| // Copyright 2006-2008 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "v8.h" |
| |
| #include "macro-assembler.h" |
| #include "mark-compact.h" |
| #include "platform.h" |
| |
| namespace v8 { namespace internal { |
| |
| // For contiguous spaces, top should be in the space (or at the end) and limit |
| // should be the end of the space. |
| #define ASSERT_SEMISPACE_ALLOCATION_INFO(info, space) \ |
| ASSERT((space).low() <= (info).top \ |
| && (info).top <= (space).high() \ |
| && (info).limit == (space).high()) |
| |
| |
| // ---------------------------------------------------------------------------- |
| // HeapObjectIterator |
| |
| HeapObjectIterator::HeapObjectIterator(PagedSpace* space) { |
| Initialize(space->bottom(), space->top(), NULL); |
| } |
| |
| |
| HeapObjectIterator::HeapObjectIterator(PagedSpace* space, |
| HeapObjectCallback size_func) { |
| Initialize(space->bottom(), space->top(), size_func); |
| } |
| |
| |
| HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start) { |
| Initialize(start, space->top(), NULL); |
| } |
| |
| |
| HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start, |
| HeapObjectCallback size_func) { |
| Initialize(start, space->top(), size_func); |
| } |
| |
| |
| void HeapObjectIterator::Initialize(Address cur, Address end, |
| HeapObjectCallback size_f) { |
| cur_addr_ = cur; |
| 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(); |
| #endif |
| } |
| |
| |
| bool HeapObjectIterator::HasNextInNextPage() { |
| if (cur_addr_ == end_addr_) return false; |
| |
| Page* cur_page = Page::FromAllocationTop(cur_addr_); |
| cur_page = cur_page->next_page(); |
| ASSERT(cur_page->is_valid()); |
| |
| cur_addr_ = cur_page->ObjectAreaStart(); |
| cur_limit_ = (cur_page == end_page_) ? end_addr_ : cur_page->AllocationTop(); |
| |
| ASSERT(cur_addr_ < cur_limit_); |
| #ifdef DEBUG |
| Verify(); |
| #endif |
| return true; |
| } |
| |
| |
| #ifdef DEBUG |
| void HeapObjectIterator::Verify() { |
| Page* p = Page::FromAllocationTop(cur_addr_); |
| ASSERT(p == Page::FromAllocationTop(cur_limit_)); |
| ASSERT(p->Offset(cur_addr_) <= p->Offset(cur_limit_)); |
| } |
| #endif |
| |
| |
| // ----------------------------------------------------------------------------- |
| // PageIterator |
| |
| PageIterator::PageIterator(PagedSpace* space, Mode mode) { |
| cur_page_ = space->first_page_; |
| switch (mode) { |
| case PAGES_IN_USE: |
| stop_page_ = space->AllocationTopPage()->next_page(); |
| break; |
| case PAGES_USED_BY_MC: |
| stop_page_ = space->MCRelocationTopPage()->next_page(); |
| break; |
| case ALL_PAGES: |
| stop_page_ = Page::FromAddress(NULL); |
| break; |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| |
| // ----------------------------------------------------------------------------- |
| // Page |
| |
| #ifdef DEBUG |
| Page::RSetState Page::rset_state_ = Page::IN_USE; |
| #endif |
| |
| // ----------------------------------------------------------------------------- |
| // MemoryAllocator |
| // |
| int MemoryAllocator::capacity_ = 0; |
| int MemoryAllocator::size_ = 0; |
| |
| VirtualMemory* MemoryAllocator::initial_chunk_ = NULL; |
| |
| // 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; |
| List<MemoryAllocator::ChunkInfo> MemoryAllocator::chunks_( |
| kEstimatedNumberOfChunks); |
| List<int> MemoryAllocator::free_chunk_ids_(kEstimatedNumberOfChunks); |
| int MemoryAllocator::max_nof_chunks_ = 0; |
| int MemoryAllocator::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_]; |
| } |
| |
| |
| bool MemoryAllocator::Setup(int capacity) { |
| capacity_ = RoundUp(capacity, Page::kPageSize); |
| |
| // 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_ = (capacity_ / (kChunkSize - Page::kPageSize)) + 5; |
| if (max_nof_chunks_ > kMaxNofChunks) return false; |
| |
| size_ = 0; |
| ChunkInfo info; // uninitialized element. |
| for (int i = max_nof_chunks_ - 1; i >= 0; i--) { |
| chunks_.Add(info); |
| free_chunk_ids_.Add(i); |
| } |
| top_ = max_nof_chunks_; |
| return true; |
| } |
| |
| |
| void MemoryAllocator::TearDown() { |
| for (int i = 0; i < max_nof_chunks_; i++) { |
| if (chunks_[i].address() != NULL) DeleteChunk(i); |
| } |
| chunks_.Clear(); |
| free_chunk_ids_.Clear(); |
| |
| if (initial_chunk_ != NULL) { |
| LOG(DeleteEvent("InitialChunk", initial_chunk_->address())); |
| delete initial_chunk_; |
| initial_chunk_ = NULL; |
| } |
| |
| ASSERT(top_ == max_nof_chunks_); // all chunks are free |
| top_ = 0; |
| capacity_ = 0; |
| size_ = 0; |
| max_nof_chunks_ = 0; |
| } |
| |
| |
| void* MemoryAllocator::AllocateRawMemory(const size_t requested, |
| size_t* allocated, |
| Executability executable) { |
| if (size_ + static_cast<int>(requested) > capacity_) return NULL; |
| |
| void* mem = OS::Allocate(requested, allocated, executable == EXECUTABLE); |
| int alloced = *allocated; |
| size_ += alloced; |
| Counters::memory_allocated.Increment(alloced); |
| return mem; |
| } |
| |
| |
| void MemoryAllocator::FreeRawMemory(void* mem, size_t length) { |
| OS::Free(mem, length); |
| Counters::memory_allocated.Decrement(length); |
| size_ -= length; |
| ASSERT(size_ >= 0); |
| } |
| |
| |
| void* MemoryAllocator::ReserveInitialChunk(const size_t requested) { |
| ASSERT(initial_chunk_ == NULL); |
| |
| initial_chunk_ = new VirtualMemory(requested); |
| CHECK(initial_chunk_ != NULL); |
| if (!initial_chunk_->IsReserved()) { |
| delete initial_chunk_; |
| initial_chunk_ = NULL; |
| return NULL; |
| } |
| |
| // We are sure that we have mapped a block of requested addresses. |
| ASSERT(initial_chunk_->size() == requested); |
| LOG(NewEvent("InitialChunk", initial_chunk_->address(), requested)); |
| size_ += requested; |
| return initial_chunk_->address(); |
| } |
| |
| |
| 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 (RoundDown(start + size, Page::kPageSize) |
| - RoundUp(start, Page::kPageSize)) >> Page::kPageSizeBits; |
| } |
| |
| |
| 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; |
| |
| // There is not enough space to guarantee the desired number pages can be |
| // allocated. |
| if (size_ + static_cast<int>(chunk_size) > capacity_) { |
| // Request as many pages as we can. |
| chunk_size = capacity_ - size_; |
| requested_pages = chunk_size >> Page::kPageSizeBits; |
| |
| if (requested_pages <= 0) return Page::FromAddress(NULL); |
| } |
| void* chunk = AllocateRawMemory(chunk_size, &chunk_size, owner->executable()); |
| if (chunk == NULL) return Page::FromAddress(NULL); |
| LOG(NewEvent("PagedChunk", chunk, chunk_size)); |
| |
| *allocated_pages = PagesInChunk(static_cast<Address>(chunk), chunk_size); |
| if (*allocated_pages == 0) { |
| FreeRawMemory(chunk, chunk_size); |
| LOG(DeleteEvent("PagedChunk", chunk)); |
| return Page::FromAddress(NULL); |
| } |
| |
| int chunk_id = Pop(); |
| chunks_[chunk_id].init(static_cast<Address>(chunk), chunk_size, owner); |
| |
| return InitializePagesInChunk(chunk_id, *allocated_pages, owner); |
| } |
| |
| |
| Page* MemoryAllocator::CommitPages(Address start, size_t size, |
| PagedSpace* owner, int* num_pages) { |
| ASSERT(start != NULL); |
| *num_pages = PagesInChunk(start, size); |
| ASSERT(*num_pages > 0); |
| ASSERT(initial_chunk_ != NULL); |
| ASSERT(InInitialChunk(start)); |
| ASSERT(InInitialChunk(start + size - 1)); |
| if (!initial_chunk_->Commit(start, size, owner->executable() == EXECUTABLE)) { |
| return Page::FromAddress(NULL); |
| } |
| Counters::memory_allocated.Increment(size); |
| |
| // So long as we correctly overestimated the number of chunks we should not |
| // run out of chunk ids. |
| CHECK(!OutOfChunkIds()); |
| int chunk_id = Pop(); |
| chunks_[chunk_id].init(start, size, owner); |
| return InitializePagesInChunk(chunk_id, *num_pages, owner); |
| } |
| |
| |
| bool MemoryAllocator::CommitBlock(Address start, |
| size_t size, |
| Executability executable) { |
| ASSERT(start != NULL); |
| ASSERT(size > 0); |
| ASSERT(initial_chunk_ != NULL); |
| ASSERT(InInitialChunk(start)); |
| ASSERT(InInitialChunk(start + size - 1)); |
| |
| if (!initial_chunk_->Commit(start, size, executable)) return false; |
| Counters::memory_allocated.Increment(size); |
| return true; |
