diff options
Diffstat (limited to 'deps/v8/src/spaces.cc')
| -rw-r--r-- | deps/v8/src/spaces.cc | 2931 |
1 files changed, 1741 insertions, 1190 deletions
diff --git a/deps/v8/src/spaces.cc b/deps/v8/src/spaces.cc index 2aaca5b74..97c6d2ac1 100644 --- a/deps/v8/src/spaces.cc +++ b/deps/v8/src/spaces.cc @@ -35,66 +35,52 @@ 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) { - // 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); + Initialize(space->bottom(), space->top(), NULL); } HeapObjectIterator::HeapObjectIterator(PagedSpace* space, HeapObjectCallback 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); + 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); } HeapObjectIterator::HeapObjectIterator(Page* page, HeapObjectCallback size_func) { - 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()); + Initialize(page->ObjectAreaStart(), page->AllocationTop(), size_func); +} - space_ = space; + +void HeapObjectIterator::Initialize(Address cur, Address end, + HeapObjectCallback size_f) { cur_addr_ = cur; - cur_end_ = end; - page_mode_ = mode; + end_addr_ = end; + end_page_ = Page::FromAllocationTop(end); size_func_ = size_f; + Page* p = Page::FromAllocationTop(cur_addr_); + cur_limit_ = (p == end_page_) ? end_addr_ : p->AllocationTop(); #ifdef DEBUG Verify(); @@ -102,35 +88,63 @@ void HeapObjectIterator::Initialize(PagedSpace* space, } -// 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()); - } +HeapObject* HeapObjectIterator::FromNextPage() { + if (cur_addr_ == end_addr_) return NULL; + + Page* cur_page = Page::FromAllocationTop(cur_addr_); cur_page = cur_page->next_page(); - if (cur_page == space_->anchor()) return false; + ASSERT(cur_page->is_valid()); + cur_addr_ = cur_page->ObjectAreaStart(); - cur_end_ = cur_page->ObjectAreaEnd(); - ASSERT(cur_page->WasSweptPrecisely()); - return true; + 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(); } #ifdef DEBUG void HeapObjectIterator::Verify() { - // TODO(gc): We should do something here. + Page* p = Page::FromAllocationTop(cur_addr_); + ASSERT(p == Page::FromAllocationTop(cur_limit_)); + ASSERT(p->Offset(cur_addr_) <= p->Offset(cur_limit_)); } #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 @@ -157,12 +171,7 @@ 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)); - 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)); + allocation_list_.Add(FreeBlock(code_range_->address(), code_range_->size())); current_allocation_block_index_ = 0; return true; } @@ -219,8 +228,7 @@ void CodeRange::GetNextAllocationBlock(size_t requested) { -Address CodeRange::AllocateRawMemory(const size_t requested, - size_t* allocated) { +void* 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 @@ -228,16 +236,13 @@ Address CodeRange::AllocateRawMemory(const size_t requested, GetNextAllocationBlock(requested); } // Commit the requested memory at the start of the current allocation block. - size_t aligned_requested = RoundUp(requested, MemoryChunk::kAlignment); + *allocated = RoundUp(requested, Page::kPageSize); FreeBlock current = allocation_list_[current_allocation_block_index_]; - if (aligned_requested >= (current.size - Page::kPageSize)) { + if (*allocated >= 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; @@ -251,8 +256,7 @@ Address CodeRange::AllocateRawMemory(const size_t requested, } -void CodeRange::FreeRawMemory(Address address, size_t length) { - ASSERT(IsAddressAligned(address, MemoryChunk::kAlignment)); +void CodeRange::FreeRawMemory(void* address, size_t length) { free_list_.Add(FreeBlock(address, length)); code_range_->Uncommit(address, length); } @@ -270,12 +274,35 @@ 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) { + 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_]; } @@ -284,303 +311,269 @@ 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() { - // 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); + 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; capacity_ = 0; capacity_executable_ = 0; + size_ = 0; + max_nof_chunks_ = 0; } -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)); - - if (executable == EXECUTABLE) { - ASSERT(size_executable_ >= size); - size_executable_ -= size; +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; } - // 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::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)); + void* mem; 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); + // 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 { - ASSERT(executable == NOT_EXECUTABLE || !isolate_->code_range()->exists()); - bool result = VirtualMemory::ReleaseRegion(base, size); - USE(result); - ASSERT(result); + mem = OS::Allocate(requested, allocated, false); } + 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; } -Address MemoryAllocator::ReserveAlignedMemory(size_t size, - size_t alignment, - VirtualMemory* controller) { - VirtualMemory reservation(size, alignment); +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); + } else { + OS::Free(mem, length); + } + isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(length)); + size_ -= static_cast<int>(length); + if (executable == EXECUTABLE) size_executable_ -= static_cast<int>(length); - if (!reservation.IsReserved()) return