1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <stdatomic.h>
18#include <gtest/gtest.h>
19#include <pthread.h>
20#include <stdint.h>
21
22TEST(stdatomic, LOCK_FREE) {
23  ASSERT_TRUE(ATOMIC_BOOL_LOCK_FREE);
24  ASSERT_TRUE(ATOMIC_CHAR16_T_LOCK_FREE);
25  ASSERT_TRUE(ATOMIC_CHAR32_T_LOCK_FREE);
26  ASSERT_TRUE(ATOMIC_CHAR_LOCK_FREE);
27  ASSERT_TRUE(ATOMIC_INT_LOCK_FREE);
28  ASSERT_TRUE(ATOMIC_LLONG_LOCK_FREE);
29  ASSERT_TRUE(ATOMIC_LONG_LOCK_FREE);
30  ASSERT_TRUE(ATOMIC_POINTER_LOCK_FREE);
31  ASSERT_TRUE(ATOMIC_SHORT_LOCK_FREE);
32  ASSERT_TRUE(ATOMIC_WCHAR_T_LOCK_FREE);
33}
34
35TEST(stdatomic, init) {
36  atomic_int v = ATOMIC_VAR_INIT(123);
37  ASSERT_EQ(123, atomic_load(&v));
38
39  atomic_init(&v, 456);
40  ASSERT_EQ(456, atomic_load(&v));
41
42  atomic_flag f = ATOMIC_FLAG_INIT;
43  ASSERT_FALSE(atomic_flag_test_and_set(&f));
44}
45
46TEST(stdatomic, atomic_thread_fence) {
47  atomic_thread_fence(memory_order_relaxed);
48  atomic_thread_fence(memory_order_consume);
49  atomic_thread_fence(memory_order_acquire);
50  atomic_thread_fence(memory_order_release);
51  atomic_thread_fence(memory_order_acq_rel);
52  atomic_thread_fence(memory_order_seq_cst);
53}
54
55TEST(stdatomic, atomic_signal_fence) {
56  atomic_signal_fence(memory_order_relaxed);
57  atomic_signal_fence(memory_order_consume);
58  atomic_signal_fence(memory_order_acquire);
59  atomic_signal_fence(memory_order_release);
60  atomic_signal_fence(memory_order_acq_rel);
61  atomic_signal_fence(memory_order_seq_cst);
62}
63
64TEST(stdatomic, atomic_is_lock_free) {
65  atomic_char small;
66  ASSERT_TRUE(atomic_is_lock_free(&small));
67#if defined(__clang__) || __GNUC_PREREQ(4, 7)
68  // Otherwise stdatomic.h doesn't handle this.
69  atomic_intmax_t big;
70  // atomic_intmax_t(size = 64) is not lock free on mips32.
71#if defined(__mips__) && !defined(__LP64__)
72  ASSERT_FALSE(atomic_is_lock_free(&big));
73#else
74  ASSERT_TRUE(atomic_is_lock_free(&big));
75#endif
76#endif
77}
78
79TEST(stdatomic, atomic_flag) {
80  atomic_flag f = ATOMIC_FLAG_INIT;
81  ASSERT_FALSE(atomic_flag_test_and_set(&f));
82  ASSERT_TRUE(atomic_flag_test_and_set(&f));
83
84  atomic_flag_clear(&f);
85
86  ASSERT_FALSE(atomic_flag_test_and_set_explicit(&f, memory_order_relaxed));
87  ASSERT_TRUE(atomic_flag_test_and_set_explicit(&f, memory_order_relaxed));
88
89  atomic_flag_clear_explicit(&f, memory_order_relaxed);
90  ASSERT_FALSE(atomic_flag_test_and_set_explicit(&f, memory_order_relaxed));
91}
92
93TEST(stdatomic, atomic_store) {
94  atomic_int i;
95  atomic_store(&i, 123);
96  ASSERT_EQ(123, atomic_load(&i));
97  atomic_store_explicit(&i, 123, memory_order_relaxed);
98  ASSERT_EQ(123, atomic_load_explicit(&i, memory_order_relaxed));
99}
100
101TEST(stdatomic, atomic_exchange) {
102  atomic_int i;
103  atomic_store(&i, 123);
104  ASSERT_EQ(123, atomic_exchange(&i, 456));
105  ASSERT_EQ(456, atomic_exchange_explicit(&i, 123, memory_order_relaxed));
106}
107
108TEST(stdatomic, atomic_compare_exchange) {
109  atomic_int i;
110  int expected;
111
112  atomic_store(&i, 123);
113  expected = 123;
114  ASSERT_TRUE(atomic_compare_exchange_strong(&i, &expected, 456));
115  ASSERT_FALSE(atomic_compare_exchange_strong(&i, &expected, 456));
116  ASSERT_EQ(456, expected);
117
118  atomic_store(&i, 123);
119  expected = 123;
120  ASSERT_TRUE(atomic_compare_exchange_strong_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
121  ASSERT_FALSE(atomic_compare_exchange_strong_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
122  ASSERT_EQ(456, expected);
123
124  atomic_store(&i, 123);
125  expected = 123;
126  ASSERT_TRUE(atomic_compare_exchange_weak(&i, &expected, 456));
127  ASSERT_FALSE(atomic_compare_exchange_weak(&i, &expected, 456));
128  ASSERT_EQ(456, expected);
129
130  atomic_store(&i, 123);
131  expected = 123;
132  ASSERT_TRUE(atomic_compare_exchange_weak_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
133  ASSERT_FALSE(atomic_compare_exchange_weak_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
134  ASSERT_EQ(456, expected);
135}
136
137TEST(stdatomic, atomic_fetch_add) {
138  atomic_int i = ATOMIC_VAR_INIT(123);
139  ASSERT_EQ(123, atomic_fetch_add(&i, 1));
140  ASSERT_EQ(124, atomic_fetch_add_explicit(&i, 1, memory_order_relaxed));
