File: write_barrier.h

package info (click to toggle)
chromium 138.0.7204.183-1
  • links: PTS, VCS
  • area: main
  • in suites: trixie
  • size: 6,071,908 kB
  • sloc: cpp: 34,937,088; ansic: 7,176,967; javascript: 4,110,704; python: 1,419,953; asm: 946,768; xml: 739,971; pascal: 187,324; sh: 89,623; perl: 88,663; objc: 79,944; sql: 50,304; cs: 41,786; fortran: 24,137; makefile: 21,806; php: 13,980; tcl: 13,166; yacc: 8,925; ruby: 7,485; awk: 3,720; lisp: 3,096; lex: 1,327; ada: 727; jsp: 228; sed: 36
file content (99 lines) | stat: -rw-r--r-- 3,780 bytes parent folder | download | duplicates (10)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_WRITE_BARRIER_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_WRITE_BARRIER_H_

#include <type_traits>

#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/type_traits.h"
#include "v8/include/cppgc/heap-consistency.h"
#include "v8/include/cppgc/member.h"

namespace blink {

class WriteBarrier final {
  STATIC_ONLY(WriteBarrier);

  using HeapConsistency = cppgc::subtle::HeapConsistency;

 public:
  template <typename T>
  ALWAYS_INLINE static void DispatchForObject(T* element) {
    static_assert(!WTF::IsMemberOrWeakMemberType<std::decay_t<T>>::value,
                  "Member and WeakMember should use the other overload.");
    HeapConsistency::WriteBarrierParams params;
    switch (HeapConsistency::GetWriteBarrierType(element, *element, params)) {
      case HeapConsistency::WriteBarrierType::kMarking:
        HeapConsistency::DijkstraWriteBarrier(params, *element);
        break;
      case HeapConsistency::WriteBarrierType::kGenerational:
        HeapConsistency::GenerationalBarrier(params, element);
        break;
      case HeapConsistency::WriteBarrierType::kNone:
        break;
    }
  }

  // Cannot refer to blink::Member and friends here due to cyclic includes.
  template <typename T,
            typename WeaknessTag,
            typename StorageType,
            typename WriteBarrierPolicy,
            typename CheckingPolicy>
  ALWAYS_INLINE static void DispatchForObject(
      cppgc::internal::BasicMember<T,
                                   WeaknessTag,
                                   StorageType,
                                   WriteBarrierPolicy,
                                   CheckingPolicy>* element) {
    HeapConsistency::WriteBarrierParams params;
    switch (HeapConsistency::GetWriteBarrierType(*element, params)) {
      case HeapConsistency::WriteBarrierType::kMarking:
        HeapConsistency::DijkstraWriteBarrier(params, element->Get());
        break;
      case HeapConsistency::WriteBarrierType::kGenerational:
        HeapConsistency::GenerationalBarrier(params, element);
        break;
      case HeapConsistency::WriteBarrierType::kNone:
        break;
    }
  }

  // Cannot refer to blink::Member and friends here due to cyclic includes.
  template <typename T,
            typename WeaknessTag,
            typename StorageType,
            typename WriteBarrierPolicy,
            typename CheckingPolicy>
  ALWAYS_INLINE static bool IsWriteBarrierNeeded(
      cppgc::internal::BasicMember<T,
                                   WeaknessTag,
                                   StorageType,
                                   WriteBarrierPolicy,
                                   CheckingPolicy>* element) {
    HeapConsistency::WriteBarrierParams params;
    return HeapConsistency::GetWriteBarrierType(*element, params) !=
           HeapConsistency::WriteBarrierType::kNone;
  }

  static void DispatchForUncompressedSlot(void* slot, void* value) {
    HeapConsistency::WriteBarrierParams params;
    switch (HeapConsistency::GetWriteBarrierType(slot, value, params)) {
      case HeapConsistency::WriteBarrierType::kMarking:
        HeapConsistency::DijkstraWriteBarrier(params, value);
        break;
      case HeapConsistency::WriteBarrierType::kGenerational:
        HeapConsistency::GenerationalBarrierForUncompressedSlot(params, slot);
        break;
      case HeapConsistency::WriteBarrierType::kNone:
        break;
    }
  }
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_WRITE_BARRIER_H_