObject::cast(result)->Size()); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateEmptyFixedArray() { |
| int size = FixedArray::SizeFor(0); |
| Object* result = AllocateRaw(size, OLD_DATA_SPACE, OLD_DATA_SPACE); |
| if (result->IsFailure()) return result; |
| // Initialize the object. |
| reinterpret_cast<Array*>(result)->set_map(fixed_array_map()); |
| reinterpret_cast<Array*>(result)->set_length(0); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateRawFixedArray(int length) { |
| // Use the general function if we're forced to always allocate. |
| if (always_allocate()) return AllocateFixedArray(length, NOT_TENURED); |
| // Allocate the raw data for a fixed array. |
| int size = FixedArray::SizeFor(length); |
| return size <= kMaxObjectSizeInNewSpace |
| ? new_space_.AllocateRaw(size) |
| : lo_space_->AllocateRawFixedArray(size); |
| } |
| |
| |
| Object* Heap::CopyFixedArray(FixedArray* src) { |
| int len = src->length(); |
| Object* obj = AllocateRawFixedArray(len); |
| if (obj->IsFailure()) return obj; |
| if (Heap::InNewSpace(obj)) { |
| HeapObject* dst = HeapObject::cast(obj); |
| CopyBlock(reinterpret_cast<Object**>(dst->address()), |
| reinterpret_cast<Object**>(src->address()), |
| FixedArray::SizeFor(len)); |
| return obj; |
| } |
| HeapObject::cast(obj)->set_map(src->map()); |
| FixedArray* result = FixedArray::cast(obj); |
| result->set_length(len); |
| // Copy the content |
| WriteBarrierMode mode = result->GetWriteBarrierMode(); |
| for (int i = 0; i < len; i++) result->set(i, src->get(i), mode); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateFixedArray(int length) { |
| ASSERT(length >= 0); |
| if (length == 0) return empty_fixed_array(); |
| Object* result = AllocateRawFixedArray(length); |
| if (!result->IsFailure()) { |
| // Initialize header. |
| reinterpret_cast<Array*>(result)->set_map(fixed_array_map()); |
| FixedArray* array = FixedArray::cast(result); |
| array->set_length(length); |
| Object* value = undefined_value(); |
| // Initialize body. |
| for (int index = 0; index < length; index++) { |
| array->set(index, value, SKIP_WRITE_BARRIER); |
| } |
| } |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateFixedArray(int length, PretenureFlag pretenure) { |
| ASSERT(empty_fixed_array()->IsFixedArray()); |
| if (length == 0) return empty_fixed_array(); |
| |
| int size = FixedArray::SizeFor(length); |
| Object* result = Failure::OutOfMemoryException(); |
| if (pretenure != TENURED) { |
| result = size <= kMaxObjectSizeInNewSpace |
| ? new_space_.AllocateRaw(size) |
| : lo_space_->AllocateRawFixedArray(size); |
| } |
| if (result->IsFailure()) { |
| if (size > MaxObjectSizeInPagedSpace()) { |
| result = lo_space_->AllocateRawFixedArray(size); |
| } else { |
| AllocationSpace space = |
| (pretenure == TENURED) ? OLD_POINTER_SPACE : NEW_SPACE; |
| result = AllocateRaw(size, space, OLD_POINTER_SPACE); |
| } |
| if (result->IsFailure()) return result; |
| } |
| // Initialize the object. |
| reinterpret_cast<Array*>(result)->set_map(fixed_array_map()); |
| FixedArray* array = FixedArray::cast(result); |
| array->set_length(length); |
| Object* value = undefined_value(); |
| for (int index = 0; index < length; index++) { |
| array->set(index, value, SKIP_WRITE_BARRIER); |
| } |
| return array; |
| } |
| |
| |
| Object* Heap::AllocateFixedArrayWithHoles(int length) { |
| if (length == 0) return empty_fixed_array(); |
| Object* result = AllocateRawFixedArray(length); |
| if (!result->IsFailure()) { |
| // Initialize header. |
| reinterpret_cast<Array*>(result)->set_map(fixed_array_map()); |
| FixedArray* array = FixedArray::cast(result); |
| array->set_length(length); |
| // Initialize body. |
| Object* value = the_hole_value(); |
| for (int index = 0; index < length; index++) { |
| array->set(index, value, SKIP_WRITE_BARRIER); |
| } |
| } |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateHashTable(int length) { |
| Object* result = Heap::AllocateFixedArray(length); |
| if (result->IsFailure()) return result; |
| reinterpret_cast<Array*>(result)->set_map(hash_table_map()); |
