| // 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()) |
| |
| intptr_t Page::watermark_invalidated_mark_ = Page::WATERMARK_INVALIDATED; |
| |
| // ---------------------------------------------------------------------------- |
| // 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 |
| } |
| |
| |
| HeapObject* HeapObjectIterator::FromNextPage() { |
| if (cur_addr_ == end_addr_) return NULL; |
| |
| 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(); |
| |
| if (cur_addr_ == end_addr_) return NULL; |
| ASSERT(cur_addr_ < cur_limit_); |
| #ifdef DEBUG |
| Verify(); |
| #endif |
| return FromCurrentPage(); |
| } |
| |
| |
| #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) : 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 |
| |
| List<CodeRange::FreeBlock> CodeRange::free_list_(0); |
| List<CodeRange::FreeBlock> CodeRange::allocation_list_(0); |
| int CodeRange::current_allocation_block_index_ = 0; |
| VirtualMemory* CodeRange::code_range_ = NULL; |
| |
| |
| bool CodeRange::Setup(const size_t requested) { |
| ASSERT(code_range_ == NULL); |
| |
| code_range_ = new VirtualMemory(requested); |
| CHECK(code_range_ != NULL); |
| if (!code_range_->IsReserved()) { |
| delete code_range_; |
| code_range_ = NULL; |
| return false; |
| } |
| |
| // We are sure that we have mapped a block of requested addresses. |
| ASSERT(code_range_->size() == requested); |
| LOG(NewEvent("CodeRange", code_range_->address(), requested)); |
| allocation_list_.Add(FreeBlock(code_range_->address(), code_range_->size())); |
| current_allocation_block_index_ = 0; |
| return true; |
| } |
| |
| |
| int CodeRange::CompareFreeBlockAddress(const FreeBlock* left, |
| const FreeBlock* right) { |
| // The entire point of CodeRange is that the difference between two |
| // addresses in the range can be represented as a signed 32-bit int, |
| // so the cast is semantically correct. |
| return static_cast<int>(left->start - right->start); |
| } |
| |
| |
| void CodeRange::GetNextAllocationBlock(size_t requested) { |
| for (current_allocation_block_index_++; |
| current_allocation_block_index_ < allocation_list_.length(); |
| current_allocation_block_index_++) { |
| if (requested <= allocation_list_[current_allocation_block_index_].size) { |
| return; // Found a large enough allocation block. |
| } |
| } |
| |
| // Sort and merge the free blocks on the free list and the allocation list. |
| free_list_.AddAll(allocation_list_); |
| allocation_list_.Clear(); |
| free_list_.Sort(&CompareFreeBlockAddress); |
| for (int i = 0; i < free_list_.length();) { |
| FreeBlock merged = free_list_[i]; |
| i++; |
| // Add adjacent free blocks to the current merged block. |
| while (i < free_list_.length() && |
| free_list_[i].start == merged.start + merged.size) { |
| merged.size += free_list_[i].size; |
| i++; |
| } |
| if (merged.size > 0) { |
| allocation_list_.Add(merged); |
| } |
| } |
| free_list_.Clear(); |
| |
| for (current_allocation_block_index_ = 0; |
| current_allocation_block_index_ < allocation_list_.length(); |
| current_allocation_block_index_++) { |
| if (requested <= allocation_list_[current_allocation_block_index_].size) { |
| return; // Found a large enough allocation block. |
| } |
| } |
| |
| // Code range is full or too fragmented. |
| V8::FatalProcessOutOfMemory("CodeRange::GetNextAllocationBlock"); |
| } |
| |
| |
| |
| 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 |
| // call V8::FatalProcessOutOfMemory if it cannot find a large enough block. |
| GetNextAllocationBlock(requested); |
| } |
| // Commit the requested memory at the start of the current allocation block. |
| *allocated = RoundUp(requested, Page::kPageSize); |
| FreeBlock current = allocation_list_[current_allocation_block_index_]; |
| if (*allocated >= current.size - Page::kPageSize) { |
| // Don't leave a small free block, useless for a large object or chunk. |
| *allocated = current.size; |
| } |
| ASSERT(*allocated <= current.size); |
| if (!code_range_->Commit(current.start, *allocated, true)) { |
| *allocated = 0; |
