b026021215
Review URL: http://codereview.chromium.org/203070 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2941 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2660 lines
82 KiB
C++
2660 lines
82 KiB
C++
// Copyright 2006-2008 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "v8.h"
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#include "macro-assembler.h"
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#include "mark-compact.h"
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#include "platform.h"
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namespace v8 {
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namespace internal {
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// For contiguous spaces, top should be in the space (or at the end) and limit
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// should be the end of the space.
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#define ASSERT_SEMISPACE_ALLOCATION_INFO(info, space) \
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ASSERT((space).low() <= (info).top \
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&& (info).top <= (space).high() \
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&& (info).limit == (space).high())
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// ----------------------------------------------------------------------------
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// HeapObjectIterator
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HeapObjectIterator::HeapObjectIterator(PagedSpace* space) {
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Initialize(space->bottom(), space->top(), NULL);
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}
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HeapObjectIterator::HeapObjectIterator(PagedSpace* space,
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HeapObjectCallback size_func) {
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Initialize(space->bottom(), space->top(), size_func);
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}
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HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start) {
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Initialize(start, space->top(), NULL);
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}
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HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start,
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HeapObjectCallback size_func) {
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Initialize(start, space->top(), size_func);
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}
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void HeapObjectIterator::Initialize(Address cur, Address end,
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HeapObjectCallback size_f) {
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cur_addr_ = cur;
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end_addr_ = end;
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end_page_ = Page::FromAllocationTop(end);
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size_func_ = size_f;
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Page* p = Page::FromAllocationTop(cur_addr_);
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cur_limit_ = (p == end_page_) ? end_addr_ : p->AllocationTop();
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#ifdef DEBUG
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Verify();
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#endif
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}
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bool HeapObjectIterator::HasNextInNextPage() {
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if (cur_addr_ == end_addr_) return false;
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Page* cur_page = Page::FromAllocationTop(cur_addr_);
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cur_page = cur_page->next_page();
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ASSERT(cur_page->is_valid());
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cur_addr_ = cur_page->ObjectAreaStart();
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cur_limit_ = (cur_page == end_page_) ? end_addr_ : cur_page->AllocationTop();
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ASSERT(cur_addr_ < cur_limit_);
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#ifdef DEBUG
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Verify();
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#endif
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return true;
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}
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#ifdef DEBUG
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void HeapObjectIterator::Verify() {
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Page* p = Page::FromAllocationTop(cur_addr_);
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ASSERT(p == Page::FromAllocationTop(cur_limit_));
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ASSERT(p->Offset(cur_addr_) <= p->Offset(cur_limit_));
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}
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#endif
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// -----------------------------------------------------------------------------
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// PageIterator
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PageIterator::PageIterator(PagedSpace* space, Mode mode) : space_(space) {
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prev_page_ = NULL;
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switch (mode) {
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case PAGES_IN_USE:
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stop_page_ = space->AllocationTopPage();
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break;
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case PAGES_USED_BY_MC:
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stop_page_ = space->MCRelocationTopPage();
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break;
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case ALL_PAGES:
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#ifdef DEBUG
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// Verify that the cached last page in the space is actually the
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// last page.
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for (Page* p = space->first_page_; p->is_valid(); p = p->next_page()) {
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if (!p->next_page()->is_valid()) {
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ASSERT(space->last_page_ == p);
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}
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}
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#endif
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stop_page_ = space->last_page_;
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break;
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}
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}
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// -----------------------------------------------------------------------------
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// Page
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#ifdef DEBUG
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Page::RSetState Page::rset_state_ = Page::IN_USE;
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#endif
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// -----------------------------------------------------------------------------
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// MemoryAllocator
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//
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int MemoryAllocator::capacity_ = 0;
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int MemoryAllocator::size_ = 0;
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VirtualMemory* MemoryAllocator::initial_chunk_ = NULL;
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// 270 is an estimate based on the static default heap size of a pair of 256K
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// semispaces and a 64M old generation.
