Initial export.
git-svn-id: http://v8.googlecode.com/svn/trunk@2 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
diff --git a/src/spaces.cc b/src/spaces.cc
new file mode 100644
index 0000000..52f6391
--- /dev/null
+++ b/src/spaces.cc
@@ -0,0 +1,2647 @@
+// Copyright 2006-2008 Google Inc. All Rights Reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "v8.h"
+
+#include "macro-assembler.h"
+#include "mark-compact.h"
+#include "platform.h"
+
+namespace v8 { namespace internal {
+
+#ifdef DEBUG
+DECLARE_bool(heap_stats);
+DEFINE_bool(collect_heap_spill_statistics, false,
+ "report heap spill statistics along with heap_stats "
+ "(requires heap_stats)");
+#endif
+
+#ifdef ENABLE_LOGGING_AND_PROFILING
+DECLARE_bool(log_gc);
+#endif
+
+// For paged spaces, top and limit should always be in the same page and top
+// should not be greater than limit.
+#define ASSERT_PAGED_ALLOCATION_INFO(info) \
+ ASSERT((Page::FromAllocationTop((info).top) == \
+ Page::FromAllocationTop((info).limit)) \
+ &&((info).top <= (info).limit))
+
+
+// For contiguous spaces, top should be in the space (or at the end) and limit
+// should be the end of the space.
+#define ASSERT_SEMISPACE_ALLOCATION_INFO(info, space) \
+ ASSERT((space)->low() <= (info).top \
+ && (info).top <= (space)->high() \
+ && (info).limit == (space)->high())
+
+// ----------------------------------------------------------------------------
+// SpaceIterator
+
+SpaceIterator::SpaceIterator() : current_space_(NEW_SPACE), iterator_(NULL) {
+ // SpaceIterator depends on AllocationSpace enumeration starts with NEW_SPACE.
+ ASSERT(NEW_SPACE == 0);
+}
+
+
+SpaceIterator::~SpaceIterator() {
+ // Delete active iterator if any.
+ if (iterator_ != NULL) delete iterator_;
+}
+
+
+bool SpaceIterator::has_next() {
+ // Iterate until no more spaces.
+ return current_space_ != LAST_SPACE;
+}
+
+
+ObjectIterator* SpaceIterator::next() {
+ if (iterator_ != NULL) {
+ delete iterator_;
+ iterator_ = NULL;
+ // Move to the next space
+ current_space_++;
+ if (current_space_ > LAST_SPACE) {
+ return NULL;
+ }
+ }
+
+ // Return iterator for the new current space.
+ return CreateIterator();
+}
+
+
+// Create an iterator for the space to iterate.
+ObjectIterator* SpaceIterator::CreateIterator() {
+ ASSERT(iterator_ == NULL);
+
+ switch (current_space_) {
+ case NEW_SPACE:
+ iterator_ = new SemiSpaceIterator(Heap::new_space());
+ break;
+ case OLD_SPACE:
+ iterator_ = new HeapObjectIterator(Heap::old_space());
+ break;
+ case CODE_SPACE:
+ iterator_ = new HeapObjectIterator(Heap::code_space());
+ break;
+ case MAP_SPACE:
+ iterator_ = new HeapObjectIterator(Heap::map_space());
+ break;
+ case LO_SPACE:
+ iterator_ = new LargeObjectIterator(Heap::lo_space());
+ break;
+ }
+
+ // Return the newly allocated iterator;
+ ASSERT(iterator_ != NULL);
+ return iterator_;
+}
+
+
+// ----------------------------------------------------------------------------
+// HeapObjectIterator
+
+HeapObjectIterator::HeapObjectIterator(PagedSpace* space) {
+ Initialize(space->bottom(), space->top(), NULL);
+}
+
+
+HeapObjectIterator::HeapObjectIterator(PagedSpace* space,
+ HeapObjectCallback size_func) {
+ Initialize(space->bottom(), space->top(), size_func);
+}
+
+
+HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start) {
+ Initialize(start, space->top(), NULL);
+}
+
+
+HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start,
+ HeapObjectCallback size_func) {
+ Initialize(start, space->top(), size_func);
+}
+
+
+void HeapObjectIterator::Initialize(Address cur, Address end,
+ HeapObjectCallback size_f) {
+ cur_addr_ = cur;
+ end_addr_ = end;
+ end_page_ = Page::FromAllocationTop(end);
+ size_func_ = size_f;
+ Page* p = Page::FromAllocationTop(cur_addr_);
+ cur_limit_ = (p == end_page_) ? end_addr_ : p->AllocationTop();
+
+#ifdef DEBUG
+ Verify();
+#endif
+}
+
+
+bool HeapObjectIterator::HasNextInNextPage() {
+ if (cur_addr_ == end_addr_) return false;
+
+ Page* cur_page = Page::FromAllocationTop(cur_addr_);
+ cur_page = cur_page->next_page();
+ ASSERT(cur_page->is_valid());
+
+ cur_addr_ = cur_page->ObjectAreaStart();
+ cur_limit_ = (cur_page == end_page_) ? end_addr_ : cur_page->AllocationTop();
+
+ ASSERT(cur_addr_ < cur_limit_);
+#ifdef DEBUG
+ Verify();
+#endif
+ return true;
+}
+
+
+#ifdef DEBUG
+void HeapObjectIterator::Verify() {
+ Page* p = Page::FromAllocationTop(cur_addr_);
+ ASSERT(p == Page::FromAllocationTop(cur_limit_));
+ ASSERT(p->Offset(cur_addr_) <= p->Offset(cur_limit_));
+}
+#endif
+
+
+// -----------------------------------------------------------------------------
+// PageIterator
+
+PageIterator::PageIterator(PagedSpace* space, Mode mode) {
+ cur_page_ = space->first_page_;
+ switch (mode) {
+ case PAGES_IN_USE:
+ stop_page_ = space->AllocationTopPage()->next_page();
+ break;
+ case PAGES_USED_BY_MC:
+ stop_page_ = space->MCRelocationTopPage()->next_page();
+ break;
+ case ALL_PAGES:
+ stop_page_ = Page::FromAddress(NULL);
+ break;
+ default:
+ UNREACHABLE();
+ }
+}
+
+
+// -----------------------------------------------------------------------------
+// Page
+
+#ifdef DEBUG
+Page::RSetState Page::rset_state_ = Page::IN_USE;
+#endif
+
+// -----------------------------------------------------------------------------
+// MemoryAllocator
+//
+int MemoryAllocator::capacity_ = 0;
+int MemoryAllocator::size_ = 0;
+
+VirtualMemory* MemoryAllocator::initial_chunk_ = NULL;
+
+// 270 is an estimate based on the static default heap size of a pair of 256K
+// semispaces and a 64M old generation.
+const int kEstimatedNumberOfChunks = 270;
+List<MemoryAllocator::ChunkInfo> MemoryAllocator::chunks_(
+ kEstimatedNumberOfChunks);
+List<int> MemoryAllocator::free_chunk_ids_(kEstimatedNumberOfChunks);
+int MemoryAllocator::max_nof_chunks_ = 0;
+int MemoryAllocator::top_ = 0;
+
+
+void MemoryAllocator::Push(int free_chunk_id) {
+ ASSERT(max_nof_chunks_ > 0);
+ ASSERT(top_ < max_nof_chunks_);
+ free_chunk_ids_[top_++] = free_chunk_id;
+}
+
+
+int MemoryAllocator::Pop() {
+ ASSERT(top_ > 0);
+ return free_chunk_ids_[--top_];
+}
+
+
+bool MemoryAllocator::Setup(int capacity) {
+ capacity_ = RoundUp(capacity, Page::kPageSize);
+
+ // Over-estimate the size of chunks_ array. It assumes the expansion of old
+ // space is always in the unit of a chunk (kChunkSize) except the last
+ // expansion.
+ //
+ // Due to alignment, allocated space might be one page less than required
+ // number (kPagesPerChunk) of pages for old spaces.
+ //
+ // Reserve two chunk ids for semispaces, one for map space and one for old
+ // space.
+ max_nof_chunks_ = (capacity_ / (kChunkSize - Page::kPageSize)) + 4;
+ if (max_nof_chunks_ > kMaxNofChunks) return false;
+
+ size_ = 0;
+ ChunkInfo info; // uninitialized element.
+ for (int i = max_nof_chunks_ - 1; i >= 0; i--) {
+ chunks_.Add(info);
+ free_chunk_ids_.Add(i);
+ }
+ top_ = max_nof_chunks_;
+ return true;
+}
+
+
+void MemoryAllocator::TearDown() {
+ for (int i = 0; i < max_nof_chunks_; i++) {
+ if (chunks_[i].address() != NULL) DeleteChunk(i);
+ }
+ chunks_.Clear();
+ free_chunk_ids_.Clear();
+
+ if (initial_chunk_ != NULL) {
+ LOG(DeleteEvent("InitialChunk", initial_chunk_->address()));
+ delete initial_chunk_;
+ initial_chunk_ = NULL;
+ }
+
+ ASSERT(top_ == max_nof_chunks_); // all chunks are free
+ top_ = 0;
+ capacity_ = 0;
+ size_ = 0;
+ max_nof_chunks_ = 0;
+}
+
+
+void* MemoryAllocator::AllocateRawMemory(const size_t requested,
+ size_t* allocated) {
+ if (size_ + static_cast<int>(requested) > capacity_) return NULL;
+
+ void* mem = OS::Allocate(requested, allocated);
+ int alloced = *allocated;
+ size_ += alloced;
+ Counters::memory_allocated.Increment(alloced);
+ return mem;
+}
+
+
+void MemoryAllocator::FreeRawMemory(void* mem, size_t length) {
+ OS::Free(mem, length);
+ Counters::memory_allocated.Decrement(length);
+ size_ -= length;
+ ASSERT(size_ >= 0);
+}
+
+
+void* MemoryAllocator::ReserveInitialChunk(const size_t requested) {
+ ASSERT(initial_chunk_ == NULL);
+
+ initial_chunk_ = new VirtualMemory(requested);
+ CHECK(initial_chunk_ != NULL);
+ if (!initial_chunk_->IsReserved()) {
+ delete initial_chunk_;
+ initial_chunk_ = NULL;
+ return NULL;
+ }
+
+ // We are sure that we have mapped a block of requested addresses.
+ ASSERT(initial_chunk_->size() == requested);
+ LOG(NewEvent("InitialChunk", initial_chunk_->address(), requested));
+ size_ += requested;
+ return initial_chunk_->address();
+}
+
+
+static int PagesInChunk(Address start, size_t size) {
+ // The first page starts on the first page-aligned address from start onward
+ // and the last page ends on the last page-aligned address before
+ // start+size. Page::kPageSize is a power of two so we can divide by
+ // shifting.
