1// Copyright 2016 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef V8_ZONE_ACCOUNTING_ALLOCATOR_H_
6#define V8_ZONE_ACCOUNTING_ALLOCATOR_H_
7
8#include "include/v8-platform.h"
9#include "src/base/atomic-utils.h"
10#include "src/base/atomicops.h"
11#include "src/base/macros.h"
12#include "src/base/platform/mutex.h"
13#include "src/base/platform/semaphore.h"
14#include "src/base/platform/time.h"
15#include "src/zone/zone-segment.h"
16#include "testing/gtest/include/gtest/gtest_prod.h"
17
18namespace v8 {
19namespace internal {
20
21class V8_EXPORT_PRIVATE AccountingAllocator {
22 public:
23  static const size_t kMaxPoolSizeLowMemoryDevice = 8ul * KB;
24  static const size_t kMaxPoolSizeMediumMemoryDevice = 8ul * KB;
25  static const size_t kMaxPoolSizeHighMemoryDevice = 8ul * KB;
26  static const size_t kMaxPoolSizeHugeMemoryDevice = 8ul * KB;
27
28  AccountingAllocator();
29  virtual ~AccountingAllocator();
30
31  // Gets an empty segment from the pool or creates a new one.
32  virtual Segment* GetSegment(size_t bytes);
33  // Return unneeded segments to either insert them into the pool or release
34  // them if the pool is already full or memory pressure is high.
35  virtual void ReturnSegment(Segment* memory);
36
37  size_t GetCurrentMemoryUsage() const;
38  size_t GetMaxMemoryUsage() const;
39
40  size_t GetCurrentPoolSize() const;
41
42  void MemoryPressureNotification(MemoryPressureLevel level);
43  // Configures the zone segment pool size limits so the pool does not
44  // grow bigger than max_pool_size.
45  // TODO(heimbuef): Do not accept segments to pool that are larger than
46  // their size class requires. Sometimes the zones generate weird segments.
47  void ConfigureSegmentPool(const size_t max_pool_size);
48
49  virtual void ZoneCreation(const Zone* zone) {}
50  virtual void ZoneDestruction(const Zone* zone) {}
51
52 private:
53  FRIEND_TEST(Zone, SegmentPoolConstraints);
54
55  static const size_t kMinSegmentSizePower = 13;
56  static const size_t kMaxSegmentSizePower = 18;
57
58  STATIC_ASSERT(kMinSegmentSizePower <= kMaxSegmentSizePower);
59
60  static const size_t kNumberBuckets =
61      1 + kMaxSegmentSizePower - kMinSegmentSizePower;
62
63  // Allocates a new segment. Returns nullptr on failed allocation.
64  Segment* AllocateSegment(size_t bytes);
65  void FreeSegment(Segment* memory);
66
67  // Returns a segment from the pool of at least the requested size.
68  Segment* GetSegmentFromPool(size_t requested_size);
69  // Trys to add a segment to the pool. Returns false if the pool is full.
70  bool AddSegmentToPool(Segment* segment);
71
72  // Empties the pool and puts all its contents onto the garbage stack.
73  void ClearPool();
74
75  Segment* unused_segments_heads_[kNumberBuckets];
76
77  size_t unused_segments_sizes_[kNumberBuckets];
78  size_t unused_segments_max_sizes_[kNumberBuckets];
79
80  base::Mutex unused_segments_mutex_;
81
82  base::AtomicWord current_memory_usage_ = 0;
83  base::AtomicWord max_memory_usage_ = 0;
84  base::AtomicWord current_pool_size_ = 0;
85
86  base::AtomicValue<MemoryPressureLevel> memory_pressure_level_;
87
88  DISALLOW_COPY_AND_ASSIGN(AccountingAllocator);
89};
90
91}  // namespace internal
92}  // namespace v8
93
94#endif  // V8_ZONE_ACCOUNTING_ALLOCATOR_H_
95