| return NULL; |
| } |
| allocation_list_[current_allocation_block_index_].start += *allocated; |
| allocation_list_[current_allocation_block_index_].size -= *allocated; |
| if (*allocated == current.size) { |
| GetNextAllocationBlock(0); // This block is used up, get the next one. |
| } |
| return current.start; |
| } |
| |
| |
| void CodeRange::FreeRawMemory(void* address, size_t length) { |
| free_list_.Add(FreeBlock(address, length)); |
| code_range_->Uncommit(address, length); |
| } |
| |
| |
| void CodeRange::TearDown() { |
| delete code_range_; // Frees all memory in the virtual memory range. |
| code_range_ = NULL; |
| free_list_.Free(); |
| allocation_list_.Free(); |
| } |
| |
| |
| // ----------------------------------------------------------------------------- |
| // 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; |
| if (executable == EXECUTABLE && CodeRange::exists()) { |
| mem = CodeRange::AllocateRawMemory(requested, allocated); |
| } else { |
| mem = OS::Allocate(requested, allocated, (executable == EXECUTABLE)); |
| } |
| int alloced = static_cast<int>(*allocated); |
| size_ += alloced; |
| #ifdef DEBUG |
| ZapBlock(reinterpret_cast<Address>(mem), alloced); |
| #endif |
| Counters::memory_allocated.Increment(alloced); |
| return mem; |
| } |
| |
| |
| void MemoryAllocator::FreeRawMemory(void* mem, size_t length) { |
| #ifdef DEBUG |
| ZapBlock(reinterpret_cast<Address>(mem), length); |
| #endif |
| if (CodeRange::contains(static_cast<Address>(mem))) { |
| CodeRange::FreeRawMemory(mem, length); |
| } else { |
| OS::Free(mem, length); |
| } |
| Counters::memory_allocated.Decrement(static_cast<int>(length)); |
| size_ -= static_cast<int>(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_ += static_cast<int>(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 static_cast<int>((RoundDown(start + size, Page::kPageSize) |
| - RoundUp(start, Page::kPageSize)) >> 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 = static_cast<int>(chunk_size >> 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); |
| } |
| #ifdef DEBUG |
| ZapBlock(start, size); |
| #endif |
| Counters::memory_allocated.Increment(static_cast<int>(size)); |
| |
| // So long as we correctly overestimated the number of chunks we should not |
| // run out of chunk ids. |
| CHECK(!OutOfChunkIds()); |
| int chunk_id = Pop(); |
| chunks_[chunk_id].init(start, size, owner); |
| return InitializePagesInChunk(chunk_id, *num_pages, owner); |
| } |
| |
| |
| 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; |
| #ifdef DEBUG |
| ZapBlock(start, size); |
| #endif |
| Counters::memory_allocated.Increment(static_cast<int>(size)); |
| return true; |
| } |
| |
| |
| bool MemoryAllocator::UncommitBlock(Address start, size_t size) { |
| ASSERT(start != NULL); |
| ASSERT(size > 0); |
| ASSERT(initial_chunk_ != NULL); |
| ASSERT(InInitialChunk(start)); |
| ASSERT(InInitialChunk(start + size - 1)); |
| |
| if (!initial_chunk_->Uncommit(start, size)) return false; |
| Counters::memory_allocated.Decrement(static_cast<int>(size)); |
| return true; |
| } |
| |
| |
| void MemoryAllocator::ZapBlock(Address start, size_t size) { |
| for (size_t s = 0; s + kPointerSize <= size; s += kPointerSize) { |
| Memory::Address_at(start + s) = kZapValue; |
| } |
| } |
| |
| |
| 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->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); |
| } |
| |
| |
| 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::FreeAllPages(PagedSpace* space) { |
| for (int i = 0, length = chunks_.length(); i < length; i++) { |
| if (chunks_[i].owner() == space) { |
| DeleteChunk(i); |
| } |
| } |
| } |
| |
| |
| 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(static_cast<int>(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 |
| |
| |
| 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 |
| |
| 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_); |
| |
| // 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 (Capacity() > 0); |
| } |
| |
| |
| void PagedSpace::TearDown() { |