+ return (RoundDown(start + size, Page::kPageSize)
+ - RoundUp(start, Page::kPageSize)) >> Page::kPageSizeBits;
+}
+
+
+Page* MemoryAllocator::AllocatePages(int requested_pages, int* allocated_pages,
+ PagedSpace* owner) {
+ if (requested_pages <= 0) return Page::FromAddress(NULL);
+ size_t chunk_size = requested_pages * Page::kPageSize;
+
+ // There is not enough space to guarantee the desired number pages can be
+ // allocated.
+ if (size_ + static_cast<int>(chunk_size) > capacity_) {
+ // Request as many pages as we can.
+ chunk_size = capacity_ - size_;
+ requested_pages = chunk_size >> Page::kPageSizeBits;
+
+ if (requested_pages <= 0) return Page::FromAddress(NULL);
+ }
+
+ void* chunk = AllocateRawMemory(chunk_size, &chunk_size);
+ if (chunk == NULL) return Page::FromAddress(NULL);
+ LOG(NewEvent("PagedChunk", chunk, chunk_size));
+
+ *allocated_pages = PagesInChunk(static_cast<Address>(chunk), chunk_size);
+ if (*allocated_pages == 0) {
+ FreeRawMemory(chunk, chunk_size);
+ LOG(DeleteEvent("PagedChunk", chunk));
+ return Page::FromAddress(NULL);
+ }
+
+ int chunk_id = Pop();
+ chunks_[chunk_id].init(static_cast<Address>(chunk), chunk_size, owner);
+
+ return InitializePagesInChunk(chunk_id, *allocated_pages, owner);
+}
+
+
+Page* MemoryAllocator::CommitPages(Address start, size_t size,
+ PagedSpace* owner, int* num_pages) {
+ ASSERT(start != NULL);
+ *num_pages = PagesInChunk(start, size);
+ ASSERT(*num_pages > 0);
+ ASSERT(initial_chunk_ != NULL);
+ ASSERT(initial_chunk_->address() <= start);
+ ASSERT(start + size <= reinterpret_cast<Address>(initial_chunk_->address())
+ + initial_chunk_->size());
+
+ if (!initial_chunk_->Commit(start, size)) {
+ return Page::FromAddress(NULL);
+ }
+ Counters::memory_allocated.Increment(size);
+
+ // So long as we correctly overestimated the number of chunks we should not
+ // run out of chunk ids.
+ CHECK(!OutOfChunkIds());
+ int chunk_id = Pop();
+ chunks_[chunk_id].init(start, size, owner);
+ return InitializePagesInChunk(chunk_id, *num_pages, owner);
+}
+
+
+bool MemoryAllocator::CommitBlock(Address start, size_t size) {
+ ASSERT(start != NULL);
+ ASSERT(size > 0);
+ ASSERT(initial_chunk_ != NULL);
+ ASSERT(initial_chunk_->address() <= start);
+ ASSERT(start + size <= reinterpret_cast<Address>(initial_chunk_->address())
+ + initial_chunk_->size());
+
+ if (!initial_chunk_->Commit(start, size)) return false;
+ Counters::memory_allocated.Increment(size);
+ return true;
+}
+
+
+Page* MemoryAllocator::InitializePagesInChunk(int chunk_id, int pages_in_chunk,
+ PagedSpace* owner) {
+ ASSERT(IsValidChunk(chunk_id));
+ ASSERT(pages_in_chunk > 0);
+
+ Address chunk_start = chunks_[chunk_id].address();
+
+ Address low = RoundUp(chunk_start, Page::kPageSize);
+
+#ifdef DEBUG
+ size_t chunk_size = chunks_[chunk_id].size();
+ Address high = RoundDown(chunk_start + chunk_size, Page::kPageSize);
+ ASSERT(pages_in_chunk <=
+ ((OffsetFrom(high) - OffsetFrom(low)) / Page::kPageSize));
+#endif
+
+ Address page_addr = low;
+ for (int i = 0; i < pages_in_chunk; i++) {
+ Page* p = Page::FromAddress(page_addr);
+ p->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id;
+ p->is_normal_page = 1;
+ page_addr += Page::kPageSize;
+ }
+
+ // Set the next page of the last page to 0.
+ Page* last_page = Page::FromAddress(page_addr - Page::kPageSize);
+ last_page->opaque_header = OffsetFrom(0) | chunk_id;
+
+ return Page::FromAddress(low);
+}
+
+
+Page* MemoryAllocator::FreePages(Page* p) {
+ if (!p->is_valid()) return p;
+
+ // Find the first page in the same chunk as 'p'
+ Page* first_page = FindFirstPageInSameChunk(p);
+ Page* page_to_return = Page::FromAddress(NULL);
+
+ if (p != first_page) {
+ // Find the last page in the same chunk as 'prev'.
+ Page* last_page = FindLastPageInSameChunk(p);
+ first_page = GetNextPage(last_page); // first page in next chunk
+
+ // set the next_page of last_page to NULL
+ SetNextPage(last_page, Page::FromAddress(NULL));
+ page_to_return = p; // return 'p' when exiting
+ }
+
+ while (first_page->is_valid()) {
+ int chunk_id = GetChunkId(first_page);
+ ASSERT(IsValidChunk(chunk_id));
+
+ // Find the first page of the next chunk before deleting this chunk.
+ first_page = GetNextPage(FindLastPageInSameChunk(first_page));
+
+ // Free the current chunk.
+ DeleteChunk(chunk_id);
+ }
+
+ return page_to_return;
+}
+
+
+void MemoryAllocator::DeleteChunk(int chunk_id) {
+ ASSERT(IsValidChunk(chunk_id));
+
+ ChunkInfo& c = chunks_[chunk_id];
+
+ // We cannot free a chunk contained in the initial chunk because it was not
+ // allocated with AllocateRawMemory. Instead we uncommit the virtual
+ // memory.
+ bool in_initial_chunk = false;
+ if (initial_chunk_ != NULL) {
+ Address start = static_cast<Address>(initial_chunk_->address());
+ Address end = start + initial_chunk_->size();
+ in_initial_chunk = (start <= c.address()) && (c.address() < end);
+ }
+
+ if (in_initial_chunk) {
+ // TODO(1240712): VirtualMemory::Uncommit has a return value which
+ // is ignored here.
+ initial_chunk_->Uncommit(c.address(), c.size());
+ Counters::memory_allocated.Decrement(c.size());
+ } else {
+ LOG(DeleteEvent("PagedChunk", c.address()));
+ FreeRawMemory(c.address(), c.size());
+ }
+ c.init(NULL, 0, NULL);
+ Push(chunk_id);
+}
+
+
+Page* MemoryAllocator::FindFirstPageInSameChunk(Page* p) {
+ int chunk_id = GetChunkId(p);
+ ASSERT(IsValidChunk(chunk_id));
+
+ Address low = RoundUp(chunks_[chunk_id].address(), Page::kPageSize);
+ return Page::FromAddress(low);
+}
+
+
+Page* MemoryAllocator::FindLastPageInSameChunk(Page* p) {
+ int chunk_id = GetChunkId(p);
+ ASSERT(IsValidChunk(chunk_id));
+
+ Address chunk_start = chunks_[chunk_id].address();
+ size_t chunk_size = chunks_[chunk_id].size();
+
+ Address high = RoundDown(chunk_start + chunk_size, Page::kPageSize);
+ ASSERT(chunk_start <= p->address() && p->address() < high);
+
+ return Page::FromAddress(high - Page::kPageSize);
+}
+
+
+#ifdef DEBUG
+void MemoryAllocator::ReportStatistics() {
+ float pct = static_cast<float>(capacity_ - size_) / capacity_;
+ PrintF(" capacity: %d, used: %d, available: %%%d\n\n",
+ capacity_, size_, static_cast<int>(pct*100));
+}
+#endif
+
+
+// -----------------------------------------------------------------------------
+// PagedSpace implementation
+
+PagedSpace::PagedSpace(int max_capacity, AllocationSpace id) {
+ ASSERT(id == OLD_SPACE || id == CODE_SPACE || id == MAP_SPACE);
+ max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize)
+ * Page::kObjectAreaSize;
+ identity_ = id;
+ accounting_stats_.Clear();
+
+ allocation_mode_ = LINEAR;
+
+ allocation_info_.top = NULL;
+ allocation_info_.limit = NULL;
+
+ mc_forwarding_info_.top = NULL;
+ mc_forwarding_info_.limit = NULL;
+}
+
+
+bool PagedSpace::Setup(Address start, size_t size) {
+ if (HasBeenSetup()) return false;
+
+ int num_pages = 0;
+ // Try to use the virtual memory range passed to us. If it is too small to
+ // contain at least one page, ignore it and allocate instead.
+ if (PagesInChunk(start, size) > 0) {
+ first_page_ = MemoryAllocator::CommitPages(start, size, this, &num_pages);
+ } else {
+ int requested_pages = Min(MemoryAllocator::kPagesPerChunk,
+ max_capacity_ / Page::kObjectAreaSize);
+ first_page_ =
+ MemoryAllocator::AllocatePages(requested_pages, &num_pages, this);
+ if (!first_page_->is_valid()) return false;
+ }
+
+ // We are sure that the first page is valid and that we have at least one
+ // page.
+ ASSERT(first_page_->is_valid());
+ ASSERT(num_pages > 0);
+ accounting_stats_.ExpandSpace(num_pages * Page::kObjectAreaSize);
+ ASSERT(Capacity() <= max_capacity_);
+
+ for (Page* p = first_page_; p->is_valid(); p = p->next_page()) {
+ p->ClearRSet();
+ }
+
+ // Use first_page_ for allocation.
+ SetAllocationInfo(&allocation_info_, first_page_);
+
+ return true;
+}
+
+
+bool PagedSpace::HasBeenSetup() {
+ return (Capacity() > 0);
+}
+
+
+void PagedSpace::TearDown() {
+ first_page_ = MemoryAllocator::FreePages(first_page_);
+ ASSERT(!first_page_->is_valid());
+
+ accounting_stats_.Clear();
+}
+
+
+void PagedSpace::ClearRSet() {
+ PageIterator it(this, PageIterator::ALL_PAGES);
+ while (it.has_next()) {
+ it.next()->ClearRSet();
+ }
+}
+
+
+Object* PagedSpace::FindObject(Address addr) {
+#ifdef DEBUG
+ // Note: this function can only be called before or after mark-compact GC
+ // because it accesses map pointers.
