dnsbench.c

#define _GNU_SOURCE
#define _DARWIN_C_SOURCE
#include <stdio.h>
#include <stdint.h>
#include <limits.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

struct timespec time_start;
uint64_t times = 0;
uint64_t errors = 0;
uint64_t min_time = INT_MAX;
uint64_t max_time = 0;

uint64_t diff_time(struct timespec *start, struct timespec *end){
    uint64_t start_ts = (start->tv_sec * 1000000) + (start->tv_nsec / 1000);
    uint64_t end_ts = (end->tv_sec * 1000000) + (end->tv_nsec / 1000);
    return end_ts - start_ts;
}

int main(){
    struct addrinfo *res;
    struct timespec current_time;
    struct timespec round_start;
    struct timespec round_end;
    time_t last_printed_time = 0;

    clock_gettime(CLOCK_MONOTONIC_RAW, &time_start);

    while(1){
        clock_gettime(CLOCK_MONOTONIC_RAW, &round_start);
        int result = getaddrinfo("www.wongnai.com", NULL, NULL, &res);
        clock_gettime(CLOCK_MONOTONIC_RAW, &round_end);

        times++;
        if(result != 0){
            errors++;
        }

        uint64_t time_diff = diff_time(&round_start, &round_end);
        if(time_diff < min_time){
            min_time = time_diff;
        }
        if(time_diff > max_time){
            max_time = time_diff;
        }

        clock_gettime(CLOCK_MONOTONIC_RAW, &current_time);
        time_t running_time = current_time.tv_sec - time_start.tv_sec;
        if(running_time != last_printed_time && running_time % 5 == 0){
            last_printed_time = running_time;
            printf("Statistics:\n");
            printf("Running time: %ld\n", running_time);
            printf("Qps: %f\n", (float) times / (float) running_time);
            printf("Done: %"PRIu64", Success: %"PRIu64", Failed: %"PRIu64"\n", times, times-errors, errors);
            printf("Max query time: %"PRIu64"μs, min %"PRIu64"μs\n\n", max_time, min_time);
            fflush(stdout);
        }
    }
}