diff options
Diffstat (limited to 'deps/v8/src/spaces.cc')
| -rw-r--r-- | deps/v8/src/spaces.cc | 2936 |
1 files changed, 1195 insertions, 1741 deletions
diff --git a/deps/v8/src/spaces.cc b/deps/v8/src/spaces.cc index 97c6d2ac19..61b318118a 100644 --- a/deps/v8/src/spaces.cc +++ b/deps/v8/src/spaces.cc @@ -35,52 +35,66 @@ namespace v8 { namespace internal { -// For contiguous spaces, top should be in the space (or at the end) and limit -// should be the end of the space. -#define ASSERT_SEMISPACE_ALLOCATION_INFO(info, space) \ - ASSERT((space).low() <= (info).top \ - && (info).top <= (space).high() \ - && (info).limit == (space).high()) // ---------------------------------------------------------------------------- // HeapObjectIterator HeapObjectIterator::HeapObjectIterator(PagedSpace* space) { - Initialize(space->bottom(), space->top(), NULL); + // You can't actually iterate over the anchor page. It is not a real page, + // just an anchor for the double linked page list. Initialize as if we have + // reached the end of the anchor page, then the first iteration will move on + // to the first page. + Initialize(space, + NULL, + NULL, + kAllPagesInSpace, + NULL); } HeapObjectIterator::HeapObjectIterator(PagedSpace* space, HeapObjectCallback size_func) { - Initialize(space->bottom(), space->top(), size_func); -} - - -HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start) { - Initialize(start, space->top(), NULL); -} - - -HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start, - HeapObjectCallback size_func) { - Initialize(start, space->top(), size_func); + // You can't actually iterate over the anchor page. It is not a real page, + // just an anchor for the double linked page list. Initialize the current + // address and end as NULL, then the first iteration will move on + // to the first page. + Initialize(space, + NULL, + NULL, + kAllPagesInSpace, + size_func); } HeapObjectIterator::HeapObjectIterator(Page* page, HeapObjectCallback size_func) { - Initialize(page->ObjectAreaStart(), page->AllocationTop(), size_func); -} - - -void HeapObjectIterator::Initialize(Address cur, Address end, + Space* owner = page->owner(); + ASSERT(owner == HEAP->old_pointer_space() || + owner == HEAP->old_data_space() || + owner == HEAP->map_space() || + owner == HEAP->cell_space() || + owner == HEAP->code_space()); + Initialize(reinterpret_cast<PagedSpace*>(owner), + page->ObjectAreaStart(), + page->ObjectAreaEnd(), + kOnePageOnly, + size_func); + ASSERT(page->WasSweptPrecisely()); +} + + +void HeapObjectIterator::Initialize(PagedSpace* space, + Address cur, Address end, + HeapObjectIterator::PageMode mode, HeapObjectCallback size_f) { + // Check that we actually can iterate this space. + ASSERT(!space->was_swept_conservatively()); + + space_ = space; cur_addr_ = cur; - end_addr_ = end; - end_page_ = Page::FromAllocationTop(end); + cur_end_ = end; + page_mode_ = mode; size_func_ = size_f; - Page* p = Page::FromAllocationTop(cur_addr_); - cur_limit_ = (p == end_page_) ? end_addr_ : p->AllocationTop(); #ifdef DEBUG Verify(); @@ -88,63 +102,35 @@ void HeapObjectIterator::Initialize(Address cur, Address end, } -HeapObject* HeapObjectIterator::FromNextPage() { - if (cur_addr_ == end_addr_) return NULL; - - Page* cur_page = Page::FromAllocationTop(cur_addr_); +// We have hit the end of the page and should advance to the next block of +// objects. This happens at the end of the page. +bool HeapObjectIterator::AdvanceToNextPage() { + ASSERT(cur_addr_ == cur_end_); + if (page_mode_ == kOnePageOnly) return false; + Page* cur_page; + if (cur_addr_ == NULL) { + cur_page = space_->anchor(); + } else { + cur_page = Page::FromAddress(cur_addr_ - 1); + ASSERT(cur_addr_ == cur_page->ObjectAreaEnd()); + } cur_page = cur_page->next_page(); - ASSERT(cur_page->is_valid()); - + if (cur_page == space_->anchor()) return false; cur_addr_ = cur_page->ObjectAreaStart(); - cur_limit_ = (cur_page == end_page_) ? end_addr_ : cur_page->AllocationTop(); - - if (cur_addr_ == end_addr_) return NULL; - ASSERT(cur_addr_ < cur_limit_); -#ifdef DEBUG - Verify(); -#endif - return FromCurrentPage(); + cur_end_ = cur_page->ObjectAreaEnd(); + ASSERT(cur_page->WasSweptPrecisely()); + return true; } #ifdef DEBUG void HeapObjectIterator::Verify() { - Page* p = Page::FromAllocationTop(cur_addr_); - ASSERT(p == Page::FromAllocationTop(cur_limit_)); - ASSERT(p->Offset(cur_addr_) <= p->Offset(cur_limit_)); + // TODO(gc): We should do something here. } #endif // ----------------------------------------------------------------------------- -// PageIterator - -PageIterator::PageIterator(PagedSpace* space, Mode mode) : space_(space) { - prev_page_ = NULL; - switch (mode) { - case PAGES_IN_USE: - stop_page_ = space->AllocationTopPage(); - break; - case PAGES_USED_BY_MC: - stop_page_ = space->MCRelocationTopPage(); - break; - case ALL_PAGES: -#ifdef DEBUG - // Verify that the cached last page in the space is actually the - // last page. - for (Page* p = space->first_page_; p->is_valid(); p = p->next_page()) { - if (!p->next_page()->is_valid()) { - ASSERT(space->last_page_ == p); - } - } -#endif - stop_page_ = space->last_page_; - break; - } -} - - -// ----------------------------------------------------------------------------- // CodeRange @@ -171,7 +157,12 @@ bool CodeRange::Setup(const size_t requested) { // We are sure that we have mapped a block of requested addresses. ASSERT(code_range_->size() == requested); LOG(isolate_, NewEvent("CodeRange", code_range_->address(), requested)); - allocation_list_.Add(FreeBlock(code_range_->address(), code_range_->size())); + Address base = reinterpret_cast<Address>(code_range_->address()); + Address aligned_base = + RoundUp(reinterpret_cast<Address>(code_range_->address()), + MemoryChunk::kAlignment); + size_t size = code_range_->size() - (aligned_base - base); + allocation_list_.Add(FreeBlock(aligned_base, size)); current_allocation_block_index_ = 0; return true; } @@ -228,7 +219,8 @@ void CodeRange::GetNextAllocationBlock(size_t requested) { -void* CodeRange::AllocateRawMemory(const size_t requested, size_t* allocated) { +Address CodeRange::AllocateRawMemory(const size_t requested, + size_t* allocated) { ASSERT(current_allocation_block_index_ < allocation_list_.length()); if (requested > allocation_list_[current_allocation_block_index_].size) { // Find an allocation block large enough. This function call may @@ -236,13 +228,16 @@ void* CodeRange::AllocateRawMemory(const size_t requested, size_t* allocated) { GetNextAllocationBlock(requested); } // Commit the requested memory at the start of the current allocation block. - *allocated = RoundUp(requested, Page::kPageSize); + size_t aligned_requested = RoundUp(requested, MemoryChunk::kAlignment); FreeBlock current = allocation_list_[current_allocation_block_index_]; - if (*allocated >= current.size - Page::kPageSize) { + if (aligned_requested >= (current.size - Page::kPageSize)) { // Don't leave a small free block, useless for a large object or chunk. *allocated = current.size; + } else { + *allocated = aligned_requested; } ASSERT(*allocated <= current.size); + ASSERT(IsAddressAligned(current.start, MemoryChunk::kAlignment)); if (!code_range_->Commit(current.start, *allocated, true)) { *allocated = 0; return NULL; @@ -256,7 +251,8 @@ void* CodeRange::AllocateRawMemory(const size_t requested, size_t* allocated) { } -void CodeRange::FreeRawMemory(void* address, size_t length) { +void CodeRange::FreeRawMemory(Address address, size_t length) { + ASSERT(IsAddressAligned(address, MemoryChunk::kAlignment)); free_list_.Add(FreeBlock(address, length)); code_range_->Uncommit(address, length); } @@ -274,35 +270,12 @@ void CodeRange::TearDown() { // MemoryAllocator // -// 270 is an estimate based on the static default heap size of a pair of 256K -// semispaces and a 64M old generation. -const int kEstimatedNumberOfChunks = 270; - - MemoryAllocator::MemoryAllocator(Isolate* isolate) : isolate_(isolate), capacity_(0), capacity_executable_(0), size_(0), - size_executable_(0), - initial_chunk_(NULL), - chunks_(kEstimatedNumberOfChunks), - free_chunk_ids_(kEstimatedNumberOfChunks), - max_nof_chunks_(0), - top_(0) { -} - - -void MemoryAllocator::Push(int free_chunk_id) { - ASSERT(max_nof_chunks_ > 0); - ASSERT(top_ < max_nof_chunks_); - free_chunk_ids_[top_++] = free_chunk_id; -} - - -int MemoryAllocator::Pop() { - ASSERT(top_ > 0); - return free_chunk_ids_[--top_]; + size_executable_(0) { } @@ -311,269 +284,303 @@ bool MemoryAllocator::Setup(intptr_t capacity, intptr_t capacity_executable) { capacity_executable_ = RoundUp(capacity_executable, Page::kPageSize); ASSERT_GE(capacity_, capacity_executable_); - // Over-estimate the size of chunks_ array. It assumes the expansion of old - // space is always in the unit of a chunk (kChunkSize) except the last - // expansion. - // - // Due to alignment, allocated space might be one page less than required - // number (kPagesPerChunk) of pages for old spaces. - // - // Reserve two chunk ids for semispaces, one for map space, one for old - // space, and one for code space. - max_nof_chunks_ = - static_cast<int>((capacity_ / (kChunkSize - Page::kPageSize))) + 5; - if (max_nof_chunks_ > kMaxNofChunks) return false; - size_ = 0; size_executable_ = 0; - ChunkInfo info; // uninitialized element. - for (int i = max_nof_chunks_ - 1; i >= 0; i--) { - chunks_.Add(info); - free_chunk_ids_.Add(i); - } - top_ = max_nof_chunks_; + return true; } void MemoryAllocator::TearDown() { - for (int i = 0; i < max_nof_chunks_; i++) { - if (chunks_[i].address() != NULL) DeleteChunk(i); - } - chunks_.Clear(); - free_chunk_ids_.Clear(); - - if (initial_chunk_ != NULL) { - LOG(isolate_, DeleteEvent("InitialChunk", initial_chunk_->address())); - delete initial_chunk_; - initial_chunk_ = NULL; - } - - ASSERT(top_ == max_nof_chunks_); // all chunks are free - top_ = 0; + // Check that spaces were torn down before MemoryAllocator. + ASSERT(size_ == 0); + // TODO(gc) this will be true again when we fix FreeMemory. + // ASSERT(size_executable_ == 0); capacity_ = 0; capacity_executable_ = 0; - size_ = 0; - max_nof_chunks_ = 0; } -void* MemoryAllocator::AllocateRawMemory(const size_t requested, - size_t* allocated, - Executability executable) { - if (size_ + static_cast<size_t>(requested) > static_cast<size_t>(capacity_)) { - return NULL; - } +void MemoryAllocator::FreeMemory(VirtualMemory* reservation, + Executability executable) { + // TODO(gc) make code_range part of memory allocator? + ASSERT(reservation->IsReserved()); + size_t size = reservation->size(); + ASSERT(size_ >= size); + size_ -= size; + + isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size)); - void* mem; if (executable == EXECUTABLE) { - // Check executable memory limit. - if (size_executable_ + requested > - static_cast<size_t>(capacity_executable_)) { - LOG(isolate_, - StringEvent("MemoryAllocator::AllocateRawMemory", - "V8 Executable Allocation capacity exceeded")); - return NULL; - } - // Allocate executable memory either from code range or from the - // OS. - if (isolate_->code_range()->exists()) { - mem = isolate_->code_range()->AllocateRawMemory(requested, allocated); - } else { - mem = OS::Allocate(requested, allocated, true); - } - // Update executable memory size. - size_executable_ += static_cast<int>(*allocated); - } else { - mem = OS::Allocate(requested, allocated, false); + ASSERT(size_executable_ >= size); + size_executable_ -= size; } - int alloced = static_cast<int>(*allocated); - size_ += alloced; - -#ifdef DEBUG - ZapBlock(reinterpret_cast<Address>(mem), alloced); -#endif - isolate_->counters()->memory_allocated()->Increment(alloced); - return mem; + // Code which is part of the code-range does not have its own VirtualMemory. + ASSERT(!isolate_->code_range()->contains( + static_cast<Address>(reservation->address()))); + ASSERT(executable == NOT_EXECUTABLE || !isolate_->code_range()->exists()); + reservation->Release(); } -void MemoryAllocator::FreeRawMemory(void* mem, - size_t length, - Executability executable) { -#ifdef DEBUG - // Do not try to zap the guard page. - size_t guard_size = (executable == EXECUTABLE) ? Page::kPageSize : 0; - ZapBlock(reinterpret_cast<Address>(mem) + guard_size, length - guard_size); -#endif - if (isolate_->code_range()->contains(static_cast<Address>(mem))) { - isolate_->code_range()->FreeRawMemory(mem, length); +void MemoryAllocator::FreeMemory(Address base, + size_t size, + Executability executable) { + // TODO(gc) make code_range part of memory allocator? + ASSERT(size_ >= size); + size_ -= size; + + isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size)); + + if (executable == EXECUTABLE) { + ASSERT(size_executable_ >= size); + size_executable_ -= size; + } + if (isolate_->code_range()->contains(static_cast<Address>(base))) { + ASSERT(executable == EXECUTABLE); + isolate_->code_range()->FreeRawMemory(base, size); } else { - OS::Free(mem, length); + ASSERT(executable == NOT_EXECUTABLE || !isolate_->code_range()->exists()); + bool result = VirtualMemory::ReleaseRegion(base, size); + USE(result); + ASSERT(result); } - isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(length)); - size_ -= static_cast<int>(length); - if (executable == EXECUTABLE) size_executable_ -= static_cast<int>(length); +} - ASSERT(size_ >= 0); - ASSERT(size_executable_ >= 0); + +Address MemoryAllocator::ReserveAlignedMemory(size_t size, + size_t alignment, + VirtualMemory* controller) { + VirtualMemory reservation(size, alignment); + + if (!reservation.IsReserved()) return NULL; + size_ += reservation.size(); + Address base = RoundUp(static_cast<Address>(reservation.address()), + alignment); + controller->TakeControl(&reservation); + return base; } -void MemoryAllocator::PerformAllocationCallback(ObjectSpace space, - AllocationAction action, - size_t size) { - for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { - MemoryAllocationCallbackRegistration registration = - memory_allocation_callbacks_[i]; - if ((registration.space & space) == space && - (registration.action & action) == action) - registration.callback(space, action, static_cast<int>(size)); +Address MemoryAllocator::AllocateAlignedMemory(size_t size, + size_t alignment, + Executability executable, + VirtualMemory* controller) { + VirtualMemory reservation; + Address base = ReserveAlignedMemory(size, alignment, &reservation); + if (base == NULL) return NULL; + if (!reservation.Commit(base, + size, + executable == EXECUTABLE)) { + return NULL; } + controller->TakeControl(&reservation); + return base; } -bool MemoryAllocator::MemoryAllocationCallbackRegistered( - MemoryAllocationCallback callback) { - for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { - if (memory_allocation_callbacks_[i].callback == callback) return true; - } - return false; +void Page::InitializeAsAnchor(PagedSpace* owner) { + set_owner(owner); + set_prev_page(this); + set_next_page(this); } -void MemoryAllocator::AddMemoryAllocationCallback( - MemoryAllocationCallback callback, - ObjectSpace space, - AllocationAction action) { - ASSERT(callback != NULL); - MemoryAllocationCallbackRegistration registration(callback, space, action); - ASSERT(!MemoryAllocator::MemoryAllocationCallbackRegistered(callback)); - return memory_allocation_callbacks_.Add(registration); +NewSpacePage* NewSpacePage::Initialize(Heap* heap, + Address