+ ASSERT(!MarkCompactCollector::in_use());
+#endif
+
+ if (!Contains(addr)) return Failure::Exception();
+
+ Page* p = Page::FromAddress(addr);
+ 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;
+ }
+
+ return Failure::Exception();
+}
+
+
+void PagedSpace::SetAllocationInfo(AllocationInfo* alloc_info, Page* p) {
+ alloc_info->top = p->ObjectAreaStart();
+ alloc_info->limit = p->ObjectAreaEnd();
+ ASSERT_PAGED_ALLOCATION_INFO(*alloc_info);
+}
+
+
+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();
+}
+
+
+void PagedSpace::SetLinearAllocationOnly(bool linear_only) {
+ if (linear_only) {
+ // Note that the free_list is not cleared. If we switch back to
+ // FREE_LIST mode it will be available for use. Resetting it
+ // requires correct accounting for the wasted bytes.
+ allocation_mode_ = LINEAR_ONLY;
+ } else {
+ ASSERT(allocation_mode_ == LINEAR_ONLY);
+ allocation_mode_ = LINEAR;
+ }
+}
+
+
+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);
+}
+
+
+bool PagedSpace::Expand(Page* last_page) {
+ ASSERT(max_capacity_ % Page::kObjectAreaSize == 0);
+ ASSERT(Capacity() % Page::kObjectAreaSize == 0);
+
+ if (Capacity() == max_capacity_) return false;
+
+ ASSERT(Capacity() < max_capacity_);
+ // Last page must be valid and its next page is invalid.
+ ASSERT(last_page->is_valid() && !last_page->next_page()->is_valid());
+
+ int available_pages = (max_capacity_ - Capacity()) / Page::kObjectAreaSize;
+ if (available_pages <= 0) return false;
+
+ int desired_pages = Min(available_pages, MemoryAllocator::kPagesPerChunk);
+ Page* p = MemoryAllocator::AllocatePages(desired_pages, &desired_pages, this);
+ if (!p->is_valid()) return false;
+
+ accounting_stats_.ExpandSpace(desired_pages * Page::kObjectAreaSize);
+ ASSERT(Capacity() <= max_capacity_);
+
+ MemoryAllocator::SetNextPage(last_page, p);
+
+ // Clear remembered set of new pages.
+ while (p->is_valid()) {
+ p->ClearRSet();
+ p = p->next_page();
+ }
+
+ return true;
+}
+
+
+#ifdef DEBUG
+int PagedSpace::CountTotalPages() {
+ int count = 0;
+ for (Page* p = first_page_; p->is_valid(); p = p->next_page()) {
+ count++;
+ }
+ return count;
+}
+#endif
+
+
+void PagedSpace::Shrink() {
+ // Release half of free pages.
+ Page* top_page = AllocationTopPage();
+ ASSERT(top_page->is_valid());
+
+ // Loop over the pages from the top page to the end of the space to count
+ // the number of pages to keep and find the last page to keep.
+ int free_pages = 0;
+ int pages_to_keep = 0; // Of the free pages.
+ Page* last_page_to_keep = top_page;
+ Page* current_page = top_page->next_page();
+ // Loop over the pages to the end of the space.
+ while (current_page->is_valid()) {
+ // Keep every odd-numbered page, one page for every two in the space.
+ if ((free_pages & 0x1) == 1) {
+ pages_to_keep++;
+ last_page_to_keep = last_page_to_keep->next_page();
+ }
+ free_pages++;
+ current_page = current_page->next_page();
+ }
+
+ // Free pages after last_page_to_keep, and adjust the next_page link.
+ Page* p = MemoryAllocator::FreePages(last_page_to_keep->next_page());
+ MemoryAllocator::SetNextPage(last_page_to_keep, p);
+
+ // Since pages are only freed in whole chunks, we may have kept more than
+ // pages_to_keep.
+ while (p->is_valid()) {
+ pages_to_keep++;
+ p = p->next_page();
+ }
+
+ // The difference between free_pages and pages_to_keep is the number of
+ // pages actually freed.
+ ASSERT(pages_to_keep <= free_pages);
+ int bytes_freed = (free_pages - pages_to_keep) * Page::kObjectAreaSize;
+ accounting_stats_.ShrinkSpace(bytes_freed);
+
+ ASSERT(Capacity() == CountTotalPages() * Page::kObjectAreaSize);
+}
+
+
+bool PagedSpace::EnsureCapacity(int capacity) {
+ if (Capacity() >= capacity) return true;
+
+ // Start from the allocation top and loop to the last page in the space.
+ Page* last_page = AllocationTopPage();
+ Page* next_page = last_page->next_page();
+ while (next_page->is_valid()) {
+ last_page = MemoryAllocator::FindLastPageInSameChunk(next_page);
+ next_page = last_page->next_page();
+ }
+
+ // Expand the space until it has the required capacity or expansion fails.
+ do {
+ if (!Expand(last_page)) return false;
+ ASSERT(last_page->next_page()->is_valid());
+ last_page =
+ MemoryAllocator::FindLastPageInSameChunk(last_page->next_page());
+ } while (Capacity() < capacity);
+
+ return true;
+}
+
+
+#ifdef DEBUG
+void PagedSpace::Print() { }
+#endif
+
+
+// -----------------------------------------------------------------------------
+// NewSpace implementation
+
+NewSpace::NewSpace(int initial_semispace_capacity,
+ int maximum_semispace_capacity) {
+ ASSERT(initial_semispace_capacity <= maximum_semispace_capacity);
+ ASSERT(IsPowerOf2(maximum_semispace_capacity));
+ maximum_capacity_ = maximum_semispace_capacity;
+ capacity_ = initial_semispace_capacity;
+ to_space_ = new SemiSpace(capacity_, maximum_capacity_);
+ from_space_ = new SemiSpace(capacity_, maximum_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
+}
+
+
+bool NewSpace::Setup(Address start, int size) {
+ ASSERT(size == 2 * maximum_capacity_);
+ ASSERT(IsAddressAligned(start, size, 0));
+
+ if (to_space_ == NULL
+ || !to_space_->Setup(start, maximum_capacity_)) {
+ return false;
+ }
+ if (from_space_ == NULL
+ || !from_space_->Setup(start + maximum_capacity_, maximum_capacity_)) {
+ return false;
+ }
+
+ start_ = start;
+ address_mask_ = ~(size - 1);
+ object_mask_ = address_mask_ | kHeapObjectTag;
+ object_expected_ = reinterpret_cast<uint32_t>(start) | kHeapObjectTag;
+
+ allocation_info_.top = to_space_->low();
+ allocation_info_.limit = to_space_->high();
+ mc_forwarding_info_.top = NULL;
+ mc_forwarding_info_.limit = NULL;
+
+ ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
+ return true;
+}
+
+
+void NewSpace::TearDown() {
+#if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING)
+ if (allocated_histogram_) {
+ DeleteArray(allocated_histogram_);
+ allocated_histogram_ = NULL;
+ }
+ if (promoted_histogram_) {
+ DeleteArray(promoted_histogram_);
+ promoted_histogram_ = NULL;
+ }
+#endif
+
+ start_ = NULL;
+ capacity_ = 0;
+ allocation_info_.top = NULL;
+ allocation_info_.limit = NULL;
+ mc_forwarding_info_.top = NULL;
+ mc_forwarding_info_.limit = NULL;
+
+ if (to_space_ != NULL) {
+ to_space_->TearDown();
+ delete to_space_;
+ to_space_ = NULL;
+ }
+
+ if (from_space_ != NULL) {
+ from_space_->TearDown();
+ delete from_space_;
+ from_space_ = NULL;
+ }
+}
+
+
+void NewSpace::Flip() {
+ SemiSpace* tmp = from_space_;
+ from_space_ = to_space_;
+ to_space_ = tmp;
+}
+
+
+bool NewSpace::Double() {
+ ASSERT(capacity_ <= maximum_capacity_ / 2);
+ // TODO(1240712): Failure to double the from space can result in
+ // semispaces of different sizes. In the event of that failure, the
+ // to space doubling should be rolled back before returning false.
+ if (!to_space_->Double() || !from_space_->Double()) return false;
+ capacity_ *= 2;
+ allocation_info_.limit = to_space_->high();
+ ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
+ return true;
+}
+
+
+void NewSpace::ResetAllocationInfo() {
+ allocation_info_.top = to_space_->low();
+ allocation_info_.limit = to_space_->high();
+ ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
+}
+
+
+void NewSpace::MCResetRelocationInfo() {
+ mc_forwarding_info_.top = from_space_->low();
+ mc_forwarding_info_.limit = from_space_->high();
+ ASSERT_SEMISPACE_ALLOCATION_INFO(mc_forwarding_info_, from_space_);
+}
+
+
+void NewSpace::MCCommitRelocationInfo() {
+ // Assumes that the spaces have been flipped so that mc_forwarding_info_ is
+ // valid allocation info for the to space.
+ allocation_info_.top = mc_forwarding_info_.top;
+ allocation_info_.limit = to_space_->high();
+ ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
+}
+
+
+#ifdef DEBUG
+// We do not use the SemispaceIterator because verification doesn't assume
+// that it works (it depends on the invariants we are checking).
+void NewSpace::Verify() {
+ // The allocation pointer should be in the space or at the very end.
+ ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
+
+ // There should be objects packed in from the low address up to the
+ // allocation pointer.
+ Address current = to_space_->low();
+ while (current < top()) {
+ HeapObject* object = HeapObject::FromAddress(current);
+
+ // The first word should be a map, and we expect all map pointers to
+ // be in map space.
+ Map* map = object->map();
+ ASSERT(map->IsMap());
+ ASSERT(Heap::map_space()->Contains(map));
+
+ // The object should not be code or a map.
+ ASSERT(!object->IsMap());
+ ASSERT(!object->IsCode());
+
+ // The object itself should look OK.
+ object->Verify();
+
+ // All the interior pointers should be contained in the heap.
+ VerifyPointersVisitor visitor;
+ int size = object->Size();
+ object->IterateBody(map->instance_type(), size, &visitor);
+
+ current += size;
+ }
+
+ // The allocation pointer should not be in the middle of an object.
