| // Copyright 2006-2008 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 "debug.h" |
| #include "global-handles.h" |
| #include "jsregexp.h" |
| #include "mark-compact.h" |
| #include "natives.h" |
| #include "scanner.h" |
| #include "scopeinfo.h" |
| #include "v8threads.h" |
| |
| namespace v8 { namespace internal { |
| |
| #ifdef DEBUG |
| DEFINE_bool(gc_greedy, false, "perform GC prior to some allocations"); |
| DEFINE_bool(gc_verbose, false, "print stuff during garbage collection"); |
| DEFINE_bool(heap_stats, false, "report heap statistics before and after GC"); |
| DEFINE_bool(code_stats, false, "report code statistics after GC"); |
| DEFINE_bool(verify_heap, false, "verify heap pointers before and after GC"); |
| DEFINE_bool(print_handles, false, "report handles after GC"); |
| DEFINE_bool(print_global_handles, false, "report global handles after GC"); |
| DEFINE_bool(print_rset, false, "print remembered sets before GC"); |
| #endif |
| |
| DEFINE_int(new_space_size, 0, "size of (each semispace in) the new generation"); |
| DEFINE_int(old_space_size, 0, "size of the old generation"); |
| |
| DEFINE_bool(gc_global, false, "always perform global GCs"); |
| DEFINE_int(gc_interval, -1, "garbage collect after <n> allocations"); |
| DEFINE_bool(trace_gc, false, |
| "print one trace line following each garbage collection"); |
| |
| |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| DECLARE_bool(log_gc); |
| #endif |
| |
| |
| #define ROOT_ALLOCATION(type, name) type* Heap::name##_; |
| ROOT_LIST(ROOT_ALLOCATION) |
| #undef ROOT_ALLOCATION |
| |
| |
| #define STRUCT_ALLOCATION(NAME, Name, name) Map* Heap::name##_map_; |
| STRUCT_LIST(STRUCT_ALLOCATION) |
| #undef STRUCT_ALLOCATION |
| |
| |
| #define SYMBOL_ALLOCATION(name, string) String* Heap::name##_; |
| SYMBOL_LIST(SYMBOL_ALLOCATION) |
| #undef SYMBOL_ALLOCATION |
| |
| |
| NewSpace* Heap::new_space_ = NULL; |
| OldSpace* Heap::old_pointer_space_ = NULL; |
| OldSpace* Heap::old_data_space_ = NULL; |
| OldSpace* Heap::code_space_ = NULL; |
| MapSpace* Heap::map_space_ = NULL; |
| LargeObjectSpace* Heap::lo_space_ = NULL; |
| |
| int Heap::promoted_space_limit_ = 0; |
| 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. |
| int Heap::semispace_size_ = 1*MB; |
| int Heap::old_generation_size_ = 512*MB; |
| int Heap::initial_semispace_size_ = 256*KB; |
| |
| 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_. |
| |
| // Double the new space after this many scavenge collections. |
| int Heap::new_space_growth_limit_ = 8; |
| int Heap::scavenge_count_ = 0; |
| Heap::HeapState Heap::gc_state_ = NOT_IN_GC; |
| |
| int Heap::mc_count_ = 0; |
| int Heap::gc_count_ = 0; |
| |
| #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(); |
| } |
| |
| |
| 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(); |
| } |
| |
| |
| bool Heap::HasBeenSetup() { |
| return new_space_ != NULL && |
| old_pointer_space_ != NULL && |
| old_data_space_ != NULL && |
| code_space_ != NULL && |
| map_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 (PromotedSpaceSize() + PromotedExternalMemorySize() |
| > promoted_space_limit_) { |
| 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 |
| } |
| |
| |
| // 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) { |
| 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() { |
| RegExpImpl::NewSpaceCollectionPrologue(); |
| 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()); |
| |
| SymbolTable* symbol_table = SymbolTable::cast(Heap::symbol_table_); |
| 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 |
| } |
| |
| |
| void Heap::CollectAllGarbage() { |
| // 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. |
| CollectGarbage(0, OLD_POINTER_SPACE); |
| } |
| |
| |
| 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); |
| |
| StatsRate* 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 LO_SPACE: |
| return lo_space_->Available() >= requested_size; |
| } |
| return false; |
| } |
| |
| |
| void Heap::PerformScavenge() { |
| GCTracer tracer; |
| PerformGarbageCollection(NEW_SPACE, SCAVENGER, &tracer); |
| } |
| |
| |
| void Heap::PerformGarbageCollection(AllocationSpace space, |
| GarbageCollector collector, |
| GCTracer* tracer) { |
| if (collector == MARK_COMPACTOR && global_gc_prologue_callback_) { |
| ASSERT(!allocation_allowed_); |
| global_gc_prologue_callback_(); |
| } |
| |
| if (collector == MARK_COMPACTOR) { |
| MarkCompact(tracer); |
| |
| int promoted_space_size = PromotedSpaceSize(); |
| promoted_space_limit_ = |
| promoted_space_size + Max(2 * MB, (promoted_space_size/100) * 35); |
| old_gen_exhausted_ = false; |
| |
| // If we have used the mark-compact collector to collect the new |
| // space, and it has not compacted the new space, we force a |
| // separate scavenge collection. This is a hack. It covers the |
| // case where (1) a new space collection was requested, (2) the |
| // collector selection policy selected the mark-compact collector, |
| // and (3) the mark-compact collector policy selected not to |
| // compact the new space. In that case, there is no more (usable) |
| // free space in the new space after the collection compared to |
| // before. |
| if (space == NEW_SPACE && !MarkCompactCollector::HasCompacted()) { |
| Scavenge(); |
| } |
| } else { |
| Scavenge(); |
| } |
| Counters::objs_since_last_young.Set(0); |
| |
| // Process weak handles post gc. |
| GlobalHandles::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_(); |
