libstdc++-v3/testsuite/30_threads/semaphore/try_acquire_posix.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 -pthread" }
  19 // { dg-do run { target c++2a } }
  20 // { dg-require-effective-target pthread }
  21 // { dg-require-gthreads "" }
  22
  23 #include <semaphore>
  24 #ifdef _GLIBCXX_HAVE_POSIX_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::__platform_semaphore s(2);
  34   s._M_acquire();
  35
  36   auto const dur = 250ms;
  37   {
  38     auto const t0 = std::chrono::steady_clock::now();
  39     VERIFY( s._M_try_acquire_for(dur) );
  40     auto const diff = std::chrono::steady_clock::now() - t0;
  41     VERIFY( diff < dur );
  42   }
  43
  44   {
  45     auto const t0 = std::chrono::steady_clock::now();
  46     VERIFY( !s._M_try_acquire_for(dur) );
  47     auto const diff = std::chrono::steady_clock::now() - t0;
  48     VERIFY( diff >= dur );
  49   }
  50 }
  51
  52 void test02()
  53 {
  54   using namespace std::chrono_literals;
  55   std::__platform_semaphore s(1);
  56   std::atomic<int> a(0), b(0);
  57   std::thread t([&] {
  58     a.wait(0);
  59     auto const dur = 250ms;
  60     VERIFY( !s._M_try_acquire_for(dur) );
  61     b++;
  62     b.notify_one();
  63
  64     a.wait(1);
  65     VERIFY( s._M_try_acquire_for(dur) );
  66     b++;
  67     b.notify_one();
  68   });
  69   t.detach();
  70
  71   s._M_acquire();
  72   a++;
  73   a.notify_one();
  74   b.wait(0);
  75   s._M_release(1);
  76   a++;
  77   a.notify_one();
  78
  79   b.wait(1);
  80 }
  81
  82 void test03()
  83 {
  84   using namespace std::chrono_literals;
  85   std::__platform_semaphore s(2);
  86   s._M_acquire();
  87
  88   auto const dur = 250ms;
  89   {
  90     auto const at = std::chrono::system_clock::now() + dur;
  91     auto const t0 = std::chrono::steady_clock::now();
  92     VERIFY( s._M_try_acquire_until(at) );
  93     auto const diff = std::chrono::steady_clock::now() - t0;
  94     VERIFY( diff < dur );
  95   }
  96
  97   {
  98     auto const at = std::chrono::system_clock::now() + dur;
  99     auto const t0 = std::chrono::steady_clock::now();
 100     VERIFY( !s._M_try_acquire_until(at) );
 101     auto const diff = std::chrono::steady_clock::now() - t0;
 102     VERIFY( diff >= dur );
 103   }
 104 }
 105
 106 void test04()
 107 {
 108   using namespace std::chrono_literals;
 109   std::__platform_semaphore s(1);
 110   std::atomic<int> a(0), b(0);
 111   std::thread t([&] {
 112     a.wait(0);
 113     auto const dur = 250ms;
 114     {
 115       auto const at = std::chrono::system_clock::now() + dur;
 116       VERIFY( !s._M_try_acquire_until(at) );
 117
 118       b++;
 119       b.notify_one();
 120     }
 121
 122     a.wait(1);
 123     {
 124       auto const at = std::chrono::system_clock::now() + dur;
 125       VERIFY( s._M_try_acquire_until(at) );
 126     }
 127     b++;
 128     b.notify_one();
 129   });
 130   t.detach();
 131
 132   s._M_acquire();
 133   a++;
 134   a.notify_one();
 135   b.wait(0);
 136   s._M_release(1);
 137   a++;
 138   a.notify_one();
 139
 140   b.wait(1);
 141 }
 142 #endif
 143
 144 int main()
 145 {
 146 #ifdef _GLIBCXX_HAVE_POSIX_SEMAPHORE
 147   test01();
 148   test02();
 149   test03();
 150   test04();
 151 #endif
 152   return 0;
 153 }