1/* Copyright (c) 2006, Google Inc.
2 * All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * ---
31 * Author: Sanjay Ghemawat
32 */
33
34#include <stdio.h>
35#include "base/logging.h"
36#include "base/atomicops.h"
37
38#define GG_ULONGLONG(x)  static_cast<uint64>(x)
39
40template <class AtomicType>
41static void TestAtomicIncrement() {
42  // For now, we just test single threaded execution
43
44  // use a guard value to make sure the NoBarrier_AtomicIncrement doesn't go
45  // outside the expected address bounds.  This is in particular to
46  // test that some future change to the asm code doesn't cause the
47  // 32-bit NoBarrier_AtomicIncrement doesn't do the wrong thing on 64-bit
48  // machines.
49  struct {
50    AtomicType prev_word;
51    AtomicType count;
52    AtomicType next_word;
53  } s;
54
55  AtomicType prev_word_value, next_word_value;
56  memset(&prev_word_value, 0xFF, sizeof(AtomicType));
57  memset(&next_word_value, 0xEE, sizeof(AtomicType));
58
59  s.prev_word = prev_word_value;
60  s.count = 0;
61  s.next_word = next_word_value;
62
63  ASSERT_EQ(1, base::subtle::NoBarrier_AtomicIncrement(&s.count, 1));
64  ASSERT_EQ(1, s.count);
65  ASSERT_EQ(prev_word_value, s.prev_word);
66  ASSERT_EQ(next_word_value, s.next_word);
67
68  ASSERT_EQ(3, base::subtle::NoBarrier_AtomicIncrement(&s.count, 2));
69  ASSERT_EQ(3, s.count);
70  ASSERT_EQ(prev_word_value, s.prev_word);
71  ASSERT_EQ(next_word_value, s.next_word);
72
73  ASSERT_EQ(6, base::subtle::NoBarrier_AtomicIncrement(&s.count, 3));
74  ASSERT_EQ(6, s.count);
75  ASSERT_EQ(prev_word_value, s.prev_word);
76  ASSERT_EQ(next_word_value, s.next_word);
77
78  ASSERT_EQ(3, base::subtle::NoBarrier_AtomicIncrement(&s.count, -3));
79  ASSERT_EQ(3, s.count);
80  ASSERT_EQ(prev_word_value, s.prev_word);
81  ASSERT_EQ(next_word_value, s.next_word);
82
83  ASSERT_EQ(1, base::subtle::NoBarrier_AtomicIncrement(&s.count, -2));
84  ASSERT_EQ(1, s.count);
85  ASSERT_EQ(prev_word_value, s.prev_word);
86  ASSERT_EQ(next_word_value, s.next_word);
87
88  ASSERT_EQ(0, base::subtle::NoBarrier_AtomicIncrement(&s.count, -1));
89  ASSERT_EQ(0, s.count);
90  ASSERT_EQ(prev_word_value, s.prev_word);
91  ASSERT_EQ(next_word_value, s.next_word);
92
93  ASSERT_EQ(-1, base::subtle::NoBarrier_AtomicIncrement(&s.count, -1));
94  ASSERT_EQ(-1, s.count);
95  ASSERT_EQ(prev_word_value, s.prev_word);
96  ASSERT_EQ(next_word_value, s.next_word);
97
98  ASSERT_EQ(-5, base::subtle::NoBarrier_AtomicIncrement(&s.count, -4));
99  ASSERT_EQ(-5, s.count);
100  ASSERT_EQ(prev_word_value, s.prev_word);
101  ASSERT_EQ(next_word_value, s.next_word);
102
103  ASSERT_EQ(0, base::subtle::NoBarrier_AtomicIncrement(&s.count, 5));
104  ASSERT_EQ(0, s.count);
105  ASSERT_EQ(prev_word_value, s.prev_word);
106  ASSERT_EQ(next_word_value, s.next_word);
107}
108
109
110#define NUM_BITS(T) (sizeof(T) * 8)
111
112
113template <class AtomicType>
114static void TestCompareAndSwap() {
115  AtomicType value = 0;
116  AtomicType prev = base::subtle::NoBarrier_CompareAndSwap(&value, 0, 1);
117  ASSERT_EQ(1, value);
118  ASSERT_EQ(0, prev);
119
120  // Use test value that has non-zero bits in both halves, more for testing
121  // 64-bit implementation on 32-bit platforms.
122  const AtomicType k_test_val = (GG_ULONGLONG(1) <<
123                                 (NUM_BITS(AtomicType) - 2)) + 11;
124  value = k_test_val;
125  prev = base::subtle::NoBarrier_CompareAndSwap(&value, 0, 5);
126  ASSERT_EQ(k_test_val, value);
127  ASSERT_EQ(k_test_val, prev);
128
129  value = k_test_val;
130  prev = base::subtle::NoBarrier_CompareAndSwap(&value, k_test_val, 5);
131  ASSERT_EQ(5, value);
132  ASSERT_EQ(k_test_val, prev);
133}
134
135
136template <class AtomicType>
137static void TestAtomicExchange() {
138  AtomicType value = 0;
139  AtomicType new_value = base::subtle::NoBarrier_AtomicExchange(&value, 1);
140  ASSERT_EQ(1, value);
141  ASSERT_EQ(0, new_value);
142
143  // Use test value that has non-zero bits in both halves, more for testing
144  // 64-bit implementation on 32-bit platforms.
