libstdc++-v3/testsuite/29_atomics/atomic/wait_notify/100334.cc

   1 // { dg-options "-std=gnu++2a" }
   2 // { dg-do run { target c++2a } }
   3 // { dg-require-gthreads "" }
   4 // { dg-additional-options "-pthread" { target pthread } }
   5 // { dg-add-options libatomic }
   6
   7 // Copyright (C) 2021-2023 Free Software Foundation, Inc.
   8 //
   9 // This file is part of the GNU ISO C++ Library.  This library is free
  10 // software; you can redistribute it and/or modify it under the
  11 // terms of the GNU General Public License as published by the
  12 // Free Software Foundation; either version 3, or (at your option)
  13 // any later version.
  14
  15 // This library is distributed in the hope that it will be useful,
  16 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 // GNU General Public License for more details.
  19
  20 // You should have received a copy of the GNU General Public License along
  21 // with this library; see the file COPYING3.  If not see
  22 // <http://www.gnu.org/licenses/>.
  23
  24 #include <atomic>
  25 #include <future>
  26
  27 #include <testsuite_hooks.h>
  28
  29 template <typename T>
  30 struct atomics_sharing_same_waiter
  31 {
  32    std::atomic<T> tmp[49 * 4] = {};
  33    std::atomic<T>* a[4] = {
  34       { &tmp[0] },
  35       { &tmp[16 * 4] },
  36       { &tmp[32 * 4] },
  37       { &tmp[48 * 4] }
  38    };
  39 };
  40
  41 constexpr unsigned key(void * a)
  42 {
  43   constexpr uintptr_t ct = 16;
  44   return (uintptr_t(a) >> 2) % ct;
  45 }
  46
  47 int
  48 main()
  49 {
  50   // all atomic share the same waiter
  51 //  atomics_sharing_same_waiter<char> atomics;
  52   atomics_sharing_same_waiter<char> atomics;
  53   for (auto& atom : atomics.a)
  54   {
  55     atom->store(0);
  56   }
  57
  58   auto a = &std::__detail::__waiter_pool_base::_S_for(reinterpret_cast<char *>(atomics.a[0]));
  59   auto b = &std::__detail::__waiter_pool_base::_S_for(reinterpret_cast<char *>(atomics.a[1]));
  60   VERIFY( a == b );
  61
  62   auto fut0 = std::async(std::launch::async, [&] { atomics.a[0]->wait(0); });
  63   auto fut1 = std::async(std::launch::async, [&] { atomics.a[1]->wait(0); });
  64   auto fut2 = std::async(std::launch::async, [&] { atomics.a[2]->wait(0); });
  65   auto fut3 = std::async(std::launch::async, [&] { atomics.a[3]->wait(0); });
  66
  67   // make sure the all threads already await
  68   std::this_thread::sleep_for(std::chrono::milliseconds{100});
  69
  70   atomics.a[2]->store(1);
  71   atomics.a[2]->notify_one();
  72
  73   VERIFY(std::future_status::timeout == fut0.wait_for(std::chrono::milliseconds{100}));
  74   VERIFY(atomics.a[0]->load() == 0);
  75
  76   VERIFY(std::future_status::timeout == fut1.wait_for(std::chrono::milliseconds{100}));
  77   VERIFY(atomics.a[1]->load() == 0);
  78
  79   VERIFY(std::future_status::ready == fut2.wait_for(std::chrono::milliseconds{100}));
  80   VERIFY(atomics.a[2]->load() == 1);
  81
  82   VERIFY(std::future_status::timeout == fut3.wait_for(std::chrono::milliseconds{100}));
  83   VERIFY(atomics.a[3]->load() == 0);
  84
  85   atomics.a[0]->store(1);
  86   atomics.a[0]->notify_one();
  87   atomics.a[1]->store(1);
  88   atomics.a[1]->notify_one();
  89   atomics.a[3]->store(1);
  90   atomics.a[3]->notify_one();
  91
  92   return 0;
  93 }