NULL; - size_ += reservation.size(); - Address base = RoundUp(static_cast<Address>(reservation.address()), - alignment); - controller->TakeControl(&reservation); - return base; + ASSERT(size_ >= 0); + ASSERT(size_executable_ >= 0); } -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; +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)); } - controller->TakeControl(&reservation); - return base; } -void Page::InitializeAsAnchor(PagedSpace* owner) { - set_owner(owner); - set_prev_page(this); - set_next_page(this); +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; } -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::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 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::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* MemoryAllocator::ReserveInitialChunk(const size_t requested) { + ASSERT(initial_chunk_ == NULL); -MemoryChunk* MemoryChunk::Initialize(Heap* heap, - Address base, - size_t size, - Executability executable, - Space* owner) { - MemoryChunk* chunk = FromAddress(base); - - 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); - - if (executable == EXECUTABLE) chunk->SetFlag(IS_EXECUTABLE); - - if (owner == heap->old_data_space()) chunk->SetFlag(CONTAINS_ONLY_DATA); + initial_chunk_ = new VirtualMemory(requested); + CHECK(initial_chunk_ != NULL); + if (!initial_chunk_->IsReserved()) { + delete initial_chunk_; + initial_chunk_ = NULL; + return NULL; + } - return chunk; + // 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(); } -void MemoryChunk::InsertAfter(MemoryChunk* other) { - next_chunk_ = other->next_chunk_; - prev_chunk_ = other; - other->next_chunk_->prev_chunk_ = this; - other->next_chunk_ = this; +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); } -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; -} +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* chunk = AllocateRawMemory(chunk_size, &chunk_size, owner->executable()); + if (chunk == NULL) return Page::FromAddress(NULL); + LOG(isolate_, NewEvent("PagedChunk", chunk, chunk_size)); -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; - } + *allocated_pages = PagesInChunk(static_cast<Address>(chunk), chunk_size); - // 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); + // We may 'lose' a page due to alignment. + ASSERT(*allocated_pages >= kPagesPerChunk - 1); - if (base == NULL) return NULL; - } - -#ifdef DEBUG - ZapBlock(base, chunk_size); -#endif - isolate_->counters()->memory_allocated()-> - Increment(static_cast<int>(chunk_size)); + size_t guard_size = (owner->executable() == EXECUTABLE) ? Page::kPageSize : 0; - LOG(isolate_, NewEvent("MemoryChunk", base, chunk_size)); - if (owner != NULL) { - ObjectSpace space = static_cast<ObjectSpace>(1 << owner->identity()); - PerformAllocationCallback(space, kAllocationActionAllocate, chunk_size); + // 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); } - MemoryChunk* result = MemoryChunk::Initialize(heap, - base, - chunk_size, - executable, - owner); - result->set_reserved_memory(&reservation); - return result; -} - - -Page* MemoryAllocator::AllocatePage(PagedSpace* owner, - Executability executable) { - MemoryChunk* chunk = AllocateChunk(Page::kObjectAreaSize, executable, owner); - - if (chunk == 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; + } - return Page::Initialize(isolate_->heap(), chunk, executable, owner); -} + int chunk_id = Pop(); + chunks_[chunk_id].init(static_cast<Address>(chunk), chunk_size, owner); + ObjectSpace space = static_cast<ObjectSpace>(1 << owner->identity()); + PerformAllocationCallback(space, kAllocationActionAllocate, chunk_size); + Page* new_pages = InitializePagesInChunk(chunk_id, *allocated_pages, owner); -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); + return new_pages; } -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()); +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); } +#ifdef DEBUG + ZapBlock(start, size); +#endif + isolate_->counters()->memory_allocated()->Increment(static_cast<int>(size)); - 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()); - } + // 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); } bool MemoryAllocator::CommitBlock(Address start, size_t size, Executability executable) { - if (!VirtualMemory::CommitRegion(start, size, executable)) return false; + 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; #ifdef DEBUG ZapBlock(start, size); #endif @@ -590,7 +583,13 @@ bool MemoryAllocator::CommitBlock(Address start, bool MemoryAllocator::UncommitBlock(Address start, size_t size) { - if (!VirtualMemory::UncommitRegion(start, size)) return false; + 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; isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size)); return true; } @@ -603,49 +602,130 @@ void MemoryAllocator::ZapBlock(Address start, size_t size) { } -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)); +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; } + + // 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); } -bool MemoryAllocator::MemoryAllocationCallbackRegistered( - MemoryAllocationCallback callback) { - for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { - if (memory_allocation_callbacks_[i].callback == callback) return true; +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 } - return false; -} + while (first_page->is_valid()) { + int chunk_id = GetChunkId(first_page); + ASSERT(IsValidChunk(chunk_id)); -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); + // 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); + } + + return page_to_return; } -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; +void MemoryAllocator::FreeAllPages(PagedSpace* space) { + for (int i = 0, length = chunks_.length(); i < length; i++) { + if (chunks_[i].owner() == space) { + DeleteChunk(i); } } - UNREACHABLE(); +} + + +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); + } + 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); } @@ -659,6 +739,75 @@ 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 @@ -666,11 +815,7 @@ PagedSpace::PagedSpace(Heap* heap, intptr_t max_capacity, AllocationSpace id, Executability executable) - : Space(heap, id, executable), - free_list_(this), - was_swept_conservatively_(false), - first_unswept_page_(Page::FromAddress(NULL)), - last_unswept_page_(Page::FromAddress(NULL)) { + : Space(heap, id, executable) { max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize) * Page::kObjectAreaSize; accounting_stats_.Clear(); @@ -678,73 +823,215 @@ PagedSpace::PagedSpace(Heap* heap, allocation_info_.top = NULL; allocation_info_.limit = NULL; - anchor_.InitializeAsAnchor(this); + mc_forwarding_info_.top = NULL; + mc_forwarding_info_.limit = NULL; } -bool PagedSpace::Setup() { +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; + return true; } bool PagedSpace::HasBeenSetup() { - return true; + return (Capacity() > 0); } void PagedSpace::TearDown() { - PageIterator iterator(this); - while (iterator.has_next()) { - heap()->isolate()->memory_allocator()->Free(iterator.next()); - } - anchor_.set_next_page(&anchor_); - anchor_.set_prev_page(&anchor_); + 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); + } +} + + MaybeObject* PagedSpace::FindObject(Address addr) { - // Note: this function can only be called on precisely swept spaces. + // Note: this function can only be called before or after mark-compact GC + // because it accesses map pointers. ASSERT(!heap()->mark_compact_collector()->in_use()); if (!Contains(addr)) return Failure::Exception(); Page* p = Page::FromAddress(addr); - HeapObjectIterator it(p, NULL); - for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) { - Address cur = obj->address(); + ASSERT(IsUsed(p)); + Address cur = p->ObjectAreaStart(); + Address end = p->AllocationTop(); + while (cur < end) { + HeapObject* obj = HeapObject::FromAddress(cur); 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); - if (Capacity() == max_capacity_) return false; +bool PagedSpace::IsUsed(Page* page) { + PageIterator it(this, PageIterator::PAGES_IN_USE); + while (it.has_next()) { + if (page == it.next()) return true; + } + return false; +} - ASSERT(Capacity() < max_capacity_); - // Are we going to exceed capacity for this space? - if ((Capacity() + Page::kPageSize) > max_capacity_) return false; +void PagedSpace::SetAllocationInfo(AllocationInfo* alloc_info, Page* p) { + alloc_info->top = p->ObjectAreaStart(); + alloc_info->limit = p->ObjectAreaEnd(); + ASSERT(alloc_info->VerifyPagedAllocation()); +} - return true; + +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(); } -bool PagedSpace::Expand() { - if (!CanExpand()) return false; - Page* p = heap()->isolate()->memory_allocator()-> - AllocatePage(this, executable()); - if (p == NULL) return false; +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); +} + + +// 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; + } + } + + // 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); +} + + +bool PagedSpace::Expand(Page* last_page) { + ASSERT(max_capacity_ % Page::kObjectAreaSize == 0); + ASSERT(Capacity() % Page::kObjectAreaSize == 0); + + if (Capacity() == max_capacity_) 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_); - p->InsertAfter(anchor_.prev_page()); + 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(); + } return true; } @@ -752,10 +1039,8 @@ bool PagedSpace::Expand() { #ifdef DEBUG int PagedSpace::CountTotalPages() { - PageIterator it(this); int count = 0; - while (it.has_next()) { - it.next(); + for (Page* p = first_page_; p->is_valid(); p = p->next_page()) { count++; } return count; @@ -763,30 +1048,63 @@ int PagedSpace::CountTotalPages() { #endif -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); +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; } - ASSERT(Capacity() > 0); - ASSERT(Capacity() % Page::kObjectAreaSize == 0); - accounting_stats_.ShrinkSpace(Page::kObjectAreaSize); + // 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; + } + + accounting_stats_.ShrinkSpace(pages_to_free * Page::kObjectAreaSize); + ASSERT(Capacity() == CountTotalPages() * Page::kObjectAreaSize); } -void PagedSpace::ReleaseAllUnusedPages() { - PageIterator it(this); - while (it.has_next()) { - Page* page = it.next(); - if (page->LiveBytes() == 0) { - ReleasePage(page); - } +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(); } - heap()->FreeQueuedChunks(); + + // 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; } @@ -796,52 +1114,61 @@ 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) { - // 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 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; } - ASSERT(object->address() + size <= top); - end_of_previous_object = object->address() + size; + // 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; + } + + // The allocation pointer should not be in the middle of an object. + ASSERT(current == top); } - ASSERT_LE(black_size, page->LiveBytes()); + + current_page = current_page->next_page(); } - ASSERT(allocation_pointer_found_in_space); } #endif @@ -850,23 +1177,13 @@ void PagedSpace::Verify(ObjectVisitor* visitor) { // NewSpace implementation -bool NewSpace::Setup(int reserved_semispace_capacity, - int maximum_semispace_capacity) { +bool NewSpace::Setup(Address start, int size) { // 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(); - - 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_)); + int maximum_semispace_capacity = heap()->MaxSemiSpaceSize(); ASSERT(initial_semispace_capacity <= maximum_semispace_capacity); ASSERT(IsPowerOf2(maximum_semispace_capacity)); @@ -880,29 +1197,31 @@ bool NewSpace::Setup(int reserved_semispace_capacity, INSTANCE_TYPE_LIST(SET_NAME) #undef SET_NAME - 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)); + ASSERT(size == 2 * heap()->ReservedSemiSpaceSize()); + ASSERT(IsAddressAligned(start, size, 0)); - if (!to_space_.Setup(chunk_base_, + if (!to_space_.Setup(start, initial_semispace_capacity, maximum_semispace_capacity)) { return false; } - if (!from_space_.Setup(chunk_base_ + reserved_semispace_capacity, + if (!from_space_.Setup(start + maximum_semispace_capacity, initial_semispace_capacity, maximum_semispace_capacity)) { return false; } - start_ = chunk_base_; - address_mask_ = ~(2 * reserved_semispace_capacity - 1); + start_ = start; + address_mask_ = ~(size - 1); object_mask_ = address_mask_ | kHeapObjectTagMask; - object_expected_ = reinterpret_cast<uintptr_t>(start_) | kHeapObjectTag; + object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag; - ResetAllocationInfo(); + allocation_info_.top = to_space_.low(); + allocation_info_.limit = to_space_.high(); + mc_forwarding_info_.top = NULL; + mc_forwarding_info_.limit = NULL; + ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); return true; } @@ -920,34 +1239,28 @@ 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::Swap(&from_space_, &to_space_); + SemiSpace tmp = from_space_; + from_space_ = to_space_; + to_space_ = tmp; } void NewSpace::Grow() { - // Double the semispace size but only up to maximum capacity. ASSERT(Capacity() < MaximumCapacity()); - 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_.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. if (!to_space_.ShrinkTo(from_space_.Capacity())) { // We are in an inconsistent state because we could not // commit/uncommit memory from new space. @@ -955,20 +1268,21 @@ 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, Page::kPageSize); + int rounded_new_capacity = + RoundUp(new_capacity, static_cast<int>(OS::AllocateAlignment())); if (rounded_new_capacity < Capacity() && to_space_.ShrinkTo(rounded_new_capacity)) { - // Only shrink from-space if we managed to shrink to-space. - from_space_.Reset(); + // Only shrink from space if we managed to shrink to space. 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. @@ -976,65 +1290,36 @@ void NewSpace::Shrink() { } } } - allocation_info_.limit = to_space_.page_high(); + allocation_info_.limit = to_space_.high(); ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); } -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); - } +void NewSpace::ResetAllocationInfo() { + allocation_info_.top = to_space_.low(); + allocation_info_.limit = to_space_.high(); ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_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::MCResetRelocationInfo() { + mc_forwarding_info_.top = from_space_.low(); + mc_forwarding_info_.limit = from_space_.high(); + ASSERT_SEMISPACE_ALLOCATION_INFO(mc_forwarding_info_, from_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; +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_); } #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. @@ -1042,52 +1327,58 @@ void NewSpace::Verify() { // There should be objects packed in from the low address up to the // allocation pointer. - Address current = to_space_.first_page()->body(); - CHECK_EQ(current, to_space_.space_start()); + Address current = to_space_.low(); + while (current < top()) { + HeapObject* object = HeapObject::FromAddress(current); - 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 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)); - HeapObject* object = HeapObject::FromAddress(current); + // The object should not be code or a map. + ASSERT(!object->IsMap()); + ASSERT(!object->IsCode()); + + // The object itself should look OK. + object->Verify(); - // 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)); + // All the interior pointers should be contained in the heap. + VerifyPointersVisitor visitor; + int size = object->Size(); + object->IterateBody(map->instance_type(), size, &visitor); - // The object should