tests/stdatomic_test.cpp

   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 <gtest/gtest.h>
  18 // Fool stdatomic.h into not using <atomic>.
  19 #undef _USING_LIBCXX
  20 #include <stdatomic.h>
  21 #include <pthread.h>
  22 #include <stdint.h>
  23
  24 TEST(stdatomic, LOCK_FREE) {
  25   ASSERT_TRUE(ATOMIC_BOOL_LOCK_FREE);
  26   ASSERT_TRUE(ATOMIC_CHAR16_T_LOCK_FREE);
  27   ASSERT_TRUE(ATOMIC_CHAR32_T_LOCK_FREE);
  28   ASSERT_TRUE(ATOMIC_CHAR_LOCK_FREE);
  29   ASSERT_TRUE(ATOMIC_INT_LOCK_FREE);
  30   ASSERT_TRUE(ATOMIC_LLONG_LOCK_FREE);
  31   ASSERT_TRUE(ATOMIC_LONG_LOCK_FREE);
  32   ASSERT_TRUE(ATOMIC_POINTER_LOCK_FREE);
  33   ASSERT_TRUE(ATOMIC_SHORT_LOCK_FREE);
  34   ASSERT_TRUE(ATOMIC_WCHAR_T_LOCK_FREE);
  35 }
  36
  37 TEST(stdatomic, init) {
  38   atomic_int v = ATOMIC_VAR_INIT(123);
  39   ASSERT_EQ(123, atomic_load(&v));
  40
  41   atomic_init(&v, 456);
  42   ASSERT_EQ(456, atomic_load(&v));
  43
  44   atomic_flag f = ATOMIC_FLAG_INIT;
  45   ASSERT_FALSE(atomic_flag_test_and_set(&f));
  46 }
  47
  48 TEST(stdatomic, atomic_thread_fence) {
  49   atomic_thread_fence(memory_order_relaxed);
  50   atomic_thread_fence(memory_order_consume);
  51   atomic_thread_fence(memory_order_acquire);
  52   atomic_thread_fence(memory_order_release);
  53   atomic_thread_fence(memory_order_acq_rel);
  54   atomic_thread_fence(memory_order_seq_cst);
  55 }
  56
  57 TEST(stdatomic, atomic_signal_fence) {
  58   atomic_signal_fence(memory_order_relaxed);
  59   atomic_signal_fence(memory_order_consume);
  60   atomic_signal_fence(memory_order_acquire);
  61   atomic_signal_fence(memory_order_release);
  62   atomic_signal_fence(memory_order_acq_rel);
  63   atomic_signal_fence(memory_order_seq_cst);
  64 }
  65
  66 TEST(stdatomic, atomic_is_lock_free) {
  67   atomic_char small;
  68   ASSERT_TRUE(atomic_is_lock_free(&small));
  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 }
  77
  78 TEST(stdatomic, atomic_flag) {
  79   atomic_flag f = ATOMIC_FLAG_INIT;
  80   ASSERT_FALSE(atomic_flag_test_and_set(&f));
  81   ASSERT_TRUE(atomic_flag_test_and_set(&f));
  82
  83   atomic_flag_clear(&f);
  84
  85   ASSERT_FALSE(atomic_flag_test_and_set_explicit(&f, memory_order_relaxed));
  86   ASSERT_TRUE(atomic_flag_test_and_set_explicit(&f, memory_order_relaxed));
  87
  88   atomic_flag_clear_explicit(&f, memory_order_relaxed);
  89   ASSERT_FALSE(atomic_flag_test_and_set_explicit(&f, memory_order_relaxed));
  90 }
  91
  92 TEST(stdatomic, atomic_store) {
  93   atomic_int i;
  94   atomic_store(&i, 123);
  95   ASSERT_EQ(123, atomic_load(&i));
  96   atomic_store_explicit(&i, 123, memory_order_relaxed);
  97   ASSERT_EQ(123, atomic_load_explicit(&i, memory_order_relaxed));
  98 }
  99
 100 TEST(stdatomic, atomic_exchange) {
 101   atomic_int i;
 102   atomic_store(&i, 123);