| MemoryAllocator::FreeAllPages(this); |
| first_page_ = NULL; |
| 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::MarkAllPagesClean() { |
| PageIterator it(this, PageIterator::ALL_PAGES); |
| while (it.has_next()) { |
| it.next()->SetRegionMarks(Page::kAllRegionsCleanMarks); |
| } |
| } |
| |
| |
| 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->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 = (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); |
| |
| // 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; |
| } |
| |
| |
| #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() { |
| if (!page_list_is_chunk_ordered_) { |
| // We can't shrink space if pages is not chunk-ordered |
| // (see comment for class MemoryAllocator for definition). |
| return; |
| } |
| |
| // Release half of free pages. |
| Page* top_page = AllocationTopPage(); |
| ASSERT(top_page->is_valid()); |
| |
| // Count the number of pages we would like to free. |
| int pages_to_free = 0; |
| for (Page* p = top_page->next_page(); p->is_valid(); p = p->next_page()) { |
| pages_to_free++; |
| } |
| |
| // Free pages after top_page. |
| Page* p = MemoryAllocator::FreePages(top_page->next_page()); |
| MemoryAllocator::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); |
| } |
| |
| |
| 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 |
| |
| |
| #ifdef DEBUG |
| // We do not assume that the PageIterator works, because it depends on the |
| // invariants we are checking during verification. |
| void PagedSpace::Verify(ObjectVisitor* visitor) { |
| // The allocation pointer should be valid, and it should be in a page in the |
| // space. |
| ASSERT(allocation_info_.VerifyPagedAllocation()); |
| Page* top_page = Page::FromAllocationTop(allocation_info_.top); |
| ASSERT(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 { |
| Address top = current_page->AllocationTop(); |
| if (current_page == top_page) { |
| ASSERT(top == allocation_info_.top); |
| // The next page will be above the allocation top. |
| above_allocation_top = true; |
| } |
| |
| // It should be packed with objects from the bottom to the top. |
| Address current = current_page->ObjectAreaStart(); |
| while (current < top) { |
| HeapObject* object = HeapObject::FromAddress(current); |
| |
| // The first word should be a map, and we expect all map pointers to |
| // be in map space. |
| Map* map = object->map(); |
| ASSERT(map->IsMap()); |
| ASSERT(Heap::map_space()->Contains(map)); |
| |
| // Perform space-specific object verification. |
| VerifyObject(object); |
| |
| // The object itself should look OK. |
| object->Verify(); |
| |
| // All the interior pointers should be contained in the heap and |
| // have page regions covering intergenerational references should be |
| // marked dirty. |
| int size = object->Size(); |
| object->IterateBody(map->instance_type(), size, visitor); |
| |
| current += size; |
| } |
| |
| // The allocation pointer should not be in the middle of an object. |
| ASSERT(current == top); |
| } |
| |
| current_page = current_page->next_page(); |
| } |
| } |
| #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::MaxSemiSpaceSize(); |
| |
| ASSERT(initial_semispace_capacity <= maximum_semispace_capacity); |
| ASSERT(IsPowerOf2(maximum_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 * Heap::ReservedSemiSpaceSize()); |
| ASSERT(IsAddressAligned(start, size, 0)); |
| |
| if (!to_space_.Setup(start, |
| initial_semispace_capacity, |
| maximum_semispace_capacity)) { |
| return false; |
| } |
| if (!from_space_.Setup(start + maximum_semispace_capacity, |
| initial_semispace_capacity, |
| maximum_semispace_capacity)) { |
| return false; |
| } |
| |
| start_ = start; |
| address_mask_ = ~(size - 1); |
| object_mask_ = address_mask_ | kHeapObjectTagMask; |
| object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag; |
| |
| allocation_info_.top = to_space_.low(); |
| allocation_info_.limit = to_space_.high(); |
| mc_forwarding_info_.top = NULL; |
| mc_forwarding_info_.limit = NULL; |
| |