| ASSERT(result->IsHashTable()); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateGlobalContext() { |
| Object* result = Heap::AllocateFixedArray(Context::GLOBAL_CONTEXT_SLOTS); |
| if (result->IsFailure()) return result; |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map(global_context_map()); |
| ASSERT(context->IsGlobalContext()); |
| ASSERT(result->IsContext()); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateFunctionContext(int length, JSFunction* function) { |
| ASSERT(length >= Context::MIN_CONTEXT_SLOTS); |
| Object* result = Heap::AllocateFixedArray(length); |
| if (result->IsFailure()) return result; |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map(context_map()); |
| context->set_closure(function); |
| context->set_fcontext(context); |
| context->set_previous(NULL); |
| context->set_extension(NULL); |
| context->set_global(function->context()->global()); |
| ASSERT(!context->IsGlobalContext()); |
| ASSERT(context->is_function_context()); |
| ASSERT(result->IsContext()); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateWithContext(Context* previous, |
| JSObject* extension, |
| bool is_catch_context) { |
| Object* result = Heap::AllocateFixedArray(Context::MIN_CONTEXT_SLOTS); |
| if (result->IsFailure()) return result; |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_map(is_catch_context ? catch_context_map() : context_map()); |
| context->set_closure(previous->closure()); |
| context->set_fcontext(previous->fcontext()); |
| context->set_previous(previous); |
| context->set_extension(extension); |
| context->set_global(previous->global()); |
| ASSERT(!context->IsGlobalContext()); |
| ASSERT(!context->is_function_context()); |
| ASSERT(result->IsContext()); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateStruct(InstanceType type) { |
| Map* map; |
| switch (type) { |
| #define MAKE_CASE(NAME, Name, name) case NAME##_TYPE: map = name##_map(); break; |
| STRUCT_LIST(MAKE_CASE) |
| #undef MAKE_CASE |
| default: |
| UNREACHABLE(); |
| return Failure::InternalError(); |
| } |
| int size = map->instance_size(); |
| AllocationSpace space = |
| (size > MaxObjectSizeInPagedSpace()) ? LO_SPACE : OLD_POINTER_SPACE; |
| Object* result = Heap::Allocate(map, space); |
| if (result->IsFailure()) return result; |
| Struct::cast(result)->InitializeBody(size); |
| return result; |
| } |
| |
| |
| bool Heap::IdleNotification() { |
| static const int kIdlesBeforeScavenge = 4; |
| static const int kIdlesBeforeMarkSweep = 7; |
| static const int kIdlesBeforeMarkCompact = 8; |
| static int number_idle_notifications = 0; |
| static int last_gc_count = gc_count_; |
| |
| bool finished = false; |
| |
| if (last_gc_count == gc_count_) { |
| number_idle_notifications++; |
| } else { |
| number_idle_notifications = 0; |
| last_gc_count = gc_count_; |
| } |
| |
| if (number_idle_notifications == kIdlesBeforeScavenge) { |
| CollectGarbage(0, NEW_SPACE); |
| new_space_.Shrink(); |
| last_gc_count = gc_count_; |
| |
| } else if (number_idle_notifications == kIdlesBeforeMarkSweep) { |
| CollectAllGarbage(false); |
| new_space_.Shrink(); |
| last_gc_count = gc_count_; |
| |
| } else if (number_idle_notifications == kIdlesBeforeMarkCompact) { |
| CollectAllGarbage(true); |
| new_space_.Shrink(); |
| last_gc_count = gc_count_; |
| number_idle_notifications = 0; |
| finished = true; |
| } |
| |
| // Uncommit unused memory in new space. |
| Heap::UncommitFromSpace(); |
| return finished; |
| } |
| |
| |
| #ifdef DEBUG |
| |
| void Heap::Print() { |
| if (!HasBeenSetup()) return; |
| Top::PrintStack(); |
| AllSpaces spaces; |
| while (Space* space = spaces.next()) space->Print(); |
| } |
| |
| |
| void Heap::ReportCodeStatistics(const char* title) { |
| PrintF(">>>>>> Code Stats (%s) >>>>>>\n", title); |
| PagedSpace::ResetCodeStatistics(); |
| // We do not look for code in new space, map space, or old space. If code |
| // somehow ends up in those spaces, we would miss it here. |
| code_space_->CollectCodeStatistics(); |
| lo_space_->CollectCodeStatistics(); |
| PagedSpace::ReportCodeStatistics(); |
| } |
| |
