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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
// 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/threading/thread_local.h"
#include <optional>
#include "base/check_op.h"
#include "base/memory/raw_ptr.h"
#include "base/synchronization/waitable_event.h"
#include "base/test/bind.h"
#include "base/test/gtest_util.h"
#include "base/threading/simple_thread.h"
#include "base/threading/thread.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
namespace {
// A simple helper which sets the given boolean to true on destruction.
class SetTrueOnDestruction {
public:
explicit SetTrueOnDestruction(bool* was_destroyed)
: was_destroyed_(was_destroyed) {
CHECK_NE(was_destroyed, nullptr);
}
SetTrueOnDestruction(const SetTrueOnDestruction&) = delete;
SetTrueOnDestruction& operator=(const SetTrueOnDestruction&) = delete;
~SetTrueOnDestruction() {
EXPECT_FALSE(*was_destroyed_);
*was_destroyed_ = true;
}
private:
const raw_ptr<bool> was_destroyed_;
};
} // namespace
TEST(ThreadLocalTest, ThreadLocalOwnedPointerBasic) {
ThreadLocalOwnedPointer<SetTrueOnDestruction> tls_owned_pointer;
EXPECT_FALSE(tls_owned_pointer.Get());
bool was_destroyed1 = false;
tls_owned_pointer.Set(
std::make_unique<SetTrueOnDestruction>(&was_destroyed1));
EXPECT_FALSE(was_destroyed1);
EXPECT_TRUE(tls_owned_pointer.Get());
bool was_destroyed2 = false;
tls_owned_pointer.Set(
std::make_unique<SetTrueOnDestruction>(&was_destroyed2));
EXPECT_TRUE(was_destroyed1);
EXPECT_FALSE(was_destroyed2);
EXPECT_TRUE(tls_owned_pointer.Get());
tls_owned_pointer.Set(nullptr);
EXPECT_TRUE(was_destroyed1);
EXPECT_TRUE(was_destroyed2);
EXPECT_FALSE(tls_owned_pointer.Get());
}
TEST(ThreadLocalTest, ThreadLocalOwnedPointerFreedOnThreadExit) {
bool tls_was_destroyed = false;
ThreadLocalOwnedPointer<SetTrueOnDestruction> tls_owned_pointer;
Thread thread("TestThread");
thread.Start();
WaitableEvent tls_set;
thread.task_runner()->PostTask(
FROM_HERE, BindLambdaForTesting([&]() {
tls_owned_pointer.Set(
std::make_unique<SetTrueOnDestruction>(&tls_was_destroyed));
tls_set.Signal();
}));
tls_set.Wait();
EXPECT_FALSE(tls_was_destroyed);
thread.Stop();
EXPECT_TRUE(tls_was_destroyed);
}
TEST(ThreadLocalTest, ThreadLocalOwnedPointerCleansUpMainThreadOnDestruction) {
std::optional<ThreadLocalOwnedPointer<SetTrueOnDestruction>>
tls_owned_pointer(std::in_place);
bool tls_was_destroyed_other = false;
Thread thread("TestThread");
thread.Start();
WaitableEvent tls_set;
thread.task_runner()->PostTask(
FROM_HERE, BindLambdaForTesting([&]() {
tls_owned_pointer->Set(
std::make_unique<SetTrueOnDestruction>(&tls_was_destroyed_other));
tls_set.Signal();
}));
tls_set.Wait();
bool tls_was_destroyed_main = false;
tls_owned_pointer->Set(
std::make_unique<SetTrueOnDestruction>(&tls_was_destroyed_main));
EXPECT_FALSE(tls_was_destroyed_other);
EXPECT_FALSE(tls_was_destroyed_main);
// Stopping the thread relinquishes its TLS (as in
// ThreadLocalOwnedPointerFreedOnThreadExit).
thread.Stop();
EXPECT_TRUE(tls_was_destroyed_other);
EXPECT_FALSE(tls_was_destroyed_main);
// Deleting the ThreadLocalOwnedPointer instance on the main thread is allowed
// iff that's the only thread with remaining storage (ref. disallowed use case
// in ThreadLocalOwnedPointerDeathIfDestroyedWithActiveThread below). In that
// case, the storage on the main thread is freed before releasing the TLS
// slot.
tls_owned_pointer.reset();
EXPECT_TRUE(tls_was_destroyed_main);
}
TEST(ThreadLocalTest, ThreadLocalOwnedPointerDeathIfDestroyedWithActiveThread) {
GTEST_FLAG_SET(death_test_style, "threadsafe");
std::optional<ThreadLocalOwnedPointer<int>> tls_owned_pointer(std::in_place);
Thread thread("TestThread");
thread.Start();
WaitableEvent tls_set;
thread.task_runner()->PostTask(
FROM_HERE, BindLambdaForTesting([&]() {
tls_owned_pointer->Set(std::make_unique<int>(1));
tls_set.Signal();
}));
tls_set.Wait();
EXPECT_DCHECK_DEATH({ tls_owned_pointer.reset(); });
}
TEST(ThreadLocalTest, ThreadLocalOwnedPointerMultiThreadedAndStaticStorage) {
constexpr int kNumThreads = 16;
static ThreadLocalOwnedPointer<SetTrueOnDestruction> tls_owned_pointer;
std::array<bool, kNumThreads> were_destroyed{};
std::array<std::unique_ptr<Thread>, kNumThreads> threads;
for (auto& thread : threads) {
thread = std::make_unique<Thread>("TestThread");
thread->Start();
}
for (const auto& thread : threads) {
// Waiting is unnecessary but enhances the likelihood of data races in the
// next steps.
thread->WaitUntilThreadStarted();
}
for (const bool was_destroyed : were_destroyed) {
EXPECT_FALSE(was_destroyed);
}
for (int i = 0; i < kNumThreads; ++i) {
threads[i]->task_runner()->PostTask(
FROM_HERE,
BindOnce(
[](bool* was_destroyed) {
tls_owned_pointer.Set(
std::make_unique<SetTrueOnDestruction>(was_destroyed));
},
&were_destroyed[i]));
}
static bool main_thread_was_destroyed = false;
// Even when the test is run multiple times in the same process: TLS should
// never be destroyed until static uninitialization.
EXPECT_FALSE(main_thread_was_destroyed);
tls_owned_pointer.Set(
std::make_unique<SetTrueOnDestruction>(&main_thread_was_destroyed));
for (const auto& thread : threads) {
thread->Stop();
}
for (const bool was_destroyed : were_destroyed) {
EXPECT_TRUE(was_destroyed);
}
// The main thread's TLS still wasn't destroyed (let the test unfold naturally
// through static uninitialization).
EXPECT_FALSE(main_thread_was_destroyed);
}
} // namespace base
|