| } |
| } |
| |
| |
| void Heap::MarkCompact(GCTracer* tracer) { |
| gc_state_ = MARK_COMPACT; |
| mc_count_++; |
| tracer->set_full_gc_count(mc_count_); |
| LOG(ResourceEvent("markcompact", "begin")); |
| |
| MarkCompactPrologue(); |
| |
| MarkCompactCollector::CollectGarbage(tracer); |
| |
| MarkCompactEpilogue(); |
| |
| LOG(ResourceEvent("markcompact", "end")); |
| |
| gc_state_ = NOT_IN_GC; |
| |
| Shrink(); |
| |
| Counters::objs_since_last_full.Set(0); |
| } |
| |
| |
| void Heap::MarkCompactPrologue() { |
| // Empty eval caches |
| Heap::eval_cache_global_ = Heap::null_value(); |
| Heap::eval_cache_non_global_ = Heap::null_value(); |
| |
| RegExpImpl::OldSpaceCollectionPrologue(); |
| Top::MarkCompactPrologue(); |
| ThreadManager::MarkCompactPrologue(); |
| } |
| |
| |
| void Heap::MarkCompactEpilogue() { |
| Top::MarkCompactEpilogue(); |
| ThreadManager::MarkCompactEpilogue(); |
| } |
| |
| |
| 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 CopyVisitor: public ObjectVisitor { |
| public: |
| |
| void VisitPointer(Object** p) { |
| CopyObject(p); |
| } |
| |
| void VisitPointers(Object** start, Object** end) { |
| // Copy all HeapObject pointers in [start, end) |
| for (Object** p = start; p < end; p++) CopyObject(p); |
| } |
| |
| private: |
| void CopyObject(Object** p) { |
| if (!Heap::InFromSpace(*p)) return; |
| Heap::CopyObject(reinterpret_cast<HeapObject**>(p)); |
| } |
| }; |
| |
| |
| // Shared state read by the scavenge collector and set by CopyObject. |
| static Address promoted_top = NULL; |
| |
| |
| #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))); |
| } |
| } |
| } |
| }; |
| #endif |
| |
| void Heap::Scavenge() { |
| #ifdef DEBUG |
| if (FLAG_enable_slow_asserts) { |
| VerifyNonPointerSpacePointersVisitor v; |
| HeapObjectIterator it(code_space_); |
| while (it.has_next()) { |
| HeapObject* object = it.next(); |
| if (object->IsCode()) { |
| Code::cast(object)->ConvertICTargetsFromAddressToObject(); |
| } |
| object->Iterate(&v); |
| if (object->IsCode()) { |
| Code::cast(object)->ConvertICTargetsFromObjectToAddress(); |
| } |
| } |
| } |
| #endif |
| |
| gc_state_ = SCAVENGE; |
| |
| // Implements Cheney's copying algorithm |
| LOG(ResourceEvent("scavenge", "begin")); |
| |
| scavenge_count_++; |
| if (new_space_->Capacity() < new_space_->MaximumCapacity() && |
| scavenge_count_ > new_space_growth_limit_) { |
| // Double the size of the new space, and double the limit. The next |
| // doubling attempt will occur after the current new_space_growth_limit_ |
| // more collections. |
| // TODO(1240712): NewSpace::Double has a return value which is |
| // ignored here. |
| new_space_->Double(); |
| new_space_growth_limit_ *= 2; |
| } |
| |
| // 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 in either the to space |
| // or the old space. For to space objects, we use a mark. Newly copied |
| // objects lie between the mark and the allocation top. For objects |
| // promoted to old space, we write their addresses downward from the top of |
| // the new space. Sweeping newly promoted objects requires an allocation |
| // pointer and a mark. Note that the allocation pointer 'top' actually |
| // moves downward from the high address in the to space. |
| // |
| // 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. Using the new space to record promoted addresses makes the |
| // scavenge collector agnostic to the allocation strategy (eg, linear or |
| // free-list) used in old space. |
| Address new_mark = new_space_->ToSpaceLow(); |
| Address promoted_mark = new_space_->ToSpaceHigh(); |
| promoted_top = new_space_->ToSpaceHigh(); |
| |
| CopyVisitor copy_visitor; |
| // Copy roots. |
| IterateRoots(©_visitor); |
| |
| // Copy objects reachable from the old generation. By definition, there |
| // are no intergenerational pointers in code or data spaces. |
| IterateRSet(old_pointer_space_, &CopyObject); |
| IterateRSet(map_space_, &CopyObject); |
| lo_space_->IterateRSet(&CopyObject); |
| |
| bool has_processed_weak_pointers = false; |
| |
| while (true) { |
| ASSERT(new_mark <= new_space_->top()); |
| ASSERT(promoted_mark >= promoted_top); |
| |
| // Copy objects reachable from newly copied objects. |
| while (new_mark < new_space_->top() || promoted_mark > promoted_top) { |
| // Sweep newly copied objects in the to space. The allocation pointer |
| // can change during sweeping. |
| Address previous_top = new_space_->top(); |
| SemiSpaceIterator new_it(new_space_, new_mark); |
| while (new_it.has_next()) { |
| new_it.next()->Iterate(©_visitor); |
| } |
| new_mark = previous_top; |
| |
| // Sweep newly copied objects in the old space. The promotion 'top' |
| // pointer could change during sweeping. |
| previous_top = promoted_top; |
| for (Address current = promoted_mark - kPointerSize; |
| current >= previous_top; |
| current -= kPointerSize) { |
| HeapObject* object = HeapObject::cast(Memory::Object_at(current)); |
| object->Iterate(©_visitor); |
| UpdateRSet(object); |
| } |
| promoted_mark = previous_top; |
| } |
| |
| if (has_processed_weak_pointers) break; // We are done. |
| // Copy objects reachable from weak pointers. |
| GlobalHandles::IterateWeakRoots(©_visitor); |
| has_processed_weak_pointers = true; |
| } |
| |
| // Set age mark. |
| new_space_->set_age_mark(new_mark); |
| |
| 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. |
| 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 or data |