not be code or a map. - CHECK(!object->IsMap()); - CHECK(!object->IsCode()); + current += size; + } - // The object itself should look OK. - object->Verify(); + // The allocation pointer should not be in the middle of an object. + ASSERT(current == top()); +} +#endif - // All the interior pointers should be contained in the heap. - VerifyPointersVisitor visitor; - int size = object->Size(); - object->IterateBody(map->instance_type(), size, &visitor); - 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(); - } +bool SemiSpace::Commit() { + ASSERT(!is_committed()); + if (!heap()->isolate()->memory_allocator()->CommitBlock( + start_, capacity_, executable())) { + return false; } + committed_ = true; + return true; +} - // Check semi-spaces. - ASSERT_EQ(from_space_.id(), kFromSpace); - ASSERT_EQ(to_space_.id(), kToSpace); - from_space_.Verify(); - to_space_.Verify(); + +bool SemiSpace::Uncommit() { + ASSERT(is_committed()); + if (!heap()->isolate()->memory_allocator()->UncommitBlock( + start_, capacity_)) { + return false; + } + committed_ = false; + return true; } -#endif + // ----------------------------------------------------------------------------- // SemiSpace implementation @@ -1101,11 +1392,11 @@ 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. - ASSERT(maximum_capacity >= Page::kPageSize); - initial_capacity_ = RoundDown(initial_capacity, Page::kPageSize); + initial_capacity_ = initial_capacity; capacity_ = initial_capacity; - maximum_capacity_ = RoundDown(maximum_capacity, Page::kPageSize); + maximum_capacity_ = maximum_capacity; committed_ = false; + start_ = start; address_mask_ = ~(maximum_capacity - 1); object_mask_ = address_mask_ | kHeapObjectTagMask; @@ -1122,258 +1413,81 @@ void SemiSpace::TearDown() { } -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())) { +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())) { return false; } - - 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; + capacity_ += extra; 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( - start, delta, executable())) { + high(), 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(old_start, delta)) { + if (!heap()->isolate()->memory_allocator()->UncommitBlock( + high() - delta, 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() { - 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()); - } - } -} +void SemiSpace::Verify() { } #endif // ----------------------------------------------------------------------------- // SemiSpaceIterator implementation. SemiSpaceIterator::SemiSpaceIterator(NewSpace* space) { - Initialize(space->bottom(), space->top(), NULL); + Initialize(space, space->bottom(), space->top(), NULL); } SemiSpaceIterator::SemiSpaceIterator(NewSpace* space, HeapObjectCallback size_func) { - Initialize(space->bottom(), space->top(), size_func); + Initialize(space, space->bottom(), space->top(), size_func); } SemiSpaceIterator::SemiSpaceIterator(NewSpace* space, Address start) { - Initialize(start, space->top(), NULL); -} - - -SemiSpaceIterator::SemiSpaceIterator(Address from, Address to) { - Initialize(from, to, NULL); + Initialize(space, start, space->top(), NULL); } -void SemiSpaceIterator::Initialize(Address start, +void SemiSpaceIterator::Initialize(NewSpace* space, Address start, Address end, HeapObjectCallback size_func) { - SemiSpace::AssertValidRange(start, end); + ASSERT(space->ToSpaceContains(start)); + ASSERT(space->ToSpaceLow() <= end + && end <= space->ToSpaceHigh()); + space_ = &space->to_space_; current_ = start; limit_ = end; size_func_ = size_func; @@ -1509,7 +1623,7 @@ 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); } @@ -1585,6 +1699,7 @@ void NewSpace::RecordPromotion(HeapObject* obj) { promoted_histogram_[type].increment_bytes(obj->Size()); } + // ----------------------------------------------------------------------------- // Free lists for old object spaces implementation @@ -1593,17 +1708,17 @@ 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 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 + // 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 // 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 > 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); + 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)); } else if (size_in_bytes == kPointerSize) { set_map(heap->raw_unchecked_one_pointer_filler_map()); } else if (size_in_bytes == 2 * kPointerSize) { @@ -1612,295 +1727,318 @@ 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 free space map is not done yet. + // deserialization because the byte array map is not done yet. } -FreeListNode* FreeListNode::next() { +Address FreeListNode::next(Heap* heap) { ASSERT(IsFreeListNode(this)); - if (map() == HEAP->raw_unchecked_free_space_map()) { - ASSERT(map() == NULL || Size() >= kNextOffset + kPointerSize); - return reinterpret_cast<FreeListNode*>( - Memory::Address_at(address() + kNextOffset)); + if (map() == heap->raw_unchecked_byte_array_map()) { + ASSERT(Size() >= kNextOffset + kPointerSize); + return Memory::Address_at(address() + kNextOffset); } else { - return reinterpret_cast<FreeListNode*>( - Memory::Address_at(address() + kPointerSize)); + return Memory::Address_at(address() + kPointerSize); } } -FreeListNode** FreeListNode::next_address() { +void