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 
11 // <mutex>
12 
13 // template <class Mutex> class unique_lock;
14 
15 // mutex_type* release() noexcept;
16 
17 #include <mutex>
18 #include <cassert>
19 
20 struct mutex
21 {
22     static int lock_count;
23     static int unlock_count;
24     void lock() {++lock_count;}
25     void unlock() {++unlock_count;}
26 };
27 
28 int mutex::lock_count = 0;
29 int mutex::unlock_count = 0;
30 
31 mutex m;
32 
33 int main(int, char**)
34 {
35     std::unique_lock<mutex> lk(m);
36     assert(lk.mutex() == &m);
37     assert(lk.owns_lock() == true);
38     assert(mutex::lock_count == 1);
39     assert(mutex::unlock_count == 0);
40     assert(lk.release() == &m);
41     assert(lk.mutex() == nullptr);
42     assert(lk.owns_lock() == false);
43     assert(mutex::lock_count == 1);
44     assert(mutex::unlock_count == 0);
45 
46   return 0;
47 }
48