| // 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_p, |
| HeapObject* target, |
| int size) { |
| void** src = reinterpret_cast<void**>((*source_p)->address()); |
| void** dst = reinterpret_cast<void**>(target->address()); |
| int counter = size/kPointerSize - 1; |
| do { |
| *dst++ = *src++; |
| } while (counter-- > 0); |
| |
| // Set the forwarding address. |
| (*source_p)->set_map_word(MapWord::FromForwardingAddress(target)); |
| |
| // Update NewSpace stats if necessary. |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| RecordCopiedObject(target); |
| #endif |
| |
| return target; |
| } |
| |
| |
| void Heap::CopyObject(HeapObject** p) { |
| ASSERT(InFromSpace(*p)); |
| |
| HeapObject* object = *p; |
| |
| // We use the first word (where the map pointer usually is) of a heap |
| // object to record the forwarding pointer. A forwarding pointer can |
| // point to an old space, the code space, or the to space of the new |
| // generation. |
| MapWord first_word = object->map_word(); |
| |
| // If the first word is a forwarding address, the object has already been |
| // copied. |
| if (first_word.IsForwardingAddress()) { |
| *p = first_word.ToForwardingAddress(); |
| return; |
| } |
| |
| // Optimization: Bypass ConsString objects where the right-hand side is |
| // Heap::empty_string(). We do not use object->IsConsString because we |
| // already know that object has the heap object tag. |
| InstanceType type = first_word.ToMap()->instance_type(); |
| if (type < FIRST_NONSTRING_TYPE && |
| String::cast(object)->representation_tag() == kConsStringTag && |
| ConsString::cast(object)->second() == Heap::empty_string()) { |
| object = HeapObject::cast(ConsString::cast(object)->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 (!InFromSpace(object)) return; |
| first_word = object->map_word(); |
| if (first_word.IsForwardingAddress()) { |
| *p = first_word.ToForwardingAddress(); |
| return; |
| } |
| type = first_word.ToMap()->instance_type(); |
| } |
| |
| int object_size = object->SizeFromMap(first_word.ToMap()); |
| Object* result; |
| // If the object should be promoted, we try to copy it to old space. |
| if (ShouldBePromoted(object->address(), object_size)) { |
| 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()) { |
| *p = MigrateObject(p, HeapObject::cast(result), object_size); |
| if (target_space == Heap::old_pointer_space_) { |
| // Record the object's address at the top of the to space, to allow |
| // it to be swept by the scavenger. |
| promoted_top -= kPointerSize; |
| Memory::Object_at(promoted_top) = *p; |
| } else { |
| #ifdef DEBUG |
| // Objects promoted to the data space should not have pointers to |
| // new space. |
| VerifyNonPointerSpacePointersVisitor v; |
| (*p)->Iterate(&v); |
| #endif |
| } |
| return; |
| } |
| } |
| |
| // The object should remain in new space or the old space allocation failed. |
| result = new_space_->AllocateRaw(object_size); |
| // Failed allocation at this point is utterly unexpected. |
| ASSERT(!result->IsFailure()); |
| *p = MigrateObject(p, HeapObject::cast(result), object_size); |
| } |
| |
| |
| Object* Heap::AllocatePartialMap(InstanceType instance_type, |
| int instance_size) { |
| Object* result = AllocateRawMap(Map::kSize); |
| if (result->IsFailure()) return result; |
| |
| // Map::cast cannot be used due to uninitialized map field. |
| reinterpret_cast<Map*>(result)->set_map(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_unused_property_fields(0); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateMap(InstanceType instance_type, int instance_size) { |
| Object* result = AllocateRawMap(Map::kSize); |
| 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_instance_descriptors(empty_descriptor_array()); |
| map->set_code_cache(empty_fixed_array()); |
| map->set_unused_property_fields(0); |
| map->set_bit_field(0); |
| return map; |
| } |
| |
| |
| 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. |
| meta_map_ = reinterpret_cast<Map*>(obj); |
| meta_map()->set_map(meta_map()); |
| |
| obj = AllocatePartialMap(FIXED_ARRAY_TYPE, Array::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| fixed_array_map_ = Map::cast(obj); |
| |
| obj = AllocatePartialMap(ODDBALL_TYPE, Oddball::kSize); |
| if (obj->IsFailure()) return false; |
| oddball_map_ = Map::cast(obj); |
| |
| // Allocate the empty array |
| obj = AllocateEmptyFixedArray(); |
| if (obj->IsFailure()) return false; |
| empty_fixed_array_ = FixedArray::cast(obj); |
| |
| obj = Allocate(oddball_map(), OLD_DATA_SPACE); |
| if (obj->IsFailure()) return false; |
| null_value_ = obj; |
| |
| // Allocate the empty descriptor array. AllocateMap can now be used. |
| obj = AllocateEmptyFixedArray(); |
| if (obj->IsFailure()) return false; |
| // There is a check against empty_descriptor_array() in cast(). |
| empty_descriptor_array_ = reinterpret_cast<DescriptorArray*>(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; |
| heap_number_map_ = Map::cast(obj); |
| |
| obj = AllocateMap(PROXY_TYPE, Proxy::kSize); |
| if (obj->IsFailure()) return false; |
| proxy_map_ = Map::cast(obj); |
| |
| #define ALLOCATE_STRING_MAP(type, size, name) \ |
| obj = AllocateMap(type, size); \ |
| if (obj->IsFailure()) return false; \ |
| name##_map_ = Map::cast(obj); |
| STRING_TYPE_LIST(ALLOCATE_STRING_MAP); |
| #undef ALLOCATE_STRING_MAP |
| |
| obj = AllocateMap(SHORT_STRING_TYPE, TwoByteString::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| undetectable_short_string_map_ = Map::cast(obj); |