| 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; |
| 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; |
| } |
| |
| |
| void NewSpace::Grow() { |
| ASSERT(Capacity() < MaximumCapacity()); |
| if (to_space_.Grow()) { |
| // Only grow from space if we managed to grow to space. |
| if (!from_space_.Grow()) { |
| // If we managed to grow to space but couldn't grow from space, |
| // attempt to shrink to space. |
| if (!to_space_.ShrinkTo(from_space_.Capacity())) { |
| // We are in an inconsistent state because we could not |
| // commit/uncommit memory from new space. |
| V8::FatalProcessOutOfMemory("Failed to grow new space."); |
| } |
| } |
| } |
| allocation_info_.limit = to_space_.high(); |
| ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); |
| } |
| |
| |
| void NewSpace::Shrink() { |
| int new_capacity = Max(InitialCapacity(), 2 * Size()); |
| 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. |
| 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 (!to_space_.GrowTo(from_space_.Capacity())) { |
| // We are in an inconsistent state because we could not |
| // commit/uncommit memory from new space. |
| V8::FatalProcessOutOfMemory("Failed to shrink new space."); |
| } |
| } |
| } |
| allocation_info_.limit = to_space_.high(); |
| ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); |
| } |
| |
| |
| 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 |
| |
| |
| bool SemiSpace::Commit() { |
| ASSERT(!is_committed()); |
| if (!MemoryAllocator::CommitBlock(start_, capacity_, executable())) { |
| return false; |
| } |
| committed_ = true; |
| return true; |
| } |
| |
| |
| bool SemiSpace::Uncommit() { |
| ASSERT(is_committed()); |
| if (!MemoryAllocator::UncommitBlock(start_, capacity_)) { |
| return false; |
| } |
| committed_ = false; |
| return true; |
| } |
| |
| |
| // ----------------------------------------------------------------------------- |
| // 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. |
| initial_capacity_ = initial_capacity; |
| capacity_ = initial_capacity; |
| maximum_capacity_ = maximum_capacity; |
| committed_ = false; |
| |
| start_ = start; |
| address_mask_ = ~(maximum_capacity - 1); |
| object_mask_ = address_mask_ | kHeapObjectTagMask; |
| object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag; |
| age_mark_ = start_; |
| |
| return Commit(); |
| } |
| |
| |
| void SemiSpace::TearDown() { |
| start_ = NULL; |
| capacity_ = 0; |
| } |
| |
| |
| 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 (!MemoryAllocator::CommitBlock(high(), extra, executable())) { |
| return false; |
| } |
| capacity_ += extra; |
| return true; |
| } |
| |
| |
| bool SemiSpace::GrowTo(int new_capacity) { |
| ASSERT(new_capacity <= maximum_capacity_); |
| ASSERT(new_capacity > capacity_); |
| size_t delta = new_capacity - capacity_; |
| ASSERT(IsAligned(delta, OS::AllocateAlignment())); |
| if (!MemoryAllocator::CommitBlock(high(), delta, executable())) { |
| return false; |
| } |
| capacity_ = new_capacity; |
| return true; |
| } |
| |
| |
| bool SemiSpace::ShrinkTo(int new_capacity) { |
| ASSERT(new_capacity >= initial_capacity_); |
| ASSERT(new_capacity < capacity_); |
| size_t delta = capacity_ - new_capacity; |
| ASSERT(IsAligned(delta, OS::AllocateAlignment())); |
| if (!MemoryAllocator::UncommitBlock(high() - delta, delta)) { |
| return false; |
| } |
| capacity_ = new_capacity; |
| 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] = { NULL }; |
| |
| #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); |
| CASE(KEYED_CALL_IC); |
| CASE(BINARY_OP_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(" %-34s%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, camel_name) \ |
| string_number += heap_histograms[type].number(); \ |
| string_bytes += heap_histograms[type].bytes(); |
| STRING_TYPE_LIST(INCREMENT) |
| #undef INCREMENT |
| if (string_number > 0) { |
| PrintF(" %-34s%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); |
| for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) |
| RecordAllocation(obj); |
| } |
| |
