| // Copyright (C) 2019-2021 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(); |
| } |