/* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
/* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */

#include <stdlib.h>
#include <stdio.h>
#include <sys/time.h>
#include <math.h>
#include <pthread.h>

#define OVERHEAD_TIMES  30000

double my_sqrt(double num)
{
    return sqrt(num);
}

pthread_t my_pthread_self(void)
{
    return pthread_self();
}

int main (int argc, char ** argv, char ** envp)
{
    struct timeval tv;
    gettimeofday(&tv, NULL);

    if (argc < 2)
        return -1;

    unsigned long long msec1 = atoll(argv[1]);
    unsigned long long msec2 = tv.tv_sec * 1000000ULL + tv.tv_usec;

    struct timeval tv1, tv2;
    gettimeofday(&tv1, NULL);
    for (int j = 0 ; j < OVERHEAD_TIMES ; j++)
        gettimeofday(&tv, NULL);
    gettimeofday(&tv2, NULL);
    unsigned long long msec3 = tv1.tv_sec * 1000000ULL + tv1.tv_usec;
    unsigned long long msec4 = tv2.tv_sec * 1000000ULL + tv2.tv_usec;
    unsigned long long overhead = (msec4 - msec3) / OVERHEAD_TIMES;

    printf("%llu\n", msec2 - msec1 - overhead);

    my_sqrt(1.0);
    my_sqrt(2.0);
    my_pthread_self();
    return 0;
}