| |
| #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, camel_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(" %-34s%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 > 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) { |
| set_map(Heap::raw_unchecked_two_pointer_filler_map()); |
| } else { |
| UNREACHABLE(); |
| } |
| // We would like to ASSERT(Size() == size_in_bytes) but this would fail during |
| // deserialization because the byte array map is not done yet. |
| } |
| |
| |
| Address FreeListNode::next() { |
| ASSERT(IsFreeListNode(this)); |
| if (map() == Heap::raw_unchecked_byte_array_map()) { |
| ASSERT(Size() >= kNextOffset + kPointerSize); |
| return Memory::Address_at(address() + kNextOffset); |
| } else { |
| return Memory::Address_at(address() + kPointerSize); |
| } |
| } |
| |
| |
| void FreeListNode::set_next(Address next) { |
| ASSERT(IsFreeListNode(this)); |
| if (map() == Heap::raw_unchecked_byte_array_map()) { |
| ASSERT(Size() >= kNextOffset + kPointerSize); |
| Memory::Address_at(address() + kNextOffset) = next; |
| } else { |
| Memory::Address_at(address() + kPointerSize) = 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 |
| MemoryAllocator::ZapBlock(start, size_in_bytes); |
| #endif |
| FreeListNode* node = FreeListNode::FromAddress(start); |
| node->set_size(size_in_bytes); |
| |
| // We don't use the freelists in compacting mode. This makes it more like a |
| // GC that only has mark-sweep-compact and doesn't have a mark-sweep |
| // collector. |
| if (FLAG_always_compact) { |
| return size_in_bytes; |
| } |
| |
| // Early return to drop too-small blocks on the floor (one or two word |
| // blocks cannot hold a map pointer, a size field, and a pointer to the |
| // next block in the free list). |
| if (size_in_bytes < kMinBlockSize) { |
| return size_in_bytes; |
| } |
| |
| // 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; |
| 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(size_in_bytes, 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()) == 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 |
| |
| |
| FixedSizeFreeList::FixedSizeFreeList(AllocationSpace owner, int object_size) |
| : owner_(owner), object_size_(object_size) { |
| Reset(); |
| } |
| |
| |
| void FixedSizeFreeList::Reset() { |
| available_ = 0; |
| head_ = tail_ = NULL; |
| } |
| |
| |
| void FixedSizeFreeList::Free(Address start) { |
| #ifdef DEBUG |
| MemoryAllocator::ZapBlock(start, object_size_); |
| #endif |
| // We only use the freelists with mark-sweep. |
| ASSERT(!MarkCompactCollector::IsCompacting()); |
| FreeListNode* node = FreeListNode::FromAddress(start); |
| node->set_size(object_size_); |
| node->set_next(NULL); |
| if (head_ == NULL) { |
| tail_ = head_ = node->address(); |
| } else { |
| FreeListNode::FromAddress(tail_)->set_next(node->address()); |
| tail_ = node->address(); |
| } |
| available_ += object_size_; |
| } |
| |
| |
| Object* FixedSizeFreeList::Allocate() { |
| if (head_ == NULL) { |
| return Failure::RetryAfterGC(object_size_, owner_); |
| } |
| |
| ASSERT(!FLAG_always_compact); // We only use the freelists with mark-sweep. |
| FreeListNode* node = FreeListNode::FromAddress(head_); |
| head_ = node->next(); |
| available_ -= object_size_; |
| return node; |
| } |
| |
| |
| // ----------------------------------------------------------------------------- |
| // OldSpace implementation |
| |
| void OldSpace::PrepareForMarkCompact(bool will_compact) { |
| // Call prepare of the super class. |
| PagedSpace::PrepareForMarkCompact(will_compact); |
| |
| if (will_compact) { |
| // Reset relocation info. During a compacting collection, everything in |
| // the space is considered 'available' and we will rediscover live data |
| // and waste during the collection. |
| MCResetRelocationInfo(); |
| ASSERT(Available() == Capacity()); |
| } else { |
| // During a non-compacting collection, everything below the linear |
| // allocation pointer is considered allocated (everything above is |
| // available) and we will rediscover available and wasted bytes during |
