libcxx/test/std/thread/thread.threads/thread.thread.this/sleep_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
  11 // <thread>
  12
  13 // template <class Clock, class Duration>
  14 //   void sleep_until(const chrono::time_point<Clock, Duration>& abs_time);
  15
  16 #include <cassert>
  17 #include <chrono>
  18 #include <cstdlib>
  19 #include <thread>
  20
  21 #include "test_macros.h"
  22
  23 int main(int, char**)
  24 {
  25   typedef std::chrono::system_clock Clock;
  26   typedef Clock::time_point time_point;
  27   std::chrono::milliseconds ms(500);
  28   time_point t0 = Clock::now();
  29   std::this_thread::sleep_until(t0 + ms);
  30   time_point t1 = Clock::now();
  31   // NOTE: Operating systems are (by default) best effort and therefore we may
  32   // have slept longer, perhaps much longer than we requested.
  33   assert(t1 - t0 >= ms);
  34
  35   return 0;
  36 }