| undetectable_short_string_map_->set_is_undetectable(); |
| |
| obj = AllocateMap(MEDIUM_STRING_TYPE, TwoByteString::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| undetectable_medium_string_map_ = Map::cast(obj); |
| undetectable_medium_string_map_->set_is_undetectable(); |
| |
| obj = AllocateMap(LONG_STRING_TYPE, TwoByteString::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| undetectable_long_string_map_ = Map::cast(obj); |
| undetectable_long_string_map_->set_is_undetectable(); |
| |
| obj = AllocateMap(SHORT_ASCII_STRING_TYPE, AsciiString::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| undetectable_short_ascii_string_map_ = Map::cast(obj); |
| undetectable_short_ascii_string_map_->set_is_undetectable(); |
| |
| obj = AllocateMap(MEDIUM_ASCII_STRING_TYPE, AsciiString::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| undetectable_medium_ascii_string_map_ = Map::cast(obj); |
| undetectable_medium_ascii_string_map_->set_is_undetectable(); |
| |
| obj = AllocateMap(LONG_ASCII_STRING_TYPE, AsciiString::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| undetectable_long_ascii_string_map_ = Map::cast(obj); |
| undetectable_long_ascii_string_map_->set_is_undetectable(); |
| |
| obj = AllocateMap(BYTE_ARRAY_TYPE, Array::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| byte_array_map_ = Map::cast(obj); |
| |
| obj = AllocateMap(CODE_TYPE, Code::kHeaderSize); |
| if (obj->IsFailure()) return false; |
| code_map_ = Map::cast(obj); |
| |
| obj = AllocateMap(FILLER_TYPE, kPointerSize); |
| if (obj->IsFailure()) return false; |
| one_word_filler_map_ = Map::cast(obj); |
| |
| obj = AllocateMap(FILLER_TYPE, 2 * kPointerSize); |
| if (obj->IsFailure()) return false; |
| two_word_filler_map_ = Map::cast(obj); |
| |
| #define ALLOCATE_STRUCT_MAP(NAME, Name, name) \ |
| obj = AllocateMap(NAME##_TYPE, Name::kSize); \ |
| if (obj->IsFailure()) return false; \ |
| name##_map_ = Map::cast(obj); |
| STRUCT_LIST(ALLOCATE_STRUCT_MAP) |
| #undef ALLOCATE_STRUCT_MAP |
| |
| obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kSize); |
| if (obj->IsFailure()) return false; |
| hash_table_map_ = Map::cast(obj); |
| |
| obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kSize); |
| if (obj->IsFailure()) return false; |
| context_map_ = Map::cast(obj); |
| |
| obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kSize); |
| if (obj->IsFailure()) return false; |
| global_context_map_ = Map::cast(obj); |
| |
| obj = AllocateMap(JS_FUNCTION_TYPE, JSFunction::kSize); |
| if (obj->IsFailure()) return false; |
| boilerplate_function_map_ = Map::cast(obj); |
| |
| obj = AllocateMap(SHARED_FUNCTION_INFO_TYPE, SharedFunctionInfo::kSize); |
| if (obj->IsFailure()) return false; |
| 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); |
| 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) { |
| // 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::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; |
| 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)); |
| message_listeners_ = JSObject::cast(obj); |
| |
| obj = Heap::AllocateJSObjectFromMap(neander_map_); |
| if (obj->IsFailure()) return false; |
| elements = AllocateFixedArray(2); |
| if (elements->IsFailure()) return false; |
| FixedArray::cast(elements)->set(0, Smi::FromInt(0)); |
| JSObject::cast(obj)->set_elements(FixedArray::cast(elements)); |
| debug_event_listeners_ = JSObject::cast(obj); |
| |
| return true; |
| } |
| |
| 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; |
| { |
| CEntryStub stub; |
| c_entry_code_ = *stub.GetCode(); |
| } |
| { |
| CEntryDebugBreakStub stub; |
| c_entry_debug_break_code_ = *stub.GetCode(); |
| } |
| { |
| JSEntryStub stub; |
| js_entry_code_ = *stub.GetCode(); |
| } |
| { |
| JSConstructEntryStub stub; |
| js_construct_entry_code_ = *stub.GetCode(); |
| } |
| } |
| |
| |
| bool Heap::CreateInitialObjects() { |
| Object* obj; |
| |
| // The -0 value must be set before NumberFromDouble works. |
| obj = AllocateHeapNumber(-0.0, TENURED); |
| if (obj->IsFailure()) return false; |
| minus_zero_value_ = obj; |
| ASSERT(signbit(minus_zero_value_->Number()) != 0); |
| |
| obj = AllocateHeapNumber(OS::nan_value(), TENURED); |
| if (obj->IsFailure()) return false; |
| nan_value_ = obj; |
| |
| obj = Allocate(oddball_map(), OLD_DATA_SPACE); |
| if (obj->IsFailure()) return false; |
| undefined_value_ = obj; |
| ASSERT(!InNewSpace(undefined_value())); |
| |
| // Allocate initial symbol table. |
| obj = SymbolTable::Allocate(kInitialSymbolTableSize); |
| if (obj->IsFailure()) return false; |
| symbol_table_ = 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; |
| true_value_ = obj; |
| |
| obj = CreateOddball(oddball_map(), "false", Smi::FromInt(0)); |
| if (obj->IsFailure()) return false; |
| false_value_ = obj; |
| |
| obj = CreateOddball(oddball_map(), "hole", Smi::FromInt(-1)); |
| if (obj->IsFailure()) return false; |
| the_hole_value_ = obj; |
| |
| // Allocate the empty string. |
| obj = AllocateRawAsciiString(0, TENURED); |
| if (obj->IsFailure()) return false; |
| empty_string_ = String::cast(obj); |
| |
| #define SYMBOL_INITIALIZE(name, string) \ |
| obj = LookupAsciiSymbol(string); \ |
| if (obj->IsFailure()) return false; \ |
| (name##_) = String::cast(obj); |
| SYMBOL_LIST(SYMBOL_INITIALIZE) |
| #undef SYMBOL_INITIALIZE |
| |
| // Allocate the proxy for __proto__. |