| // the collection. |
| accounting_stats_.AllocateBytes(free_list_.available()); |
| accounting_stats_.FillWastedBytes(Waste()); |
| } |
| |
| // Clear the free list before a full GC---it will be rebuilt afterward. |
| free_list_.Reset(); |
| } |
| |
| |
| 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 += |
| 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()); |
| } |
| |
| |
| bool NewSpace::ReserveSpace(int bytes) { |
| // We can't reliably unpack a partial snapshot that needs more new space |
| // space than the minimum NewSpace size. |
| ASSERT(bytes <= InitialCapacity()); |
| Address limit = allocation_info_.limit; |
| Address top = allocation_info_.top; |
| return limit - top >= bytes; |
| } |
| |
| |
| void PagedSpace::FreePages(Page* prev, Page* last) { |
| if (last == AllocationTopPage()) { |
| // Pages are already at the end of used pages. |
| return; |
| } |
| |
| Page* first = NULL; |
| |
| // Remove pages from the list. |
| if (prev == NULL) { |
| first = first_page_; |
| first_page_ = last->next_page(); |
| } else { |
| first = prev->next_page(); |
| MemoryAllocator::SetNextPage(prev, last->next_page()); |
| } |
| |
| // Attach it after the last page. |
| MemoryAllocator::SetNextPage(last_page_, first); |
| last_page_ = last; |
| MemoryAllocator::SetNextPage(last, NULL); |
| |
| // Clean them up. |
| do { |
| first->InvalidateWatermark(true); |
| first->SetAllocationWatermark(first->ObjectAreaStart()); |
| first->SetCachedAllocationWatermark(first->ObjectAreaStart()); |
| first->SetRegionMarks(Page::kAllRegionsCleanMarks); |
| first = first->next_page(); |
| } while (first != NULL); |
| |
| // Order of pages in this space might no longer be consistent with |
| // order of pages in chunks. |
| page_list_is_chunk_ordered_ = false; |
| } |
| |
| |
| void PagedSpace::PrepareForMarkCompact(bool will_compact) { |
| if (will_compact) { |
| // MarkCompact collector relies on WAS_IN_USE_BEFORE_MC page flag |
| // to skip unused pages. Update flag value for all pages in space. |
| 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; |
| } |
| } |
| |
| if (!page_list_is_chunk_ordered_) { |
| Page* new_last_in_use = Page::FromAddress(NULL); |
| MemoryAllocator::RelinkPageListInChunkOrder(this, |
| &first_page_, |
| &last_page_, |
| &new_last_in_use); |
| ASSERT(new_last_in_use->is_valid()); |
| |
| 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. |
| last_in_use->SetAllocationWatermark(last_in_use->AllocationTop()); |
| |
| int size_in_bytes = static_cast<int>(PageAllocationLimit(last_in_use) - |
| last_in_use->AllocationTop()); |
| |
| if (size_in_bytes > 0) { |
| // There is still some space left on this page. Create a fake |
| // object which will occupy all free space on this page. |
| // Otherwise iterators would not be able to scan this page |
| // correctly. |
| |
| Heap::CreateFillerObjectAt(last_in_use->AllocationTop(), |
| size_in_bytes); |
| } |
| |
| // New last in use page was in the middle of the list before |
| // sorting so it full. |
| SetTop(new_last_in_use->AllocationTop()); |
| |
| ASSERT(AllocationTopPage() == new_last_in_use); |
| ASSERT(AllocationTopPage()->WasInUseBeforeMC()); |
| } |
| |
| PageIterator pages_in_use_iterator(this, PageIterator::PAGES_IN_USE); |
| while (pages_in_use_iterator.has_next()) { |
| Page* p = pages_in_use_iterator.next(); |
| if (!p->WasInUseBeforeMC()) { |
| // Empty page is in the middle of a sequence of used pages. |
| // Create a fake object which will occupy all free space on this page. |
| // Otherwise iterators would not be able to scan this page correctly. |
| int size_in_bytes = static_cast<int>(PageAllocationLimit(p) - |
| p->ObjectAreaStart()); |
| |
| p->SetAllocationWatermark(p->ObjectAreaStart()); |
| Heap::CreateFillerObjectAt(p->ObjectAreaStart(), size_in_bytes); |
| } |
| } |
| |
| page_list_is_chunk_ordered_ = true; |
| } |
| } |
| } |
| |
| |
| 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; |
| } |
| |
| |
| // 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; |