FreeListNode::set_next(Heap* heap, Address next) { ASSERT(IsFreeListNode(this)); - if (map() == HEAP->raw_unchecked_free_space_map()) { + if (map() == heap->raw_unchecked_byte_array_map()) { ASSERT(Size() >= kNextOffset + kPointerSize); - return reinterpret_cast<FreeListNode**>(address() + kNextOffset); + Memory::Address_at(address() + kNextOffset) = next; } else { - return reinterpret_cast<FreeListNode**>(address() + kPointerSize); + Memory::Address_at(address() + kPointerSize) = next; } } -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); - } +OldSpaceFreeList::OldSpaceFreeList(Heap* heap, AllocationSpace owner) + : heap_(heap), + owner_(owner) { + Reset(); } -FreeList::FreeList(PagedSpace* owner) - : owner_(owner), heap_(owner->heap()) { - Reset(); +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; } -void FreeList::Reset() { - available_ = 0; - small_list_ = NULL; - medium_list_ = NULL; - large_list_ = NULL; - huge_list_ = NULL; +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; } -int FreeList::Free(Address start, int size_in_bytes) { - if (size_in_bytes == 0) return 0; +int OldSpaceFreeList::Free(Address start, int size_in_bytes) { +#ifdef DEBUG + Isolate::Current()->memory_allocator()->ZapBlock(start, size_in_bytes); +#endif FreeListNode* node = FreeListNode::FromAddress(start); node->set_size(heap_, 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; + // 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; + } + + // 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; - ASSERT(IsVeryLong() || available_ == SumFreeLists()); + needs_rebuild_ = true; return 0; } -FreeListNode* FreeList::PickNodeFromList(FreeListNode** list, int* node_size) { - FreeListNode* node = *list; - - if (node == NULL) return NULL; - - while (node != NULL && - Page::FromAddress(node->address())->IsEvacuationCandidate()) { - available_ -= node->Size(); - node = node->next(); - } +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)); - if (node != NULL) { - *node_size = node->Size(); - *list = node->next(); + 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(); } else { - *list = NULL; + // 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); } - - return node; + available_ -= size_in_bytes; + *wasted_bytes = 0; + return cur_node; } -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; +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(); + } } +} - if (size_in_bytes <= kMediumAllocationMax) { - node = PickNodeFromList(&medium_list_, node_size); - if (node != NULL) return node; - } - if (size_in_bytes <= kLargeAllocationMax) { - node = PickNodeFromList(&large_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_); + } } + return false; +} +#endif - 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; - } - } +FixedSizeFreeList::FixedSizeFreeList(Heap* heap, + AllocationSpace owner, + int object_size) + : heap_(heap), owner_(owner), object_size_(object_size) { + Reset(); +} - return node; + +void FixedSizeFreeList::Reset() { + available_ = 0; + head_ = tail_ = NULL; } -// 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); - - 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); +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(); } else { - // TODO(gc) Try not freeing linear allocation region when bytes_left - // are zero. - owner_->SetTop(NULL, NULL); + FreeListNode::FromAddress(tail_)->set_next(heap_, node->address()); + tail_ = node->address(); } - - return new_node; + available_ += object_size_; } -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(); +MaybeObject* FixedSizeFreeList::Allocate() { + if (head_ == NULL) { + return Failure::RetryAfterGC(owner_); } - return sum; -} - -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); + 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; } -#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(); + +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(); } - return sum; } -static const int kVeryLongFreeList = 500; - +// ----------------------------------------------------------------------------- +// OldSpace implementation -int FreeList::FreeListLength(FreeListNode* cur) { - int length = 0; - while (cur != NULL) { - length++; - cur = cur->next(); - if (length == kVeryLongFreeList) return length; +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()); } - return length; + + // Clear the free list before a full GC---it will be rebuilt afterward. + free_list_.Reset(); } -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; -} +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()); + // The space is compacted and we haven't yet built free lists or + // wasted any space. + ASSERT(Waste() == 0); + ASSERT(AvailableFree() == 0); -// 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 + // 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()); +} -// ----------------------------------------------------------------------------- -// OldSpace implementation bool NewSpace::ReserveSpace(int bytes) { // We can't reliably unpack a partial snapshot that needs more new space @@ -1912,119 +2050,200 @@ bool NewSpace::ReserveSpace(int bytes) { } -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); +void