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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
// Copyright 2019 The TCMalloc Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "tcmalloc/internal/lifetime_predictions.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "tcmalloc/testing/testutil.h"
namespace tcmalloc {
namespace tcmalloc_internal {
namespace {
class LifetimeDatabaseTest : public testing::Test {
protected:
LifetimeDatabase lifetime_database_;
ABSL_ATTRIBUTE_NOINLINE ABSL_ATTRIBUTE_NO_TAIL_CALL LifetimeStats*
AllocateA() {
LifetimeDatabase::Key key;
return lifetime_database_.LookupOrAddLifetimeStats(&key);
}
ABSL_ATTRIBUTE_NOINLINE ABSL_ATTRIBUTE_NO_TAIL_CALL LifetimeStats*
AllocateB() {
LifetimeDatabase::Key key;
return lifetime_database_.LookupOrAddLifetimeStats(&key);
}
ABSL_ATTRIBUTE_NOINLINE ABSL_ATTRIBUTE_NO_TAIL_CALL LifetimeStats*
AllocateWithStacktraceId(int id) {
if (id == 0) {
LifetimeDatabase::Key key;
return lifetime_database_.LookupOrAddLifetimeStats(&key);
} else if (id % 2 == 0) {
return AllocateWithStacktraceId(id / 2);
} else {
return AllocateWithStacktraceId_2(id / 2);
}
}
// Record a sufficiently large number of short-lived allocations to make
// a prediction short-lived, absent any long-lived allocations.
void MakeShortLived(LifetimeStats* stats, bool high_certainty) {
for (int i = 0; i < (high_certainty ? 100 : 2); i++) {
stats->Update(LifetimeStats::Prediction::kShortLived);
}
}
private:
ABSL_ATTRIBUTE_NOINLINE ABSL_ATTRIBUTE_NO_TAIL_CALL LifetimeStats*
AllocateWithStacktraceId_2(int id) {
if (id == 0) {
LifetimeDatabase::Key key;
return lifetime_database_.LookupOrAddLifetimeStats(&key);
} else if (id % 2 == 0) {
return AllocateWithStacktraceId(id / 2);
} else {
return AllocateWithStacktraceId_2(id / 2);
}
}
};
TEST_F(LifetimeDatabaseTest, Basic) {
PRAGMA_NO_UNROLL
for (int i = 0; i < 2; i++) {
LifetimeStats* r1 = AllocateA();
LifetimeStats* r2 = AllocateB();
LifetimeStats* r3 = AllocateB();
ASSERT_NE(nullptr, r1);
ASSERT_NE(nullptr, r2);
ASSERT_NE(nullptr, r3);
// First iteration: set short-lived count.
if (i == 0) {
MakeShortLived(r1, false);
MakeShortLived(r2, true);
} else {
EXPECT_EQ(LifetimeStats::Prediction::kShortLived,
r1->Predict(LifetimeStats::Certainty::kLowCertainty));
EXPECT_EQ(LifetimeStats::Prediction::kLongLived,
r1->Predict(LifetimeStats::Certainty::kHighCertainty));
EXPECT_EQ(LifetimeStats::Prediction::kShortLived,
r2->Predict(LifetimeStats::Certainty::kLowCertainty));
EXPECT_EQ(LifetimeStats::Prediction::kShortLived,
r2->Predict(LifetimeStats::Certainty::kHighCertainty));
EXPECT_EQ(LifetimeStats::Prediction::kLongLived,
r3->Predict(LifetimeStats::Certainty::kLowCertainty));
EXPECT_EQ(LifetimeStats::Prediction::kLongLived,
r3->Predict(LifetimeStats::Certainty::kHighCertainty));
}
lifetime_database_.RemoveLifetimeStatsReference(r1);
lifetime_database_.RemoveLifetimeStatsReference(r2);
lifetime_database_.RemoveLifetimeStatsReference(r3);
}
}
TEST_F(LifetimeDatabaseTest, Eviction) {
const int kEntries = 5 * LifetimeDatabase::kMaxDatabaseSize;
std::vector<LifetimeStats*> refs;
PRAGMA_NO_UNROLL
for (int i = 0; i < kEntries; i++) {
LifetimeStats* r = AllocateWithStacktraceId(i);
refs.push_back(r);
ASSERT_NE(nullptr, r);
if (i < LifetimeDatabase::kMaxDatabaseSize) {
MakeShortLived(r, true);
}
}
// Check that even evicted entries are still accessible due to refcounts.
for (int i = 0; i < kEntries; i++) {
if (i < LifetimeDatabase::kMaxDatabaseSize) {
EXPECT_EQ(LifetimeStats::Prediction::kShortLived,
refs[i]->Predict(LifetimeStats::Certainty::kLowCertainty));
} else {
EXPECT_EQ(LifetimeStats::Prediction::kLongLived,
refs[i]->Predict(LifetimeStats::Certainty::kLowCertainty));
}
}
EXPECT_EQ(LifetimeDatabase::kMaxDatabaseSize, lifetime_database_.size());
EXPECT_EQ(kEntries - LifetimeDatabase::kMaxDatabaseSize,
lifetime_database_.evictions());
uint64_t before_bytes = lifetime_database_.arena_stats()->bytes_allocated;
// Return all of the references, which should drop the remaining refcounts.
for (int i = 0; i < kEntries; i++) {
lifetime_database_.RemoveLifetimeStatsReference(refs[i]);
}
uint64_t after_bytes = lifetime_database_.arena_stats()->bytes_allocated;
// Check that this freed up memory
EXPECT_LT(after_bytes, before_bytes);
}
} // namespace
} // namespace tcmalloc_internal
} // namespace tcmalloc
|