| |
| // This function expects that NewSpace's allocated objects histogram is |
| // populated (via a call to CollectStatistics or else as a side effect of a |
| // just-completed scavenge collection). |
| void Heap::ReportHeapStatistics(const char* title) { |
| USE(title); |
| PrintF(">>>>>> =============== %s (%d) =============== >>>>>>\n", |
| title, gc_count_); |
| PrintF("mark-compact GC : %d\n", mc_count_); |
| PrintF("old_gen_promotion_limit_ %d\n", old_gen_promotion_limit_); |
| PrintF("old_gen_allocation_limit_ %d\n", old_gen_allocation_limit_); |
| |
| PrintF("\n"); |
| PrintF("Number of handles : %d\n", HandleScope::NumberOfHandles()); |
| GlobalHandles::PrintStats(); |
| PrintF("\n"); |
| |
| PrintF("Heap statistics : "); |
| MemoryAllocator::ReportStatistics(); |
| PrintF("To space : "); |
| new_space_.ReportStatistics(); |
| PrintF("Old pointer space : "); |
| old_pointer_space_->ReportStatistics(); |
| PrintF("Old data space : "); |
| old_data_space_->ReportStatistics(); |
| PrintF("Code space : "); |
| code_space_->ReportStatistics(); |
| PrintF("Map space : "); |
| map_space_->ReportStatistics(); |
| PrintF("Cell space : "); |
| cell_space_->ReportStatistics(); |
| PrintF("Large object space : "); |
| lo_space_->ReportStatistics(); |
| PrintF(">>>>>> ========================================= >>>>>>\n"); |
| } |
| |
| #endif // DEBUG |
| |
| bool Heap::Contains(HeapObject* value) { |
| return Contains(value->address()); |
| } |
| |
| |
| bool Heap::Contains(Address addr) { |
| if (OS::IsOutsideAllocatedSpace(addr)) return false; |
| return HasBeenSetup() && |
| (new_space_.ToSpaceContains(addr) || |
| old_pointer_space_->Contains(addr) || |
| old_data_space_->Contains(addr) || |
| code_space_->Contains(addr) || |
| map_space_->Contains(addr) || |
| cell_space_->Contains(addr) || |
| lo_space_->SlowContains(addr)); |
| } |
| |
| |
| bool Heap::InSpace(HeapObject* value, AllocationSpace space) { |
| return InSpace(value->address(), space); |
| } |
| |
| |
| bool Heap::InSpace(Address addr, AllocationSpace space) { |
| if (OS::IsOutsideAllocatedSpace(addr)) return false; |
| if (!HasBeenSetup()) return false; |
| |
| switch (space) { |
| case NEW_SPACE: |
| return new_space_.ToSpaceContains(addr); |
| case OLD_POINTER_SPACE: |
| return old_pointer_space_->Contains(addr); |
| case OLD_DATA_SPACE: |
| return old_data_space_->Contains(addr); |
| case CODE_SPACE: |
| return code_space_->Contains(addr); |
| case MAP_SPACE: |
| return map_space_->Contains(addr); |
| case CELL_SPACE: |
| return cell_space_->Contains(addr); |
| case LO_SPACE: |
| return lo_space_->SlowContains(addr); |
| } |
| |
| return false; |
| } |
| |
| |
| #ifdef DEBUG |
| void Heap::Verify() { |
| ASSERT(HasBeenSetup()); |
| |
| VerifyPointersVisitor visitor; |
| IterateRoots(&visitor); |
| |
| new_space_.Verify(); |
| |
| VerifyPointersAndRSetVisitor rset_visitor; |
| old_pointer_space_->Verify(&rset_visitor); |
| map_space_->Verify(&rset_visitor); |
| |
| VerifyPointersVisitor no_rset_visitor; |
| old_data_space_->Verify(&no_rset_visitor); |
| code_space_->Verify(&no_rset_visitor); |
| cell_space_->Verify(&no_rset_visitor); |
| |
| lo_space_->Verify(); |
| } |
| #endif // DEBUG |
| |
| |
| Object* Heap::LookupSymbol(Vector<const char> string) { |
| Object* symbol = NULL; |
| Object* new_table = symbol_table()->LookupSymbol(string, &symbol); |
| if (new_table->IsFailure()) return 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; |
| } |
| |
| |
| Object* Heap::LookupSymbol(String* string) { |
| if (string->IsSymbol()) return string; |
| Object* symbol = NULL; |
| Object* new_table = symbol_table()->LookupString(string, &symbol); |
| if (new_table->IsFailure()) return new_table; |
| // Can't use set_symbol_table because SymbolTable::cast knows that |
| // SymbolTable is a singleton and checks for identity. |
| roots_[kSymbolTableRootIndex] = new_table; |
| ASSERT(symbol != NULL); |
| return symbol; |
| } |
| |
| |
| bool Heap::LookupSymbolIfExists(String* string, String** symbol) { |
| if (string->IsSymbol()) { |
| *symbol = string; |
