1 // Copyright (c) 2011 The Chromium 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 "base/atomicops.h"
6
7 #include <string.h>
8
9 #include "base/port.h"
10 #include "testing/gtest/include/gtest/gtest.h"
11
12 template <class AtomicType>
TestAtomicIncrement()13 static void TestAtomicIncrement() {
14 // For now, we just test single threaded execution
15
16 // use a guard value to make sure the NoBarrier_AtomicIncrement doesn't go
17 // outside the expected address bounds. This is in particular to
18 // test that some future change to the asm code doesn't cause the
19 // 32-bit NoBarrier_AtomicIncrement doesn't do the wrong thing on 64-bit
20 // machines.
21 struct {
22 AtomicType prev_word;
23 AtomicType count;
24 AtomicType next_word;
25 } s;
26
27 AtomicType prev_word_value, next_word_value;
28 memset(&prev_word_value, 0xFF, sizeof(AtomicType));
29 memset(&next_word_value, 0xEE, sizeof(AtomicType));
30
31 s.prev_word = prev_word_value;
32 s.count = 0;
33 s.next_word = next_word_value;
34
35 EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, 1), 1);
36 EXPECT_EQ(s.count, 1);
37 EXPECT_EQ(s.prev_word, prev_word_value);
38 EXPECT_EQ(s.next_word, next_word_value);
39
40 EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, 2), 3);
41 EXPECT_EQ(s.count, 3);
42 EXPECT_EQ(s.prev_word, prev_word_value);
43 EXPECT_EQ(s.next_word, next_word_value);
44
45 EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, 3), 6);
46 EXPECT_EQ(s.count, 6);
47 EXPECT_EQ(s.prev_word, prev_word_value);
48 EXPECT_EQ(s.next_word, next_word_value);
49
50 EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -3), 3);
51 EXPECT_EQ(s.count, 3);
52 EXPECT_EQ(s.prev_word, prev_word_value);
53 EXPECT_EQ(s.next_word, next_word_value);
54
55 EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -2), 1);
56 EXPECT_EQ(s.count, 1);
57 EXPECT_EQ(s.prev_word, prev_word_value);
58 EXPECT_EQ(s.next_word, next_word_value);
59
60 EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -1), 0);
61 EXPECT_EQ(s.count, 0);
62 EXPECT_EQ(s.prev_word, prev_word_value);
63 EXPECT_EQ(s.next_word, next_word_value);
64
65 EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -1), -1);
66 EXPECT_EQ(s.count, -1);
67 EXPECT_EQ(s.prev_word, prev_word_value);
68 EXPECT_EQ(s.next_word, next_word_value);
69
70 EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -4), -5);
71 EXPECT_EQ(s.count, -5);
72 EXPECT_EQ(s.prev_word, prev_word_value);
73 EXPECT_EQ(s.next_word, next_word_value);
74
75 EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, 5), 0);
76 EXPECT_EQ(s.count, 0);
77 EXPECT_EQ(s.prev_word, prev_word_value);
78 EXPECT_EQ(s.next_word, next_word_value);
79 }
80
81
82 #define NUM_BITS(T) (sizeof(T) * 8)
83
84
85 template <class AtomicType>
TestCompareAndSwap()86 static void TestCompareAndSwap() {
87 AtomicType value = 0;
88 AtomicType prev = base::subtle::NoBarrier_CompareAndSwap(&value, 0, 1);
89 EXPECT_EQ(1, value);
90 EXPECT_EQ(0, prev);
91
92 // Use test value that has non-zero bits in both halves, more for testing
93 // 64-bit implementation on 32-bit platforms.
94 const AtomicType k_test_val = (GG_ULONGLONG(1) <<
95 (NUM_BITS(AtomicType) - 2)) + 11;
96 value = k_test_val;
97 prev = base::subtle::NoBarrier_CompareAndSwap(&value, 0, 5);
98 EXPECT_EQ(k_test_val, value);
99 EXPECT_EQ(k_test_val, prev);
100
101 value = k_test_val;
102 prev = base::subtle::NoBarrier_CompareAndSwap(&value, k_test_val, 5);
103 EXPECT_EQ(5, value);
104 EXPECT_EQ(k_test_val, prev);
105 }
106
107
108 template <class AtomicType>
TestAtomicExchange()109 static void TestAtomicExchange() {
110 AtomicType value = 0;
111 AtomicType new_value = base::subtle::NoBarrier_AtomicExchange(&value, 1);
112 EXPECT_EQ(1, value);
113 EXPECT_EQ(0, new_value);
114
115 // Use test value that has non-zero bits in both halves, more for testing
116 // 64-bit implementation on 32-bit platforms.