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const int kEstimatedNumberOfChunks = 270;
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List<MemoryAllocator::ChunkInfo> MemoryAllocator::chunks_(
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kEstimatedNumberOfChunks);
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List<int> MemoryAllocator::free_chunk_ids_(kEstimatedNumberOfChunks);
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int MemoryAllocator::max_nof_chunks_ = 0;
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int MemoryAllocator::top_ = 0;
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void MemoryAllocator::Push(int free_chunk_id) {
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ASSERT(max_nof_chunks_ > 0);
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ASSERT(top_ < max_nof_chunks_);
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free_chunk_ids_[top_++] = free_chunk_id;
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}
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int MemoryAllocator::Pop() {
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ASSERT(top_ > 0);
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return free_chunk_ids_[--top_];
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}
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bool MemoryAllocator::Setup(int capacity) {
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capacity_ = RoundUp(capacity, Page::kPageSize);
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// Over-estimate the size of chunks_ array. It assumes the expansion of old
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// space is always in the unit of a chunk (kChunkSize) except the last
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// expansion.
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//
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// Due to alignment, allocated space might be one page less than required
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// number (kPagesPerChunk) of pages for old spaces.
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//
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// Reserve two chunk ids for semispaces, one for map space, one for old
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// space, and one for code space.
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max_nof_chunks_ = (capacity_ / (kChunkSize - Page::kPageSize)) + 5;
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if (max_nof_chunks_ > kMaxNofChunks) return false;
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size_ = 0;
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ChunkInfo info; // uninitialized element.
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for (int i = max_nof_chunks_ - 1; i >= 0; i--) {
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chunks_.Add(info);
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free_chunk_ids_.Add(i);
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}
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top_ = max_nof_chunks_;
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return true;
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}
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void MemoryAllocator::TearDown() {
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for (int i = 0; i < max_nof_chunks_; i++) {
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if (chunks_[i].address() != NULL) DeleteChunk(i);
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}
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chunks_.Clear();
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free_chunk_ids_.Clear();
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if (initial_chunk_ != NULL) {
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LOG(DeleteEvent("InitialChunk", initial_chunk_->address()));
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delete initial_chunk_;
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initial_chunk_ = NULL;
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}
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ASSERT(top_ == max_nof_chunks_); // all chunks are free
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top_ = 0;
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capacity_ = 0;
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size_ = 0;
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max_nof_chunks_ = 0;
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}
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void* MemoryAllocator::AllocateRawMemory(const size_t requested,
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size_t* allocated,
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Executability executable) {
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if (size_ + static_cast<int>(requested) > capacity_) return NULL;
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void* mem = OS::Allocate(requested, allocated, executable == EXECUTABLE);
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int alloced = *allocated;
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size_ += alloced;
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Counters::memory_allocated.Increment(alloced);
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return mem;
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}
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void MemoryAllocator::FreeRawMemory(void* mem, size_t length) {
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OS::Free(mem, length);
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Counters::memory_allocated.Decrement(length);
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size_ -= length;
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ASSERT(size_ >= 0);
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}
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void* MemoryAllocator::ReserveInitialChunk(const size_t requested) {
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ASSERT(initial_chunk_ == NULL);
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initial_chunk_ = new VirtualMemory(requested);
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CHECK(initial_chunk_ != NULL);
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if (!initial_chunk_->IsReserved()) {
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delete initial_chunk_;
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initial_chunk_ = NULL;
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return NULL;
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}
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// We are sure that we have mapped a block of requested addresses.
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ASSERT(initial_chunk_->size() == requested);
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LOG(NewEvent("InitialChunk", initial_chunk_->address(), requested));
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size_ += requested;
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return initial_chunk_->address();
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}
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static int PagesInChunk(Address start, size_t size) {
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// The first page starts on the first page-aligned address from start onward
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// and the last page ends on the last page-aligned address before
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// start+size. Page::kPageSize is a power of two so we can divide by
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// shifting.
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return (RoundDown(start + size, Page::kPageSize)
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- RoundUp(start, Page::kPageSize)) >> Page::kPageSizeBits;
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}
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Page* MemoryAllocator::AllocatePages(int requested_pages, int* allocated_pages,
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PagedSpace* owner) {
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if (requested_pages <= 0) return Page::FromAddress(NULL);
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size_t chunk_size = requested_pages * Page::kPageSize;
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// There is not enough space to guarantee the desired number pages can be
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// allocated.
