/*****************************************************************************/
/*                                                                           */
/*            Copyright (C)           1993-2025         M. Held              */
/*                                                                           */
/* This code is not in the public domain. All rights reserved! Please make   */
/* sure to read the full copyright statement contained in "README.txt" or in */
/* the "main" file of this code, such as "main.cc".                          */
/*                                                                           */
/*****************************************************************************/
/*                                                                           */
/* Written by:  Martin Held                                                  */
/* E-Mail:      held@cs.sbg.ac.at                                            */
/* Fax Mail:    (+43 662) 8044-611                                           */
/* Voice Mail:  (+43 662) 8044-6304                                          */
/* Snail Mail:  Martin Held                                                  */
/*              FB Informatik                                                */
/*              Universitaet Salzburg                                        */
/*              A-5020 Salzburg, Austria                                     */
/*                                                                           */
/*****************************************************************************/

#include "vroni_object.h"

#ifdef NO_CPUTIME

double vroniObject::elapsed()
{
   return 0.0;
}

#else /* ifndef NO_CPUTIME                                                  */

#include <stdio.h>

/*                                                                           */
/* Note: CPUTIME_IN_MILLISECONDS can be defined in the Imakefile by using    */
/*       flag "-DCPUTIME_IN_MILLISECONDS". Same for the other flags.         */
/*                                                                           */
#ifdef CPUTIME_IN_MILLISECONDS 
#include <sys/resource.h>
#ifndef RUSAGE_CHILDREN
#undef CPUTIME_IN_MILLISECONDS 
#endif
#endif


#ifdef CPUTIME_BY_CHRONO
#include <chrono>

/*                                                                           */
/* This procedure computes the CPU time used by the calling process since    */
/* the last call. It is based on the chrono library of C++.                  */
/* Call it before and after the execution of some instructions of your       */
/* program, whose CPU consumption you would like to know. The first value    */
/* returned can be ignored, and the second value gives the actual CPU        */
/* consumption in the form milliseconds.microseconds. (I.e., 12345 microsecs */
/* are returned as 12.345 millisecs.)                                        */
/*                                                                           */
double vroniObject::elapsed()
{
   double cpu_time;

   if (!elapsed_initialized) {
      elapsed_initialized = true;
      start = std::chrono::high_resolution_clock::now();
      cpu_time = 0.0;
   }
   else {
      auto end = std::chrono::high_resolution_clock::now();
      auto diff = end - start;
      cpu_time = std::chrono::duration<double, std::micro>(diff).count() / 1000.0;
      start = end;
   }

   return cpu_time;
}
#else
#ifdef CPUTIME_IN_MILLISECONDS 

/*                                                                           */
/* This procedure computes the CPU time used by the calling process since    */
/* the last call. (The sum of both system and user time is reported.)        */
/* Call it before and after the execution of some instructions of your       */
/* program, whose CPU consumption you would like to know. The first value    */
/* returned can be ignored, and the second value gives the actual CPU        */
/* consumption in the form milliseconds.microseconds. (I.e., 12345 microsecs */
/* are returned as 12.345 millisecs.)                                        */
/*                                                                           */
double vroniObject::elapsed()
{
   double cpu_time;
   unsigned long new_secs, secs, new_usecs, usecs, new_add_secs;
   int getrusage(int who, struct rusage *rusage);
   struct rusage rusage_self, rusage_children;

   getrusage(RUSAGE_SELF, &rusage_self);
   getrusage(RUSAGE_CHILDREN, &rusage_children);

   new_secs  = rusage_self.ru_utime.tv_sec +
               rusage_self.ru_stime.tv_sec +
               rusage_children.ru_utime.tv_sec +
               rusage_children.ru_stime.tv_sec;
   new_usecs = rusage_self.ru_utime.tv_usec +
               rusage_self.ru_stime.tv_usec +
               rusage_children.ru_utime.tv_usec +
               rusage_children.ru_stime.tv_usec;

   if (new_usecs >= 1000000) {
      new_add_secs = new_usecs / 1000000;
      new_usecs -= new_add_secs * 1000000;
      new_secs  += new_add_secs;
   }

   if (total_usecs > new_usecs) {
      secs  = new_secs - total_secs - 1;
      usecs = new_usecs - total_usecs + 1000000;
   }
   else {
      secs  = new_secs - total_secs;
      usecs = new_usecs - total_usecs;
   }
   
   total_secs  = new_secs;
   total_usecs = new_usecs;

   cpu_time = 1.0e3 * (double) secs + 1.0e-3 * (double) usecs;

   return cpu_time;
}




#else /* ifndef CPUTIME_IN_MILLISECONDS                                      */

#ifdef CPUTIME_VIA_CLOCK


#define CLOCK_UNITS 1000.0        /* this could be figured out automatically */

/*                                                                           */
/* This procedure computes the CPU time used by the calling process since    */
/* the last call. (The sum of both system and user time is reported.)        */
/* Call it before and after the execution of some instructions of your       */
/* program, whose CPU consumption you would like to know. The first value    */
/* returned can be ignored, and the second value gives the actual CPU        */
/* consumption in the form milliseconds.microseconds. (I.e., 12345 microsecs */
/* are returned as 12.345 millisecs.)                                        */
/*                                                                           */
double vroniObject::elapsed()
{
   double cpu_time;
   clock_t finish;

#ifndef CLOCKS_PER_SEC
#define CLOCKS_PER_SEC sysconf(_SC_CLK_TCK)
#endif

   if (!elapsed_initialized) {
     total_cpu_time = clock();
     elapsed_initialized = true;
   }
   finish = clock();

   cpu_time = ((double) (finish - total_cpu_time)) * 
      (CLOCK_UNITS / CLOCKS_PER_SEC);
   total_cpu_time = finish;

   return cpu_time;
}
 
#else /* ifndef CPUTIME_IN_MILLISECONDS  ||  CPUTIME_VIA_CLOCK               */


#include <sys/types.h>
#include <sys/times.h>
#include <unistd.h>

/*                                                                           */
/* This procedure computes the CPU time used by the calling process since    */
/* the last call. (The sum of both system and user time is reported.)        */
/* Call it before and after the execution of some instructions of your       */
/* program, whose CPU consumption you would like to know. The first value    */
/* returned can be ignored, and the second value gives the actual CPU        */
/* consumption (in milliseconds).                                            */
/*                                                                           */
double vroniObject::elapsed()
{
   long dummy;
   double cpu_time;
   struct tms buffer;

   if (HZ == 0)  HZ = sysconf(_SC_CLK_TCK);
 
   times(&buffer);
   dummy    = buffer.tms_utime  + buffer.tms_stime + 
              buffer.tms_cutime + buffer.tms_cstime;
   cpu_time = (double) ((dummy - total) * 1000.0) / HZ; 
   total    = dummy;

   return cpu_time;
}

#endif
#endif
#endif
#endif