| } |
| |
| |
| 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->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id; |
| p->is_normal_page = 1; |
| 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); |
| } |
| |
| |
| Page* MemoryAllocator::FreePages(Page* p) { |
| if (!p->is_valid()) return p; |
| |
| // Find the first page in the same chunk as 'p' |
| Page* first_page = FindFirstPageInSameChunk(p); |
| Page* page_to_return = Page::FromAddress(NULL); |
| |
| if (p != first_page) { |
| // Find the last page in the same chunk as 'prev'. |
| Page* last_page = FindLastPageInSameChunk(p); |
| first_page = GetNextPage(last_page); // first page in next chunk |
| |
| // set the next_page of last_page to NULL |
| SetNextPage(last_page, Page::FromAddress(NULL)); |
| page_to_return = p; // return 'p' when exiting |
| } |
| |
| while (first_page->is_valid()) { |
| int chunk_id = GetChunkId(first_page); |
| ASSERT(IsValidChunk(chunk_id)); |
| |
| // Find the first page of the next chunk before deleting this chunk. |
| first_page = GetNextPage(FindLastPageInSameChunk(first_page)); |
| |
| // Free the current chunk. |
| DeleteChunk(chunk_id); |
| } |
| |
| return page_to_return; |
| } |
| |
| |
| 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::memory_allocated.Decrement(c.size()); |
| } else { |
| LOG(DeleteEvent("PagedChunk", c.address())); |
| FreeRawMemory(c.address(), c.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); |
| } |
| |
| |
| #ifdef DEBUG |
| void MemoryAllocator::ReportStatistics() { |
| float pct = static_cast<float>(capacity_ - size_) / capacity_; |
| PrintF(" capacity: %d, used: %d, available: %%%d\n\n", |
| capacity_, size_, static_cast<int>(pct*100)); |
| } |
| #endif |
| |
| |
| // ----------------------------------------------------------------------------- |
| // PagedSpace implementation |
| |
| PagedSpace::PagedSpace(int max_capacity, |
| AllocationSpace id, |
| Executability executable) |
| : Space(id, executable) { |
| max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize) |
| * Page::kObjectAreaSize; |
| accounting_stats_.Clear(); |
| |
| allocation_info_.top = NULL; |
| allocation_info_.limit = NULL; |
| |
| mc_forwarding_info_.top = NULL; |
| mc_forwarding_info_.limit = NULL; |
| } |
| |
| |
| 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_ = MemoryAllocator::CommitPages(RoundUp(start, Page::kPageSize), |
| Page::kPageSize * pages_in_chunk, |
| this, &num_pages); |
| } else { |
| int requested_pages = Min(MemoryAllocator::kPagesPerChunk, |
| max_capacity_ / Page::kObjectAreaSize); |
| first_page_ = |
| MemoryAllocator::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_); |
| |
| for (Page* p = first_page_; p->is_valid(); p = p->next_page()) { |
| p->ClearRSet(); |
| } |
| |
| // Use first_page_ for allocation. |
| SetAllocationInfo(&allocation_info_, first_page_); |
| |
| return true; |
| } |
| |
| |
| bool PagedSpace::HasBeenSetup() { |
| return (Capacity() > 0); |
| } |
| |
| |
| void PagedSpace::TearDown() { |
| first_page_ = MemoryAllocator::FreePages(first_page_); |
| ASSERT(!first_page_->is_valid()); |
| |
| accounting_stats_.Clear(); |
| } |
| |
| |
| #ifdef ENABLE_HEAP_PROTECTION |
| |
| void PagedSpace::Protect() { |
| Page* page = first_page_; |
| while (page->is_valid()) { |
| MemoryAllocator::ProtectChunkFromPage(page); |
| page = MemoryAllocator::FindLastPageInSameChunk(page)->next_page(); |
| } |
| } |
| |
| |
| void PagedSpace::Unprotect() { |
| Page* page = first_page_; |
| while (page->is_valid()) { |
| MemoryAllocator::UnprotectChunkFromPage(page); |
| page = MemoryAllocator::FindLastPageInSameChunk(page)->next_page(); |
| } |
| } |
| |
| #endif |
| |
| |
| void PagedSpace::ClearRSet() { |
| PageIterator it(this, PageIterator::ALL_PAGES); |
| while (it.has_next()) { |
| it.next()->ClearRSet(); |
| } |
| } |
| |
| |
| Object* PagedSpace::FindObject(Address addr) { |
| // Note: this function can only be called before or after mark-compact GC |
| // because it accesses map pointers. |
| ASSERT(!MarkCompactCollector::in_use()); |
| |
| if (!Contains(addr)) return Failure::Exception(); |
| |
| Page* p = Page::FromAddress(addr); |
| ASSERT(IsUsed(p)); |
| Address cur = p->ObjectAreaStart(); |
| Address end = p->AllocationTop(); |
| while (cur < end) { |
| HeapObject* obj = HeapObject::FromAddress(cur); |
| Address next = cur + obj->Size(); |
| if ((cur <= addr) && (addr < next)) return obj; |
| cur = next; |
| } |
| |
| UNREACHABLE(); |
| return Failure::Exception(); |
| } |
| |
| |
| bool PagedSpace::IsUsed(Page* page) { |
| PageIterator it(this, PageIterator::PAGES_IN_USE); |
| while (it.has_next()) { |
| if (page == it.next()) return true; |
| } |
| return false; |
| } |
| |
| |
| void PagedSpace::SetAllocationInfo(AllocationInfo* alloc_info, Page* p) { |
| alloc_info->top = p->ObjectAreaStart(); |
| alloc_info->limit = p->ObjectAreaEnd(); |
| ASSERT(alloc_info->VerifyPagedAllocation()); |
| } |
| |
| |
| void PagedSpace::MCResetRelocationInfo() { |
| // Set page indexes. |
| int i = 0; |
| PageIterator it(this, PageIterator::ALL_PAGES); |
| while (it.has_next()) { |
| Page* p = it.next(); |
| p->mc_page_index = i++; |
| } |
| |
| // Set mc_forwarding_info_ to the first page in the space. |
| SetAllocationInfo(&mc_forwarding_info_, first_page_); |
| // All the bytes in the space are 'available'. We will rediscover |
| // allocated and wasted bytes during GC. |
| accounting_stats_.Reset(); |
| } |
| |
| |
| int PagedSpace::MCSpaceOffsetForAddress(Address addr) { |
| #ifdef DEBUG |
| // The Contains function considers the address at the beginning of a |
| // page in the page, MCSpaceOffsetForAddress considers it is in the |
| // previous page. |
| if (Page::IsAlignedToPageSize(addr)) { |
| ASSERT(Contains(addr - kPointerSize)); |
| } else { |
| ASSERT(Contains(addr)); |
| } |
| #endif |
| |
| // If addr is at the end of a page, it belongs to previous page |
| Page* p = Page::IsAlignedToPageSize(addr) |
| ? Page::FromAllocationTop(addr) |
| : Page::FromAddress(addr); |
| int index = p->mc_page_index; |
| return (index * Page::kPageSize) + p->Offset(addr); |
| } |
| |
| |
| // 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->mc_relocation_top = mc_forwarding_info_.top; |
| 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 = (max_capacity_ - Capacity()) / Page::kObjectAreaSize; |
| if (available_pages <= 0) return false; |
| |
| int desired_pages = Min(available_pages, MemoryAllocator::kPagesPerChunk); |
| Page* p = MemoryAllocator::AllocatePages(desired_pages, &desired_pages, this); |
| if (!p->is_valid()) return false; |
| |
| accounting_stats_.ExpandSpace(desired_pages * Page::kObjectAreaSize); |
| ASSERT(Capacity() <= max_capacity_); |
| |
| MemoryAllocator::SetNextPage(last_page, p); |
| |
| // Clear remembered set of new pages. |
| while (p->is_valid()) { |
| p->ClearRSet(); |
| p = p->next_page(); |
| } |
| |
| return true; |
| } |
| |
| |
| #ifdef DEBUG |
| int PagedSpace::CountTotalPages() { |
| int count = 0; |
| for (Page* p = first_page_; p->is_valid(); p = p->next_page()) { |
| count++; |
| } |
| return count; |
| } |
| #endif |
| |
| |
| void PagedSpace::Shrink() { |
| // Release half of free pages. |
| Page* top_page = AllocationTopPage(); |
| ASSERT(top_page->is_valid()); |
| |
| // Loop over the pages from the top page to the end of the space to count |
| // the number of pages to keep and find the last page to keep. |
| int free_pages = 0; |
| int pages_to_keep = 0; // Of the free pages. |
| Page* last_page_to_keep = top_page; |
| Page* current_page = top_page->next_page(); |
| // Loop over the pages to the end of the space. |
| while (current_page->is_valid()) { |
| // Advance last_page_to_keep every other step to end up at the midpoint. |
| if ((free_pages & 0x1) == 1) { |
| pages_to_keep++; |
| last_page_to_keep = last_page_to_keep->next_page(); |
| } |
| free_pages++; |
| current_page = current_page->next_page(); |
| } |
| |
| // Free pages after last_page_to_keep, and adjust the next_page link. |
| Page* p = MemoryAllocator::FreePages(last_page_to_keep->next_page()); |
| MemoryAllocator::SetNextPage(last_page_to_keep, p); |
