1 | //===----------------------------------------------------------------------===// |
---|---|
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 | // UNSUPPORTED: no-threads |
10 | // UNSUPPORTED: c++03, c++11, c++14 |
11 | |
12 | // <shared_mutex> |
13 | |
14 | // class shared_mutex; |
15 | |
16 | // bool try_lock(); |
17 | |
18 | #include <shared_mutex> |
19 | #include <atomic> |
20 | #include <cassert> |
21 | #include <chrono> |
22 | #include <thread> |
23 | |
24 | #include "make_test_thread.h" |
25 | |
26 | int main(int, char**) { |
27 | // Try to exclusive-lock a mutex that is not locked yet. This should succeed. |
28 | { |
29 | std::shared_mutex m; |
30 | bool succeeded = m.try_lock(); |
31 | assert(succeeded); |
32 | m.unlock(); |
33 | } |
34 | |
35 | // Try to exclusive-lock a mutex that is already locked exclusively. This should fail. |
36 | { |
37 | std::shared_mutex m; |
38 | m.lock(); |
39 | |
40 | std::thread t = support::make_test_thread([&] { |
41 | bool succeeded = m.try_lock(); |
42 | assert(!succeeded); |
43 | }); |
44 | t.join(); |
45 | |
46 | m.unlock(); |
47 | } |
48 | |
49 | // Try to exclusive-lock a mutex that is already share-locked. This should fail. |
50 | { |
51 | std::shared_mutex m; |
52 | m.lock_shared(); |
53 | |
54 | std::thread t = support::make_test_thread([&] { |
55 | bool succeeded = m.try_lock(); |
56 | assert(!succeeded); |
57 | }); |
58 | t.join(); |
59 | |
60 | m.unlock_shared(); |
61 | } |
62 | |
63 | return 0; |
64 | } |
65 |