ThreadFactory.hpp

/* Copyright 2021, Ableton AG, Berlin. All rights reserved.
 *
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 *  it under the terms of the GNU General Public License as published by
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 *  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.
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 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
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 *  please contact <link-devs@ableton.com>.
 */

#pragma once

#include <optional>
#include <pthread.h>
#include <thread>
#include <utility>

namespace ableton
{
namespace platforms
{
namespace linux_
{

struct ThreadPriority
{
  void setHigh()
  {
    if (!moOriginal)
    {
      capture();
    }

    sched_param high{};
    high.sched_priority = 35;
    pthread_setschedparam(pthread_self(), SCHED_FIFO, &high);
  }

  void reset()
  {
    if (moOriginal)
    {
      pthread_setschedparam(pthread_self(), moOriginal->first, &moOriginal->second);
      moOriginal = std::nullopt;
    }
  }

private:
  void capture()
  {
    int policy;
    sched_param params;
    const auto result = pthread_getschedparam(pthread_self(), &policy, &params);
    if (result == 0)
    {
      moOriginal = std::make_pair(policy, params);
    }
  }

  std::optional<std::pair<int, sched_param>> moOriginal;
};

struct ThreadFactory
{
  template <typename Callable, typename... Args>
  static std::thread makeThread(std::string name, Callable&& f, Args&&... args)
  {
    auto thread = std::thread(std::forward<Callable>(f), std::forward<Args>(args)...);
    pthread_setname_np(thread.native_handle(), name.c_str());
    return thread;
  }
};

} // namespace linux_
} // namespace platforms
} // namespace ableton