//=====================================================
// File   :  portable_timer.hh
// Author :  L. Plagne <laurent.plagne@edf.fr)> from boost lib
// Copyright (C) EDF R&D,  lun sep 30 14:23:17 CEST 2002
//=====================================================
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// 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.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
//  simple_time extracted from the boost library
//
#ifndef _PORTABLE_TIMER_HH
#define _PORTABLE_TIMER_HH

#include <ctime>
#include <cstdlib>

#include <time.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
#include <sys/times.h>


#define USEC_IN_SEC 1000000


//  timer  -------------------------------------------------------------------//

//  A timer object measures CPU time.

// class Portable_Timer
// {
//  public:
//
//   Portable_Timer( void )
//   {
//   }
//
//
//   void start() { m_val = getTime(); }
//
//   void stop() { m_val = getTime() - m_val; }
//
//   double elapsed() { return  m_val; }
//
//   double user_time() { return elapsed(); }
//
//
// private:
//
//   static inline double getTime(void)
//   {
//       struct timeval tv;
//       struct timezone tz;
//       gettimeofday(&tv, &tz);
//       return (double)tv.tv_sec + 1.e-6 * (double)tv.tv_usec;
//   }
//
//   double m_val;
//
// }; // Portable_Timer

class Portable_Timer
{
 public:

  Portable_Timer( void ):_utime_sec_start(-1),
		_utime_usec_start(-1),
		_utime_sec_stop(-1),
		_utime_usec_stop(-1)/*,
        m_prev_cs(-1)*/
  {
  }


  void   start()
  {
    int status=getrusage(RUSAGE_SELF, &resourcesUsage) ;
//     _start_time = std::clock();
    _utime_sec_start  =  resourcesUsage.ru_utime.tv_sec ;
    _utime_usec_start =  resourcesUsage.ru_utime.tv_usec ;
//     m_prev_cs = resourcesUsage.ru_nivcsw;

  }

  void stop()
  {
    int status=getrusage(RUSAGE_SELF, &resourcesUsage) ;
//     _stop_time = std::clock();
    _utime_sec_stop  =  resourcesUsage.ru_utime.tv_sec ;
    _utime_usec_stop =  resourcesUsage.ru_utime.tv_usec ;

//     m_prev_cs = resourcesUsage.ru_nivcsw - m_prev_cs;
//     std::cerr << resourcesUsage.ru_nvcsw << " + " << resourcesUsage.ru_nivcsw << "\n";

  }

  double elapsed()
  {
    return  user_time();//double(_stop_time - _start_time) / CLOCKS_PER_SEC;
  }

  double user_time()
  {
//     std::cout << m_prev_cs << "\n";
    long tot_utime_sec=_utime_sec_stop-_utime_sec_start;
    long tot_utime_usec=_utime_usec_stop-_utime_usec_start;
    return double(tot_utime_sec)+ double(tot_utime_usec)/double(USEC_IN_SEC) ;
  }


private:

  struct rusage resourcesUsage ;

  long _utime_sec_start ;
  long _utime_usec_start ;

  long _utime_sec_stop ;
  long _utime_usec_stop ;

//   long m_prev_cs;

  std::clock_t _start_time;
  std::clock_t _stop_time;

}; // Portable_Timer


#endif  // PORTABLE_TIMER_HPP