libstdc++-v3/testsuite/30_threads/promise/60966.cc

   1 // { dg-do run }
   2 // { dg-options "-pthread"  }
   3 // { dg-require-effective-target c++11 }
   4 // { dg-require-effective-target pthread }
   5 // { dg-require-gthreads "" }
   6
   7 // Copyright (C) 2014-2020 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 // libstdc++/60966
  25 // This test hangs if std::promise::~promise() destroys the
  26 // shared state before std::promise::set_value() finishes using it.
  27
  28 #include <future>
  29 #include <thread>
  30 #include <vector>
  31
  32 const int THREADS = 10;
  33
  34 void run_task(std::promise<void>* pr)
  35 {
  36   std::this_thread::sleep_for(std::chrono::milliseconds(100));
  37   pr->set_value();
  38 }
  39
  40 int main()
  41 {
  42   std::vector<std::promise<void>*> tasks(THREADS);
  43   std::vector<std::thread> threads(THREADS);
  44   std::vector<std::future<void>> futures(THREADS);
  45
  46   for (int i = 0; i < THREADS; ++i)
  47   {
  48     std::promise<void>* task = new std::promise<void>;
  49     tasks[i] = task;
  50     futures[i] = task->get_future();
  51     threads[i] = std::thread(run_task, task);
  52   }
  53
  54   for (int i = 0; i < THREADS; ++i)
  55   {
  56     // the temporary future releases the state as soon as wait() returns
  57     std::future<void>(std::move(futures[i])).wait();
  58     // state is ready, should now be safe to delete promise, so it
  59     // releases the shared state too
  60     delete tasks[i];
  61   }
  62
  63   for (auto& t : threads)
  64     t.join();
  65 }