+ ASSERT(current == top());
+}
+#endif
+
+
+// -----------------------------------------------------------------------------
+// SemiSpace implementation
+
+SemiSpace::SemiSpace(int initial_capacity, int maximum_capacity)
+ : capacity_(initial_capacity), maximum_capacity_(maximum_capacity),
+ start_(NULL), age_mark_(NULL) {
+}
+
+
+bool SemiSpace::Setup(Address start, int size) {
+ ASSERT(size == maximum_capacity_);
+ if (!MemoryAllocator::CommitBlock(start, capacity_)) return false;
+
+ start_ = start;
+ address_mask_ = ~(size - 1);
+ object_mask_ = address_mask_ | kHeapObjectTag;
+ object_expected_ = reinterpret_cast<uint32_t>(start) | kHeapObjectTag;
+
+ age_mark_ = start_;
+ return true;
+}
+
+
+void SemiSpace::TearDown() {
+ start_ = NULL;
+ capacity_ = 0;
+}
+
+
+bool SemiSpace::Double() {
+ if (!MemoryAllocator::CommitBlock(high(), capacity_)) return false;
+ capacity_ *= 2;
+ return true;
+}
+
+
+#ifdef DEBUG
+void SemiSpace::Print() { }
+#endif
+
+
+// -----------------------------------------------------------------------------
+// SemiSpaceIterator implementation.
+SemiSpaceIterator::SemiSpaceIterator(NewSpace* space) {
+ Initialize(space, space->bottom(), space->top(), NULL);
+}
+
+
+SemiSpaceIterator::SemiSpaceIterator(NewSpace* space,
+ HeapObjectCallback size_func) {
+ Initialize(space, space->bottom(), space->top(), size_func);
+}
+
+
+SemiSpaceIterator::SemiSpaceIterator(NewSpace* space, Address start) {
+ Initialize(space, start, space->top(), NULL);
+}
+
+
+void SemiSpaceIterator::Initialize(NewSpace* space, Address start,
+ Address end,
+ HeapObjectCallback size_func) {
+ ASSERT(space->ToSpaceContains(start));
+ ASSERT(space->ToSpaceLow() <= end
+ && end <= space->ToSpaceHigh());
+ space_ = space->to_space_;
+ current_ = start;
+ limit_ = end;
+ size_func_ = size_func;
+}
+
+
+#ifdef DEBUG
+// A static array of histogram info for each type.
+static HistogramInfo heap_histograms[LAST_TYPE+1];
+static JSObject::SpillInformation js_spill_information;
+
+// heap_histograms is shared, always clear it before using it.
+static void ClearHistograms() {
+ // We reset the name each time, though it hasn't changed.
+#define DEF_TYPE_NAME(name) heap_histograms[name].set_name(#name);
+ INSTANCE_TYPE_LIST(DEF_TYPE_NAME)
+#undef DEF_TYPE_NAME
+
+#define CLEAR_HISTOGRAM(name) heap_histograms[name].clear();
+ INSTANCE_TYPE_LIST(CLEAR_HISTOGRAM)
+#undef CLEAR_HISTOGRAM
+
+ js_spill_information.Clear();
+}
+
+
+static int code_kind_statistics[Code::NUMBER_OF_KINDS];
+
+
+static void ClearCodeKindStatistics() {
+ for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) {
+ code_kind_statistics[i] = 0;
+ }
+}
+
+
+static void ReportCodeKindStatistics() {
+ const char* table[Code::NUMBER_OF_KINDS];
+
+#define CASE(name) \
+ case Code::name: table[Code::name] = #name; \
+ break
+
+ for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) {
+ switch (static_cast<Code::Kind>(i)) {
+ CASE(FUNCTION);
+ CASE(STUB);
+ CASE(BUILTIN);
+ CASE(LOAD_IC);
+ CASE(KEYED_LOAD_IC);
+ CASE(STORE_IC);
+ CASE(KEYED_STORE_IC);
+ CASE(CALL_IC);
+ }
+ }
+
+#undef CASE
+
+ PrintF("\n Code kind histograms: \n");
+ for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) {
+ if (code_kind_statistics[i] > 0) {
+ PrintF(" %-20s: %10d bytes\n", table[i], code_kind_statistics[i]);
+ }
+ }
+ PrintF("\n");
+}
+
+
+static int CollectHistogramInfo(HeapObject* obj) {
+ InstanceType type = obj->map()->instance_type();
+ ASSERT(0 <= type && type <= LAST_TYPE);
+ ASSERT(heap_histograms[type].name() != NULL);
+ heap_histograms[type].increment_number(1);
+ heap_histograms[type].increment_bytes(obj->Size());
+
+ if (FLAG_collect_heap_spill_statistics && obj->IsJSObject()) {
+ JSObject::cast(obj)->IncrementSpillStatistics(&js_spill_information);
+ }
+
+ return obj->Size();
+}
+
+
+static void ReportHistogram(bool print_spill) {
+ PrintF("\n Object Histogram:\n");
+ for (int i = 0; i <= LAST_TYPE; i++) {
+ if (heap_histograms[i].number() > 0) {
+ PrintF(" %-33s%10d (%10d bytes)\n",
+ heap_histograms[i].name(),
+ heap_histograms[i].number(),
+ heap_histograms[i].bytes());
+ }
+ }
+ PrintF("\n");
+
+ // Summarize string types.
+ int string_number = 0;
+ int string_bytes = 0;
+#define INCREMENT(type, size, name) \
+ string_number += heap_histograms[type].number(); \
+ string_bytes += heap_histograms[type].bytes();
+ STRING_TYPE_LIST(INCREMENT)
+#undef INCREMENT
+ if (string_number > 0) {
+ PrintF(" %-33s%10d (%10d bytes)\n\n", "STRING_TYPE", string_number,
+ string_bytes);
+ }
+
+ if (FLAG_collect_heap_spill_statistics && print_spill) {
+ js_spill_information.Print();
+ }
+}
+#endif // DEBUG
+
+
+// Support for statistics gathering for --heap-stats and --log-gc.
+#if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING)
+void NewSpace::ClearHistograms() {
+ for (int i = 0; i <= LAST_TYPE; i++) {
+ allocated_histogram_[i].clear();
+ promoted_histogram_[i].clear();
+ }
+}
+
+// Because the copying collector does not touch garbage objects, we iterate
+// the new space before a collection to get a histogram of allocated objects.
+// This only happens (1) when compiled with DEBUG and the --heap-stats flag is
+// set, or when compiled with ENABLE_LOGGING_AND_PROFILING and the --log-gc
+// flag is set.
+void NewSpace::CollectStatistics() {
+ ClearHistograms();
+ SemiSpaceIterator it(this);
+ while (it.has_next()) RecordAllocation(it.next());
+}
+
+
+#ifdef ENABLE_LOGGING_AND_PROFILING
+static void DoReportStatistics(HistogramInfo* info, const char* description) {
+ LOG(HeapSampleBeginEvent("NewSpace", description));
+ // Lump all the string types together.
+ int string_number = 0;
+ int string_bytes = 0;
+#define INCREMENT(type, size, name) \
+ string_number += info[type].number(); \
+ string_bytes += info[type].bytes();
+ STRING_TYPE_LIST(INCREMENT)
+#undef INCREMENT
+ if (string_number > 0) {
+ LOG(HeapSampleItemEvent("STRING_TYPE", string_number, string_bytes));
+ }
+
+ // Then do the other types.
+ for (int i = FIRST_NONSTRING_TYPE; i <= LAST_TYPE; ++i) {
+ if (info[i].number() > 0) {
+ LOG(HeapSampleItemEvent(info[i].name(), info[i].number(),
+ info[i].bytes()));
+ }
+ }
+ LOG(HeapSampleEndEvent("NewSpace", description));
+}
+#endif // ENABLE_LOGGING_AND_PROFILING
+
+
+void NewSpace::ReportStatistics() {
+#ifdef DEBUG
+ if (FLAG_heap_stats) {
+ float pct = static_cast<float>(Available()) / Capacity();
+ PrintF(" capacity: %d, available: %d, %%%d\n",
+ Capacity(), Available(), static_cast<int>(pct*100));
+ PrintF("\n Object Histogram:\n");
+ for (int i = 0; i <= LAST_TYPE; i++) {
+ if (allocated_histogram_[i].number() > 0) {
+ PrintF(" %-33s%10d (%10d bytes)\n",
+ allocated_histogram_[i].name(),
+ allocated_histogram_[i].number(),
+ allocated_histogram_[i].bytes());
+ }
+ }
+ PrintF("\n");
+ }
+#endif // DEBUG
+
+#ifdef ENABLE_LOGGING_AND_PROFILING
+ if (FLAG_log_gc) {
+ DoReportStatistics(allocated_histogram_, "allocated");
+ DoReportStatistics(promoted_histogram_, "promoted");
+ }
+#endif // ENABLE_LOGGING_AND_PROFILING
+}
+
+
+void NewSpace::RecordAllocation(HeapObject* obj) {
+ InstanceType type = obj->map()->instance_type();
+ ASSERT(0 <= type && type <= LAST_TYPE);
+ allocated_histogram_[type].increment_number(1);
+ allocated_histogram_[type].increment_bytes(obj->Size());
+}
+
+
+void NewSpace::RecordPromotion(HeapObject* obj) {
+ InstanceType type = obj->map()->instance_type();
+ ASSERT(0 <= type && type <= LAST_TYPE);
+ promoted_histogram_[type].increment_number(1);
+ promoted_histogram_[type].increment_bytes(obj->Size());
+}
+#endif // defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING)
+
+
+// -----------------------------------------------------------------------------
+// Free lists for old object spaces implementation
+
+void FreeListNode::set_size(int size_in_bytes) {
+ ASSERT(size_in_bytes > 0);
+ ASSERT(IsAligned(size_in_bytes, kPointerSize));
+
+ // We write a map and possibly size information to the block. If the block
+ // is big enough to be a ByteArray with at least one extra word (the next
+ // pointer), we set its map to be the byte array map and its size to an
+ // appropriate array length for the desired size from HeapObject::Size().
+ // If the block is too small (eg, one or two words), to hold both a size
+ // field and a next pointer, we give it a filler map that gives it the
+ // correct size.