| obj = AllocateProxy((Address) &Accessors::ObjectPrototype); |
| if (obj->IsFailure()) return false; |
| prototype_accessors_ = Proxy::cast(obj); |
| |
| // Allocate the code_stubs dictionary. |
| obj = Dictionary::Allocate(4); |
| if (obj->IsFailure()) return false; |
| code_stubs_ = Dictionary::cast(obj); |
| |
| // Allocate the non_monomorphic_cache used in stub-cache.cc |
| obj = Dictionary::Allocate(4); |
| if (obj->IsFailure()) return false; |
| non_monomorphic_cache_ = Dictionary::cast(obj); |
| |
| CreateFixedStubs(); |
| |
| // Allocate the number->string conversion cache |
| obj = AllocateFixedArray(kNumberStringCacheSize * 2); |
| if (obj->IsFailure()) return false; |
| number_string_cache_ = FixedArray::cast(obj); |
| |
| // Allocate cache for single character strings. |
| obj = AllocateFixedArray(String::kMaxAsciiCharCode+1); |
| if (obj->IsFailure()) return false; |
| 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; |
| natives_source_cache_ = FixedArray::cast(obj); |
| |
| // Initialized eval cache to null value. |
| eval_cache_global_ = null_value(); |
| eval_cache_non_global_ = null_value(); |
| |
| 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, FixedArray::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(), NEW_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); |
| 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_lazy_load_data(undefined_value()); |
| share->set_script(undefined_value()); |
| share->set_start_position_and_type(0); |
| share->set_debug_info(undefined_value()); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateConsString(String* first, String* second) { |
| int length = first->length() + second->length(); |
| bool is_ascii = first->is_ascii() && second->is_ascii(); |
| |
| // If the resulting string is small make a flat string. |
| if (length < ConsString::kMinLength) { |
| Object* result = is_ascii |
| ? AllocateRawAsciiString(length) |
| : AllocateRawTwoByteString(length); |
| if (result->IsFailure()) return result; |
| // Copy the characters into the new object. |
| String* string_result = String::cast(result); |
| int first_length = first->length(); |
| // Copy the content of the first string. |
| for (int i = 0; i < first_length; i++) { |
| string_result->Set(i, first->Get(i)); |
| } |
| int second_length = second->length(); |
| // Copy the content of the first string. |
| for (int i = 0; i < second_length; i++) { |
| string_result->Set(first_length + i, second->Get(i)); |
| } |
| 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; |
| |
| ConsString* cons_string = ConsString::cast(result); |
| cons_string->set_first(first); |
| cons_string->set_second(second); |
| 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 (end - start <= SlicedString::kMinLength) { |
| return Heap::AllocateSubString(buffer, start, end); |
| } |
| |
| Map* map; |
| if (length <= String::kMaxShortStringSize) { |
| map = buffer->is_ascii() ? short_sliced_ascii_string_map() |
| : short_sliced_string_map(); |
| } else if (length <= String::kMaxMediumStringSize) { |
| map = buffer->is_ascii() ? medium_sliced_ascii_string_map() |
| : medium_sliced_string_map(); |
| } else { |
| map = buffer->is_ascii() ? 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; |
| |
| // Make an attempt to flatten the buffer to reduce access time. |
| buffer->TryFlatten(); |
| |
| Object* result = buffer->is_ascii() |
| ? AllocateRawAsciiString(length) |
| : AllocateRawTwoByteString(length); |
| if (result->IsFailure()) return result; |
| |
| // Copy the characters into the new object. |
| String* string_result = String::cast(result); |
| for (int i = 0; i < length; i++) { |
| string_result->Set(i, buffer->Get(start + i)); |
| } |
| 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) { |
| Map* map; |
| int length = resource->length(); |
| if (length <= String::kMaxShortStringSize) { |
| map = short_external_string_map(); |
| } else if (length <= String::kMaxMediumStringSize) { |
| map = medium_external_string_map(); |
| } else { |
| map = long_external_string_map(); |
| } |
| |
| 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; |
| Object* result = Heap::AllocateRawAsciiString(1); |
| if (result->IsFailure()) return result; |
| String::cast(result)->Set(0, code); |
| Heap::single_character_string_cache()->set(code, result); |
| return result; |
| } |
| Object* result = Heap::AllocateRawTwoByteString(1); |
| if (result->IsFailure()) return result; |
| String::cast(result)->Set(0, code); |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateByteArray(int length) { |
| int size = ByteArray::SizeFor(length); |
| AllocationSpace space = |
| size > MaxHeapObjectSize() ? LO_SPACE : NEW_SPACE; |
| |
| Object* result = AllocateRaw(size, 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::CreateCode(const CodeDesc& desc, |
| ScopeInfo<>* sinfo, |
| Code::Flags flags) { |
| // 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); |
| Object* result; |
| if (obj_size > MaxHeapObjectSize()) { |
| 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); |
| code->set_ic_flag(Code::IC_TARGET_IS_ADDRESS); |
| code->CopyFrom(desc); // migrate generated code |
| 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 > MaxHeapObjectSize()) { |
| 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(); |
| memcpy(new_addr, 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); |
| 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()); |
| return function; |
| } |
