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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 */

#pragma once

#include <Windows.h>
#include <avrt.h>
#include <optional>
#include <processthreadsapi.h>
#include <thread>
#include <utility>

namespace ableton
{
namespace platforms
{
namespace windows
{

struct ThreadPriority
{
  void setHigh()
  {
    if (moOriginal)
    {
      return;
    }

    DWORD taskIndex = 0;
    HANDLE handle = ::AvSetMmThreadCharacteristicsW(L"Distribution", &taskIndex);
    if (handle)
    {
      ::AvSetMmThreadPriority(handle, AVRT_PRIORITY_HIGH);
      moOriginal = handle;
    }
  }

  void reset()
  {
    if (moOriginal)
    {
      ::AvRevertMmThreadCharacteristics(*moOriginal);
      moOriginal = std::nullopt;
    }
  }

private:
  std::optional<HANDLE> moOriginal;
};

struct ThreadFactory
{
  template <typename Callable, typename... Args>
  static std::thread makeThread(std::string name, Callable&& f, Args&&... args)
  {
    return std::thread(
      [](std::string name, Callable&& f, Args&&... args)
      {
        assert(name.length() < 20);
        wchar_t nativeName[20];
        mbstowcs(nativeName, name.c_str(), name.length() + 1);
        SetThreadDescription(GetCurrentThread(), nativeName);
        f(args...);
      },
      std::move(name),
      std::forward<Callable>(f),
      std::forward<Args>(args)...);
  }
};

} // namespace windows
} // namespace platforms
} // namespace ableton