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Diffstat (limited to 'V8Binding/v8/src/spaces.cc')
| -rw-r--r-- | V8Binding/v8/src/spaces.cc | 2789 |
1 files changed, 0 insertions, 2789 deletions
diff --git a/V8Binding/v8/src/spaces.cc b/V8Binding/v8/src/spaces.cc deleted file mode 100644 index 43abaa4..0000000 --- a/V8Binding/v8/src/spaces.cc +++ /dev/null @@ -1,2789 +0,0 @@ -// Copyright 2006-2008 the V8 project authors. All rights reserved. -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following -// disclaimer in the documentation and/or other materials provided -// with the distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived -// from this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - -#include "v8.h" - -#include "macro-assembler.h" -#include "mark-compact.h" -#include "platform.h" - -namespace v8 { -namespace internal { - -// For contiguous spaces, top should be in the space (or at the end) and limit -// should be the end of the space. -#define ASSERT_SEMISPACE_ALLOCATION_INFO(info, space) \ - ASSERT((space).low() <= (info).top \ - && (info).top <= (space).high() \ - && (info).limit == (space).high()) - - -// ---------------------------------------------------------------------------- -// HeapObjectIterator - -HeapObjectIterator::HeapObjectIterator(PagedSpace* space) { - Initialize(space->bottom(), space->top(), NULL); -} - - -HeapObjectIterator::HeapObjectIterator(PagedSpace* space, - HeapObjectCallback size_func) { - Initialize(space->bottom(), space->top(), size_func); -} - - -HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start) { - Initialize(start, space->top(), NULL); -} - - -HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start, - HeapObjectCallback size_func) { - Initialize(start, space->top(), size_func); -} - - -void HeapObjectIterator::Initialize(Address cur, Address end, - HeapObjectCallback size_f) { - cur_addr_ = cur; - end_addr_ = end; - end_page_ = Page::FromAllocationTop(end); - size_func_ = size_f; - Page* p = Page::FromAllocationTop(cur_addr_); - cur_limit_ = (p == end_page_) ? end_addr_ : p->AllocationTop(); - -#ifdef DEBUG - Verify(); -#endif -} - - -bool HeapObjectIterator::HasNextInNextPage() { - if (cur_addr_ == end_addr_) return false; - - Page* cur_page = Page::FromAllocationTop(cur_addr_); - cur_page = cur_page->next_page(); - ASSERT(cur_page->is_valid()); - - cur_addr_ = cur_page->ObjectAreaStart(); - cur_limit_ = (cur_page == end_page_) ? end_addr_ : cur_page->AllocationTop(); - - ASSERT(cur_addr_ < cur_limit_); -#ifdef DEBUG - Verify(); -#endif - return true; -} - - -#ifdef DEBUG -void HeapObjectIterator::Verify() { - Page* p = Page::FromAllocationTop(cur_addr_); - ASSERT(p == Page::FromAllocationTop(cur_limit_)); - ASSERT(p->Offset(cur_addr_) <= p->Offset(cur_limit_)); -} -#endif - - -// ----------------------------------------------------------------------------- -// PageIterator - -PageIterator::PageIterator(PagedSpace* space, Mode mode) : 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; - } -} - - -// ----------------------------------------------------------------------------- -// Page - -#ifdef DEBUG -Page::RSetState Page::rset_state_ = Page::IN_USE; -#endif - -// ----------------------------------------------------------------------------- -// 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 = *allocated; - size_ += alloced; - Counters::memory_allocated.Increment(alloced); - return mem; -} - - -void MemoryAllocator::FreeRawMemory(void* mem, size_t length) { - if (CodeRange::contains(static_cast<Address>(mem))) { - CodeRange::FreeRawMemory(mem, length); - } else { - OS::Free(mem, length); - } - Counters::memory_allocated.Decrement(length); - size_ -= length; - ASSERT(size_ >= 0); -} - - -void* MemoryAllocator::ReserveInitialChunk(const size_t requested) { - ASSERT(initial_chunk_ == NULL); - - initial_chunk_ = new VirtualMemory(requested); - CHECK(initial_chunk_ != NULL); - if (!initial_chunk_->IsReserved()) { - delete initial_chunk_; - initial_chunk_ = NULL; - return NULL; - } - - // We are sure that we have mapped a block of requested addresses. - ASSERT(initial_chunk_->size() == requested); - LOG(NewEvent("InitialChunk", initial_chunk_->address(), requested)); - size_ += requested; - return initial_chunk_->address(); -} - - -static int PagesInChunk(Address start, size_t size) { - // The first page starts on the first page-aligned address from start onward - // and the last page ends on the last page-aligned address before - // start+size. Page::kPageSize is a power of two so we can divide by - // shifting. - return (RoundDown(start + size, Page::kPageSize) - - RoundUp(start, Page::kPageSize)) >> Page::kPageSizeBits; -} - - -Page* MemoryAllocator::AllocatePages(int requested_pages, int* allocated_pages, - PagedSpace* owner) { - if (requested_pages <= 0) return Page::FromAddress(NULL); - size_t chunk_size = requested_pages * Page::kPageSize; - - // There is not enough space to guarantee the desired number pages can be - // allocated. - if (size_ + static_cast<int>(chunk_size) > capacity_) { - // Request as many pages as we can. - chunk_size = capacity_ - size_; - requested_pages = chunk_size >> Page::kPageSizeBits; - - if (requested_pages <= 0) return Page::FromAddress(NULL); - } - void* chunk = AllocateRawMemory(chunk_size, &chunk_size, owner->executable()); - if (chunk == NULL) return Page::FromAddress(NULL); - LOG(NewEvent("PagedChunk", chunk, chunk_size)); - - *allocated_pages = PagesInChunk(static_cast<Address>(chunk), chunk_size); - if (*allocated_pages == 0) { - FreeRawMemory(chunk, chunk_size); - LOG(DeleteEvent("PagedChunk", chunk)); - return Page::FromAddress(NULL); - } - - int chunk_id = Pop(); - chunks_[chunk_id].init(static_cast<Address>(chunk), chunk_size, owner); - - return InitializePagesInChunk(chunk_id, *allocated_pages, owner); -} - - -Page* MemoryAllocator::CommitPages(Address start, size_t size, - PagedSpace* owner, int* num_pages) { - ASSERT(start != NULL); - *num_pages = PagesInChunk(start, size); - ASSERT(*num_pages > 0); - ASSERT(initial_chunk_ != NULL); - ASSERT(InInitialChunk(start)); - ASSERT(InInitialChunk(start + size - 1)); - if (!initial_chunk_->Commit(start, size, owner->executable() == EXECUTABLE)) { - return Page::FromAddress(NULL); - } - Counters::memory_allocated.Increment(size); - - // So long as we correctly overestimated the number of chunks we should not - // run out of chunk ids. - CHECK(!OutOfChunkIds()); - int chunk_id = Pop(); - chunks_[chunk_id].init(start, size, owner); - return