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// Copyright 2011 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.
#ifndef V8_SPACES_INL_H_
#define V8_SPACES_INL_H_
#include "isolate.h"
#include "spaces.h"
#include "v8memory.h"
namespace v8 {
namespace internal {
// -----------------------------------------------------------------------------
// Bitmap
void Bitmap::Clear(MemoryChunk* chunk) {
Bitmap* bitmap = chunk->markbits();
for (int i = 0; i < bitmap->CellsCount(); i++) bitmap->cells()[i] = 0;
chunk->ResetLiveBytes();
}
// -----------------------------------------------------------------------------
// PageIterator
PageIterator::PageIterator(PagedSpace* space)
: space_(space),
prev_page_(&space->anchor_),
next_page_(prev_page_->next_page()) { }
bool PageIterator::has_next() {
return next_page_ != &space_->anchor_;
}
Page* PageIterator::next() {
ASSERT(has_next());
prev_page_ = next_page_;
next_page_ = next_page_->next_page();
return prev_page_;
}
// -----------------------------------------------------------------------------
// NewSpacePageIterator
NewSpacePageIterator::NewSpacePageIterator(NewSpace* space)
: prev_page_(NewSpacePage::FromAddress(space->ToSpaceStart())->prev_page()),
next_page_(NewSpacePage::FromAddress(space->ToSpaceStart())),
last_page_(NewSpacePage::FromLimit(space->ToSpaceEnd())) { }
NewSpacePageIterator::NewSpacePageIterator(SemiSpace* space)
: prev_page_(space->anchor()),
next_page_(prev_page_->next_page()),
last_page_(prev_page_->prev_page()) { }
NewSpacePageIterator::NewSpacePageIterator(Address start, Address limit)
: prev_page_(NewSpacePage::FromAddress(start)->prev_page()),
next_page_(NewSpacePage::FromAddress(start)),
last_page_(NewSpacePage::FromLimit(limit)) {
SemiSpace::AssertValidRange(start, limit);
}
bool NewSpacePageIterator::has_next() {
return prev_page_ != last_page_;
}
NewSpacePage* NewSpacePageIterator::next() {
ASSERT(has_next());
prev_page_ = next_page_;
next_page_ = next_page_->next_page();
return prev_page_;
}
// -----------------------------------------------------------------------------
// HeapObjectIterator
HeapObject* HeapObjectIterator::FromCurrentPage() {
while (cur_addr_ != cur_end_) {
if (cur_addr_ == space_->top() && cur_addr_ != space_->limit()) {
cur_addr_ = space_->limit();
continue;
}
HeapObject* obj = HeapObject::FromAddress(cur_addr_);
int obj_size = (size_func_ == NULL) ? obj->Size() : size_func_(obj);
cur_addr_ += obj_size;
ASSERT(cur_addr_ <= cur_end_);
if (!obj->IsFiller()) {
ASSERT_OBJECT_SIZE(obj_size);
return obj;
}
}
return NULL;
}
// -----------------------------------------------------------------------------
// MemoryAllocator
#ifdef ENABLE_HEAP_PROTECTION
void MemoryAllocator::Protect(Address start, size_t size) {
OS::Protect(start, size);
}
void MemoryAllocator::Unprotect(Address start,
size_t size,
Executability executable) {
OS::Unprotect(start, size, executable);
}
void MemoryAllocator::ProtectChunkFromPage(Page* page) {
int id = GetChunkId(page);
OS::Protect(chunks_[id].address(), chunks_[id].size());
}
void MemoryAllocator::UnprotectChunkFromPage(Page* page) {
int id = GetChunkId(page);
OS::Unprotect(chunks_[id].address(), chunks_[id].size(),
chunks_[id].owner()->executable() == EXECUTABLE);
}
#endif
// --------------------------------------------------------------------------
// PagedSpace
Page* Page::Initialize(Heap* heap,
MemoryChunk* chunk,
Executability executable,
PagedSpace* owner) {
Page* page = reinterpret_cast<Page*>(chunk);
ASSERT(chunk->size() <= static_cast<size_t>(kPageSize));
ASSERT(chunk->owner() == owner);
owner->IncreaseCapacity(page->area_size());
owner->Free(page->area_start(), page->area_size());
heap->incremental_marking()->SetOldSpacePageFlags(chunk);
return page;
}
bool PagedSpace::Contains(Address addr) {
Page* p = Page::FromAddress(addr);
if (!p->is_valid()) return false;
return p->owner() == this;
}
void MemoryChunk::set_scan_on_scavenge(bool scan) {
if (scan) {
if (!scan_on_scavenge()) heap_->increment_scan_on_scavenge_pages();
SetFlag(SCAN_ON_SCAVENGE);
} else {
if (scan_on_scavenge()) heap_->decrement_scan_on_scavenge_pages();
ClearFlag(SCAN_ON_SCAVENGE);
}
heap_->incremental_marking()->SetOldSpacePageFlags(this);
}
MemoryChunk* MemoryChunk::FromAnyPointerAddress(Address addr) {
MemoryChunk* maybe = reinterpret_cast<MemoryChunk*>(
OffsetFrom(addr) & ~Page::kPageAlignmentMask);
if (maybe->owner() != NULL) return maybe;
LargeObjectIterator iterator(HEAP->lo_space());
for (HeapObject* o = iterator.Next(); o != NULL; o = iterator.Next()) {
// Fixed arrays are the only pointer-containing objects in large object
// space.