| return true; |
| } |
| return symbol_table()->LookupSymbolIfExists(string, symbol); |
| } |
| |
| |
| #ifdef DEBUG |
| void Heap::ZapFromSpace() { |
| ASSERT(reinterpret_cast<Object*>(kFromSpaceZapValue)->IsHeapObject()); |
| for (Address a = new_space_.FromSpaceLow(); |
| a < new_space_.FromSpaceHigh(); |
| a += kPointerSize) { |
| Memory::Address_at(a) = kFromSpaceZapValue; |
| } |
| } |
| #endif // DEBUG |
| |
| |
| int Heap::IterateRSetRange(Address object_start, |
| Address object_end, |
| Address rset_start, |
| ObjectSlotCallback copy_object_func) { |
| Address object_address = object_start; |
| Address rset_address = rset_start; |
| int set_bits_count = 0; |
| |
| // Loop over all the pointers in [object_start, object_end). |
| while (object_address < object_end) { |
| uint32_t rset_word = Memory::uint32_at(rset_address); |
| if (rset_word != 0) { |
| uint32_t result_rset = rset_word; |
| for (uint32_t bitmask = 1; bitmask != 0; bitmask = bitmask << 1) { |
| // Do not dereference pointers at or past object_end. |
| if ((rset_word & bitmask) != 0 && object_address < object_end) { |
| Object** object_p = reinterpret_cast<Object**>(object_address); |
| if (Heap::InNewSpace(*object_p)) { |
| copy_object_func(reinterpret_cast<HeapObject**>(object_p)); |
| } |
| // If this pointer does not need to be remembered anymore, clear |
| // the remembered set bit. |
| if (!Heap::InNewSpace(*object_p)) result_rset &= ~bitmask; |
| set_bits_count++; |
| } |
| object_address += kPointerSize; |
| } |
| // Update the remembered set if it has changed. |
| if (result_rset != rset_word) { |
| Memory::uint32_at(rset_address) = result_rset; |
| } |
| } else { |
| // No bits in the word were set. This is the common case. |
| object_address += kPointerSize * kBitsPerInt; |
| } |
| rset_address += kIntSize; |
| } |
| return set_bits_count; |
| } |
| |
| |
| void Heap::IterateRSet(PagedSpace* space, ObjectSlotCallback copy_object_func) { |
| ASSERT(Page::is_rset_in_use()); |
| ASSERT(space == old_pointer_space_ || space == map_space_); |
| |
| static void* paged_rset_histogram = StatsTable::CreateHistogram( |
| "V8.RSetPaged", |
| 0, |
| Page::kObjectAreaSize / kPointerSize, |
| 30); |
| |
| PageIterator it(space, PageIterator::PAGES_IN_USE); |
| while (it.has_next()) { |
| Page* page = it.next(); |
| int count = IterateRSetRange(page->ObjectAreaStart(), page->AllocationTop(), |
| page->RSetStart(), copy_object_func); |
| if (paged_rset_histogram != NULL) { |
| StatsTable::AddHistogramSample(paged_rset_histogram, count); |
| } |
| } |
| } |
| |
| |
| #ifdef DEBUG |
| #define SYNCHRONIZE_TAG(tag) v->Synchronize(tag) |
| #else |
| #define SYNCHRONIZE_TAG(tag) |
| #endif |
| |
| void Heap::IterateRoots(ObjectVisitor* v) { |
| IterateStrongRoots(v); |
| v->VisitPointer(reinterpret_cast<Object**>(&roots_[kSymbolTableRootIndex])); |
| SYNCHRONIZE_TAG("symbol_table"); |
| } |
| |
| |
| void Heap::IterateStrongRoots(ObjectVisitor* v) { |
| v->VisitPointers(&roots_[0], &roots_[kStrongRootListLength]); |
| SYNCHRONIZE_TAG("strong_root_list"); |
| |
| v->VisitPointer(bit_cast<Object**, String**>(&hidden_symbol_)); |
| SYNCHRONIZE_TAG("symbol"); |
| |
| Bootstrapper::Iterate(v); |
| SYNCHRONIZE_TAG("bootstrapper"); |
| Top::Iterate(v); |
| SYNCHRONIZE_TAG("top"); |
| |
| #ifdef ENABLE_DEBUGGER_SUPPORT |
| Debug::Iterate(v); |
| #endif |
| SYNCHRONIZE_TAG("debug"); |
| CompilationCache::Iterate(v); |
| SYNCHRONIZE_TAG("compilationcache"); |
| |
| // Iterate over local handles in handle scopes. |
| HandleScopeImplementer::Iterate(v); |
| SYNCHRONIZE_TAG("handlescope"); |
| |
| // Iterate over the builtin code objects and code stubs in the heap. Note |
| // that it is not strictly necessary to iterate over code objects on |
| // scavenge collections. We still do it here because this same function |
| // is used by the mark-sweep collector and the deserializer. |
| Builtins::IterateBuiltins(v); |
| SYNCHRONIZE_TAG("builtins"); |
| |
| // Iterate over global handles. |
| GlobalHandles::IterateRoots(v); |
| SYNCHRONIZE_TAG("globalhandles"); |
| |
