#include <stdio.h>
#include <time.h>
#include <sys/time.h>

void test_gettimeofday()
{
    struct timeval tv;
    struct timezone tz;
    int i = 0;
    for(i = 0; i < 1000000; i++)
        gettimeofday(&tv, &tz);
}

void test_clock()
{
    int i = 0;
    for(i = 0; i < 1000000; i++)
        clock();
}

void test_time()
{
    int i = 0;
    for(i = 0; i < 1000000; i++)
        time(NULL);
}

#define PRINT_COST(f)	do { \
    clock_t __clk_t1, __clk_t2; \
    __clk_t1 = clock(); \
    f(); \
    __clk_t2 = clock(); \
    printf("%s() %0.2fms\n", #f, (double)(__clk_t2 - __clk_t1) / CLOCKS_PER_SEC * 1000); }while(0)

int main()
{
    PRINT_COST(test_gettimeofday);
    PRINT_COST(test_clock);
    PRINT_COST(test_time);
    return 0;
}