1// Copyright 2021 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 INCLUDE_CPPGC_HEAP_STATE_H_
6#define INCLUDE_CPPGC_HEAP_STATE_H_
7
8#include "v8config.h"  // NOLINT(build/include_directory)
9
10namespace cppgc {
11
12class HeapHandle;
13
14namespace subtle {
15
16/**
17 * Helpers to peek into heap-internal state.
18 */
19class V8_EXPORT HeapState final {
20 public:
21  /**
22   * Returns whether the garbage collector is marking. This API is experimental
23   * and is expected to be removed in future.
24   *
25   * \param heap_handle The corresponding heap.
26   * \returns true if the garbage collector is currently marking, and false
27   *   otherwise.
28   */
29  static bool IsMarking(const HeapHandle& heap_handle);
30
31  /*
32   * Returns whether the garbage collector is sweeping. This API is experimental
33   * and is expected to be removed in future.
34   *
35   * \param heap_handle The corresponding heap.
36   * \returns true if the garbage collector is currently sweeping, and false
37   *   otherwise.
38   */
39  static bool IsSweeping(const HeapHandle& heap_handle);
40
41  /*
42   * Returns whether the garbage collector is currently sweeping on the thread
43   * owning this heap. This API allows the caller to determine whether it has
44   * been called from a destructor of a managed object. This API is experimental
45   * and may be removed in future.
46   *
47   * \param heap_handle The corresponding heap.
48   * \returns true if the garbage collector is currently sweeping on this
49   *   thread, and false otherwise.
50   */
51  static bool IsSweepingOnOwningThread(const HeapHandle& heap_handle);
52
53  /**
54   * Returns whether the garbage collector is in the atomic pause, i.e., the
55   * mutator is stopped from running. This API is experimental and is expected
56   * to be removed in future.
57   *
58   * \param heap_handle The corresponding heap.
59   * \returns true if the garbage collector is currently in the atomic pause,
60   *   and false otherwise.
61   */
62  static bool IsInAtomicPause(const HeapHandle& heap_handle);
63
64  /**
65   * Returns whether the last garbage collection was finalized conservatively
66   * (i.e., with a non-empty stack). This API is experimental and is expected to
67   * be removed in future.
68   *
69   * \param heap_handle The corresponding heap.
70   * \returns true if the last garbage collection was finalized conservatively,
71   * and false otherwise.
72   */
73  static bool PreviousGCWasConservative(const HeapHandle& heap_handle);
74
75 private:
76  HeapState() = delete;
77};
78
79}  // namespace subtle
80}  // namespace cppgc
81
82#endif  // INCLUDE_CPPGC_HEAP_STATE_H_
83