| |
| // Since pages are only freed in whole chunks, we may have kept more than |
| // pages_to_keep. |
| while (p->is_valid()) { |
| pages_to_keep++; |
| p = p->next_page(); |
| } |
| |
| // The difference between free_pages and pages_to_keep is the number of |
| // pages actually freed. |
| ASSERT(pages_to_keep <= free_pages); |
| int bytes_freed = (free_pages - pages_to_keep) * Page::kObjectAreaSize; |
| accounting_stats_.ShrinkSpace(bytes_freed); |
| |
| ASSERT(Capacity() == CountTotalPages() * Page::kObjectAreaSize); |
| } |
| |
| |
| bool PagedSpace::EnsureCapacity(int capacity) { |
| if (Capacity() >= capacity) return true; |
| |
| // Start from the allocation top and loop to the last page in the space. |
| Page* last_page = AllocationTopPage(); |
| Page* next_page = last_page->next_page(); |
| while (next_page->is_valid()) { |
| last_page = MemoryAllocator::FindLastPageInSameChunk(next_page); |
| next_page = last_page->next_page(); |
| } |
| |
| // Expand the space until it has the required capacity or expansion fails. |
| do { |
| if (!Expand(last_page)) return false; |
| ASSERT(last_page->next_page()->is_valid()); |
| last_page = |
| MemoryAllocator::FindLastPageInSameChunk(last_page->next_page()); |
| } while (Capacity() < capacity); |
| |
| return true; |
| } |
| |
| |
| #ifdef DEBUG |
| void PagedSpace::Print() { } |
| #endif |
| |
| |
| // ----------------------------------------------------------------------------- |
| // NewSpace implementation |
| |
| |
| 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(); |
| int maximum_semispace_capacity = Heap::SemiSpaceSize(); |
| |
| ASSERT(initial_semispace_capacity <= maximum_semispace_capacity); |
| ASSERT(IsPowerOf2(maximum_semispace_capacity)); |
| maximum_capacity_ = maximum_semispace_capacity; |
| capacity_ = initial_semispace_capacity; |
| |
| // Allocate and setup the histogram arrays if necessary. |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| allocated_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1); |
| promoted_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1); |
| |
| #define SET_NAME(name) allocated_histogram_[name].set_name(#name); \ |
| promoted_histogram_[name].set_name(#name); |
| INSTANCE_TYPE_LIST(SET_NAME) |
| #undef SET_NAME |
| #endif |
| |
| ASSERT(size == 2 * maximum_capacity_); |
| ASSERT(IsAddressAligned(start, size, 0)); |
| |
| if (!to_space_.Setup(start, capacity_, maximum_capacity_)) { |
| return false; |
| } |
| if (!from_space_.Setup(start + maximum_capacity_, |
| capacity_, |
| maximum_capacity_)) { |
| return false; |
| } |
| |
| start_ = start; |
| address_mask_ = ~(size - 1); |
| object_mask_ = address_mask_ | kHeapObjectTag; |
| object_expected_ = reinterpret_cast<uint32_t>(start) | kHeapObjectTag; |
| |
| allocation_info_.top = to_space_.low(); |
| allocation_info_.limit = to_space_.high(); |
| mc_forwarding_info_.top = NULL; |
| mc_forwarding_info_.limit = NULL; |
| |
| ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); |
| return true; |
| } |
| |
| |
| void NewSpace::TearDown() { |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| if (allocated_histogram_) { |
| DeleteArray(allocated_histogram_); |
| allocated_histogram_ = NULL; |
| } |
| if (promoted_histogram_) { |
| DeleteArray(promoted_histogram_); |
| promoted_histogram_ = NULL; |
| } |
| #endif |
| |
| start_ = NULL; |
| capacity_ = 0; |
| allocation_info_.top = NULL; |
| allocation_info_.limit = NULL; |
| mc_forwarding_info_.top = NULL; |
| mc_forwarding_info_.limit = NULL; |
| |
| to_space_.TearDown(); |
| from_space_.TearDown(); |
| } |
| |
| |
| #ifdef ENABLE_HEAP_PROTECTION |
| |
| void NewSpace::Protect() { |
| MemoryAllocator::Protect(ToSpaceLow(), Capacity()); |
| MemoryAllocator::Protect(FromSpaceLow(), Capacity()); |
| } |
| |
| |
| void NewSpace::Unprotect() { |
| MemoryAllocator::Unprotect(ToSpaceLow(), Capacity(), |
| to_space_.executable()); |
| MemoryAllocator::Unprotect(FromSpaceLow(), Capacity(), |
| from_space_.executable()); |
| } |
| |
| #endif |
| |
| |
| void NewSpace::Flip() { |
| SemiSpace tmp = from_space_; |
| from_space_ = to_space_; |
| to_space_ = tmp; |
| } |
| |
| |
| bool NewSpace::Double() { |
| ASSERT(capacity_ <= maximum_capacity_ / 2); |
| // TODO(1240712): Failure to double the from space can result in |
| // semispaces of different sizes. In the event of that failure, the |
| // to space doubling should be rolled back before returning false. |
| if (!to_space_.Double() || !from_space_.Double()) return false; |
| capacity_ *= 2; |
| allocation_info_.limit = to_space_.high(); |
| ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); |
| return true; |
| } |
| |
| |
| 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::MCResetRelocationInfo() { |
| mc_forwarding_info_.top = from_space_.low(); |
| mc_forwarding_info_.limit = from_space_.high(); |
| ASSERT_SEMISPACE_ALLOCATION_INFO(mc_forwarding_info_, from_space_); |
| } |
| |
| |
| void NewSpace::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 |
| // 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. |
| ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); |
| |
| // There should be objects packed in from the low address up to the |
| // allocation pointer. |
| Address current = to_space_.low(); |
| while (current < top()) { |
| HeapObject* object = HeapObject::FromAddress(current); |
| |
| // The first word should be a map, and we expect all map pointers to |
| // be in map space. |
| Map* map = object->map(); |
| ASSERT(map->IsMap()); |
| ASSERT(Heap::map_space()->Contains(map)); |
| |
| // The object should not be code or a map. |
| ASSERT(!object->IsMap()); |
| ASSERT(!object->IsCode()); |
| |
| // The object itself should look OK. |
| object->Verify(); |
| |
| // All the interior pointers should be contained in the heap. |
| VerifyPointersVisitor visitor; |
| int size = object->Size(); |
| object->IterateBody(map->instance_type(), size, &visitor); |
| |
| current += size; |
| } |
| |
| // The allocation pointer should not be in the middle of an object. |
| ASSERT(current == top()); |
| } |
| #endif |
| |
| |
| // ----------------------------------------------------------------------------- |
| // SemiSpace implementation |
| |
| bool SemiSpace::Setup(Address start, |
| int initial_capacity, |
| int maximum_capacity) { |
| // Creates a space in the young generation. The constructor does not |
| // allocate memory from the OS. A SemiSpace is given a contiguous chunk of |
| // memory of size 'capacity' when set up, and does not grow or shrink |
| // otherwise. In the mark-compact collector, the memory region of the from |
| // space is used as the marking stack. It requires contiguous memory |
| // addresses. |
| capacity_ = initial_capacity; |
| maximum_capacity_ = maximum_capacity; |
| |
| if (!MemoryAllocator::CommitBlock(start, capacity_, executable())) { |
| return false; |
| } |
| |
| start_ = start; |
| address_mask_ = ~(maximum_capacity - 1); |
| object_mask_ = address_mask_ | kHeapObjectTag; |
| object_expected_ = reinterpret_cast<uint32_t>(start) | kHeapObjectTag; |
| |
| age_mark_ = start_; |
| return true; |
| } |
| |
| |
| void SemiSpace::TearDown() { |
| start_ = NULL; |
| capacity_ = 0; |
| } |
| |
| |
| bool SemiSpace::Double() { |
| if (!MemoryAllocator::CommitBlock(high(), capacity_, executable())) { |
| return false; |
| } |
| capacity_ *= 2; |
| return true; |
| } |
| |
| |
| #ifdef DEBUG |
| void SemiSpace::Print() { } |
| |
| |
| void SemiSpace::Verify() { } |
| #endif |
| |
| |
| // ----------------------------------------------------------------------------- |
| // SemiSpaceIterator implementation. |
| SemiSpaceIterator::SemiSpaceIterator(NewSpace* space) { |
| Initialize(space, space->bottom(), space->top(), NULL); |
| } |
| |
| |
| SemiSpaceIterator::SemiSpaceIterator(NewSpace* space, |
| HeapObjectCallback size_func) { |
| Initialize(space, space->bottom(), space->top(), size_func); |
| } |
| |
| |
| SemiSpaceIterator::SemiSpaceIterator(NewSpace* space, Address start) { |
| Initialize(space, start, space->top(), NULL); |
| } |
| |
| |