| |
| |
| Object* Heap::AllocateFunctionPrototype(JSFunction* function) { |
| // Allocate the prototype. |
| Object* prototype = |
| AllocateJSObject(Top::context()->global_context()->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(); |
| Object* result = boilerplate->Copy(); |
| if (result->IsFailure()) return result; |
| |
| Object* obj = JSObject::cast(result)->properties(); |
| FixedArray::cast(obj)->set(arguments_callee_index, callee); |
| FixedArray::cast(obj)->set(arguments_length_index, Smi::FromInt(length)); |
| |
| // Allocate the fixed array. |
| obj = Heap::AllocateFixedArray(length); |
| if (obj->IsFailure()) return obj; |
| JSObject::cast(result)->set_elements(FixedArray::cast(obj)); |
| |
| // 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. |
| Object* map_obj = Heap::AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize); |
| 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_unused_property_fields(fun->shared()->expected_nof_properties()); |
| map->set_prototype(prototype); |
| 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); |
| |
| // Allocate the backing storage for the properties. |
| Object* properties = AllocateFixedArray(map->unused_property_fields()); |
| if (properties->IsFailure()) return properties; |
| |
| // Allocate the JSObject. |
| AllocationSpace space = |
| (pretenure == TENURED) ? OLD_POINTER_SPACE : NEW_SPACE; |
| if (map->instance_size() > MaxHeapObjectSize()) 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. |
| return AllocateJSObjectFromMap(constructor->initial_map(), pretenure); |
| } |
| |
| |
| Object* Heap::ReinitializeJSGlobalObject(JSFunction* constructor, |
| JSGlobalObject* 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. |
| Object* properties = AllocateFixedArray(map->unused_property_fields()); |
| 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. |
| AsciiString* string_result = AsciiString::cast(result); |
| for (int i = 0; i < string.length(); i++) { |
| string_result->AsciiStringSet(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 short_sliced_symbol_map(); |
| if (map == long_sliced_string_map()) return short_sliced_symbol_map(); |
| |
| if (map == short_sliced_ascii_string_map()) { |
| return short_sliced_ascii_symbol_map(); |
| } |
| if (map == medium_sliced_ascii_string_map()) { |
| return short_sliced_ascii_symbol_map(); |
| } |
| if (map == long_sliced_ascii_string_map()) { |
| return short_sliced_ascii_symbol_map(); |
| } |
| |
| if (map == short_external_string_map()) return short_external_string_map(); |
| if (map == medium_external_string_map()) return medium_external_string_map(); |
| if (map == long_external_string_map()) return long_external_string_map(); |
| |
| if (map == short_external_ascii_string_map()) { |
| return short_external_ascii_string_map(); |
| } |
| if (map == medium_external_ascii_string_map()) { |
| return medium_external_ascii_string_map(); |
| } |
| if (map == long_external_ascii_string_map()) { |
| return long_external_ascii_string_map(); |
| } |
| |
| // No match found. |
| return NULL; |
| } |
| |
| |
| Object* Heap::AllocateSymbol(unibrow::CharacterStream* buffer, |
| int chars, |
| int hash) { |
| // Ensure the chars matches the number of characters in the buffer. |
| ASSERT(static_cast<unsigned>(chars) == buffer->Length()); |
| // Determine whether the string is ascii. |
| bool is_ascii = true; |
| while (buffer->has_more()) { |
| if (buffer->GetNext() > unibrow::Utf8::kMaxOneByteChar) is_ascii = false; |
| } |
| 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 = AsciiString::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 = TwoByteString::SizeFor(chars); |
| } |
| |
| // Allocate string. |
| AllocationSpace space = |
| (size > MaxHeapObjectSize()) ? LO_SPACE : OLD_DATA_SPACE; |
| Object* result = AllocateRaw(size, space); |
| if (result->IsFailure()) return result; |
| |
| reinterpret_cast<HeapObject*>(result)->set_map(map); |
| // The hash value contains the length of the string. |
| String::cast(result)->set_length_field(hash); |
| |
| ASSERT_EQ(size, String::cast(result)->Size()); |
| |
| // Fill in the characters. |
| for (int i = 0; i < chars; i++) { |
| String::cast(result)->Set(i, buffer->GetNext()); |
| } |
| return result; |
| } |
| |
| |
| Object* Heap::AllocateRawAsciiString(int length, PretenureFlag pretenure) { |
| AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE; |
| int size = AsciiString::SizeFor(length); |
| if (size > MaxHeapObjectSize()) { |
| space = LO_SPACE; |
| } |
| |
| // Use AllocateRaw rather than Allocate because the object's size cannot be |
| // determined from the map. |
| Object* result = AllocateRaw(size, 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 = TwoByteString::SizeFor(length); |
| if (size > MaxHeapObjectSize()) { |
| space = LO_SPACE; |
| } |
| |
| // Use AllocateRaw rather than Allocate because the object's size cannot be |
| // determined from the map. |
| Object* result = AllocateRaw(size, 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); |
| 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::AllocateFixedArray(int length, PretenureFlag pretenure) { |
| ASSERT(empty_fixed_array()->IsFixedArray()); |
| if (length == 0) return empty_fixed_array(); |
| |
| int size = FixedArray::SizeFor(length); |
| Object* result; |
| if (size > MaxHeapObjectSize()) { |
| result = lo_space_->AllocateRawFixedArray(size); |
| } else { |
| AllocationSpace space = |