 103   ASSERT_EQ(123, atomic_exchange(&i, 456));
 104   ASSERT_EQ(456, atomic_exchange_explicit(&i, 123, memory_order_relaxed));
 105 }
 106
 107 TEST(stdatomic, atomic_compare_exchange) {
 108   atomic_int i;
 109   int expected;
 110
 111   atomic_store(&i, 123);
 112   expected = 123;
 113   ASSERT_TRUE(atomic_compare_exchange_strong(&i, &expected, 456));
 114   ASSERT_FALSE(atomic_compare_exchange_strong(&i, &expected, 456));
 115   ASSERT_EQ(456, expected);
 116
 117   atomic_store(&i, 123);
 118   expected = 123;
 119   ASSERT_TRUE(atomic_compare_exchange_strong_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
 120   ASSERT_FALSE(atomic_compare_exchange_strong_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
 121   ASSERT_EQ(456, expected);
 122
 123   atomic_store(&i, 123);
 124   expected = 123;
 125   ASSERT_TRUE(atomic_compare_exchange_weak(&i, &expected, 456));
 126   ASSERT_FALSE(atomic_compare_exchange_weak(&i, &expected, 456));
 127   ASSERT_EQ(456, expected);
 128
 129   atomic_store(&i, 123);
 130   expected = 123;
 131   ASSERT_TRUE(atomic_compare_exchange_weak_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
 132   ASSERT_FALSE(atomic_compare_exchange_weak_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
 133   ASSERT_EQ(456, expected);
 134 }
 135
 136 TEST(stdatomic, atomic_fetch_add) {
 137   atomic_int i = ATOMIC_VAR_INIT(123);
 138   ASSERT_EQ(123, atomic_fetch_add(&i, 1));
 139   ASSERT_EQ(124, atomic_fetch_add_explicit(&i, 1, memory_order_relaxed));
 140   ASSERT_EQ(125, atomic_load(&i));
 141 }
 142
 143 TEST(stdatomic, atomic_fetch_sub) {
 144   atomic_int i = ATOMIC_VAR_INIT(123);
 145   ASSERT_EQ(123, atomic_fetch_sub(&i, 1));
 146   ASSERT_EQ(122, atomic_fetch_sub_explicit(&i, 1, memory_order_relaxed));
 147   ASSERT_EQ(121, atomic_load(&i));
 148 }
 149
 150 TEST(stdatomic, atomic_fetch_or) {
 151   atomic_int i = ATOMIC_VAR_INIT(0x100);
 152   ASSERT_EQ(0x100, atomic_fetch_or(&i, 0x020));
 153   ASSERT_EQ(0x120, atomic_fetch_or_explicit(&i, 0x003, memory_order_relaxed));
 154   ASSERT_EQ(0x123, atomic_load(&i));
 155 }
 156
 157 TEST(stdatomic, atomic_fetch_xor) {
 158   atomic_int i = ATOMIC_VAR_INIT(0x100);
 159   ASSERT_EQ(0x100, atomic_fetch_xor(&i, 0x120));
 160   ASSERT_EQ(0x020, atomic_fetch_xor_explicit(&i, 0x103, memory_order_relaxed));
 161   ASSERT_EQ(0x123, atomic_load(&i));
 162 }
 163
 164 TEST(stdatomic, atomic_fetch_and) {
 165   atomic_int i = ATOMIC_VAR_INIT(0x123);
 166   ASSERT_EQ(0x123, atomic_fetch_and(&i, 0x00f));
 167   ASSERT_EQ(0x003, atomic_fetch_and_explicit(&i, 0x2, memory_order_relaxed));
 168   ASSERT_EQ(0x002, atomic_load(&i));
 169 }
 170
 171 // And a rudimentary test of acquire-release memory ordering:
 172
 173 constexpr static uint_least32_t BIG = 10000000ul; // Assumed even below.
