libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait_until.pass.cpp

   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: no-threads
  10 // ALLOW_RETRIES: 2
  11
  12 // <condition_variable>
  13
  14 // class condition_variable;
  15
  16 // template <class Clock, class Duration>
  17 //   cv_status
  18 //   wait_until(unique_lock<mutex>& lock,
  19 //              const chrono::time_point<Clock, Duration>& abs_time);
  20
  21 #include <condition_variable>
  22 #include <mutex>
  23 #include <thread>
  24 #include <chrono>
  25 #include <cassert>
  26
  27 #include "make_test_thread.h"
  28 #include "test_macros.h"
  29
  30 struct TestClock
  31 {
  32     typedef std::chrono::milliseconds duration;
  33     typedef duration::rep             rep;
  34     typedef duration::period          period;
  35     typedef std::chrono::time_point<TestClock> time_point;
  36     static const bool is_steady =  true;
  37
  38     static time_point now()
  39     {
  40         using namespace std::chrono;
  41         return time_point(duration_cast<duration>(
  42                 steady_clock::now().time_since_epoch()
  43                                                  ));
  44     }
  45 };
  46
  47 std::condition_variable cv;
  48 std::mutex mut;
  49
  50 int test1 = 0;
  51 int test2 = 0;
  52
  53 int runs = 0;
  54
  55 template <typename Clock>
  56 void f()
  57 {
  58     std::unique_lock<std::mutex> lk(mut);
  59     assert(test2 == 0);
  60     test1 = 1;
  61     cv.notify_one();
  62     typename Clock::time_point t0 = Clock::now();
  63     typename Clock::time_point t = t0 + std::chrono::milliseconds(250);
  64     while (test2 == 0 && cv.wait_until(lk, t) == std::cv_status::no_timeout)
  65         ;
  66     typename Clock::time_point t1 = Clock::now();
  67     if (runs == 0)
  68     {
  69         assert(t1 - t0 < std::chrono::milliseconds(250));
  70         assert(test2 != 0);
  71     }
  72     else
  73     {
  74         assert(t1 - t0 - std::chrono::milliseconds(250) < std::chrono::milliseconds(50));
  75         assert(test2 == 0);
  76     }
  77     ++runs;
  78 }
  79
  80 template <typename Clock>
  81 void run_test()
  82 {
  83     runs = 0;
  84     test1 = 0;
  85     test2 = 0;
  86     {
  87         std::unique_lock<std::mutex>lk(mut);
  88         std::thread t = support::make_test_thread(f<Clock>);
  89         assert(test1 == 0);
  90         while (test1 == 0)
  91             cv.wait(lk);
  92         assert(test1 != 0);
  93         test2 = 1;
  94         lk.unlock();
  95         cv.notify_one();
  96         t.join();
  97     }
  98     test1 = 0;
  99     test2 = 0;
 100     {
 101         std::unique_lock<std::mutex>lk(mut);
 102         std::thread t = support::make_test_thread(f<Clock>);
 103         assert(test1 == 0);
 104         while (test1 == 0)
 105             cv.wait(lk);
 106         assert(test1 != 0);
 107         lk.unlock();
 108         t.join();
 109     }
 110 }
 111
 112 int main(int, char**)
 113 {
 114     run_test<TestClock>();
 115     run_test<std::chrono::steady_clock>();
 116     run_test<std::chrono::system_clock>();
 117     return 0;
 118 }