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if (size_ + static_cast<int>(chunk_size) > capacity_) {
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// Request as many pages as we can.
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chunk_size = capacity_ - size_;
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requested_pages = chunk_size >> Page::kPageSizeBits;
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if (requested_pages <= 0) return Page::FromAddress(NULL);
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}
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void* chunk = AllocateRawMemory(chunk_size, &chunk_size, owner->executable());
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if (chunk == NULL) return Page::FromAddress(NULL);
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LOG(NewEvent("PagedChunk", chunk, chunk_size));
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*allocated_pages = PagesInChunk(static_cast<Address>(chunk), chunk_size);
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if (*allocated_pages == 0) {
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FreeRawMemory(chunk, chunk_size);
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LOG(DeleteEvent("PagedChunk", chunk));
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return Page::FromAddress(NULL);
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}
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int chunk_id = Pop();
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chunks_[chunk_id].init(static_cast<Address>(chunk), chunk_size, owner);
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return InitializePagesInChunk(chunk_id, *allocated_pages, owner);
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}
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Page* MemoryAllocator::CommitPages(Address start, size_t size,
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PagedSpace* owner, int* num_pages) {
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ASSERT(start != NULL);
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*num_pages = PagesInChunk(start, size);
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ASSERT(*num_pages > 0);
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ASSERT(initial_chunk_ != NULL);
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ASSERT(InInitialChunk(start));
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ASSERT(InInitialChunk(start + size - 1));
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if (!initial_chunk_->Commit(start, size, owner->executable() == EXECUTABLE)) {
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return Page::FromAddress(NULL);
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}
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Counters::memory_allocated.Increment(size);
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// So long as we correctly overestimated the number of chunks we should not
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// run out of chunk ids.
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CHECK(!OutOfChunkIds());
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int chunk_id = Pop();
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chunks_[chunk_id].init(start, size, owner);
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return InitializePagesInChunk(chunk_id, *num_pages, owner);
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}
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bool MemoryAllocator::CommitBlock(Address start,
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size_t size,
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Executability executable) {
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ASSERT(start != NULL);
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ASSERT(size > 0);
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ASSERT(initial_chunk_ != NULL);
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ASSERT(InInitialChunk(start));
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ASSERT(InInitialChunk(start + size - 1));
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if (!initial_chunk_->Commit(start, size, executable)) return false;
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Counters::memory_allocated.Increment(size);
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return true;
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}
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bool MemoryAllocator::UncommitBlock(Address start, size_t size) {
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ASSERT(start != NULL);
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ASSERT(size > 0);
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ASSERT(initial_chunk_ != NULL);
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ASSERT(InInitialChunk(start));
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ASSERT(InInitialChunk(start + size - 1));
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if (!initial_chunk_->Uncommit(start, size)) return false;
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Counters::memory_allocated.Decrement(size);
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return true;
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}
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Page* MemoryAllocator::InitializePagesInChunk(int chunk_id, int pages_in_chunk,
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PagedSpace* owner) {
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ASSERT(IsValidChunk(chunk_id));
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ASSERT(pages_in_chunk > 0);
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Address chunk_start = chunks_[chunk_id].address();
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Address low = RoundUp(chunk_start, Page::kPageSize);
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#ifdef DEBUG
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size_t chunk_size = chunks_[chunk_id].size();
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Address high = RoundDown(chunk_start + chunk_size, Page::kPageSize);
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ASSERT(pages_in_chunk <=
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((OffsetFrom(high) - OffsetFrom(low)) / Page::kPageSize));
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#endif
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Address page_addr = low;
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for (int i = 0; i < pages_in_chunk; i++) {
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Page* p = Page::FromAddress(page_addr);
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p->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id;
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p->is_normal_page = 1;
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page_addr += Page::kPageSize;
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}
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// Set the next page of the last page to 0.
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Page* last_page = Page::FromAddress(page_addr - Page::kPageSize);
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last_page->opaque_header = OffsetFrom(0) | chunk_id;
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return Page::FromAddress(low);
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}
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Page* MemoryAllocator::FreePages(Page* p) {
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if (!p->is_valid()) return p;
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// Find the first page in the same chunk as 'p'
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Page* first_page = FindFirstPageInSameChunk(p);
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Page* page_to_return = Page::FromAddress(NULL);
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if (p != first_page) {
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// Find the last page in the same chunk as 'prev'.