+ if (size_in_bytes > Array::kHeaderSize) {
+ set_map(Heap::byte_array_map());
+ ByteArray::cast(this)->set_length(ByteArray::LengthFor(size_in_bytes));
+ } else if (size_in_bytes == kPointerSize) {
+ set_map(Heap::one_word_filler_map());
+ } else if (size_in_bytes == 2 * kPointerSize) {
+ set_map(Heap::two_word_filler_map());
+ } else {
+ UNREACHABLE();
+ }
+}
+
+
+Address FreeListNode::next() {
+ ASSERT(map() == Heap::byte_array_map());
+ return Memory::Address_at(address() + kNextOffset);
+}
+
+
+void FreeListNode::set_next(Address next) {
+ ASSERT(map() == Heap::byte_array_map());
+ Memory::Address_at(address() + kNextOffset) = next;
+}
+
+
+OldSpaceFreeList::OldSpaceFreeList(AllocationSpace owner) : owner_(owner) {
+ Reset();
+}
+
+
+void OldSpaceFreeList::Reset() {
+ available_ = 0;
+ for (int i = 0; i < kFreeListsLength; i++) {
+ free_[i].head_node_ = NULL;
+ }
+ needs_rebuild_ = false;
+ finger_ = kHead;
+ free_[kHead].next_size_ = kEnd;
+}
+
+
+void OldSpaceFreeList::RebuildSizeList() {
+ ASSERT(needs_rebuild_);
+ int cur = kHead;
+ for (int i = cur + 1; i < kFreeListsLength; i++) {
+ if (free_[i].head_node_ != NULL) {
+ free_[cur].next_size_ = i;
+ cur = i;
+ }
+ }
+ free_[cur].next_size_ = kEnd;
+ needs_rebuild_ = false;
+}
+
+
+int OldSpaceFreeList::Free(Address start, int size_in_bytes) {
+#ifdef DEBUG
+ for (int i = 0; i < size_in_bytes; i += kPointerSize) {
+ Memory::Address_at(start + i) = kZapValue;
+ }
+#endif
+ FreeListNode* node = FreeListNode::FromAddress(start);
+ node->set_size(size_in_bytes);
+
+ // Early return to drop too-small blocks on the floor (one or two word
+ // blocks cannot hold a map pointer, a size field, and a pointer to the
+ // next block in the free list).
+ if (size_in_bytes < kMinBlockSize) {
+ return size_in_bytes;
+ }
+
+ // Insert other blocks at the head of an exact free list.
+ int index = size_in_bytes >> kPointerSizeLog2;
+ node->set_next(free_[index].head_node_);
+ free_[index].head_node_ = node->address();
+ available_ += size_in_bytes;
+ needs_rebuild_ = true;
+ return 0;
+}
+
+
+Object* OldSpaceFreeList::Allocate(int size_in_bytes, int* wasted_bytes) {
+ ASSERT(0 < size_in_bytes);
+ ASSERT(size_in_bytes <= kMaxBlockSize);
+ ASSERT(IsAligned(size_in_bytes, kPointerSize));
+
+ if (needs_rebuild_) RebuildSizeList();
+ int index = size_in_bytes >> kPointerSizeLog2;
+ // Check for a perfect fit.
+ if (free_[index].head_node_ != NULL) {
+ FreeListNode* node = FreeListNode::FromAddress(free_[index].head_node_);
+ // If this was the last block of its size, remove the size.
+ if ((free_[index].head_node_ = node->next()) == NULL) RemoveSize(index);
+ available_ -= size_in_bytes;
+ *wasted_bytes = 0;
+ return node;
+ }
+ // Search the size list for the best fit.
+ int prev = finger_ < index ? finger_ : kHead;
+ int cur = FindSize(index, &prev);
+ ASSERT(index < cur);
+ if (cur == kEnd) {
+ // No large enough size in list.
+ *wasted_bytes = 0;
+ return Failure::RetryAfterGC(size_in_bytes, owner_);
+ }
+ int rem = cur - index;
+ int rem_bytes = rem << kPointerSizeLog2;
+ FreeListNode* cur_node = FreeListNode::FromAddress(free_[cur].head_node_);
+ 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;
+}
+
+
+MapSpaceFreeList::MapSpaceFreeList() {
+ Reset();
+}
+
+
+void MapSpaceFreeList::Reset() {
+ available_ = 0;
+ head_ = NULL;
+}
+
+
+void MapSpaceFreeList::Free(Address start) {
+#ifdef DEBUG
+ for (int i = 0; i < Map::kSize; i += kPointerSize) {
+ Memory::Address_at(start + i) = kZapValue;
+ }
+#endif
+ FreeListNode* node = FreeListNode::FromAddress(start);
+ node->set_size(Map::kSize);
+ node->set_next(head_);
+ head_ = node->address();
+ available_ += Map::kSize;
+}
+
+
+Object* MapSpaceFreeList::Allocate() {
+ if (head_ == NULL) {
+ return Failure::RetryAfterGC(Map::kSize, MAP_SPACE);
+ }
+
+ FreeListNode* node = FreeListNode::FromAddress(head_);
+ head_ = node->next();
+ available_ -= Map::kSize;
+ return node;
+}
+
+
+// -----------------------------------------------------------------------------
+// OldSpace implementation
+
+void OldSpace::PrepareForMarkCompact(bool will_compact) {
+ if (will_compact) {
+ // Reset relocation info. During a compacting collection, everything in
+ // the space is considered 'available' and we will rediscover live data
+ // and waste during the collection.
+ MCResetRelocationInfo();
+ mc_end_of_relocation_ = bottom();
+ ASSERT(Available() == Capacity());
+ } else {
+ // During a non-compacting collection, everything below the linear
+ // allocation pointer is considered allocated (everything above is
+ // available) and we will rediscover available and wasted bytes during
+ // the collection.
+ accounting_stats_.AllocateBytes(free_list_.available());
+ accounting_stats_.FillWastedBytes(Waste());
+ }
+
+ // Clear the free list and switch to linear allocation if we are in FREE_LIST
+ free_list_.Reset();
+ if (allocation_mode_ == FREE_LIST) allocation_mode_ = LINEAR;
+}
+
+
+void OldSpace::MCAdjustRelocationEnd(Address address, int size_in_bytes) {
+ ASSERT(Contains(address));
+ Address current_top = mc_end_of_relocation_;
+ Page* current_page = Page::FromAllocationTop(current_top);
+
+ // No more objects relocated to this page? Move to the next.
+ ASSERT(current_top <= current_page->mc_relocation_top);
+ if (current_top == current_page->mc_relocation_top) {
+ // The space should already be properly expanded.
+ Page* next_page = current_page->next_page();
+ CHECK(next_page->is_valid());
+ mc_end_of_relocation_ = next_page->ObjectAreaStart();
+ }
+ ASSERT(mc_end_of_relocation_ == address);
+ mc_end_of_relocation_ += size_in_bytes;
+}
+
+
+void OldSpace::MCCommitRelocationInfo() {
+ // Update fast allocation info.
+ allocation_info_.top = mc_forwarding_info_.top;
+ allocation_info_.limit = mc_forwarding_info_.limit;
+ ASSERT_PAGED_ALLOCATION_INFO(allocation_info_);
+
+ // 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());
+}
+
+
+Object* OldSpace::AllocateRawInternal(int size_in_bytes,
+ AllocationInfo* alloc_info) {
+ ASSERT(HasBeenSetup());
+
+ if (allocation_mode_ == LINEAR_ONLY || allocation_mode_ == LINEAR) {
+ // Try linear allocation in the current page.
+ Address cur_top = alloc_info->top;
+ Address new_top = cur_top + size_in_bytes;
+ if (new_top <= alloc_info->limit) {
+ Object* obj = HeapObject::FromAddress(cur_top);
+ alloc_info->top = new_top;
+ ASSERT_PAGED_ALLOCATION_INFO(*alloc_info);
+
+ accounting_stats_.AllocateBytes(size_in_bytes);
+ ASSERT(Size() <= Capacity());
+ return obj;
+ }
+ } else {
+ // For now we should not try free list allocation during m-c relocation.
+ ASSERT(alloc_info == &allocation_info_);
+ int wasted_bytes;
+ Object* object = free_list_.Allocate(size_in_bytes, &wasted_bytes);
+ accounting_stats_.WasteBytes(wasted_bytes);
+ if (!object->IsFailure()) {
+ accounting_stats_.AllocateBytes(size_in_bytes);
+ return object;
+ }
+ }
+ // Fast allocation failed.
+ return SlowAllocateRaw(size_in_bytes, alloc_info);
+}
+
+
+// Slow cases for AllocateRawInternal. In linear allocation mode, try
+// to allocate in the next page in the space. If there are no more
+// pages, switch to free-list allocation if permitted, otherwise try
+// to grow the space. In free-list allocation mode, try to grow the
+// space and switch to linear allocation.
+Object* OldSpace::SlowAllocateRaw(int size_in_bytes,
+ AllocationInfo* alloc_info) {
+ if (allocation_mode_ == LINEAR_ONLY || allocation_mode_ == LINEAR) {
+ Page* top_page = TopPageOf(*alloc_info);
+ // Until we implement free-list allocation during global gc, we have two
+ // cases: one for normal allocation and one for m-c relocation allocation.
+ if (alloc_info == &allocation_info_) { // Normal allocation.
+ int free_size = top_page->ObjectAreaEnd() - alloc_info->top;
+ // Add the extra space at the top of this page to the free list.
+ if (free_size > 0) {
+ int wasted_bytes = free_list_.Free(alloc_info->top, free_size);
+ accounting_stats_.WasteBytes(wasted_bytes);
+ alloc_info->top += free_size;
+ ASSERT_PAGED_ALLOCATION_INFO(*alloc_info);
+ }
+
+ // Move to the next page in this space if there is one; switch
+ // to free-list allocation, if we can; try to expand the space otherwise
+ if (top_page->next_page()->is_valid()) {
+ SetAllocationInfo(alloc_info, top_page->next_page());
+ } else if (allocation_mode_ == LINEAR) {
+ allocation_mode_ = FREE_LIST;
+ } else if (Expand(top_page)) {
+ ASSERT(top_page->next_page()->is_valid());
+ SetAllocationInfo(alloc_info, top_page->next_page());
+ } else {
+ return Failure::RetryAfterGC(size_in_bytes, identity());
+ }
+ } else { // Allocation during m-c relocation.
+ // During m-c 'allocation' while computing forwarding addresses, we do
+ // not yet add blocks to the free list because they still contain live
+ // objects. We also cache the m-c forwarding allocation pointer in the
+ // current page.
+
+ // If there are no more pages try to expand the space. This can only
+ // happen when promoting objects from the new space.
+ if (!top_page->next_page()->is_valid()) {
+ if (!Expand(top_page)) {
+ return Failure::RetryAfterGC(size_in_bytes, identity());
+ }
+ }
+
+ // Move to the next page.
+ ASSERT(top_page->next_page()->is_valid());
+ top_page->mc_relocation_top = alloc_info->top;
+ SetAllocationInfo(alloc_info, top_page->next_page());
+ }
+ } else { // Free-list allocation.
+ // We failed to allocate from the free list; try to expand the space and
+ // switch back to linear allocation.
+ ASSERT(alloc_info == &allocation_info_);
+ Page* top_page = TopPageOf(*alloc_info);
+ if (!top_page->next_page()->is_valid()) {
+ if (!Expand(top_page)) {
+ return Failure::RetryAfterGC(size_in_bytes, identity());
+ }
+ }
+
+ // We surely have more pages, move to the next page and switch to linear
+ // allocation.
