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 // UNSUPPORTED: c++98, c++03
12
13 // <mutex>
14
15 // template <class ...Mutex> class lock_guard;
16
17 // lock_guard(Mutex&..., adopt_lock_t);
18
19 // MODULES_DEFINES: _LIBCPP_ABI_VARIADIC_LOCK_GUARD
20 #define _LIBCPP_ABI_VARIADIC_LOCK_GUARD
21 #include <mutex>
22 #include <cassert>
23
24 struct TestMutex {
25 bool locked = false;
26 TestMutex() = default;
27
lockTestMutex28 void lock() { assert(!locked); locked = true; }
try_lockTestMutex29 bool try_lock() { if (locked) return false; locked = true; return true; }
unlockTestMutex30 void unlock() { assert(locked); locked = false; }
31
32 TestMutex(TestMutex const&) = delete;
33 TestMutex& operator=(TestMutex const&) = delete;
34 };
35
main()36 int main()
37 {
38 {
39 using LG = std::lock_guard<>;
40 LG lg(std::adopt_lock);
41 }
42 {
43 TestMutex m1, m2;
44 using LG = std::lock_guard<TestMutex, TestMutex>;
45 m1.lock(); m2.lock();
46 {
47 LG lg(m1, m2, std::adopt_lock);
48 assert(m1.locked && m2.locked);
49 }
50 assert(!m1.locked && !m2.locked);
51 }
52 {
53 TestMutex m1, m2, m3;
54 using LG = std::lock_guard<TestMutex, TestMutex, TestMutex>;
55 m1.lock(); m2.lock(); m3.lock();
56 {
57 LG lg(m1, m2, m3, std::adopt_lock);
58 assert(m1.locked && m2.locked && m3.locked);
59 }
60 assert(!m1.locked && !m2.locked && !m3.locked);
61 }
62
63 }
64