| } |
| |
| |
| // 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 = free_list_.Allocate(size_in_bytes, &wasted_bytes); |
| accounting_stats_.WasteBytes(wasted_bytes); |
| if (!result->IsFailure()) { |
| 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; |
| } |
| |
| |
| 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); |
| } |
| } |
| |
| |
| 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_); |
| } |
| } |
| |
| |
| // 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); |
| } |
| |
| |
| #ifdef DEBUG |
| 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 += static_cast<int>(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); |
| for (HeapObject* obj = obj_it.next(); obj != NULL; 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 += static_cast<int>(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 += static_cast<int>(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); |
| |
| ClearHistograms(); |
| HeapObjectIterator obj_it(this); |
| for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) |
| CollectHistogramInfo(obj); |
| ReportHistogram(true); |
| } |
| #endif |
| |
| // ----------------------------------------------------------------------------- |
| // FixedSpace implementation |
| |
| void FixedSpace::PrepareForMarkCompact(bool will_compact) { |
| // Call prepare of the super class. |
| PagedSpace::PrepareForMarkCompact(will_compact); |
| |
| 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 = free_list_.Allocate(); |
| if (!result->IsFailure()) { |
| 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); |
| } |
| |
| |
| #ifdef DEBUG |
| void FixedSpace::ReportStatistics() { |
| int pct = Available() * 100 / Capacity(); |
| PrintF(" capacity: %d, waste: %d, available: %d, %%%d\n", |
| Capacity(), Waste(), Available(), pct); |
| |
| ClearHistograms(); |
| HeapObjectIterator obj_it(this); |
| for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) |
| CollectHistogramInfo(obj); |
| ReportHistogram(false); |
| } |
| #endif |
| |
| |
| // ----------------------------------------------------------------------------- |
| // MapSpace implementation |
| |
| void MapSpace::PrepareForMarkCompact(bool will_compact) { |
| // Call prepare of the super class. |
| FixedSpace::PrepareForMarkCompact(will_compact); |
| |
| if (will_compact) { |
| // Initialize map index entry. |
| int page_count = 0; |
| PageIterator it(this, PageIterator::ALL_PAGES); |
| while (it.has_next()) { |
| ASSERT_MAP_PAGE_INDEX(page_count); |
| |
| Page* p = it.next(); |
| ASSERT(p->mc_page_index == page_count); |
| |
| page_addresses_[page_count++] = p->address(); |
| } |
| } |
| } |
| |
| |
| #ifdef DEBUG |
| void MapSpace::VerifyObject(HeapObject* object) { |
| // The object should be a map or a free-list node. |
| ASSERT(object->IsMap() || object->IsByteArray()); |
| } |
| #endif |
| |
| |
| // ----------------------------------------------------------------------------- |
| // GlobalPropertyCellSpace implementation |
| |
| #ifdef DEBUG |
| void CellSpace::VerifyObject(HeapObject* object) { |
| // The object should be a global object property cell or a free-list node. |
| ASSERT(object->IsJSGlobalPropertyCell() || |
| object->map() == Heap::two_pointer_filler_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() { |
| if (current_ == NULL) return NULL; |
| |
| 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 = 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(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_ += static_cast<int>(chunk_size); |
| page_count_++; |
| chunk->set_next(first_chunk_); |
| chunk->set_size(chunk_size); |
| first_chunk_ = chunk; |
| |
| // Initialize page header. |
| 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->SetIsLargeObjectPage(true); |
| page->SetRegionMarks(Page::kAllRegionsCleanMarks); |
| 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); |
| return AllocateRawInternal(size_in_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::IterateDirtyRegions(ObjectSlotCallback copy_object) { |
