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// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_HEAP_LOCAL_ALLOCATOR_H_
#define V8_HEAP_LOCAL_ALLOCATOR_H_
#include "src/globals.h"
#include "src/heap/heap.h"
#include "src/heap/spaces.h"
namespace v8 {
namespace internal {
// Allocator encapsulating thread-local allocation. Assumes that all other
// allocations also go through LocalAllocator.
class LocalAllocator {
public:
static const int kLabSize = 32 * KB;
static const int kMaxLabObjectSize = 8 * KB;
explicit LocalAllocator(Heap* heap)
: heap_(heap),
new_space_(heap->new_space()),
compaction_spaces_(heap),
new_space_lab_(LocalAllocationBuffer::InvalidBuffer()),
lab_allocation_will_fail_(false) {}
// Needs to be called from the main thread to finalize this LocalAllocator.
void Finalize() {
heap_->old_space()->MergeCompactionSpace(compaction_spaces_.Get(OLD_SPACE));
heap_->code_space()->MergeCompactionSpace(
compaction_spaces_.Get(CODE_SPACE));
// Give back remaining LAB space if this LocalAllocator's new space LAB
// sits right next to new space allocation top.
const LinearAllocationArea info = new_space_lab_.Close();
const Address top = new_space_->top();
if (info.limit() != kNullAddress && info.limit() == top) {
DCHECK_NE(info.top(), kNullAddress);
*new_space_->allocation_top_address() = info.top();
}
}
inline AllocationResult Allocate(AllocationSpace space, int object_size,
AllocationAlignment alignment);
inline void FreeLast(AllocationSpace space, HeapObject* object,
int object_size);
private:
inline AllocationResult AllocateInNewSpace(int object_size,
AllocationAlignment alignment);
inline bool NewLocalAllocationBuffer();
inline AllocationResult AllocateInLAB(int object_size,
AllocationAlignment alignment);
inline void FreeLastInNewSpace(HeapObject* object, int object_size);
inline void FreeLastInOldSpace(HeapObject* object, int object_size);
Heap* const heap_;
NewSpace* const new_space_;
CompactionSpaceCollection compaction_spaces_;
LocalAllocationBuffer new_space_lab_;
bool lab_allocation_will_fail_;
};
} // namespace internal
} // namespace v8
#endif // V8_HEAP_LOCAL_ALLOCATOR_H_
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