/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <gtest/gtest.h>
// Fool stdatomic.h into not using <atomic>.
#undef _USING_LIBCXX
#include <stdatomic.h>
#include <pthread.h>
#include <stdint.h>
TEST(stdatomic, LOCK_FREE) {
ASSERT_TRUE(ATOMIC_BOOL_LOCK_FREE);
ASSERT_TRUE(ATOMIC_CHAR16_T_LOCK_FREE);
ASSERT_TRUE(ATOMIC_CHAR32_T_LOCK_FREE);
ASSERT_TRUE(ATOMIC_CHAR_LOCK_FREE);
ASSERT_TRUE(ATOMIC_INT_LOCK_FREE);
ASSERT_TRUE(ATOMIC_LLONG_LOCK_FREE);
ASSERT_TRUE(ATOMIC_LONG_LOCK_FREE);
ASSERT_TRUE(ATOMIC_POINTER_LOCK_FREE);
ASSERT_TRUE(ATOMIC_SHORT_LOCK_FREE);
ASSERT_TRUE(ATOMIC_WCHAR_T_LOCK_FREE);
}
TEST(stdatomic, init) {
atomic_int v = ATOMIC_VAR_INIT(123);
ASSERT_EQ(123, atomic_load(&v));
atomic_init(&v, 456);
ASSERT_EQ(456, atomic_load(&v));
atomic_flag f = ATOMIC_FLAG_INIT;
ASSERT_FALSE(atomic_flag_test_and_set(&f));
}
TEST(stdatomic, atomic_thread_fence) {
atomic_thread_fence(memory_order_relaxed);
atomic_thread_fence(memory_order_consume);
atomic_thread_fence(memory_order_acquire);
atomic_thread_fence(memory_order_release);
atomic_thread_fence(memory_order_acq_rel);
atomic_thread_fence(memory_order_seq_cst);
}
TEST(stdatomic, atomic_signal_fence) {
atomic_signal_fence(memory_order_relaxed);
atomic_signal_fence(memory_order_consume);
atomic_signal_fence(memory_order_acquire);
atomic_signal_fence(memory_order_release);
atomic_signal_fence(memory_order_acq_rel);
atomic_signal_fence(memory_order_seq_cst);
}
TEST(stdatomic, atomic_is_lock_free) {
atomic_char small;
ASSERT_TRUE(atomic_is_lock_free(&small));
#if defined(__clang__) || __GNUC_PREREQ(4, 7)
// Otherwise stdatomic.h doesn't handle this.
atomic_intmax_t big;
// atomic_intmax_t(size = 64) is not lock free on mips32.
#if defined(__mips__) && !defined(__LP64__)
ASSERT_FALSE(atomic_is_lock_free(&big));
#else
ASSERT_TRUE(atomic_is_lock_free(&big));
#endif
#endif
}
TEST(stdatomic, atomic_flag) {
atomic_flag f = ATOMIC_FLAG_INIT;
ASSERT_FALSE(atomic_flag_test_and_set(&f));
ASSERT_TRUE(atomic_flag_test_and_set(&f));
atomic_flag_clear(&f);
ASSERT_FALSE(atomic_flag_test_and_set_explicit(&f, memory_order_relaxed));
ASSERT_TRUE(atomic_flag_test_and_set_explicit(&f, memory_order_relaxed));
atomic_flag_clear_explicit(&f, memory_order_relaxed);
ASSERT_FALSE(atomic_flag_test_and_set_explicit(&f, memory_order_relaxed));
}
TEST(stdatomic, atomic_store) {
atomic_int i;
atomic_store(&i, 123);
ASSERT_EQ(123, atomic_load(&i));
atomic_store_explicit(&i, 123, memory_order_relaxed);
ASSERT_EQ(123, atomic_load_explicit(&i, memory_order_relaxed));
}
TEST(stdatomic, atomic_exchange) {
atomic_int i;
atomic_store(&i, 123);
ASSERT_EQ(123, atomic_exchange(&i, 456));
ASSERT_EQ(456, atomic_exchange_explicit(&i, 123, memory_order_relaxed));
}
TEST(stdatomic, atomic_compare_exchange) {
atomic_int i;
int expected;
atomic_store(&i, 123);
expected = 123;
ASSERT_TRUE(atomic_compare_exchange_strong(&i, &expected, 456));
ASSERT_FALSE(atomic_compare_exchange_strong(&i, &expected, 456));
ASSERT_EQ(456, expected);
atomic_store(&i, 123);
expected = 123;
ASSERT_TRUE(atomic_compare_exchange_strong_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
ASSERT_FALSE(atomic_compare_exchange_strong_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
ASSERT_EQ(456, expected);
atomic_store(&i, 123);
expected = 123;
ASSERT_TRUE(atomic_compare_exchange_weak(&i, &expected, 456));
ASSERT_FALSE(atomic_compare_exchange_weak(&i, &expected, 456));
ASSERT_EQ(456, expected);
atomic_store(&i, 123);
expected = 123;
ASSERT_TRUE(atomic_compare_exchange_weak_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
ASSERT_FALSE(atomic_compare_exchange_weak_explicit(&i, &expected, 456, memory_order_relaxed, memory_order_relaxed));
ASSERT_EQ(456, expected);
}
TEST(stdatomic, atomic_fetch_add) {
atomic_int i = ATOMIC_VAR_INIT(123);
