xref: /llvm-project/libcxx/test/std/atomics/atomics.ref/fetch_add.pass.cpp (revision 09e3a360581dc36d0820d3fb6da9bd7cfed87b5d)
1 //
2 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
3 // See https://llvm.org/LICENSE.txt for license information.
4 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
5 //
6 //===----------------------------------------------------------------------===//
7 
8 // UNSUPPORTED: c++03, c++11, c++14, c++17
9 // XFAIL: !has-64-bit-atomics
10 
11 // integral-type fetch_add(integral-type, memory_order = memory_order::seq_cst) const noexcept;
12 // floating-point-type fetch_add(floating-point-type, memory_order = memory_order::seq_cst) const noexcept;
13 // T* fetch_add(difference_type, memory_order = memory_order::seq_cst) const noexcept;
14 
15 #include <atomic>
16 #include <cassert>
17 #include <concepts>
18 #include <type_traits>
19 #include <utility>
20 
21 #include "atomic_helpers.h"
22 #include "test_helper.h"
23 #include "test_macros.h"
24 
25 template <typename T>
26 concept has_fetch_add = requires {
27   std::declval<T const>().fetch_add(std::declval<T>());
28   std::declval<T const>().fetch_add(std::declval<T>(), std::declval<std::memory_order>());
29 };
30 
31 template <typename T>
32 struct TestDoesNotHaveFetchAdd {
33   void operator()() const { static_assert(!has_fetch_add<std::atomic_ref<T>>); }
34 };
35 
36 template <typename T>
37 struct TestFetchAdd {
38   void operator()() const {
39     if constexpr (std::is_arithmetic_v<T>) {
40       T x(T(1));
41       std::atomic_ref<T> const a(x);
42 
43       {
44         std::same_as<T> decltype(auto) y = a.fetch_add(T(2));
45         assert(y == T(1));
46         assert(x == T(3));
47         ASSERT_NOEXCEPT(a.fetch_add(T(0)));
48       }
49 
50       {
51         std::same_as<T> decltype(auto) y = a.fetch_add(T(4), std::memory_order_relaxed);
52         assert(y == T(3));
53         assert(x == T(7));
54         ASSERT_NOEXCEPT(a.fetch_add(T(0), std::memory_order_relaxed));
55       }
56     } else if constexpr (std::is_pointer_v<T>) {
57       using U = std::remove_pointer_t<T>;
58       U t[9]  = {};
59       T p{&t[1]};
60       std::atomic_ref<T> const a(p);
61 
62       {
63         std::same_as<T> decltype(auto) y = a.fetch_add(2);
64         assert(y == &t[1]);
65         assert(a == &t[3]);
66         ASSERT_NOEXCEPT(a.fetch_add(0));
67       }
68 
69       {
70         std::same_as<T> decltype(auto) y = a.fetch_add(4, std::memory_order_relaxed);
71         assert(y == &t[3]);
72         assert(a == &t[7]);
73         ASSERT_NOEXCEPT(a.fetch_add(0, std::memory_order_relaxed));
74       }
75     } else {
76       static_assert(std::is_void_v<T>);
77     }
78 
79     // memory_order::release
80     {
81       auto fetch_add = [](std::atomic_ref<T> const& x, T old_val, T new_val) {
82         x.fetch_add(new_val - old_val, std::memory_order::release);
83       };
84       auto load = [](std::atomic_ref<T> const& x) { return x.load(std::memory_order::acquire); };
85       test_acquire_release<T>(fetch_add, load);
86     }
87 
88     // memory_order::seq_cst
89     {
90       auto fetch_add_no_arg = [](std::atomic_ref<T> const& x, T old_val, T new_val) { x.fetch_add(new_val - old_val); };
91       auto fetch_add_with_order = [](std::atomic_ref<T> const& x, T old_val, T new_val) {
92         x.fetch_add(new_val - old_val, std::memory_order::seq_cst);
93       };
94       auto load = [](std::atomic_ref<T> const& x) { return x.load(); };
95       test_seq_cst<T>(fetch_add_no_arg, load);
96       test_seq_cst<T>(fetch_add_with_order, load);
97     }
98   }
99 };
100 
101 int main(int, char**) {
102   TestEachIntegralType<TestFetchAdd>()();
103 
104   TestFetchAdd<float>()();
105   TestFetchAdd<double>()();
106 
107   TestEachPointerType<TestFetchAdd>()();
108 
109   TestDoesNotHaveFetchAdd<bool>()();
110   TestDoesNotHaveFetchAdd<UserAtomicType>()();
111   TestDoesNotHaveFetchAdd<LargeUserAtomicType>()();
112 
113   return 0;
114 }
115