InitializePagesInChunk(chunk_id, *num_pages, owner); -} - - -bool MemoryAllocator::CommitBlock(Address start, - size_t size, - Executability executable) { - ASSERT(start != NULL); - ASSERT(size > 0); - ASSERT(initial_chunk_ != NULL); - ASSERT(InInitialChunk(start)); - ASSERT(InInitialChunk(start + size - 1)); - - if (!initial_chunk_->Commit(start, size, executable)) return false; - Counters::memory_allocated.Increment(size); - return true; -} - -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(size); - return true; -} - -Page* MemoryAllocator::InitializePagesInChunk(int chunk_id, int pages_in_chunk, - PagedSpace* owner) { - ASSERT(IsValidChunk(chunk_id)); - ASSERT(pages_in_chunk > 0); - - Address chunk_start = chunks_[chunk_id].address(); - - Address low = RoundUp(chunk_start, Page::kPageSize); - -#ifdef DEBUG - size_t chunk_size = chunks_[chunk_id].size(); - Address high = RoundDown(chunk_start + chunk_size, Page::kPageSize); - ASSERT(pages_in_chunk <= - ((OffsetFrom(high) - OffsetFrom(low)) / Page::kPageSize)); -#endif - - Address page_addr = low; - for (int i = 0; i < pages_in_chunk; i++) { - Page* p = Page::FromAddress(page_addr); - p->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id; - p->is_normal_page = 1; - page_addr += Page::kPageSize; - } - - // Set the next page of the last page to 0. - Page* last_page = Page::FromAddress(page_addr - Page::kPageSize); - last_page->opaque_header = OffsetFrom(0) | chunk_id; - - return Page::FromAddress(low); -} - - -Page* MemoryAllocator::FreePages(Page* p) { - if (!p->is_valid()) return p; - - // Find the first page in the same chunk as 'p' - Page* first_page = FindFirstPageInSameChunk(p); - Page* page_to_return = Page::FromAddress(NULL); - - if (p != first_page) { - // Find the last page in the same chunk as 'prev'. - Page* last_page = FindLastPageInSameChunk(p); - first_page = GetNextPage(last_page); // first page in next chunk - - // set the next_page of last_page to NULL - SetNextPage(last_page, Page::FromAddress(NULL)); - page_to_return = p; // return 'p' when exiting - } - - while (first_page->is_valid()) { - int chunk_id = GetChunkId(first_page); - ASSERT(IsValidChunk(chunk_id)); - - // Find the first page of the next chunk before deleting this chunk. - first_page = GetNextPage(FindLastPageInSameChunk(first_page)); - - // Free the current chunk. - DeleteChunk(chunk_id); - } - - return page_to_return; -} - - -void MemoryAllocator::DeleteChunk(int chunk_id) { - ASSERT(IsValidChunk(chunk_id)); - - ChunkInfo& c = chunks_[chunk_id]; - - // We cannot free a chunk contained in the initial chunk because it was not - // allocated with AllocateRawMemory. Instead we uncommit the virtual - // memory. - if (InInitialChunk(c.address())) { - // TODO(1240712): VirtualMemory::Uncommit has a return value which - // is ignored here. - initial_chunk_->Uncommit(c.address(), c.size()); - Counters::memory_allocated.Decrement(c.size()); - } else { - LOG(DeleteEvent("PagedChunk", c.address())); - FreeRawMemory(c.address(), c.size()); - } - c.init(NULL, 0, NULL); - Push(chunk_id); -} - - -Page* MemoryAllocator::FindFirstPageInSameChunk(Page* p) { - int chunk_id = GetChunkId(p); - ASSERT(IsValidChunk(chunk_id)); - - Address low = RoundUp(chunks_[chunk_id].address(), Page::kPageSize); - return Page::FromAddress(low); -} - - -Page* MemoryAllocator::FindLastPageInSameChunk(Page* p) { - int chunk_id = GetChunkId(p); - ASSERT(IsValidChunk(chunk_id)); - - Address chunk_start = chunks_[chunk_id].address(); - size_t chunk_size = chunks_[chunk_id].size(); - - Address high = RoundDown(chunk_start + chunk_size, Page::kPageSize); - ASSERT(chunk_start <= p->address() && p->address() < high); - - return Page::FromAddress(high - Page::kPageSize); -} - - -#ifdef DEBUG -void MemoryAllocator::ReportStatistics() { - float pct = static_cast<float>(capacity_ - size_) / capacity_; - PrintF(" capacity: %d, used: %d, available: %%%d\n\n", - capacity_, size_, static_cast<int>(pct*100)); -} -#endif - - -// ----------------------------------------------------------------------------- -// PagedSpace implementation - -PagedSpace::PagedSpace(int max_capacity, - AllocationSpace id, - Executability executable) - : Space(id, executable) { - max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize) - * Page::kObjectAreaSize; - accounting_stats_.Clear(); - - allocation_info_.top = NULL; - allocation_info_.limit = NULL; - - mc_forwarding_info_.top = NULL; - mc_forwarding_info_.limit = NULL; -} - - -bool PagedSpace::Setup(Address start, size_t size) { - if (HasBeenSetup()) return false; - - int num_pages = 0; - // Try to use the virtual memory range passed to us. If it is too small to - // contain at least one page, ignore it and allocate instead. - int pages_in_chunk = PagesInChunk(start, size); - if (pages_in_chunk > 0) { - first_page_ = MemoryAllocator::CommitPages(RoundUp(start, Page::kPageSize), - Page::kPageSize * pages_in_chunk, - this, &num_pages); - } else { - int requested_pages = Min(MemoryAllocator::kPagesPerChunk, - max_capacity_ / Page::kObjectAreaSize); - first_page_ = - MemoryAllocator::AllocatePages(requested_pages, &num_pages, this); - if (!first_page_->is_valid()) return false; - } - - // We are sure that the first page is valid and that we have at least one - // page. - ASSERT(first_page_->is_valid()); - ASSERT(num_pages > 0); - accounting_stats_.ExpandSpace(num_pages * Page::kObjectAreaSize); - ASSERT(Capacity() <= max_capacity_); - - // Sequentially initialize remembered sets 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->ClearRSet(); - last_page_ = p; - } - - // Use first_page_ for allocation. - SetAllocationInfo(&allocation_info_, first_page_); - - return true; -} - - -bool PagedSpace::HasBeenSetup() { - return (Capacity() > 0); -} - - -void PagedSpace::TearDown() { - first_page_ = MemoryAllocator::FreePages(first_page_); - ASSERT(!first_page_->is_valid()); - - accounting_stats_.Clear(); -} - - -#ifdef ENABLE_HEAP_PROTECTION - -void PagedSpace::Protect() { - Page* page = first_page_; - while (page->is_valid()) { - MemoryAllocator::ProtectChunkFromPage(page); - page = MemoryAllocator::FindLastPageInSameChunk(page)->next_page(); - } -} - - -void PagedSpace::Unprotect() { - Page* page = first_page_; - while (page->is_valid()) { - MemoryAllocator::UnprotectChunkFromPage(page); - page = MemoryAllocator::FindLastPageInSameChunk(page)->next_page(); - } -} - -#endif - - -void PagedSpace::ClearRSet() { - PageIterator it(this, PageIterator::ALL_PAGES); - while (it.has_next()) { - it.next()->ClearRSet(); - } -} - - -Object* PagedSpace::FindObject(Address addr) { - // Note: this function can only be called before or after mark-compact GC - // because it accesses map pointers. - ASSERT(!MarkCompactCollector::in_use()); - - if (!Contains(addr)) return Failure::Exception(); - - Page* p = Page::FromAddress(addr); - ASSERT(IsUsed(p)); - Address cur = p->ObjectAreaStart(); - Address end = p->AllocationTop(); - while (cur < end) { - HeapObject* obj = HeapObject::FromAddress(cur); - Address next = cur + obj->Size(); - if ((cur <= addr) && (addr < next)) return obj; - cur = next; - } - - UNREACHABLE(); - return Failure::Exception(); -} - - -bool PagedSpace::IsUsed(Page* page) { - PageIterator it(this, PageIterator::PAGES_IN_USE); - while (it.has_next()) { - if (page == it.next()) return true; - } - return false; -} - - -void PagedSpace::SetAllocationInfo(AllocationInfo* alloc_info, Page* p) { - alloc_info->top = p->ObjectAreaStart(); - alloc_info->limit = p->ObjectAreaEnd(); - ASSERT(alloc_info->VerifyPagedAllocation()); -} - - -void PagedSpace::MCResetRelocationInfo() { - // Set page indexes. - int i = 0; - PageIterator it(this, PageIterator::ALL_PAGES); - while (it.has_next()) { - Page* p = it.next(); - p->mc_page_index = i++; - } - - // Set mc_forwarding_info_ to the first page in the space. - SetAllocationInfo(&mc_forwarding_info_, first_page_); - // All the bytes in the space are 'available'. We will rediscover - // allocated and wasted bytes during GC. - accounting_stats_.Reset(); -} - - -int PagedSpace::MCSpaceOffsetForAddress(Address addr) { -#ifdef DEBUG - // The Contains function considers the address at the beginning of a - // page in the page, MCSpaceOffsetForAddress considers it is in the - // previous page. - if (Page::IsAlignedToPageSize(addr)) { - ASSERT(Contains(addr - kPointerSize)); - } else { - ASSERT(Contains(addr)); - } -#endif - - // If addr is at the end of a page, it belongs to previous page - Page* p = Page::IsAlignedToPageSize(addr) - ? Page::FromAllocationTop(addr) - : Page::FromAddress(addr); - int index = p->mc_page_index; - return (index * Page::kPageSize) + p->Offset(addr); -} - - -// Slow case for reallocating and promoting objects during a compacting -// collection. This function is not space-specific. -HeapObject* PagedSpace::SlowMCAllocateRaw(int size_in_bytes) { - Page* current_page = TopPageOf(mc_forwarding_info_); - if (!current_page->next_page()->is_valid()) { - if (!Expand(current_page)) { - return NULL; - } - } - - // There are surely more pages in the space now. - ASSERT(current_page->next_page()->is_valid()); - // We do not add the top of page block for current page to the space's - // free list---the block may contain live objects so we cannot write - // bookkeeping information to it. Instead, we will recover top of page - // blocks when we move objects to their new locations. - // - // We do however write the allocation pointer to the page. The encoding - // of forwarding addresses is as an offset in terms of live bytes, so we - // need quick access to the allocation top of each page to decode - // forwarding addresses. - current_page->mc_relocation_top = mc_forwarding_info_.top; - SetAllocationInfo(&mc_forwarding_info_, current_page->next_page()); - return AllocateLinearly(&mc_forwarding_info_, size_in_bytes); -} - - -bool PagedSpace::Expand(Page* last_page) { - ASSERT(max_capacity_ % Page::kObjectAreaSize == 0); - ASSERT(Capacity() % Page::kObjectAreaSize == 0); - - if (Capacity() == max_capacity_) return false; - - ASSERT(Capacity() < max_capacity_); - // Last page must be valid and its next page is invalid. - ASSERT(last_page->is_valid() && !last_page->next_page()->is_valid()); - - int available_pages = (max_capacity_ - Capacity()) / Page::kObjectAreaSize; - if (available_pages <= 0) return false; - - int desired_pages = Min(available_pages, MemoryAllocator::kPagesPerChunk); - Page* p = MemoryAllocator::AllocatePages(desired_pages, &desired_pages, this); - if (!p->is_valid()) return false; - - accounting_stats_.ExpandSpace(desired_pages * Page::kObjectAreaSize); - ASSERT(Capacity() <= max_capacity_); - - MemoryAllocator::SetNextPage(last_page, p); - - // Sequentially clear remembered set of new pages and and cache the - // new last page in the space. - while (p->is_valid()) { - p->ClearRSet(); - 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() { - // 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 { - // Unless this is the last page in the space containing allocated - // objects, the allocation top should be at a constant offset from the - // object area end. - Address top = current_page->AllocationTop(); - if (current_page == top_page) { - ASSERT(top == allocation_info_.top); - // The next page will be above the allocation top. - above_allocation_top = true; - } else { - ASSERT(top == current_page->ObjectAreaEnd() - page_extra_); - } - - // 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 their remembered set bits set if required as determined - // by the visitor. - int size = object->Size(); - object->IterateBody(map->instance_type(), size, visitor); - - current += size; - } - - // The allocation pointer should not be in the middle of an object. - ASSERT(current == top); - } - - current_page = current_page->next_page(); - } -} -#endif - - -// ----------------------------------------------------------------------------- -// NewSpace implementation - - -bool NewSpace::Setup(Address start, int size) { - // Setup new space based on the preallocated memory block defined by - // start and size. The provided space is divided into two semi-spaces. - // To support fast containment testing in the new space, the size of - // this chunk must be a power of two and it must be aligned to its size. - int initial_semispace_capacity = Heap::InitialSemiSpaceSize(); - int maximum_semispace_capacity = Heap::SemiSpaceSize(); - - ASSERT(initial_semispace_capacity <= maximum_semispace_capacity); - ASSERT(IsPowerOf2(maximum_semispace_capacity)); - - // Allocate and setup the histogram arrays if necessary. -#if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) - allocated_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1); - promoted_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1); - -#define SET_NAME(name) allocated_histogram_[name].set_name(#name); \ - promoted_histogram_[name].set_name(#name); - INSTANCE_TYPE_LIST(SET_NAME) -#undef SET_NAME -#endif - - ASSERT(size == 2 * maximum_semispace_capacity); - 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_ | kHeapObjectTag; - object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag; - - allocation_info_.top = to_space_.low(); - allocation_info_.limit = to_space_.high(); - mc_forwarding_info_.top = NULL; - mc_forwarding_info_.limit = NULL; - - 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, 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_ | kHeapObjectTag; - 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_, 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]; - -#define CASE(name) \ - case Code::name: table[Code::name] = #name; \ - break - - for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) { - switch (static_cast<Code::Kind>(i)) { - CASE(FUNCTION); - CASE(STUB); - CASE(BUILTIN); - CASE(LOAD_IC); - CASE(KEYED_LOAD_IC); - CASE(STORE_IC); - CASE(KEYED_STORE_IC); - CASE(CALL_IC); - } - } - -#undef CASE - - PrintF("\n Code kind histograms: \n"); - for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) { - if (code_kind_statistics[i] > 0) { - PrintF(" %-20s: %10d bytes\n", table[i], code_kind_statistics[i]); - } - } - PrintF("\n"); -} - - -static int CollectHistogramInfo(HeapObject* obj) { - InstanceType type = obj->map()->instance_type(); - ASSERT(0 <= type && type <= LAST_TYPE); - ASSERT(heap_histograms[type].name() != NULL); - heap_histograms[type].increment_number(1); - heap_histograms[type].increment_bytes(obj->Size()); - - if (FLAG_collect_heap_spill_statistics && obj->IsJSObject()) { - JSObject::cast(obj)->IncrementSpillStatistics(&js_spill_information); - } - - return obj->Size(); -} - - -static void ReportHistogram(bool print_spill) { - PrintF("\n Object Histogram:\n"); - for (int i = 0; i <= LAST_TYPE; i++) { - if (heap_histograms[i].number() > 0) { - PrintF(" %-33s%10d (%10d bytes)\n", - heap_histograms[i].name(), - heap_histograms[i].number(), - heap_histograms[i].bytes()); - } - } - PrintF("\n"); - - // Summarize string types. - int string_number = 0; - int string_bytes = 0; -#define INCREMENT(type, size, name, 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(" %-33s%10d (%10d bytes)\n\n", "STRING_TYPE", string_number, - string_bytes); - } - - if (FLAG_collect_heap_spill_statistics && print_spill) { - js_spill_information.Print(); - } -} -#endif // DEBUG - - -// Support for statistics gathering for --heap-stats and --log-gc. -#if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) -void NewSpace::ClearHistograms() { - for (int i = 0; i <= LAST_TYPE; i++) { - allocated_histogram_[i].clear(); - promoted_histogram_[i].clear(); - } -} - -// Because the copying collector does not touch garbage objects, we iterate -// the new space before a collection to get a histogram of allocated objects. -// This only happens (1) when compiled with DEBUG and the --heap-stats flag is -// set, or when compiled with ENABLE_LOGGING_AND_PROFILING and the --log-gc -// flag is set. -void NewSpace::CollectStatistics() { - ClearHistograms(); - SemiSpaceIterator it(this); - while (it.has_next()) RecordAllocation(it.next()); -} - - -#ifdef ENABLE_LOGGING_AND_PROFILING -static void DoReportStatistics(HistogramInfo* info, const char* description) { - LOG(HeapSampleBeginEvent("NewSpace", description)); - // Lump all the string types together. - int string_number = 0; - int string_bytes = 0; -#define INCREMENT(type, size, name, 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(" %-33s%10d (%10d bytes)\n", - allocated_histogram_[i].name(), - allocated_histogram_[i].number(), - allocated_histogram_[i].bytes()); - } - } - PrintF("\n"); - } -#endif // DEBUG - -#ifdef ENABLE_LOGGING_AND_PROFILING - if (FLAG_log_gc) { - DoReportStatistics(allocated_histogram_, "allocated"); - DoReportStatistics(promoted_histogram_, "promoted"); - } -#endif // ENABLE_LOGGING_AND_PROFILING -} - - -void NewSpace::RecordAllocation(HeapObject* obj) { - InstanceType type = obj->map()->instance_type(); - ASSERT(0 <= type && type <= LAST_TYPE); - allocated_histogram_[type].increment_number(1); - allocated_histogram_[type].increment_bytes(obj->Size()); -} - - -void NewSpace::RecordPromotion(HeapObject* obj) { - InstanceType type = obj->map()->instance_type(); - ASSERT(0 <= type && type <= LAST_TYPE); - promoted_histogram_[type].increment_number(1); - promoted_histogram_[type].increment_bytes(obj->Size()); -} -#endif // defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) - - -// ----------------------------------------------------------------------------- -// Free lists for old object spaces implementation - -void FreeListNode::set_size(int size_in_bytes) { - ASSERT(size_in_bytes > 0); - ASSERT(IsAligned(size_in_bytes, kPointerSize)); - - // We write a map and possibly size information to the block. If the block - // is big enough to be a ByteArray with at least one extra word (the next - // pointer), we set its map to be the byte array map and its size to an - // appropriate array length for the desired size from HeapObject::Size(). - // If the block is too small (eg, one or two words), to hold both a size - // field and a next pointer, we give it a filler map that gives it the - // correct size. - if (size_in_bytes > ByteArray::kAlignedSize) { - set_map(Heap::raw_unchecked_byte_array_map()); - ByteArray::cast(this)->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(); - } - ASSERT(Size() == size_in_bytes); -} - - -Address FreeListNode::next() { - ASSERT(map() == Heap::raw_unchecked_byte_array_map() || - map() == Heap::raw_unchecked_two_pointer_filler_map()); - 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(map() == Heap::raw_unchecked_byte_array_map() || - map() == Heap::raw_unchecked_two_pointer_filler_map()); - 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 - for (int i = 0; i < size_in_bytes; i += kPointerSize) { - Memory::Address_at(start + i) = kZapValue; - } -#endif - FreeListNode* node = FreeListNode::FromAddress(start); - node->set_size(size_in_bytes); - - // 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_ = NULL; -} - - -void FixedSizeFreeList::Free(Address start) { -#ifdef DEBUG - for (int i = 0; i < object_size_; i += kPointerSize) { - Memory::Address_at(start + i) = kZapValue; - } -#endif - ASSERT(!FLAG_always_compact); // We only use the freelists with mark-sweep. - FreeListNode* node = FreeListNode::FromAddress(start); - node->set_size(object_size_); - node->set_next(head_); - head_ = 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) { - 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 += p->mc_relocation_top - p->ObjectAreaStart(); - if (it.has_next()) { - // Free