start, + SemiSpace* semi_space) { + MemoryChunk* chunk = MemoryChunk::Initialize(heap, + start, + Page::kPageSize, + NOT_EXECUTABLE, + semi_space); + chunk->set_next_chunk(NULL); + chunk->set_prev_chunk(NULL); + chunk->initialize_scan_on_scavenge(true); + bool in_to_space = (semi_space->id() != kFromSpace); + chunk->SetFlag(in_to_space ? MemoryChunk::IN_TO_SPACE + : MemoryChunk::IN_FROM_SPACE); + ASSERT(!chunk->IsFlagSet(in_to_space ? MemoryChunk::IN_FROM_SPACE + : MemoryChunk::IN_TO_SPACE)); + NewSpacePage* page = static_cast<NewSpacePage*>(chunk); + heap->incremental_marking()->SetNewSpacePageFlags(page); + return page; } -void MemoryAllocator::RemoveMemoryAllocationCallback( - MemoryAllocationCallback callback) { - ASSERT(callback != NULL); - for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { - if (memory_allocation_callbacks_[i].callback == callback) { - memory_allocation_callbacks_.Remove(i); - return; - } - } - UNREACHABLE(); +void NewSpacePage::InitializeAsAnchor(SemiSpace* semi_space) { + set_owner(semi_space); + set_next_chunk(this); + set_prev_chunk(this); + // Flags marks this invalid page as not being in new-space. + // All real new-space pages will be in new-space. + SetFlags(0, ~0); } -void* MemoryAllocator::ReserveInitialChunk(const size_t requested) { - ASSERT(initial_chunk_ == NULL); - initial_chunk_ = new VirtualMemory(requested); - CHECK(initial_chunk_ != NULL); - if (!initial_chunk_->IsReserved()) { - delete initial_chunk_; - initial_chunk_ = NULL; - return NULL; - } +MemoryChunk* MemoryChunk::Initialize(Heap* heap, + Address base, + size_t size, + Executability executable, + Space* owner) { + MemoryChunk* chunk = FromAddress(base); - // We are sure that we have mapped a block of requested addresses. - ASSERT(initial_chunk_->size() == requested); - LOG(isolate_, - NewEvent("InitialChunk", initial_chunk_->address(), requested)); - size_ += static_cast<int>(requested); - return initial_chunk_->address(); -} + ASSERT(base == chunk->address()); + + chunk->heap_ = heap; + chunk->size_ = size; + chunk->flags_ = 0; + chunk->set_owner(owner); + chunk->InitializeReservedMemory(); + chunk->slots_buffer_ = NULL; + chunk->skip_list_ = NULL; + chunk->ResetLiveBytes(); + Bitmap::Clear(chunk); + chunk->initialize_scan_on_scavenge(false); + chunk->SetFlag(WAS_SWEPT_PRECISELY); + ASSERT(OFFSET_OF(MemoryChunk, flags_) == kFlagsOffset); + ASSERT(OFFSET_OF(MemoryChunk, live_byte_count_) == kLiveBytesOffset); -static int PagesInChunk(Address start, size_t size) { - // The first page starts on the first page-aligned address from start onward - // and the last page ends on the last page-aligned address before - // start+size. Page::kPageSize is a power of two so we can divide by - // shifting. - return static_cast<int>((RoundDown(start + size, Page::kPageSize) - - RoundUp(start, Page::kPageSize)) >> kPageSizeBits); + if (executable == EXECUTABLE) chunk->SetFlag(IS_EXECUTABLE); + + if (owner == heap->old_data_space()) chunk->SetFlag(CONTAINS_ONLY_DATA); + + return chunk; } -Page* MemoryAllocator::AllocatePages(int requested_pages, - int* allocated_pages, - PagedSpace* owner) { - if (requested_pages <= 0) return Page::FromAddress(NULL); - size_t chunk_size = requested_pages * Page::kPageSize; +void MemoryChunk::InsertAfter(MemoryChunk* other) { + next_chunk_ = other->next_chunk_; + prev_chunk_ = other; + other->next_chunk_->prev_chunk_ = this; + other->next_chunk_ = this; +} - void* chunk = AllocateRawMemory(chunk_size, &chunk_size, owner->executable()); - if (chunk == NULL) return Page::FromAddress(NULL); - LOG(isolate_, NewEvent("PagedChunk", chunk, chunk_size)); - *allocated_pages = PagesInChunk(static_cast<Address>(chunk), chunk_size); +void MemoryChunk::Unlink() { + if (!InNewSpace() && IsFlagSet(SCAN_ON_SCAVENGE)) { + heap_->decrement_scan_on_scavenge_pages(); + ClearFlag(SCAN_ON_SCAVENGE); + } + next_chunk_->prev_chunk_ = prev_chunk_; + prev_chunk_->next_chunk_ = next_chunk_; + prev_chunk_ = NULL; + next_chunk_ = NULL; +} - // We may 'lose' a page due to alignment. - ASSERT(*allocated_pages >= kPagesPerChunk - 1); - size_t guard_size = (owner->executable() == EXECUTABLE) ? Page::kPageSize : 0; +MemoryChunk* MemoryAllocator::AllocateChunk(intptr_t body_size, + Executability executable, + Space* owner) { + size_t chunk_size = MemoryChunk::kObjectStartOffset + body_size; + Heap* heap = isolate_->heap(); + Address base = NULL; + VirtualMemory reservation; + if (executable == EXECUTABLE) { + // Check executable memory limit. + if (size_executable_ + chunk_size > capacity_executable_) { + LOG(isolate_, + StringEvent("MemoryAllocator::AllocateRawMemory", + "V8 Executable Allocation capacity exceeded")); + return NULL; + } - // Check that we got at least one page that we can use. - if (*allocated_pages <= ((guard_size != 0) ? 1 : 0)) { - FreeRawMemory(chunk, - chunk_size, - owner->executable()); - LOG(isolate_, DeleteEvent("PagedChunk", chunk)); - return Page::FromAddress(NULL); + // Allocate executable memory either from code range or from the + // OS. + if (isolate_->code_range()->exists()) { + base = isolate_->code_range()->AllocateRawMemory(chunk_size, &chunk_size); + ASSERT(IsAligned(reinterpret_cast<intptr_t>(base), + MemoryChunk::kAlignment)); + if (base == NULL) return NULL; + size_ += chunk_size; + // Update executable memory size. + size_executable_ += chunk_size; + } else { + base = AllocateAlignedMemory(chunk_size, + MemoryChunk::kAlignment, + executable, + &reservation); + if (base == NULL) return NULL; + // Update executable memory size. + size_executable_ += reservation.size(); + } + } else { + base = AllocateAlignedMemory(chunk_size, + MemoryChunk::kAlignment, + executable, + &reservation); + + if (base == NULL) return NULL; } - if (guard_size != 0) { - OS::Guard(chunk, guard_size); - chunk_size -= guard_size; - chunk = static_cast<Address>(chunk) + guard_size; - --*allocated_pages; +#ifdef DEBUG + ZapBlock(base, chunk_size); +#endif + isolate_->counters()->memory_allocated()-> + Increment(static_cast<int>(chunk_size)); + + LOG(isolate_, NewEvent("MemoryChunk", base, chunk_size)); + if (owner != NULL) { + ObjectSpace space = static_cast<ObjectSpace>(1 << owner->identity()); + PerformAllocationCallback(space, kAllocationActionAllocate, chunk_size); } - int chunk_id = Pop(); - chunks_[chunk_id].init(static_cast<Address>(chunk), chunk_size, owner); + MemoryChunk* result = MemoryChunk::Initialize(heap, + base, + chunk_size, + executable, + owner); + result->set_reserved_memory(&reservation); + return result; +} + - ObjectSpace space = static_cast<ObjectSpace>(1 << owner->identity()); - PerformAllocationCallback(space, kAllocationActionAllocate, chunk_size); - Page* new_pages = InitializePagesInChunk(chunk_id, *allocated_pages, owner); +Page* MemoryAllocator::AllocatePage(PagedSpace* owner, + Executability executable) { + MemoryChunk* chunk = AllocateChunk(Page::kObjectAreaSize, executable, owner); + + if (chunk == NULL) return NULL; - return new_pages; + return Page::Initialize(isolate_->heap(), chunk, executable, owner); } -Page* MemoryAllocator::CommitPages(Address start, size_t size, - PagedSpace* owner, int* num_pages) { - ASSERT(start != NULL); - *num_pages = PagesInChunk(start, size); - ASSERT(*num_pages > 0); - ASSERT(initial_chunk_ != NULL); - ASSERT(InInitialChunk(start)); - ASSERT(InInitialChunk(start + size - 1)); - if (!initial_chunk_->Commit(start, size, owner->executable() == EXECUTABLE)) { - return Page::FromAddress(NULL); +LargePage* MemoryAllocator::AllocateLargePage(intptr_t object_size, + Executability executable, + Space* owner) { + MemoryChunk* chunk = AllocateChunk(object_size, executable, owner); + if (chunk == NULL) return NULL; + return LargePage::Initialize(isolate_->heap(), chunk); +} + + +void MemoryAllocator::Free(MemoryChunk* chunk) { + LOG(isolate_, DeleteEvent("MemoryChunk", chunk)); + if (chunk->owner() != NULL) { + ObjectSpace space = + static_cast<ObjectSpace>(1 << chunk->owner()->identity()); + PerformAllocationCallback(space, kAllocationActionFree, chunk->size()); } -#ifdef DEBUG - ZapBlock(start, size); -#endif - isolate_->counters()->memory_allocated()->Increment(static_cast<int>(size)); - // So long as we correctly overestimated the number of chunks we should not - // run out of chunk ids. - CHECK(!OutOfChunkIds()); - int chunk_id = Pop(); - chunks_[chunk_id].init(start, size, owner); - return InitializePagesInChunk(chunk_id, *num_pages, owner); + delete chunk->slots_buffer(); + delete chunk->skip_list(); + + VirtualMemory* reservation = chunk->reserved_memory(); + if (reservation->IsReserved()) { + FreeMemory(reservation, chunk->executable()); + } else { + FreeMemory(chunk->address(), + chunk->size(), + chunk->executable()); + } } bool MemoryAllocator::CommitBlock(Address start, size_t size, Executability executable) { - ASSERT(start != NULL); - ASSERT(size > 0); - ASSERT(initial_chunk_ != NULL); - ASSERT(InInitialChunk(start)); - ASSERT(InInitialChunk(start + size - 1)); - - if (!initial_chunk_->Commit(start, size, executable)) return false; + if (!VirtualMemory::CommitRegion(start, size, executable)) return false; #ifdef DEBUG ZapBlock(start, size); #endif @@ -583,13 +590,7 @@ bool MemoryAllocator::CommitBlock(Address start, bool MemoryAllocator::UncommitBlock(Address start, size_t size) { - ASSERT(start != NULL); - ASSERT(size > 0); - ASSERT(initial_chunk_ != NULL); - ASSERT(InInitialChunk(start)); - ASSERT(InInitialChunk(start + size - 1)); - - if (!initial_chunk_->Uncommit(start, size)) return false; + if (!VirtualMemory::UncommitRegion(start, size)) return false; isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size)); return true; } @@ -602,130 +603,49 @@ void MemoryAllocator::ZapBlock(Address start, size_t size) { } -Page* MemoryAllocator::InitializePagesInChunk(int chunk_id, int pages_in_chunk, - PagedSpace* owner) { - ASSERT(IsValidChunk(chunk_id)); - ASSERT(pages_in_chunk > 0); - - Address chunk_start = chunks_[chunk_id].address(); - - Address low = RoundUp(chunk_start, Page::kPageSize); - -#ifdef DEBUG - size_t chunk_size = chunks_[chunk_id].size(); - Address high = RoundDown(chunk_start + chunk_size, Page::kPageSize); - ASSERT(pages_in_chunk <= - ((OffsetFrom(high) - OffsetFrom(low)) / Page::kPageSize)); -#endif - - Address page_addr = low; - for (int i = 0; i < pages_in_chunk; i++) { - Page* p = Page::FromAddress(page_addr); - p->heap_ = owner->heap(); - p->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id; - p->InvalidateWatermark(true); - p->SetIsLargeObjectPage(false); - p->SetAllocationWatermark(p->ObjectAreaStart()); - p->SetCachedAllocationWatermark(p->ObjectAreaStart()); - page_addr += Page::kPageSize; +void MemoryAllocator::PerformAllocationCallback(ObjectSpace space, + AllocationAction action, + size_t size) { + for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { + MemoryAllocationCallbackRegistration registration = + memory_allocation_callbacks_[i]; + if ((registration.space & space) == space && + (registration.action & action) == action) + registration.callback(space, action, static_cast<int>(size)); } - - // Set the next page of the last page to 0. - Page* last_page = Page::FromAddress(page_addr - Page::kPageSize); - last_page->opaque_header = OffsetFrom(0) | chunk_id; - - return Page::FromAddress(low); } -Page* MemoryAllocator::FreePages(Page* p) { - if (!p->is_valid()) return p; - - // Find the first page in the same chunk as 'p' - Page* first_page = FindFirstPageInSameChunk(p); - Page* page_to_return = Page::FromAddress(NULL); - - if (p != first_page) { - // Find the last page in the same chunk as 'prev'. - Page* last_page = FindLastPageInSameChunk(p); - first_page = GetNextPage(last_page); // first page in next chunk - - // set the next_page of last_page to NULL - SetNextPage(last_page, Page::FromAddress(NULL)); - page_to_return = p; // return 'p' when exiting - } - - while (first_page->is_valid()) { - int chunk_id = GetChunkId(first_page); - ASSERT(IsValidChunk(chunk_id)); - - // Find the first page of the next chunk before deleting this chunk. - first_page = GetNextPage(FindLastPageInSameChunk(first_page)); - - // Free the current chunk. - DeleteChunk(chunk_id); +bool MemoryAllocator::MemoryAllocationCallbackRegistered( + MemoryAllocationCallback callback) { + for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { + if (memory_allocation_callbacks_[i].callback == callback) return true; } - - return page_to_return; + return false; } -void MemoryAllocator::FreeAllPages(PagedSpace* space) { - for (int i = 0, length = chunks_.length(); i < length; i++) { - if (chunks_[i].owner() == space) { - DeleteChunk(i); - } - } +void MemoryAllocator::AddMemoryAllocationCallback( + MemoryAllocationCallback callback, + ObjectSpace space, + AllocationAction action) { + ASSERT(callback != NULL); + MemoryAllocationCallbackRegistration registration(callback, space, action); + ASSERT(!MemoryAllocator::MemoryAllocationCallbackRegistered(callback)); + return memory_allocation_callbacks_.Add(registration); } -void MemoryAllocator::DeleteChunk(int chunk_id) { - ASSERT(IsValidChunk(chunk_id)); - - ChunkInfo& c = chunks_[chunk_id]; - - // We cannot free a chunk contained in the initial chunk because it was not - // allocated with AllocateRawMemory. Instead we uncommit the virtual - // memory. - if (InInitialChunk(c.address())) { - // TODO(1240712): VirtualMemory::Uncommit has a return value which - // is ignored here. - initial_chunk_->Uncommit(c.address(), c.size()); - Counters* counters = isolate_->counters(); - counters->memory_allocated()->Decrement(static_cast<int>(c.size())); - } else { - LOG(isolate_, DeleteEvent("PagedChunk", c.address())); - ObjectSpace space = static_cast<ObjectSpace>(1 << c.owner_identity()); - size_t size = c.size(); - size_t guard_size = (c.executable() == EXECUTABLE) ? Page::kPageSize : 0; - FreeRawMemory(c.address() - guard_size, size + guard_size, c.executable()); - PerformAllocationCallback(space, kAllocationActionFree, size); +void MemoryAllocator::RemoveMemoryAllocationCallback( + MemoryAllocationCallback callback) { + ASSERT(callback != NULL); + for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { + if (memory_allocation_callbacks_[i].callback == callback) { + memory_allocation_callbacks_.Remove(i); + return; + } } - c.init(NULL, 0, NULL); - Push(chunk_id); -} - - -Page* MemoryAllocator::FindFirstPageInSameChunk(Page* p) { - int chunk_id = GetChunkId(p); - ASSERT(IsValidChunk(chunk_id)); - - Address low = RoundUp(chunks_[chunk_id].address(), Page::kPageSize); - return Page::FromAddress(low); -} - - -Page* MemoryAllocator::FindLastPageInSameChunk(Page* p) { - int chunk_id = GetChunkId(p); - ASSERT(IsValidChunk(chunk_id)); - - Address chunk_start = chunks_[chunk_id].address(); - size_t chunk_size = chunks_[chunk_id].size(); - - Address high = RoundDown(chunk_start + chunk_size, Page::kPageSize); - ASSERT(chunk_start <= p->address() && p->address() < high); - - return Page::FromAddress(high - Page::kPageSize); + UNREACHABLE(); } @@ -739,75 +659,6 @@ void MemoryAllocator::ReportStatistics() { } #endif - -void MemoryAllocator::RelinkPageListInChunkOrder(PagedSpace* space, - Page** first_page, - Page** last_page, - Page** last_page_in_use) { - Page* first = NULL; - Page* last = NULL; - - for (int i = 0, length = chunks_.length(); i < length; i++) { - ChunkInfo& chunk = chunks_[i]; - - if (chunk.owner() == space) { - if (first == NULL) { - Address low = RoundUp(chunk.address(), Page::kPageSize); - first = Page::FromAddress(low); - } - last = RelinkPagesInChunk(i, - chunk.address(), - chunk.size(), - last, - last_page_in_use); - } - } - - if (first_page != NULL) { - *first_page = first; - } - - if (last_page != NULL) { - *last_page = last; - } -} - - -Page* MemoryAllocator::RelinkPagesInChunk(int chunk_id, - Address chunk_start, - size_t chunk_size, - Page* prev, - Page** last_page_in_use) { - Address page_addr = RoundUp(chunk_start, Page::kPageSize); - int pages_in_chunk = PagesInChunk(chunk_start, chunk_size); - - if (prev->is_valid()) { - SetNextPage(prev, Page::FromAddress(page_addr)); - } - - for (int i = 0; i < pages_in_chunk; i++) { - Page* p = Page::FromAddress(page_addr); - p->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id; - page_addr += Page::kPageSize; - - p->InvalidateWatermark(true); - if (p->WasInUseBeforeMC()) { - *last_page_in_use = p; - } - } - - // Set the next page of the last page to 0. - Page* last_page = Page::FromAddress(page_addr - Page::kPageSize); - last_page->opaque_header = OffsetFrom(0) | chunk_id; - - if (last_page->WasInUseBeforeMC()) { - *last_page_in_use = last_page; - } - - return last_page; -} - - // ----------------------------------------------------------------------------- // PagedSpace implementation @@ -815,7 +666,11 @@ PagedSpace::PagedSpace(Heap* heap, intptr_t max_capacity, AllocationSpace id, Executability executable) - : Space(heap, id, executable) { + : Space(heap, id, executable), + free_list_(this), + was_swept_conservatively_(false), + first_unswept_page_(Page::FromAddress(NULL)), + last_unswept_page_(Page::FromAddress(NULL)) { max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize) * Page::kObjectAreaSize; accounting_stats_.Clear(); @@ -823,215 +678,73 @@ PagedSpace::PagedSpace(Heap* heap, allocation_info_.top = NULL; allocation_info_.limit = NULL; - mc_forwarding_info_.top = NULL; - mc_forwarding_info_.limit = NULL; + anchor_.InitializeAsAnchor(this); } -bool PagedSpace::Setup(Address start, size_t size) { - if (HasBeenSetup()) return false; - - int num_pages = 0; - // Try to use the virtual memory range passed to us. If it is too small to - // contain at least one page, ignore it and allocate instead. - int pages_in_chunk = PagesInChunk(start, size); - if (pages_in_chunk > 0) { - first_page_ = Isolate::Current()->memory_allocator()->CommitPages( - RoundUp(start, Page::kPageSize), - Page::kPageSize * pages_in_chunk, - this, &num_pages); - } else { - int requested_pages = - Min(MemoryAllocator::kPagesPerChunk, - static_cast<int>(max_capacity_ / Page::kObjectAreaSize)); - first_page_ = - Isolate::Current()->memory_allocator()->AllocatePages( - requested_pages, &num_pages, this); - if (!first_page_->is_valid()) return false; - } - - // We are sure that the first page is valid and that we have at least one - // page. - ASSERT(first_page_->is_valid()); - ASSERT(num_pages > 0); - accounting_stats_.ExpandSpace(num_pages * Page::kObjectAreaSize); - ASSERT(Capacity() <= max_capacity_); - - // Sequentially clear region marks in the newly allocated - // pages and cache the current last page in the space. - for (Page* p = first_page_; p->is_valid(); p = p->next_page()) { - p->SetRegionMarks(Page::kAllRegionsCleanMarks); - last_page_ = p; - } - - // Use first_page_ for allocation. - SetAllocationInfo(&allocation_info_, first_page_); - - page_list_is_chunk_ordered_ = true; - +bool PagedSpace::Setup() { return true; } bool PagedSpace::HasBeenSetup() { - return (Capacity() > 0); + return true; } void PagedSpace::TearDown() { - Isolate::Current()->memory_allocator()->FreeAllPages(this); - first_page_ = NULL; - accounting_stats_.Clear(); -} - - -void PagedSpace::MarkAllPagesClean() { - PageIterator it(this, PageIterator::ALL_PAGES); - while (it.has_next()) { - it.next()->SetRegionMarks(Page::kAllRegionsCleanMarks); + PageIterator iterator(this); + while (iterator.has_next()) { + heap()->isolate()->memory_allocator()->Free(iterator.next()); } + anchor_.set_next_page(&anchor_); + anchor_.set_prev_page(&anchor_); + accounting_stats_.Clear(); } MaybeObject* PagedSpace::FindObject(Address addr) { - // Note: this function can only be called before or after mark-compact GC - // because it accesses map pointers. + // Note: this function can only be called on precisely swept spaces. ASSERT(!heap()->mark_compact_collector()->in_use()); if (!Contains(addr)) return Failure::Exception(); Page* p = Page::FromAddress(addr); - ASSERT(IsUsed(p)); - Address cur = p->ObjectAreaStart(); - Address end = p->AllocationTop(); - while (cur < end) { - HeapObject* obj = HeapObject::FromAddress(cur); + HeapObjectIterator it(p, NULL); + for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) { + Address cur = obj->address(); Address next = cur + obj->Size(); if ((cur <= addr) && (addr < next)) return obj; - cur = next; } UNREACHABLE(); return Failure::Exception(); } +bool PagedSpace::CanExpand() { + ASSERT(max_capacity_ % Page::kObjectAreaSize == 0); + ASSERT(Capacity() % Page::kObjectAreaSize == 0); -bool PagedSpace::IsUsed(Page* page) { - PageIterator it(this, PageIterator::PAGES_IN_USE); - while (it.has_next()) { - if (page == it.next()) return true; - } - return false; -} - - -void PagedSpace::SetAllocationInfo(AllocationInfo* alloc_info, Page* p) { - alloc_info->top = p->ObjectAreaStart(); - alloc_info->limit = p->ObjectAreaEnd(); - ASSERT(alloc_info->VerifyPagedAllocation()); -} - - -void PagedSpace::MCResetRelocationInfo() { - // Set page indexes. - int i = 0; - PageIterator it(this, PageIterator::ALL_PAGES); - while (it.has_next()) { - Page* p = it.next(); - p->mc_page_index = i++; - } - - // Set mc_forwarding_info_ to the first page in the space. - SetAllocationInfo(&mc_forwarding_info_, first_page_); - // All the bytes in the space are 'available'. We will rediscover - // allocated and wasted bytes during GC. - accounting_stats_.Reset(); -} - - -int PagedSpace::MCSpaceOffsetForAddress(Address addr) { -#ifdef DEBUG - // The Contains function considers the address at the beginning of a - // page in the page, MCSpaceOffsetForAddress considers it is in the - // previous page. - if (Page::IsAlignedToPageSize(addr)) { - ASSERT(Contains(addr - kPointerSize)); - } else { - ASSERT(Contains(addr)); - } -#endif - - // If addr is at the end of a page, it belongs to previous page - Page* p = Page::IsAlignedToPageSize(addr) - ? Page::FromAllocationTop(addr) - : Page::FromAddress(addr); - int index = p->mc_page_index; - return (index * Page::kPageSize) + p->Offset(addr); -} + if (Capacity() == max_capacity_) return false; + ASSERT(Capacity() < max_capacity_); -// Slow case for reallocating and promoting objects during a compacting -// collection. This function is not space-specific. -HeapObject* PagedSpace::SlowMCAllocateRaw(int size_in_bytes) { - Page* current_page = TopPageOf(mc_forwarding_info_); - if (!current_page->next_page()->is_valid()) { - if (!Expand(current_page)) { - return NULL; - } - } + // Are we going to exceed capacity for this space? + if ((Capacity() + Page::kPageSize) > max_capacity_) return false; - // There are surely more pages in the space now. - ASSERT(current_page->next_page()->is_valid()); - // We do not add the top of page block for current page to the space's - // free list---the block may contain live objects so we cannot write - // bookkeeping information to it. Instead, we will recover top of page - // blocks when we move objects to their new locations. - // - // We do however write the allocation pointer to the page. The encoding - // of forwarding addresses is as an offset in terms of live bytes, so we - // need quick access to the allocation top of each page to decode - // forwarding addresses. - current_page->SetAllocationWatermark(mc_forwarding_info_.top); - current_page->next_page()->InvalidateWatermark(true); - SetAllocationInfo(&mc_forwarding_info_, current_page->next_page()); - return AllocateLinearly(&mc_forwarding_info_, size_in_bytes); + return true; } +bool PagedSpace::Expand() { + if (!CanExpand()) return false; -bool PagedSpace::Expand(Page* last_page) { - ASSERT(max_capacity_ % Page::kObjectAreaSize == 0); - ASSERT(Capacity() % Page::kObjectAreaSize == 0); - - if (Capacity() == max_capacity_) return false; + Page* p = heap()->isolate()->memory_allocator()-> + AllocatePage(this, executable()); + if (p == NULL) return false; - ASSERT(Capacity() < max_capacity_); - // Last page must be valid and its next page is invalid. - ASSERT(last_page->is_valid() && !last_page->next_page()->is_valid()); - - int available_pages = - static_cast<int>((max_capacity_ - Capacity()) / Page::kObjectAreaSize); - // We don't want to have to handle small chunks near the end so if there are - // not kPagesPerChunk pages available without exceeding the max capacity then - // act as if memory has run out. - if (available_pages < MemoryAllocator::kPagesPerChunk) return false; - - int desired_pages = Min(available_pages, MemoryAllocator::kPagesPerChunk); - Page* p = heap()->isolate()->memory_allocator()->AllocatePages( - desired_pages, &desired_pages, this); - if (!p->is_valid()) return false; - - accounting_stats_.ExpandSpace(desired_pages * Page::kObjectAreaSize); ASSERT(Capacity() <= max_capacity_); - heap()->isolate()->memory_allocator()->SetNextPage(last_page, p); - - // Sequentially clear region marks of new pages and and cache the - // new last page in the space. - while (p->is_valid()) { - p->SetRegionMarks(Page::kAllRegionsCleanMarks); - last_page_ = p; - p = p->next_page(); - } + p->InsertAfter(anchor_.prev_page()); return true; } @@ -1039,8 +752,10 @@ bool PagedSpace::Expand(Page* last_page) { #ifdef DEBUG int PagedSpace::CountTotalPages() { + PageIterator it(this); int count = 0; - for (Page* p = first_page_; p->is_valid(); p = p->next_page()) { + while (it.has_next()) { + it.next(); count++; } return count; @@ -1048,63 +763,30 @@ int PagedSpace::CountTotalPages() { #endif -void PagedSpace::Shrink() { - if (!page_list_is_chunk_ordered_) { - // We can't shrink space if pages is not chunk-ordered - // (see comment for class MemoryAllocator for definition). - return; - } - - // Release half of free pages. - Page* top_page = AllocationTopPage(); - ASSERT(top_page->is_valid()); - - // Count the number of pages we would like to free. - int pages_to_free = 0; - for (Page* p = top_page->next_page(); p->is_valid(); p = p->next_page()) { - pages_to_free++; - } - - // Free pages after top_page. - Page* p = heap()->isolate()->memory_allocator()-> - FreePages(top_page->next_page()); - heap()->isolate()->memory_allocator()->SetNextPage(top_page, p); - - // Find out how many pages we failed to free and update last_page_. - // Please note pages can only be freed in whole chunks. - last_page_ = top_page; - for (Page* p = top_page->next_page(); p->is_valid(); p = p->next_page()) { - pages_to_free--; - last_page_ = p; +void PagedSpace::ReleasePage(Page* page) { + ASSERT(page->LiveBytes() == 0); + page->Unlink(); + if (page->IsFlagSet(MemoryChunk::CONTAINS_ONLY_DATA)) { + heap()->isolate()->memory_allocator()->Free(page); + } else { + heap()->QueueMemoryChunkForFree(page); } - accounting_stats_.ShrinkSpace(pages_to_free * Page::kObjectAreaSize); - ASSERT(Capacity() == CountTotalPages() * Page::kObjectAreaSize); + ASSERT(Capacity() > 0); + ASSERT(Capacity() % Page::kObjectAreaSize == 0); + accounting_stats_.ShrinkSpace(Page::kObjectAreaSize); } -bool PagedSpace::EnsureCapacity(int capacity) { - if (Capacity() >= capacity) return true; - - // Start from the allocation top and loop to the last page in the space. - Page* last_page = AllocationTopPage(); - Page* next_page = last_page->next_page(); - while (next_page->is_valid()) { - last_page = heap()->isolate()->memory_allocator()-> - FindLastPageInSameChunk(next_page); - next_page = last_page->next_page(); +void PagedSpace::ReleaseAllUnusedPages() { + PageIterator it(this); + while (it.has_next()) { + Page* page = it.next(); + if (page->LiveBytes() == 0) { + ReleasePage(page); + } } - - // Expand the space until it has the required capacity or expansion fails. - do { - if (!Expand(last_page)) return false; - ASSERT(last_page->next_page()->is_valid()); - last_page = - heap()->isolate()->memory_allocator()->FindLastPageInSameChunk( - last_page->next_page()); - } while (Capacity() < capacity); - - return true; + heap()->FreeQueuedChunks(); } @@ -1114,61 +796,52 @@ void PagedSpace::Print() { } #ifdef DEBUG -// We do not assume that the PageIterator works, because it depends on the -// invariants we are checking during verification. void PagedSpace::Verify(ObjectVisitor* visitor) { - // The allocation pointer should be valid, and it should be in a page in the - // space. - ASSERT(allocation_info_.VerifyPagedAllocation()); - Page* top_page = Page::FromAllocationTop(allocation_info_.top); - ASSERT(heap()->isolate()->memory_allocator()->IsPageInSpace(top_page, this)); - - // Loop over all the pages. - bool above_allocation_top = false; - Page* current_page = first_page_; - while (current_page->is_valid()) { - if (above_allocation_top) { - // We don't care what's above the allocation top. - } else { - Address top = current_page->AllocationTop(); - if (current_page == top_page) { - ASSERT(top == allocation_info_.top); - // The next page will be above the allocation top. - above_allocation_top = true; - } - - // It should be packed with objects from the bottom to the top. - Address current = current_page->ObjectAreaStart(); - while (current < top) { - HeapObject* object = HeapObject::FromAddress(current); - - // The first word should be a map, and we expect all map pointers to - // be in map space. - Map* map = object->map(); - ASSERT(map->IsMap()); - ASSERT(heap()->map_space()->Contains(map)); - - // Perform space-specific object verification. - VerifyObject(object); - - // The object itself should look OK. - object->Verify(); - - // All the interior pointers should be contained in the heap and - // have page regions covering intergenerational references should be - // marked dirty. - int size = object->Size(); - object->IterateBody(map->instance_type(), size, visitor); - - current += size; + // We can only iterate over the pages if they were swept precisely. + if (was_swept_conservatively_) return; + + bool allocation_pointer_found_in_space = + (allocation_info_.top == allocation_info_.limit); + PageIterator page_iterator(this); + while (page_iterator.has_next()) { + Page* page = page_iterator.next(); + ASSERT(page->owner() == this); + if (page == Page::FromAllocationTop(allocation_info_.top)) { + allocation_pointer_found_in_space = true; + } + ASSERT(page->WasSweptPrecisely()); + HeapObjectIterator it(page, NULL); + Address end_of_previous_object = page->ObjectAreaStart(); + Address top = page->ObjectAreaEnd(); + int black_size = 0; + for (HeapObject* object = it.Next(); object != NULL; object = it.Next()) { + ASSERT(end_of_previous_object <= object->address()); + + // The first word should be a map, and we expect all map pointers to + // be in map space. + Map* map = object->map(); + ASSERT(map->IsMap()); + ASSERT(heap()->map_space()->Contains(map)); + + // Perform