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Diffstat (limited to 'src/3rdparty/v8/src/spaces.cc')
| -rw-r--r-- | src/3rdparty/v8/src/spaces.cc | 3147 |
1 files changed, 3147 insertions, 0 deletions
diff --git a/src/3rdparty/v8/src/spaces.cc b/src/3rdparty/v8/src/spaces.cc new file mode 100644 index 0000000..eb4fa7d --- /dev/null +++ b/src/3rdparty/v8/src/spaces.cc @@ -0,0 +1,3147 @@ +// Copyright 2006-2010 the V8 project authors. All rights reserved. +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following +// disclaimer in the documentation and/or other materials provided +// with the distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived +// from this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include "v8.h" + +#include "liveobjectlist-inl.h" +#include "macro-assembler.h" +#include "mark-compact.h" +#include "platform.h" + +namespace v8 { +namespace internal { + +// For contiguous spaces, top should be in the space (or at the end) and limit +// should be the end of the space. +#define ASSERT_SEMISPACE_ALLOCATION_INFO(info, space) \ + ASSERT((space).low() <= (info).top \ + && (info).top <= (space).high() \ + && (info).limit == (space).high()) + +// ---------------------------------------------------------------------------- +// HeapObjectIterator + +HeapObjectIterator::HeapObjectIterator(PagedSpace* space) { + Initialize(space->bottom(), space->top(), NULL); +} + + +HeapObjectIterator::HeapObjectIterator(PagedSpace* space, + HeapObjectCallback size_func) { + Initialize(space->bottom(), space->top(), size_func); +} + + +HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start) { + Initialize(start, space->top(), NULL); +} + + +HeapObjectIterator::HeapObjectIterator(PagedSpace* space, Address start, + HeapObjectCallback size_func) { + Initialize(start, space->top(), size_func); +} + + +HeapObjectIterator::HeapObjectIterator(Page* page, + HeapObjectCallback size_func) { + Initialize(page->ObjectAreaStart(), page->AllocationTop(), size_func); +} + + +void HeapObjectIterator::Initialize(Address cur, Address end, + HeapObjectCallback size_f) { + cur_addr_ = cur; + end_addr_ = end; + end_page_ = Page::FromAllocationTop(end); + size_func_ = size_f; + Page* p = Page::FromAllocationTop(cur_addr_); + cur_limit_ = (p == end_page_) ? end_addr_ : p->AllocationTop(); + +#ifdef DEBUG + Verify(); +#endif +} + + +HeapObject* HeapObjectIterator::FromNextPage() { + if (cur_addr_ == end_addr_) return NULL; + + Page* cur_page = Page::FromAllocationTop(cur_addr_); + cur_page = cur_page->next_page(); + ASSERT(cur_page->is_valid()); + + cur_addr_ = cur_page->ObjectAreaStart(); + cur_limit_ = (cur_page == end_page_) ? end_addr_ : cur_page->AllocationTop(); + + if (cur_addr_ == end_addr_) return NULL; + ASSERT(cur_addr_ < cur_limit_); +#ifdef DEBUG + Verify(); +#endif + return FromCurrentPage(); +} + + +#ifdef DEBUG +void HeapObjectIterator::Verify() { + Page* p = Page::FromAllocationTop(cur_addr_); + ASSERT(p == Page::FromAllocationTop(cur_limit_)); + ASSERT(p->Offset(cur_addr_) <= p->Offset(cur_limit_)); +} +#endif + + +// ----------------------------------------------------------------------------- +// PageIterator + +PageIterator::PageIterator(PagedSpace* space, Mode mode) : space_(space) { + prev_page_ = NULL; + switch (mode) { + case PAGES_IN_USE: + stop_page_ = space->AllocationTopPage(); + break; + case PAGES_USED_BY_MC: + stop_page_ = space->MCRelocationTopPage(); + break; + case ALL_PAGES: +#ifdef DEBUG + // Verify that the cached last page in the space is actually the + // last page. + for (Page* p = space->first_page_; p->is_valid(); p = p->next_page()) { + if (!p->next_page()->is_valid()) { + ASSERT(space->last_page_ == p); + } + } +#endif + stop_page_ = space->last_page_; + break; + } +} + + +// ----------------------------------------------------------------------------- +// CodeRange + + +CodeRange::CodeRange() + : code_range_(NULL), + free_list_(0), + allocation_list_(0), + current_allocation_block_index_(0), + isolate_(NULL) { +} + + +bool CodeRange::Setup(const size_t requested) { + ASSERT(code_range_ == NULL); + + code_range_ = new VirtualMemory(requested); + CHECK(code_range_ != NULL); + if (!code_range_->IsReserved()) { + delete code_range_; + code_range_ = NULL; + return false; + } + + // We are sure that we have mapped a block of requested addresses. + ASSERT(code_range_->size() == requested); + LOG(isolate_, NewEvent("CodeRange", code_range_->address(), requested)); + allocation_list_.Add(FreeBlock(code_range_->address(), code_range_->size())); + current_allocation_block_index_ = 0; + return true; +} + + +int CodeRange::CompareFreeBlockAddress(const FreeBlock* left, + const FreeBlock* right) { + // The entire point of CodeRange is that the difference between two + // addresses in the range can be represented as a signed 32-bit int, + // so the cast is semantically correct. + return static_cast<int>(left->start - right->start); +} + + +void CodeRange::GetNextAllocationBlock(size_t requested) { + for (current_allocation_block_index_++; + current_allocation_block_index_ < allocation_list_.length(); + current_allocation_block_index_++) { + if (requested <= allocation_list_[current_allocation_block_index_].size) { + return; // Found a large enough allocation block. + } + } + + // Sort and merge the free blocks on the free list and the allocation list. + free_list_.AddAll(allocation_list_); + allocation_list_.Clear(); + free_list_.Sort(&CompareFreeBlockAddress); + for (int i = 0; i < free_list_.length();) { + FreeBlock merged = free_list_[i]; + i++; + // Add adjacent free blocks to the current merged block. + while (i < free_list_.length() && + free_list_[i].start == merged.start + merged.size) { + merged.size += free_list_[i].size; + i++; + } + if (merged.size > 0) { + allocation_list_.Add(merged); + } + } + free_list_.Clear(); + + for (current_allocation_block_index_ = 0; + current_allocation_block_index_ < allocation_list_.length(); + current_allocation_block_index_++) { + if (requested <= allocation_list_[current_allocation_block_index_].size) { + return; // Found a large enough allocation block. + } + } + + // Code range is full or too fragmented. + V8::FatalProcessOutOfMemory("CodeRange::GetNextAllocationBlock"); +} + + + +void* CodeRange::AllocateRawMemory(const size_t requested, size_t* allocated) { + ASSERT(current_allocation_block_index_ < allocation_list_.length()); + if (requested > allocation_list_[current_allocation_block_index_].size) { + // Find an allocation block large enough. This function call may + // call V8::FatalProcessOutOfMemory if it cannot find a large enough block. + GetNextAllocationBlock(requested); + } + // Commit the requested memory at the start of the current allocation block. + *allocated = RoundUp(requested, Page::kPageSize); + FreeBlock current = allocation_list_[current_allocation_block_index_]; + if (*allocated >= current.size - Page::kPageSize) { + // Don't leave a small free block, useless for a large object or chunk. + *allocated = current.size; + } + ASSERT(*allocated <= current.size); + if (!code_range_->Commit(current.start, *allocated, true)) { + *allocated = 0; + return NULL; + } + allocation_list_[current_allocation_block_index_].start += *allocated; + allocation_list_[current_allocation_block_index_].size -= *allocated; + if (*allocated == current.size) { + GetNextAllocationBlock(0); // This block is used up, get the next one. + } + return current.start; +} + + +void CodeRange::FreeRawMemory(void* address, size_t length) { + free_list_.Add(FreeBlock(address, length)); + code_range_->Uncommit(address, length); +} + + +void CodeRange::TearDown() { + delete code_range_; // Frees all memory in the virtual memory range. + code_range_ = NULL; + free_list_.Free(); + allocation_list_.Free(); +} + + +// ----------------------------------------------------------------------------- +// MemoryAllocator +// + +// 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; + + +MemoryAllocator::MemoryAllocator() + : capacity_(0), + capacity_executable_(0), + size_(0), + size_executable_(0), + initial_chunk_(NULL), + chunks_(kEstimatedNumberOfChunks), + free_chunk_ids_(kEstimatedNumberOfChunks), + max_nof_chunks_(0), + top_(0), + isolate_(NULL) { +} + + +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(intptr_t capacity, intptr_t capacity_executable) { + capacity_ = RoundUp(capacity, Page::kPageSize); + capacity_executable_ = RoundUp(capacity_executable, Page::kPageSize); + ASSERT_GE(capacity_, capacity_executable_); + + // Over-estimate the size of chunks_ array. It assumes the expansion of old + // space is always in the unit of a chunk (kChunkSize) except the last + // expansion. + // + // Due to alignment, allocated space might be one page less than required + // number (kPagesPerChunk) of pages for old spaces. + // + // Reserve two chunk ids for semispaces, one for map space, one for old + // space, and one for code space. + max_nof_chunks_ = + static_cast<int>((capacity_ / (kChunkSize - Page::kPageSize))) + 5; + if (max_nof_chunks_ > kMaxNofChunks) return false; + + size_ = 0; + size_executable_ = 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(isolate_, DeleteEvent("InitialChunk", initial_chunk_->address())); + delete initial_chunk_; + initial_chunk_ = NULL; + } + + ASSERT(top_ == max_nof_chunks_); // all chunks are free + top_ = 0; + capacity_ = 0; + capacity_executable_ = 0; + size_ = 0; + max_nof_chunks_ = 0; +} + + +void* MemoryAllocator::AllocateRawMemory(const size_t requested, + size_t* allocated, + Executability executable) { + if (size_ + static_cast<size_t>(requested) > static_cast<size_t>(capacity_)) { + return NULL; + } + + void* mem; + if (executable == EXECUTABLE) { + // Check executable memory limit. + if (size_executable_ + requested > + static_cast<size_t>(capacity_executable_)) { + LOG(isolate_, + StringEvent("MemoryAllocator::AllocateRawMemory", + "V8 Executable Allocation capacity exceeded")); + return NULL; + } + // Allocate executable memory either from code range or from the + // OS. + if (isolate_->code_range()->exists()) { + mem = isolate_->code_range()->AllocateRawMemory(requested, allocated); + } else { + mem = OS::Allocate(requested, allocated, true); + } + // Update executable memory size. + size_executable_ += static_cast<int>(*allocated); + } else { + mem = OS::Allocate(requested, allocated, false); + } + int alloced = static_cast<int>(*allocated); + size_ += alloced; + +#ifdef DEBUG + ZapBlock(reinterpret_cast<Address>(mem), alloced); +#endif + isolate_->counters()->memory_allocated()->Increment(alloced); + return mem; +} + + +void MemoryAllocator::FreeRawMemory(void* mem, + size_t length, + Executability executable) { +#ifdef DEBUG + ZapBlock(reinterpret_cast<Address>(mem), length); +#endif + if (isolate_->code_range()->contains(static_cast<Address>(mem))) { + isolate_->code_range()->FreeRawMemory(mem, length); + } else { + OS::Free(mem, length); + } + isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(length)); + size_ -= static_cast<int>(length); + if (executable == EXECUTABLE) size_executable_ -= static_cast<int>(length); + + ASSERT(size_ >= 0); + ASSERT(size_executable_ >= 0); +} + + +void MemoryAllocator::PerformAllocationCallback(ObjectSpace space, + AllocationAction action, + size_t size) { + for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { + MemoryAllocationCallbackRegistration registration = + memory_allocation_callbacks_[i]; + if ((registration.space & space) == space && + (registration.action & action) == action) + registration.callback(space, action, static_cast<int>(size)); + } +} + + +bool MemoryAllocator::MemoryAllocationCallbackRegistered( + MemoryAllocationCallback callback) { + for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { + if (memory_allocation_callbacks_[i].callback == callback) return true; + } + return false; +} + + +void MemoryAllocator::AddMemoryAllocationCallback( + MemoryAllocationCallback callback, + ObjectSpace space, + AllocationAction action) { + ASSERT(callback != NULL); + MemoryAllocationCallbackRegistration registration(callback, space, action); + ASSERT(!MemoryAllocator::MemoryAllocationCallbackRegistered(callback)); + return memory_allocation_callbacks_.Add(registration); +} + + +void MemoryAllocator::RemoveMemoryAllocationCallback( + MemoryAllocationCallback callback) { + ASSERT(callback != NULL); + for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) { + if (memory_allocation_callbacks_[i].callback == callback) { + memory_allocation_callbacks_.Remove(i); + return; + } + } + UNREACHABLE(); +} + +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(isolate_, + NewEvent("InitialChunk", initial_chunk_->address(), requested)); + size_ += static_cast<int>(requested); + return initial_chunk_->address(); +} + + +static int PagesInChunk(Address start, size_t size) { + // The first page starts on the first page-aligned address from start onward + // and the last page ends on the last page-aligned address before + // start+size. Page::kPageSize is a power of two so we can divide by + // shifting. + return static_cast<int>((RoundDown(start + size, Page::kPageSize) + - RoundUp(start, Page::kPageSize)) >> kPageSizeBits); +} + + +Page* MemoryAllocator::AllocatePages(int requested_pages, + int* allocated_pages, + PagedSpace* owner) { + if (requested_pages <= 0) return Page::FromAddress(NULL); + size_t chunk_size = requested_pages * Page::kPageSize; + + void* chunk = AllocateRawMemory(chunk_size, &chunk_size, owner->executable()); + if (chunk == NULL) return Page::FromAddress(NULL); + LOG(isolate_, NewEvent("PagedChunk", chunk, chunk_size)); + + *allocated_pages = PagesInChunk(static_cast<Address>(chunk), chunk_size); + // We may 'lose' a page due to alignment. + ASSERT(*allocated_pages >= kPagesPerChunk - 1); + if (*allocated_pages == 0) { + FreeRawMemory(chunk, chunk_size, owner->executable()); + LOG(isolate_, DeleteEvent("PagedChunk", chunk)); + return Page::FromAddress(NULL); + } + + int chunk_id = Pop(); + chunks_[chunk_id].init(static_cast<Address>(chunk), chunk_size, owner); + + ObjectSpace space = static_cast<ObjectSpace>(1 << owner->identity()); + PerformAllocationCallback(space, kAllocationActionAllocate, chunk_size); + Page* new_pages = InitializePagesInChunk(chunk_id, *allocated_pages, owner); + + return new_pages; +} + + +Page* MemoryAllocator::CommitPages(Address start, size_t size, + PagedSpace* owner, int* num_pages) { + ASSERT(start != NULL); + *num_pages = PagesInChunk(start, size); + ASSERT(*num_pages > 0); + ASSERT(initial_chunk_ != NULL); + ASSERT(InInitialChunk(start)); + ASSERT(InInitialChunk(start + size - 1)); + if (!initial_chunk_->Commit(start, size, owner->executable() == EXECUTABLE)) { + return Page::FromAddress(NULL); + } +#ifdef DEBUG + ZapBlock(start, size); +#endif + isolate_->counters()->memory_allocated()->Increment(static_cast<int>(size)); + + // So long as we correctly overestimated the number of chunks we should not + // run out of chunk ids. + CHECK(!OutOfChunkIds()); + int chunk_id = Pop(); + chunks_[chunk_id].init(start, size, owner); + return InitializePagesInChunk(chunk_id, *num_pages, owner); +} + + +bool MemoryAllocator::CommitBlock(Address start, + size_t size, + Executability executable) { + ASSERT(start != NULL); + ASSERT(size > 0); + ASSERT(initial_chunk_ != NULL); + ASSERT(InInitialChunk(start)); + ASSERT(InInitialChunk(start + size - 1)); + + if (!initial_chunk_->Commit(start, size, executable)) return false; +#ifdef DEBUG + ZapBlock(start, size); +#endif + isolate_->counters()->memory_allocated()->Increment(static_cast<int>(size)); + return true; +} + + +bool MemoryAllocator::UncommitBlock(Address start, size_t size) { + ASSERT(start != NULL); + ASSERT(size > 0); + ASSERT(initial_chunk_ != NULL); + ASSERT(InInitialChunk(start)); + ASSERT(InInitialChunk(start + size - 1)); + + if (!initial_chunk_->Uncommit(start, size)) return false; + isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size)); + return true; +} + + +void MemoryAllocator::ZapBlock(Address start, size_t size) { + for (size_t s = 0; s + kPointerSize <= size; s += kPointerSize) { + Memory::Address_at(start + s) = kZapValue; + } +} + + +Page* MemoryAllocator::InitializePagesInChunk(int chunk_id, int pages_in_chunk, + PagedSpace* owner) { + ASSERT(IsValidChunk(chunk_id)); + ASSERT(pages_in_chunk > 0); + + Address chunk_start = chunks_[chunk_id].address(); + + Address low = RoundUp(chunk_start, Page::kPageSize); + +#ifdef DEBUG + size_t chunk_size = chunks_[chunk_id].size(); + Address high = RoundDown(chunk_start + chunk_size, Page::kPageSize); + ASSERT(pages_in_chunk <= + ((OffsetFrom(high) - OffsetFrom(low)) / Page::kPageSize)); +#endif + + Address page_addr = low; + for (int i = 0; i < pages_in_chunk; i++) { + Page* p = Page::FromAddress(page_addr); + p->heap_ = owner->heap(); + p->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id; + p->InvalidateWatermark(true); + p->SetIsLargeObjectPage(false); + p->SetAllocationWatermark(p->ObjectAreaStart()); + p->SetCachedAllocationWatermark(p->ObjectAreaStart()); + page_addr += Page::kPageSize; + } + + // Set the next page of the last page to 0. + Page* last_page = Page::FromAddress(page_addr - Page::kPageSize); + last_page->opaque_header = OffsetFrom(0) | chunk_id; + + return Page::FromAddress(low); +} + + +Page* MemoryAllocator::FreePages(Page* p) { + if (!p->is_valid()) return p; + + // Find the first page in the same chunk as 'p' + Page* first_page = FindFirstPageInSameChunk(p); + Page* page_to_return = Page::FromAddress(NULL); + + if (p != first_page) { + // Find the last page in the same chunk as 'prev'. + Page* last_page = FindLastPageInSameChunk(p); + first_page = GetNextPage(last_page); // first page in next chunk + + // set the next_page of last_page to NULL + SetNextPage(last_page, Page::FromAddress(NULL)); + page_to_return = p; // return 'p' when exiting + } + + while (first_page->is_valid()) { + int chunk_id = GetChunkId(first_page); + ASSERT(IsValidChunk(chunk_id)); + + // Find the first page of the next chunk before deleting this chunk. + first_page = GetNextPage(FindLastPageInSameChunk(first_page)); + + // Free the current chunk. + DeleteChunk(chunk_id); + } + + return page_to_return; +} + + +void MemoryAllocator::FreeAllPages(PagedSpace* space) { + for (int i = 0, length = chunks_.length(); i < length; i++) { + if (chunks_[i].owner() == space) { + DeleteChunk(i); + } + } +} + + +void MemoryAllocator::DeleteChunk(int chunk_id) { + ASSERT(IsValidChunk(chunk_id)); + + ChunkInfo& c = chunks_[chunk_id]; + + // We cannot free a chunk contained in the initial chunk because it was not + // allocated with AllocateRawMemory. Instead we uncommit the virtual + // memory. + if (InInitialChunk(c.address())) { + // TODO(1240712): VirtualMemory::Uncommit has a return value which + // is ignored here. + initial_chunk_->Uncommit(c.address(), c.size()); + Counters* counters = isolate_->counters(); + counters->memory_allocated()->Decrement(static_cast<int>(c.size())); + } else { + LOG(isolate_, DeleteEvent("PagedChunk", c.address())); + ObjectSpace space = static_cast<ObjectSpace>(1 << c.owner_identity()); + size_t size = c.size(); + FreeRawMemory(c.address(), size, c.executable()); + PerformAllocationCallback(space, kAllocationActionFree, 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: %" V8_PTR_PREFIX "d" + ", used: %" V8_PTR_PREFIX "d" + ", available: %%%d\n\n", + capacity_, size_, static_cast<int>(pct*100)); +} +#endif + + +void MemoryAllocator::RelinkPageListInChunkOrder(PagedSpace* space, + Page** first_page, + Page** last_page, + Page** last_page_in_use) { + Page* first = NULL; + Page* last = NULL; + + for (int i = 0, length = chunks_.length(); i < length; i++) { + ChunkInfo& chunk = chunks_[i]; + + if (chunk.owner() == space) { + if (first == NULL) { + Address low = RoundUp(chunk.address(), Page::kPageSize); + first = Page::FromAddress(low); + } + last = RelinkPagesInChunk(i, + chunk.address(), + chunk.size(), + last, + last_page_in_use); + } + } + + if (first_page != NULL) { + *first_page = first; + } + + if (last_page != NULL) { + *last_page = last; + } +} + + +Page* MemoryAllocator::RelinkPagesInChunk(int chunk_id, + Address chunk_start, + size_t chunk_size, + Page* prev, + Page** last_page_in_use) { + Address page_addr = RoundUp(chunk_start, Page::kPageSize); + int pages_in_chunk = PagesInChunk(chunk_start, chunk_size); + + if (prev->is_valid()) { + SetNextPage(prev, Page::FromAddress(page_addr)); + } + + for (int i = 0; i < pages_in_chunk; i++) { + Page* p = Page::FromAddress(page_addr); + p->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id; + page_addr += Page::kPageSize; + + p->InvalidateWatermark(true); + if (p->WasInUseBeforeMC()) { + *last_page_in_use = p; + } + } + + // Set the next page of the last page to 0. + Page* last_page = Page::FromAddress(page_addr - Page::kPageSize); + last_page->opaque_header = OffsetFrom(0) | chunk_id; + + if (last_page->WasInUseBeforeMC()) { + *last_page_in_use = last_page; + } + + return last_page; +} + + +// ----------------------------------------------------------------------------- +// PagedSpace implementation + +PagedSpace::PagedSpace(Heap* heap, + intptr_t max_capacity, + AllocationSpace id, + Executability executable) + : Space(heap, id, executable) { + max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize) + * Page::kObjectAreaSize; + accounting_stats_.Clear(); + + allocation_info_.top = NULL; + allocation_info_.limit = NULL; + + mc_forwarding_info_.top = NULL; + mc_forwarding_info_.limit = NULL; +} + + +bool PagedSpace::Setup(Address start, size_t size) { + if (HasBeenSetup()) return false; + + int num_pages = 0; + // Try to use the virtual memory range passed to us. If it is too small to + // contain at least one page, ignore it and allocate instead. + int pages_in_chunk = PagesInChunk(start, size); + if (pages_in_chunk > 0) { + first_page_ = Isolate::Current()->memory_allocator()->CommitPages( + RoundUp(start, Page::kPageSize), + Page::kPageSize * pages_in_chunk, + this, &num_pages); + } else { + int requested_pages = + Min(MemoryAllocator::kPagesPerChunk, + static_cast<int>(max_capacity_ / Page::kObjectAreaSize)); + first_page_ = + Isolate::Current()->memory_allocator()->AllocatePages( + requested_pages, &num_pages, this); + if (!first_page_->is_valid()) return false; + } + + // We are sure that the first page is valid and that we have at least one + // page. + ASSERT(first_page_->is_valid()); + ASSERT(num_pages > 0); + accounting_stats_.ExpandSpace(num_pages * Page::kObjectAreaSize); + ASSERT(Capacity() <= max_capacity_); + + // Sequentially clear region marks in the newly allocated + // pages and cache the current last page in the space. + for (Page* p = first_page_; p->is_valid(); p = p->next_page()) { + p->SetRegionMarks(Page::kAllRegionsCleanMarks); + last_page_ = p; + } + + // Use first_page_ for allocation. + SetAllocationInfo(&allocation_info_, first_page_); + + page_list_is_chunk_ordered_ = true; + + return true; +} + + +bool PagedSpace::HasBeenSetup() { + return (Capacity() > 0); +} + + +void PagedSpace::TearDown() { + Isolate::Current()->memory_allocator()->FreeAllPages(this); + first_page_ = NULL; + accounting_stats_.Clear(); +} + + +#ifdef ENABLE_HEAP_PROTECTION + +void PagedSpace::Protect() { + Page* page = first_page_; + while (page->is_valid()) { + Isolate::Current()->memory_allocator()->ProtectChunkFromPage(page); + page = Isolate::Current()->memory_allocator()-> + FindLastPageInSameChunk(page)->next_page(); + } +} + + +void PagedSpace::Unprotect() { + Page* page = first_page_; + while (page->is_valid()) { + Isolate::Current()->memory_allocator()->UnprotectChunkFromPage(page); + page = Isolate::Current()->memory_allocator()-> + FindLastPageInSameChunk(page)->next_page(); + } +} + +#endif + + +void PagedSpace::MarkAllPagesClean() { + PageIterator it(this, PageIterator::ALL_PAGES); + while (it.has_next()) { + it.next()->SetRegionMarks(Page::kAllRegionsCleanMarks); + } +} + + +MaybeObject* PagedSpace::FindObject(Address addr) { + // Note: this function can only be called before or after mark-compact GC + // because it accesses map pointers. + ASSERT(!heap()->mark_compact_collector()->in_use()); + + if (!Contains(addr)) return Failure::Exception(); + + Page* p = Page::FromAddress(addr); + ASSERT(IsUsed(p)); + Address cur = p->ObjectAreaStart(); + Address end = p->AllocationTop(); + while (cur < end) { + HeapObject* obj = HeapObject::FromAddress(cur); + Address next = cur + obj->Size(); + if ((cur <= addr) && (addr < next)) return obj; + cur = next; + } + + UNREACHABLE(); + return Failure::Exception(); +} + + +bool PagedSpace::IsUsed(Page* page) { + PageIterator it(this, PageIterator::PAGES_IN_USE); + while (it.has_next()) { + if (page == it.next()) return true; + } + return false; +} + + +void PagedSpace::SetAllocationInfo(AllocationInfo* alloc_info, Page* p) { + alloc_info->top = p->ObjectAreaStart(); + alloc_info->limit = p->ObjectAreaEnd(); + ASSERT(alloc_info->VerifyPagedAllocation()); +} + + +void PagedSpace::MCResetRelocationInfo() { + // Set page indexes. + int i = 0; + PageIterator it(this, PageIterator::ALL_PAGES); + while (it.has_next()) { + Page* p = it.next(); + p->mc_page_index = i++; + } + + // Set mc_forwarding_info_ to the first page in the space. + SetAllocationInfo(&mc_forwarding_info_, first_page_); + // All the bytes in the space are 'available'. We will rediscover + // allocated and wasted bytes during GC. + accounting_stats_.Reset(); +} + + +int PagedSpace::MCSpaceOffsetForAddress(Address addr) { +#ifdef DEBUG + // The Contains function considers the address at the beginning of a + // page in the page, MCSpaceOffsetForAddress considers it is in the + // previous page. + if (Page::IsAlignedToPageSize(addr)) { + ASSERT(Contains(addr - kPointerSize)); + } else { + ASSERT(Contains(addr)); + } +#endif + + // If addr is at the end of a page, it belongs to previous page + Page* p = Page::IsAlignedToPageSize(addr) + ? Page::FromAllocationTop(addr) + : Page::FromAddress(addr); + int index = p->mc_page_index; + return (index * Page::kPageSize) + p->Offset(addr); +} + + +// Slow case for reallocating and promoting objects during a compacting +// collection. This function is not space-specific. +HeapObject* PagedSpace::SlowMCAllocateRaw(int size_in_bytes) { + Page* current_page = TopPageOf(mc_forwarding_info_); + if (!current_page->next_page()->is_valid()) { + if (!Expand(current_page)) { + return NULL; + } + } + + // There are surely more pages in the space now. + ASSERT(current_page->next_page()->is_valid()); + // We do not add the top of page block for current page to the space's + // free list---the block may contain live objects so we cannot write + // bookkeeping information to it. Instead, we will recover top of page + // blocks when we move objects to their new locations. + // + // We do however write the allocation pointer to the page. The encoding + // of forwarding addresses is as an offset in terms of live bytes, so we + // need quick access to the allocation top of each page to decode + // forwarding addresses. + current_page->SetAllocationWatermark(mc_forwarding_info_.top); + current_page->next_page()->InvalidateWatermark(true); + SetAllocationInfo(&mc_forwarding_info_, current_page->next_page()); + return AllocateLinearly(&mc_forwarding_info_, size_in_bytes); +} + + +bool PagedSpace::Expand(Page* last_page) { + ASSERT(max_capacity_ % Page::kObjectAreaSize == 0); + ASSERT(Capacity() % Page::kObjectAreaSize == 0); + + if (Capacity() == max_capacity_) return false; + + ASSERT(Capacity() < max_capacity_); + // Last page must be valid and its next page is invalid. + ASSERT(last_page->is_valid() && !last_page->next_page()->is_valid()); + + int available_pages = + static_cast<int>((max_capacity_ - Capacity()) / Page::kObjectAreaSize); + // We don't want to have to handle small chunks near the end so if there are + // not kPagesPerChunk pages available without exceeding the max capacity then + // act as if memory has run out. + if (available_pages < MemoryAllocator::kPagesPerChunk) return false; + + int desired_pages = Min(available_pages, MemoryAllocator::kPagesPerChunk); + Page* p = heap()->isolate()->memory_allocator()->AllocatePages( + desired_pages, &desired_pages, this); + if (!p->is_valid()) return false; + + accounting_stats_.ExpandSpace(desired_pages * Page::kObjectAreaSize); + ASSERT(Capacity() <= max_capacity_); + + heap()->isolate()->memory_allocator()->SetNextPage(last_page, p); + + // Sequentially clear region marks of new pages and and cache the + // new last page in the space. + while (p->is_valid()) { + p->SetRegionMarks(Page::kAllRegionsCleanMarks); + last_page_ = p; + p = p->next_page(); + } + + return true; +} + + +#ifdef DEBUG +int PagedSpace::CountTotalPages() { + int count = 0; + for (Page* p = first_page_; p->is_valid(); p = p->next_page()) { + count++; + } + return count; +} +#endif + + +void PagedSpace::Shrink() { + if (!page_list_is_chunk_ordered_) { + // We can't shrink space if pages is not chunk-ordered + // (see comment for class MemoryAllocator for definition). + return; + } + + // Release half of free pages. + Page* top_page = AllocationTopPage(); + ASSERT(top_page->is_valid()); + + // Count the number of pages we would like to free. + int pages_to_free = 0; + for (Page* p = top_page->next_page(); p->is_valid(); p = p->next_page()) { + pages_to_free++; + } + + // Free pages after top_page. + Page* p = heap()->isolate()->memory_allocator()-> + FreePages(top_page->next_page()); + heap()->isolate()->memory_allocator()->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 = heap()->isolate()->memory_allocator()-> + 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 = + heap()->isolate()->memory_allocator()->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(heap()->isolate()->memory_allocator()->IsPageInSpace(top_page, this)); + + // Loop over all the pages. + bool above_allocation_top = false; + Page* current_page = first_page_; + while (current_page->is_valid()) { + if (above_allocation_top) { + // We don't care what's above the allocation top. + } else { + Address top = current_page->AllocationTop(); + if (current_page == top_page) { + ASSERT(top == allocation_info_.top); + // The next page will be above the allocation top. + above_allocation_top = true; + } + + // It should be packed with objects from the bottom to the top. + Address current = current_page->ObjectAreaStart(); + while (current < top) { + HeapObject* object = HeapObject::FromAddress(current); + + // The first word should be a map, and we expect all map pointers to + // be in map space. + Map* map = object->map(); + ASSERT(map->IsMap()); + ASSERT(heap()->map_space()->Contains(map)); + + // Perform space-specific object verification. + VerifyObject(object); + + // The object itself should look OK. + object->Verify(); + + // All the interior pointers should be contained in the heap and + // have page regions covering intergenerational references should be + // marked dirty. + int size = object->Size(); + object->IterateBody(map->instance_type(), size, visitor); + + current += size; + } + + // The allocation pointer should not be in the middle of an object. + ASSERT(current == top); + } + + current_page = current_page->next_page(); + } +} +#endif + + +// ----------------------------------------------------------------------------- +// NewSpace implementation + + +bool NewSpace::Setup(Address start, int size) { + // Setup new space based on the preallocated memory block defined by + // start and size. The provided space is divided into two semi-spaces. + // To support fast containment testing in the new space, the size of + // this chunk must be a power of two and it must be aligned to its size. + int initial_semispace_capacity = heap()->InitialSemiSpaceSize(); + int maximum_semispace_capacity = heap()->MaxSemiSpaceSize(); + + ASSERT(initial_semispace_capacity <= maximum_semispace_capacity); + ASSERT(IsPowerOf2(maximum_semispace_capacity)); + + // Allocate and setup the histogram arrays if necessary. +#if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) + allocated_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1); + promoted_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1); + +#define SET_NAME(name) allocated_histogram_[name].set_name(#name); \ + promoted_histogram_[name].set_name(#name); + INSTANCE_TYPE_LIST(SET_NAME) +#undef SET_NAME +#endif + + ASSERT(size == 2 * heap()->ReservedSemiSpaceSize()); + ASSERT(IsAddressAligned(start, size, 0)); + + if (!to_space_.Setup(start, + initial_semispace_capacity, + maximum_semispace_capacity)) { + return false; + } + if (!from_space_.Setup(start + maximum_semispace_capacity, + initial_semispace_capacity, + maximum_semispace_capacity)) { + return false; + } + + start_ = start; + address_mask_ = ~(size - 1); + object_mask_ = address_mask_ | kHeapObjectTagMask; + object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag; + + allocation_info_.top = to_space_.low(); + allocation_info_.limit = to_space_.high(); + mc_forwarding_info_.top = NULL; + mc_forwarding_info_.limit = NULL; + + ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); + return true; +} + + +void NewSpace::TearDown() { +#if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) + if (allocated_histogram_) { + DeleteArray(allocated_histogram_); + allocated_histogram_ = NULL; + } + if (promoted_histogram_) { + DeleteArray(promoted_histogram_); + promoted_histogram_ = NULL; + } +#endif + + start_ = NULL; + allocation_info_.top = NULL; + allocation_info_.limit = NULL; + mc_forwarding_info_.top = NULL; + mc_forwarding_info_.limit = NULL; + + to_space_.TearDown(); + from_space_.TearDown(); +} + + +#ifdef ENABLE_HEAP_PROTECTION + +void NewSpace::Protect() { + heap()->isolate()->memory_allocator()->Protect(ToSpaceLow(), Capacity()); + heap()->isolate()->memory_allocator()->Protect(FromSpaceLow(), Capacity()); +} + + +void NewSpace::Unprotect() { + heap()->isolate()->memory_allocator()->Unprotect(ToSpaceLow(), Capacity(), + to_space_.executable()); + heap()->isolate()->memory_allocator()->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 * SizeAsInt()); + int rounded_new_capacity = + RoundUp(new_capacity, static_cast<int>(OS::AllocateAlignment())); + if (rounded_new_capacity < Capacity() && + to_space_.ShrinkTo(rounded_new_capacity)) { + // Only shrink from space if we managed to shrink to space. + if (!from_space_.ShrinkTo(rounded_new_capacity)) { + // If we managed to shrink to space but couldn't shrink from + // space, attempt to grow to space again. + if (!to_space_.GrowTo(from_space_.Capacity())) { + // We are in an inconsistent state because we could not + // commit/uncommit memory from new space. + V8::FatalProcessOutOfMemory("Failed to shrink new space."); + } + } + } + allocation_info_.limit = to_space_.high(); + ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); +} + + +void NewSpace::ResetAllocationInfo() { + allocation_info_.top = to_space_.low(); + allocation_info_.limit = to_space_.high(); + ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); +} + + +void NewSpace::MCResetRelocationInfo() { + mc_forwarding_info_.top = from_space_.low(); + mc_forwarding_info_.limit = from_space_.high(); + ASSERT_SEMISPACE_ALLOCATION_INFO(mc_forwarding_info_, from_space_); +} + + +void NewSpace::MCCommitRelocationInfo() { + // Assumes that the spaces have been flipped so that mc_forwarding_info_ is + // valid allocation info for the to space. + allocation_info_.top = mc_forwarding_info_.top; + allocation_info_.limit = to_space_.high(); + ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); +} + + +#ifdef DEBUG +// We do not use the SemispaceIterator because verification doesn't assume +// that it works (it depends on the invariants we are checking). +void NewSpace::Verify() { + // The allocation pointer should be in the space or at the very end. + ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_); + + // There should be objects packed in from the low address up to the + // allocation pointer. + Address current = to_space_.low(); + while (current < top()) { + HeapObject* object = HeapObject::FromAddress(current); + + // The first word should be a map, and we expect all map pointers to + // be in map space. + Map* map = object->map(); + ASSERT(map->IsMap()); + ASSERT(heap()->map_space()->Contains(map)); + + // The object should not be code or a map. + ASSERT(!object->IsMap()); + ASSERT(!object->IsCode()); + + // The object itself should look OK. + object->Verify(); + + // All the interior pointers should be contained in the heap. + VerifyPointersVisitor visitor; + int size = object->Size(); + object->IterateBody(map->instance_type(), size, &visitor); + + current += size; + } + + // The allocation pointer should not be in the middle of an object. + ASSERT(current == top()); +} +#endif + + +bool SemiSpace::Commit() { + ASSERT(!is_committed()); + if (!heap()->isolate()->memory_allocator()->CommitBlock( + start_, capacity_, executable())) { + return false; + } + committed_ = true; + return true; +} + + +bool SemiSpace::Uncommit() { + ASSERT(is_committed()); + if (!heap()->isolate()->memory_allocator()->UncommitBlock( + start_, capacity_)) { + return false; + } + committed_ = false; + return true; +} + + +// ----------------------------------------------------------------------------- +// SemiSpace implementation + +bool SemiSpace::Setup(Address start, + int initial_capacity, + int maximum_capacity) { + // Creates a space in the young generation. The constructor does not + // allocate memory from the OS. A SemiSpace is given a contiguous chunk of + // memory of size 'capacity' when set up, and does not grow or shrink + // otherwise. In the mark-compact collector, the memory region of the from + // space is used as the marking stack. It requires contiguous memory + // addresses. + initial_capacity_ = initial_capacity; + capacity_ = initial_capacity; + maximum_capacity_ = maximum_capacity; + committed_ = false; + + start_ = start; + address_mask_ = ~(maximum_capacity - 1); + object_mask_ = address_mask_ | kHeapObjectTagMask; + object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag; + age_mark_ = start_; + + return Commit(); +} + + +void SemiSpace::TearDown() { + start_ = NULL; + capacity_ = 0; +} + + +bool SemiSpace::Grow() { + // Double the semispace size but only up to maximum capacity. + int maximum_extra = maximum_capacity_ - capacity_; + int extra = Min(RoundUp(capacity_, static_cast<int>(OS::AllocateAlignment())), + maximum_extra); + if (!heap()->isolate()->memory_allocator()->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 (!heap()->isolate()->memory_allocator()->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 (!heap()->isolate()->memory_allocator()->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 +// heap_histograms is shared, always clear it before using it. +static void ClearHistograms() { + Isolate* isolate = Isolate::Current(); + // We reset the name each time, though it hasn't changed. +#define DEF_TYPE_NAME(name) isolate->heap_histograms()[name].set_name(#name); + INSTANCE_TYPE_LIST(DEF_TYPE_NAME) +#undef DEF_TYPE_NAME + +#define CLEAR_HISTOGRAM(name) isolate->heap_histograms()[name].clear(); + INSTANCE_TYPE_LIST(CLEAR_HISTOGRAM) +#undef CLEAR_HISTOGRAM + + isolate->js_spill_information()->Clear(); +} + + +static void ClearCodeKindStatistics() { + Isolate* isolate = Isolate::Current(); + for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) { + isolate->code_kind_statistics()[i] = 0; + } +} + + +static void ReportCodeKindStatistics() { + Isolate* isolate = Isolate::Current(); + const char* table[Code::NUMBER_OF_KINDS] = { NULL }; + +#define CASE(name) \ + case Code::name: table[Code::name] = #name; \ + break + + for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) { + switch (static_cast<Code::Kind>(i)) { + CASE(FUNCTION); + CASE(OPTIMIZED_FUNCTION); + CASE(STUB); + CASE(BUILTIN); + CASE(LOAD_IC); + CASE(KEYED_LOAD_IC); + CASE(KEYED_EXTERNAL_ARRAY_LOAD_IC); + CASE(STORE_IC); + CASE(KEYED_STORE_IC); + CASE(KEYED_EXTERNAL_ARRAY_STORE_IC); + CASE(CALL_IC); + CASE(KEYED_CALL_IC); + CASE(BINARY_OP_IC); + CASE(TYPE_RECORDING_BINARY_OP_IC); + CASE(COMPARE_IC); + } + } + +#undef CASE + + PrintF("\n Code kind histograms: \n"); + for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) { + if (isolate->code_kind_statistics()[i] > 0) { + PrintF(" %-20s: %10d bytes\n", table[i], + isolate->code_kind_statistics()[i]); + } + } + PrintF("\n"); +} + + +static int CollectHistogramInfo(HeapObject* obj) { + Isolate* isolate = Isolate::Current(); + InstanceType type = obj->map()->instance_type(); + ASSERT(0 <= type && type <= LAST_TYPE); + ASSERT(isolate->heap_histograms()[type].name() != NULL); + isolate->heap_histograms()[type].increment_number(1); + isolate->heap_histograms()[type].increment_bytes(obj->Size()); + + if (FLAG_collect_heap_spill_statistics && obj->IsJSObject()) { + JSObject::cast(obj)->IncrementSpillStatistics( + isolate->js_spill_information()); + } + + return obj->Size(); +} + + +static void ReportHistogram(bool print_spill) { + Isolate* isolate = Isolate::Current(); + PrintF("\n Object Histogram:\n"); + for (int i = 0; i <= LAST_TYPE; i++) { + if (isolate->heap_histograms()[i].number() > 0) { + PrintF(" %-34s%10d (%10d bytes)\n", + isolate->heap_histograms()[i].name(), + isolate->heap_histograms()[i].number(), + isolate->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 += isolate->heap_histograms()[type].number(); \ + string_bytes += isolate->heap_histograms()[type].bytes(); + STRING_TYPE_LIST(INCREMENT) +#undef INCREMENT + if (string_number > 0) { + PrintF(" %-34s%10d (%10d bytes)\n\n", "STRING_TYPE", string_number, + string_bytes); + } + + if (FLAG_collect_heap_spill_statistics && print_spill) { + isolate->js_spill_information()->Print(); + } +} +#endif // DEBUG + + +// Support for statistics gathering for --heap-stats and --log-gc. +#if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) +void NewSpace::ClearHistograms() { + for (int i = 0; i <= LAST_TYPE; i++) { + allocated_histogram_[i].clear(); + promoted_histogram_[i].clear(); + } +} + +// Because the copying collector does not touch garbage objects, we iterate +// the new space before a collection to get a histogram of allocated objects. +// This only happens (1) when compiled with DEBUG and the --heap-stats flag is +// set, or when compiled with ENABLE_LOGGING_AND_PROFILING and the --log-gc +// flag is set. +void NewSpace::CollectStatistics() { + ClearHistograms(); + SemiSpaceIterator it(this); + for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) + RecordAllocation(obj); +} + + +#ifdef ENABLE_LOGGING_AND_PROFILING +static void DoReportStatistics(Isolate* isolate, + HistogramInfo* info, const char* description) { + LOG(isolate, 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(isolate, + 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(isolate, + HeapSampleItemEvent(info[i].name(), info[i].number(), + info[i].bytes())); + } + } + LOG(isolate, 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: %" V8_PTR_PREFIX "d" + ", available: %" V8_PTR_PREFIX "d, %%%d\n", + Capacity(), Available(), static_cast<int>(pct*100)); + PrintF("\n Object Histogram:\n"); + for (int i = 0; i <= LAST_TYPE; i++) { + if (allocated_histogram_[i].number() > 0) { + PrintF(" %-34s%10d (%10d bytes)\n", + allocated_histogram_[i].name(), + allocated_histogram_[i].number(), + allocated_histogram_[i].bytes()); + } + } + PrintF("\n"); + } +#endif // DEBUG + +#ifdef ENABLE_LOGGING_AND_PROFILING + if (FLAG_log_gc) { + Isolate* isolate = ISOLATE; + DoReportStatistics(isolate, allocated_histogram_, "allocated"); + DoReportStatistics(isolate, 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(Heap* heap, int size_in_bytes) { + ASSERT(size_in_bytes > 0); + ASSERT(IsAligned(size_in_bytes, kPointerSize)); + + // We write a map and possibly size information to the block. If the block + // is big enough to be a ByteArray with at least one extra word (the next + // pointer), we set its map to be the byte array map and its size to an + // appropriate array length for the desired size from HeapObject::Size(). + // If the block is too small (eg, one or two words), to hold both a size + // field and a next pointer, we give it a filler map that gives it the + // correct size. + if (size_in_bytes > ByteArray::kHeaderSize) { + set_map(heap->raw_unchecked_byte_array_map()); + // Can't use ByteArray::cast because it fails during deserialization. + ByteArray* this_as_byte_array = reinterpret_cast<ByteArray*>(this); + this_as_byte_array->set_length(ByteArray::LengthFor(size_in_bytes)); + } else if (size_in_bytes == kPointerSize) { + set_map(heap->raw_unchecked_one_pointer_filler_map()); + } else if (size_in_bytes == 2 * kPointerSize) { + set_map(heap->raw_unchecked_two_pointer_filler_map()); + } else { + UNREACHABLE(); + } + // We would like to ASSERT(Size() == size_in_bytes) but this would fail during + // deserialization because the byte array map is not done yet. +} + + +Address FreeListNode::next(Heap* heap) { + ASSERT(IsFreeListNode(this)); + if (map() == heap->raw_unchecked_byte_array_map()) { + ASSERT(Size() >= kNextOffset + kPointerSize); + return Memory::Address_at(address() + kNextOffset); + } else { + return Memory::Address_at(address() + kPointerSize); + } +} + + +void FreeListNode::set_next(Heap* heap, Address next) { + ASSERT(IsFreeListNode(this)); + if (map() == heap->raw_unchecked_byte_array_map()) { + ASSERT(Size() >= kNextOffset + kPointerSize); + Memory::Address_at(address() + kNextOffset) = next; + } else { + Memory::Address_at(address() + kPointerSize) = next; + } +} + + +OldSpaceFreeList::OldSpaceFreeList(Heap* heap, AllocationSpace owner) + : heap_(heap), + 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 + Isolate::Current()->memory_allocator()->ZapBlock(start, size_in_bytes); +#endif + FreeListNode* node = FreeListNode::FromAddress(start); + node->set_size(heap_, 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(heap_, free_[index].head_node_); + free_[index].head_node_ = node->address(); + available_ += size_in_bytes; + needs_rebuild_ = true; + return 0; +} + + +MaybeObject* 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(heap_)) == 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(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(heap_)) == NULL) { + free_[rem].next_size_ = free_[cur].next_size_; + } else { + free_[rem].next_size_ = cur; + } + // Add the remainder block. + rem_node->set_size(heap_, rem_bytes); + rem_node->set_next(heap_, 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(heap_)) == NULL) { + finger_ = prev; + free_[prev].next_size_ = free_[cur].next_size_; + } + if (rem_bytes < kMinBlockSize) { + // Too-small remainder is wasted. + rem_node->set_size(heap_, 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(heap_, rem_bytes); + rem_node->set_next(heap_, free_[rem].head_node_); + free_[rem].head_node_ = rem_node->address(); + if (rem_node->next(heap_) == NULL) InsertSize(rem); + } + available_ -= size_in_bytes; + *wasted_bytes = 0; + return cur_node; +} + + +void OldSpaceFreeList::MarkNodes() { + 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); + cur_addr = cur_node->next(heap_); + cur_node->SetMark(); + } + } +} + + +#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(heap_); + } + } + return false; +} +#endif + + +FixedSizeFreeList::FixedSizeFreeList(Heap* heap, + AllocationSpace owner, + int object_size) + : heap_(heap), owner_(owner), object_size_(object_size) { + Reset(); +} + + +void FixedSizeFreeList::Reset() { + available_ = 0; + head_ = tail_ = NULL; +} + + +void FixedSizeFreeList::Free(Address start) { +#ifdef DEBUG + Isolate::Current()->memory_allocator()->ZapBlock(start, object_size_); +#endif + // We only use the freelists with mark-sweep. + ASSERT(!HEAP->mark_compact_collector()->IsCompacting()); + FreeListNode* node = FreeListNode::FromAddress(start); + node->set_size(heap_, object_size_); + node->set_next(heap_, NULL); + if (head_ == NULL) { + tail_ = head_ = node->address(); + } else { + FreeListNode::FromAddress(tail_)->set_next(heap_, node->address()); + tail_ = node->address(); + } + available_ += object_size_; +} + + +MaybeObject* FixedSizeFreeList::Allocate() { + if (head_ == NULL) { + return Failure::RetryAfterGC(owner_); + } + + ASSERT(!FLAG_always_compact); // We only use the freelists with mark-sweep. + FreeListNode* node = FreeListNode::FromAddress(head_); + head_ = node->next(heap_); + available_ -= object_size_; + return node; +} + + +void FixedSizeFreeList::MarkNodes() { + Address cur_addr = head_; + while (cur_addr != NULL && cur_addr != tail_) { + FreeListNode* cur_node = FreeListNode::FromAddress(cur_addr); + cur_addr = cur_node->next(heap_); + cur_node->SetMark(); + } +} + + +// ----------------------------------------------------------------------------- +// OldSpace implementation + +void OldSpace::PrepareForMarkCompact(bool will_compact) { + // Call prepare of the super class. + PagedSpace::PrepareForMarkCompact(will_compact); + + if (will_compact) { + // Reset relocation info. During a compacting collection, everything in + // the space is considered 'available' and we will rediscover live data + // and waste during the collection. + MCResetRelocationInfo(); + ASSERT(Available() == Capacity()); + } else { + // During a non-compacting collection, everything below the linear + // allocation pointer is considered allocated (everything above is + // available) and we will rediscover available and wasted bytes during + // the collection. + accounting_stats_.AllocateBytes(free_list_.available()); + accounting_stats_.FillWastedBytes(Waste()); + } + + // Clear the free list before a full GC---it will be rebuilt afterward. + free_list_.Reset(); +} + + +void OldSpace::MCCommitRelocationInfo() { + // Update fast allocation info. + allocation_info_.top = mc_forwarding_info_.top; + allocation_info_.limit = mc_forwarding_info_.limit; + ASSERT(allocation_info_.VerifyPagedAllocation()); + + // The space is compacted and we haven't yet built free lists or + // wasted any space. + ASSERT(Waste() == 0); + ASSERT(AvailableFree() == 0); + + // Build the free list for the space. + int computed_size = 0; + PageIterator it(this, PageIterator::PAGES_USED_BY_MC); + while (it.has_next()) { + Page* p = it.next(); + // Space below the relocation pointer is allocated. + computed_size += + static_cast<int>(p->AllocationWatermark() - p->ObjectAreaStart()); + if (it.has_next()) { + // Free the space at the top of the page. + int extra_size = + static_cast<int>(p->ObjectAreaEnd() - p->AllocationWatermark()); + if (extra_size > 0) { + int wasted_bytes = free_list_.Free(p->AllocationWatermark(), + extra_size); + // The bytes we have just "freed" to add to the free list were + // already accounted as available. + accounting_stats_.WasteBytes(wasted_bytes); + } + } + } + + // Make sure the computed size - based on the used portion of the pages in + // use - matches the size obtained while computing forwarding addresses. + ASSERT(computed_size == Size()); +} + + +bool NewSpace::ReserveSpace(int bytes) { + // We can't reliably unpack a partial snapshot that needs more new space + // space than the minimum NewSpace size. + ASSERT(bytes <= InitialCapacity()); + Address limit = allocation_info_.limit; + Address top = allocation_info_.top; + return limit - top >= bytes; +} + + +void PagedSpace::FreePages(Page* prev, Page* last) { + if (last == AllocationTopPage()) { + // Pages are already at the end of used pages. + return; + } + + Page* first = NULL; + + // Remove pages from the list. + if (prev == NULL) { + first = first_page_; + first_page_ = last->next_page(); + } else { + first = prev->next_page(); + heap()->isolate()->memory_allocator()->SetNextPage( + prev, last->next_page()); + } + + // Attach it after the last page. + heap()->isolate()->memory_allocator()->SetNextPage(last_page_, first); + last_page_ = last; + heap()->isolate()->memory_allocator()->SetNextPage(last, NULL); + + // Clean them up. + do { + first->InvalidateWatermark(true); + first->SetAllocationWatermark(first->ObjectAreaStart()); + first->SetCachedAllocationWatermark(first->ObjectAreaStart()); + first->SetRegionMarks(Page::kAllRegionsCleanMarks); + first = first->next_page(); + } while (first != NULL); + + // Order of pages in this space might no longer be consistent with + // order of pages in chunks. + page_list_is_chunk_ordered_ = false; +} + + +void PagedSpace::RelinkPageListInChunkOrder(bool deallocate_blocks) { + const bool add_to_freelist = true; + + // Mark used and unused pages to properly fill unused pages + // after reordering. + PageIterator all_pages_iterator(this, PageIterator::ALL_PAGES); + Page* last_in_use = AllocationTopPage(); + bool in_use = true; + + while (all_pages_iterator.has_next()) { + Page* p = all_pages_iterator.next(); + p->SetWasInUseBeforeMC(in_use); + if (p == last_in_use) { + // We passed a page containing allocation top. All consequent + // pages are not used. + in_use = false; + } + } + + if (page_list_is_chunk_ordered_) return; + + Page* new_last_in_use = Page::FromAddress(NULL); + heap()->isolate()->memory_allocator()->RelinkPageListInChunkOrder( + this, &first_page_, &last_page_, &new_last_in_use); + ASSERT(new_last_in_use->is_valid()); + + if (new_last_in_use != last_in_use) { + // Current allocation top points to a page which is now in the middle + // of page list. We should move allocation top forward to the new last + // used page so various object iterators will continue to work properly. + int size_in_bytes = static_cast<int>(PageAllocationLimit(last_in_use) - + last_in_use->AllocationTop()); + + last_in_use->SetAllocationWatermark(last_in_use->AllocationTop()); + if (size_in_bytes > 0) { + Address start = last_in_use->AllocationTop(); + if (deallocate_blocks) { + accounting_stats_.AllocateBytes(size_in_bytes); + DeallocateBlock(start, size_in_bytes, add_to_freelist); + } else { + heap()->CreateFillerObjectAt(start, size_in_bytes); + } + } + + // New last in use page was in the middle of the list before + // sorting so it full. + SetTop(new_last_in_use->AllocationTop()); + + ASSERT(AllocationTopPage() == new_last_in_use); + ASSERT(AllocationTopPage()->WasInUseBeforeMC()); + } + + PageIterator pages_in_use_iterator(this, PageIterator::PAGES_IN_USE); + while (pages_in_use_iterator.has_next()) { + Page* p = pages_in_use_iterator.next(); + if (!p->WasInUseBeforeMC()) { + // Empty page is in the middle of a sequence of used pages. + // Allocate it as a whole and deallocate immediately. + int size_in_bytes = static_cast<int>(PageAllocationLimit(p) - + p->ObjectAreaStart()); + + p->SetAllocationWatermark(p->ObjectAreaStart()); + Address start = p->ObjectAreaStart(); + if (deallocate_blocks) { + accounting_stats_.AllocateBytes(size_in_bytes); + DeallocateBlock(start, size_in_bytes, add_to_freelist); + } else { + heap()->CreateFillerObjectAt(start, size_in_bytes); + } + } + } + + page_list_is_chunk_ordered_ = true; +} + + +void PagedSpace::PrepareForMarkCompact(bool will_compact) { + if (will_compact) { + RelinkPageListInChunkOrder(false); + } +} + + +bool PagedSpace::ReserveSpace(int bytes) { + Address limit = allocation_info_.limit; + Address top = allocation_info_.top; + if (limit - top >= bytes) return true; + + // There wasn't enough space in the current page. Lets put the rest + // of the page on the free list and start a fresh page. + PutRestOfCurrentPageOnFreeList(TopPageOf(allocation_info_)); + + Page* reserved_page = TopPageOf(allocation_info_); + int bytes_left_to_reserve = bytes; + while (bytes_left_to_reserve > 0) { + if (!reserved_page->next_page()->is_valid()) { + if (heap()->OldGenerationAllocationLimitReached()) return false; + Expand(reserved_page); + } + bytes_left_to_reserve -= Page::kPageSize; + reserved_page = reserved_page->next_page(); + if (!reserved_page->is_valid()) return false; + } + ASSERT(TopPageOf(allocation_info_)->next_page()->is_valid()); + TopPageOf(allocation_info_)->next_page()->InvalidateWatermark(true); + SetAllocationInfo(&allocation_info_, + TopPageOf(allocation_info_)->next_page()); + return true; +} + + +// You have to call this last, since the implementation from PagedSpace +// doesn't know that memory was 'promised' to large object space. +bool LargeObjectSpace::ReserveSpace(int bytes) { + return heap()->OldGenerationSpaceAvailable() >= bytes; +} + + +// Slow case for normal allocation. Try in order: (1) allocate in the next +// page in the space, (2) allocate off the space's free list, (3) expand the +// space, (4) fail. +HeapObject* OldSpace::SlowAllocateRaw(int size_in_bytes) { + // Linear allocation in this space has failed. If there is another page + // in the space, move to that page and allocate there. This allocation + // should succeed (size_in_bytes should not be greater than a page's + // object area size). + Page* current_page = TopPageOf(allocation_info_); + if (current_page->next_page()->is_valid()) { + return AllocateInNextPage(current_page, size_in_bytes); + } + + // There is no next page in this space. Try free list allocation unless that + // is currently forbidden. + if (!heap()->linear_allocation()) { + int wasted_bytes; + Object* result; + MaybeObject* maybe = free_list_.Allocate(size_in_bytes, &wasted_bytes); + accounting_stats_.WasteBytes(wasted_bytes); + if (maybe->ToObject(&result)) { + accounting_stats_.AllocateBytes(size_in_bytes); + + HeapObject* obj = HeapObject::cast(result); + Page* p = Page::FromAddress(obj->address()); + + if (obj->address() >= p->AllocationWatermark()) { + // There should be no hole between the allocation watermark + // and allocated object address. + // Memory above the allocation watermark was not swept and + // might contain garbage pointers to new space. + ASSERT(obj->address() == p->AllocationWatermark()); + p->SetAllocationWatermark(obj->address() + size_in_bytes); + } + + return obj; + } + } + + // Free list allocation failed and there is no next page. Fail if we have + // hit the old generation size limit that should cause a garbage + // collection. + if (!heap()->always_allocate() && + heap()->OldGenerationAllocationLimitReached()) { + return NULL; + } + + // Try to expand the space and allocate in the new next page. + ASSERT(!current_page->next_page()->is_valid()); + if (Expand(current_page)) { + return AllocateInNextPage(current_page, size_in_bytes); + } + + // Finally, fail. + return NULL; +} + + +void OldSpace::PutRestOfCurrentPageOnFreeList(Page* current_page) { + current_page->SetAllocationWatermark(allocation_info_.top); + int free_size = + static_cast<int>(current_page->ObjectAreaEnd() - allocation_info_.top); + if (free_size > 0) { + int wasted_bytes = free_list_.Free(allocation_info_.top, free_size); + accounting_stats_.WasteBytes(wasted_bytes); + } +} + + +void FixedSpace::PutRestOfCurrentPageOnFreeList(Page* current_page) { + current_page->SetAllocationWatermark(allocation_info_.top); + int free_size = + static_cast<int>(current_page->ObjectAreaEnd() - allocation_info_.top); + // In the fixed space free list all the free list items have the right size. + // We use up the rest of the page while preserving this invariant. + while (free_size >= object_size_in_bytes_) { + free_list_.Free(allocation_info_.top); + allocation_info_.top += object_size_in_bytes_; + free_size -= object_size_in_bytes_; + accounting_stats_.WasteBytes(object_size_in_bytes_); + } +} + + +// Add the block at the top of the page to the space's free list, set the +// allocation info to the next page (assumed to be one), and allocate +// linearly there. +HeapObject* OldSpace::AllocateInNextPage(Page* current_page, + int size_in_bytes) { + ASSERT(current_page->next_page()->is_valid()); + Page* next_page = current_page->next_page(); + next_page->ClearGCFields(); + PutRestOfCurrentPageOnFreeList(current_page); + SetAllocationInfo(&allocation_info_, next_page); + return AllocateLinearly(&allocation_info_, size_in_bytes); +} + + +void OldSpace::DeallocateBlock(Address start, + int size_in_bytes, + bool add_to_freelist) { + Free(start, size_in_bytes, add_to_freelist); +} + + +#ifdef DEBUG +void PagedSpace::ReportCodeStatistics() { + Isolate* isolate = Isolate::Current(); + CommentStatistic* comments_statistics = + isolate->paged_space_comments_statistics(); + ReportCodeKindStatistics(); + PrintF("Code comment statistics (\" [ comment-txt : size/ " + "count (average)\"):\n"); + for (int i = 0; i <= CommentStatistic::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() { + Isolate* isolate = Isolate::Current(); + CommentStatistic* comments_statistics = + isolate->paged_space_comments_statistics(); + ClearCodeKindStatistics(); + for (int i = 0; i < CommentStatistic::kMaxComments; i++) { + comments_statistics[i].Clear(); + } + comments_statistics[CommentStatistic::kMaxComments].comment = "Unknown"; + comments_statistics[CommentStatistic::kMaxComments].size = 0; + comments_statistics[CommentStatistic::kMaxComments].count = 0; +} + + +// Adds comment to 'comment_statistics' table. Performance OK as long as +// 'kMaxComments' is small +static void EnterComment(Isolate* isolate, const char* comment, int delta) { + CommentStatistic* comments_statistics = + isolate->paged_space_comments_statistics(); + // Do not count empty comments + if (delta <= 0) return; + CommentStatistic* cs = &comments_statistics[CommentStatistic::kMaxComments]; + // Search for a free or matching entry in 'comments_statistics': 'cs' + // points to result. + for (int i = 0; i < CommentStatistic::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(Isolate* isolate, RelocIterator* it) { + ASSERT(!it->done()); + ASSERT(it->rinfo()->rmode() == RelocInfo::COMMENT); + const char* tmp = reinterpret_cast<const char*>(it->rinfo()->data()); + if (tmp[0] != '[') { + // Not a nested comment; skip + return; + } + + // Search for end of nested comment or a new nested comment + const char* const comment_txt = + reinterpret_cast<const char*>(it->rinfo()->data()); + const byte* prev_pc = it->rinfo()->pc(); + int flat_delta = 0; + it->next(); + while (true) { + // All nested comments must be terminated properly, and therefore exit + // from loop. + ASSERT(!it->done()); + if (it->rinfo()->rmode() == RelocInfo::COMMENT) { + const char* const txt = + reinterpret_cast<const char*>(it->rinfo()->data()); + flat_delta += static_cast<int>(it->rinfo()->pc() - prev_pc); + if (txt[0] == ']') break; // End of nested comment + // A new comment + CollectCommentStatistics(isolate, it); + // Skip code that was covered with previous comment + prev_pc = it->rinfo()->pc(); + } + it->next(); + } + EnterComment(isolate, comment_txt, flat_delta); +} + + +// Collects code size statistics: +// - by code kind +// - by code comment +void PagedSpace::CollectCodeStatistics() { + Isolate* isolate = heap()->isolate(); + HeapObjectIterator obj_it(this); + for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) { + if (obj->IsCode()) { + Code* code = Code::cast(obj); + isolate->code_kind_statistics()[code->kind()] += code->Size(); + RelocIterator it(code); + int delta = 0; + const byte* prev_pc = code->instruction_start(); + while (!it.done()) { + if (it.rinfo()->rmode() == RelocInfo::COMMENT) { + delta += static_cast<int>(it.rinfo()->pc() - prev_pc); + CollectCommentStatistics(isolate, &it); + prev_pc = it.rinfo()->pc(); + } + it.next(); + } + + ASSERT(code->instruction_start() <= prev_pc && + prev_pc <= code->instruction_end()); + delta += static_cast<int>(code->instruction_end() - prev_pc); + EnterComment(isolate, "NoComment", delta); + } + } +} + + +void OldSpace::ReportStatistics() { + int pct = static_cast<int>(Available() * 100 / Capacity()); + PrintF(" capacity: %" V8_PTR_PREFIX "d" + ", waste: %" V8_PTR_PREFIX "d" + ", available: %" V8_PTR_PREFIX "d, %%%d\n", + Capacity(), Waste(), Available(), pct); + + ClearHistograms(); + HeapObjectIterator obj_it(this); + for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) + CollectHistogramInfo(obj); + ReportHistogram(true); +} +#endif + +// ----------------------------------------------------------------------------- +// FixedSpace implementation + +void FixedSpace::PrepareForMarkCompact(bool will_compact) { + // Call prepare of the super class. + PagedSpace::PrepareForMarkCompact(will_compact); + + if (will_compact) { + // Reset relocation info. + MCResetRelocationInfo(); + + // During a compacting collection, everything in the space is considered + // 'available' (set by the call to MCResetRelocationInfo) and we will + // rediscover live and wasted bytes during the collection. + ASSERT(Available() == Capacity()); + } else { + // During a non-compacting collection, everything below the linear + // allocation pointer except wasted top-of-page blocks is considered + // allocated and we will rediscover available bytes during the + // collection. + accounting_stats_.AllocateBytes(free_list_.available()); + } + + // Clear the free list before a full GC---it will be rebuilt afterward. + free_list_.Reset(); +} + + +void FixedSpace::MCCommitRelocationInfo() { + // Update fast allocation info. + allocation_info_.top = mc_forwarding_info_.top; + allocation_info_.limit = mc_forwarding_info_.limit; + ASSERT(allocation_info_.VerifyPagedAllocation()); + + // The space is compacted and we haven't yet wasted any space. + ASSERT(Waste() == 0); + + // Update allocation_top of each page in use and compute waste. + int computed_size = 0; + PageIterator it(this, PageIterator::PAGES_USED_BY_MC); + while (it.has_next()) { + Page* page = it.next(); + Address page_top = page->AllocationTop(); + computed_size += static_cast<int>(page_top - page->ObjectAreaStart()); + if (it.has_next()) { + accounting_stats_.WasteBytes( + static_cast<int>(page->ObjectAreaEnd() - page_top)); + page->SetAllocationWatermark(page_top); + } + } + + // Make sure the computed size - based on the used portion of the + // pages in use - matches the size we adjust during allocation. + ASSERT(computed_size == Size()); +} + + +// Slow case for normal allocation. Try in order: (1) allocate in the next +// page in the space, (2) allocate off the space's free list, (3) expand the +// space, (4) fail. +HeapObject* FixedSpace::SlowAllocateRaw(int size_in_bytes) { + ASSERT_EQ(object_size_in_bytes_, size_in_bytes); + // Linear allocation in this space has failed. If there is another page + // in the space, move to that page and allocate there. This allocation + // should succeed. + Page* current_page = TopPageOf(allocation_info_); + if (current_page->next_page()->is_valid()) { + return AllocateInNextPage(current_page, size_in_bytes); + } + + // There is no next page in this space. Try free list allocation unless + // that is currently forbidden. The fixed space free list implicitly assumes + // that all free blocks are of the fixed size. + if (!heap()->linear_allocation()) { + Object* result; + MaybeObject* maybe = free_list_.Allocate(); + if (maybe->ToObject(&result)) { + accounting_stats_.AllocateBytes(size_in_bytes); + HeapObject* obj = HeapObject::cast(result); + Page* p = Page::FromAddress(obj->address()); + + if (obj->address() >= p->AllocationWatermark()) { + // There should be no hole between the allocation watermark + // and allocated object address. + // Memory above the allocation watermark was not swept and + // might contain garbage pointers to new space. + ASSERT(obj->address() == p->AllocationWatermark()); + p->SetAllocationWatermark(obj->address() + size_in_bytes); + } + + return obj; + } + } + + // Free list allocation failed and there is no next page. Fail if we have + // hit the old generation size limit that should cause a garbage + // collection. + if (!heap()->always_allocate() && + heap()->OldGenerationAllocationLimitReached()) { + return NULL; + } + + // Try to expand the space and allocate in the new next page. + ASSERT(!current_page->next_page()->is_valid()); + if (Expand(current_page)) { + return AllocateInNextPage(current_page, size_in_bytes); + } + + // Finally, fail. + return NULL; +} + + +// Move to the next page (there is assumed to be one) and allocate there. +// The top of page block is always wasted, because it is too small to hold a +// map. +HeapObject* FixedSpace::AllocateInNextPage(Page* current_page, + int size_in_bytes) { + ASSERT(current_page->next_page()->is_valid()); + ASSERT(allocation_info_.top == PageAllocationLimit(current_page)); + ASSERT_EQ(object_size_in_bytes_, size_in_bytes); + Page* next_page = current_page->next_page(); + next_page->ClearGCFields(); + current_page->SetAllocationWatermark(allocation_info_.top); + accounting_stats_.WasteBytes(page_extra_); + SetAllocationInfo(&allocation_info_, next_page); + return AllocateLinearly(&allocation_info_, size_in_bytes); +} + + +void FixedSpace::DeallocateBlock(Address start, + int size_in_bytes, + bool add_to_freelist) { + // Free-list elements in fixed space are assumed to have a fixed size. + // We break the free block into chunks and add them to the free list + // individually. + int size = object_size_in_bytes(); + ASSERT(size_in_bytes % size == 0); + Address end = start + size_in_bytes; + for (Address a = start; a < end; a += size) { + Free(a, add_to_freelist); + } +} + + +#ifdef DEBUG +void FixedSpace::ReportStatistics() { + int pct = static_cast<int>(Available() * 100 / Capacity()); + PrintF(" capacity: %" V8_PTR_PREFIX "d" + ", waste: %" V8_PTR_PREFIX "d" + ", available: %" V8_PTR_PREFIX "d, %%%d\n", + Capacity(), Waste(), Available(), pct); + + ClearHistograms(); + HeapObjectIterator obj_it(this); + for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) + CollectHistogramInfo(obj); + ReportHistogram(false); +} +#endif + + +// ----------------------------------------------------------------------------- +// MapSpace implementation + +void MapSpace::PrepareForMarkCompact(bool will_compact) { + // Call prepare of the super class. + FixedSpace::PrepareForMarkCompact(will_compact); + + if (will_compact) { + // Initialize map index entry. + int page_count = 0; + PageIterator it(this, PageIterator::ALL_PAGES); + while (it.has_next()) { + ASSERT_MAP_PAGE_INDEX(page_count); + + Page* p = it.next(); + ASSERT(p->mc_page_index == page_count); + + page_addresses_[page_count++] = p->address(); + } + } +} + + +#ifdef DEBUG +void MapSpace::VerifyObject(HeapObject* object) { + // The object should be a map or a free-list node. + ASSERT(object->IsMap() || object->IsByteArray()); +} +#endif + + +// ----------------------------------------------------------------------------- +// GlobalPropertyCellSpace implementation + +#ifdef DEBUG +void CellSpace::VerifyObject(HeapObject* object) { + // The object should be a global object property cell or a free-list node. + ASSERT(object->IsJSGlobalPropertyCell() || + object->map() == heap()->two_pointer_filler_map()); +} +#endif + + +// ----------------------------------------------------------------------------- +// LargeObjectIterator + +LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space) { + current_ = space->first_chunk_; + size_func_ = NULL; +} + + +LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space, + HeapObjectCallback size_func) { + current_ = space->first_chunk_; + size_func_ = size_func; +} + + +HeapObject* LargeObjectIterator::next() { + if (current_ == NULL) return NULL; + + HeapObject* object = current_->GetObject(); + current_ = current_->next(); + return object; +} + + +// ----------------------------------------------------------------------------- +// LargeObjectChunk + +LargeObjectChunk* LargeObjectChunk::New(int size_in_bytes, + Executability executable) { + size_t requested = ChunkSizeFor(size_in_bytes); + size_t size; + Isolate* isolate = Isolate::Current(); + void* mem = isolate->memory_allocator()->AllocateRawMemory( + requested, &size, executable); + if (mem == NULL) return NULL; + + // The start of the chunk may be overlayed with a page so we have to + // make sure that the page flags fit in the size field. + ASSERT((size & Page::kPageFlagMask) == 0); + + LOG(isolate, NewEvent("LargeObjectChunk", mem, size)); + if (size < requested) { + isolate->memory_allocator()->FreeRawMemory( + mem, size, executable); + LOG(isolate, DeleteEvent("LargeObjectChunk", mem)); + return NULL; + } + + ObjectSpace space = (executable == EXECUTABLE) + ? kObjectSpaceCodeSpace + : kObjectSpaceLoSpace; + isolate->memory_allocator()->PerformAllocationCallback( + space, kAllocationActionAllocate, size); + + LargeObjectChunk* chunk = reinterpret_cast<LargeObjectChunk*>(mem); + chunk->size_ = size; + Page* page = Page::FromAddress(RoundUp(chunk->address(), Page::kPageSize)); + page->heap_ = isolate->heap(); + return chunk; +} + + +int LargeObjectChunk::ChunkSizeFor(int size_in_bytes) { + int os_alignment = static_cast<int>(OS::AllocateAlignment()); + if (os_alignment < Page::kPageSize) { + size_in_bytes += (Page::kPageSize - os_alignment); + } + return