1//===-- Unittests for Atomic ----------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/__support/CPP/atomic.h"
10#include "test/UnitTest/Test.h"
11
12// Tests in this file do not test atomicity as it would require using
13// threads, at which point it becomes a chicken and egg problem.
14
15TEST(LlvmLibcAtomicTest, LoadStore) {
16 LIBC_NAMESPACE::cpp::Atomic<int> aint(123);
17 ASSERT_EQ(aint.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED), 123);
18
19 aint.store(100, LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED);
20 ASSERT_EQ(aint.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED), 100);
21
22 aint = 1234; // Equivalent of store
23 ASSERT_EQ(aint.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED), 1234);
24}
25
26TEST(LlvmLibcAtomicTest, CompareExchangeStrong) {
27 int desired = 123;
28 LIBC_NAMESPACE::cpp::Atomic<int> aint(desired);
29 ASSERT_TRUE(aint.compare_exchange_strong(desired, 100));
30 ASSERT_EQ(aint.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED), 100);
31
32 ASSERT_FALSE(aint.compare_exchange_strong(desired, 100));
33 ASSERT_EQ(aint.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED), 100);
34}
35
36struct alignas(void *) TrivialData {
37 char a;
38 char b;
39 char padding[sizeof(void *) - 2];
40};
41
42TEST(LlvmLibcAtomicTest, TrivialCompositeData) {
43 LIBC_NAMESPACE::cpp::Atomic<TrivialData> data({'a', 'b', {}});
44 ASSERT_EQ(data.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED).a, 'a');
45 ASSERT_EQ(data.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED).b, 'b');
46
47 auto old = data.exchange({'c', 'd', {}});
48 ASSERT_EQ(data.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED).a, 'c');
49 ASSERT_EQ(data.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED).b, 'd');
50 ASSERT_EQ(old.a, 'a');
51 ASSERT_EQ(old.b, 'b');
52}
53
54TEST(LlvmLibcAtomicTest, AtomicRefTest) {
55 int val = 123;
56 LIBC_NAMESPACE::cpp::AtomicRef aint(val);
57 ASSERT_EQ(aint.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED), 123);
58 ASSERT_EQ(aint.fetch_add(1, LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED), 123);
59 aint = 1234;
60 ASSERT_EQ(aint.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED), 1234);
61
62 // Test the implicit construction from pointer.
63 auto fn = [](LIBC_NAMESPACE::cpp::AtomicRef<int> aint) -> int {
64 return aint.load(LIBC_NAMESPACE::cpp::MemoryOrder::RELAXED);
65 };
66 ASSERT_EQ(fn(&val), 1234);
67}
68

source code of libc/test/src/__support/CPP/atomic_test.cpp