#include <stdio.h>
#include <sys/time.h>
#include <time.h>
#include <math.h>
#include <sched.h>
#include "hist.h"

#define RTPRIO 1

#define START    1000000 /* start time to sleep for in nanoseconds */
#define END     50000000 /* end time to sleep for in nanoseconds */
#define ITER       10000 /* iter time to sleep for in nanoseconds */

main(int argc, char *argv[]) {
  unsigned int numtimes, c1, c2;
  HIST hs;
  double dt, low, hi;
  struct timeval ts, te;
  struct timespec tfs;
  FILE *ofile;

#ifdef RTPRIO

  struct sched_param p;

  p.sched_priority = 20;
  if (sched_setscheduler(0, SCHED_FIFO, &p) < 0) {
    perror("sched_setscheduler failure: RUN WITH PROPER PRIVLEDGES");
  }

#endif /* RTPRIO */


  if (argc != 3) {printf("%s <num times> <output file>\n", argv[0]); exit(-1);}
  numtimes = atoi(argv[1]);
  stats_init();
  low = START/1000.0 - 10000.0;
  if (low < 0.0) low = 0.0;
  hi = END/1000.0 + 20000.0;

  hs = histogram("Sleep Duration(usec)", 1000, low, hi);
  set_outer(100, hs);
  ofile = fopen(argv[2], "w");
  tfs.tv_sec = 0;
  for (c1 = START; c1 <= END; c1 += ITER) {
    printf("c1 : %d\n", c1);
    for (c2 = 0; c2 < numtimes; c2++) {
      tfs.tv_nsec = c1;
      gettimeofday(&ts, NULL);
      if (nanosleep(&tfs, NULL) == -1) {
	perror("nanosleep failed.");
	exit(1);
      }
      gettimeofday(&te, NULL);
      dt = (te.tv_usec - ts.tv_usec);
      dt += (te.tv_sec - ts.tv_sec)*1000000.0;
      record(dt,hs);
      fprintf(ofile, "sleep_duration_actual_usec %8.8g duration_requested_usec %d\n",
	      dt, c1/1000);
    }
  }
  report();
  /*  
  fprintf(ofile, "%8.8g %8.8g %8.8g %8.8g %10d\n",
      hs->tsum/hs->tcount, hs->tmin,hs->tmax,sqrt(table_var(hs)),
      hs->tcount);
  */
  fclose(ofile);

  return 0;
}