size_in_bytes + Page::kObjectStartOffset; +} + +// ----------------------------------------------------------------------------- +// LargeObjectSpace + +LargeObjectSpace::LargeObjectSpace(Heap* heap, AllocationSpace id) + : Space(heap, id, NOT_EXECUTABLE), // Managed on a per-allocation basis + first_chunk_(NULL), + size_(0), + page_count_(0), + objects_size_(0) {} + + +bool LargeObjectSpace::Setup() { + first_chunk_ = NULL; + size_ = 0; + page_count_ = 0; + objects_size_ = 0; + return true; +} + + +void LargeObjectSpace::TearDown() { + while (first_chunk_ != NULL) { + LargeObjectChunk* chunk = first_chunk_; + first_chunk_ = first_chunk_->next(); + LOG(heap()->isolate(), DeleteEvent("LargeObjectChunk", chunk->address())); + Page* page = Page::FromAddress(RoundUp(chunk->address(), Page::kPageSize)); + Executability executable = + page->IsPageExecutable() ? EXECUTABLE : NOT_EXECUTABLE; + ObjectSpace space = kObjectSpaceLoSpace; + if (executable == EXECUTABLE) space = kObjectSpaceCodeSpace; + size_t size = chunk->size(); + heap()->isolate()->memory_allocator()->FreeRawMemory(chunk->address(), + size, + executable); + heap()->isolate()->memory_allocator()->PerformAllocationCallback( + space, kAllocationActionFree, size); + } + + size_ = 0; + page_count_ = 0; + objects_size_ = 0; +} + + +#ifdef ENABLE_HEAP_PROTECTION + +void LargeObjectSpace::Protect() { + LargeObjectChunk* chunk = first_chunk_; + while (chunk != NULL) { + heap()->isolate()->memory_allocator()->Protect(chunk->address(), + chunk->size()); + chunk = chunk->next(); + } +} + + +void LargeObjectSpace::Unprotect() { + LargeObjectChunk* chunk = first_chunk_; + while (chunk != NULL) { + bool is_code = chunk->GetObject()->IsCode(); + heap()->isolate()->memory_allocator()->Unprotect(chunk->address(), + chunk->size(), is_code ? EXECUTABLE : NOT_EXECUTABLE); + chunk = chunk->next(); + } +} + +#endif + + +MaybeObject* 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(identity()); + } + + LargeObjectChunk* chunk = LargeObjectChunk::New(requested_size, executable); + if (chunk == NULL) { + return Failure::RetryAfterGC(identity()); + } + + size_ += static_cast<int>(chunk->size()); + objects_size_ += requested_size; + page_count_++; + chunk->set_next(first_chunk_); + first_chunk_ = chunk; + + // Initialize page header. + Page* page = Page::FromAddress(RoundUp(chunk->address(), Page::kPageSize)); + Address object_address = page->ObjectAreaStart(); + + // Clear the low order bit of the second word in the page to flag it as a + // large object page. If the chunk_size happened to be written there, its + // low order bit should already be clear. + page->SetIsLargeObjectPage(true); + page->SetIsPageExecutable(executable); + page->SetRegionMarks(Page::kAllRegionsCleanMarks); + return HeapObject::FromAddress(object_address); +} + + +MaybeObject* LargeObjectSpace::AllocateRawCode(int size_in_bytes) { + ASSERT(0 < size_in_bytes); + return AllocateRawInternal(size_in_bytes, + size_in_bytes, + EXECUTABLE); +} + + +MaybeObject* LargeObjectSpace::AllocateRawFixedArray(int size_in_bytes) { + ASSERT(0 < size_in_bytes); + return AllocateRawInternal(size_in_bytes, + size_in_bytes, + NOT_EXECUTABLE); +} + + +MaybeObject* LargeObjectSpace::AllocateRaw(int size_in_bytes) { + ASSERT(0 < size_in_bytes); + return AllocateRawInternal(size_in_bytes, + size_in_bytes, + NOT_EXECUTABLE); +} + + +// GC support +MaybeObject* 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(); +} + + +LargeObjectChunk* LargeObjectSpace::FindChunkContainingPc(Address pc) { + // TODO(853): Change this implementation to only find executable + // chunks and use some kind of hash-based approach to speed it up. + for (LargeObjectChunk* chunk = first_chunk_; + chunk != NULL; + chunk = chunk->next()) { + Address chunk_address = chunk->address(); + if (chunk_address <= pc && pc < chunk_address + chunk->size()) { + return chunk; + } + } + return NULL; +} + + +void LargeObjectSpace::IterateDirtyRegions(ObjectSlotCallback copy_object) { + LargeObjectIterator it(this); + for (HeapObject* object = it.next(); object != NULL; object = it.next()) { + // We only have code, sequential strings, or fixed arrays in large + // object space, and only fixed arrays can possibly contain pointers to + // the young generation. + if (object->IsFixedArray()) { + Page* page = Page::FromAddress(object->address()); + uint32_t marks = page->GetRegionMarks(); + uint32_t newmarks = Page::kAllRegionsCleanMarks; + + if (marks != Page::kAllRegionsCleanMarks) { + // For a large page a single dirty mark corresponds to several + // regions (modulo 32). So we treat a large page as a sequence of + // normal pages of size Page::kPageSize having same dirty marks + // and subsequently iterate dirty regions on each of these pages. + Address start = object->address(); + Address end = page->ObjectAreaEnd(); + Address object_end = start + object->Size(); + + // Iterate regions of the first normal page covering object. + uint32_t first_region_number = page->GetRegionNumberForAddress(start); + newmarks |= + heap()->IterateDirtyRegions(marks >> first_region_number, + start, + end, + &Heap::IteratePointersInDirtyRegion, + copy_object) << first_region_number; + + start = end; + end = start + Page::kPageSize; + while (end <= object_end) { + // Iterate next 32 regions. + newmarks |= + heap()->IterateDirtyRegions(marks, + start, + end, + &Heap::IteratePointersInDirtyRegion, + copy_object); + start = end; + end = start + Page::kPageSize; + } + + if (start != object_end) { + // Iterate the last piece of an object which is less than + // Page::kPageSize. + newmarks |= + heap()->IterateDirtyRegions(marks, + start, + object_end, + &Heap::IteratePointersInDirtyRegion, + copy_object); + } + + page->SetRegionMarks(newmarks); + } + } + } +} + + +void LargeObjectSpace::FreeUnmarkedObjects() { + LargeObjectChunk* previous = NULL; + LargeObjectChunk* current = first_chunk_; + while (current != NULL) { + HeapObject* object = current->GetObject(); + if (object->IsMarked()) { + object->ClearMark(); + heap()->mark_compact_collector()->tracer()->decrement_marked_count(); + previous = current; + current = current->next(); + } else { + Page* page = Page::FromAddress(RoundUp(current->address(), + Page::kPageSize)); + Executability executable = + page->IsPageExecutable() ? EXECUTABLE : NOT_EXECUTABLE; + 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. + heap()->mark_compact_collector()->ReportDeleteIfNeeded( + object, heap()->isolate()); + LiveObjectList::ProcessNonLive(object); + + size_ -= static_cast<int>(chunk_size); + objects_size_ -= object->Size(); + page_count_--; + ObjectSpace space = kObjectSpaceLoSpace; + if (executable == EXECUTABLE) space = kObjectSpaceCodeSpace; + heap()->isolate()->memory_allocator()->FreeRawMemory(chunk_address, + chunk_size, + executable); + heap()->isolate()->memory_allocator()->PerformAllocationCallback( + space, kAllocationActionFree, size_); + LOG(heap()->isolate(), DeleteEvent("LargeObjectChunk", chunk_address)); + } + } +} + + +bool LargeObjectSpace::Contains(HeapObject* object) { + Address address = object->address(); + if (heap()->new_space()->Contains(address)) { + return false; + } + Page* page = Page::FromAddress(address); + + SLOW_ASSERT(!page->IsLargeObjectPage() + || !FindObject(address)->IsFailure()); + + return page->IsLargeObjectPage(); +} + + +#ifdef DEBUG +// We do not assume that the large object iterator works, because it depends +// on the invariants we are checking during verification. +void LargeObjectSpace::Verify() { + for (LargeObjectChunk* chunk = first_chunk_; + chunk != NULL; + chunk = chunk->next()) { + // Each chunk contains an object that starts at the large object page's + // object area start. + HeapObject* object = chunk->GetObject(); + Page* page = Page::FromAddress(object->address()); + ASSERT(object->address() == page->ObjectAreaStart()); + + // The first word should be a map, and we expect all map pointers to be + // in map space. + Map* map = object->map(); + ASSERT(map->IsMap()); + ASSERT(heap()->map_space()->Contains(map)); + + // We have only code, sequential strings, external strings + // (sequential strings that have been morphed into external + // strings), fixed arrays, and byte arrays in large object space. + ASSERT(object->IsCode() || object->IsSeqString() || + object->IsExternalString() || object->IsFixedArray() || + object->IsByteArray()); + + // The object itself should look OK. + object->Verify(); + + // Byte arrays and strings don't have interior pointers. + if (object->IsCode()) { + VerifyPointersVisitor code_visitor; + object->IterateBody(map->instance_type(), + object->Size(), + &code_visitor); + } else if (object->IsFixedArray()) { + // We loop over fixed arrays ourselves, rather then using the visitor, + // because the visitor doesn't support the start/offset iteration + // needed for IsRegionDirty. + FixedArray* array = FixedArray::cast(object); + for (int j = 0; j < array->length(); j++) { + Object* element = array->get(j); + if (element->IsHeapObject()) { + HeapObject* element_object = HeapObject::cast(element); + ASSERT(heap()->Contains(element_object)); + ASSERT(element_object->map()->IsMap()); + if (heap()->InNewSpace(element_object)) { + Address array_addr = object->address(); + Address element_addr = array_addr + FixedArray::kHeaderSize + + j * kPointerSize; + + ASSERT(Page::FromAddress(array_addr)->IsRegionDirty(element_addr)); + } + } + } + } + } +} + + +void LargeObjectSpace::Print() { + LargeObjectIterator it(this); + for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) { + obj->Print(); + } +} + + +void LargeObjectSpace::ReportStatistics() { + PrintF(" size: %" V8_PTR_PREFIX "d\n", size_); + int num_objects = 0; + ClearHistograms(); + LargeObjectIterator it(this); + for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) { + num_objects++; + CollectHistogramInfo(obj); + } + + PrintF(" number of objects %d, " + "size of objects %" V8_PTR_PREFIX "d\n", num_objects, objects_size_); + if (num_objects > 0) ReportHistogram(false); +} + + +void LargeObjectSpace::CollectCodeStatistics() { + Isolate* isolate = heap()->isolate(); + LargeObjectIterator obj_it(this); + for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next()) { + if (obj->IsCode()) { + Code* code = Code::cast(obj); + isolate->code_kind_statistics()[code->kind()] += code->Size(); + } + } +} +#endif // DEBUG + +} } // namespace v8::internal |