Line data Source code
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_HEAP_EMBEDDER_TRACING_H_
6 : #define V8_HEAP_EMBEDDER_TRACING_H_
7 :
8 : #include "include/v8.h"
9 : #include "src/flags.h"
10 : #include "src/globals.h"
11 :
12 : namespace v8 {
13 : namespace internal {
14 :
15 : class Heap;
16 : class JSObject;
17 :
18 : class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
19 : public:
20 : typedef std::pair<void*, void*> WrapperInfo;
21 : typedef std::vector<WrapperInfo> WrapperCache;
22 :
23 : class V8_EXPORT_PRIVATE ProcessingScope {
24 : public:
25 : explicit ProcessingScope(LocalEmbedderHeapTracer* tracer);
26 : ~ProcessingScope();
27 :
28 : void TracePossibleWrapper(JSObject js_object);
29 :
30 : void AddWrapperInfoForTesting(WrapperInfo info);
31 :
32 : private:
33 : static constexpr size_t kWrapperCacheSize = 1000;
34 :
35 : void FlushWrapperCacheIfFull();
36 :
37 : LocalEmbedderHeapTracer* const tracer_;
38 : WrapperCache wrapper_cache_;
39 : };
40 :
41 62898 : explicit LocalEmbedderHeapTracer(Isolate* isolate) : isolate_(isolate) {}
42 :
43 : ~LocalEmbedderHeapTracer() {
44 62882 : if (remote_tracer_) remote_tracer_->isolate_ = nullptr;
45 : }
46 :
47 726431 : bool InUse() const { return remote_tracer_ != nullptr; }
48 : EmbedderHeapTracer* remote_tracer() const { return remote_tracer_; }
49 :
50 : void SetRemoteTracer(EmbedderHeapTracer* tracer);
51 : void TracePrologue();
52 : void TraceEpilogue();
53 : void EnterFinalPause();
54 : bool Trace(double deadline);
55 : bool IsRemoteTracingDone();
56 :
57 0 : void NotifyV8MarkingWorklistWasEmpty() {
58 0 : num_v8_marking_worklist_was_empty_++;
59 0 : }
60 :
61 2540958 : bool ShouldFinalizeIncrementalMarking() {
62 : static const size_t kMaxIncrementalFixpointRounds = 3;
63 2540958 : return !FLAG_incremental_marking_wrappers || !InUse() ||
64 1270479 : (IsRemoteTracingDone() && embedder_worklist_empty_) ||
65 1270479 : num_v8_marking_worklist_was_empty_ > kMaxIncrementalFixpointRounds;
66 : }
67 :
68 : void SetEmbedderStackStateForNextFinalization(
69 : EmbedderHeapTracer::EmbedderStackState stack_state);
70 :
71 : void SetEmbedderWorklistEmpty(bool is_empty) {
72 0 : embedder_worklist_empty_ = is_empty;
73 : }
74 :
75 : private:
76 : Isolate* const isolate_;
77 : EmbedderHeapTracer* remote_tracer_ = nullptr;
78 :
79 : size_t num_v8_marking_worklist_was_empty_ = 0;
80 : EmbedderHeapTracer::EmbedderStackState embedder_stack_state_ =
81 : EmbedderHeapTracer::kUnknown;
82 : // Indicates whether the embedder worklist was observed empty on the main
83 : // thread. This is opportunistic as concurrent marking tasks may hold local
84 : // segments of potential embedder fields to move to the main thread.
85 : bool embedder_worklist_empty_ = false;
86 :
87 : friend class EmbedderStackStateScope;
88 : };
89 :
90 : class V8_EXPORT_PRIVATE EmbedderStackStateScope final {
91 : public:
92 : EmbedderStackStateScope(LocalEmbedderHeapTracer* local_tracer,
93 : EmbedderHeapTracer::EmbedderStackState stack_state)
94 : : local_tracer_(local_tracer),
95 144726 : old_stack_state_(local_tracer_->embedder_stack_state_) {
96 144726 : local_tracer_->embedder_stack_state_ = stack_state;
97 : }
98 :
99 : ~EmbedderStackStateScope() {
100 144727 : local_tracer_->embedder_stack_state_ = old_stack_state_;
101 : }
102 :
103 : private:
104 : LocalEmbedderHeapTracer* const local_tracer_;
105 : const EmbedderHeapTracer::EmbedderStackState old_stack_state_;
106 : };
107 :
108 : } // namespace internal
109 : } // namespace v8
110 :
111 : #endif // V8_HEAP_EMBEDDER_TRACING_H_
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