| void SemiSpaceIterator::Initialize(NewSpace* space, Address start, |
| Address end, |
| HeapObjectCallback size_func) { |
| ASSERT(space->ToSpaceContains(start)); |
| ASSERT(space->ToSpaceLow() <= end |
| && end <= space->ToSpaceHigh()); |
| space_ = &space->to_space_; |
| current_ = start; |
| limit_ = end; |
| size_func_ = size_func; |
| } |
| |
| |
| #ifdef DEBUG |
| // A static array of histogram info for each type. |
| static HistogramInfo heap_histograms[LAST_TYPE+1]; |
| static JSObject::SpillInformation js_spill_information; |
| |
| // heap_histograms is shared, always clear it before using it. |
| static void ClearHistograms() { |
| // We reset the name each time, though it hasn't changed. |
| #define DEF_TYPE_NAME(name) heap_histograms[name].set_name(#name); |
| INSTANCE_TYPE_LIST(DEF_TYPE_NAME) |
| #undef DEF_TYPE_NAME |
| |
| #define CLEAR_HISTOGRAM(name) heap_histograms[name].clear(); |
| INSTANCE_TYPE_LIST(CLEAR_HISTOGRAM) |
| #undef CLEAR_HISTOGRAM |
| |
| js_spill_information.Clear(); |
| } |
| |
| |
| static int code_kind_statistics[Code::NUMBER_OF_KINDS]; |
| |
| |
| static void ClearCodeKindStatistics() { |
| for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) { |
| code_kind_statistics[i] = 0; |
| } |
| } |
| |
| |
| static void ReportCodeKindStatistics() { |
| const char* table[Code::NUMBER_OF_KINDS]; |
| |
| #define CASE(name) \ |
| case Code::name: table[Code::name] = #name; \ |
| break |
| |
| for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) { |
| switch (static_cast<Code::Kind>(i)) { |
| CASE(FUNCTION); |
| CASE(STUB); |
| CASE(BUILTIN); |
| CASE(LOAD_IC); |
| CASE(KEYED_LOAD_IC); |
| CASE(STORE_IC); |
| CASE(KEYED_STORE_IC); |
| CASE(CALL_IC); |
| } |
| } |
| |
| #undef CASE |
| |
| PrintF("\n Code kind histograms: \n"); |
| for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) { |
| if (code_kind_statistics[i] > 0) { |
| PrintF(" %-20s: %10d bytes\n", table[i], code_kind_statistics[i]); |
| } |
| } |
| PrintF("\n"); |
| } |
| |
| |
| static int CollectHistogramInfo(HeapObject* obj) { |
| InstanceType type = obj->map()->instance_type(); |
| ASSERT(0 <= type && type <= LAST_TYPE); |
| ASSERT(heap_histograms[type].name() != NULL); |
| heap_histograms[type].increment_number(1); |
| heap_histograms[type].increment_bytes(obj->Size()); |
| |
| if (FLAG_collect_heap_spill_statistics && obj->IsJSObject()) { |
| JSObject::cast(obj)->IncrementSpillStatistics(&js_spill_information); |
| } |
| |
| return obj->Size(); |
| } |
| |
| |
| static void ReportHistogram(bool print_spill) { |
| PrintF("\n Object Histogram:\n"); |
| for (int i = 0; i <= LAST_TYPE; i++) { |
| if (heap_histograms[i].number() > 0) { |
| PrintF(" %-33s%10d (%10d bytes)\n", |
| heap_histograms[i].name(), |
| heap_histograms[i].number(), |
| heap_histograms[i].bytes()); |
| } |
| } |
| PrintF("\n"); |
| |
| // Summarize string types. |
| int string_number = 0; |
| int string_bytes = 0; |
| #define INCREMENT(type, size, name) \ |
| string_number += heap_histograms[type].number(); \ |
| string_bytes += heap_histograms[type].bytes(); |
| STRING_TYPE_LIST(INCREMENT) |
| #undef INCREMENT |
| if (string_number > 0) { |
| PrintF(" %-33s%10d (%10d bytes)\n\n", "STRING_TYPE", string_number, |
| string_bytes); |
| } |
| |
| if (FLAG_collect_heap_spill_statistics && print_spill) { |
| js_spill_information.Print(); |
| } |
| } |
| #endif // DEBUG |
| |
| |
| // Support for statistics gathering for --heap-stats and --log-gc. |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| void NewSpace::ClearHistograms() { |
| for (int i = 0; i <= LAST_TYPE; i++) { |
| allocated_histogram_[i].clear(); |
| promoted_histogram_[i].clear(); |
| } |
| } |
| |
| // Because the copying collector does not touch garbage objects, we iterate |
| // the new space before a collection to get a histogram of allocated objects. |
| // This only happens (1) when compiled with DEBUG and the --heap-stats flag is |
| // set, or when compiled with ENABLE_LOGGING_AND_PROFILING and the --log-gc |
| // flag is set. |
| void NewSpace::CollectStatistics() { |
| ClearHistograms(); |
| SemiSpaceIterator it(this); |
| while (it.has_next()) RecordAllocation(it.next()); |
| } |
| |
| |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| static void DoReportStatistics(HistogramInfo* info, const char* description) { |
| LOG(HeapSampleBeginEvent("NewSpace", description)); |
| // Lump all the string types together. |
| int string_number = 0; |
| int string_bytes = 0; |
| #define INCREMENT(type, size, name) \ |
| string_number += info[type].number(); \ |
| string_bytes += info[type].bytes(); |
| STRING_TYPE_LIST(INCREMENT) |
| #undef INCREMENT |
| if (string_number > 0) { |
| LOG(HeapSampleItemEvent("STRING_TYPE", string_number, string_bytes)); |
| } |
| |
| // Then do the other types. |
| for (int i = FIRST_NONSTRING_TYPE; i <= LAST_TYPE; ++i) { |
| if (info[i].number() > 0) { |
| LOG(HeapSampleItemEvent(info[i].name(), info[i].number(), |
| info[i].bytes())); |
| } |
| } |
| LOG(HeapSampleEndEvent("NewSpace", description)); |
| } |
| #endif // ENABLE_LOGGING_AND_PROFILING |
| |
| |
| void NewSpace::ReportStatistics() { |
| #ifdef DEBUG |
| if (FLAG_heap_stats) { |
| float pct = static_cast<float>(Available()) / Capacity(); |
| PrintF(" capacity: %d, available: %d, %%%d\n", |
| Capacity(), Available(), static_cast<int>(pct*100)); |
| PrintF("\n Object Histogram:\n"); |
| for (int i = 0; i <= LAST_TYPE; i++) { |
| if (allocated_histogram_[i].number() > 0) { |
| PrintF(" %-33s%10d (%10d bytes)\n", |
| allocated_histogram_[i].name(), |
| allocated_histogram_[i].number(), |
| allocated_histogram_[i].bytes()); |
| } |
| } |
| PrintF("\n"); |
| } |
| #endif // DEBUG |
| |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| if (FLAG_log_gc) { |
| DoReportStatistics(allocated_histogram_, "allocated"); |
| DoReportStatistics(promoted_histogram_, "promoted"); |
| } |
| #endif // ENABLE_LOGGING_AND_PROFILING |
| } |
| |
| |
| void NewSpace::RecordAllocation(HeapObject* obj) { |
| InstanceType type = obj->map()->instance_type(); |
| ASSERT(0 <= type && type <= LAST_TYPE); |
| allocated_histogram_[type].increment_number(1); |
| allocated_histogram_[type].increment_bytes(obj->Size()); |
| } |
| |
| |
| void NewSpace::RecordPromotion(HeapObject* obj) { |
| InstanceType type = obj->map()->instance_type(); |
| ASSERT(0 <= type && type <= LAST_TYPE); |
| promoted_histogram_[type].increment_number(1); |
| promoted_histogram_[type].increment_bytes(obj->Size()); |
| } |
| #endif // defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| |
| |
| // ----------------------------------------------------------------------------- |
| // Free lists for old object spaces implementation |
| |
| void FreeListNode::set_size(int size_in_bytes) { |
| ASSERT(size_in_bytes > 0); |
| ASSERT(IsAligned(size_in_bytes, kPointerSize)); |
| |
| // We write a map and possibly size information to the block. If the block |
| // is big enough to be a ByteArray with at least one extra word (the next |
| // pointer), we set its map to be the byte array map and its size to an |
| // 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 > Array::kHeaderSize) { |
| set_map(Heap::byte_array_map()); |
| ByteArray::cast(this)->set_length(ByteArray::LengthFor(size_in_bytes)); |
| } else if (size_in_bytes == kPointerSize) { |
| set_map(Heap::one_word_filler_map()); |
| } else if (size_in_bytes == 2 * kPointerSize) { |
| set_map(Heap::two_word_filler_map()); |
| } else { |
| UNREACHABLE(); |
| } |
| ASSERT(Size() == size_in_bytes); |
| } |
| |
| |
| Address FreeListNode::next() { |
| ASSERT(map() == Heap::byte_array_map()); |
| ASSERT(Size() >= kNextOffset + kPointerSize); |
| return Memory::Address_at(address() + kNextOffset); |
| } |
| |
| |
| void FreeListNode::set_next(Address next) { |
| ASSERT(map() == Heap::byte_array_map()); |
| ASSERT(Size() >= kNextOffset + kPointerSize); |
| Memory::Address_at(address() + kNextOffset) = next; |
| } |
| |
| |
| OldSpaceFreeList::OldSpaceFreeList(AllocationSpace owner) : owner_(owner) { |
| 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 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 OldSpaceFreeList::Free(Address start, int size_in_bytes) { |