if (o->IsFixedArray()) {
MemoryChunk* chunk = MemoryChunk::FromAddress(o->address());
if (chunk->Contains(addr)) {
return chunk;
}
}
}
UNREACHABLE();
return NULL;
}
PointerChunkIterator::PointerChunkIterator(Heap* heap)
: state_(kOldPointerState),
old_pointer_iterator_(heap->old_pointer_space()),
map_iterator_(heap->map_space()),
lo_iterator_(heap->lo_space()) { }
Page* Page::next_page() {
ASSERT(next_chunk()->owner() == owner());
return static_cast<Page*>(next_chunk());
}
Page* Page::prev_page() {
ASSERT(prev_chunk()->owner() == owner());
return static_cast<Page*>(prev_chunk());
}
void Page::set_next_page(Page* page) {
ASSERT(page->owner() == owner());
set_next_chunk(page);
}
void Page::set_prev_page(Page* page) {
ASSERT(page->owner() == owner());
set_prev_chunk(page);
}
// Try linear allocation in the page of alloc_info's allocation top. Does
// not contain slow case logic (e.g. move to the next page or try free list
// allocation) so it can be used by all the allocation functions and for all
// the paged spaces.
HeapObject* PagedSpace::AllocateLinearly(int size_in_bytes) {
Address current_top = allocation_info_.top;
Address new_top = current_top + size_in_bytes;
if (new_top > allocation_info_.limit) return NULL;
allocation_info_.top = new_top;
return HeapObject::FromAddress(current_top);
}
// Raw allocation.
MaybeObject* PagedSpace::AllocateRaw(int size_in_bytes) {
HeapObject* object = AllocateLinearly(size_in_bytes);
if (object != NULL) {
if (identity() == CODE_SPACE) {
SkipList::Update(object->address(), size_in_bytes);
}
return object;
}
object = free_list_.Allocate(size_in_bytes);
if (object != NULL) {
if (identity() == CODE_SPACE) {
SkipList::Update(object->address(), size_in_bytes);
}
return object;
}
object = SlowAllocateRaw(size_in_bytes);
if (object != NULL) {
if (identity() == CODE_SPACE) {
SkipList::Update(object->address(), size_in_bytes);
}
return object;
}
return Failure::RetryAfterGC(identity());
}
// -----------------------------------------------------------------------------
// NewSpace
MaybeObject* NewSpace::AllocateRaw(int size_in_bytes) {
Address old_top = allocation_info_.top;
#ifdef DEBUG
// If we are stressing compaction we waste some memory in new space
// in order to get more frequent GCs.
if (FLAG_stress_compaction && !HEAP->linear_allocation()) {
if (allocation_info_.limit - old_top >= size_in_bytes * 4) {
int filler_size = size_in_bytes * 4;
for (int i = 0; i < filler_size; i += kPointerSize) {
*(reinterpret_cast<Object**>(old_top + i)) =
HEAP->one_pointer_filler_map();
}
old_top += filler_size;
allocation_info_.top += filler_size;
}
}
#endif
if (allocation_info_.limit - old_top < size_in_bytes) {
return SlowAllocateRaw(size_in_bytes);
}
Object* obj = HeapObject::FromAddress(old_top);
allocation_info_.top += size_in_bytes;
ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
return obj;
}
LargePage* LargePage::Initialize(Heap* heap, MemoryChunk* chunk) {
heap->incremental_marking()->SetOldSpacePageFlags(chunk);
return static_cast<LargePage*>(chunk);
}
intptr_t LargeObjectSpace::Available() {
return ObjectSizeFor(heap()->isolate()->memory_allocator()->Available());
}
template <typename StringType>
void NewSpace::ShrinkStringAtAllocationBoundary(String* string, int length) {
ASSERT(length <= string->length());
ASSERT(string->IsSeqString());
ASSERT(string->address() + StringType::SizeFor(string->length()) ==
allocation_info_.top);
Address old_top = allocation_info_.top;
allocation_info_.top =
string->address() + StringType::SizeFor(length);
string->set_length(length);
if (Marking::IsBlack(Marking::MarkBitFrom(string))) {
int delta = static_cast<int>(old_top - allocation_info_.top);
MemoryChunk::IncrementLiveBytesFromMutator(string->address(), -delta);
}
}
bool FreeListNode::IsFreeListNode(HeapObject* object) {
Map* map = object->map();
Heap* heap = object->GetHeap();
return map == heap->raw_unchecked_free_space_map()
|| map == heap->raw_unchecked_one_pointer_filler_map()
|| map == heap->raw_unchecked_two_pointer_filler_map();
}
} } // namespace v8::internal
#endif // V8_SPACES_INL_H_