145  const AtomicType k_test_val = (GG_ULONGLONG(1) <<
146                                 (NUM_BITS(AtomicType) - 2)) + 11;
147  value = k_test_val;
148  new_value = base::subtle::NoBarrier_AtomicExchange(&value, k_test_val);
149  ASSERT_EQ(k_test_val, value);
150  ASSERT_EQ(k_test_val, new_value);
151
152  value = k_test_val;
153  new_value = base::subtle::NoBarrier_AtomicExchange(&value, 5);
154  ASSERT_EQ(5, value);
155  ASSERT_EQ(k_test_val, new_value);
156}
157
158
159template <class AtomicType>
160static void TestAtomicIncrementBounds() {
161  // Test increment at the half-width boundary of the atomic type.
162  // It is primarily for testing at the 32-bit boundary for 64-bit atomic type.
163  AtomicType test_val = GG_ULONGLONG(1) << (NUM_BITS(AtomicType) / 2);
164  AtomicType value = test_val - 1;
165  AtomicType new_value = base::subtle::NoBarrier_AtomicIncrement(&value, 1);
166  ASSERT_EQ(test_val, value);
167  ASSERT_EQ(value, new_value);
168
169  base::subtle::NoBarrier_AtomicIncrement(&value, -1);
170  ASSERT_EQ(test_val - 1, value);
171}
172
173// This is a simple sanity check that values are correct. Not testing
174// atomicity
175template <class AtomicType>
176static void TestStore() {
177  const AtomicType kVal1 = static_cast<AtomicType>(0xa5a5a5a5a5a5a5a5LL);
178  const AtomicType kVal2 = static_cast<AtomicType>(-1);
179
180  AtomicType value;
181
182  base::subtle::NoBarrier_Store(&value, kVal1);
183  ASSERT_EQ(kVal1, value);
184  base::subtle::NoBarrier_Store(&value, kVal2);
185  ASSERT_EQ(kVal2, value);
186
187  base::subtle::Acquire_Store(&value, kVal1);
188  ASSERT_EQ(kVal1, value);
189  base::subtle::Acquire_Store(&value, kVal2);
190  ASSERT_EQ(kVal2, value);
191
192  base::subtle::Release_Store(&value, kVal1);
193  ASSERT_EQ(kVal1, value);
194  base::subtle::Release_Store(&value, kVal2);
195  ASSERT_EQ(kVal2, value);
196}
197
198// This is a simple sanity check that values are correct. Not testing
199// atomicity
200template <class AtomicType>
201static void TestLoad() {
202  const AtomicType kVal1 = static_cast<AtomicType>(0xa5a5a5a5a5a5a5a5LL);
203  const AtomicType kVal2 = static_cast<AtomicType>(-1);
204
205  AtomicType value;
206
207  value = kVal1;
208  ASSERT_EQ(kVal1, base::subtle::NoBarrier_Load(&value));
209  value = kVal2;
210  ASSERT_EQ(kVal2, base::subtle::NoBarrier_Load(&value));
211
212  value = kVal1;
213  ASSERT_EQ(kVal1, base::subtle::Acquire_Load(&value));
214  value = kVal2;
215  ASSERT_EQ(kVal2, base::subtle::Acquire_Load(&value));
216
217  value = kVal1;
218  ASSERT_EQ(kVal1, base::subtle::Release_Load(&value));
219  value = kVal2;
220  ASSERT_EQ(kVal2, base::subtle::Release_Load(&value));
221}
222
223template <class AtomicType>
224static void TestAtomicOps() {
225  TestCompareAndSwap<AtomicType>();
226  TestAtomicExchange<AtomicType>();
227  TestAtomicIncrementBounds<AtomicType>();
228  TestStore<AtomicType>();
229  TestLoad<AtomicType>();
230}
231
232int main(int argc, char** argv) {
233  TestAtomicIncrement<AtomicWord>();
234  TestAtomicIncrement<Atomic32>();
235
236  TestAtomicOps<AtomicWord>();
237  TestAtomicOps<Atomic32>();
238
239  // I've commented the Atomic64 tests out for now, because Atomic64
240  // doesn't work on x86 systems that are not compiled to support mmx
241  // registers.  Since I want this project to be as portable as
242  // possible -- that is, not to assume we've compiled for mmx or even
243  // that the processor supports it -- and we don't actually use
244  // Atomic64 anywhere, I've commented it out of the test for now.
245  // (Luckily, if we ever do use Atomic64 by accident, we'll get told
246  // via a compiler error rather than some obscure runtime failure, so
247  // this course of action is safe.)
248  // If we ever *do* want to enable this, try adding -msse (or -mmmx?)
249  // to the CXXFLAGS in Makefile.am.
250#if 0 and defined(BASE_HAS_ATOMIC64)
251  TestAtomicIncrement<base::subtle::Atomic64>();
252  TestAtomicOps<base::subtle::Atomic64>();
253#endif
254
255  printf("PASS\n");
256  return 0;
257}
258