space-specific object verification. + VerifyObject(object); + + // The object itself should look OK. + object->Verify(); + + // All the interior pointers should be contained in the heap. + int size = object->Size(); + object->IterateBody(map->instance_type(), size, visitor); + if (Marking::IsBlack(Marking::MarkBitFrom(object))) { + black_size += size; } - // The allocation pointer should not be in the middle of an object. - ASSERT(current == top); + ASSERT(object->address() + size <= top); + end_of_previous_object = object->address() + size; } - - current_page = current_page->next_page(); + ASSERT_LE(black_size, page->LiveBytes()); } + ASSERT(allocation_pointer_found_in_space); } #endif @@ -1177,13 +850,23 @@ void PagedSpace::Verify(ObjectVisitor* visitor) { // NewSpace implementation -bool NewSpace::Setup(Address start, int size) { +bool NewSpace::Setup(int reserved_semispace_capacity, + int maximum_semispace_capacity) { // Setup new space based on the preallocated memory block defined by // start and size. The provided space is divided into two semi-spaces. // To support fast containment testing in the new space, the size of // this chunk must be a power of two and it must be aligned to its size. int initial_semispace_capacity = heap()->InitialSemiSpaceSize(); - int maximum_semispace_capacity = heap()->MaxSemiSpaceSize(); + + size_t size = 2 * reserved_semispace_capacity; + Address base = + heap()->isolate()->memory_allocator()->ReserveAlignedMemory( + size, size, &reservation_); + if (base == NULL) return false; + + chunk_base_ = base; + chunk_size_ = static_cast<uintptr_t>(size); + LOG(heap()->isolate(), NewEvent("InitialChunk", chunk_base_, chunk_size_)); ASSERT(initial_semispace_capacity <= maximum_semispace_capacity); ASSERT(IsPowerOf2(maximum_semispace_capacity)); @@ -1197,31 +880,29 @@ bool NewSpace::Setup(Address start, int size) { INSTANCE_TYPE_LIST(SET_NAME) #undef SET_NAME - ASSERT(size == 2 * heap()->ReservedSemiSpaceSize()); - ASSERT(IsAddressAligned(start, size, 0)); + ASSERT(reserved_semispace_capacity == heap()->ReservedSemiSpaceSize()); + ASSERT(static_cast<intptr_t>(chunk_size_) >= + 2 * heap()->ReservedSemiSpaceSize()); + ASSERT(IsAddressAligned(chunk_base_, 2 * reserved_semispace_capacity, 0)); - if (!to_space_.Setup(start, + if (!to_space_.Setup(chunk_base_, initial_semispace_capacity, maximum_semispace_capacity)) { return false; } - if (!from_space_.Setup(start + maximum_semispace_capacity, + if (!from_space_.Setup(chunk_base_ + reserved_semispace_capacity, initial_semispace_capacity, maximum_semispace_capacity)) { return false; } - start_ = start; - address_mask_ = ~(size - 1); + start_ = chunk_base_; + address_mask_ = ~(2 * reserved_semispace_capacity - 1); object_mask_ = address_mask_ | kHeapObjectTagMask; - object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag; + object_expected_ = reinterpret_cast<uintptr_t>(start_) | kHeapObjectTag; - allocation_info_.top = to_space_.low(); - allocation_info_.limit = to_space_.high(); - mc_forwarding_info_.top = NULL; - mc_forwarding_info_.limit = NULL; + ResetAllocationInfo(); - ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); return true; } @@ -1239,28 +920,34 @@ void NewSpace::TearDown() { start_ = NULL; allocation_info_.top = NULL; allocation_info_.limit = NULL; - mc_forwarding_info_.top = NULL; - mc_forwarding_info_.limit = NULL; to_space_.TearDown(); from_space_.TearDown(); + + LOG(heap()->isolate(), DeleteEvent("InitialChunk", chunk_base_)); + + ASSERT(reservation_.IsReserved()); + heap()->isolate()->memory_allocator()->FreeMemory(&reservation_, + NOT_EXECUTABLE); + chunk_base_ = NULL; + chunk_size_ = 0; } void NewSpace::Flip() { - SemiSpace tmp = from_space_; - from_space_ = to_space_; - to_space_ = tmp; + SemiSpace::Swap(&from_space_, &to_space_); } void NewSpace::Grow() { + // Double the semispace size but only up to maximum capacity. ASSERT(Capacity() < MaximumCapacity()); - if (to_space_.Grow()) { - // Only grow from space if we managed to grow to space. - if (!from_space_.Grow()) { - // If we managed to grow to space but couldn't grow from space, - // attempt to shrink to space. + int new_capacity = Min(MaximumCapacity(), 2 * static_cast<int>(Capacity())); + if (to_space_.GrowTo(new_capacity)) { + // Only grow from space if we managed to grow to-space. + if (!from_space_.GrowTo(new_capacity)) { + // If we managed to grow to-space but couldn't grow from-space, + // attempt to shrink to-space. if (!to_space_.ShrinkTo(from_space_.Capacity())) { // We are in an inconsistent state because we could not // commit/uncommit memory from new space. @@ -1268,21 +955,20 @@ void NewSpace::Grow() { } } } - allocation_info_.limit = to_space_.high(); ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); } void NewSpace::Shrink() { int new_capacity = Max(InitialCapacity(), 2 * SizeAsInt()); - int rounded_new_capacity = - RoundUp(new_capacity, static_cast<int>(OS::AllocateAlignment())); + int rounded_new_capacity = RoundUp(new_capacity, Page::kPageSize); if (rounded_new_capacity < Capacity() && to_space_.ShrinkTo(rounded_new_capacity)) { - // Only shrink from space if we managed to shrink to space. + // Only shrink from-space if we managed to shrink to-space. + from_space_.Reset(); if (!from_space_.ShrinkTo(rounded_new_capacity)) { - // If we managed to shrink to space but couldn't shrink from - // space, attempt to grow to space again. + // If we managed to shrink to-space but couldn't shrink from + // space, attempt to grow to-space again. if (!to_space_.GrowTo(from_space_.Capacity())) { // We are in an inconsistent state because we could not // commit/uncommit memory from new space. @@ -1290,36 +976,65 @@ void NewSpace::Shrink() { } } } - allocation_info_.limit = to_space_.high(); + allocation_info_.limit = to_space_.page_high(); ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); } -void NewSpace::ResetAllocationInfo() { - allocation_info_.top = to_space_.low(); - allocation_info_.limit = to_space_.high(); +void NewSpace::UpdateAllocationInfo() { + allocation_info_.top = to_space_.page_low(); + allocation_info_.limit = to_space_.page_high(); + + // Lower limit during incremental marking. + if (heap()->incremental_marking()->IsMarking() && + inline_allocation_limit_step() != 0) { + Address new_limit = + allocation_info_.top + inline_allocation_limit_step(); + allocation_info_.limit = Min(new_limit, allocation_info_.limit); + } ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); } -void NewSpace::MCResetRelocationInfo() { - mc_forwarding_info_.top = from_space_.low(); - mc_forwarding_info_.limit = from_space_.high(); - ASSERT_SEMISPACE_ALLOCATION_INFO(mc_forwarding_info_, from_space_); +void NewSpace::ResetAllocationInfo() { + to_space_.Reset(); + UpdateAllocationInfo(); + pages_used_ = 0; + // Clear all mark-bits in the to-space. + NewSpacePageIterator it(&to_space_); + while (it.has_next()) { + Bitmap::Clear(it.next()); + } } -void NewSpace::MCCommitRelocationInfo() { - // Assumes that the spaces have been flipped so that mc_forwarding_info_ is - // valid allocation info for the to space. - allocation_info_.top = mc_forwarding_info_.top; - allocation_info_.limit = to_space_.high(); - ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); +bool NewSpace::AddFreshPage() { + Address top = allocation_info_.top; + if (NewSpacePage::IsAtStart(top)) { + // The current page is already empty. Don't try to make another. + + // We should only get here if someone asks to allocate more + // than what can be stored in a single page. + // TODO(gc): Change the limit on new-space allocation to prevent this + // from happening (all such allocations should go directly to LOSpace). + return false; + } + if (!to_space_.AdvancePage()) { + // Failed to get a new page in to-space. + return false; + } + // Clear remainder of current page. + int remaining_in_page = + static_cast<int>(NewSpacePage::FromLimit(top)->body_limit() - top); + heap()->CreateFillerObjectAt(top, remaining_in_page); + pages_used_++; + UpdateAllocationInfo(); + return true; } #ifdef DEBUG -// We do not use the SemispaceIterator because verification doesn't assume +// We do not use the SemiSpaceIterator because verification doesn't assume // that it works (it depends on the invariants we are checking). void NewSpace::Verify() { // The allocation pointer should be in the space or at the very end. @@ -1327,58 +1042,52 @@ void NewSpace::Verify() { // There should be objects packed in from the low address up to the // allocation pointer. - Address current = to_space_.low(); - while (current < top()) { - HeapObject* object = HeapObject::FromAddress(current); - - // The first word should be a map, and we expect all map pointers to - // be in map space. - Map* map = object->map(); - ASSERT(map->IsMap()); - ASSERT(heap()->map_space()->Contains(map)); + Address current = to_space_.first_page()->body(); + CHECK_EQ(current, to_space_.space_start()); - // The object should not be code or a map. - ASSERT(!object->IsMap()); - ASSERT(!object->IsCode()); + while (current != top()) { + if (!NewSpacePage::IsAtEnd(current)) { + // The allocation pointer should not be in the middle of an object. + CHECK(!NewSpacePage::FromLimit(current)->ContainsLimit(top()) || + current < top()); - // The object itself should look OK. - object->Verify(); + HeapObject* object = HeapObject::FromAddress(current); - // All the interior pointers should be contained in the heap. - VerifyPointersVisitor visitor; - int size = object->Size(); - object->IterateBody(map->instance_type(), size, &visitor); + // The first word should be a map, and we expect all map pointers to + // be in map space. + Map* map = object->map(); + CHECK(map->IsMap()); + CHECK(heap()->map_space()->Contains(map)); - current += size; - } + // The object should not be code or a map. + CHECK(!object->IsMap()); + CHECK(!object->IsCode()); - // The allocation pointer should not be in the middle of an object. - ASSERT(current == top()); -} -#endif + // The object itself should look OK. + object->Verify(); + // All the interior pointers should be contained in the heap. + VerifyPointersVisitor visitor; + int size = object->Size(); + object->IterateBody(map->instance_type(), size, &visitor); -bool SemiSpace::Commit() { - ASSERT(!is_committed()); - if (!heap()->isolate()->memory_allocator()->CommitBlock( - start_, capacity_, executable())) { - return false; + current += size; + } else { + // At end of page, switch to next page. + NewSpacePage* page = NewSpacePage::FromLimit(current)->next_page(); + // Next page should be valid. + CHECK(!page->is_anchor()); + current = page->body(); + } } - committed_ = true; - return true; -} - -bool SemiSpace::Uncommit() { - ASSERT(is_committed()); - if (!heap()->isolate()->memory_allocator()->UncommitBlock( - start_, capacity_)) { - return false; - } - committed_ = false; - return true; + // Check semi-spaces. + ASSERT_EQ(from_space_.id(), kFromSpace); + ASSERT_EQ(to_space_.id(), kToSpace); + from_space_.Verify(); + to_space_.Verify(); } - +#endif // ----------------------------------------------------------------------------- // SemiSpace implementation @@ -1392,11 +1101,11 @@ bool SemiSpace::Setup(Address start, // otherwise. In the mark-compact collector, the memory region of the from // space is used as the marking stack. It requires contiguous memory // addresses. - initial_capacity_ = initial_capacity; + ASSERT(maximum_capacity >= Page::kPageSize); + initial_capacity_ = RoundDown(initial_capacity, Page::kPageSize); capacity_ = initial_capacity; - maximum_capacity_ = maximum_capacity; + maximum_capacity_ = RoundDown(maximum_capacity, Page::kPageSize); committed_ = false; - start_ = start; address_mask_ = ~(maximum_capacity - 1); object_mask_ = address_mask_ | kHeapObjectTagMask; @@ -1413,81 +1122,258 @@ void SemiSpace::TearDown() { } -bool SemiSpace::Grow() { - // Double the semispace size but only up to maximum capacity. - int maximum_extra = maximum_capacity_ - capacity_; - int extra = Min(RoundUp(capacity_, static_cast<int>(OS::AllocateAlignment())), - maximum_extra); - if (!heap()->isolate()->memory_allocator()->CommitBlock( - high(), extra, executable())) { +bool SemiSpace::Commit() { + ASSERT(!is_committed()); + int pages = capacity_ / Page::kPageSize; + Address end = start_ + maximum_capacity_; + Address start = end - pages * Page::kPageSize; + if (!heap()->isolate()->memory_allocator()->CommitBlock(start, + capacity_, + executable())) { return false; } - capacity_ += extra; + + NewSpacePage* page = anchor(); + for (int i = 1; i <= pages; i++) { + NewSpacePage* new_page = + NewSpacePage::Initialize(heap(), end - i * Page::kPageSize, this); + new_page->InsertAfter(page); + page = new_page; + } + + committed_ = true; + Reset(); + return true; +} + + +bool SemiSpace::Uncommit() { + ASSERT(is_committed()); + Address start = start_ + maximum_capacity_ - capacity_; + if (!heap()->isolate()->memory_allocator()->UncommitBlock(start, capacity_)) { + return false; + } + anchor()->set_next_page(anchor()); + anchor()->set_prev_page(anchor()); + + committed_ = false; return true; } bool SemiSpace::GrowTo(int new_capacity) { + ASSERT((new_capacity & Page::kPageAlignmentMask) == 0); ASSERT(new_capacity <= maximum_capacity_); ASSERT(new_capacity > capacity_); + int pages_before = capacity_ / Page::kPageSize; + int pages_after = new_capacity / Page::kPageSize; + + Address end = start_ + maximum_capacity_; + Address start = end - new_capacity; size_t delta = new_capacity - capacity_; + ASSERT(IsAligned(delta, OS::AllocateAlignment())); if (!heap()->isolate()->memory_allocator()->CommitBlock( - high(), delta, executable())) { + start, delta, executable())) { return false; } capacity_ = new_capacity; + NewSpacePage* last_page = anchor()->prev_page(); + ASSERT(last_page != anchor()); + for (int i = pages_before + 1; i <= pages_after; i++) { + Address page_address = end - i * Page::kPageSize; + NewSpacePage* new_page = NewSpacePage::Initialize(heap(), + page_address, + this); + new_page->InsertAfter(last_page); + Bitmap::Clear(new_page); + // Duplicate the flags that was set on the old page. + new_page->SetFlags(last_page->GetFlags(), + NewSpacePage::kCopyOnFlipFlagsMask); + last_page = new_page; + } return true; } bool SemiSpace::ShrinkTo(int new_capacity) { + ASSERT((new_capacity & Page::kPageAlignmentMask) == 0); ASSERT(new_capacity >= initial_capacity_); ASSERT(new_capacity < capacity_); + // Semispaces grow backwards from the end of their allocated capacity, + // so we find the before and after start addresses relative to the + // end of the space. + Address space_end = start_ + maximum_capacity_; + Address old_start = space_end - capacity_; size_t delta = capacity_ - new_capacity; ASSERT(IsAligned(delta, OS::AllocateAlignment())); - if (!heap()->isolate()->memory_allocator()->UncommitBlock( - high() - delta, delta)) { + if (!heap()->isolate()->memory_allocator()->UncommitBlock(old_start, delta)) { return false; } capacity_ = new_capacity; + + int pages_after = capacity_ / Page::kPageSize; + NewSpacePage* new_last_page = + NewSpacePage::FromAddress(space_end - pages_after * Page::kPageSize); + new_last_page->set_next_page(anchor()); + anchor()->set_prev_page(new_last_page); + ASSERT((current_page_ <= first_page()) && (current_page_ >= new_last_page)); + return true; } +void SemiSpace::FlipPages(intptr_t flags, intptr_t mask) { + anchor_.set_owner(this); + // Fixup back-pointers to anchor. Address of anchor changes + // when we swap. + anchor_.prev_page()->set_next_page(&anchor_); + anchor_.next_page()->set_prev_page(&anchor_); + + bool becomes_to_space = (id_ == kFromSpace); + id_ = becomes_to_space ? kToSpace : kFromSpace; + NewSpacePage* page = anchor_.next_page(); + while (page != &anchor_) { + page->set_owner(this); + page->SetFlags(flags, mask); + if (becomes_to_space) { + page->ClearFlag(MemoryChunk::IN_FROM_SPACE); + page->SetFlag(MemoryChunk::IN_TO_SPACE); + page->ClearFlag(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK); + page->ResetLiveBytes(); + } else { + page->SetFlag(MemoryChunk::IN_FROM_SPACE); + page->ClearFlag(MemoryChunk::IN_TO_SPACE); + } + ASSERT(page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE)); + ASSERT(page->IsFlagSet(MemoryChunk::IN_TO_SPACE) || + page->IsFlagSet(MemoryChunk::IN_FROM_SPACE)); + page = page->next_page(); + } +} + + +void SemiSpace::Reset() { + ASSERT(anchor_.next_page() != &anchor_); + current_page_ = anchor_.next_page(); +} + + +void SemiSpace::Swap(SemiSpace* from, SemiSpace* to) { + // We won't be swapping semispaces without data in them. + ASSERT(from->anchor_.next_page() != &from->anchor_); + ASSERT(to->anchor_.next_page() != &to->anchor_); + + // Swap bits. + SemiSpace tmp = *from; + *from = *to; + *to = tmp; + + // Fixup back-pointers to the page list anchor now that its address + // has changed. + // Swap to/from-space bits on pages. + // Copy GC flags from old active space (from-space) to new (to-space). + intptr_t flags = from->current_page()->GetFlags(); + to->FlipPages(flags, NewSpacePage::kCopyOnFlipFlagsMask); + + from->FlipPages(0, 0); +} + + +void SemiSpace::set_age_mark(Address mark) { + ASSERT(NewSpacePage::FromLimit(mark)->semi_space() == this); + age_mark_ = mark; + // Mark all pages up to the one containing mark. + NewSpacePageIterator it(space_start(), mark); + while (it.has_next()) { + it.next()->SetFlag(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK); + } +} + + #ifdef DEBUG void SemiSpace::Print() { } -void SemiSpace::Verify() { } +void SemiSpace::Verify() { + bool is_from_space = (id_ == kFromSpace); + NewSpacePage* page = anchor_.next_page(); + CHECK(anchor_.semi_space() == this); + while (page != &anchor_) { + CHECK(page->semi_space() == this); + CHECK(page->InNewSpace()); + CHECK(page->IsFlagSet(is_from_space ? MemoryChunk::IN_FROM_SPACE + : MemoryChunk::IN_TO_SPACE)); + CHECK(!page->IsFlagSet(is_from_space ? MemoryChunk::IN_TO_SPACE + : MemoryChunk::IN_FROM_SPACE)); + CHECK(page->IsFlagSet(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING)); + if (!is_from_space) { + // The pointers-from-here-are-interesting flag isn't updated dynamically + // on from-space pages, so it might be out of sync with the marking state. + if (page->heap()->incremental_marking()->IsMarking()) { + CHECK(page->IsFlagSet(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING)); + } else { + CHECK(!page->IsFlagSet( + MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING)); + } + // TODO(gc): Check that the live_bytes_count_ field matches the + // black marking on the page (if we make it match in new-space). + } + CHECK(page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE)); + CHECK(page->prev_page()->next_page() == page); + page = page->next_page(); + } +} + + +void SemiSpace::AssertValidRange(Address start, Address end) { + // Addresses belong to same semi-space + NewSpacePage* page = NewSpacePage::FromLimit(start); + NewSpacePage* end_page = NewSpacePage::FromLimit(end); + SemiSpace* space = page->semi_space(); + CHECK_EQ(space, end_page->semi_space()); + // Start address is before end address, either on same page, + // or end address is on a later page in the linked list of + // semi-space pages. + if (page == end_page) { + CHECK(start <= end); + } else { + while (page != end_page) { + page = page->next_page(); + CHECK_NE(page, space->anchor()); + } + } +} #endif // ----------------------------------------------------------------------------- // SemiSpaceIterator implementation. SemiSpaceIterator::SemiSpaceIterator(NewSpace* space) { - Initialize(space, space->bottom(), space->top(), NULL); + Initialize(space->bottom(), space->top(), NULL); } SemiSpaceIterator::SemiSpaceIterator(NewSpace* space, HeapObjectCallback size_func) { - Initialize(space, space->bottom(), space->top(), size_func); + Initialize(space->bottom(), space->top(), size_func); } SemiSpaceIterator::SemiSpaceIterator(NewSpace* space, Address start) { - Initialize(space, start, space->top(), NULL); + Initialize(start, space->top(), NULL); +} + + +SemiSpaceIterator::SemiSpaceIterator(Address from, Address to) { + Initialize(from, to, NULL); } -void SemiSpaceIterator::Initialize(NewSpace* space, Address start, +void SemiSpaceIterator::Initialize(Address start, Address end, HeapObjectCallback size_func) { - ASSERT(space->ToSpaceContains(start)); - ASSERT(space->ToSpaceLow() <= end - && end <= space->ToSpaceHigh()); - space_ = &space->to_space_; + SemiSpace::AssertValidRange(start, end); current_ = start; limit_ = end; size_func_ = size_func; @@ -1623,7 +1509,7 @@ void NewSpace::ClearHistograms() { void NewSpace::CollectStatistics() { ClearHistograms(); SemiSpaceIterator it(this); - for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) + for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) RecordAllocation(obj); } @@ -1699,7 +1585,6 @@ void NewSpace::RecordPromotion(HeapObject* obj) { promoted_histogram_[type].increment_bytes(obj->Size()); } - // ----------------------------------------------------------------------------- // Free lists for old object spaces implementation @@ -1708,17 +1593,17 @@ void FreeListNode::set_size(Heap* heap, int size_in_bytes) { ASSERT(IsAligned(size_in_bytes, kPointerSize)); // We write a map and possibly size information to the block. If the block - // is big enough to be a ByteArray with at least one extra word (the next - // pointer), we set its map to be the byte array map and its size to an + // is big enough to be a FreeSpace with at least one extra word (the next + // pointer), we set its map to be the free space map and its size to an // appropriate array length for the desired size from HeapObject::Size(). // If the block is too small (eg, one or two words), to hold both a size // field and a next pointer, we give it a filler map that gives it the // correct size. - if (size_in_bytes > ByteArray::kHeaderSize) { - set_map(heap->raw_unchecked_byte_array_map()); - // Can't use ByteArray::cast because it fails during deserialization. - ByteArray* this_as_byte_array = reinterpret_cast<ByteArray*>(this); - this_as_byte_array->set_length(ByteArray::LengthFor(size_in_bytes)); + if (size_in_bytes > FreeSpace::kHeaderSize) { + set_map(heap->raw_unchecked_free_space_map()); + // Can't use FreeSpace::cast because it fails during deserialization. + FreeSpace* this_as_free_space = reinterpret_cast<FreeSpace*>(this); + this_as_free_space->set_size(size_in_bytes); } else if (size_in_bytes == kPointerSize) { set_map(heap->raw_unchecked_one_pointer_filler_map()); } else if (size_in_bytes == 2 * kPointerSize) { @@ -1727,318 +1612,300 @@ void FreeListNode::set_size(Heap* heap, int size_in_bytes) { UNREACHABLE(); } // We would like to ASSERT(Size() == size_in_bytes) but this would fail during - // deserialization because the byte array map is not done yet. + // deserialization because the free space map is not done yet. } -Address FreeListNode::next(Heap* heap) { +FreeListNode* FreeListNode::next() { ASSERT(IsFreeListNode(this)); - if (map() == heap->raw_unchecked_byte_array_map()) { - ASSERT(Size() >= kNextOffset + kPointerSize); - return Memory::Address_at(address() + kNextOffset); + if (map() == HEAP->raw_unchecked_free_space_map()) { + ASSERT(map() == NULL || Size() >= kNextOffset + kPointerSize); + return reinterpret_cast<FreeListNode*>( + Memory::Address_at(address() + kNextOffset)); } else { - return Memory::Address_at(address() + kPointerSize); + return reinterpret_cast<FreeListNode*>( + Memory::Address_at(address() + kPointerSize)); } } -void FreeListNode::set_next(Heap* heap, Address next) { +FreeListNode** FreeListNode::next_address() { ASSERT(IsFreeListNode(this)); - if (map() == heap->raw_unchecked_byte_array_map()) { + if (map() == HEAP->raw_unchecked_free_space_map()) { ASSERT(Size() >= kNextOffset + kPointerSize); - Memory::Address_at(address() + kNextOffset) = next; + return reinterpret_cast<FreeListNode**>(address() + kNextOffset); } else { - Memory::Address_at(address() + kPointerSize) = next; + return reinterpret_cast<FreeListNode**>(address() + kPointerSize); } } -OldSpaceFreeList::OldSpaceFreeList(Heap* heap, AllocationSpace owner) - : heap_(heap), - owner_(owner) { - Reset(); +void FreeListNode::set_next(FreeListNode* next) { + ASSERT(IsFreeListNode(this)); + // While we are booting the VM the free space map will actually be null. So + // we have to make sure that we don't try to use it for anything at that + // stage. + if (map() == HEAP->raw_unchecked_free_space_map()) { + ASSERT(map() == NULL || Size() >= kNextOffset + kPointerSize); + Memory::Address_at(address() + kNextOffset) = + reinterpret_cast<Address>(next); + } else { + Memory::Address_at(address() + kPointerSize) = + reinterpret_cast<Address>(next); + } } -void OldSpaceFreeList::Reset() { - available_ = 0; - for (int i = 0; i < kFreeListsLength; i++) { - free_[i].head_node_ = NULL; - } - needs_rebuild_ = false; - finger_ = kHead; - free_[kHead].next_size_ = kEnd; +FreeList::FreeList(PagedSpace* owner) + : owner_(owner), heap_(owner->heap()) { + Reset(); } -void OldSpaceFreeList::RebuildSizeList() { - ASSERT(needs_rebuild_); - int cur = kHead; - for (int i = cur + 1; i < kFreeListsLength; i++) { - if (free_[i].head_node_ != NULL) { - free_[cur].next_size_ = i; - cur = i; - } - } - free_[cur].next_size_ = kEnd; - needs_rebuild_ = false; +void FreeList::Reset() { + available_ = 0; + small_list_ = NULL; + medium_list_ = NULL; + large_list_ = NULL; + huge_list_ = NULL; } -int OldSpaceFreeList::Free(Address start, int size_in_bytes) { -#ifdef DEBUG - Isolate::Current()->memory_allocator()->ZapBlock(start, size_in_bytes); -#endif +int FreeList::Free(Address start, int size_in_bytes) { + if (size_in_bytes == 0) return 0; FreeListNode* node = FreeListNode::FromAddress(start); node->set_size(heap_, size_in_bytes); - // We don't use the freelists in compacting mode. This makes it more like a - // GC that only has mark-sweep-compact and doesn't have a mark-sweep - // collector. - if (FLAG_always_compact) { - return size_in_bytes; - } - - // Early return to drop too-small blocks on the floor (one or two word - // blocks cannot hold a map pointer, a size field, and a pointer to the - // next block in the free list). - if (size_in_bytes < kMinBlockSize) { - return size_in_bytes; + // Early return to drop too-small blocks on the floor. + if (size_in_bytes < kSmallListMin) return size_in_bytes; + + // Insert other blocks at the head of a free list of the appropriate + // magnitude. + if (size_in_bytes <= kSmallListMax) { + node->set_next(small_list_); + small_list_ = node; + } else if (size_in_bytes <= kMediumListMax) { + node->set_next(medium_list_); + medium_list_ = node; + } else if (size_in_bytes <= kLargeListMax) { + node->set_next(large_list_); + large_list_ = node; + } else { + node->set_next(huge_list_); + huge_list_ = node; } - - // Insert other blocks at the head of an exact free list. - int index = size_in_bytes >> kPointerSizeLog2; - node->set_next(heap_, free_[index].head_node_); - free_[index].head_node_ = node->address(); available_ += size_in_bytes; - needs_rebuild_ = true; + ASSERT(IsVeryLong() || available_ == SumFreeLists()); return 0; } -MaybeObject* OldSpaceFreeList::Allocate(int size_in_bytes, int* wasted_bytes) { - ASSERT(0 < size_in_bytes); - ASSERT(size_in_bytes <= kMaxBlockSize); - ASSERT(IsAligned(size_in_bytes, kPointerSize)); +FreeListNode* FreeList::PickNodeFromList(FreeListNode** list, int* node_size) { + FreeListNode* node = *list; - if (needs_rebuild_) RebuildSizeList(); - int index = size_in_bytes >> kPointerSizeLog2; - // Check for a perfect fit. - if (free_[index].head_node_ != NULL) { - FreeListNode* node = FreeListNode::FromAddress(free_[index].head_node_); - // If this was the last block of its size, remove the size. - if ((free_[index].head_node_ = node->next(heap_)) == NULL) - RemoveSize(index); - available_ -= size_in_bytes; - *wasted_bytes = 0; - ASSERT(!FLAG_always_compact); // We only use the freelists with mark-sweep. - return node; - } - // Search the size list for the best fit. - int prev = finger_ < index ? finger_ : kHead; - int cur = FindSize(index, &prev); - ASSERT(index < cur); - if (cur == kEnd) { - // No large enough size in list. - *wasted_bytes = 0; - return Failure::RetryAfterGC(owner_); - } - ASSERT(!FLAG_always_compact); // We only use the freelists with mark-sweep. - int rem = cur - index; - int rem_bytes = rem << kPointerSizeLog2; - FreeListNode* cur_node = FreeListNode::FromAddress(free_[cur].head_node_); - ASSERT(cur_node->Size() == (cur << kPointerSizeLog2)); - FreeListNode* rem_node = FreeListNode::FromAddress(free_[cur].head_node_ + - size_in_bytes); - // Distinguish the cases prev < rem < cur and rem <= prev < cur - // to avoid many redundant tests and calls to Insert/RemoveSize. - if (prev < rem) { - // Simple case: insert rem between prev and cur. - finger_ = prev; - free_[prev].next_size_ = rem; - // If this was the last block of size cur, remove the size. - if ((free_[cur].head_node_ = cur_node->next(heap_)) == NULL) { - free_[rem].next_size_ = free_[cur].next_size_; - } else { - free_[rem].next_size_ = cur; - } - // Add the remainder block. - rem_node->set_size(heap_, rem_bytes); - rem_node->set_next(heap_, free_[rem].head_node_); - free_[rem].head_node_ = rem_node->address(); + if (node == NULL) return NULL; + + while (node != NULL && + Page::FromAddress(node->address())->IsEvacuationCandidate()) { + available_ -= node->Size(); + node = node->next(); + } + + if (node != NULL) { + *node_size = node->Size(); + *list = node->next(); } else { - // If this was the last block of size cur, remove the size. - if ((free_[cur].head_node_ = cur_node->next(heap_)) == NULL) { - finger_ = prev; - free_[prev].next_size_ = free_[cur].next_size_; - } - if (rem_bytes < kMinBlockSize) { - // Too-small remainder is wasted. - rem_node->set_size(heap_, rem_bytes); - available_ -= size_in_bytes + rem_bytes; - *wasted_bytes = rem_bytes; - return cur_node; - } - // Add the remainder block and, if needed, insert its size. - rem_node->set_size(heap_, rem_bytes); - rem_node->set_next(heap_, free_[rem].head_node_); - free_[rem].head_node_ = rem_node->address(); - if (rem_node->next(heap_) == NULL) InsertSize(rem); + *list = NULL; } - available_ -= size_in_bytes; - *wasted_bytes = 0; - return cur_node; + + return node; } -void OldSpaceFreeList::MarkNodes() { - for (int i = 0; i < kFreeListsLength; i++) { - Address cur_addr = free_[i].head_node_; - while (cur_addr != NULL) { - FreeListNode* cur_node = FreeListNode::FromAddress(cur_addr); - cur_addr = cur_node->next(heap_); - cur_node->SetMark(); - } - } -} +FreeListNode* FreeList::FindNodeFor(int size_in_bytes, int* node_size) { + FreeListNode* node = NULL; + if (size_in_bytes <= kSmallAllocationMax) { + node = PickNodeFromList(&small_list_, node_size); + if (node != NULL) return node; + } -#ifdef DEBUG -bool OldSpaceFreeList::Contains(FreeListNode* node) { - for (int i = 0; i < kFreeListsLength; i++) { - Address cur_addr = free_[i].head_node_; - while (cur_addr != NULL) { - FreeListNode* cur_node = FreeListNode::FromAddress(cur_addr); - if (cur_node == node) return true; - cur_addr = cur_node->next(heap_); - } + if (size_in_bytes <= kMediumAllocationMax) { + node = PickNodeFromList(&medium_list_, node_size); + if (node != NULL) return node; } - return false; -} -#endif + if (size_in_bytes <= kLargeAllocationMax) { + node = PickNodeFromList(&large_list_, node_size); + if (node != NULL) return node; + } -FixedSizeFreeList::FixedSizeFreeList(Heap* heap, - AllocationSpace owner, - int object_size) - : heap_(heap), owner_(owner), object_size_(object_size) { - Reset(); -} + for (FreeListNode** cur = &huge_list_; + *cur != NULL; + cur = (*cur)->next_address()) { + FreeListNode* cur_node = *cur; + while (cur_node != NULL && + Page::FromAddress(cur_node->address())->IsEvacuationCandidate()) { + available_ -= reinterpret_cast<FreeSpace*>(cur_node)->Size(); + cur_node = cur_node->next(); + } + *cur = cur_node; + if (cur_node == NULL) break; + + ASSERT((*cur)->map() == HEAP->raw_unchecked_free_space_map()); + FreeSpace* cur_as_free_space = reinterpret_cast<FreeSpace*>(*cur); + int size = cur_as_free_space->Size(); + if (size >= size_in_bytes) { + // Large enough node found. Unlink it from the list. + node = *cur; + *node_size = size; + *cur = node->next(); + break; + } + } -void FixedSizeFreeList::Reset() { - available_ = 0; - head_ = tail_ = NULL; + return node; } -void FixedSizeFreeList::Free(Address start) { -#ifdef DEBUG - Isolate::Current()->memory_allocator()->ZapBlock(start, object_size_); -#endif - // We only use the freelists with mark-sweep. - ASSERT(!HEAP->mark_compact_collector()->IsCompacting()); - FreeListNode* node = FreeListNode::FromAddress(start); - node->set_size(heap_, object_size_); - node->set_next(heap_, NULL); - if (head_ == NULL) { - tail_ = head_ = node->address(); +// Allocation on the old space free list. If it succeeds then a new linear +// allocation space has been set up with the top and limit of the space. If +// the allocation fails then NULL is returned, and the caller can perform a GC +// or allocate a new page before retrying. +HeapObject* FreeList::Allocate(int size_in_bytes) { + ASSERT(0 < size_in_bytes); + ASSERT(size_in_bytes <= kMaxBlockSize); + ASSERT(IsAligned(size_in_bytes, kPointerSize)); + // Don't free list allocate if there is linear space available. + ASSERT(owner_->limit() - owner_->top() < size_in_bytes); + + int new_node_size = 0; + FreeListNode* new_node = FindNodeFor(size_in_bytes, &new_node_size); + if (new_node == NULL) return NULL; + + available_ -= new_node_size; + ASSERT(IsVeryLong() || available_ == SumFreeLists()); + + int bytes_left = new_node_size - size_in_bytes; + ASSERT(bytes_left >= 0); + + int old_linear_size = static_cast<int>(owner_->limit() - owner_->top()); + // Mark the old linear allocation area with a free space map so it can be + // skipped when scanning the heap. This also puts it back in the free list + // if it is big enough. + owner_->Free(owner_->top(), old_linear_size); + owner_->heap()->incremental_marking()->OldSpaceStep( + size_in_bytes - old_linear_size); + + // The old-space-step might have finished sweeping and restarted marking. + // Verify that it did not turn the page of the new node into an evacuation + // candidate. + ASSERT(!MarkCompactCollector::IsOnEvacuationCandidate(new_node)); + + const int kThreshold = IncrementalMarking::kAllocatedThreshold; + + // Memory in the linear allocation area is counted as allocated. We may free + // a little of this again immediately - see below. + owner_->Allocate(new_node_size); + + if (bytes_left > kThreshold && + owner_->heap()->incremental_marking()->IsMarkingIncomplete() && + FLAG_incremental_marking_steps) { + int linear_size = owner_->RoundSizeDownToObjectAlignment(kThreshold); + // We don't want to give too large linear areas to the allocator while + // incremental marking is going on, because we won't check again whether + // we want to do another increment until the linear area is used up. + owner_->Free(new_node->address() + size_in_bytes + linear_size, + new_node_size - size_in_bytes - linear_size); + owner_->SetTop(new_node->address() + size_in_bytes, + new_node->address() + size_in_bytes + linear_size); + } else if (bytes_left > 0) { + // Normally we give the rest of the node to the allocator as its new + // linear allocation area. + owner_->SetTop(new_node->address() + size_in_bytes, + new_node->address() + new_node_size); } else { - FreeListNode::FromAddress(tail_)->set_next(heap_, node->address()); - tail_ = node->address(); + // TODO(gc) Try not freeing linear allocation region when bytes_left + // are zero. + owner_->SetTop(NULL, NULL); } - available_ += object_size_; + + return new_node; } -MaybeObject* FixedSizeFreeList::Allocate() { - if (head_ == NULL) { - return Failure::RetryAfterGC(owner_); +static intptr_t CountFreeListItemsInList(FreeListNode* n, Page* p) { + intptr_t sum = 0; + while (n != NULL) { + if (Page::FromAddress(n->address()) == p) { + FreeSpace* free_space = reinterpret_cast<FreeSpace*>(n); + sum += free_space->Size(); + } + n = n->next(); } - - ASSERT(!FLAG_always_compact); // We only use the freelists with mark-sweep. - FreeListNode* node = FreeListNode::FromAddress(head_); - head_ = node->next(heap_); - available_ -= object_size_; - return node; + return sum; } -void FixedSizeFreeList::MarkNodes() { - Address cur_addr = head_; - while (cur_addr != NULL && cur_addr != tail_) { - FreeListNode* cur_node = FreeListNode::FromAddress(cur_addr); - cur_addr = cur_node->next(heap_); - cur_node->SetMark(); +void FreeList::CountFreeListItems(Page* p, intptr_t* sizes) { + sizes[0] = CountFreeListItemsInList(small_list_, p); + sizes[1] = CountFreeListItemsInList(medium_list_, p); + sizes[2] = CountFreeListItemsInList(large_list_, p); + sizes[3] = CountFreeListItemsInList(huge_list_, p); +} + +#ifdef DEBUG +intptr_t FreeList::SumFreeList(FreeListNode* cur) { + intptr_t sum = 0; + while (cur != NULL) { + ASSERT(cur->map() == HEAP->raw_unchecked_free_space_map()); + FreeSpace* cur_as_free_space = reinterpret_cast<FreeSpace*>(cur); + sum += cur_as_free_space->Size(); + cur = cur->next(); } + return sum; } -// ----------------------------------------------------------------------------- -// OldSpace implementation +static const int kVeryLongFreeList = 500; -void OldSpace::PrepareForMarkCompact(bool will_compact) { - // Call prepare of the super class. - PagedSpace::PrepareForMarkCompact(will_compact); - - if (will_compact) { - // Reset relocation info. During a compacting collection, everything in - // the space is considered 'available' and we will rediscover live data - // and waste during the collection. - MCResetRelocationInfo(); - ASSERT(Available() == Capacity()); - } else { - // During a non-compacting collection, everything below the linear - // allocation pointer is considered allocated (everything above is - // available) and we will rediscover available and wasted bytes during - // the collection. - accounting_stats_.AllocateBytes(free_list_.available()); - accounting_stats_.FillWastedBytes(Waste()); - } - // Clear the free list before a full GC---it will be rebuilt afterward. - free_list_.Reset(); +int FreeList::FreeListLength(FreeListNode* cur) { + int length = 0; + while (cur != NULL) { + length++; + cur = cur->next(); + if (length == kVeryLongFreeList) return length; + } + return length; } -void OldSpace::MCCommitRelocationInfo() { - // Update fast allocation info. - allocation_info_.top = mc_forwarding_info_.top; - allocation_info_.limit = mc_forwarding_info_.limit; - ASSERT(allocation_info_.VerifyPagedAllocation()); +bool FreeList::IsVeryLong() { + if (FreeListLength(small_list_) == kVeryLongFreeList) return true; + if (FreeListLength(medium_list_) == kVeryLongFreeList) return true; + if (FreeListLength(large_list_) == kVeryLongFreeList) return true; + if (FreeListLength(huge_list_) == kVeryLongFreeList) return true; + return false; +} - // The space is compacted and we haven't yet built free lists or - // wasted any space. - ASSERT(Waste() == 0); - ASSERT(AvailableFree() == 0); - // Build the free list for the space. - int computed_size = 0; - PageIterator it(this, PageIterator::PAGES_USED_BY_MC); - while (it.has_next()) { - Page* p = it.next(); - // Space below the relocation pointer is allocated. - computed_size += - static_cast<int>(p->AllocationWatermark() - p->ObjectAreaStart()); - if (it.has_next()) { - // Free the space at the top of the page. - int extra_size = - static_cast<int>(p->ObjectAreaEnd() - p->AllocationWatermark()); - if (extra_size > 0) { - int wasted_bytes = free_list_.Free(p->AllocationWatermark(), - extra_size); - // The bytes we have just "freed" to add to the free list were - // already accounted as available. - accounting_stats_.WasteBytes(wasted_bytes); - } - } - } - - // Make sure the computed size - based on the used portion of the pages in - // use - matches the size obtained while computing forwarding addresses. - ASSERT(computed_size == Size()); +// This can take a very long time because it is linear in the number of entries +// on the free list, so it should not be called if FreeListLength returns +// kVeryLongFreeList. +intptr_t FreeList::SumFreeLists() { + intptr_t sum = SumFreeList(small_list_); + sum += SumFreeList(medium_list_); + sum += SumFreeList(large_list_); + sum += SumFreeList(huge_list_); + return sum; } +#endif + +// ----------------------------------------------------------------------------- +// OldSpace implementation bool NewSpace::ReserveSpace(int bytes) { // We can't reliably unpack a partial snapshot that needs more new space @@ -2050,200 +1917,119 @@ bool NewSpace::ReserveSpace(int bytes) { } -void PagedSpace::FreePages(Page* prev, Page* last) { - if (last == AllocationTopPage()) { - // Pages are already at the end of used pages. - return; +void PagedSpace::PrepareForMarkCompact() { + // We don't have a linear allocation area while sweeping. It will be restored + // on the first allocation after the sweep. + // Mark the old linear allocation area with a free space map so it can be + // skipped when scanning the heap. + int old_linear_size = static_cast<int>(limit() - top()); + Free(top(), old_linear_size); + SetTop(NULL, NULL); + + // Stop lazy sweeping and clear marking bits for unswept pages. + if (first_unswept_page_ != NULL) { + Page* last = last_unswept_page_; + Page* p = first_unswept_page_; + do { + // Do not use ShouldBeSweptLazily predicate here. + // New evacuation candidates were selected but they still have + // to be swept before collection starts. + if (!p->WasSwept()) { + Bitmap::Clear(p); + if (FLAG_gc_verbose) { + PrintF("Sweeping 0x%" V8PRIxPTR " lazily abandoned.\n", + reinterpret_cast<intptr_t>(p)); + } + } + p = p->next_page(); + } while (p != last); } + first_unswept_page_ = last_unswept_page_ = Page::FromAddress(NULL); - Page* first = NULL; - - // Remove pages from the list. - if (prev == NULL) { - first = first_page_; - first_page_ = last->next_page(); - } else { - first = prev->next_page(); - heap()->isolate()->memory_allocator()->SetNextPage( - prev, last->next_page()); - } + // Clear the free list before a full GC---it will be rebuilt afterward. + free_list_.Reset(); +} - // Attach it after the last page. - heap()->isolate()->memory_allocator()->SetNextPage(last_page_, first); - last_page_ = last; - heap()->isolate()->memory_allocator()->SetNextPage(last, NULL); - // Clean them up. - do { - first->InvalidateWatermark(true); - first->SetAllocationWatermark(first->ObjectAreaStart()); - first->SetCachedAllocationWatermark(first->ObjectAreaStart()); - first->SetRegionMarks(Page::kAllRegionsCleanMarks); - first = first->next_page(); - } while (first != NULL); - - // Order of pages in this space might no longer be consistent with - // order of pages in chunks. - page_list_is_chunk_ordered_ = false; -} - - -void PagedSpace::RelinkPageListInChunkOrder(bool deallocate_blocks) { - const bool add_to_freelist = true; - - // Mark used and unused pages to properly fill unused pages - // after reordering. - PageIterator all_pages_iterator(this, PageIterator::ALL_PAGES); - Page* last_in_use = AllocationTopPage(); - bool in_use = true; - - while (all_pages_iterator.has_next()) { - Page* p = all_pages_iterator.next(); - p->SetWasInUseBeforeMC(in_use); - if (p == last_in_use) { - // We passed a page containing allocation top. All consequent - // pages are not used. - in_use = false; - } - } +bool PagedSpace::ReserveSpace(int size_in_bytes) { + ASSERT(size_in_bytes <= Page::kMaxHeapObjectSize); + ASSERT(size_in_bytes == RoundSizeDownToObjectAlignment(size_in_bytes)); + Address current_top = allocation_info_.top; + Address new_top = current_top + size_in_bytes; + if (new_top <= allocation_info_.limit) return true; - if (page_list_is_chunk_ordered_) return; + HeapObject* new_area = free_list_.Allocate(size_in_bytes); + if (new_area == NULL) new_area = SlowAllocateRaw(size_in_bytes); + if (new_area == NULL) return false; - Page* new_last_in_use = Page::FromAddress(NULL); - heap()->isolate()->memory_allocator()->RelinkPageListInChunkOrder( - this, &first_page_, &last_page_, &new_last_in_use); - ASSERT(new_last_in_use->is_valid()); + int old_linear_size = static_cast<int>(limit() - top()); + // Mark the old linear allocation area with a free space so it can be + // skipped when scanning the heap. This also puts it back in the free list + // if it is big enough. + Free(top(), old_linear_size); - if (new_last_in_use != last_in_use) { - // Current allocation top points to a page which is now in the middle - // of page list. We should move allocation top forward to the new last - // used page so various object iterators will continue to work properly. - int size_in_bytes = static_cast<int>(PageAllocationLimit(last_in_use) - - last_in_use->AllocationTop()); + SetTop(new_area->address(), new_area->address() + size_in_bytes); + Allocate(size_in_bytes); + return true; +} - last_in_use->SetAllocationWatermark(last_in_use->AllocationTop()); - if (size_in_bytes > 0) { - Address start = last_in_use->AllocationTop(); - if (deallocate_blocks) { - accounting_stats_.AllocateBytes(size_in_bytes); - DeallocateBlock(start, size_in_bytes, add_to_freelist); - } else { - heap()->CreateFillerObjectAt(start, size_in_bytes); - } - } - // New last in use page was in the middle of the list before - // sorting so it full. - SetTop(new_last_in_use->AllocationTop()); +// You have to call this last, since the implementation from PagedSpace +// doesn't know that memory was 'promised' to large object space. +bool LargeObjectSpace::ReserveSpace(int bytes) { + return heap()->OldGenerationSpaceAvailable() >= bytes; +} - ASSERT(AllocationTopPage() == new_last_in_use); - ASSERT(AllocationTopPage()->WasInUseBeforeMC()); - } - PageIterator pages_in_use_iterator(this, PageIterator::PAGES_IN_USE); - while (pages_in_use_iterator.has_next()) { - Page* p = pages_in_use_iterator.next(); - if (!p->WasInUseBeforeMC()) { - // Empty page is in the middle of a sequence of used pages. - // Allocate it as a whole and deallocate immediately. - int size_in_bytes = static_cast<int>(PageAllocationLimit(p) - - p->ObjectAreaStart()); +bool PagedSpace::AdvanceSweeper(intptr_t bytes_to_sweep) { + if (IsSweepingComplete()) return true; - p->SetAllocationWatermark(p->ObjectAreaStart()); - Address start = p->ObjectAreaStart(); - if (deallocate_blocks) { - accounting_stats_.AllocateBytes(size_in_bytes); - DeallocateBlock(start, size_in_bytes, add_to_freelist); - } else { - heap()->CreateFillerObjectAt(start, size_in_bytes); + intptr_t freed_bytes = 0; + Page* last = last_unswept_page_; + Page* p = first_unswept_page_; + do { + Page* next_page = p->next_page(); + if (ShouldBeSweptLazily(p)) { + if (FLAG_gc_verbose) { + PrintF("Sweeping 0x%" V8PRIxPTR " lazily advanced.