+ ASSERT(top_page->next_page()->is_valid());
+ SetAllocationInfo(alloc_info, top_page->next_page());
+ ASSERT(allocation_mode_ == FREE_LIST);
+ allocation_mode_ = LINEAR;
+ }
+
+ // Perform the allocation.
+ return AllocateRawInternal(size_in_bytes, alloc_info);
+}
+
+
+#ifdef DEBUG
+// We do not assume that the PageIterator works, because it depends on the
+// invariants we are checking during verification.
+void OldSpace::Verify() {
+ // The allocation pointer should be valid, and it should be in a page in the
+ // space.
+ ASSERT_PAGED_ALLOCATION_INFO(allocation_info_);
+ Page* top_page = Page::FromAllocationTop(allocation_info_.top);
+ ASSERT(MemoryAllocator::IsPageInSpace(top_page, this));
+
+ // Loop over all the pages.
+ bool above_allocation_top = false;
+ Page* current_page = first_page_;
+ while (current_page->is_valid()) {
+ if (above_allocation_top) {
+ // We don't care what's above the allocation top.
+ } else {
+ // Unless this is the last page in the space containing allocated
+ // objects, the allocation top should be at the object area end.
+ Address top = current_page->AllocationTop();
+ if (current_page == top_page) {
+ ASSERT(top == allocation_info_.top);
+ // The next page will be above the allocation top.
+ above_allocation_top = true;
+ } else {
+ ASSERT(top == current_page->ObjectAreaEnd());
+ }
+
+ // It should be packed with objects from the bottom to the top.
+ Address current = current_page->ObjectAreaStart();
+ while (current < top) {
+ HeapObject* object = HeapObject::FromAddress(current);
+
+ // The first word should be a map, and we expect all map pointers to
+ // be in map space.
+ Map* map = object->map();
+ ASSERT(map->IsMap());
+ ASSERT(Heap::map_space()->Contains(map));
+
+ // The object should not be a map.
+ ASSERT(!object->IsMap());
+
+ // The object itself should look OK.
+ // This is blocked by bug #1006953.
+ // object->Verify();
+
+ // All the interior pointers should be contained in the heap and have
+ // their remembered set bits set if they point to new space. Code
+ // objects do not have remembered set bits that we care about.
+ VerifyPointersAndRSetVisitor rset_visitor;
+ VerifyPointersVisitor no_rset_visitor;
+ int size = object->Size();
+ if (object->IsCode()) {
+ Code::cast(object)->ConvertICTargetsFromAddressToObject();
+ object->IterateBody(map->instance_type(), size, &no_rset_visitor);
+ Code::cast(object)->ConvertICTargetsFromObjectToAddress();
+ } else {
+ object->IterateBody(map->instance_type(), size, &rset_visitor);
+ }
+
+ current += size;
+ }
+
+ // The allocation pointer should not be in the middle of an object.
+ ASSERT(current == top);
+ }
+
+ current_page = current_page->next_page();
+ }
+}
+
+
+struct CommentStatistic {
+ const char* comment;
+ int size;
+ int count;
+ void Clear() {
+ comment = NULL;
+ size = 0;
+ count = 0;
+ }
+};
+
+
+// must be small, since an iteration is used for lookup
+const int kMaxComments = 64;
+static CommentStatistic comments_statistics[kMaxComments+1];
+
+
+void PagedSpace::ReportCodeStatistics() {
+ ReportCodeKindStatistics();
+ PrintF("Code comment statistics (\" [ comment-txt : size/ "
+ "count (average)\"):\n");
+ for (int i = 0; i <= kMaxComments; i++) {
+ const CommentStatistic& cs = comments_statistics[i];
+ if (cs.size > 0) {
+ PrintF(" %-30s: %10d/%6d (%d)\n", cs.comment, cs.size, cs.count,
+ cs.size/cs.count);
+ }
+ }
+ PrintF("\n");
+}
+
+
+void PagedSpace::ResetCodeStatistics() {
+ ClearCodeKindStatistics();
+ for (int i = 0; i < kMaxComments; i++) comments_statistics[i].Clear();
+ comments_statistics[kMaxComments].comment = "Unknown";
+ comments_statistics[kMaxComments].size = 0;
+ comments_statistics[kMaxComments].count = 0;
+}
+
+
+// Adds comment to 'comment_statistics' table. Performance OK sa long as
+// 'kMaxComments' is small
+static void EnterComment(const char* comment, int delta) {
+ // Do not count empty comments
+ if (delta <= 0) return;
+ CommentStatistic* cs = &comments_statistics[kMaxComments];
+ // Search for a free or matching entry in 'comments_statistics': 'cs'
+ // points to result.
+ for (int i = 0; i < kMaxComments; i++) {
+ if (comments_statistics[i].comment == NULL) {
+ cs = &comments_statistics[i];
+ cs->comment = comment;
+ break;
+ } else if (strcmp(comments_statistics[i].comment, comment) == 0) {
+ cs = &comments_statistics[i];
+ break;
+ }
+ }
+ // Update entry for 'comment'
+ cs->size += delta;
+ cs->count += 1;
+}
+
+
+// Call for each nested comment start (start marked with '[ xxx', end marked
+// with ']'. RelocIterator 'it' must point to a comment reloc info.
+static void CollectCommentStatistics(RelocIterator* it) {
+ ASSERT(!it->done());
+ ASSERT(it->rinfo()->rmode() == 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() == 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() == comment) {
+ delta += it.rinfo()->pc() - prev_pc;
+ CollectCommentStatistics(&it);
+ prev_pc = it.rinfo()->pc();
+ }
+ it.next();
+ }
+
+ ASSERT(code->instruction_start() <= prev_pc &&
+ prev_pc <= code->relocation_start());
+ delta += code->relocation_start() - prev_pc;
+ EnterComment("NoComment", delta);
+ }
+ }
+}
+
+
+void OldSpace::ReportStatistics() {
+ int pct = Available() * 100 / Capacity();
+ PrintF(" capacity: %d, waste: %d, available: %d, %%%d\n",
+ Capacity(), Waste(), Available(), pct);
+
+ // Report remembered set statistics.
+ int rset_marked_pointers = 0;
+ int rset_marked_arrays = 0;
+ int rset_marked_array_elements = 0;
+ int cross_gen_pointers = 0;
+ int cross_gen_array_elements = 0;
+
+ PageIterator page_it(this, PageIterator::PAGES_IN_USE);
+ while (page_it.has_next()) {
+ Page* p = page_it.next();
+
+ for (Address rset_addr = p->RSetStart();
+ rset_addr < p->RSetEnd();
+ rset_addr += kIntSize) {
+ int rset = Memory::int_at(rset_addr);
+ if (rset != 0) {
+ // Bits were set
+ int intoff = rset_addr - p->address();
+ int bitoff = 0;
+ for (; bitoff < kBitsPerInt; ++bitoff) {
+ if ((rset & (1 << bitoff)) != 0) {
+ int bitpos = intoff*kBitsPerByte + bitoff;
+ Address slot = p->OffsetToAddress(bitpos << kObjectAlignmentBits);
+ Object** obj = reinterpret_cast<Object**>(slot);
+ if (*obj == Heap::fixed_array_map()) {
+ rset_marked_arrays++;
+ FixedArray* fa = FixedArray::cast(HeapObject::FromAddress(slot));
+
+ rset_marked_array_elements += fa->length();
+ // Manually inline FixedArray::IterateBody
+ Address elm_start = slot + FixedArray::kHeaderSize;
+ Address elm_stop = elm_start + fa->length() * kPointerSize;
+ for (Address elm_addr = elm_start;
+ elm_addr < elm_stop; elm_addr += kPointerSize) {
+ // Filter non-heap-object pointers
+ Object** elm_p = reinterpret_cast<Object**>(elm_addr);
+ if (Heap::InNewSpace(*elm_p))
+ cross_gen_array_elements++;
+ }
+ } else {
+ rset_marked_pointers++;
+ if (Heap::InNewSpace(*obj))
+ cross_gen_pointers++;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ pct = rset_marked_pointers == 0 ?
+ 0 : cross_gen_pointers * 100 / rset_marked_pointers;
+ PrintF(" rset-marked pointers %d, to-new-space %d (%%%d)\n",
+ rset_marked_pointers, cross_gen_pointers, pct);
+ PrintF(" rset_marked arrays %d, ", rset_marked_arrays);
+ PrintF(" elements %d, ", rset_marked_array_elements);
+ pct = rset_marked_array_elements == 0 ? 0
+ : cross_gen_array_elements * 100 / rset_marked_array_elements;
+ PrintF(" pointers to new space %d (%%%d)\n", cross_gen_array_elements, pct);
+ PrintF(" total rset-marked bits %d\n",
+ (rset_marked_pointers + rset_marked_arrays));
+ pct = (rset_marked_pointers + rset_marked_array_elements) == 0 ? 0
+ : (cross_gen_pointers + cross_gen_array_elements) * 100 /
+ (rset_marked_pointers + rset_marked_array_elements);
+ PrintF(" total rset pointers %d, true cross generation ones %d (%%%d)\n",
+ (rset_marked_pointers + rset_marked_array_elements),
+ (cross_gen_pointers + cross_gen_array_elements),
+ pct);
+
+ ClearHistograms();
+ HeapObjectIterator obj_it(this);
+ while (obj_it.has_next()) { CollectHistogramInfo(obj_it.next()); }
+ ReportHistogram(true);
+}
+
+
+// Dump the range of remembered set words between [start, end) corresponding
+// to the pointers starting at object_p. The allocation_top is an object
+// pointer which should not be read past. This is important for large object
+// pages, where some bits in the remembered set range do not correspond to
+// allocated addresses.
+static void PrintRSetRange(Address start, Address end, Object** object_p,
+ Address allocation_top) {
+ Address rset_address = start;
+
+ // If the range starts on on odd numbered word (eg, for large object extra
+ // remembered set ranges), print some spaces.
+ if ((reinterpret_cast<uint32_t>(start) / kIntSize) % 2 == 1) {
+ PrintF(" ");
+ }
+
+ // Loop over all the words in the range.
+ while (rset_address < end) {
+ uint32_t rset_word = Memory::uint32_at(rset_address);
+ int bit_position = 0;
+
+ // Loop over all the bits in the word.
+ while (bit_position < kBitsPerInt) {
+ if (object_p == reinterpret_cast<Object**>(allocation_top)) {
+ // Print a bar at the allocation pointer.
+ PrintF("|");
+ } else if (object_p > reinterpret_cast<Object**>(allocation_top)) {
+ // Do not dereference object_p past the allocation pointer.