 174
 175 struct three_atomics {
 176   atomic_uint_least32_t x;
 177   char a[123];  // Everything in different cache lines,
 178                 // increase chance of compiler getting alignment wrong.
 179   atomic_uint_least32_t y;
 180   char b[4013];
 181   atomic_uint_least32_t z;
 182 };
 183
 184 // Very simple acquire/release memory ordering sanity check.
 185 static void* writer(void* arg) {
 186   three_atomics* a = reinterpret_cast<three_atomics*>(arg);
 187   for (uint_least32_t i = 0; i <= BIG; i+=2) {
 188     atomic_store_explicit(&a->x, i, memory_order_relaxed);
 189     atomic_store_explicit(&a->z, i, memory_order_relaxed);
 190     atomic_store_explicit(&a->y, i, memory_order_release);
 191     atomic_store_explicit(&a->x, i+1, memory_order_relaxed);
 192     atomic_store_explicit(&a->z, i+1, memory_order_relaxed);
 193     atomic_store_explicit(&a->y, i+1, memory_order_release);
 194   }
 195   return 0;
 196 }
 197
 198 static void* reader(void* arg) {
 199   three_atomics* a = reinterpret_cast<three_atomics*>(arg);
 200   uint_least32_t xval = 0, yval = 0, zval = 0;
 201   size_t repeat = 0;
 202   size_t repeat_limit = 1000;
 203   while (yval != BIG + 1) {
 204     yval = atomic_load_explicit(&a->y, memory_order_acquire);
 205     zval = atomic_load_explicit(&a->z, memory_order_relaxed);
 206     xval = atomic_load_explicit(&a->x, memory_order_relaxed);
 207     // If we see a given value of y, the immediately preceding
 208     // stores to z and x, or later ones, should also be visible.
 209     if (zval < yval) {
 210       // Cant just ASSERT, since we are in a non-void function.
 211       ADD_FAILURE() << "acquire-release ordering violation: "
 212                     << zval << " < " << yval << ", " << xval << "\n";
 213       return 0; // Only report once.
 214     }
 215     if (xval < yval) {
 216       // Cant just ASSERT, since we are in a non-void function.
 217       ADD_FAILURE() << "acquire-release ordering violation: "
 218                     << xval << " < " << yval << ", " << zval <<  "\n";
 219       return 0; // Only report once.
 220     }
 221     if (repeat < repeat_limit) ++repeat;
 222   }
 223   // The following assertion is not technically guaranteed to hold.
 224   // But if it fails to hold, this test was useless, and we have a
 225   // serious scheduling issue that we should probably know about.
 226   EXPECT_EQ(repeat, repeat_limit);
 227   return 0;
 228 }
 229
 230 TEST(stdatomic, ordering) {
 231   // Run a memory ordering sanity test.
 232   void* result;
 233   three_atomics a;
 234   atomic_init(&a.x, 0ul);
 235   atomic_init(&a.y, 0ul);
 236   atomic_init(&a.z, 0ul);
 237   pthread_t t1,t2;
 238   ASSERT_EQ(0, pthread_create(&t1, 0, reader, &a));
 239   ASSERT_EQ(0, pthread_create(&t2, 0, writer, &a));
 240   ASSERT_EQ(0, pthread_join(t1, &result));
 241   EXPECT_EQ(0, result);
 242   ASSERT_EQ(0, pthread_join(t2, &result));
 243   EXPECT_EQ(0, result);
 244   EXPECT_EQ(atomic_load_explicit(&a.x, memory_order_consume), BIG + 1);
 245   EXPECT_EQ(atomic_load_explicit(&a.y, memory_order_seq_cst), BIG + 1);
 246   EXPECT_EQ(atomic_load(&a.z), BIG + 1);
 247 }