\n", + reinterpret_cast<intptr_t>(p)); } + freed_bytes += MarkCompactCollector::SweepConservatively(this, p); } + p = next_page; + } while (p != last && freed_bytes < bytes_to_sweep); + + if (p == last) { + last_unswept_page_ = first_unswept_page_ = Page::FromAddress(NULL); + } else { + first_unswept_page_ = p; } - page_list_is_chunk_ordered_ = true; -} + heap()->LowerOldGenLimits(freed_bytes); + heap()->FreeQueuedChunks(); -void PagedSpace::PrepareForMarkCompact(bool will_compact) { - if (will_compact) { - RelinkPageListInChunkOrder(false); - } + return IsSweepingComplete(); } -bool PagedSpace::ReserveSpace(int bytes) { - Address limit = allocation_info_.limit; - Address top = allocation_info_.top; - if (limit - top >= bytes) return true; - - // There wasn't enough space in the current page. Lets put the rest - // of the page on the free list and start a fresh page. - PutRestOfCurrentPageOnFreeList(TopPageOf(allocation_info_)); - - Page* reserved_page = TopPageOf(allocation_info_); - int bytes_left_to_reserve = bytes; - while (bytes_left_to_reserve > 0) { - if (!reserved_page->next_page()->is_valid()) { - if (heap()->OldGenerationAllocationLimitReached()) return false; - Expand(reserved_page); - } - bytes_left_to_reserve -= Page::kPageSize; - reserved_page = reserved_page->next_page(); - if (!reserved_page->is_valid()) return false; - } - ASSERT(TopPageOf(allocation_info_)->next_page()->is_valid()); - TopPageOf(allocation_info_)->next_page()->InvalidateWatermark(true); - SetAllocationInfo(&allocation_info_, - TopPageOf(allocation_info_)->next_page()); - return true; -} +void PagedSpace::EvictEvacuationCandidatesFromFreeLists() { + if (allocation_info_.top >= allocation_info_.limit) return; + if (Page::FromAddress(allocation_info_.top)->IsEvacuationCandidate()) { + // Create filler object to keep page iterable if it was iterable. + int remaining = + static_cast<int>(allocation_info_.limit - allocation_info_.top); + heap()->CreateFillerObjectAt(allocation_info_.top, remaining); -// You have to call this last, since the implementation from PagedSpace -// doesn't know that memory was 'promised' to large object space. -bool LargeObjectSpace::ReserveSpace(int bytes) { - return heap()->OldGenerationSpaceAvailable() >= bytes; + allocation_info_.top = NULL; + allocation_info_.limit = NULL; + } } -// Slow case for normal allocation. Try in order: (1) allocate in the next -// page in the space, (2) allocate off the space's free list, (3) expand the -// space, (4) fail. -HeapObject* OldSpace::SlowAllocateRaw(int size_in_bytes) { - // Linear allocation in this space has failed. If there is another page - // in the space, move to that page and allocate there. This allocation - // should succeed (size_in_bytes should not be greater than a page's - // object area size). - Page* current_page = TopPageOf(allocation_info_); - if (current_page->next_page()->is_valid()) { - return AllocateInNextPage(current_page, size_in_bytes); - } - - // There is no next page in this space. Try free list allocation unless that - // is currently forbidden. - if (!heap()->linear_allocation()) { - int wasted_bytes; - Object* result; - MaybeObject* maybe = free_list_.Allocate(size_in_bytes, &wasted_bytes); - accounting_stats_.WasteBytes(wasted_bytes); - if (maybe->ToObject(&result)) { - accounting_stats_.AllocateBytes(size_in_bytes); - - HeapObject* obj = HeapObject::cast(result); - Page* p = Page::FromAddress(obj->address()); - - if (obj->address() >= p->AllocationWatermark()) { - // There should be no hole between the allocation watermark - // and allocated object address. - // Memory above the allocation watermark was not swept and - // might contain garbage pointers to new space. - ASSERT(obj->address() == p->AllocationWatermark()); - p->SetAllocationWatermark(obj->address() + size_in_bytes); - } - - return obj; - } - } +HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) { + // Allocation in this space has failed. // Free list allocation failed and there is no next page. Fail if we have // hit the old generation size limit that should cause a garbage @@ -2253,61 +2039,30 @@ HeapObject* OldSpace::SlowAllocateRaw(int size_in_bytes) { return NULL; } - // Try to expand the space and allocate in the new next page. - ASSERT(!current_page->next_page()->is_valid()); - if (Expand(current_page)) { - return AllocateInNextPage(current_page, size_in_bytes); - } + // If there are unswept pages advance lazy sweeper. + if (first_unswept_page_->is_valid()) { + AdvanceSweeper(size_in_bytes); - // Finally, fail. - return NULL; -} + // Retry the free list allocation. + HeapObject* object = free_list_.Allocate(size_in_bytes); + if (object != NULL) return object; + if (!IsSweepingComplete()) { + AdvanceSweeper(kMaxInt); -void OldSpace::PutRestOfCurrentPageOnFreeList(Page* current_page) { - current_page->SetAllocationWatermark(allocation_info_.top); - int free_size = - static_cast<int>(current_page->ObjectAreaEnd() - allocation_info_.top); - if (free_size > 0) { - int wasted_bytes = free_list_.Free(allocation_info_.top, free_size); - accounting_stats_.WasteBytes(wasted_bytes); + // Retry the free list allocation. + object = free_list_.Allocate(size_in_bytes); + if (object != NULL) return object; + } } -} - -void FixedSpace::PutRestOfCurrentPageOnFreeList(Page* current_page) { - current_page->SetAllocationWatermark(allocation_info_.top); - int free_size = - static_cast<int>(current_page->ObjectAreaEnd() - allocation_info_.top); - // In the fixed space free list all the free list items have the right size. - // We use up the rest of the page while preserving this invariant. - while (free_size >= object_size_in_bytes_) { - free_list_.Free(allocation_info_.top); - allocation_info_.top += object_size_in_bytes_; - free_size -= object_size_in_bytes_; - accounting_stats_.WasteBytes(object_size_in_bytes_); + // Try to expand the space and allocate in the new next page. + if (Expand()) { + return free_list_.Allocate(size_in_bytes); } -} - -// Add the block at the top of the page to the space's free list, set the -// allocation info to the next page (assumed to be one), and allocate -// linearly there. -HeapObject* OldSpace::AllocateInNextPage(Page* current_page, - int size_in_bytes) { - ASSERT(current_page->next_page()->is_valid()); - Page* next_page = current_page->next_page(); - next_page->ClearGCFields(); - PutRestOfCurrentPageOnFreeList(current_page); - SetAllocationInfo(&allocation_info_, next_page); - return AllocateLinearly(&allocation_info_, size_in_bytes); -} - - -void OldSpace::DeallocateBlock(Address start, - int size_in_bytes, - bool add_to_freelist) { - Free(start, size_in_bytes, add_to_freelist); + // Finally, fail. + return NULL; } @@ -2413,7 +2168,7 @@ static void CollectCommentStatistics(Isolate* isolate, RelocIterator* it) { void PagedSpace::CollectCodeStatistics() { Isolate* isolate = heap()->isolate(); HeapObjectIterator obj_it(this); - for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) { + for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) { if (obj->IsCode()) { Code* code = Code::cast(obj); isolate->code_kind_statistics()[code->kind()] += code->Size(); @@ -2438,16 +2193,17 @@ void PagedSpace::CollectCodeStatistics() { } -void OldSpace::ReportStatistics() { +void PagedSpace::ReportStatistics() { int pct = static_cast<int>(Available() * 100 / Capacity()); PrintF(" capacity: %" V8_PTR_PREFIX "d" ", waste: %" V8_PTR_PREFIX "d" ", available: %" V8_PTR_PREFIX "d, %%%d\n", Capacity(), Waste(), Available(), pct); + if (was_swept_conservatively_) return; ClearHistograms(); HeapObjectIterator obj_it(this); - for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) + for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) CollectHistogramInfo(obj); ReportHistogram(true); } @@ -2456,192 +2212,28 @@ void OldSpace::ReportStatistics() { // ----------------------------------------------------------------------------- // FixedSpace implementation -void FixedSpace::PrepareForMarkCompact(bool will_compact) { +void FixedSpace::PrepareForMarkCompact() { // Call prepare of the super class. - PagedSpace::PrepareForMarkCompact(will_compact); - - if (will_compact) { - // Reset relocation info. - MCResetRelocationInfo(); + PagedSpace::PrepareForMarkCompact(); - // During a compacting collection, everything in the space is considered - // 'available' (set by the call to MCResetRelocationInfo) and we will - // rediscover live and wasted bytes during the collection. - ASSERT(Available() == Capacity()); - } else { - // During a non-compacting collection, everything below the linear - // allocation pointer except wasted top-of-page blocks is considered - // allocated and we will rediscover available bytes during the - // collection. - accounting_stats_.AllocateBytes(free_list_.available()); - } + // During a non-compacting collection, everything below the linear + // allocation pointer except wasted top-of-page blocks is considered + // allocated and we will rediscover available bytes during the + // collection. + accounting_stats_.AllocateBytes(free_list_.available()); // Clear the free list before a full GC---it will be rebuilt afterward. free_list_.Reset(); } -void FixedSpace::MCCommitRelocationInfo() { - // Update fast allocation info. - allocation_info_.top = mc_forwarding_info_.top; - allocation_info_.limit = mc_forwarding_info_.limit; - ASSERT(allocation_info_.VerifyPagedAllocation()); - - // The space is compacted and we haven't yet wasted any space. - ASSERT(Waste() == 0); - - // Update allocation_top of each page in use and compute waste. - int computed_size = 0; - PageIterator it(this, PageIterator::PAGES_USED_BY_MC); - while (it.has_next()) { - Page* page = it.next(); - Address page_top = page->AllocationTop(); - computed_size += static_cast<int>(page_top - page->ObjectAreaStart()); - if (it.has_next()) { - accounting_stats_.WasteBytes( - static_cast<int>(page->ObjectAreaEnd() - page_top)); - page->SetAllocationWatermark(page_top); - } - } - - // Make sure the computed size - based on the used portion of the - // pages in use - matches the size we adjust during allocation. - ASSERT(computed_size == Size()); -} - - -// Slow case for normal allocation. Try in order: (1) allocate in the next -// page in the space, (2) allocate off the space's free list, (3) expand the -// space, (4) fail. -HeapObject* FixedSpace::SlowAllocateRaw(int size_in_bytes) { - ASSERT_EQ(object_size_in_bytes_, size_in_bytes); - // Linear allocation in this space has failed. If there is another page - // in the space, move to that page and allocate there. This allocation - // should succeed. - Page* current_page = TopPageOf(allocation_info_); - if (current_page->next_page()->is_valid()) { - return AllocateInNextPage(current_page, size_in_bytes); - } - - // There is no next page in this space. Try free list allocation unless - // that is currently forbidden. The fixed space free list implicitly assumes - // that all free blocks are of the fixed size. - if (!heap()->linear_allocation()) { - Object* result; - MaybeObject* maybe = free_list_.Allocate(); - if (maybe->ToObject(&result)) { - accounting_stats_.AllocateBytes(size_in_bytes); - HeapObject* obj = HeapObject::cast(result); - Page* p = Page::FromAddress(obj->address()); - - if (obj->address() >= p->AllocationWatermark()) { - // There should be no hole between the allocation watermark - // and allocated object address. - // Memory above the allocation watermark was not swept and - // might contain garbage pointers to new space. - ASSERT(obj->address() == p->AllocationWatermark()); - p->SetAllocationWatermark(obj->address() + size_in_bytes); - } - - return obj; - } - } - - // Free list allocation failed and there is no next page. Fail if we have - // hit the old generation size limit that should cause a garbage - // collection. - if (!heap()->always_allocate() && - heap()->OldGenerationAllocationLimitReached()) { - return NULL; - } - - // Try to expand the space and allocate in the new next page. - ASSERT(!current_page->next_page()->is_valid()); - if (Expand(current_page)) { - return AllocateInNextPage(current_page, size_in_bytes); - } - - // Finally, fail. - return NULL; -} - - -// Move to the next page (there is assumed to be one) and allocate there. -// The top of page block is always wasted, because it is too small to hold a -// map. -HeapObject* FixedSpace::AllocateInNextPage(Page* current_page, - int size_in_bytes) { - ASSERT(current_page->next_page()->is_valid()); - ASSERT(allocation_info_.top == PageAllocationLimit(current_page)); - ASSERT_EQ(object_size_in_bytes_, size_in_bytes); - Page* next_page = current_page->next_page(); - next_page->ClearGCFields(); - current_page->SetAllocationWatermark(allocation_info_.top); - accounting_stats_.WasteBytes(page_extra_); - SetAllocationInfo(&allocation_info_, next_page); - return AllocateLinearly(&allocation_info_, size_in_bytes); -} - - -void FixedSpace::DeallocateBlock(Address start, - int size_in_bytes, - bool add_to_freelist) { - // Free-list elements in fixed space are assumed to have a fixed size. - // We break the free block into chunks and add them to the free list - // individually. - int size = object_size_in_bytes(); - ASSERT(size_in_bytes % size == 0); - Address end = start + size_in_bytes; - for (Address a = start; a < end; a += size) { - Free(a, add_to_freelist); - } -} - - -#ifdef DEBUG -void FixedSpace::ReportStatistics() { - int pct = static_cast<int>(Available() * 100 / Capacity()); - PrintF(" capacity: %" V8_PTR_PREFIX "d" - ", waste: %" V8_PTR_PREFIX "d" - ", available: %" V8_PTR_PREFIX "d, %%%d\n", - Capacity(), Waste(), Available(), pct); - - ClearHistograms(); - HeapObjectIterator obj_it(this); - for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) - CollectHistogramInfo(obj); - ReportHistogram(false); -} -#endif - - // ----------------------------------------------------------------------------- // MapSpace implementation -void MapSpace::PrepareForMarkCompact(bool will_compact) { - // Call prepare of the super class. - FixedSpace::PrepareForMarkCompact(will_compact); - - if (will_compact) { - // Initialize map index entry. - int page_count = 0; - PageIterator it(this, PageIterator::ALL_PAGES); - while (it.has_next()) { - ASSERT_MAP_PAGE_INDEX(page_count); - - Page* p = it.next(); - ASSERT(p->mc_page_index == page_count); - - page_addresses_[page_count++] = p->address(); - } - } -} - - #ifdef DEBUG void MapSpace::VerifyObject(HeapObject* object) { // The object should be a map or a free-list node. - ASSERT(object->IsMap() || object->IsByteArray()); + ASSERT(object->IsMap() || object->IsFreeSpace()); } #endif @@ -2662,107 +2254,40 @@ void CellSpace::VerifyObject(HeapObject* object) { // LargeObjectIterator LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space) { - current_ = space->first_chunk_; + current_ = space->first_page_; size_func_ = NULL; } LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space, HeapObjectCallback size_func) { - current_ = space->first_chunk_; + current_ = space->first_page_; size_func_ = size_func; } -HeapObject* LargeObjectIterator::next() { +HeapObject* LargeObjectIterator::Next() { if (current_ == NULL) return NULL; HeapObject* object = current_->GetObject(); - current_ = current_->next(); + current_ = current_->next_page(); return object; } // ----------------------------------------------------------------------------- -// LargeObjectChunk - -LargeObjectChunk* LargeObjectChunk::New(int size_in_bytes, - Executability executable) { - size_t requested = ChunkSizeFor(size_in_bytes); - size_t size; - size_t guard_size = (executable == EXECUTABLE) ? Page::kPageSize : 0; - Isolate* isolate = Isolate::Current(); - void* mem = isolate->memory_allocator()->AllocateRawMemory( - requested + guard_size, &size, executable); - if (mem == NULL) return NULL; - - // The start of the chunk may be overlayed with a page so we have to - // make sure that the page flags fit in the size field. - ASSERT((size & Page::kPageFlagMask) == 0); - - LOG(isolate, NewEvent("LargeObjectChunk", mem, size)); - if (size < requested + guard_size) { - isolate->memory_allocator()->FreeRawMemory( - mem, size, executable); - LOG(isolate, DeleteEvent("LargeObjectChunk", mem)); - return NULL; - } - - if (guard_size != 0) { - OS::Guard(mem, guard_size); - size -= guard_size; - mem = static_cast<Address>(mem) + guard_size; - } - - ObjectSpace space = (executable == EXECUTABLE) - ? kObjectSpaceCodeSpace - : kObjectSpaceLoSpace; - isolate->memory_allocator()->PerformAllocationCallback( - space, kAllocationActionAllocate, size); - - LargeObjectChunk* chunk = reinterpret_cast<LargeObjectChunk*>(mem); - chunk->size_ = size; - chunk->GetPage()->heap_ = isolate->heap(); - return chunk; -} - - -void LargeObjectChunk::Free(Executability executable) { - size_t guard_size = (executable == EXECUTABLE) ? Page::kPageSize : 0; - ObjectSpace space = - (executable == EXECUTABLE) ? kObjectSpaceCodeSpace : kObjectSpaceLoSpace; - // Do not access instance fields after FreeRawMemory! - Address my_address = address(); - size_t my_size = size(); - Isolate* isolate = GetPage()->heap_->isolate(); - MemoryAllocator* a = isolate->memory_allocator(); - a->FreeRawMemory(my_address - guard_size, my_size + guard_size, executable); - a->PerformAllocationCallback(space, kAllocationActionFree, my_size); - LOG(isolate, DeleteEvent("LargeObjectChunk", my_address)); -} - - -int LargeObjectChunk::ChunkSizeFor(int size_in_bytes) { - int os_alignment = static_cast<int>(OS::AllocateAlignment()); - if (os_alignment < Page::kPageSize) { - size_in_bytes += (Page::kPageSize - os_alignment); - } - return size_in_bytes + Page::kObjectStartOffset; -} - -// ----------------------------------------------------------------------------- // LargeObjectSpace LargeObjectSpace::LargeObjectSpace(Heap* heap, AllocationSpace id) : Space(heap, id, NOT_EXECUTABLE), // Managed on a per-allocation basis - first_chunk_(NULL), + first_page_(NULL), size_(0), page_count_(0), objects_size_(0) {} bool LargeObjectSpace::Setup() { - first_chunk_ = NULL; + first_page_ = NULL; size_ = 0; page_count_ = 0; objects_size_ = 0; @@ -2771,20 +2296,22 @@ bool LargeObjectSpace::Setup() { void LargeObjectSpace::TearDown() { - while (first_chunk_ != NULL) { - LargeObjectChunk* chunk = first_chunk_; - first_chunk_ = first_chunk_->next(); - chunk->Free(chunk->GetPage()->PageExecutability()); + while (first_page_ != NULL) { + LargePage* page = first_page_; + first_page_ = first_page_->next_page(); + LOG(heap()->isolate(), DeleteEvent("LargeObjectChunk", page->address())); + + ObjectSpace space = static_cast<ObjectSpace>(1 << identity()); + heap()->isolate()->memory_allocator()->PerformAllocationCallback( + space, kAllocationActionFree, page->size()); + heap()->isolate()->memory_allocator()->Free(page); } Setup(); } -MaybeObject* LargeObjectSpace::AllocateRawInternal(int requested_size, - int object_size, - Executability executable) { - ASSERT(0 < object_size && object_size <= requested_size); - +MaybeObject* LargeObjectSpace::AllocateRaw(int object_size, + Executability executable) { // Check if we want to force a GC before growing the old space further. // If so, fail the allocation. if (!heap()->always_allocate() && @@ -2792,75 +2319,42 @@ MaybeObject* LargeObjectSpace::AllocateRawInternal(int requested_size, return Failure::RetryAfterGC(identity()); } - LargeObjectChunk* chunk = LargeObjectChunk::New(requested_size, executable); - if (chunk == NULL) { - return Failure::RetryAfterGC(identity()); - } + LargePage* page = heap()->isolate()->memory_allocator()-> + AllocateLargePage(object_size, executable, this); + if (page == NULL) return Failure::RetryAfterGC(identity()); + ASSERT(page->body_size() >= object_size); - size_ += static_cast<int>(chunk->size()); - objects_size_ += requested_size; + size_ += static_cast<int>(page->size()); + objects_size_ += object_size; page_count_++; - chunk->set_next(first_chunk_); - first_chunk_ = chunk; - - // Initialize page header. - Page* page = chunk->GetPage(); - Address object_address = page->ObjectAreaStart(); - - // Clear the low order bit of the second word in the page to flag it as a - // large object page. If the chunk_size happened to be written there, its - // low order bit should already be clear. - page->SetIsLargeObjectPage(true); - page->SetPageExecutability(executable); - page->SetRegionMarks(Page::kAllRegionsCleanMarks); - return HeapObject::FromAddress(object_address); -} - - -MaybeObject* LargeObjectSpace::AllocateRawCode(int size_in_bytes) { - ASSERT(0 < size_in_bytes); - return AllocateRawInternal(size_in_bytes, - size_in_bytes, - EXECUTABLE); -} - + page->set_next_page(first_page_); + first_page_ = page; -MaybeObject* LargeObjectSpace::AllocateRawFixedArray(int size_in_bytes) { - ASSERT(0 < size_in_bytes); - return AllocateRawInternal(size_in_bytes, - size_in_bytes, - NOT_EXECUTABLE); -} - - -MaybeObject* LargeObjectSpace::AllocateRaw(int size_in_bytes) { - ASSERT(0 < size_in_bytes); - return AllocateRawInternal(size_in_bytes, - size_in_bytes, - NOT_EXECUTABLE); + heap()->incremental_marking()->OldSpaceStep(object_size); + return page->GetObject(); } // GC support MaybeObject* LargeObjectSpace::FindObject(Address a) { - for (LargeObjectChunk* chunk = first_chunk_; - chunk != NULL; - chunk = chunk->next()) { - Address chunk_address = chunk->address(); - if (chunk_address <= a && a < chunk_address + chunk->size()) { - return chunk->GetObject(); + for (LargePage* page = first_page_; + page != NULL; + page = page->next_page()) { + Address page_address = page->address(); + if (page_address <= a && a < page_address + page->size()) { + return page->GetObject(); } } return Failure::Exception(); } -LargeObjectChunk* LargeObjectSpace::FindChunkContainingPc(Address pc) { +LargePage* LargeObjectSpace::FindPageContainingPc(Address pc) { // TODO(853): Change this implementation to only find executable // chunks and use some kind of hash-based approach to speed it up. - for (LargeObjectChunk* chunk = first_chunk_; + for (LargePage* chunk = first_page_; chunk != NULL; - chunk = chunk->next()) { + chunk = chunk->next_page()) { Address chunk_address = chunk->address(); if (chunk_address <= pc && pc < chunk_address + chunk->size()) { return chunk; @@ -2870,112 +2364,57 @@ LargeObjectChunk* LargeObjectSpace::FindChunkContainingPc(Address pc) { } -void LargeObjectSpace::IterateDirtyRegions(ObjectSlotCallback copy_object) { - LargeObjectIterator it(this); - for (HeapObject* object = it.next(); object != NULL; object = it.next()) { - // We only have code, sequential strings, or fixed arrays in large - // object space, and only fixed arrays can possibly contain pointers to - // the young generation. - if (object->IsFixedArray()) { - Page* page = Page::FromAddress(object->address()); - uint32_t marks = page->GetRegionMarks(); - uint32_t newmarks = Page::kAllRegionsCleanMarks; - - if (marks != Page::kAllRegionsCleanMarks) { - // For a large page a single dirty mark corresponds to several - // regions (modulo 32). So we treat a large page as a sequence of - // normal pages of size Page::kPageSize having same dirty marks - // and subsequently iterate dirty regions on each of these pages. - Address start = object->address(); - Address end = page->ObjectAreaEnd(); - Address object_end = start + object->Size(); - - // Iterate regions of the first normal page covering object. - uint32_t first_region_number = page->GetRegionNumberForAddress(start); - newmarks |= - heap()->IterateDirtyRegions(marks >> first_region_number, - start, - end, - &Heap::IteratePointersInDirtyRegion, - copy_object) << first_region_number; - - start = end; - end = start + Page::kPageSize; - while (end <= object_end) { - // Iterate next 32 regions. - newmarks |= - heap()->IterateDirtyRegions(marks, - start, - end, - &Heap::IteratePointersInDirtyRegion, - copy_object); - start = end; - end = start + Page::kPageSize; - } - - if (start != object_end) { - // Iterate the last piece of an object which is less than - // Page::kPageSize. - newmarks |= - heap()->IterateDirtyRegions(marks, - start, - object_end, - &Heap::IteratePointersInDirtyRegion, - copy_object); - } - - page->SetRegionMarks(newmarks); - } - } - } -} - - void LargeObjectSpace::FreeUnmarkedObjects() { - LargeObjectChunk* previous = NULL; - LargeObjectChunk* current = first_chunk_; + LargePage* previous = NULL; + LargePage* current = first_page_; while (current != NULL) { HeapObject* object = current->GetObject(); - if (object->IsMarked()) { - object->ClearMark(); - heap()->mark_compact_collector()->tracer()->decrement_marked_count(); + // Can this large page contain pointers to non-trivial objects. No other + // pointer object is this big. + bool is_pointer_object = object->IsFixedArray(); + MarkBit mark_bit = Marking::MarkBitFrom(object); + if (mark_bit.Get()) { + mark_bit.Clear(); + MemoryChunk::IncrementLiveBytes(object->address(), -object->Size()); previous = current; - current = current->next(); + current = current->next_page(); } else { + LargePage* page = current; // Cut the chunk out from the chunk list. - LargeObjectChunk* current_chunk = current; - current = current->next(); + current = current->next_page(); if (previous == NULL) { - first_chunk_ = current; + first_page_ = current; } else { - previous->set_next(current); + previous->set_next_page(current); } // Free the chunk. heap()->mark_compact_collector()->ReportDeleteIfNeeded( object, heap()->isolate()); - LiveObjectList::ProcessNonLive(object); - - size_ -= static_cast<int>(current_chunk->size()); + size_ -= static_cast<int>(page->size()); objects_size_ -= object->Size(); page_count_--; - current_chunk->Free(current_chunk->GetPage()->PageExecutability()); + + if (is_pointer_object) { + heap()->QueueMemoryChunkForFree(page); + } else { + heap()->isolate()->memory_allocator()->Free(page); + } } } + heap()->FreeQueuedChunks(); } bool LargeObjectSpace::Contains(HeapObject* object) { Address address = object->address(); - if (heap()->new_space()->Contains(address)) { - return false; - } - Page* page = Page::FromAddress(address); + MemoryChunk* chunk = MemoryChunk::FromAddress(address); + + bool owned = (chunk->owner() == this); - SLOW_ASSERT(!page->IsLargeObjectPage() - || !FindObject(address)->IsFailure()); + SLOW_ASSERT(!owned || !FindObject(address)->IsFailure()); - return page->IsLargeObjectPage(); + return owned; } @@ -2983,9 +2422,9 @@ bool LargeObjectSpace::Contains(HeapObject* object) { // We do not assume that the large object iterator works, because it depends // on the invariants we are checking during verification. void LargeObjectSpace::Verify() { - for (LargeObjectChunk* chunk = first_chunk_; + for (LargePage* chunk = first_page_; chunk != NULL; - chunk = chunk->next()) { + chunk = chunk->next_page()) { // Each chunk contains an object that starts at the large object page's // object area start. HeapObject* object = chunk->GetObject(); @@ -3015,9 +2454,6 @@ void LargeObjectSpace::Verify() { object->Size(), &code_visitor); } else if (object->IsFixedArray()) { - // We loop over fixed arrays ourselves, rather then using the visitor, - // because the visitor doesn't support the start/offset iteration - // needed for IsRegionDirty. FixedArray* array = FixedArray::cast(object); for (int j = 0; j < array->length(); j++) { Object* element = array->get(j); @@ -3025,13 +2461,6 @@ void LargeObjectSpace::Verify() { HeapObject* element_object = HeapObject::cast(element); ASSERT(heap()->Contains(element_object)); ASSERT(element_object->map()->IsMap()); - if (heap()->InNewSpace(element_object)) { - Address array_addr = object->address(); - Address element_addr = array_addr + FixedArray::kHeaderSize + - j * kPointerSize; - - ASSERT(Page::FromAddress(array_addr)->IsRegionDirty(element_addr)); - } } } } @@ -3041,7 +2470,7 @@ void LargeObjectSpace::Verify() { void LargeObjectSpace::Print() { LargeObjectIterator it(this); - for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) { + for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) { obj->Print(); } } @@ -3052,7 +2481,7 @@ void LargeObjectSpace::ReportStatistics() { int num_objects = 0; ClearHistograms(); LargeObjectIterator it(this); - for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) { + for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) { num_objects++; CollectHistogramInfo(obj); } @@ -3066,13 +2495,38 @@ void LargeObjectSpace::ReportStatistics() { void LargeObjectSpace::CollectCodeStatistics() { Isolate* isolate = heap()->isolate(); LargeObjectIterator obj_it(this); - for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) { + for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) { if (obj->IsCode()) { Code* code = Code::cast(obj); isolate->code_kind_statistics()[code->kind()] += code->Size(); } } } + + +void Page::Print() { + // Make a best-effort to print the objects in the page. + PrintF("Page@%p in %s\n", + this->address(), + AllocationSpaceName(this->owner()->identity())); + printf(" --------------------------------------\n"); + HeapObjectIterator objects(this, heap()->GcSafeSizeOfOldObjectFunction()); + unsigned mark_size = 0; + for (HeapObject* object = objects.Next(); + object != NULL; + object = objects.Next()) { + bool is_marked = Marking::MarkBitFrom(object).Get(); + PrintF(" %c ", (is_marked ? '!' : ' ')); // Indent a little. + if (is_marked) { + mark_size += heap()->GcSafeSizeOfOldObjectFunction()(object); + } + object->ShortPrint(); + PrintF("\n"); + } + printf(" --------------------------------------\n"); + printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes()); +} + #endif // DEBUG } } // namespace v8::internal |