| // Iterate over pointers being held by inactive threads. |
| ThreadManager::Iterate(v); |
| SYNCHRONIZE_TAG("threadmanager"); |
| } |
| #undef SYNCHRONIZE_TAG |
| |
| |
| // Flag is set when the heap has been configured. The heap can be repeatedly |
| // configured through the API until it is setup. |
| static bool heap_configured = false; |
| |
| // TODO(1236194): Since the heap size is configurable on the command line |
| // and through the API, we should gracefully handle the case that the heap |
| // size is not big enough to fit all the initial objects. |
| bool Heap::ConfigureHeap(int semispace_size, int old_gen_size) { |
| if (HasBeenSetup()) return false; |
| |
| if (semispace_size > 0) semispace_size_ = semispace_size; |
| if (old_gen_size > 0) old_generation_size_ = old_gen_size; |
| |
| // The new space size must be a power of two to support single-bit testing |
| // for containment. |
| semispace_size_ = RoundUpToPowerOf2(semispace_size_); |
| initial_semispace_size_ = Min(initial_semispace_size_, semispace_size_); |
| young_generation_size_ = 2 * semispace_size_; |
| external_allocation_limit_ = 10 * semispace_size_; |
| |
| // The old generation is paged. |
| old_generation_size_ = RoundUp(old_generation_size_, Page::kPageSize); |
| |
| heap_configured = true; |
| return true; |
| } |
| |
| |
| bool Heap::ConfigureHeapDefault() { |
| return ConfigureHeap(FLAG_new_space_size, FLAG_old_space_size); |
| } |
| |
| |
| int Heap::PromotedSpaceSize() { |
| return old_pointer_space_->Size() |
| + old_data_space_->Size() |
| + code_space_->Size() |
| + map_space_->Size() |
| + cell_space_->Size() |
| + lo_space_->Size(); |
| } |
| |
| |
| int Heap::PromotedExternalMemorySize() { |
| if (amount_of_external_allocated_memory_ |
| <= amount_of_external_allocated_memory_at_last_global_gc_) return 0; |
| return amount_of_external_allocated_memory_ |
| - amount_of_external_allocated_memory_at_last_global_gc_; |
| } |
| |
| |
| bool Heap::Setup(bool create_heap_objects) { |
| // Initialize heap spaces and initial maps and objects. Whenever something |
| // goes wrong, just return false. The caller should check the results and |
| // call Heap::TearDown() to release allocated memory. |
| // |
| // If the heap is not yet configured (eg, through the API), configure it. |
| // Configuration is based on the flags new-space-size (really the semispace |
| // size) and old-space-size if set or the initial values of semispace_size_ |
| // and old_generation_size_ otherwise. |
| if (!heap_configured) { |
| if (!ConfigureHeapDefault()) return false; |
| } |
| |
| // Setup memory allocator and reserve a chunk of memory for new |
| // space. The chunk is double the size of the new space to ensure |
| // that we can find a pair of semispaces that are contiguous and |
| // aligned to their size. |
| if (!MemoryAllocator::Setup(MaxCapacity())) return false; |
| void* chunk = |
| MemoryAllocator::ReserveInitialChunk(2 * young_generation_size_); |
| if (chunk == NULL) return false; |
| |
| // Align the pair of semispaces to their size, which must be a power |
| // of 2. |
| ASSERT(IsPowerOf2(young_generation_size_)); |
| Address new_space_start = |
| RoundUp(reinterpret_cast<byte*>(chunk), young_generation_size_); |
| if (!new_space_.Setup(new_space_start, young_generation_size_)) return false; |
| |
| // Initialize old pointer space. |
| old_pointer_space_ = |
| new OldSpace(old_generation_size_, OLD_POINTER_SPACE, NOT_EXECUTABLE); |
| if (old_pointer_space_ == NULL) return false; |
| if (!old_pointer_space_->Setup(NULL, 0)) return false; |
| |
| // Initialize old data space. |
| old_data_space_ = |
| new OldSpace(old_generation_size_, OLD_DATA_SPACE, NOT_EXECUTABLE); |
| if (old_data_space_ == NULL) return false; |
| if (!old_data_space_->Setup(NULL, 0)) return false; |
| |
| // Initialize the code space, set its maximum capacity to the old |
| // generation size. It needs executable memory. |
| code_space_ = |
| new OldSpace(old_generation_size_, CODE_SPACE, EXECUTABLE); |
| if (code_space_ == NULL) return false; |
| if (!code_space_->Setup(NULL, 0)) return false; |
