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

   1 // Copyright (C) 2020-2022 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 // { dg-add-options libatomic }
  23
  24 #include <semaphore>
  25 #include <chrono>
  26 #include <thread>
  27 #include <atomic>
  28 #include <testsuite_hooks.h>
  29
  30 void test01()
  31 {
  32   using namespace std::chrono_literals;
  33   std::counting_semaphore<10> s(2);
  34   s.acquire();
  35
  36   auto const dur = 250ms;
  37   {
  38     auto const at = std::chrono::system_clock::now() + dur;
  39     auto const t0 = std::chrono::steady_clock::now();
  40     VERIFY( s.try_acquire_until(at) );
  41     auto const diff = std::chrono::steady_clock::now() - t0;
  42     VERIFY( diff < dur );
  43   }
  44
  45   {
  46     auto const at = std::chrono::system_clock::now() + dur;
  47     auto const t0 = std::chrono::steady_clock::now();
  48     VERIFY( !s.try_acquire_until(at) );
  49     auto const diff = std::chrono::steady_clock::now() - t0;
  50     VERIFY( diff >= dur );
  51   }
  52 }
  53
  54 void test02()
  55 {
  56   using namespace std::chrono_literals;
  57   std::binary_semaphore s(1);
  58   std::atomic<int> a(0), b(0);
  59   std::thread t([&] {
  60     a.wait(0);
  61     auto const dur = 250ms;
  62     {
  63       auto const at = std::chrono::system_clock::now() + dur;
  64       VERIFY( !s.try_acquire_until(at) );
  65
  66       b++;
  67       b.notify_one();
  68     }
  69
  70     a.wait(1);
  71     {
  72       auto const at = std::chrono::system_clock::now() + dur;
  73       VERIFY( s.try_acquire_until(at) );
  74     }
  75     b++;
  76     b.notify_one();
  77   });
  78   t.detach();
  79
  80   s.acquire();
  81   a++;
  82   a.notify_one();
  83   b.wait(0);
  84   s.release();
  85   a++;
  86   a.notify_one();
  87
  88   b.wait(1);
  89 }
  90
  91 int main()
  92 {
  93   test01();
  94   test02();
  95 }