the space at the top of the page. We cannot use - // p->mc_relocation_top after the call to Free (because Free will clear - // remembered set bits). - int extra_size = p->ObjectAreaEnd() - p->mc_relocation_top; - if (extra_size > 0) { - int wasted_bytes = free_list_.Free(p->mc_relocation_top, extra_size); - // The bytes we have just "freed" to add to the free list were - // already accounted as available. - accounting_stats_.WasteBytes(wasted_bytes); - } - } - } - - // Make sure the computed size - based on the used portion of the pages in - // use - matches the size obtained while computing forwarding addresses. - ASSERT(computed_size == Size()); -} - - -// Slow case for normal allocation. Try in order: (1) allocate in the next -// page in the space, (2) allocate off the space's free list, (3) expand the -// space, (4) fail. -HeapObject* OldSpace::SlowAllocateRaw(int size_in_bytes) { - // Linear allocation in this space has failed. If there is another page - // in the space, move to that page and allocate there. This allocation - // should succeed (size_in_bytes should not be greater than a page's - // object area size). - Page* current_page = TopPageOf(allocation_info_); - if (current_page->next_page()->is_valid()) { - return AllocateInNextPage(current_page, size_in_bytes); - } - - // There is no next page in this space. Try free list allocation. - int wasted_bytes; - Object* result = free_list_.Allocate(size_in_bytes, &wasted_bytes); - accounting_stats_.WasteBytes(wasted_bytes); - if (!result->IsFailure()) { - accounting_stats_.AllocateBytes(size_in_bytes); - return HeapObject::cast(result); - } - - // Free list allocation failed and there is no next page. Fail if we have - // hit the old generation size limit that should cause a garbage - // collection. - if (!Heap::always_allocate() && Heap::OldGenerationAllocationLimitReached()) { - return NULL; - } - - // Try to expand the space and allocate in the new next page. - ASSERT(!current_page->next_page()->is_valid()); - if (Expand(current_page)) { - return AllocateInNextPage(current_page, size_in_bytes); - } - - // Finally, fail. - return NULL; -} - - -// Add the block at the top of the page to the space's free list, set the -// allocation info to the next page (assumed to be one), and allocate -// linearly there. -HeapObject* OldSpace::AllocateInNextPage(Page* current_page, - int size_in_bytes) { - ASSERT(current_page->next_page()->is_valid()); - // Add the block at the top of this page to the free list. - int free_size = current_page->ObjectAreaEnd() - allocation_info_.top; - if (free_size > 0) { - int wasted_bytes = free_list_.Free(allocation_info_.top, free_size); - accounting_stats_.WasteBytes(wasted_bytes); - } - SetAllocationInfo(&allocation_info_, current_page->next_page()); - return AllocateLinearly(&allocation_info_, size_in_bytes); -} - - -#ifdef DEBUG -struct CommentStatistic { - const char* comment; - int size; - int count; - void Clear() { - comment = NULL; - size = 0; - count = 0; - } -}; - - -// must be small, since an iteration is used for lookup -const int kMaxComments = 64; -static CommentStatistic comments_statistics[kMaxComments+1]; - - -void PagedSpace::ReportCodeStatistics() { - ReportCodeKindStatistics(); - PrintF("Code comment statistics (\" [ comment-txt : size/ " - "count (average)\"):\n"); - for (int i = 0; i <= kMaxComments; i++) { - const CommentStatistic& cs = comments_statistics[i]; - if (cs.size > 0) { - PrintF(" %-30s: %10d/%6d (%d)\n", cs.comment, cs.size, cs.count, - cs.size/cs.count); - } - } - PrintF("\n"); -} - - -void PagedSpace::ResetCodeStatistics() { - ClearCodeKindStatistics(); - for (int i = 0; i < kMaxComments; i++) comments_statistics[i].Clear(); - comments_statistics[kMaxComments].comment = "Unknown"; - comments_statistics[kMaxComments].size = 0; - comments_statistics[kMaxComments].count = 0; -} - - -// Adds comment to 'comment_statistics' table. Performance OK sa long as -// 'kMaxComments' is small -static void EnterComment(const char* comment, int delta) { - // Do not count empty comments - if (delta <= 0) return; - CommentStatistic* cs = &comments_statistics[kMaxComments]; - // Search for a free or matching entry in 'comments_statistics': 'cs' - // points to result. - for (int i = 0; i < kMaxComments; i++) { - if (comments_statistics[i].comment == NULL) { - cs = &comments_statistics[i]; - cs->comment = comment; - break; - } else if (strcmp(comments_statistics[i].comment, comment) == 0) { - cs = &comments_statistics[i]; - break; - } - } - // Update entry for 'comment' - cs->size += delta; - cs->count += 1; -} - - -// Call for each nested comment start (start marked with '[ xxx', end marked -// with ']'. RelocIterator 'it' must point to a comment reloc info. -static void CollectCommentStatistics(RelocIterator* it) { - ASSERT(!it->done()); - ASSERT(it->rinfo()->rmode() == RelocInfo::COMMENT); - const char* tmp = reinterpret_cast<const char*>(it->rinfo()->data()); - if (tmp[0] != '[') { - // Not a nested comment; skip - return; - } - - // Search for end of nested comment or a new nested comment - const char* const comment_txt = - reinterpret_cast<const char*>(it->rinfo()->data()); - const byte* prev_pc = it->rinfo()->pc(); - int flat_delta = 0; - it->next(); - while (true) { - // All nested comments must be terminated properly, and therefore exit - // from loop. - ASSERT(!it->done()); - if (it->rinfo()->rmode() == RelocInfo::COMMENT) { - const char* const txt = - reinterpret_cast<const char*>(it->rinfo()->data()); - flat_delta += it->rinfo()->pc() - prev_pc; - if (txt[0] == ']') break; // End of nested comment - // A new comment - CollectCommentStatistics(it); - // Skip code that was covered with previous comment - prev_pc = it->rinfo()->pc(); - } - it->next(); - } - EnterComment(comment_txt, flat_delta); -} - - -// Collects code size statistics: -// - by code kind -// - by code comment -void PagedSpace::CollectCodeStatistics() { - HeapObjectIterator obj_it(this); - while (obj_it.has_next()) { - HeapObject* obj = obj_it.next(); - if (obj->IsCode()) { - Code* code = Code::cast(obj); - code_kind_statistics[code->kind()] += code->Size(); - RelocIterator it(code); - int delta = 0; - const byte* prev_pc = code->instruction_start(); - while (!it.done()) { - if (it.rinfo()->rmode() == RelocInfo::COMMENT) { - delta += it.rinfo()->pc() - prev_pc; - CollectCommentStatistics(&it); - prev_pc = it.rinfo()->pc(); - } - it.next(); - } - - ASSERT(code->instruction_start() <= prev_pc && - prev_pc <= code->relocation_start()); - delta += code->relocation_start() - prev_pc; - EnterComment("NoComment", delta); - } - } -} - - -void OldSpace::ReportStatistics() { - int pct = Available() * 100 / Capacity(); - PrintF(" capacity: %d, waste: %d, available: %d, %%%d\n", - Capacity(), Waste(), Available(), pct); - - // Report remembered set statistics. - int rset_marked_pointers = 0; - int rset_marked_arrays = 0; - int rset_marked_array_elements = 0; - int cross_gen_pointers = 0; - int cross_gen_array_elements = 0; - - PageIterator page_it(this, PageIterator::PAGES_IN_USE); - while (page_it.has_next()) { - Page* p = page_it.next(); - - for (Address rset_addr = p->RSetStart(); - rset_addr < p->RSetEnd(); - rset_addr += kIntSize) { - int rset = Memory::int_at(rset_addr); - if (rset != 0) { - // Bits were set - int intoff = rset_addr - p->address() - Page::kRSetOffset; - int bitoff = 0; - for (; bitoff < kBitsPerInt; ++bitoff) { - if ((rset & (1 << bitoff)) != 0) { - int bitpos = intoff*kBitsPerByte + bitoff; - Address slot = p->OffsetToAddress(bitpos << kObjectAlignmentBits); - Object** obj = reinterpret_cast<Object**>(slot); - if (*obj == Heap::raw_unchecked_fixed_array_map()) { - rset_marked_arrays++; - FixedArray* fa = FixedArray::cast(HeapObject::FromAddress(slot)); - - rset_marked_array_elements += fa->length(); - // Manually inline FixedArray::IterateBody - Address elm_start = slot + FixedArray::kHeaderSize; - Address elm_stop = elm_start + fa->length() * kPointerSize; - for (Address elm_addr = elm_start; - elm_addr < elm_stop; elm_addr += kPointerSize) { - // Filter non-heap-object pointers - Object** elm_p = reinterpret_cast<Object**>(elm_addr); - if (Heap::InNewSpace(*elm_p)) - cross_gen_array_elements++; - } - } else { - rset_marked_pointers++; - if (Heap::InNewSpace(*obj)) - cross_gen_pointers++; - } - } - } - } - } - } - - pct = rset_marked_pointers == 0 ? - 0 : cross_gen_pointers * 100 / rset_marked_pointers; - PrintF(" rset-marked pointers %d, to-new-space %d (%%%d)\n", - rset_marked_pointers, cross_gen_pointers, pct); - PrintF(" rset_marked arrays %d, ", rset_marked_arrays); - PrintF(" elements %d, ", rset_marked_array_elements); - pct = rset_marked_array_elements == 0 ? 0 - : cross_gen_array_elements * 100 / rset_marked_array_elements; - PrintF(" pointers to new space %d (%%%d)\n", cross_gen_array_elements, pct); - PrintF(" total rset-marked bits %d\n", - (rset_marked_pointers + rset_marked_arrays)); - pct = (rset_marked_pointers + rset_marked_array_elements) == 0 ? 0 - : (cross_gen_pointers + cross_gen_array_elements) * 100 / - (rset_marked_pointers + rset_marked_array_elements); - PrintF(" total rset pointers %d, true cross generation ones %d (%%%d)\n", - (rset_marked_pointers + rset_marked_array_elements), - (cross_gen_pointers + cross_gen_array_elements), - pct); - - ClearHistograms(); - HeapObjectIterator obj_it(this); - while (obj_it.has_next()) { CollectHistogramInfo(obj_it.next()); } - ReportHistogram(true); -} - - -// Dump the range of remembered set words between [start, end) corresponding -// to the pointers starting at object_p. The allocation_top is an object -// pointer which should not be read past. This is important for large object -// pages, where some bits in the remembered set range do not correspond to -// allocated addresses. -static void PrintRSetRange(Address start, Address end, Object** object_p, - Address allocation_top) { - Address rset_address = start; - - // If the range starts on on odd numbered word (eg, for large object extra - // remembered set ranges), print some spaces. - if ((reinterpret_cast<uintptr_t>(start) / kIntSize) % 2 == 1) { - PrintF(" "); - } - - // Loop over all the words in the range. - while (rset_address < end) { - uint32_t rset_word = Memory::uint32_at(rset_address); - int bit_position = 0; - - // Loop over all the bits in the word. - while (bit_position < kBitsPerInt) { - if (object_p == reinterpret_cast<Object**>(allocation_top)) { - // Print a bar at the allocation pointer. - PrintF("|"); - } else if (object_p > reinterpret_cast<Object**>(allocation_top)) { - // Do not dereference object_p past the allocation pointer. - PrintF("#"); - } else if ((rset_word & (1 << bit_position)) == 0) { - // Print a dot for zero bits. - PrintF("."); - } else if (Heap::InNewSpace(*object_p)) { - // Print an X for one bits for pointers to new space. - PrintF("X"); - } else { - // Print a circle for one bits for pointers to old space. - PrintF("o"); - } - - // Print a space after every 8th bit except the last. - if (bit_position % 8 == 7 && bit_position != (kBitsPerInt - 1)) { - PrintF(" "); - } - - // Advance to next bit. - bit_position++; - object_p++; - } - - // Print a newline after every odd numbered word, otherwise a space. - if ((reinterpret_cast<uintptr_t>(rset_address) / kIntSize) % 2 == 1) { - PrintF("\n"); - } else { - PrintF(" "); - } - - // Advance to next remembered set word. - rset_address += kIntSize; - } -} - - -void PagedSpace::DoPrintRSet(const char* space_name) { - PageIterator it(this, PageIterator::PAGES_IN_USE); - while (it.has_next()) { - Page* p = it.next(); - PrintF("%s page 0x%x:\n", space_name, p); - PrintRSetRange(p->RSetStart(), p->RSetEnd(), - reinterpret_cast<Object**>(p->ObjectAreaStart()), - p->AllocationTop()); - PrintF("\n"); - } -} - - -void OldSpace::PrintRSet() { DoPrintRSet("old"); } -#endif - -// ----------------------------------------------------------------------------- -// FixedSpace implementation - -void FixedSpace::PrepareForMarkCompact(bool 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 += page_top - page->ObjectAreaStart(); - if (it.has_next()) { - accounting_stats_.WasteBytes(page->ObjectAreaEnd() - page_top); - } - } - - // Make sure the computed size - based on the used portion of the - // pages in use - matches the size we adjust during allocation. - ASSERT(computed_size == Size()); -} - - -// Slow case for normal allocation. Try in order: (1) allocate in the next -// page in the space, (2) allocate off the space's free list, (3) expand the -// space, (4) fail. -HeapObject* 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. - // The fixed space free list implicitly assumes that all free blocks - // are of the fixed size. - if (size_in_bytes == object_size_in_bytes_) { - Object* result = free_list_.Allocate(); - if (!result->IsFailure()) { - accounting_stats_.AllocateBytes(size_in_bytes); - return HeapObject::cast(result); - } - } - - // Free list allocation failed and there is no next page. Fail if we have - // hit the old generation size