| |
| // Initialize map space. |
| map_space_ = new MapSpace(kMaxMapSpaceSize, MAP_SPACE); |
| if (map_space_ == NULL) return false; |
| if (!map_space_->Setup(NULL, 0)) return false; |
| |
| // Initialize global property cell space. |
| cell_space_ = new CellSpace(old_generation_size_, CELL_SPACE); |
| if (cell_space_ == NULL) return false; |
| if (!cell_space_->Setup(NULL, 0)) return false; |
| |
| // The large object code space may contain code or data. We set the memory |
| // to be non-executable here for safety, but this means we need to enable it |
| // explicitly when allocating large code objects. |
| lo_space_ = new LargeObjectSpace(LO_SPACE); |
| if (lo_space_ == NULL) return false; |
| if (!lo_space_->Setup()) return false; |
| |
| if (create_heap_objects) { |
| // Create initial maps. |
| if (!CreateInitialMaps()) return false; |
| if (!CreateApiObjects()) return false; |
| |
| // Create initial objects |
| if (!CreateInitialObjects()) return false; |
| } |
| |
| LOG(IntEvent("heap-capacity", Capacity())); |
| LOG(IntEvent("heap-available", Available())); |
| |
| return true; |
| } |
| |
| |
| void Heap::SetStackLimit(intptr_t limit) { |
| // 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 entry containing the stack guard. |
| // This is actually an address, but the tag makes the GC ignore it. |
| roots_[kStackLimitRootIndex] = |
| reinterpret_cast<Object*>((limit & ~kSmiTagMask) | kSmiTag); |
| } |
| |
| |
| void Heap::TearDown() { |
| GlobalHandles::TearDown(); |
| |
| new_space_.TearDown(); |
| |
| if (old_pointer_space_ != NULL) { |
| old_pointer_space_->TearDown(); |
| delete old_pointer_space_; |
| old_pointer_space_ = NULL; |
| } |
| |
| if (old_data_space_ != NULL) { |
| old_data_space_->TearDown(); |
| delete old_data_space_; |
| old_data_space_ = NULL; |
| } |
| |
| if (code_space_ != NULL) { |
| code_space_->TearDown(); |
| delete code_space_; |
| code_space_ = NULL; |
| } |
| |
| if (map_space_ != NULL) { |
| map_space_->TearDown(); |
| delete map_space_; |
| map_space_ = NULL; |
| } |
| |
| if (cell_space_ != NULL) { |
| cell_space_->TearDown(); |
| delete cell_space_; |
| cell_space_ = NULL; |
| } |
| |
| if (lo_space_ != NULL) { |
| lo_space_->TearDown(); |
| delete lo_space_; |
| lo_space_ = NULL; |
| } |
| |
| MemoryAllocator::TearDown(); |
| } |
| |
| |
| void Heap::Shrink() { |
| // Try to shrink all paged spaces. |
| PagedSpaces spaces; |
| while (PagedSpace* space = spaces.next()) space->Shrink(); |
| } |
| |
| |
| #ifdef ENABLE_HEAP_PROTECTION |
| |
| void Heap::Protect() { |
| if (HasBeenSetup()) { |
| AllSpaces spaces; |
| while (Space* space = spaces.next()) space->Protect(); |
| } |
| } |
| |
| |
| void Heap::Unprotect() { |
| if (HasBeenSetup()) { |
| AllSpaces spaces; |
| while (Space* space = spaces.next()) space->Unprotect(); |
| } |
| } |
| |
| #endif |
| |
| |
| #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", p, *p); |
| } |
| }; |
| |
| void Heap::PrintHandles() { |
| PrintF("Handles:\n"); |
| PrintHandleVisitor v; |
| HandleScopeImplementer::Iterate(&v); |
| } |
| |
| #endif |
| |
| |
| Space* AllSpaces::next() { |
| switch (counter_++) { |
| case NEW_SPACE: |
| return Heap::new_space(); |
| case OLD_POINTER_SPACE: |
| return Heap::old_pointer_space(); |
| case OLD_DATA_SPACE: |
| return Heap::old_data_space(); |
| case CODE_SPACE: |
| return Heap::code_space(); |
| case MAP_SPACE: |
| return Heap::map_space(); |
| case CELL_SPACE: |
| return Heap::cell_space(); |
| case LO_SPACE: |
| return Heap::lo_space(); |
| default: |
| return NULL; |
| } |
| } |
| |
| |
| PagedSpace* PagedSpaces::next() { |
| switch (counter_++) { |
| case OLD_POINTER_SPACE: |
| return Heap::old_pointer_space(); |
| case OLD_DATA_SPACE: |
| return Heap::old_data_space(); |
| case CODE_SPACE: |
| return Heap::code_space(); |
| case MAP_SPACE: |
| return Heap::map_space(); |
| case CELL_SPACE: |
| return Heap::cell_space(); |
| default: |
| return NULL; |
| } |
| } |
| |
| |
| |
| OldSpace* OldSpaces::next() { |
| switch (counter_++) { |
| case OLD_POINTER_SPACE: |
