1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
// Copyright (C) 2019-2023 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
// { dg-options "-std=gnu++2a" }
// { dg-do run { target c++2a } }
// { dg-add-options libatomic }
#include <atomic>
#include <limits.h>
#include <testsuite_hooks.h>
struct X
{
X() = default;
X(int i) : i(i) { }
bool operator==(int rhs) const { return i == rhs; }
int i;
};
void
test01()
{
X value;
{
const auto mo = std::memory_order_relaxed;
std::atomic_ref<X> a(value);
bool ok = a.is_lock_free();
if constexpr (std::atomic_ref<X>::is_always_lock_free)
VERIFY( ok );
a = X{};
VERIFY( a.load() == 0 );
VERIFY( a.load(mo) == 0 );
a.store(1);
VERIFY( a.load() == 1 );
auto v = a.exchange(2);
VERIFY( a.load() == 2 );
VERIFY( v == 1 );
v = a.exchange(3, mo);
VERIFY( a.load() == 3 );
VERIFY( v == 2 );
auto expected = a.load();
while (!a.compare_exchange_weak(expected, 4, mo, mo))
{ /* weak form can fail spuriously */ }
VERIFY( a.load() == 4 );
VERIFY( expected == 3 );
expected = 1;
ok = a.compare_exchange_weak(expected, 5, mo, mo);
VERIFY( !ok && a.load() == 4 && expected == 4 );
ok = a.compare_exchange_strong(expected, 5, mo, mo);
VERIFY( ok && a.load() == 5 && expected == 4 );
expected = 0;
ok = a.compare_exchange_strong(expected, 3, mo, mo);
VERIFY( !ok && a.load() == 5 && expected == 5 );
while (!a.compare_exchange_weak(expected, 4))
{ /* weak form can fail spuriously */ }
VERIFY( a.load() == 4 && expected == 5 );
expected = a.load();
while (!a.compare_exchange_weak(expected, 6, mo))
{ /* weak form can fail spuriously */ }
VERIFY( a.load() == 6 && expected == 4 );
expected = a.load();
expected.i += 1;
ok = a.compare_exchange_weak(expected, -8);
VERIFY( !ok && a.load() == 6 && expected == 6 );
expected = a.load();
expected.i += 1;
ok = a.compare_exchange_weak(expected, 8, mo);
VERIFY( !ok && a.load() == 6 && expected == 6 );
ok = a.compare_exchange_strong(expected, -6);
VERIFY( ok && a.load() == -6 && expected == 6 );
expected = a.load();
ok = a.compare_exchange_strong(expected, 7, mo);
VERIFY( ok && a.load() == 7 && expected == -6 );
expected = a.load();
expected.i += 1;
ok = a.compare_exchange_strong(expected, 2);
VERIFY( !ok && a.load() == 7 && expected == 7 );
expected = a.load();
expected.i += 1;
ok = a.compare_exchange_strong(expected, 2, mo);
VERIFY( !ok && a.load() == 7 && expected == 7 );
}
VERIFY( value == 7 );
}
void
test02()
{
X i;
std::atomic_ref<X> a0(i);
std::atomic_ref<X> a1(i);
std::atomic_ref<X> a2(a0);
a0 = 42;
VERIFY( a1.load() == 42 );
VERIFY( a2.load() == 42 );
}
int
main()
{
test01();
test02();
}
|
