wait_until_pred.pass.cpp revision 06086258d3d8c48a916ec51c33e1ad8f46821b81 
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
12// <condition_variable>
13
14// class condition_variable;
15
16// template <class Clock, class Duration, class Predicate>
17//     bool
18//     wait_until(unique_lock<mutex>& lock,
19//                const chrono::time_point<Clock, Duration>& abs_time,
20//                Predicate pred);
21
22#include <condition_variable>
23#include <mutex>
24#include <thread>
25#include <chrono>
26#include <cassert>
27
28struct Clock
29{
30    typedef std::chrono::milliseconds duration;
31    typedef duration::rep             rep;
32    typedef duration::period          period;
33    typedef std::chrono::time_point<Clock> time_point;
34    static const bool is_steady =  true;
35
36    static time_point now()
37    {
38        using namespace std::chrono;
39        return time_point(duration_cast<duration>(
40                steady_clock::now().time_since_epoch()
41                                                 ));
42    }
43};
44
45class Pred
46{
47    int& i_;
48public:
49    explicit Pred(int& i) : i_(i) {}
50
51    bool operator()() {return i_ != 0;}
52};
53
54std::condition_variable cv;
55std::mutex mut;
56
57int test1 = 0;
58int test2 = 0;
59
60int runs = 0;
61
62void f()
63{
64    std::unique_lock<std::mutex> lk(mut);
65    assert(test2 == 0);
66    test1 = 1;
67    cv.notify_one();
68    Clock::time_point t0 = Clock::now();
69    Clock::time_point t = t0 + Clock::duration(250);
70    bool r = cv.wait_until(lk, t, Pred(test2));
71    Clock::time_point t1 = Clock::now();
72    if (runs == 0)
73    {
74        assert(t1 - t0 < Clock::duration(250));
75        assert(test2 != 0);
76        assert(r);
77    }
78    else
79    {
80        assert(t1 - t0 - Clock::duration(250) < Clock::duration(50));
81        assert(test2 == 0);
82        assert(!r);
83    }
84    ++runs;
85}
86
87int main()
88{
89    {
90        std::unique_lock<std::mutex>lk(mut);
91        std::thread t(f);
92        assert(test1 == 0);
93        while (test1 == 0)
94            cv.wait(lk);
95        assert(test1 != 0);
96        test2 = 1;
97        lk.unlock();
98        cv.notify_one();
99        t.join();
100    }
101    test1 = 0;
102    test2 = 0;
103    {
104        std::unique_lock<std::mutex>lk(mut);
105        std::thread t(f);
106        assert(test1 == 0);
107        while (test1 == 0)
108            cv.wait(lk);
109        assert(test1 != 0);
110        lk.unlock();
111        t.join();
112    }
113}
114