| #ifdef DEBUG |
| for (int i = 0; i < size_in_bytes; i += kPointerSize) { |
| Memory::Address_at(start + i) = kZapValue; |
| } |
| #endif |
| FreeListNode* node = FreeListNode::FromAddress(start); |
| node->set_size(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(free_[index].head_node_); |
| free_[index].head_node_ = node->address(); |
| available_ += size_in_bytes; |
| needs_rebuild_ = true; |
| return 0; |
| } |
| |
| |
| Object* 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 (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()) == NULL) RemoveSize(index); |
| available_ -= size_in_bytes; |
| *wasted_bytes = 0; |
| 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(size_in_bytes, owner_); |
| } |
| 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()) == NULL) { |
| free_[rem].next_size_ = free_[cur].next_size_; |
| } else { |
| free_[rem].next_size_ = cur; |
| } |
| // Add the remainder block. |
| rem_node->set_size(rem_bytes); |
| rem_node->set_next(free_[rem].head_node_); |
| free_[rem].head_node_ = rem_node->address(); |
| } else { |
| // If this was the last block of size cur, remove the size. |
| if ((free_[cur].head_node_ = cur_node->next()) == NULL) { |
| finger_ = prev; |
| free_[prev].next_size_ = free_[cur].next_size_; |
| } |
| if (rem_bytes < kMinBlockSize) { |
| // Too-small remainder is wasted. |
| rem_node->set_size(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(rem_bytes); |
| rem_node->set_next(free_[rem].head_node_); |
| free_[rem].head_node_ = rem_node->address(); |
| if (rem_node->next() == NULL) InsertSize(rem); |
| } |
| available_ -= size_in_bytes; |
| *wasted_bytes = 0; |
| return cur_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(); |
| } |
| } |
| return false; |
| } |
| #endif |
| |
| |
| MapSpaceFreeList::MapSpaceFreeList(AllocationSpace owner) { |
| owner_ = owner; |
| Reset(); |
| } |
| |
| |
| void MapSpaceFreeList::Reset() { |
| available_ = 0; |
| head_ = NULL; |
| } |
| |
| |
| void MapSpaceFreeList::Free(Address start) { |
| #ifdef DEBUG |
| for (int i = 0; i < Map::kSize; i += kPointerSize) { |
| Memory::Address_at(start + i) = kZapValue; |
| } |
| #endif |
| FreeListNode* node = FreeListNode::FromAddress(start); |
| node->set_size(Map::kSize); |
| node->set_next(head_); |
| head_ = node->address(); |
| available_ += Map::kSize; |
| } |
| |
| |
| Object* MapSpaceFreeList::Allocate() { |
| if (head_ == NULL) { |
| return Failure::RetryAfterGC(Map::kSize, owner_); |
| } |
| |
| FreeListNode* node = FreeListNode::FromAddress(head_); |
| head_ = node->next(); |
| available_ -= Map::kSize; |
| return node; |
| } |
| |
| |
| // ----------------------------------------------------------------------------- |
| // OldSpace implementation |
| |
| void OldSpace::PrepareForMarkCompact(bool 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(); |
| mc_end_of_relocation_ = bottom(); |
| ASSERT(Available() == Capacity()); |
| } else { |
| // During a non-compacting collection, everything below the linear |
| // allocation pointer is considered allocated (everything above is |
| // available) and we will rediscover available and wasted bytes during |
| // the collection. |
| accounting_stats_.AllocateBytes(free_list_.available()); |
| accounting_stats_.FillWastedBytes(Waste()); |
| } |
| |
| // Clear the free list before a full GC---it will be rebuilt afterward. |
| free_list_.Reset(); |
| } |
| |
| |
| void OldSpace::MCAdjustRelocationEnd(Address address, int size_in_bytes) { |
| ASSERT(Contains(address)); |
| Address current_top = mc_end_of_relocation_; |
| Page* current_page = Page::FromAllocationTop(current_top); |
| |
| // No more objects relocated to this page? Move to the next. |
| ASSERT(current_top <= current_page->mc_relocation_top); |
| if (current_top == current_page->mc_relocation_top) { |
| // The space should already be properly expanded. |
| Page* next_page = current_page->next_page(); |
| CHECK(next_page->is_valid()); |
| mc_end_of_relocation_ = next_page->ObjectAreaStart(); |
| } |
| ASSERT(mc_end_of_relocation_ == address); |
| mc_end_of_relocation_ += size_in_bytes; |
| } |
| |
| |
| 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); |
| |
| // 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 += p->mc_relocation_top - p->ObjectAreaStart(); |
| if (it.has_next()) { |
| // Free the space at the top of the page. We cannot use |
| // p->mc_relocation_top after the call to Free (because Free will clear |
| // remembered set bits). |
| int extra_size = p->ObjectAreaEnd() - p->mc_relocation_top; |
| if (extra_size > 0) { |
| int wasted_bytes = free_list_.Free(p->mc_relocation_top, 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()); |
| } |
| |
| |
| // 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. |
| int wasted_bytes; |
| Object* result = free_list_.Allocate(size_in_bytes, &wasted_bytes); |
| accounting_stats_.WasteBytes(wasted_bytes); |
| if (!result->IsFailure()) { |
| accounting_stats_.AllocateBytes(size_in_bytes); |
| return HeapObject::cast(result); |
| } |
| |
| // 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; |
| } |
| |
| |
| // 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()); |
| // Add the block at the top of this page to the free list. |
| int free_size = 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); |
| } |
| SetAllocationInfo(&allocation_info_, current_page->next_page()); |
| return AllocateLinearly(&allocation_info_, size_in_bytes); |
| } |
| |
| |
| #ifdef DEBUG |
| // We do not assume that the PageIterator works, because it depends on the |
| // invariants we are checking during verification. |
| void OldSpace::Verify() { |
| // 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(MemoryAllocator::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 { |
| // Unless this is the last page in the space containing allocated |
| // objects, the allocation top should be at the object area end. |
| 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; |
| } else { |
| ASSERT(top == current_page->ObjectAreaEnd()); |
| } |
| |
| // 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)); |
| |
| // The object should not be a map. |
| ASSERT(!object->IsMap()); |
| |
| // The object itself should look OK. |
| object->Verify(); |
| |
| // All the interior pointers should be contained in the heap and have |
| // their remembered set bits set if they point to new space. Code |
| // objects do not have remembered set bits that we care about. |
| VerifyPointersAndRSetVisitor rset_visitor; |
| VerifyPointersVisitor no_rset_visitor; |
| int size = object->Size(); |
| if (object->IsCode()) { |
| Code::cast(object)->ConvertICTargetsFromAddressToObject(); |
| object->IterateBody(map->instance_type(), size, &no_rset_visitor); |
| Code::cast(object)->ConvertICTargetsFromObjectToAddress(); |
| } else { |
| object->IterateBody(map->instance_type(), size, &rset_visitor); |
| } |
| |
| current += size; |
| } |
| |
| // The allocation pointer should not be in the middle of an object. |
| ASSERT(current == top); |
| } |
| |
| current_page = current_page->next_page(); |
| } |
| } |
| |
| |
| struct CommentStatistic { |
| const char* comment; |
| int size; |
| int count; |
| void Clear() { |
| comment = NULL; |
| size = 0; |
| count = 0; |
| } |
| }; |
| |
| |
| // must be small, since an iteration is used for lookup |
| const int kMaxComments = 64; |
| static CommentStatistic comments_statistics[kMaxComments+1]; |
| |
| |
| void PagedSpace::ReportCodeStatistics() { |
| ReportCodeKindStatistics(); |
| PrintF("Code comment statistics (\" [ comment-txt : size/ " |
| "count (average)\"):\n"); |
| for (int i = 0; i <= kMaxComments; i++) { |
| const CommentStatistic& cs = comments_statistics[i]; |
| if (cs.size > 0) { |
| PrintF(" %-30s: %10d/%6d (%d)\n", cs.comment, cs.size, cs.count, |
| cs.size/cs.count); |
| } |
| } |
| PrintF("\n"); |
| } |
| |
| |
| void PagedSpace::ResetCodeStatistics() { |
| ClearCodeKindStatistics(); |
| for (int i = 0; i < kMaxComments; i++) comments_statistics[i].Clear(); |
| comments_statistics[kMaxComments].comment = "Unknown"; |
