/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkProcess.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
// .NAME vtkProcess - a process that can be launched by a vtkMultiProcessController
// .SECTION Description
// vtkProcess is an abstract class representing a process that can be launched
// by a vtkMultiProcessController. Concrete classes just have to implement
// Execute() method and make sure it set the proper value in ReturnValue.
//
// .SECTION Example
//  class MyProcess: public vtkProcess
//  ...
//  vtkMultiProcessController *c;
//  MyProcess *p=new MyProcess::New();
//  p->SetArgs(argc,argv); // some parameters specific to the process
//  p->SetX(10.0); // ...
//  c->SetSingleProcess(p);
//  c->SingleMethodExecute();
//  int returnValue=p->GetReturnValue();
//
// .SECTION see also
// vtkMultiProcessController

#ifndef __vtkProcess_h
#define __vtkProcess_h

#include "vtkObject.h"

class vtkMultiProcessController;

class VTK_PARALLEL_EXPORT vtkProcess : public vtkObject
{
public:
  vtkTypeMacro(vtkProcess,vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent);
  
  // Description
  // Entry point of the process.
  // This method is expected to update ReturnValue.
  virtual void Execute()=0;
  
  // Description:
  // Give access to the controller that launched the process.
  // Initial value is NULL.
  vtkMultiProcessController *GetController();
  
  // Description:
  // This method should not be called directly but set by the controller
  // itself.
  void SetController(vtkMultiProcessController *aController);
  
  // Description:
  // Value set at the end of a call to Execute.
  int GetReturnValue();

protected:
  vtkProcess();
  
  vtkMultiProcessController *Controller;
  int ReturnValue;
  
private:
  vtkProcess(const vtkProcess&);  // Not implemented.
  void operator=(const vtkProcess&);  // Not implemented.
};

#endif
