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
11 
12 // dylib support for shared_mutex was added in macosx10.12
13 // XFAIL: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11}}
14 
15 // ALLOW_RETRIES: 2
16 
17 // <shared_mutex>
18 
19 // template <class Mutex> class shared_lock;
20 
21 // void lock();
22 
23 #include <shared_mutex>
24 #include <thread>
25 #include <vector>
26 #include <cstdlib>
27 #include <cassert>
28 
29 #include "make_test_thread.h"
30 #include "test_macros.h"
31 
32 std::shared_timed_mutex m;
33 
34 typedef std::chrono::system_clock Clock;
35 typedef Clock::time_point time_point;
36 typedef Clock::duration duration;
37 typedef std::chrono::milliseconds ms;
38 typedef std::chrono::nanoseconds ns;
39 
40 ms WaitTime = ms(250);
41 
42 // Thread sanitizer causes more overhead and will sometimes cause this test
43 // to fail. To prevent this we give Thread sanitizer more time to complete the
44 // test.
45 #if !defined(TEST_HAS_SANITIZERS)
46 ms Tolerance = ms(25);
47 #else
48 ms Tolerance = ms(25 * 5);
49 #endif
50 
51 
52 void f()
53 {
54     std::shared_lock<std::shared_timed_mutex> lk(m, std::defer_lock);
55     time_point t0 = Clock::now();
56     lk.lock();
57     time_point t1 = Clock::now();
58     assert(lk.owns_lock() == true);
59     ns d = t1 - t0 - WaitTime;
60     assert(d < Tolerance);  // within tolerance
61 #ifndef TEST_HAS_NO_EXCEPTIONS
62     try
63     {
64         lk.lock();
65         assert(false);
66     }
67     catch (std::system_error& e)
68     {
69         assert(e.code().value() == EDEADLK);
70     }
71 #endif
72     lk.unlock();
73     lk.release();
74 #ifndef TEST_HAS_NO_EXCEPTIONS
75     try
76     {
77         lk.lock();
78         assert(false);
79     }
80     catch (std::system_error& e)
81     {
82         assert(e.code().value() == EPERM);
83     }
84 #endif
85 }
86 
87 int main(int, char**)
88 {
89     m.lock();
90     std::vector<std::thread> v;
91     for (int i = 0; i < 5; ++i)
92         v.push_back(support::make_test_thread(f));
93     std::this_thread::sleep_for(WaitTime);
94     m.unlock();
95     for (auto& t : v)
96         t.join();
97 
98   return 0;
99 }
100