| comments_statistics[kMaxComments].size = 0; |
| comments_statistics[kMaxComments].count = 0; |
| } |
| |
| |
| // Adds comment to 'comment_statistics' table. Performance OK sa long as |
| // 'kMaxComments' is small |
| static void EnterComment(const char* comment, int delta) { |
| // Do not count empty comments |
| if (delta <= 0) return; |
| CommentStatistic* cs = &comments_statistics[kMaxComments]; |
| // Search for a free or matching entry in 'comments_statistics': 'cs' |
| // points to result. |
| for (int i = 0; i < kMaxComments; i++) { |
| if (comments_statistics[i].comment == NULL) { |
| cs = &comments_statistics[i]; |
| cs->comment = comment; |
| break; |
| } else if (strcmp(comments_statistics[i].comment, comment) == 0) { |
| cs = &comments_statistics[i]; |
| break; |
| } |
| } |
| // Update entry for 'comment' |
| cs->size += delta; |
| cs->count += 1; |
| } |
| |
| |
| // Call for each nested comment start (start marked with '[ xxx', end marked |
| // with ']'. RelocIterator 'it' must point to a comment reloc info. |
| static void CollectCommentStatistics(RelocIterator* it) { |
| ASSERT(!it->done()); |
| ASSERT(it->rinfo()->rmode() == RelocInfo::COMMENT); |
| const char* tmp = reinterpret_cast<const char*>(it->rinfo()->data()); |
| if (tmp[0] != '[') { |
| // Not a nested comment; skip |
| return; |
| } |
| |
| // Search for end of nested comment or a new nested comment |
| const char* const comment_txt = |
| reinterpret_cast<const char*>(it->rinfo()->data()); |
| const byte* prev_pc = it->rinfo()->pc(); |
| int flat_delta = 0; |
| it->next(); |
| while (true) { |
| // All nested comments must be terminated properly, and therefore exit |
| // from loop. |
| ASSERT(!it->done()); |
| if (it->rinfo()->rmode() == RelocInfo::COMMENT) { |
| const char* const txt = |
| reinterpret_cast<const char*>(it->rinfo()->data()); |
| flat_delta += it->rinfo()->pc() - prev_pc; |
| if (txt[0] == ']') break; // End of nested comment |
| // A new comment |
| CollectCommentStatistics(it); |
| // Skip code that was covered with previous comment |
| prev_pc = it->rinfo()->pc(); |
| } |
| it->next(); |
| } |
| EnterComment(comment_txt, flat_delta); |
| } |
| |
| |
| // Collects code size statistics: |
| // - by code kind |
| // - by code comment |
| void PagedSpace::CollectCodeStatistics() { |
| HeapObjectIterator obj_it(this); |
| while (obj_it.has_next()) { |
| HeapObject* obj = obj_it.next(); |
| if (obj->IsCode()) { |
| Code* code = Code::cast(obj); |
| code_kind_statistics[code->kind()] += code->Size(); |
| RelocIterator it(code); |
| int delta = 0; |
| const byte* prev_pc = code->instruction_start(); |
| while (!it.done()) { |
| if (it.rinfo()->rmode() == RelocInfo::COMMENT) { |
| delta += it.rinfo()->pc() - prev_pc; |
| CollectCommentStatistics(&it); |
| prev_pc = it.rinfo()->pc(); |
| } |
| it.next(); |
| } |
| |
| ASSERT(code->instruction_start() <= prev_pc && |
| prev_pc <= code->relocation_start()); |
| delta += code->relocation_start() - prev_pc; |
| EnterComment("NoComment", delta); |
| } |
| } |
| } |
| |
| |
| void OldSpace::ReportStatistics() { |
| int pct = Available() * 100 / Capacity(); |
| PrintF(" capacity: %d, waste: %d, available: %d, %%%d\n", |
| Capacity(), Waste(), Available(), pct); |
| |
| // Report remembered set statistics. |
| int rset_marked_pointers = 0; |
| int rset_marked_arrays = 0; |
| int rset_marked_array_elements = 0; |
| int cross_gen_pointers = 0; |
| int cross_gen_array_elements = 0; |
| |
| PageIterator page_it(this, PageIterator::PAGES_IN_USE); |
| while (page_it.has_next()) { |
| Page* p = page_it.next(); |
| |
| for (Address rset_addr = p->RSetStart(); |
| rset_addr < p->RSetEnd(); |
| rset_addr += kIntSize) { |
| int rset = Memory::int_at(rset_addr); |
| if (rset != 0) { |
| // Bits were set |
| int intoff = rset_addr - p->address(); |
| int bitoff = 0; |
| for (; bitoff < kBitsPerInt; ++bitoff) { |
| if ((rset & (1 << bitoff)) != 0) { |
| int bitpos = intoff*kBitsPerByte + bitoff; |
| Address slot = p->OffsetToAddress(bitpos << kObjectAlignmentBits); |
| Object** obj = reinterpret_cast<Object**>(slot); |
| if (*obj == Heap::fixed_array_map()) { |
| rset_marked_arrays++; |
| FixedArray* fa = FixedArray::cast(HeapObject::FromAddress(slot)); |
| |
| rset_marked_array_elements += fa->length(); |
| // Manually inline FixedArray::IterateBody |
| Address elm_start = slot + FixedArray::kHeaderSize; |
| Address elm_stop = elm_start + fa->length() * kPointerSize; |
| for (Address elm_addr = elm_start; |
| elm_addr < elm_stop; elm_addr += kPointerSize) { |
| // Filter non-heap-object pointers |
| Object** elm_p = reinterpret_cast<Object**>(elm_addr); |
| if (Heap::InNewSpace(*elm_p)) |
| cross_gen_array_elements++; |
| } |
| } else { |
| rset_marked_pointers++; |
| if (Heap::InNewSpace(*obj)) |
| cross_gen_pointers++; |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| pct = rset_marked_pointers == 0 ? |
| 0 : cross_gen_pointers * 100 / rset_marked_pointers; |
| PrintF(" rset-marked pointers %d, to-new-space %d (%%%d)\n", |
| rset_marked_pointers, cross_gen_pointers, pct); |
| PrintF(" rset_marked arrays %d, ", rset_marked_arrays); |
| PrintF(" elements %d, ", rset_marked_array_elements); |
| pct = rset_marked_array_elements == 0 ? 0 |
| : cross_gen_array_elements * 100 / rset_marked_array_elements; |
| PrintF(" pointers to new space %d (%%%d)\n", cross_gen_array_elements, pct); |
| PrintF(" total rset-marked bits %d\n", |
| (rset_marked_pointers + rset_marked_arrays)); |
| pct = (rset_marked_pointers + rset_marked_array_elements) == 0 ? 0 |
| : (cross_gen_pointers + cross_gen_array_elements) * 100 / |
| (rset_marked_pointers + rset_marked_array_elements); |
| PrintF(" total rset pointers %d, true cross generation ones %d (%%%d)\n", |
| (rset_marked_pointers + rset_marked_array_elements), |
| (cross_gen_pointers + cross_gen_array_elements), |
| pct); |
| |
| ClearHistograms(); |
| HeapObjectIterator obj_it(this); |
| while (obj_it.has_next()) { CollectHistogramInfo(obj_it.next()); } |
| ReportHistogram(true); |
| } |
| |
| |
| // Dump the range of remembered set words between [start, end) corresponding |
| // to the pointers starting at object_p. The allocation_top is an object |
| // pointer which should not be read past. This is important for large object |
| // pages, where some bits in the remembered set range do not correspond to |
| // allocated addresses. |
| static void PrintRSetRange(Address start, Address end, Object** object_p, |
| Address allocation_top) { |
| Address rset_address = start; |
| |
| // If the range starts on on odd numbered word (eg, for large object extra |
| // remembered set ranges), print some spaces. |
| if ((reinterpret_cast<uint32_t>(start) / kIntSize) % 2 == 1) { |
| PrintF(" "); |
| } |
| |
| // Loop over all the words in the range. |
| while (rset_address < end) { |
| uint32_t rset_word = Memory::uint32_at(rset_address); |
| int bit_position = 0; |
| |
| // Loop over all the bits in the word. |
| while (bit_position < kBitsPerInt) { |
| if (object_p == reinterpret_cast<Object**>(allocation_top)) { |
| // Print a bar at the allocation pointer. |
| PrintF("|"); |
| } else if (object_p > reinterpret_cast<Object**>(allocation_top)) { |
| // Do not dereference object_p past the allocation pointer. |
| PrintF("#"); |
| } else if ((rset_word & (1 << bit_position)) == 0) { |
| // Print a dot for zero bits. |
| PrintF("."); |
| } else if (Heap::InNewSpace(*object_p)) { |
| // Print an X for one bits for pointers to new space. |
| PrintF("X"); |
| } else { |
| // Print a circle for one bits for pointers to old space. |
| PrintF("o"); |
| } |
| |
| // Print a space after every 8th bit except the last. |
| if (bit_position % 8 == 7 && bit_position != (kBitsPerInt - 1)) { |
| PrintF(" "); |
| } |
| |
| // Advance to next bit. |
| bit_position++; |
| object_p++; |
| } |
| |
| // Print a newline after every odd numbered word, otherwise a space. |
| if ((reinterpret_cast<uint32_t>(rset_address) / kIntSize) % 2 == 1) { |
| PrintF("\n"); |
| } else { |
| PrintF(" "); |
| } |
| |
| // Advance to next remembered set word. |
| rset_address += kIntSize; |
