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
100
101
102
103
104
105
|
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/metrics/histogram_snapshot_manager.h"
#include <memory>
#include "base/debug/alias.h"
#include "base/debug/crash_logging.h"
#include "base/logging.h"
#include "base/memory/raw_ptr.h"
#include "base/metrics/histogram_flattener.h"
#include "base/metrics/histogram_samples.h"
#include "base/notreached.h"
#include "base/strings/stringprintf.h"
namespace base {
HistogramSnapshotManager::HistogramSnapshotManager(
HistogramFlattener* histogram_flattener)
: histogram_flattener_(histogram_flattener) {
DCHECK(histogram_flattener_);
}
HistogramSnapshotManager::~HistogramSnapshotManager() = default;
void HistogramSnapshotManager::PrepareDeltas(
const std::vector<HistogramBase*>& histograms,
HistogramBase::Flags flags_to_set,
HistogramBase::Flags required_flags) {
for (HistogramBase* const histogram : histograms) {
histogram->SetFlags(flags_to_set);
if (histogram->HasFlags(required_flags)) {
PrepareDelta(histogram);
}
}
}
void HistogramSnapshotManager::PrepareDelta(HistogramBase* histogram) {
std::unique_ptr<HistogramSamples> samples = histogram->SnapshotDelta();
PrepareSamples(histogram, *samples);
}
void HistogramSnapshotManager::PrepareFinalDelta(
const HistogramBase* histogram) {
std::unique_ptr<HistogramSamples> samples = histogram->SnapshotFinalDelta();
PrepareSamples(histogram, *samples);
}
void HistogramSnapshotManager::PrepareSamples(const HistogramBase* histogram,
const HistogramSamples& samples) {
DCHECK(histogram_flattener_);
if (samples.TotalCount() <= 0) {
return;
}
// Crash if we detect that our histograms have been overwritten. This may be
// a fair distance from the memory smasher, but we hope to correlate these
// crashes with other events, such as plugins, or usage patterns, etc.
uint32_t corruption = histogram->FindCorruption(samples);
base::debug::Alias(&corruption);
if (HistogramBase::BUCKET_ORDER_ERROR & corruption) {
// Extract fields useful during debug.
const BucketRanges* ranges =
static_cast<const Histogram*>(histogram)->bucket_ranges();
uint32_t ranges_checksum = ranges->checksum();
uint32_t ranges_calc_checksum = ranges->CalculateChecksum();
int32_t flags = histogram->flags();
// Ensure that compiler keeps around pointers to |histogram| and its
// internal |bucket_ranges_| for any minidumps.
base::debug::Alias(&ranges_checksum);
base::debug::Alias(&ranges_calc_checksum);
base::debug::Alias(&flags);
// TODO(crbug.com/397733765): Clean up crash keys once the bug is fixed.
SCOPED_CRASH_KEY_STRING32("PrepareSamples", "histogram",
histogram->histogram_name());
std::string ranges_string;
for (size_t index = 0; index < ranges->size(); ++index) {
ranges_string += base::StringPrintf("%d ", ranges->range(index));
}
SCOPED_CRASH_KEY_STRING1024("PrepareSamples", "ranges", ranges_string);
// The checksum should have caught this, so crash separately if it didn't.
CHECK_NE(0U, HistogramBase::RANGE_CHECKSUM_ERROR & corruption);
NOTREACHED(); // Crash for the bucket order corruption.
}
// Checksum corruption might not have caused order corruption.
CHECK_EQ(0U, HistogramBase::RANGE_CHECKSUM_ERROR & corruption);
// Note, at this point corruption can only be COUNT_HIGH_ERROR or
// COUNT_LOW_ERROR and they never arise together, so we don't need to extract
// bits from corruption.
if (corruption) {
DLOG(ERROR) << "Histogram: \"" << histogram->histogram_name()
<< "\" has data corruption: " << corruption;
// Don't record corrupt data to metrics services.
return;
}
histogram_flattener_->RecordDelta(*histogram, samples);
}
} // namespace base
|
