#include <sys/time.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream>

using namespace std;

// The iteration count below needs to be in a reasonable range
//   for the specific hardware this program is run on.

static const int ITERATIONS = 500000000;

// This program runs furiously away in a loop, doing nothing in
// particular, chewing up lots of processor time.  It will stop only
// when interrupted or killed.  Every ITERATIONS times through its
// loop it prints a report of how long (in microseconds) it took to do
// the last ITERATIONS iterations.  The time is elapsed (wall clock)
// time, so that it includes not only time this process spent, but
// also time when the processor is busy running other processes.  The
// times are not actually accurate to the microsecond.  Important
// note: when compiling this program, do not tell the compiler to
// optimize the program, since doing so might eliminate the inner loop
// entirely.  -Max Hailperin <max@gustavus.edu> 2007-08-22
   

int main(int argc, char *argv[]){
  while(1){ // Do the timing test repeatedly until killed.
    timeval start, stop;
    
    if(gettimeofday(&start, 0) < 0){ // Get starting time.
      perror("gettimeofday");
      exit(1);
    }
    for(long i = ITERATIONS; i > 0; i--){ // the actual test
      // Do nothing.
    }
    if(gettimeofday(&stop, 0) < 0){ // Get ending time.
      perror("gettimeofday");
      exit(1);
    }
    long diff = stop.tv_sec - start.tv_sec;
    diff *= 1000000; // microseconds per second
    diff += stop.tv_usec - start.tv_usec;
    cout << diff << endl; // Print elapsed time.
  }
}