| (pretenure == TENURED) ? OLD_POINTER_SPACE : NEW_SPACE; |
| result = AllocateRaw(size, 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); |
| for (int index = 0; index < length; index++) array->set_undefined(index); |
| return array; |
| } |
| |
| |
| Object* Heap::AllocateFixedArrayWithHoles(int length) { |
| if (length == 0) return empty_fixed_array(); |
| int size = FixedArray::SizeFor(length); |
| Object* result = size > MaxHeapObjectSize() |
| ? lo_space_->AllocateRawFixedArray(size) |
| : AllocateRaw(size, NEW_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); |
| for (int index = 0; index < length; index++) array->set_the_hole(index); |
| return array; |
| } |
| |
| |
| 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->IsDictionary()); |
| 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) { |
| Object* result = Heap::AllocateFixedArray(Context::MIN_CONTEXT_SLOTS); |
| if (result->IsFailure()) return result; |
| Context* context = reinterpret_cast<Context*>(result); |
| context->set_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 > MaxHeapObjectSize()) ? LO_SPACE : OLD_POINTER_SPACE; |
| Object* result = Heap::Allocate(map, space); |
| if (result->IsFailure()) return result; |
| Struct::cast(result)->InitializeBody(size); |
| return result; |
| } |
| |
| |
| #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("promoted_space_limit_ %d\n", promoted_space_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("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) || |
| 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 LO_SPACE: |
| return lo_space_->SlowContains(addr); |
| } |
| |
| return false; |
| } |
| |
| |
| #ifdef DEBUG |
| void Heap::Verify() { |
| ASSERT(HasBeenSetup()); |
| |
| VerifyPointersVisitor visitor; |
| Heap::IterateRoots(&visitor); |
| |
| AllSpaces spaces; |
| while (Space* space = spaces.next()) { |
| space->Verify(); |
| } |
| } |
| #endif // DEBUG |
| |
| |
| Object* Heap::LookupSymbol(Vector<const char> string) { |
| Object* symbol = NULL; |
| Object* new_table = |
| SymbolTable::cast(symbol_table_)->LookupSymbol(string, &symbol); |
| if (new_table->IsFailure()) return new_table; |
| symbol_table_ = new_table; |
| ASSERT(symbol != NULL); |
| return symbol; |
| } |
| |
| |
| Object* Heap::LookupSymbol(String* string) { |
| if (string->IsSymbol()) return string; |
| Object* symbol = NULL; |
| Object* new_table = |
| SymbolTable::cast(symbol_table_)->LookupString(string, &symbol); |
| if (new_table->IsFailure()) return new_table; |
| symbol_table_ = new_table; |
| ASSERT(symbol != NULL); |
| return symbol; |
| } |
| |
| |
| Object* Heap::LookupEvalCache(bool is_global_context, String* src) { |
| Object* cache = is_global_context ? |
| eval_cache_global_ : eval_cache_non_global_; |
| return cache == null_value() ? |
| null_value() : EvalCache::cast(cache)->Lookup(src); |
| } |
| |
| |
| Object* Heap::PutInEvalCache(bool is_global_context, String* src, |
| JSFunction* value) { |
| Object** cache_ptr = is_global_context ? |
| &eval_cache_global_ : &eval_cache_non_global_; |
| |
| if (*cache_ptr == null_value()) { |
| Object* obj = EvalCache::Allocate(kInitialEvalCacheSize); |
| if (obj->IsFailure()) return false; |
| *cache_ptr = obj; |
| } |
| |
| Object* new_cache = |
| EvalCache::cast(*cache_ptr)->Put(src, value); |
| if (new_cache->IsFailure()) return new_cache; |
| *cache_ptr = new_cache; |
| |
| return value; |
| } |
| |
| |
| #ifdef DEBUG |
| void Heap::ZapFromSpace() { |
| ASSERT(HAS_HEAP_OBJECT_TAG(kFromSpaceZapValue)); |
| for (Address a = new_space_->FromSpaceLow(); |
| a < new_space_->FromSpaceHigh(); |
| a += kPointerSize) { |
| Memory::Address_at(a) = kFromSpaceZapValue; |
| } |
| } |
| #endif // DEBUG |
| |
| |
| void 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; |
| |
| // 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) { |
| // Bits were set. |
| uint32_t result_rset = rset_word; |
| |
| // Loop over all the bits in the remembered set word. Though |
| // remembered sets are sparse, faster (eg, binary) search for |
| // set bits does not seem to help much here. |
| for (int bit_offset = 0; bit_offset < kBitsPerInt; bit_offset++) { |
| uint32_t bitmask = 1 << bit_offset; |
| // 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::InFromSpace(*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::InToSpace(*object_p)) result_rset &= ~bitmask; |
| } |
| 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; |
| } |
| } |
| |
| |
| void Heap::IterateRSet(PagedSpace* space, ObjectSlotCallback copy_object_func) { |
| ASSERT(Page::is_rset_in_use()); |
| ASSERT(space == old_pointer_space_ || space == map_space_); |
| |
| PageIterator it(space, PageIterator::PAGES_IN_USE); |
| while (it.has_next()) { |
| Page* page = it.next(); |
| IterateRSetRange(page->ObjectAreaStart(), page->AllocationTop(), |
| page->RSetStart(), copy_object_func); |
| } |
| } |
| |
| |
| #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**>(&symbol_table_)); |
| SYNCHRONIZE_TAG("symbol_table"); |
| } |
| |
| |
| void Heap::IterateStrongRoots(ObjectVisitor* v) { |
| #define ROOT_ITERATE(type, name) \ |
| v->VisitPointer(reinterpret_cast<Object**>(&name##_)); |
| STRONG_ROOT_LIST(ROOT_ITERATE); |
| #undef ROOT_ITERATE |
| SYNCHRONIZE_TAG("strong_root_list"); |
| |
| #define STRUCT_MAP_ITERATE(NAME, Name, name) \ |
| v->VisitPointer(reinterpret_cast<Object**>(&name##_map_)); |
| STRUCT_LIST(STRUCT_MAP_ITERATE); |