+ PrintF("#");
+ } else if ((rset_word & (1 << bit_position)) == 0) {
+ // Print a dot for zero bits.
+ PrintF(".");
+ } else if (Heap::InNewSpace(*object_p)) {
+ // Print an X for one bits for pointers to new space.
+ PrintF("X");
+ } else {
+ // Print a circle for one bits for pointers to old space.
+ PrintF("o");
+ }
+
+ // Print a space after every 8th bit except the last.
+ if (bit_position % 8 == 7 && bit_position != (kBitsPerInt - 1)) {
+ PrintF(" ");
+ }
+
+ // Advance to next bit.
+ bit_position++;
+ object_p++;
+ }
+
+ // Print a newline after every odd numbered word, otherwise a space.
+ if ((reinterpret_cast<uint32_t>(rset_address) / kIntSize) % 2 == 1) {
+ PrintF("\n");
+ } else {
+ PrintF(" ");
+ }
+
+ // Advance to next remembered set word.
+ rset_address += kIntSize;
+ }
+}
+
+
+void PagedSpace::DoPrintRSet(const char* space_name) {
+ PageIterator it(this, PageIterator::PAGES_IN_USE);
+ while (it.has_next()) {
+ Page* p = it.next();
+ PrintF("%s page 0x%x:\n", space_name, p);
+ PrintRSetRange(p->RSetStart(), p->RSetEnd(),
+ reinterpret_cast<Object**>(p->ObjectAreaStart()),
+ p->AllocationTop());
+ PrintF("\n");
+ }
+}
+
+
+void OldSpace::PrintRSet() { DoPrintRSet("old"); }
+#endif
+
+// -----------------------------------------------------------------------------
+// MapSpace implementation
+
+void MapSpace::PrepareForMarkCompact(bool will_compact) {
+ if (will_compact) {
+ // Reset relocation info.
+ MCResetRelocationInfo();
+
+ // Initialize map index entry.
+ int page_count = 0;
+ PageIterator it(this, PageIterator::ALL_PAGES);
+ while (it.has_next()) {
+ ASSERT_MAP_PAGE_INDEX(page_count);
+
+ Page* p = it.next();
+ ASSERT(p->mc_page_index == page_count);
+
+ page_addresses_[page_count++] = p->address();
+ }
+
+ // During a compacting collection, everything in the space is considered
+ // 'available' (set by the call to MCResetRelocationInfo) and we will
+ // rediscover live and wasted bytes during the collection.
+ ASSERT(Available() == Capacity());
+ } else {
+ // During a non-compacting collection, everything below the linear
+ // allocation pointer except wasted top-of-page blocks is considered
+ // allocated and we will rediscover available bytes during the
+ // collection.
+ accounting_stats_.AllocateBytes(free_list_.available());
+ }
+
+ // Clear the free list and switch to linear allocation if not already
+ // required.
+ free_list_.Reset();
+ if (allocation_mode_ != LINEAR_ONLY) allocation_mode_ = LINEAR;
+}
+
+
+void MapSpace::MCCommitRelocationInfo() {
+ // Update fast allocation info.
+ allocation_info_.top = mc_forwarding_info_.top;
+ allocation_info_.limit = mc_forwarding_info_.limit;
+ ASSERT_PAGED_ALLOCATION_INFO(allocation_info_);
+
+ // 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());
+}
+
+
+Object* MapSpace::AllocateRawInternal(int size_in_bytes,
+ AllocationInfo* alloc_info) {
+ ASSERT(HasBeenSetup());
+ // When doing free-list allocation, we implicitly assume that we always
+ // allocate a map-sized block.
+ ASSERT(size_in_bytes == Map::kSize);
+
+ if (allocation_mode_ == LINEAR_ONLY || allocation_mode_ == LINEAR) {
+ // Try linear allocation in the current page.
+ Address cur_top = alloc_info->top;
+ Address new_top = cur_top + size_in_bytes;
+ if (new_top <= alloc_info->limit) {
+ Object* obj = HeapObject::FromAddress(cur_top);
+ alloc_info->top = new_top;
+ ASSERT_PAGED_ALLOCATION_INFO(*alloc_info);
+
+ accounting_stats_.AllocateBytes(size_in_bytes);
+ return obj;
+ }
+ } else {
+ // We should not do free list allocation during m-c compaction.
+ ASSERT(alloc_info == &allocation_info_);
+ Object* object = free_list_.Allocate();
+ if (!object->IsFailure()) {
+ accounting_stats_.AllocateBytes(size_in_bytes);
+ return object;
+ }
+ }
+ // Fast allocation failed.
+ return SlowAllocateRaw(size_in_bytes, alloc_info);
+}
+
+
+// Slow case for AllocateRawInternal. In linear allocation mode, try to
+// allocate in the next page in the space. If there are no more pages, switch
+// to free-list allocation. In free-list allocation mode, try to grow the
+// space and switch to linear allocation.
+Object* MapSpace::SlowAllocateRaw(int size_in_bytes,
+ AllocationInfo* alloc_info) {
+ if (allocation_mode_ == LINEAR_ONLY || allocation_mode_ == LINEAR) {
+ Page* top_page = TopPageOf(*alloc_info);
+
+ // We do not do free-list allocation during compacting GCs.
+ if (alloc_info == &mc_forwarding_info_) {
+ // We expect to always have more pages, because the map space cannot
+ // grow during GC. Move to the next page.
+ CHECK(top_page->next_page()->is_valid());
+ top_page->mc_relocation_top = alloc_info->top;
+ SetAllocationInfo(alloc_info, top_page->next_page());
+ } else { // Normal allocation.
+ // Move to the next page in this space (counting the top-of-page block
+ // as waste) if there is one, otherwise switch to free-list allocation if
+ // permitted, otherwise try to expand the heap
+ if (top_page->next_page()->is_valid() ||
+ (allocation_mode_ == LINEAR_ONLY && Expand(top_page))) {
+ int free_size = top_page->ObjectAreaEnd() - alloc_info->top;
+ ASSERT(free_size == kPageExtra);
+ accounting_stats_.WasteBytes(free_size);
+ SetAllocationInfo(alloc_info, top_page->next_page());
+ } else if (allocation_mode_ == LINEAR) {
+ allocation_mode_ = FREE_LIST;
+ } else {
+ return Failure::RetryAfterGC(size_in_bytes, MAP_SPACE);
+ }
+ }
+ } else { // Free-list allocation.
+ ASSERT(alloc_info == &allocation_info_);
+ // We failed to allocate from the free list (ie, it must be empty) so try
+ // to expand the space and switch back to linear allocation.
+ Page* top_page = TopPageOf(*alloc_info);
+ if (!top_page->next_page()->is_valid()) {
+ if (!Expand(top_page)) {
+ return Failure::RetryAfterGC(size_in_bytes, MAP_SPACE);
+ }
+ }
+
+ // We have more pages now so we can move to the next and switch to linear
+ // allocation.
+ ASSERT(top_page->next_page()->is_valid());
+ int free_size = top_page->ObjectAreaEnd() - alloc_info->top;
+ ASSERT(free_size == kPageExtra);
+ accounting_stats_.WasteBytes(free_size);
+ SetAllocationInfo(alloc_info, top_page->next_page());
+ ASSERT(allocation_mode_ == FREE_LIST);
+ allocation_mode_ = LINEAR;
+ }
+
+ // Perform the allocation.
+ return AllocateRawInternal(size_in_bytes, alloc_info);
+}
+
+
+#ifdef DEBUG
+// We do not assume that the PageIterator works, because it depends on the
+// invariants we are checking during verification.
+void MapSpace::Verify() {
+ // The allocation pointer should be valid, and it should be in a page in the
+ // space.
+ ASSERT_PAGED_ALLOCATION_INFO(allocation_info_);
+ Page* top_page = Page::FromAllocationTop(allocation_info_.top);
+ ASSERT(MemoryAllocator::IsPageInSpace(top_page, this));
+
+ // Loop over all the pages.
+ bool above_allocation_top = false;
+ Page* current_page = first_page_;
+ while (current_page->is_valid()) {
+ if (above_allocation_top) {
+ // We don't care what's above the allocation top.
+ } else {
+ // Unless this is the last page in the space containing allocated
+ // objects, the allocation top should be at a constant offset from the
+ // object area end.
+ Address top = current_page->AllocationTop();
+ if (current_page == top_page) {
+ ASSERT(top == allocation_info_.top);
+ // The next page will be above the allocation top.
+ above_allocation_top = true;
+ } else {
+ ASSERT(top == current_page->ObjectAreaEnd() - kPageExtra);
+ }
+
+ // It should be packed with objects from the bottom to the top.
+ Address current = current_page->ObjectAreaStart();
+ while (current < top) {
+ HeapObject* object = HeapObject::FromAddress(current);
+
+ // The first word should be a map, and we expect all map pointers to
+ // be in map space.
+ Map* map = object->map();
+ ASSERT(map->IsMap());
+ ASSERT(Heap::map_space()->Contains(map));
+
+ // The object should be a map or a byte array.
+ ASSERT(object->IsMap() || object->IsByteArray());
+
+ // The object itself should look OK.
+ // This is blocked by bug #1006953.
+ // object->Verify();
+
+ // All the interior pointers should be contained in the heap and
+ // have their remembered set bits set if they point to new space.
+ VerifyPointersAndRSetVisitor visitor;
+ int size = object->Size();
+ object->IterateBody(map->instance_type(), size, &visitor);
+
+ current += size;
+ }
+
+ // The allocation pointer should not be in the middle of an object.
+ ASSERT(current == top);
+ }
+
+ current_page = current_page->next_page();
+ }
+}
+
+
+void MapSpace::ReportStatistics() {
+ int pct = Available() * 100 / Capacity();
+ PrintF(" capacity: %d, waste: %d, available: %d, %%%d\n",
+ Capacity(), Waste(), Available(), pct);
+
+ // Report remembered set statistics.
+ int rset_marked_pointers = 0;
+ int cross_gen_pointers = 0;
+
+ PageIterator page_it(this, PageIterator::PAGES_IN_USE);
+ while (page_it.has_next()) {
+ Page* p = page_it.next();
+
+ for (Address rset_addr = p->RSetStart();
+ rset_addr < p->RSetEnd();
+ rset_addr += kIntSize) {
+ int rset = Memory::int_at(rset_addr);
+ if (rset != 0) {
+ // Bits were set
+ int intoff = rset_addr - p->address();
+ int bitoff = 0;
+ for (; bitoff < kBitsPerInt; ++bitoff) {
+ if ((rset & (1 << bitoff)) != 0) {
+ int bitpos = intoff*kBitsPerByte + bitoff;
+ Address slot = p->OffsetToAddress(bitpos << kObjectAlignmentBits);
+ Object** obj = reinterpret_cast<Object**>(slot);
+ rset_marked_pointers++;
+ if (Heap::InNewSpace(*obj))
+ cross_gen_pointers++;
+ }
+ }
+ }
+ }
+ }
+
+ pct = rset_marked_pointers == 0 ?