limit that should cause a garbage - // collection. - if (!Heap::always_allocate() && Heap::OldGenerationAllocationLimitReached()) { - return NULL; - } - - // Try to expand the space and allocate in the new next page. - ASSERT(!current_page->next_page()->is_valid()); - if (Expand(current_page)) { - return AllocateInNextPage(current_page, size_in_bytes); - } - - // Finally, fail. - return NULL; -} - - -// Move to the next page (there is assumed to be one) and allocate there. -// The top of page block is always wasted, because it is too small to hold a -// map. -HeapObject* FixedSpace::AllocateInNextPage(Page* current_page, - int size_in_bytes) { - ASSERT(current_page->next_page()->is_valid()); - ASSERT(current_page->ObjectAreaEnd() - allocation_info_.top == page_extra_); - ASSERT_EQ(object_size_in_bytes_, size_in_bytes); - accounting_stats_.WasteBytes(page_extra_); - SetAllocationInfo(&allocation_info_, current_page->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); - - // Report remembered set statistics. - int rset_marked_pointers = 0; - int cross_gen_pointers = 0; - - PageIterator page_it(this, PageIterator::PAGES_IN_USE); - while (page_it.has_next()) { - Page* p = page_it.next(); - - for (Address rset_addr = p->RSetStart(); - rset_addr < p->RSetEnd(); - rset_addr += kIntSize) { - int rset = Memory::int_at(rset_addr); - if (rset != 0) { - // Bits were set - int intoff = rset_addr - p->address() - Page::kRSetOffset; - int bitoff = 0; - for (; bitoff < kBitsPerInt; ++bitoff) { - if ((rset & (1 << bitoff)) != 0) { - int bitpos = intoff*kBitsPerByte + bitoff; - Address slot = p->OffsetToAddress(bitpos << kObjectAlignmentBits); - Object** obj = reinterpret_cast<Object**>(slot); - rset_marked_pointers++; - if (Heap::InNewSpace(*obj)) - cross_gen_pointers++; - } - } - } - } - } - - pct = rset_marked_pointers == 0 ? - 0 : cross_gen_pointers * 100 / rset_marked_pointers; - PrintF(" rset-marked pointers %d, to-new-space %d (%%%d)\n", - rset_marked_pointers, cross_gen_pointers, pct); - - ClearHistograms(); - HeapObjectIterator obj_it(this); - while (obj_it.has_next()) { CollectHistogramInfo(obj_it.next()); } - ReportHistogram(false); -} - - -void FixedSpace::PrintRSet() { DoPrintRSet(name_); } -#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() { - ASSERT(has_next()); - HeapObject* object = current_->GetObject(); - current_ = current_->next(); - return object; -} - - -// ----------------------------------------------------------------------------- -// LargeObjectChunk - -LargeObjectChunk* LargeObjectChunk::New(int size_in_bytes, - size_t* chunk_size, - Executability executable) { - size_t requested = ChunkSizeFor(size_in_bytes); - void* mem = MemoryAllocator::AllocateRawMemory(requested, - chunk_size, - executable); - if (mem == NULL) return NULL; - LOG(NewEvent("LargeObjectChunk", mem, *chunk_size)); - if (*chunk_size < requested) { - MemoryAllocator::FreeRawMemory(mem, *chunk_size); - LOG(DeleteEvent("LargeObjectChunk", mem)); - return NULL; - } - return reinterpret_cast<LargeObjectChunk*>(mem); -} - - -int LargeObjectChunk::ChunkSizeFor(int size_in_bytes) { - int os_alignment = OS::AllocateAlignment(); - if (os_alignment < Page::kPageSize) - size_in_bytes += (Page::kPageSize - os_alignment); - return size_in_bytes + Page::kObjectStartOffset; -} - -// ----------------------------------------------------------------------------- -// LargeObjectSpace - -LargeObjectSpace::LargeObjectSpace(AllocationSpace id) - : Space(id, NOT_EXECUTABLE), // Managed on a per-allocation basis - first_chunk_(NULL), - size_(0), - page_count_(0) {} - - -bool LargeObjectSpace::Setup() { - first_chunk_ = NULL; - size_ = 0; - page_count_ = 0; - return true; -} - - -void LargeObjectSpace::TearDown() { - while (first_chunk_ != NULL) { - LargeObjectChunk* chunk = first_chunk_; - first_chunk_ = first_chunk_->next(); - LOG(DeleteEvent("LargeObjectChunk", chunk->address())); - MemoryAllocator::FreeRawMemory(chunk->address(), chunk->size()); - } - - size_ = 0; - page_count_ = 0; -} - - -#ifdef ENABLE_HEAP_PROTECTION - -void LargeObjectSpace::Protect() { - LargeObjectChunk* chunk = first_chunk_; - while (chunk != NULL) { - MemoryAllocator::Protect(chunk->address(), chunk->size()); - chunk = chunk->next(); - } -} - - -void LargeObjectSpace::Unprotect() { - LargeObjectChunk* chunk = first_chunk_; - while (chunk != NULL) { - bool is_code = chunk->GetObject()->IsCode(); - MemoryAllocator::Unprotect(chunk->address(), chunk->size(), - is_code ? EXECUTABLE : NOT_EXECUTABLE); - chunk = chunk->next(); - } -} - -#endif - - -Object* LargeObjectSpace::AllocateRawInternal(int requested_size, - int object_size, - Executability executable) { - ASSERT(0 < object_size && object_size <= requested_size); - - // Check if we want to force a GC before growing the old space further. - // If so, fail the allocation. - if (!Heap::always_allocate() && Heap::OldGenerationAllocationLimitReached()) { - return Failure::RetryAfterGC(requested_size, identity()); - } - - size_t chunk_size; - LargeObjectChunk* chunk = - LargeObjectChunk::New(requested_size, &chunk_size, executable); - if (chunk == NULL) { - return Failure::RetryAfterGC(requested_size, identity()); - } - - size_ += chunk_size; - page_count_++; - chunk->set_next(first_chunk_); - chunk->set_size(chunk_size); - first_chunk_ = chunk; - - // Set the object address and size in the page header and clear its - // remembered set. - Page* page = Page::FromAddress(RoundUp(chunk->address(), Page::kPageSize)); - Address object_address = page->ObjectAreaStart(); - // Clear the low order bit of the second word in the page to flag it as a - // large object page. If the chunk_size happened to be written there, its - // low order bit should already be clear. - ASSERT((chunk_size & 0x1) == 0); - page->is_normal_page &= ~0x1; - page->ClearRSet(); - int extra_bytes = requested_size - object_size; - if (extra_bytes > 0) { - // The extra memory for the remembered set should be cleared. - memset(object_address + object_size, 0, extra_bytes); - } - - return HeapObject::FromAddress(object_address); -} - - -Object* LargeObjectSpace::AllocateRawCode(int size_in_bytes) { - ASSERT(0 < size_in_bytes); - return AllocateRawInternal(size_in_bytes, - size_in_bytes, - EXECUTABLE); -} - - -Object* LargeObjectSpace::AllocateRawFixedArray(int size_in_bytes) { - ASSERT(0 < size_in_bytes); - int extra_rset_bytes = ExtraRSetBytesFor(size_in_bytes); - return AllocateRawInternal(size_in_bytes + extra_rset_bytes, - size_in_bytes, - NOT_EXECUTABLE); -} - - -Object* LargeObjectSpace::AllocateRaw(int