| return Heap::old_pointer_space(); |
| case OLD_DATA_SPACE: |
| return Heap::old_data_space(); |
| case CODE_SPACE: |
| return Heap::code_space(); |
| default: |
| return NULL; |
| } |
| } |
| |
| |
| SpaceIterator::SpaceIterator() : current_space_(FIRST_SPACE), iterator_(NULL) { |
| } |
| |
| |
| 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()); |
| break; |
| case OLD_POINTER_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::old_pointer_space()); |
| break; |
| case OLD_DATA_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::old_data_space()); |
| break; |
| case CODE_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::code_space()); |
| break; |
| case MAP_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::map_space()); |
| break; |
| case CELL_SPACE: |
| iterator_ = new HeapObjectIterator(Heap::cell_space()); |
| break; |
| case LO_SPACE: |
| iterator_ = new LargeObjectIterator(Heap::lo_space()); |
| break; |
| } |
| |
| // Return the newly allocated iterator; |
| ASSERT(iterator_ != NULL); |
| return iterator_; |
| } |
| |
| |
| HeapIterator::HeapIterator() { |
| Init(); |
| } |
| |
| |
| HeapIterator::~HeapIterator() { |
| Shutdown(); |
| } |
| |
| |
| void HeapIterator::Init() { |
| // Start the iteration. |
| space_iterator_ = new SpaceIterator(); |
| object_iterator_ = space_iterator_->next(); |
| } |
| |
| |
| void HeapIterator::Shutdown() { |
| // Make sure the last iterator is deallocated. |
| delete space_iterator_; |
| space_iterator_ = NULL; |
| object_iterator_ = NULL; |
| } |
| |
| |
| bool HeapIterator::has_next() { |
| // No iterator means we are done. |
| if (object_iterator_ == NULL) return false; |
| |
| if (object_iterator_->has_next_object()) { |
| // If the current iterator has more objects we are fine. |
| return true; |
| } else { |
| // Go though the spaces looking for one that has objects. |
| while (space_iterator_->has_next()) { |
| object_iterator_ = space_iterator_->next(); |
| if (object_iterator_->has_next_object()) { |
| return true; |
| } |
| } |
| } |
| // Done with the last space. |
| object_iterator_ = NULL; |
| return false; |
| } |
| |
| |
| HeapObject* HeapIterator::next() { |
| if (has_next()) { |
| return object_iterator_->next_object(); |
| } else { |
| return NULL; |
| } |
| } |
| |
| |
| void HeapIterator::reset() { |
| // Restart the iterator. |
| Shutdown(); |
| Init(); |
| } |
| |
| |
| #ifdef DEBUG |
| |
| static bool search_for_any_global; |
| static Object* search_target; |
| static bool found_target; |
| static List<Object*> object_stack(20); |
| |
| |
| // Tags 0, 1, and 3 are used. Use 2 for marking visited HeapObject. |
| static const int kMarkTag = 2; |
| |
| static void MarkObjectRecursively(Object** p); |
| class MarkObjectVisitor : public ObjectVisitor { |
| public: |
| void VisitPointers(Object** start, Object** end) { |
| // Copy all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) |
| MarkObjectRecursively(p); |
| } |
| } |
| }; |
| |
| static MarkObjectVisitor mark_visitor; |
| |
| static 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(reinterpret_cast<Map*>(map_addr + kMarkTag)); |
| |
| MarkObjectRecursively(&map); |
| |
| 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(); |
| } |
| |
| |
| static void UnmarkObjectRecursively(Object** p); |
| class UnmarkObjectVisitor : public ObjectVisitor { |
| public: |
| void VisitPointers(Object** start, Object** end) { |
| // Copy all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) |
| UnmarkObjectRecursively(p); |
| } |
| } |
| }; |
| |
| static UnmarkObjectVisitor unmark_visitor; |
| |
| static 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(reinterpret_cast<Map*>(map_p)); |
| |
| UnmarkObjectRecursively(reinterpret_cast<Object**>(&map_p)); |
| |
| obj->IterateBody(Map::cast(map_p)->instance_type(), |
| obj->SizeFromMap(Map::cast(map_p)), |
| &unmark_visitor); |
| } |
| |
| |
| static 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: |
| void VisitPointers(Object** start, Object** end) { |
| // Visit all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) { |