ASSERT_EQ(123, atomic_fetch_add(&i, 1));
ASSERT_EQ(124, atomic_fetch_add_explicit(&i, 1, memory_order_relaxed));
ASSERT_EQ(125, atomic_load(&i));
}
TEST(stdatomic, atomic_fetch_sub) {
atomic_int i = ATOMIC_VAR_INIT(123);
ASSERT_EQ(123, atomic_fetch_sub(&i, 1));
ASSERT_EQ(122, atomic_fetch_sub_explicit(&i, 1, memory_order_relaxed));
ASSERT_EQ(121, atomic_load(&i));
}
TEST(stdatomic, atomic_fetch_or) {
atomic_int i = ATOMIC_VAR_INIT(0x100);
ASSERT_EQ(0x100, atomic_fetch_or(&i, 0x020));
ASSERT_EQ(0x120, atomic_fetch_or_explicit(&i, 0x003, memory_order_relaxed));
ASSERT_EQ(0x123, atomic_load(&i));
}
TEST(stdatomic, atomic_fetch_xor) {
atomic_int i = ATOMIC_VAR_INIT(0x100);
ASSERT_EQ(0x100, atomic_fetch_xor(&i, 0x120));
ASSERT_EQ(0x020, atomic_fetch_xor_explicit(&i, 0x103, memory_order_relaxed));
ASSERT_EQ(0x123, atomic_load(&i));
}
TEST(stdatomic, atomic_fetch_and) {
atomic_int i = ATOMIC_VAR_INIT(0x123);
ASSERT_EQ(0x123, atomic_fetch_and(&i, 0x00f));
ASSERT_EQ(0x003, atomic_fetch_and_explicit(&i, 0x2, memory_order_relaxed));
ASSERT_EQ(0x002, atomic_load(&i));
}
// And a rudimentary test of acquire-release memory ordering:
constexpr static uint_least32_t BIG = 10000000ul; // Assumed even below.
struct three_atomics {
atomic_uint_least32_t x;
char a[123]; // Everything in different cache lines,
// increase chance of compiler getting alignment wrong.
atomic_uint_least32_t y;
char b[4013];
atomic_uint_least32_t z;
};
// Very simple acquire/release memory ordering sanity check.
static void* writer(void* arg) {
three_atomics* a = reinterpret_cast<three_atomics*>(arg);
for (uint_least32_t i = 0; i <= BIG; i+=2) {
atomic_store_explicit(&a->x, i, memory_order_relaxed);
atomic_store_explicit(&a->z, i, memory_order_relaxed);
atomic_store_explicit(&a->y, i, memory_order_release);
atomic_store_explicit(&a->x, i+1, memory_order_relaxed);
atomic_store_explicit(&a->z, i+1, memory_order_relaxed);
atomic_store_explicit(&a->y, i+1, memory_order_release);
}
return 0;
}
static void* reader(void* arg) {
three_atomics* a = reinterpret_cast<three_atomics*>(arg);
uint_least32_t xval = 0, yval = 0, zval = 0;
size_t repeat = 0;
size_t repeat_limit = 1000;
while (yval != BIG + 1) {
yval = atomic_load_explicit(&a->y, memory_order_acquire);
zval = atomic_load_explicit(&a->z, memory_order_relaxed);
xval = atomic_load_explicit(&a->x, memory_order_relaxed);
// If we see a given value of y, the immediately preceding
// stores to z and x, or later ones, should also be visible.
if (zval < yval) {
// Cant just ASSERT, since we are in a non-void function.
ADD_FAILURE() << "acquire-release ordering violation: "
<< zval << " < " << yval << ", " << xval << "\n";
return 0; // Only report once.
}
if (xval < yval) {
// Cant just ASSERT, since we are in a non-void function.
ADD_FAILURE() << "acquire-release ordering violation: "
<< xval << " < " << yval << ", " << zval << "\n";
return 0; // Only report once.
}
if (repeat < repeat_limit) ++repeat;
}
// The following assertion is not technically guaranteed to hold.
// But if it fails to hold, this test was useless, and we have a
// serious scheduling issue that we should probably know about.
EXPECT_EQ(repeat, repeat_limit);
return 0;
}
TEST(stdatomic, ordering) {
// Run a memory ordering sanity test.
void* result;
three_atomics a;
atomic_init(&a.x, 0ul);
atomic_init(&a.y, 0ul);
atomic_init(&a.z, 0ul);
pthread_t t1,t2;
ASSERT_EQ(0, pthread_create(&t1, 0, reader, &a));
ASSERT_EQ(0, pthread_create(&t2, 0, writer, &a));
ASSERT_EQ(0, pthread_join(t1, &result));
EXPECT_EQ(0, result);
ASSERT_EQ(0, pthread_join(t2, &result));
EXPECT_EQ(0, result);
EXPECT_EQ(atomic_load_explicit(&a.x, memory_order_consume), BIG + 1);
EXPECT_EQ(atomic_load_explicit(&a.y, memory_order_seq_cst), BIG + 1);
EXPECT_EQ(atomic_load(&a.z), BIG + 1);
}