///////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2017 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Daniel H. Larkin
////////////////////////////////////////////////////////////////////////////////

#ifndef ARANGO_CPU_RELAX_H
#define ARANGO_CPU_RELAX_H 1

#include "Basics/Common.h"
#include "Basics/operating-system.h"

#include <thread>

namespace arangodb {
namespace basics {

////////////////////////////////////////////////////////////////////////////////
/// @brief Function to let CPU relax inside spinlock.
////////////////////////////////////////////////////////////////////////////////
inline void cpu_relax() {
// TODO use <boost/fiber/detail/cpu_relax.hpp> when available (>1.65.0?)
#if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)
#if defined _WIN32
  YieldProcessor();
#else
  asm volatile("pause" ::: "memory");
#endif
#else
  static constexpr std::chrono::microseconds us0{0};
  std::this_thread::sleep_for(us0);
#endif
}

}  // namespace basics
}  // namespace arangodb

#endif