| if ((*p)->IsHeapObject()) |
| MarkRootObjectRecursively(p); |
| } |
| } |
| }; |
| |
| |
| // 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() { |
| search_target = NULL; |
| search_for_any_global = false; |
| |
| MarkRootVisitor root_visitor; |
| IterateRoots(&root_visitor); |
| } |
| |
| |
| // 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() { |
| search_target = NULL; |
| search_for_any_global = true; |
| |
| MarkRootVisitor root_visitor; |
| IterateRoots(&root_visitor); |
| } |
| #endif |
| |
| |
| GCTracer::GCTracer() |
| : start_time_(0.0), |
| start_size_(0.0), |
| gc_count_(0), |
| full_gc_count_(0), |
| is_compacting_(false), |
| marked_count_(0) { |
| // These two fields reflect the state of the previous full collection. |
| // Set them before they are changed by the collector. |
| previous_has_compacted_ = MarkCompactCollector::HasCompacted(); |
| previous_marked_count_ = MarkCompactCollector::previous_marked_count(); |
| if (!FLAG_trace_gc) return; |
| start_time_ = OS::TimeCurrentMillis(); |
| start_size_ = SizeOfHeapObjects(); |
| } |
| |
| |
| GCTracer::~GCTracer() { |
| if (!FLAG_trace_gc) return; |
| // Printf ONE line iff flag is set. |
| PrintF("%s %.1f -> %.1f MB, %d ms.\n", |
| CollectorString(), |
| start_size_, SizeOfHeapObjects(), |
| static_cast<int>(OS::TimeCurrentMillis() - start_time_)); |
| |
| #if defined(ENABLE_LOGGING_AND_PROFILING) |
| Heap::PrintShortHeapStatistics(); |
| #endif |
| } |
| |
| |
| const char* GCTracer::CollectorString() { |
| switch (collector_) { |
| case SCAVENGER: |
| return "Scavenge"; |
| case MARK_COMPACTOR: |
| return MarkCompactCollector::HasCompacted() ? "Mark-compact" |
| : "Mark-sweep"; |
| } |
| return "Unknown GC"; |
| } |
| |
| |
| int KeyedLookupCache::Hash(Map* map, String* name) { |
| // Uses only lower 32 bits if pointers are larger. |
| uintptr_t addr_hash = |
| static_cast<uint32_t>(reinterpret_cast<uintptr_t>(map)) >> 2; |
| return (addr_hash ^ name->Hash()) % kLength; |
| } |
| |
| |
| int KeyedLookupCache::Lookup(Map* map, String* name) { |
| int index = Hash(map, name); |
| Key& key = keys_[index]; |
| if ((key.map == map) && key.name->Equals(name)) { |
| return field_offsets_[index]; |
| } |
| return -1; |
| } |
| |
| |
| void KeyedLookupCache::Update(Map* map, String* name, int field_offset) { |
| String* symbol; |
| if (Heap::LookupSymbolIfExists(name, &symbol)) { |
| int index = Hash(map, symbol); |
| Key& key = keys_[index]; |
| key.map = map; |
| key.name = symbol; |
| field_offsets_[index] = field_offset; |
| } |
| } |
| |
| |
| void KeyedLookupCache::Clear() { |
| for (int index = 0; index < kLength; index++) keys_[index].map = NULL; |
| } |
| |
| |
| KeyedLookupCache::Key KeyedLookupCache::keys_[KeyedLookupCache::kLength]; |
| |
| |
| int KeyedLookupCache::field_offsets_[KeyedLookupCache::kLength]; |
| |
| |
| void DescriptorLookupCache::Clear() { |
| for (int index = 0; index < kLength; index++) keys_[index].array = NULL; |
| } |
| |
| |
| DescriptorLookupCache::Key |
| DescriptorLookupCache::keys_[DescriptorLookupCache::kLength]; |
| |
| int DescriptorLookupCache::results_[DescriptorLookupCache::kLength]; |
| |
| |
| #ifdef DEBUG |
| bool Heap::GarbageCollectionGreedyCheck() { |
| ASSERT(FLAG_gc_greedy); |
| if (Bootstrapper::IsActive()) return true; |
| if (disallow_allocation_failure()) return true; |
| return CollectGarbage(0, NEW_SPACE); |
| } |
| #endif |
| |
| |
| TranscendentalCache::TranscendentalCache(TranscendentalCache::Type t) |
| : type_(t) { |
| uint32_t in0 = 0xffffffffu; // Bit-pattern for a NaN that isn't |
| uint32_t in1 = 0xffffffffu; // generated by the FPU. |
| for (int i = 0; i < kCacheSize; i++) { |
| elements_[i].in[0] = in0; |
| elements_[i].in[1] = in1; |
| elements_[i].output = NULL; |
| } |
| } |
| |
| |
| TranscendentalCache* TranscendentalCache::caches_[kNumberOfCaches]; |
| |
| |
| void TranscendentalCache::Clear() { |
| for (int i = 0; i < kNumberOfCaches; i++) { |
| if (caches_[i] != NULL) { |
| delete caches_[i]; |
| caches_[i] = NULL; |
| } |
| } |
| } |
| |
| |
| } } // namespace v8::internal |