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 // <mutex>
10 
11 // template <class Mutex> class unique_lock;
12 
13 // bool try_lock();
14 
15 #include <cassert>
16 #include <mutex>
17 #include <system_error>
18 
19 #include "test_macros.h"
20 #include "checking_mutex.h"
21 
22 int main(int, char**) {
23   checking_mutex mux;
24 
25   std::unique_lock<checking_mutex> lock(mux, std::defer_lock_t());
26   assert(lock.try_lock());
27   assert(mux.current_state == checking_mutex::locked_via_try_lock);
28   assert(lock.owns_lock());
29 
30 #ifndef TEST_HAS_NO_EXCEPTIONS
31   try {
32     mux.last_try = checking_mutex::none;
33     TEST_IGNORE_NODISCARD lock.try_lock();
34     assert(false);
35   } catch (std::system_error& e) {
36     assert(mux.last_try == checking_mutex::none);
37     assert(e.code() == std::errc::resource_deadlock_would_occur);
38   }
39 #endif
40 
41   lock.unlock();
42   mux.reject = true;
43 
44   assert(!lock.try_lock());
45   assert(mux.last_try == checking_mutex::locked_via_try_lock);
46 
47   assert(!lock.owns_lock());
48   lock.release();
49 
50 #ifndef TEST_HAS_NO_EXCEPTIONS
51   try {
52     mux.last_try = checking_mutex::none;
53     (void)lock.try_lock();
54     assert(false);
55   } catch (std::system_error& e) {
56     assert(mux.last_try == checking_mutex::none);
57     assert(e.code() == std::errc::operation_not_permitted);
58   }
59 #endif
60 
61   return 0;
62 }
63