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// { dg-do run }
// { dg-additional-options "-pthread" { target pthread } }
// { dg-require-effective-target c++11 }
// { dg-require-gthreads "" }
// { dg-require-sched-yield "" }
// Copyright (C) 2011-2022 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
#include <condition_variable>
#include <thread>
#include <mutex>
#include <array>
#include <sstream>
struct scoped_thread
{
~scoped_thread() { if (t.joinable()) t.join(); }
std::thread t;
};
int main()
{
typedef std::unique_lock<std::mutex> Lock;
std::mutex m;
std::condition_variable_any cond;
unsigned int product = 0;
const unsigned int count = 10;
// writing to stream causes timing changes which makes deadlock easier
// to reproduce - do not remove
std::ostringstream out;
// create consumers
std::array<scoped_thread, 2> threads;
for (std::size_t i = 0; i < threads.size(); ++i)
threads[i].t
= std::thread( [&]
{
for (unsigned int i = 0; i < count; ++i)
{
std::this_thread::yield();
Lock lock(m);
while(product == 0)
cond.wait(lock);
out << "got product "
<< std::this_thread::get_id()
<< ' ' << product << std::endl;
--product;
}
} );
// single producer
for (std::size_t i = 0; i < threads.size() * count; ++i)
{
std::this_thread::yield();
Lock lock(m);
++product;
out << "setting product " << std::this_thread::get_id()
<< ' ' << product << std::endl;
cond.notify_one();
}
}
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