/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  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
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  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.
 *
 *=========================================================================*/
/*=========================================================================
 *
 *  Portions of this file are subject to the VTK Toolkit Version 3 copyright.
 *
 *  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
 *
 *  For complete copyright, license and disclaimer of warranty information
 *  please refer to the NOTICE file at the top of the ITK source tree.
 *
 *=========================================================================*/
#include "itkPlatformMultiThreader.h"
#include "itkObjectFactory.h"
#include "itksys/SystemTools.hxx"
#include <cstdlib>

namespace itk
{
#if !defined(ITK_LEGACY_REMOVE)
void
PlatformMultiThreader::MultipleMethodExecute()
{
  ThreadIdType thread_loop;

  // obey the global maximum number of threads limit
  if (m_NumberOfWorkUnits > m_GlobalMaximumNumberOfThreads)
  {
    m_NumberOfWorkUnits = m_GlobalMaximumNumberOfThreads;
  }

  for (thread_loop = 0; thread_loop < m_NumberOfWorkUnits; ++thread_loop)
  {
    if (m_MultipleMethod[thread_loop] == (ThreadFunctionType)0)
    {
      itkExceptionMacro("No multiple method set for: " << thread_loop);
    }
  }

  // There is no multi threading, so there is only one thread.
  m_ThreadInfoArray[0].UserData = m_MultipleData[0];
  m_ThreadInfoArray[0].NumberOfWorkUnits = m_NumberOfWorkUnits;
  (m_MultipleMethod[0])((void *)(&m_ThreadInfoArray[0]));
}

ThreadIdType
PlatformMultiThreader::SpawnThread(ThreadFunctionType itkNotUsed(f), void * UserData)
{
  // There is no multi threading, so there is only one thread.
  // This won't work - so give an error message.
  itkExceptionMacro("Cannot spawn thread in a single threaded environment!");
  return -1;
}

void
PlatformMultiThreader::TerminateThread(ThreadIdType WorkUnitID)
{
  // There is no multi threading, so there is only one thread.
  // This won't work - so give an error message.
  itkExceptionMacro("Cannot terminate thread in single threaded environment!");
}
#endif

void
PlatformMultiThreader::SpawnWaitForSingleMethodThread(ThreadProcessIdType itkNotUsed(threadHandle))
{
  // No threading library specified.  Do nothing.  No joining or waiting
  // necessary.
}

ThreadProcessIdType
PlatformMultiThreader::SpawnDispatchSingleMethodThread(PlatformMultiThreader::WorkUnitInfo * itkNotUsed(threadInfo))
{
  // No threading library specified.  Do nothing.  The computation
  // will be run by the main execution thread.
  return 0;
}
} // end namespace itk