| } |
| } |
| |
| |
| void PagedSpace::DoPrintRSet(const char* space_name) { |
| PageIterator it(this, PageIterator::PAGES_IN_USE); |
| while (it.has_next()) { |
| Page* p = it.next(); |
| PrintF("%s page 0x%x:\n", space_name, p); |
| PrintRSetRange(p->RSetStart(), p->RSetEnd(), |
| reinterpret_cast<Object**>(p->ObjectAreaStart()), |
| p->AllocationTop()); |
| PrintF("\n"); |
| } |
| } |
| |
| |
| void OldSpace::PrintRSet() { DoPrintRSet("old"); } |
| #endif |
| |
| // ----------------------------------------------------------------------------- |
| // MapSpace implementation |
| |
| void MapSpace::PrepareForMarkCompact(bool will_compact) { |
| if (will_compact) { |
| // Reset relocation info. |
| MCResetRelocationInfo(); |
| |
| // 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(); |
| } |
| |
| // 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 MapSpace::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 += page_top - page->ObjectAreaStart(); |
| if (it.has_next()) { |
| accounting_stats_.WasteBytes(page->ObjectAreaEnd() - 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* MapSpace::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. |
| 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. The |
| // map space free list implicitly assumes that all free blocks are map |
| // sized. |
| if (size_in_bytes == Map::kSize) { |
| Object* result = free_list_.Allocate(); |
| if (!result->IsFailure()) { |
| accounting_stats_.AllocateBytes(size_in_bytes); |
| return HeapObject::cast(result); |
| } |
| } |
| |
| // 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* MapSpace::AllocateInNextPage(Page* current_page, |
| int size_in_bytes) { |
| ASSERT(current_page->next_page()->is_valid()); |
| ASSERT(current_page->ObjectAreaEnd() - allocation_info_.top == kPageExtra); |
| accounting_stats_.WasteBytes(kPageExtra); |
| SetAllocationInfo(&allocation_info_, current_page->next_page()); |
| return AllocateLinearly(&allocation_info_, size_in_bytes); |
| } |
| |
| |
| #ifdef DEBUG |
| // We do not assume that the PageIterator works, because it depends on the |
| // invariants we are checking during verification. |
| void MapSpace::Verify() { |
| // 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(MemoryAllocator::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 { |
| // Unless this is the last page in the space containing allocated |
| // objects, the allocation top should be at a constant offset from the |
| // object area end. |
| 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; |
| } else { |
| ASSERT(top == current_page->ObjectAreaEnd() - kPageExtra); |
| } |
| |
| // 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)); |
| |
| // The object should be a map or a byte array. |
| ASSERT(object->IsMap() || object->IsByteArray()); |
| |
| // The object itself should look OK. |
| object->Verify(); |
| |
| // All the interior pointers should be contained in the heap and |
| // have their remembered set bits set if they point to new space. |
| VerifyPointersAndRSetVisitor visitor; |
| 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); |
| } |
| |
| current_page = current_page->next_page(); |
| } |
| } |
| |
| |
| void MapSpace::ReportStatistics() { |
| int pct = Available() * 100 / Capacity(); |
| PrintF(" capacity: %d, waste: %d, available: %d, %%%d\n", |
| Capacity(), Waste(), Available(), pct); |
| |
| // Report remembered set statistics. |
| int rset_marked_pointers = 0; |
| int cross_gen_pointers = 0; |
| |
| PageIterator page_it(this, PageIterator::PAGES_IN_USE); |
| while (page_it.has_next()) { |
| Page* p = page_it.next(); |
| |
| for (Address rset_addr = p->RSetStart(); |
| rset_addr < p->RSetEnd(); |
| rset_addr += kIntSize) { |
| int rset = Memory::int_at(rset_addr); |
| if (rset != 0) { |
| // Bits were set |
| int intoff = rset_addr - p->address(); |
| int bitoff = 0; |
| for (; bitoff < kBitsPerInt; ++bitoff) { |
| if ((rset & (1 << bitoff)) != 0) { |
| int bitpos = intoff*kBitsPerByte + bitoff; |
| Address slot = p->OffsetToAddress(bitpos << kObjectAlignmentBits); |
| Object** obj = reinterpret_cast<Object**>(slot); |
| rset_marked_pointers++; |
| if (Heap::InNewSpace(*obj)) |
| cross_gen_pointers++; |
| } |
| } |
| } |
| } |
| } |
| |
| pct = rset_marked_pointers == 0 ? |
| 0 : cross_gen_pointers * 100 / rset_marked_pointers; |
| PrintF(" rset-marked pointers %d, to-new-space %d (%%%d)\n", |
| rset_marked_pointers, cross_gen_pointers, pct); |
| |
| ClearHistograms(); |
| HeapObjectIterator obj_it(this); |
| while (obj_it.has_next()) { CollectHistogramInfo(obj_it.next()); } |
| ReportHistogram(false); |
| } |
| |
| |
| void MapSpace::PrintRSet() { DoPrintRSet("map"); } |
| #endif |
| |
| |
| // ----------------------------------------------------------------------------- |
| // LargeObjectIterator |
| |
| LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space) { |
| current_ = space->first_chunk_; |
| size_func_ = NULL; |
| } |
| |
| |
| LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space, |
| HeapObjectCallback size_func) { |
| current_ = space->first_chunk_; |
| size_func_ = size_func; |
| } |
| |
| |
| HeapObject* LargeObjectIterator::next() { |
| ASSERT(has_next()); |
| HeapObject* object = current_->GetObject(); |
| current_ = current_->next(); |
| return object; |
| } |
| |
| |
| // ----------------------------------------------------------------------------- |
| // LargeObjectChunk |
| |
| LargeObjectChunk* LargeObjectChunk::New(int size_in_bytes, |
| size_t* chunk_size, |
| Executability executable) { |
| size_t requested = ChunkSizeFor(size_in_bytes); |
| void* mem = MemoryAllocator::AllocateRawMemory(requested, |
| chunk_size, |
| executable); |
| if (mem == NULL) return NULL; |
| LOG(NewEvent("LargeObjectChunk", mem, *chunk_size)); |
| if (*chunk_size < requested) { |
| MemoryAllocator::FreeRawMemory(mem, *chunk_size); |
| LOG(DeleteEvent("LargeObjectChunk", mem)); |
| return NULL; |
| } |
| return reinterpret_cast<LargeObjectChunk*>(mem); |
| } |
| |
| |
| int LargeObjectChunk::ChunkSizeFor(int size_in_bytes) { |
| int os_alignment = OS::AllocateAlignment(); |
| if (os_alignment < Page::kPageSize) |
| size_in_bytes += (Page::kPageSize - os_alignment); |
| return size_in_bytes + Page::kObjectStartOffset; |
| } |
| |
| // ----------------------------------------------------------------------------- |
| // LargeObjectSpace |
| |
| LargeObjectSpace::LargeObjectSpace(AllocationSpace id) |
| : Space(id, NOT_EXECUTABLE), // Managed on a per-allocation basis |
| first_chunk_(NULL), |
| size_(0), |
| page_count_(0) {} |
| |
| |
| bool LargeObjectSpace::Setup() { |
| first_chunk_ = NULL; |
| size_ = 0; |
| page_count_ = 0; |
| return true; |
| } |
| |
| |
| void LargeObjectSpace::TearDown() { |
| while (first_chunk_ != NULL) { |
| LargeObjectChunk* chunk = first_chunk_; |
| first_chunk_ = first_chunk_->next(); |
| LOG(DeleteEvent("LargeObjectChunk", chunk->address())); |
| MemoryAllocator::FreeRawMemory(chunk->address(), chunk->size()); |
| } |
| |
| size_ = 0; |
| page_count_ = 0; |
| } |
| |
| |
| #ifdef ENABLE_HEAP_PROTECTION |
| |
| void LargeObjectSpace::Protect() { |
| LargeObjectChunk* chunk = first_chunk_; |
| while (chunk != NULL) { |
| MemoryAllocator::Protect(chunk->address(), chunk->size()); |
| chunk = chunk->next(); |
| } |
| } |
| |
| |
| void LargeObjectSpace::Unprotect() { |
| LargeObjectChunk* chunk = first_chunk_; |
| while (chunk != NULL) { |
| bool is_code = chunk->GetObject()->IsCode(); |
| MemoryAllocator::Unprotect(chunk->address(), chunk->size(), |
| is_code ? EXECUTABLE : NOT_EXECUTABLE); |
| chunk = chunk->next(); |
| } |
| } |
| |
| #endif |
| |
| |
| Object* 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() && Heap::OldGenerationAllocationLimitReached()) { |
| return Failure::RetryAfterGC(requested_size, identity()); |
| } |
| |
| size_t chunk_size; |
| LargeObjectChunk* chunk = |
| LargeObjectChunk::New(requested_size, &chunk_size, executable); |
| if (chunk == NULL) { |
| return Failure::RetryAfterGC(requested_size, identity()); |
| } |
| |
| size_ += chunk_size; |
| page_count_++; |
| chunk->set_next(first_chunk_); |