117 const AtomicType k_test_val = (GG_ULONGLONG(1) <<
118 (NUM_BITS(AtomicType) - 2)) + 11;
119 value = k_test_val;
120 new_value = base::subtle::NoBarrier_AtomicExchange(&value, k_test_val);
121 EXPECT_EQ(k_test_val, value);
122 EXPECT_EQ(k_test_val, new_value);
123
124 value = k_test_val;
125 new_value = base::subtle::NoBarrier_AtomicExchange(&value, 5);
126 EXPECT_EQ(5, value);
127 EXPECT_EQ(k_test_val, new_value);
128 }
129
130
131 template <class AtomicType>
TestAtomicIncrementBounds()132 static void TestAtomicIncrementBounds() {
133 // Test at rollover boundary between int_max and int_min
134 AtomicType test_val = (GG_ULONGLONG(1) <<
135 (NUM_BITS(AtomicType) - 1));
136 AtomicType value = -1 ^ test_val;
137 AtomicType new_value = base::subtle::NoBarrier_AtomicIncrement(&value, 1);
138 EXPECT_EQ(test_val, value);
139 EXPECT_EQ(value, new_value);
140
141 base::subtle::NoBarrier_AtomicIncrement(&value, -1);
142 EXPECT_EQ(-1 ^ test_val, value);
143
144 // Test at 32-bit boundary for 64-bit atomic type.
145 test_val = GG_ULONGLONG(1) << (NUM_BITS(AtomicType) / 2);
146 value = test_val - 1;
147 new_value = base::subtle::NoBarrier_AtomicIncrement(&value, 1);
148 EXPECT_EQ(test_val, value);
149 EXPECT_EQ(value, new_value);
150
151 base::subtle::NoBarrier_AtomicIncrement(&value, -1);
152 EXPECT_EQ(test_val - 1, value);
153 }
154
155 // Return an AtomicType with the value 0xa5a5a5..
156 template <class AtomicType>
TestFillValue()157 static AtomicType TestFillValue() {
158 AtomicType val = 0;
159 memset(&val, 0xa5, sizeof(AtomicType));
160 return val;
161 }
162
163 // This is a simple sanity check that values are correct. Not testing
164 // atomicity
165 template <class AtomicType>
TestStore()166 static void TestStore() {
167 const AtomicType kVal1 = TestFillValue<AtomicType>();
168 const AtomicType kVal2 = static_cast<AtomicType>(-1);
169
170 AtomicType value;
171
172 base::subtle::NoBarrier_Store(&value, kVal1);
173 EXPECT_EQ(kVal1, value);
174 base::subtle::NoBarrier_Store(&value, kVal2);
175 EXPECT_EQ(kVal2, value);
176
177 base::subtle::Acquire_Store(&value, kVal1);
178 EXPECT_EQ(kVal1, value);
179 base::subtle::Acquire_Store(&value, kVal2);
180 EXPECT_EQ(kVal2, value);
181
182 base::subtle::Release_Store(&value, kVal1);
183 EXPECT_EQ(kVal1, value);
184 base::subtle::Release_Store(&value, kVal2);
185 EXPECT_EQ(kVal2, value);
186 }
187
188 // This is a simple sanity check that values are correct. Not testing
189 // atomicity
190 template <class AtomicType>
TestLoad()191 static void TestLoad() {
192 const AtomicType kVal1 = TestFillValue<AtomicType>();
193 const AtomicType kVal2 = static_cast<AtomicType>(-1);
194
195 AtomicType value;
196
197 value = kVal1;
198 EXPECT_EQ(kVal1, base::subtle::NoBarrier_Load(&value));
199 value = kVal2;
200 EXPECT_EQ(kVal2, base::subtle::NoBarrier_Load(&value));
201
202 value = kVal1;
203 EXPECT_EQ(kVal1, base::subtle::Acquire_Load(&value));
204 value = kVal2;
205 EXPECT_EQ(kVal2, base::subtle::Acquire_Load(&value));
206
207 value = kVal1;
208 EXPECT_EQ(kVal1, base::subtle::Release_Load(&value));
209 value = kVal2;
210 EXPECT_EQ(kVal2, base::subtle::Release_Load(&value));
211 }
212
TEST(AtomicOpsTest,Inc)213 TEST(AtomicOpsTest, Inc) {
214 TestAtomicIncrement<base::subtle::Atomic32>();
215 TestAtomicIncrement<base::subtle::AtomicWord>();
216 }
217
TEST(AtomicOpsTest,CompareAndSwap)218 TEST(AtomicOpsTest, CompareAndSwap) {
219 TestCompareAndSwap<base::subtle::Atomic32>();
220 TestCompareAndSwap<base::subtle::AtomicWord>();
221 }
222
TEST(AtomicOpsTest,Exchange)223 TEST(AtomicOpsTest, Exchange) {
224 TestAtomicExchange<base::subtle::Atomic32>();
225 TestAtomicExchange<base::subtle::AtomicWord>();
226 }
227
TEST(AtomicOpsTest,IncrementBounds)228 TEST(AtomicOpsTest, IncrementBounds) {
229 TestAtomicIncrementBounds<base::subtle::Atomic32>();
230 TestAtomicIncrementBounds<base::subtle::AtomicWord>();
231 }
232
TEST(AtomicOpsTest,Store)233 TEST(AtomicOpsTest, Store) {
234 TestStore<base::subtle::Atomic32>();
235 TestStore<base::subtle::AtomicWord>();
236 }
237
TEST(AtomicOpsTest,Load)238 TEST(AtomicOpsTest, Load) {
239 TestLoad<base::subtle::Atomic32>();
240 TestLoad<base::subtle::AtomicWord>();
241 }
242