An example of a high resolution clock.

hi-res-clock.cpp

#include <stdio.h>
#include <time.h>
#include <errno.h>
#include <string.h>

int main() 
{
    clockid_t clock;
    if(clock_getcpuclockid(0, &clock) != 0) {
        strerror(errno);
        return 1;    
    }

    struct timespec time = {0};

    if(clock_gettime(clock, &time) != 0) {
        strerror(errno);
        return 1;    
    }
    long then = time.tv_nsec;

    if(clock_gettime(clock, &time) != 0) {
        strerror(errno);
        return 1;    
    }
    long now = time.tv_nsec;

    long delta = now - then;
    printf("delta: %ldns\n", delta);

    return 0;
}