PagedSpace::FreePages(Page* prev, Page* last) { + if (last == AllocationTopPage()) { + // Pages are already at the end of used pages. + return; } - first_unswept_page_ = last_unswept_page_ = Page::FromAddress(NULL); - // Clear the free list before a full GC---it will be rebuilt afterward. - free_list_.Reset(); -} + 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()); + } + // Attach it after the last page. + heap()->isolate()->memory_allocator()->SetNextPage(last_page_, first); + last_page_ = last; + heap()->isolate()->memory_allocator()->SetNextPage(last, NULL); -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; + // 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; + } + } - 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; + if (page_list_is_chunk_ordered_) return; - 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); + 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()); - SetTop(new_area->address(), new_area->address() + size_in_bytes); - Allocate(size_in_bytes); - return true; -} + 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()); + 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); + } + } -// 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; -} + // New last in use page was in the middle of the list before + // sorting so it full. + SetTop(new_last_in_use->AllocationTop()); + ASSERT(AllocationTopPage() == new_last_in_use); + ASSERT(AllocationTopPage()->WasInUseBeforeMC()); + } -bool PagedSpace::AdvanceSweeper(intptr_t bytes_to_sweep) { - if (IsSweepingComplete()) return true; + 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()); - 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)); + 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); } - 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; } - heap()->LowerOldGenLimits(freed_bytes); + page_list_is_chunk_ordered_ = true; +} - heap()->FreeQueuedChunks(); - return IsSweepingComplete(); +void PagedSpace::PrepareForMarkCompact(bool will_compact) { + if (will_compact) { + RelinkPageListInChunkOrder(false); + } } -void PagedSpace::EvictEvacuationCandidatesFromFreeLists() { - if (allocation_info_.top >= allocation_info_.limit) return; +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; +} - 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); - allocation_info_.top = NULL; - allocation_info_.limit = NULL; - } +// 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; } -HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) { - // Allocation in this space has failed. +// 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; + } + } // 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 @@ -2034,30 +2253,61 @@ HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) { return NULL; } - // If there are unswept pages advance lazy sweeper. - if (first_unswept_page_->is_valid()) { - AdvanceSweeper(size_in_bytes); + // 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); + } - // Retry the free list allocation. - HeapObject* object = free_list_.Allocate(size_in_bytes); - if (object != NULL) return object; + // Finally, fail. + return NULL; +} - if (!IsSweepingComplete()) { - AdvanceSweeper(kMaxInt); - // Retry the free list allocation. - object = free_list_.Allocate(size_in_bytes); - if (object != NULL) return object; - } +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); } +} - // Try to expand the space and allocate in the new next page. - if (Expand()) { - return free_list_.Allocate(size_in_bytes); + +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_); } +} - // Finally, fail. - return NULL; + +// 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); } @@ -2163,7 +2413,7 @@ 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(); @@ -2188,17 +2438,16 @@ void PagedSpace::CollectCodeStatistics() { } -void PagedSpace::ReportStatistics() { +void OldSpace::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); } @@ -2207,28 +2456,192 @@ void PagedSpace::ReportStatistics() { // ----------------------------------------------------------------------------- // FixedSpace implementation -void FixedSpace::PrepareForMarkCompact() { +void FixedSpace::PrepareForMarkCompact(bool will_compact) { // Call prepare of the super class. - PagedSpace::PrepareForMarkCompact(); + PagedSpace::PrepareForMarkCompact(will_compact); - // 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()); + if (will_compact) { + // Reset relocation info. + MCResetRelocationInfo(); + + // 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()); + } // 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->IsFreeSpace()); + ASSERT(object->IsMap() || object->IsByteArray()); } #endif @@ -2249,40 +2662,107 @@ void CellSpace::VerifyObject(HeapObject* object) { // LargeObjectIterator LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space) { - current_ = space->first_page_; + current_ = space->first_chunk_; size_func_ = NULL; } LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space, HeapObjectCallback size_func) { - current_ = space->first_page_; + current_ = space->first_chunk_; size_func_ = size_func; } -HeapObject* LargeObjectIterator::Next() { +HeapObject* LargeObjectIterator::next() { if (current_ == NULL) return NULL; HeapObject* object = current_->GetObject(); - current_ = current_->next_page(); + current_ = current_->next(); 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_page_(NULL), + first_chunk_(NULL), size_(0), page_count_(0), objects_size_(0) {} bool LargeObjectSpace::Setup() { - first_page_ = NULL; + first_chunk_ = NULL; size_ = 0; page_count_ = 0; objects_size_ = 0; @@ -2291,22 +2771,20 @@ bool LargeObjectSpace::Setup() { void LargeObjectSpace::TearDown() { - 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); + while (first_chunk_ != NULL) { + LargeObjectChunk* chunk = first_chunk_; + first_chunk_ = first_chunk_->next(); + chunk->Free(chunk->GetPage()->PageExecutability()); } Setup(); } -MaybeObject* LargeObjectSpace::AllocateRaw(int object_size, - Executability executable) { +MaybeObject* LargeObjectSpace::AllocateRawInternal(int requested_size, + int object_size, + Executability executable) { + ASSERT(0 < object_size && object_size <= requested_size); + // Check if we want to force a GC before growing the old space further. // If so, fail the allocation. if (!heap()->always_allocate() && @@ -2314,42 +2792,75 @@ MaybeObject* LargeObjectSpace::AllocateRaw(int object_size, 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); + LargeObjectChunk* chunk = LargeObjectChunk::New(requested_size, executable); + if (chunk == NULL) { + return Failure::RetryAfterGC(identity()); + } - size_ += static_cast<int>(page->size()); - objects_size_ += object_size; + size_ += static_cast<int>(chunk->size()); + objects_size_ += requested_size; page_count_++; - page->set_next_page(first_page_); - first_page_ = page; + 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); +} + - heap()->incremental_marking()->OldSpaceStep(object_size); - return page->GetObject(); +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); } // GC support MaybeObject* LargeObjectSpace::FindObject(Address a) { - 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(); + 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(); } } return Failure::Exception(); } -LargePage* LargeObjectSpace::FindPageContainingPc(Address pc) { +LargeObjectChunk* LargeObjectSpace::FindChunkContainingPc(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 (LargePage* chunk = first_page_; + for (LargeObjectChunk* chunk = first_chunk_; chunk != NULL; - chunk = chunk->next_page()) { + chunk = chunk->next()) { Address chunk_address = chunk->address(); if (chunk_address <= pc && pc < chunk_address + chunk->size()) { return chunk; @@ -2359,57 +2870,112 @@ LargePage* LargeObjectSpace::FindPageContainingPc(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() { - LargePage* previous = NULL; - LargePage* current = first_page_; + LargeObjectChunk* previous = NULL; + LargeObjectChunk* current = first_chunk_; while (current != NULL) { HeapObject* object = current->GetObject(); - // 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()); + if (object->IsMarked()) { + object->ClearMark(); + heap()->mark_compact_collector()->tracer()->decrement_marked_count(); previous = current; - current = current->next_page(); + current = current->next(); } else { - LargePage* page = current; // Cut the chunk out from the chunk list. - current = current->next_page(); + LargeObjectChunk* current_chunk = current; + current = current->next(); if (previous == NULL) { - first_page_ = current; + first_chunk_ = current; } else { - previous->set_next_page(current); + previous->set_next(current); } // Free the chunk. heap()->mark_compact_collector()->ReportDeleteIfNeeded( object, heap()->isolate()); - size_ -= static_cast<int>(page->size()); + LiveObjectList::ProcessNonLive(object); + + size_ -= static_cast<int>(current_chunk->size()); objects_size_ -= object->Size(); page_count_--; - - if (is_pointer_object) { - heap()->QueueMemoryChunkForFree(page); - } else { - heap()->isolate()->memory_allocator()->Free(page); - } + current_chunk->Free(current_chunk->GetPage()->PageExecutability()); } } - heap()->FreeQueuedChunks(); } bool LargeObjectSpace::Contains(HeapObject* object) { Address address = object->address(); - MemoryChunk* chunk = MemoryChunk::FromAddress(address); - - bool owned = (chunk->owner() == this); + if (heap()->new_space()->Contains(address)) { + return false; + } + Page* page = Page::FromAddress(address); - SLOW_ASSERT(!owned || !FindObject(address)->IsFailure()); + SLOW_ASSERT(!page->IsLargeObjectPage() + || !FindObject(address)->IsFailure()); - return owned; + return page->IsLargeObjectPage(); } @@ -2417,9 +2983,9 @@ 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 (LargePage* chunk = first_page_; + for (LargeObjectChunk* chunk = first_chunk_; chunk != NULL; - chunk = chunk->next_page()) { + chunk = chunk->next()) { // Each chunk contains an object that starts at the large object page's // object area start. HeapObject* object = chunk->GetObject(); @@ -2449,6 +3015,9 @@ 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); @@ -2456,6 +3025,13 @@ 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)); + } } } } @@ -2465,7 +3041,7 @@ 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(); } } @@ -2476,7 +3052,7 @@ 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); } @@ -2490,38 +3066,13 @@ 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 |