| LargeObjectIterator it(this); |
| for (HeapObject* object = it.next(); object != NULL; object = it.next()) { |
| // We only have code, sequential strings, or fixed arrays in large |
| // object space, and only fixed arrays can possibly contain pointers to |
| // the young generation. |
| if (object->IsFixedArray()) { |
| Page* page = Page::FromAddress(object->address()); |
| uint32_t marks = page->GetRegionMarks(); |
| uint32_t newmarks = Page::kAllRegionsCleanMarks; |
| |
| if (marks != Page::kAllRegionsCleanMarks) { |
| // For a large page a single dirty mark corresponds to several |
| // regions (modulo 32). So we treat a large page as a sequence of |
| // normal pages of size Page::kPageSize having same dirty marks |
| // and subsequently iterate dirty regions on each of these pages. |
| Address start = object->address(); |
| Address end = page->ObjectAreaEnd(); |
| Address object_end = start + object->Size(); |
| |
| // Iterate regions of the first normal page covering object. |
| uint32_t first_region_number = page->GetRegionNumberForAddress(start); |
| newmarks |= |
| Heap::IterateDirtyRegions(marks >> first_region_number, |
| start, |
| end, |
| &Heap::IteratePointersInDirtyRegion, |
| copy_object) << first_region_number; |
| |
| start = end; |
| end = start + Page::kPageSize; |
| while (end <= object_end) { |
| // Iterate next 32 regions. |
| newmarks |= |
| Heap::IterateDirtyRegions(marks, |
| start, |
| end, |
| &Heap::IteratePointersInDirtyRegion, |
| copy_object); |
| start = end; |
| end = start + Page::kPageSize; |
| } |
| |
| if (start != object_end) { |
| // Iterate the last piece of an object which is less than |
| // Page::kPageSize. |
| newmarks |= |
| Heap::IterateDirtyRegions(marks, |
| start, |
| object_end, |
| &Heap::IteratePointersInDirtyRegion, |
| copy_object); |
| } |
| |
| page->SetRegionMarks(newmarks); |
| } |
| } |
| } |
| } |
| |
| |
| void LargeObjectSpace::FreeUnmarkedObjects() { |
| LargeObjectChunk* previous = NULL; |
| LargeObjectChunk* current = first_chunk_; |
| 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. |
| MarkCompactCollector::ReportDeleteIfNeeded(object); |
| size_ -= static_cast<int>(chunk_size); |
| page_count_--; |
| MemoryAllocator::FreeRawMemory(chunk_address, chunk_size); |
| LOG(DeleteEvent("LargeObjectChunk", chunk_address)); |
| } |
| } |
| } |
| |
| |
| bool LargeObjectSpace::Contains(HeapObject* object) { |
| Address address = object->address(); |
| if (Heap::new_space()->Contains(address)) { |
| return false; |
| } |
| 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, external strings |
| // (sequential strings that have been morphed into external |
| // strings), fixed arrays, and byte arrays in large object space. |
| ASSERT(object->IsCode() || object->IsSeqString() || |
| object->IsExternalString() || 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; |
| object->IterateBody(map->instance_type(), |
| 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); |
| if (element->IsHeapObject()) { |
| 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)); |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| |
| void LargeObjectSpace::Print() { |
| LargeObjectIterator it(this); |
| for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) { |
| obj->Print(); |
| } |
| } |
| |
| |
| void LargeObjectSpace::ReportStatistics() { |
| PrintF(" size: %d\n", size_); |
| int num_objects = 0; |
| ClearHistograms(); |
| LargeObjectIterator it(this); |
| for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) { |
| num_objects++; |
| CollectHistogramInfo(obj); |
| } |
| |
| PrintF(" number of objects %d\n", num_objects); |
| if (num_objects > 0) ReportHistogram(false); |
| } |
| |
| |
| void LargeObjectSpace::CollectCodeStatistics() { |
| LargeObjectIterator obj_it(this); |
| for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) { |
| if (obj->IsCode()) { |
| Code* code = Code::cast(obj); |
| code_kind_statistics[code->kind()] += code->Size(); |
| } |
| } |
| } |
| #endif // DEBUG |
| |
| } } // namespace v8::internal |