1 // Copyright 2017 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 #include "src/heap/stress-scavenge-observer.h"
6
7 #include "src/base/utils/random-number-generator.h"
8 #include "src/heap/heap-inl.h"
9 #include "src/heap/spaces.h"
10 #include "src/isolate.h"
11
12 namespace v8 {
13 namespace internal {
14
15 // TODO(majeski): meaningful step_size
StressScavengeObserver(Heap & heap)16 StressScavengeObserver::StressScavengeObserver(Heap& heap)
17 : AllocationObserver(64),
18 heap_(heap),
19 has_requested_gc_(false),
20 max_new_space_size_reached_(0.0) {
21 limit_percentage_ = NextLimit();
22
23 if (FLAG_trace_stress_scavenge && !FLAG_fuzzer_gc_analysis) {
24 heap_.isolate()->PrintWithTimestamp(
25 "[StressScavenge] %d%% is the new limit\n", limit_percentage_);
26 }
27 }
28
Step(int bytes_allocated,Address soon_object,size_t size)29 void StressScavengeObserver::Step(int bytes_allocated, Address soon_object,
30 size_t size) {
31 if (has_requested_gc_ || heap_.new_space()->Capacity() == 0) {
32 return;
33 }
34
35 double current_percent =
36 heap_.new_space()->Size() * 100.0 / heap_.new_space()->Capacity();
37
38 if (FLAG_trace_stress_scavenge) {
39 heap_.isolate()->PrintWithTimestamp(
40 "[Scavenge] %.2lf%% of the new space capacity reached\n",
41 current_percent);
42 }
43
44 if (FLAG_fuzzer_gc_analysis) {
45 max_new_space_size_reached_ =
46 std::max(max_new_space_size_reached_, current_percent);
47 return;
48 }
49
50 if (static_cast<int>(current_percent) >= limit_percentage_) {
51 if (FLAG_trace_stress_scavenge) {
52 heap_.isolate()->PrintWithTimestamp("[Scavenge] GC requested\n");
53 }
54
55 has_requested_gc_ = true;
56 heap_.isolate()->stack_guard()->RequestGC();
57 }
58 }
59
HasRequestedGC() const60 bool StressScavengeObserver::HasRequestedGC() const {
61 return has_requested_gc_;
62 }
63
RequestedGCDone()64 void StressScavengeObserver::RequestedGCDone() {
65 double current_percent =
66 heap_.new_space()->Size() * 100.0 / heap_.new_space()->Capacity();
67 limit_percentage_ = NextLimit(static_cast<int>(current_percent));
68
69 if (FLAG_trace_stress_scavenge) {
70 heap_.isolate()->PrintWithTimestamp(
71 "[Scavenge] %.2lf%% of the new space capacity reached\n",
72 current_percent);
73 heap_.isolate()->PrintWithTimestamp("[Scavenge] %d%% is the new limit\n",
74 limit_percentage_);
75 }
76
77 has_requested_gc_ = false;
78 }
79
MaxNewSpaceSizeReached() const80 double StressScavengeObserver::MaxNewSpaceSizeReached() const {
81 return max_new_space_size_reached_;
82 }
83
NextLimit(int min)84 int StressScavengeObserver::NextLimit(int min) {
85 int max = FLAG_stress_scavenge;
86 if (min >= max) {
87 return max;
88 }
89
90 return min + heap_.isolate()->fuzzer_rng()->NextInt(max - min + 1);
91 }
92
93 } // namespace internal
94 } // namespace v8
95