MultiMutexesLock.hpp

/*
 * ------------------------------------------------------------------------------------------------------------
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 * Copyright (c) 2018-2020 Lawrence Livermore National Security LLC
 * Copyright (c) 2018-2020 The Board of Trustees of the Leland Stanford Junior University
 * Copyright (c) 2018-2020 TotalEnergies
 * Copyright (c) 2019-     GEOSX Contributors
 * All rights reserved
 *
 * See top level LICENSE, COPYRIGHT, CONTRIBUTORS, NOTICE, and ACKNOWLEDGEMENTS files for details.
 * ------------------------------------------------------------------------------------------------------------
 */
#ifndef MULTIMUTEXESLOCK_HPP
#define MULTIMUTEXESLOCK_HPP
 
#include <mutex>
#include <tuple>
 
#include "codingUtilities/Utilities.hpp"
 
namespace geos
{
 
template< typename ... Mutexes >
class MultiMutexesLock
{
public:
  MultiMutexesLock( Mutexes &... mutexes )
    : m_islocked( false ), m_mutexes( mutexes ... )
  {
    lock();
  }
 
  ~MultiMutexesLock()
  {
    unlock();
  }
 
  void lock()
  {
    if( m_islocked ) return;
    apply( []( auto && ... mutexes ){ std::lock( mutexes ... ); }, m_mutexes );
    m_islocked = true;
  }
 
  void unlock()
  {
    if( !m_islocked ) return;
    forEachArgInTuple( m_mutexes, []( auto & mutex, auto ){ mutex.unlock(); } );
    m_islocked = false;
  }
 
private:
  bool m_islocked;
  std::tuple< Mutexes &... > m_mutexes;
};
 
template< typename ... Mutexes >
auto make_multilock( Mutexes && ... mutexes )
{
  return MultiMutexesLock< Mutexes... >( std::forward< Mutexes >( mutexes )... );
}
}
#endif // MULTIMUTEXESLOCK_HPP