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-cstdint "" }
   6 // { dg-require-gthreads "" }
   7
   8 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
   9 //
  10 // This file is part of the GNU ISO C++ Library.  This library is free
  11 // software; you can redistribute it and/or modify it under the
  12 // terms of the GNU General Public License as published by the
  13 // Free Software Foundation; either version 3, or (at your option)
  14 // any later version.
  15
  16 // This library is distributed in the hope that it will be useful,
  17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 // GNU General Public License for more details.
  20
  21 // You should have received a copy of the GNU General Public License along
  22 // with this library; see the file COPYING3.  If not see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 // libstdc++/60966
  26 // This test hangs if std::promise::~promise() destroys the
  27 // shared state before std::promise::set_value() finishes using it.
  28
  29 #include <future>
  30 #include <thread>
  31 #include <vector>
  32
  33 const int THREADS = 10;
  34
  35 void run_task(std::promise<void>* pr)
  36 {
  37   std::this_thread::sleep_for(std::chrono::milliseconds(100));
  38   pr->set_value();
  39 }
  40
  41 int main()
  42 {
  43   std::vector<std::promise<void>*> tasks(THREADS);
  44   std::vector<std::thread> threads(THREADS);
  45   std::vector<std::future<void>> futures(THREADS);
  46
  47   for (int i = 0; i < THREADS; ++i)
  48   {
  49     std::promise<void>* task = new std::promise<void>;
  50     tasks[i] = task;
  51     futures[i] = task->get_future();
  52     threads[i] = std::thread(run_task, task);
  53   }
  54
  55   for (int i = 0; i < THREADS; ++i)
  56   {
  57     // the temporary future releases the state as soon as wait() returns
  58     std::future<void>(std::move(futures[i])).wait();
  59     // state is ready, should now be safe to delete promise, so it
  60     // releases the shared state too
  61     delete tasks[i];
  62   }
  63
  64   for (auto& t : threads)
  65     t.join();
  66 }