141  ASSERT_EQ(125, atomic_load(&i));
142}
143
144TEST(stdatomic, atomic_fetch_sub) {
145  atomic_int i = ATOMIC_VAR_INIT(123);
146  ASSERT_EQ(123, atomic_fetch_sub(&i, 1));
147  ASSERT_EQ(122, atomic_fetch_sub_explicit(&i, 1, memory_order_relaxed));
148  ASSERT_EQ(121, atomic_load(&i));
149}
150
151TEST(stdatomic, atomic_fetch_or) {
152  atomic_int i = ATOMIC_VAR_INIT(0x100);
153  ASSERT_EQ(0x100, atomic_fetch_or(&i, 0x020));
154  ASSERT_EQ(0x120, atomic_fetch_or_explicit(&i, 0x003, memory_order_relaxed));
155  ASSERT_EQ(0x123, atomic_load(&i));
156}
157
158TEST(stdatomic, atomic_fetch_xor) {
159  atomic_int i = ATOMIC_VAR_INIT(0x100);
160  ASSERT_EQ(0x100, atomic_fetch_xor(&i, 0x120));
161  ASSERT_EQ(0x020, atomic_fetch_xor_explicit(&i, 0x103, memory_order_relaxed));
162  ASSERT_EQ(0x123, atomic_load(&i));
163}
164
165TEST(stdatomic, atomic_fetch_and) {
166  atomic_int i = ATOMIC_VAR_INIT(0x123);
167  ASSERT_EQ(0x123, atomic_fetch_and(&i, 0x00f));
168  ASSERT_EQ(0x003, atomic_fetch_and_explicit(&i, 0x2, memory_order_relaxed));
169  ASSERT_EQ(0x002, atomic_load(&i));
170}
171
172// And a rudimentary test of acquire-release memory ordering:
173
174constexpr static uint_least32_t BIG = 10000000ul; // Assumed even below.
175
176struct three_atomics {
177  atomic_uint_least32_t x;
178  char a[123];  // Everything in different cache lines,
179                // increase chance of compiler getting alignment wrong.
180  atomic_uint_least32_t y;
181  char b[4013];
182  atomic_uint_least32_t z;
183};
184
185// Very simple acquire/release memory ordering sanity check.
186static void* writer(void* arg) {
187  three_atomics* a = reinterpret_cast<three_atomics*>(arg);
188  for (uint_least32_t i = 0; i <= BIG; i+=2) {
189    atomic_store_explicit(&a->x, i, memory_order_relaxed);
190    atomic_store_explicit(&a->z, i, memory_order_relaxed);
191    atomic_store_explicit(&a->y, i, memory_order_release);
192    atomic_store_explicit(&a->x, i+1, memory_order_relaxed);
193    atomic_store_explicit(&a->z, i+1, memory_order_relaxed);
194    atomic_store_explicit(&a->y, i+1, memory_order_release);
195  }
196  return 0;
197}
198
199static void* reader(void* arg) {
200  three_atomics* a = reinterpret_cast<three_atomics*>(arg);
201  uint_least32_t xval = 0, yval = 0, zval = 0;
202  size_t repeat = 0;
203  size_t repeat_limit = 1000;
204  while (yval != BIG + 1) {
205    yval = atomic_load_explicit(&a->y, memory_order_acquire);
206    zval = atomic_load_explicit(&a->z, memory_order_relaxed);
207    xval = atomic_load_explicit(&a->x, memory_order_relaxed);
208    // If we see a given value of y, the immediately preceding
209    // stores to z and x, or later ones, should also be visible.
210    if (zval < yval) {
211      // Cant just ASSERT, since we are in a non-void function.
212      ADD_FAILURE() << "acquire-release ordering violation: "
213                    << zval << " < " << yval << ", " << xval << "\n";
214      return 0; // Only report once.
215    }
216    if (xval < yval) {
217      // Cant just ASSERT, since we are in a non-void function.
218      ADD_FAILURE() << "acquire-release ordering violation: "
219                    << xval << " < " << yval << ", " << zval <<  "\n";
220      return 0; // Only report once.
221    }
222    if (repeat < repeat_limit) ++repeat;
223  }
224  // The following assertion is not technically guaranteed to hold.
225  // But if it fails to hold, this test was useless, and we have a
226  // serious scheduling issue that we should probably know about.
227  EXPECT_EQ(repeat, repeat_limit);
228  return 0;
229}
230
231TEST(stdatomic, ordering) {
232  // Run a memory ordering sanity test.
233  void* result;
234  three_atomics a;
235  atomic_init(&a.x, 0ul);
236  atomic_init(&a.y, 0ul);
237  atomic_init(&a.z, 0ul);
238  pthread_t t1,t2;
239  ASSERT_EQ(0, pthread_create(&t1, 0, reader, &a));
240  ASSERT_EQ(0, pthread_create(&t2, 0, writer, &a));
241  ASSERT_EQ(0, pthread_join(t1, &result));
242  EXPECT_EQ(0, result);
243  ASSERT_EQ(0, pthread_join(t2, &result));
244  EXPECT_EQ(0, result);
245  EXPECT_EQ(atomic_load_explicit(&a.x, memory_order_consume), BIG + 1);
246  EXPECT_EQ(atomic_load_explicit(&a.y, memory_order_seq_cst), BIG + 1);
247  EXPECT_EQ(atomic_load(&a.z), BIG + 1);
248}
249