| chunk->set_size(chunk_size); |
| first_chunk_ = chunk; |
| |
| // Set the object address and size in the page header and clear its |
| // remembered set. |
| Page* page = Page::FromAddress(RoundUp(chunk->address(), Page::kPageSize)); |
| 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. |
| ASSERT((chunk_size & 0x1) == 0); |
| page->is_normal_page &= ~0x1; |
| page->ClearRSet(); |
| int extra_bytes = requested_size - object_size; |
| if (extra_bytes > 0) { |
| // The extra memory for the remembered set should be cleared. |
| memset(object_address + object_size, 0, extra_bytes); |
| } |
| |
| return HeapObject::FromAddress(object_address); |
| } |
| |
| |
| Object* LargeObjectSpace::AllocateRawCode(int size_in_bytes) { |
| ASSERT(0 < size_in_bytes); |
| return AllocateRawInternal(size_in_bytes, |
| size_in_bytes, |
| EXECUTABLE); |
| } |
| |
| |
| Object* LargeObjectSpace::AllocateRawFixedArray(int size_in_bytes) { |
| ASSERT(0 < size_in_bytes); |
| int extra_rset_bytes = ExtraRSetBytesFor(size_in_bytes); |
| return AllocateRawInternal(size_in_bytes + extra_rset_bytes, |
| size_in_bytes, |
| NOT_EXECUTABLE); |
| } |
| |
| |
| Object* LargeObjectSpace::AllocateRaw(int size_in_bytes) { |
| ASSERT(0 < size_in_bytes); |
| return AllocateRawInternal(size_in_bytes, |
| size_in_bytes, |
| NOT_EXECUTABLE); |
| } |
| |
| |
| // GC support |
| Object* LargeObjectSpace::FindObject(Address a) { |
| for (LargeObjectChunk* chunk = first_chunk_; |
| chunk != NULL; |
| chunk = chunk->next()) { |
| Address chunk_address = chunk->address(); |
| if (chunk_address <= a && a < chunk_address + chunk->size()) { |
| return chunk->GetObject(); |
| } |
| } |
| return Failure::Exception(); |
| } |
| |
| |
| void LargeObjectSpace::ClearRSet() { |
| ASSERT(Page::is_rset_in_use()); |
| |
| LargeObjectIterator it(this); |
| while (it.has_next()) { |
| HeapObject* object = it.next(); |
| // We only have code, sequential strings, or fixed arrays in large |
| // object space, and only fixed arrays need remembered set support. |
| if (object->IsFixedArray()) { |
| // Clear the normal remembered set region of the page; |
| Page* page = Page::FromAddress(object->address()); |
| page->ClearRSet(); |
| |
| // Clear the extra remembered set. |
| int size = object->Size(); |
| int extra_rset_bytes = ExtraRSetBytesFor(size); |
| memset(object->address() + size, 0, extra_rset_bytes); |
| } |
| } |
| } |
| |
| |
| void LargeObjectSpace::IterateRSet(ObjectSlotCallback copy_object_func) { |
| ASSERT(Page::is_rset_in_use()); |
| |
| LargeObjectIterator it(this); |
| while (it.has_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. |
| HeapObject* object = it.next(); |
| if (object->IsFixedArray()) { |
| // Iterate the normal page remembered set range. |
| Page* page = Page::FromAddress(object->address()); |
| Address object_end = object->address() + object->Size(); |
| Heap::IterateRSetRange(page->ObjectAreaStart(), |
| Min(page->ObjectAreaEnd(), object_end), |
| page->RSetStart(), |
| copy_object_func); |
| |
| // Iterate the extra array elements. |
| if (object_end > page->ObjectAreaEnd()) { |
| Heap::IterateRSetRange(page->ObjectAreaEnd(), object_end, |
| object_end, copy_object_func); |
| } |
| } |
| } |
| } |
| |
| |
| void LargeObjectSpace::FreeUnmarkedObjects() { |
| LargeObjectChunk* previous = NULL; |
| LargeObjectChunk* current = first_chunk_; |
| while (current != NULL) { |
| HeapObject* object = current->GetObject(); |
| if (object->IsMarked()) { |
| object->ClearMark(); |
| MarkCompactCollector::tracer()->decrement_marked_count(); |
| previous = current; |
| current = current->next(); |
| } else { |
| Address chunk_address = current->address(); |
| size_t chunk_size = current->size(); |
| |
| // Cut the chunk out from the chunk list. |
| current = current->next(); |
| if (previous == NULL) { |
| first_chunk_ = current; |
| } else { |
| previous->set_next(current); |
| } |
| |
| // Free the chunk. |
| if (object->IsCode()) { |
| LOG(CodeDeleteEvent(object->address())); |
| } |
| size_ -= chunk_size; |
| page_count_--; |
| MemoryAllocator::FreeRawMemory(chunk_address, chunk_size); |
| LOG(DeleteEvent("LargeObjectChunk", chunk_address)); |
| } |
| } |
| } |
| |
| |
| bool LargeObjectSpace::Contains(HeapObject* object) { |
| Address address = object->address(); |
| Page* page = Page::FromAddress(address); |
| |
| SLOW_ASSERT(!page->IsLargeObjectPage() |
| || !FindObject(address)->IsFailure()); |
| |
| return page->IsLargeObjectPage(); |
| } |
| |
| |
| #ifdef DEBUG |
| // We do not assume that the large object iterator works, because it depends |
| // on the invariants we are checking during verification. |
| void LargeObjectSpace::Verify() { |
| for (LargeObjectChunk* chunk = first_chunk_; |
| chunk != NULL; |
| chunk = chunk->next()) { |
| // Each chunk contains an object that starts at the large object page's |
| // object area start. |
| HeapObject* object = chunk->GetObject(); |
| Page* page = Page::FromAddress(object->address()); |
| ASSERT(object->address() == page->ObjectAreaStart()); |
| |
| // 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)); |
| |
| // We have only code, sequential strings, fixed arrays, and byte arrays |
| // in large object space. |
| ASSERT(object->IsCode() || object->IsSeqString() |
| || object->IsFixedArray() || object->IsByteArray()); |
| |
| // The object itself should look OK. |
| object->Verify(); |
| |
| // Byte arrays and strings don't have interior pointers. |
| if (object->IsCode()) { |
| VerifyPointersVisitor code_visitor; |
| Code::cast(object)->ConvertICTargetsFromAddressToObject(); |
| object->IterateBody(map->instance_type(), |
| object->Size(), |
| &code_visitor); |
| Code::cast(object)->ConvertICTargetsFromObjectToAddress(); |
| } 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 IsRSetSet. |
| FixedArray* array = FixedArray::cast(object); |
| for (int j = 0; j < array->length(); j++) { |
| Object* element = array->get(j); |
| if (element->IsHeapObject()) { |
| HeapObject* element_object = HeapObject::cast(element); |
| ASSERT(Heap::Contains(element_object)); |
| ASSERT(element_object->map()->IsMap()); |
| if (Heap::InNewSpace(element_object)) { |
| ASSERT(Page::IsRSetSet(object->address(), |
| FixedArray::kHeaderSize + j * kPointerSize)); |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| |
| void LargeObjectSpace::Print() { |
| LargeObjectIterator it(this); |
| while (it.has_next()) { |
| it.next()->Print(); |
| } |
| } |
| |
| |
| void LargeObjectSpace::ReportStatistics() { |
| PrintF(" size: %d\n", size_); |
| int num_objects = 0; |
| ClearHistograms(); |
| LargeObjectIterator it(this); |
| while (it.has_next()) { |
| num_objects++; |
| CollectHistogramInfo(it.next()); |
| } |
| |
| PrintF(" number of objects %d\n", num_objects); |
| if (num_objects > 0) ReportHistogram(false); |
| } |
| |
| |
| void LargeObjectSpace::CollectCodeStatistics() { |
| LargeObjectIterator obj_it(this); |
| while (obj_it.has_next()) { |
| HeapObject* obj = obj_it.next(); |
| if (obj->IsCode()) { |
| Code* code = Code::cast(obj); |
| code_kind_statistics[code->kind()] += code->Size(); |
| } |
| } |
| } |
| |
| |
| void LargeObjectSpace::PrintRSet() { |
| LargeObjectIterator it(this); |
| while (it.has_next()) { |
| HeapObject* object = it.next(); |
| if (object->IsFixedArray()) { |
| Page* page = Page::FromAddress(object->address()); |
| |
| Address allocation_top = object->address() + object->Size(); |
| PrintF("large page 0x%x:\n", page); |
| PrintRSetRange(page->RSetStart(), page->RSetEnd(), |
| reinterpret_cast<Object**>(object->address()), |
| allocation_top); |
| int extra_array_bytes = object->Size() - Page::kObjectAreaSize; |
| int extra_rset_bits = RoundUp(extra_array_bytes / kPointerSize, |
| kBitsPerInt); |
| PrintF("------------------------------------------------------------" |
| "-----------\n"); |
| PrintRSetRange(allocation_top, |
| allocation_top + extra_rset_bits / kBitsPerByte, |
| reinterpret_cast<Object**>(object->address() |
| + Page::kObjectAreaSize), |
| allocation_top); |
| PrintF("\n"); |
| } |
| } |
| } |
| #endif // DEBUG |
| |
| } } // namespace v8::internal |