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
|
// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/heap/gc-idle-time-handler.h"
#include "src/flags/flags.h"
#include "src/heap/gc-tracer.h"
#include "src/utils/utils.h"
namespace v8 {
namespace internal {
const double GCIdleTimeHandler::kConservativeTimeRatio = 0.9;
const double GCIdleTimeHandler::kHighContextDisposalRate = 100;
void GCIdleTimeHeapState::Print() {
PrintF("contexts_disposed=%d ", contexts_disposed);
PrintF("contexts_disposal_rate=%f ", contexts_disposal_rate);
PrintF("size_of_objects=%zu ", size_of_objects);
PrintF("incremental_marking_stopped=%d ", incremental_marking_stopped);
}
size_t GCIdleTimeHandler::EstimateMarkingStepSize(
double idle_time_in_ms, double marking_speed_in_bytes_per_ms) {
DCHECK_LT(0, idle_time_in_ms);
if (marking_speed_in_bytes_per_ms == 0) {
marking_speed_in_bytes_per_ms = kInitialConservativeMarkingSpeed;
}
double marking_step_size = marking_speed_in_bytes_per_ms * idle_time_in_ms;
if (marking_step_size >= kMaximumMarkingStepSize) {
return kMaximumMarkingStepSize;
}
return static_cast<size_t>(marking_step_size * kConservativeTimeRatio);
}
bool GCIdleTimeHandler::ShouldDoContextDisposalMarkCompact(
int contexts_disposed, double contexts_disposal_rate,
size_t size_of_objects) {
return contexts_disposed > 0 && contexts_disposal_rate > 0 &&
contexts_disposal_rate < kHighContextDisposalRate &&
size_of_objects <= kMaxHeapSizeForContextDisposalMarkCompact;
}
// The following logic is implemented by the controller:
// (1) If we don't have any idle time, do nothing, unless a context was
// disposed, incremental marking is stopped, and the heap is small. Then do
// a full GC.
// (2) If the context disposal rate is high and we cannot perform a full GC,
// we do nothing until the context disposal rate becomes lower.
// (3) If incremental marking is in progress, we perform a marking step.
GCIdleTimeAction GCIdleTimeHandler::Compute(double idle_time_in_ms,
GCIdleTimeHeapState heap_state) {
if (static_cast<int>(idle_time_in_ms) <= 0) {
if (heap_state.incremental_marking_stopped) {
if (ShouldDoContextDisposalMarkCompact(heap_state.contexts_disposed,
heap_state.contexts_disposal_rate,
heap_state.size_of_objects)) {
return GCIdleTimeAction::kFullGC;
}
}
return GCIdleTimeAction::kDone;
}
if (FLAG_incremental_marking && !heap_state.incremental_marking_stopped) {
return GCIdleTimeAction::kIncrementalStep;
}
return GCIdleTimeAction::kDone;
}
bool GCIdleTimeHandler::Enabled() { return FLAG_incremental_marking; }
} // namespace internal
} // namespace v8
|