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Page* last_page = FindLastPageInSameChunk(p);
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first_page = GetNextPage(last_page); // first page in next chunk
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// set the next_page of last_page to NULL
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SetNextPage(last_page, Page::FromAddress(NULL));
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page_to_return = p; // return 'p' when exiting
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}
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while (first_page->is_valid()) {
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int chunk_id = GetChunkId(first_page);
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ASSERT(IsValidChunk(chunk_id));
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// Find the first page of the next chunk before deleting this chunk.
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first_page = GetNextPage(FindLastPageInSameChunk(first_page));
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// Free the current chunk.
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DeleteChunk(chunk_id);
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}
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return page_to_return;
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}
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void MemoryAllocator::DeleteChunk(int chunk_id) {
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ASSERT(IsValidChunk(chunk_id));
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ChunkInfo& c = chunks_[chunk_id];
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// We cannot free a chunk contained in the initial chunk because it was not
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// allocated with AllocateRawMemory. Instead we uncommit the virtual
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// memory.
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if (InInitialChunk(c.address())) {
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// TODO(1240712): VirtualMemory::Uncommit has a return value which
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// is ignored here.
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initial_chunk_->Uncommit(c.address(), c.size());
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Counters::memory_allocated.Decrement(c.size());
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} else {
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LOG(DeleteEvent("PagedChunk", c.address()));
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FreeRawMemory(c.address(), c.size());
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}
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c.init(NULL, 0, NULL);
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Push(chunk_id);
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}
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Page* MemoryAllocator::FindFirstPageInSameChunk(Page* p) {
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int chunk_id = GetChunkId(p);
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ASSERT(IsValidChunk(chunk_id));
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Address low = RoundUp(chunks_[chunk_id].address(), Page::kPageSize);
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return Page::FromAddress(low);
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}
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Page* MemoryAllocator::FindLastPageInSameChunk(Page* p) {
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int chunk_id = GetChunkId(p);
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ASSERT(IsValidChunk(chunk_id));
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Address chunk_start = chunks_[chunk_id].address();
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size_t chunk_size = chunks_[chunk_id].size();
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Address high = RoundDown(chunk_start + chunk_size, Page::kPageSize);
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ASSERT(chunk_start <= p->address() && p->address() < high);
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return Page::FromAddress(high - Page::kPageSize);
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}
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#ifdef DEBUG
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void MemoryAllocator::ReportStatistics() {
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float pct = static_cast<float>(capacity_ - size_) / capacity_;
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PrintF(" capacity: %d, used: %d, available: %%%d\n\n",
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capacity_, size_, static_cast<int>(pct*100));
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}
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#endif
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// -----------------------------------------------------------------------------
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// PagedSpace implementation
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PagedSpace::PagedSpace(int max_capacity,
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AllocationSpace id,
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Executability executable)
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: Space(id, executable) {
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max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize)
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* Page::kObjectAreaSize;
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accounting_stats_.Clear();
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allocation_info_.top = NULL;
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allocation_info_.limit = NULL;
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mc_forwarding_info_.top = NULL;
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mc_forwarding_info_.limit = NULL;
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}
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bool PagedSpace::Setup(Address start, size_t size) {
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if (HasBeenSetup()) return false;
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int num_pages = 0;
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// Try to use the virtual memory range passed to us. If it is too small to
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// contain at least one page, ignore it and allocate instead.
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int pages_in_chunk = PagesInChunk(start, size);
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if (pages_in_chunk > 0) {
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first_page_ = MemoryAllocator::CommitPages(RoundUp(start, Page::kPageSize),
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Page::kPageSize * pages_in_chunk,
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this, &num_pages);
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} else {
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int requested_pages = Min(MemoryAllocator::kPagesPerChunk,
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max_capacity_ / Page::kObjectAreaSize);
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first_page_ =
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MemoryAllocator::AllocatePages(requested_pages, &num_pages, this);
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if (!first_page_->is_valid()) return false;
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}
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// We are sure that the first page is valid and that we have at least one
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// page.
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ASSERT(first_page_->is_valid());
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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
|