+ 0 : cross_gen_pointers * 100 / rset_marked_pointers;
+ PrintF(" rset-marked pointers %d, to-new-space %d (%%%d)\n",
+ rset_marked_pointers, cross_gen_pointers, pct);
+
+ ClearHistograms();
+ HeapObjectIterator obj_it(this);
+ while (obj_it.has_next()) { CollectHistogramInfo(obj_it.next()); }
+ ReportHistogram(false);
+}
+
+
+void MapSpace::PrintRSet() { DoPrintRSet("map"); }
+#endif
+
+
+// -----------------------------------------------------------------------------
+// LargeObjectIterator
+
+LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space) {
+ current_ = space->first_chunk_;
+ size_func_ = NULL;
+}
+
+
+LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space,
+ HeapObjectCallback size_func) {
+ current_ = space->first_chunk_;
+ size_func_ = size_func;
+}
+
+
+HeapObject* LargeObjectIterator::next() {
+ ASSERT(has_next());
+ HeapObject* object = current_->GetObject();
+ current_ = current_->next();
+ return object;
+}
+
+
+// -----------------------------------------------------------------------------
+// LargeObjectChunk
+
+LargeObjectChunk* LargeObjectChunk::New(int size_in_bytes,
+ size_t* chunk_size) {
+ size_t requested = ChunkSizeFor(size_in_bytes);
+ void* mem = MemoryAllocator::AllocateRawMemory(requested, chunk_size);
+ 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()
+ : 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;
+}
+
+
+Object* LargeObjectSpace::AllocateRawInternal(int requested_size,
+ int object_size) {
+ ASSERT(0 < object_size && object_size <= requested_size);
+ size_t chunk_size;
+ LargeObjectChunk* chunk =
+ LargeObjectChunk::New(requested_size, &chunk_size);
+ if (chunk == NULL) {
+ return Failure::RetryAfterGC(requested_size, LO_SPACE);
+ }
+
+ 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::AllocateRaw(int size_in_bytes) {
+ ASSERT(0 < size_in_bytes);
+ return AllocateRawInternal(size_in_bytes, size_in_bytes);
+}
+
+
+Object* LargeObjectSpace::AllocateRawFixedArray(int size_in_bytes) {
+ int extra_rset_bytes = ExtraRSetBytesFor(size_in_bytes);
+ return AllocateRawInternal(size_in_bytes + extra_rset_bytes, size_in_bytes);
+}
+
+
+// GC support
+Object* LargeObjectSpace::FindObject(Address a) {
+ for (LargeObjectChunk* chunk = first_chunk_;
+ chunk != NULL;
+ chunk = chunk->next()) {
+ Address chunk_address = chunk->address();
+ if (chunk_address <= a && a < chunk_address + chunk->size()) {
+ return chunk->GetObject();
+ }
+ }
+ return Failure::Exception();
+}
+
+
+void LargeObjectSpace::ClearRSet() {
+ ASSERT(Page::is_rset_in_use());
+
+ LargeObjectIterator it(this);
+ while (it.has_next()) {
+ HeapObject* object = it.next();
+ // We only have code, sequential strings, or fixed arrays in large
+ // object space, and only fixed arrays need remembered set support.
+ if (object->IsFixedArray()) {
+ // Clear the normal remembered set region of the page;
+ Page* page = Page::FromAddress(object->address());
+ page->ClearRSet();
+
+ // Clear the extra remembered set.
+ int size = object->Size();
+ int extra_rset_bytes = ExtraRSetBytesFor(size);
+ memset(object->address() + size, 0, extra_rset_bytes);
+ }
+ }
+}
+
+
+void LargeObjectSpace::IterateRSet(ObjectSlotCallback copy_object_func) {
+ ASSERT(Page::is_rset_in_use());
+
+ LargeObjectIterator it(this);
+ while (it.has_next()) {
+ // We only have code, sequential strings, or fixed arrays in large
+ // object space, and only fixed arrays can possibly contain pointers to
+ // the young generation.
+ HeapObject* object = it.next();
+ if (object->IsFixedArray()) {
+ // Iterate the normal page remembered set range.
+ Page* page = Page::FromAddress(object->address());
+ Address object_end = object->address() + object->Size();
+ Heap::IterateRSetRange(page->ObjectAreaStart(),
+ Min(page->ObjectAreaEnd(), object_end),
+ page->RSetStart(),
+ copy_object_func);
+
+ // Iterate the extra array elements.
+ if (object_end > page->ObjectAreaEnd()) {
+ Heap::IterateRSetRange(page->ObjectAreaEnd(), object_end,
+ object_end, copy_object_func);
+ }
+ }
+ }
+}
+
+
+void LargeObjectSpace::FreeUnmarkedObjects() {
+ LargeObjectChunk* previous = NULL;
+ LargeObjectChunk* current = first_chunk_;
+ while (current != NULL) {
+ HeapObject* object = current->GetObject();
+ if (is_marked(object)) {
+ clear_mark(object);
+ previous = current;
+ current = current->next();
+ } else {
+ Address chunk_address = current->address();
+ size_t chunk_size = current->size();
+
+ // Cut the chunk out from the chunk list.
+ current = current->next();
+ if (previous == NULL) {
+ first_chunk_ = current;
+ } else {
+ previous->set_next(current);
+ }
+
+ // Free the chunk.
+ if (object->IsCode()) {
+ LOG(CodeDeleteEvent(object->address()));
+ }
+ size_ -= chunk_size;
+ page_count_--;
+ MemoryAllocator::FreeRawMemory(chunk_address, chunk_size);
+ LOG(DeleteEvent("LargeObjectChunk", chunk_address));
+ }
+ }
+}
+
+
+bool LargeObjectSpace::Contains(HeapObject* object) {
+ Address address = object->address();
+ Page* page = Page::FromAddress(address);
+
+ SLOW_ASSERT(!page->IsLargeObjectPage()
+ || !FindObject(address)->IsFailure());
+
+ return page->IsLargeObjectPage();
+}
+
+
+#ifdef DEBUG
+// We do not assume that the large object iterator works, because it depends
+// on the invariants we are checking during verification.
+void LargeObjectSpace::Verify() {
+ for (LargeObjectChunk* chunk = first_chunk_;
+ chunk != NULL;
+ chunk = chunk->next()) {
+ // Each chunk contains an object that starts at the large object page's
+ // object area start.
+ HeapObject* object = chunk->GetObject();
+ Page* page = Page::FromAddress(object->address());
+ ASSERT(object->address() == page->ObjectAreaStart());
+
+ // The first word should be a map, and we expect all map pointers to be
+ // in map space.
+ Map* map = object->map();
+ ASSERT(map->IsMap());
+ ASSERT(Heap::map_space()->Contains(map));
+
+ // We have only code, sequential strings, fixed arrays, and byte arrays
+ // in large object space.
+ ASSERT(object->IsCode() || object->IsSeqString()
+ || object->IsFixedArray() || object->IsByteArray());
+
+ // The object itself should look OK.
+ // This is blocked by bug #1006953.
+ // object->Verify();
+
+ // Byte arrays and strings don't have interior pointers.
+ if (object->IsCode()) {
+ VerifyPointersVisitor code_visitor;
+ Code::cast(object)->ConvertICTargetsFromAddressToObject();
+ object->IterateBody(map->instance_type(),
+ object->Size(),
+ &code_visitor);
+ Code::cast(object)->ConvertICTargetsFromObjectToAddress();
+ } else if (object->IsFixedArray()) {
+ // We loop over fixed arrays ourselves, rather then using the visitor,
+ // because the visitor doesn't support the start/offset iteration
+ // needed for IsRSetSet.
+ FixedArray* array = FixedArray::cast(object);
+ for (int j = 0; j < array->length(); j++) {
+ Object* element = array->get(j);
+ if (element->IsHeapObject()) {
+ HeapObject* element_object = HeapObject::cast(element);
+ ASSERT(Heap::Contains(element_object));
+ ASSERT(element_object->map()->IsMap());
+ if (Heap::InNewSpace(element_object)) {
+ ASSERT(Page::IsRSetSet(object->address(),
+ FixedArray::kHeaderSize + j * kPointerSize));
+ }
+ }
+ }
+ }
+ }
+}
+
+
+void LargeObjectSpace::Print() {
+ LargeObjectIterator it(this);
+ while (it.has_next()) {
+ it.next()->Print();
+ }
+}
+
+
+void LargeObjectSpace::ReportStatistics() {
+ PrintF(" size: %d\n", size_);
+ int num_objects = 0;
+ ClearHistograms();
+ LargeObjectIterator it(this);
+ while (it.has_next()) {
+ num_objects++;
+ CollectHistogramInfo(it.next());
+ }
+
+ PrintF(" number of objects %d\n", num_objects);
+ if (num_objects > 0) ReportHistogram(false);
+}
+
+
+void LargeObjectSpace::CollectCodeStatistics() {
+ LargeObjectIterator obj_it(this);
+ while (obj_it.has_next()) {
+ HeapObject* obj = obj_it.next();
+ if (obj->IsCode()) {
+ Code* code = Code::cast(obj);
+ code_kind_statistics[code->kind()] += code->Size();
+ }
+ }
+}
+
+
+void LargeObjectSpace::PrintRSet() {
+ LargeObjectIterator it(this);
+ while (it.has_next()) {
+ HeapObject* object = it.next();
+ if (object->IsFixedArray()) {
+ Page* page = Page::FromAddress(object->address());
+
+ Address allocation_top = object->address() + object->Size();
+ PrintF("large page 0x%x:\n", page);
+ PrintRSetRange(page->RSetStart(), page->RSetEnd(),
+ reinterpret_cast<Object**>(object->address()),
+ allocation_top);
+ int extra_array_bytes = object->Size() - Page::kObjectAreaSize;
+ int extra_rset_bits = RoundUp(extra_array_bytes / kPointerSize,
+ kBitsPerInt);
+ PrintF("------------------------------------------------------------"
+ "-----------\n");
+ PrintRSetRange(allocation_top,
+ allocation_top + extra_rset_bits / kBitsPerByte,
+ reinterpret_cast<Object**>(object->address()
+ + Page::kObjectAreaSize),
+ allocation_top);
+ PrintF("\n");
+ }
+ }
+}
+#endif // DEBUG
+
+} } // namespace v8::internal