libstdc++-v3/testsuite/util/slow_clock.h

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2018-2020 Free Software Foundation, Inc.
   4
   5 // This library is free software; you can redistribute it and/or
   6 // modify it under the terms of the GNU General Public License as
   7 // published by the Free Software Foundation; either version 3, or (at
   8 // your option) any later version.
   9
  10 // This library is distributed in the hope that it will be useful, but
  11 // WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 // General Public License for more details.
  14
  15 // You should have received a copy of the GNU General Public License
  16 // along with this library; see the file COPYING3.  If not see
  17 // <http://www.gnu.org/licenses/>.
  18
  19
  20 // A clock that ticks at a third of the speed of system_clock that can be used
  21 // to ensure that functions with timeouts don't erroneously return early.
  22
  23 #include <chrono>
  24
  25 struct slow_clock
  26 {
  27   using rep = std::chrono::system_clock::rep;
  28   using period = std::chrono::system_clock::period;
  29   using duration = std::chrono::system_clock::duration;
  30   using time_point = std::chrono::time_point<slow_clock, duration>;
  31   static constexpr bool is_steady = false;
  32
  33   static time_point now()
  34   {
  35     auto real = std::chrono::system_clock::now();
  36     return time_point{real.time_since_epoch() / 3};
  37   }
  38 };