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// <shared_mutex>
11
12// template <class Mutex> class shared_lock;
13
14// explicit shared_lock(mutex_type& m);
15
16#include <shared_mutex>
17#include <thread>
18#include <vector>
19#include <cstdlib>
20#include <cassert>
21
22#if _LIBCPP_STD_VER > 11
23
24std::shared_timed_mutex m;
25
26typedef std::chrono::system_clock Clock;
27typedef Clock::time_point time_point;
28typedef Clock::duration duration;
29typedef std::chrono::milliseconds ms;
30typedef std::chrono::nanoseconds ns;
31
32void f()
33{
34    time_point t0 = Clock::now();
35    time_point t1;
36    {
37    std::shared_lock<std::shared_timed_mutex> ul(m);
38    t1 = Clock::now();
39    }
40    ns d = t1 - t0 - ms(250);
41    assert(d < ms(50));  // within 50ms
42}
43
44void g()
45{
46    time_point t0 = Clock::now();
47    time_point t1;
48    {
49    std::shared_lock<std::shared_timed_mutex> ul(m);
50    t1 = Clock::now();
51    }
52    ns d = t1 - t0;
53    assert(d < ms(50));  // within 50ms
54}
55
56#endif  // _LIBCPP_STD_VER > 11
57
58int main()
59{
60#if _LIBCPP_STD_VER > 11
61    m.lock();
62    std::vector<std::thread> v;
63    for (int i = 0; i < 5; ++i)
64        v.push_back(std::thread(f));
65    std::this_thread::sleep_for(ms(250));
66    m.unlock();
67    for (auto& t : v)
68        t.join();
69    m.lock_shared();
70    for (auto& t : v)
71        t = std::thread(g);
72    std::thread q(f);
73    std::this_thread::sleep_for(ms(250));
74    m.unlock_shared();
75    for (auto& t : v)
76        t.join();
77    q.join();
78#endif  // _LIBCPP_STD_VER > 11
79}
80