| #undef STRUCT_MAP_ITERATE |
| SYNCHRONIZE_TAG("struct_map"); |
| |
| #define SYMBOL_ITERATE(name, string) \ |
| v->VisitPointer(reinterpret_cast<Object**>(&name##_)); |
| SYMBOL_LIST(SYMBOL_ITERATE) |
| #undef SYMBOL_ITERATE |
| SYNCHRONIZE_TAG("symbol"); |
| |
| Bootstrapper::Iterate(v); |
| SYNCHRONIZE_TAG("bootstrapper"); |
| Top::Iterate(v); |
| SYNCHRONIZE_TAG("top"); |
| Debug::Iterate(v); |
| SYNCHRONIZE_TAG("debug"); |
| |
| // 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_; |
| |
| // 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() |
| + 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 allocate an initial chunk of memory. The |
| // initial 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; |
| |
| // Put the initial chunk of the old space at the start of the initial |
| // chunk, then the two new space semispaces, then the initial chunk of |
| // code space. Align the pair of semispaces to their size, which must be |
| // a power of 2. |
| ASSERT(IsPowerOf2(young_generation_size_)); |
| Address old_space_start = reinterpret_cast<Address>(chunk); |
| Address new_space_start = RoundUp(old_space_start, young_generation_size_); |
| Address code_space_start = new_space_start + young_generation_size_; |
| int old_space_size = new_space_start - old_space_start; |
| int code_space_size = young_generation_size_ - old_space_size; |
| |
| // Initialize new space. |
| new_space_ = new NewSpace(initial_semispace_size_, |
| semispace_size_, |
| NEW_SPACE); |
| if (new_space_ == NULL) return false; |
| if (!new_space_->Setup(new_space_start, young_generation_size_)) return false; |
| |
| // Initialize old space, set the maximum capacity to the old generation |
| // size. It will not contain code. |
| 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(old_space_start, old_space_size >> 1)) { |
| return false; |
| } |
| 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(old_space_start + (old_space_size >> 1), |
| old_space_size >> 1)) { |
| 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(code_space_start, code_space_size)) return false; |
| |
| // Initialize map space. |
| map_space_ = new MapSpace(kMaxMapSpaceSize, MAP_SPACE); |
| if (map_space_ == NULL) return false; |
| // Setting up a paged space without giving it a virtual memory range big |
| // enough to hold at least a page will cause it to allocate. |
| if (!map_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::TearDown() { |
| GlobalHandles::TearDown(); |
| |
| if (new_space_ != NULL) { |
| new_space_->TearDown(); |
| delete new_space_; |
| new_space_ = NULL; |
| } |
| |
| 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 (lo_space_ != NULL) { |
| lo_space_->TearDown(); |
| delete lo_space_; |
| lo_space_ = NULL; |
| } |
| |
| MemoryAllocator::TearDown(); |
| } |
| |
| |
| void Heap::Shrink() { |
| // Try to shrink map, old, and code spaces. |
| map_space_->Shrink(); |
| old_pointer_space_->Shrink(); |
| old_data_space_->Shrink(); |
| code_space_->Shrink(); |
| } |
| |
| |
| #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 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(); |
| 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 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(); |
| } |
| |
| |
| // |
| // HeapProfiler class implementation. |
| // |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| void HeapProfiler::CollectStats(HeapObject* obj, HistogramInfo* info) { |
| InstanceType type = obj->map()->instance_type(); |
| ASSERT(0 <= type && type <= LAST_TYPE); |
| info[type].increment_number(1); |
| info[type].increment_bytes(obj->Size()); |
| } |
| #endif |
| |
| |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| void HeapProfiler::WriteSample() { |
| LOG(HeapSampleBeginEvent("Heap", "allocated")); |
| |
| HistogramInfo info[LAST_TYPE+1]; |
| #define DEF_TYPE_NAME(name) info[name].set_name(#name); |
| INSTANCE_TYPE_LIST(DEF_TYPE_NAME) |
| #undef DEF_TYPE_NAME |
| |
| HeapIterator iterator; |
| while (iterator.has_next()) { |
| CollectStats(iterator.next(), info); |
| } |
| |
| // Lump all the string types together. |
| int string_number = 0; |
| int string_bytes = 0; |
| #define INCREMENT_SIZE(type, size, name) \ |
| string_number += info[type].number(); \ |
| string_bytes += info[type].bytes(); |
| STRING_TYPE_LIST(INCREMENT_SIZE) |
| #undef INCREMENT_SIZE |
| if (string_bytes > 0) { |
| LOG(HeapSampleItemEvent("STRING_TYPE", string_number, string_bytes)); |
| } |
| |
| for (int i = FIRST_NONSTRING_TYPE; i <= LAST_TYPE; ++i) { |
| if (info[i].bytes() > 0) { |
| LOG(HeapSampleItemEvent(info[i].name(), info[i].number(), |
| info[i].bytes())); |
| } |
| } |
| |
| LOG(HeapSampleEndEvent("Heap", "allocated")); |
| } |
| |
| |
| #endif |
| |
| |
| |
| #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; |
| } |
| |
| if (obj->IsCode()) { |
| Code::cast(obj)->ConvertICTargetsFromAddressToObject(); |
| } |
| |
| // 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); |
| |
| if (obj->IsCode()) { |
| Code::cast(obj)->ConvertICTargetsFromObjectToAddress(); |
| } |
| } |
| |
| |
| 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_)); |
| } |
| |
| |
| const char* GCTracer::CollectorString() { |
| switch (collector_) { |
| case SCAVENGER: |
| return "Scavenge"; |
| case MARK_COMPACTOR: |
| return MarkCompactCollector::HasCompacted() ? "Mark-compact" |
| : "Mark-sweep"; |
| } |
| return "Unknown GC"; |
| } |
| |
| |
| } } // namespace v8::internal |