1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // UNSUPPORTED: libcpp-has-no-threads
11 
12 // <atomic>
13 
14 // struct atomic_flag
15 
16 // void atomic_flag_clear_explicit(volatile atomic_flag*, memory_order);
17 // void atomic_flag_clear_explicit(atomic_flag*, memory_order);
18 
19 #include <atomic>
20 #include <cassert>
21 
main()22 int main()
23 {
24     {
25         std::atomic_flag f = ATOMIC_FLAG_INIT;
26         f.test_and_set();
27         atomic_flag_clear_explicit(&f, std::memory_order_relaxed);
28         assert(f.test_and_set() == 0);
29     }
30     {
31         std::atomic_flag f = ATOMIC_FLAG_INIT;
32         f.test_and_set();
33         atomic_flag_clear_explicit(&f, std::memory_order_release);
34         assert(f.test_and_set() == 0);
35     }
36     {
37         std::atomic_flag f = ATOMIC_FLAG_INIT;
38         f.test_and_set();
39         atomic_flag_clear_explicit(&f, std::memory_order_seq_cst);
40         assert(f.test_and_set() == 0);
41     }
42     {
43         volatile std::atomic_flag f = ATOMIC_FLAG_INIT;
44         f.test_and_set();
45         atomic_flag_clear_explicit(&f, std::memory_order_relaxed);
46         assert(f.test_and_set() == 0);
47     }
48     {
49         volatile std::atomic_flag f = ATOMIC_FLAG_INIT;
50         f.test_and_set();
51         atomic_flag_clear_explicit(&f, std::memory_order_release);
52         assert(f.test_and_set() == 0);
53     }
54     {
55         volatile std::atomic_flag f = ATOMIC_FLAG_INIT;
56         f.test_and_set();
57         atomic_flag_clear_explicit(&f, std::memory_order_seq_cst);
58         assert(f.test_and_set() == 0);
59     }
60 }
61