libstdc++-v3/testsuite/30_threads/semaphore/try_acquire_until.cc

   1 // Copyright (C) 2020-2021 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++2a" }
  19 // { dg-do run { target c++2a } }
  20 // { dg-require-gthreads "" }
  21 // { dg-additional-options "-pthread" { target pthread } }
  22
  23 #include <semaphore>
  24 #include <chrono>
  25 #include <thread>
  26 #include <atomic>
  27 #include <testsuite_hooks.h>
  28
  29 void test01()
  30 {
  31   using namespace std::chrono_literals;
  32   std::counting_semaphore<10> s(2);
  33   s.acquire();
  34
  35   auto const dur = 250ms;
  36   {
  37     auto const at = std::chrono::system_clock::now() + dur;
  38     auto const t0 = std::chrono::steady_clock::now();
  39     VERIFY( s.try_acquire_until(at) );
  40     auto const diff = std::chrono::steady_clock::now() - t0;
  41     VERIFY( diff < dur );
  42   }
  43
  44   {
  45     auto const at = std::chrono::system_clock::now() + dur;
  46     auto const t0 = std::chrono::steady_clock::now();
  47     VERIFY( !s.try_acquire_until(at) );
  48     auto const diff = std::chrono::steady_clock::now() - t0;
  49     VERIFY( diff >= dur );
  50   }
  51 }
  52
  53 void test02()
  54 {
  55   using namespace std::chrono_literals;
  56   std::binary_semaphore s(1);
  57   std::atomic<int> a(0), b(0);
  58   std::thread t([&] {
  59     a.wait(0);
  60     auto const dur = 250ms;
  61     {
  62       auto const at = std::chrono::system_clock::now() + dur;
  63       VERIFY( !s.try_acquire_until(at) );
  64
  65       b++;
  66       b.notify_one();
  67     }
  68
  69     a.wait(1);
  70     {
  71       auto const at = std::chrono::system_clock::now() + dur;
  72       VERIFY( s.try_acquire_until(at) );
  73     }
  74     b++;
  75     b.notify_one();
  76   });
  77   t.detach();
  78
  79   s.acquire();
  80   a++;
  81   a.notify_one();
  82   b.wait(0);
  83   s.release();
  84   a++;
  85   a.notify_one();
  86
  87   b.wait(1);
  88 }
  89
  90 int main()
  91 {
  92   test01();
  93   test02();
  94 }