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: libcpp-has-no-threads
10 // UNSUPPORTED: c++03, c++11, c++14
11 
12 // <mutex>
13 
14 // template <class ...Mutex> class scoped_lock;
15 
16 // scoped_lock(adopt_lock_t, Mutex&...);
17 
18 #include <mutex>
19 #include <cassert>
20 #include "test_macros.h"
21 
22 struct TestMutex {
23     bool locked = false;
24     TestMutex() = default;
25 
26     void lock() { assert(!locked); locked = true; }
27     bool try_lock() { if (locked) return false; locked = true; return true; }
28     void unlock() { assert(locked); locked = false; }
29 
30     TestMutex(TestMutex const&) = delete;
31     TestMutex& operator=(TestMutex const&) = delete;
32 };
33 
34 int main(int, char**)
35 {
36     {
37         using LG = std::scoped_lock<>;
38         LG lg(std::adopt_lock);
39     }
40     {
41         TestMutex m1;
42         using LG = std::scoped_lock<TestMutex>;
43         m1.lock();
44         {
45             LG lg(std::adopt_lock, m1);
46             assert(m1.locked);
47         }
48         assert(!m1.locked);
49     }
50     {
51         TestMutex m1, m2;
52         using LG = std::scoped_lock<TestMutex, TestMutex>;
53         m1.lock(); m2.lock();
54         {
55             LG lg(std::adopt_lock, m1, m2);
56             assert(m1.locked && m2.locked);
57         }
58         assert(!m1.locked && !m2.locked);
59     }
60     {
61         TestMutex m1, m2, m3;
62         using LG = std::scoped_lock<TestMutex, TestMutex, TestMutex>;
63         m1.lock(); m2.lock(); m3.lock();
64         {
65             LG lg(std::adopt_lock, m1, m2, m3);
66             assert(m1.locked && m2.locked && m3.locked);
67         }
68         assert(!m1.locked && !m2.locked && !m3.locked);
69     }
70 
71 
72   return 0;
73 }
74