size_in_bytes) { - ASSERT(0 < size_in_bytes); - return AllocateRawInternal(size_in_bytes, - size_in_bytes, - NOT_EXECUTABLE); -} - - -// GC support -Object* LargeObjectSpace::FindObject(Address a) { - for (LargeObjectChunk* chunk = first_chunk_; - chunk != NULL; - chunk = chunk->next()) { - Address chunk_address = chunk->address(); - if (chunk_address <= a && a < chunk_address + chunk->size()) { - return chunk->GetObject(); - } - } - return Failure::Exception(); -} - - -void LargeObjectSpace::ClearRSet() { - ASSERT(Page::is_rset_in_use()); - - LargeObjectIterator it(this); - while (it.has_next()) { - HeapObject* object = it.next(); - // We only have code, sequential strings, or fixed arrays in large - // object space, and only fixed arrays need remembered set support. - if (object->IsFixedArray()) { - // Clear the normal remembered set region of the page; - Page* page = Page::FromAddress(object->address()); - page->ClearRSet(); - - // Clear the extra remembered set. - int size = object->Size(); - int extra_rset_bytes = ExtraRSetBytesFor(size); - memset(object->address() + size, 0, extra_rset_bytes); - } - } -} - - -void LargeObjectSpace::IterateRSet(ObjectSlotCallback copy_object_func) { - ASSERT(Page::is_rset_in_use()); - - static void* lo_rset_histogram = StatsTable::CreateHistogram( - "V8.RSetLO", - 0, - // Keeping this histogram's buckets the same as the paged space histogram. - Page::kObjectAreaSize / kPointerSize, - 30); - - LargeObjectIterator it(this); - while (it.has_next()) { - // We only have code, sequential strings, or fixed arrays in large - // object space, and only fixed arrays can possibly contain pointers to - // the young generation. - HeapObject* object = it.next(); - if (object->IsFixedArray()) { - // Iterate the normal page remembered set range. - Page* page = Page::FromAddress(object->address()); - Address object_end = object->address() + object->Size(); - int count = Heap::IterateRSetRange(page->ObjectAreaStart(), - Min(page->ObjectAreaEnd(), object_end), - page->RSetStart(), - copy_object_func); - - // Iterate the extra array elements. - if (object_end > page->ObjectAreaEnd()) { - count += Heap::IterateRSetRange(page->ObjectAreaEnd(), object_end, - object_end, copy_object_func); - } - if (lo_rset_histogram != NULL) { - StatsTable::AddHistogramSample(lo_rset_histogram, count); - } - } - } -} - - -void LargeObjectSpace::FreeUnmarkedObjects() { - LargeObjectChunk* previous = NULL; - LargeObjectChunk* current = first_chunk_; - while (current != NULL) { - HeapObject* object = current->GetObject(); - if (object->IsMarked()) { - object->ClearMark(); - MarkCompactCollector::tracer()->decrement_marked_count(); - previous = current; - current = current->next(); - } else { - Address chunk_address = current->address(); - size_t chunk_size = current->size(); - - // Cut the chunk out from the chunk list. - current = current->next(); - if (previous == NULL) { - first_chunk_ = current; - } else { - previous->set_next(current); - } - - // Free the chunk. - if (object->IsCode()) { - LOG(CodeDeleteEvent(object->address())); - } - size_ -= chunk_size; - page_count_--; - MemoryAllocator::FreeRawMemory(chunk_address, chunk_size); - LOG(DeleteEvent("LargeObjectChunk", chunk_address)); - } - } -} - - -bool LargeObjectSpace::Contains(HeapObject* object) { - Address address = object->address(); - Page* page = Page::FromAddress(address); - - SLOW_ASSERT(!page->IsLargeObjectPage() - || !FindObject(address)->IsFailure()); - - return page->IsLargeObjectPage(); -} - - -#ifdef DEBUG -// We do not assume that the large object iterator works, because it depends -// on the invariants we are checking during verification. -void LargeObjectSpace::Verify() { - for (LargeObjectChunk* chunk = first_chunk_; - chunk != NULL; - chunk = chunk->next()) { - // Each chunk contains an object that starts at the large object page's - // object area start. - HeapObject* object = chunk->GetObject(); - Page* page = Page::FromAddress(object->address()); - ASSERT(object->address() == page->ObjectAreaStart()); - - // The first word should be a map, and we expect all map pointers to be - // in map space. - Map* map = object->map(); - ASSERT(map->IsMap()); - ASSERT(Heap::map_space()->Contains(map)); - - // We have only code, sequential strings, 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 IsRSetSet. - FixedArray* array = FixedArray::cast(object); - for (int j = 0; j < array->length(); j++) { - Object* element = array->get(j); - if (element->IsHeapObject()) { - HeapObject* element_object = HeapObject::cast(element); - ASSERT(Heap::Contains(element_object)); - ASSERT(element_object->map()->IsMap()); - if (Heap::InNewSpace(element_object)) { - ASSERT(Page::IsRSetSet(object->address(), - FixedArray::kHeaderSize + j * kPointerSize)); - } - } - } - } - } -} - - -void LargeObjectSpace::Print() { - LargeObjectIterator it(this); - while (it.has_next()) { - it.next()->Print(); - } -} - - -void LargeObjectSpace::ReportStatistics() { - PrintF(" size: %d\n", size_); - int num_objects = 0; - ClearHistograms(); - LargeObjectIterator it(this); - while (it.has_next()) { - num_objects++; - CollectHistogramInfo(it.next()); - } - - PrintF(" number of objects %d\n", num_objects); - if (num_objects > 0) ReportHistogram(false); -} - - -void LargeObjectSpace::CollectCodeStatistics() { - LargeObjectIterator obj_it(this); - while (obj_it.has_next()) { - HeapObject* obj = obj_it.next(); - if (obj->IsCode()) { - Code* code = Code::cast(obj); - code_kind_statistics[code->kind()] += code->Size(); - } - } -} - - -void LargeObjectSpace::PrintRSet() { - LargeObjectIterator it(this); - while (it.has_next()) { - HeapObject* object = it.next(); - if (object->IsFixedArray()) { - Page* page = Page::FromAddress(object->address()); - - Address allocation_top = object->address() + object->Size(); - PrintF("large page 0x%x:\n", page); - PrintRSetRange(page->RSetStart(), page->RSetEnd(), - reinterpret_cast<Object**>(object->address()), - allocation_top); - int extra_array_bytes = object->Size() - Page::kObjectAreaSize; - int extra_rset_bits = RoundUp(extra_array_bytes / kPointerSize, - kBitsPerInt); - PrintF("------------------------------------------------------------" - "-----------\n"); - PrintRSetRange(allocation_top, - allocation_top + extra_rset_bits / kBitsPerByte, - reinterpret_cast<Object**>(object->address() - + Page::kObjectAreaSize), - allocation_top); - PrintF("\n"); - } - } -} -#endif // DEBUG - -} } // namespace v8::internal |