Example to show resolver behavior

resolver.c

#include <curl/curl.h>

#define ARRAYSIZE(x) (sizeof(x)/sizeof(x[0]))

size_t discard_writes(void *p, size_t n, size_t s, void *u) {
  (void) p; (void) u;
  return s * n;
}

int main(void) {
  const char *urls[] = {
    "http://www.google.com/",
    "http://www.google.com/",
    "http://www.google.com/",
    "http://www.google.com/",
  };

  CURLM *curlm;
  CURL *curle[ARRAYSIZE(urls)];
  int active;

  curl_global_init(CURL_GLOBAL_ALL);
  curlm = curl_multi_init();

  for (size_t i = 0; i < ARRAYSIZE(urls); ++i) {
    curle[i] = curl_easy_init();

    curl_easy_setopt(curle[i], CURLOPT_URL, urls[i]);
    curl_easy_setopt(curle[i], CURLOPT_WRITEFUNCTION, discard_writes);

    curl_multi_add_handle(curlm, curle[i]);
  }

  do {
    int n;

    curl_multi_perform(curlm, &active);
    curl_multi_wait(curlm, NULL, 0, 1000, &n);

    while (curl_multi_info_read(curlm, &n));
  } while (active > 0);

  for (size_t i = 0; i < ARRAYSIZE(urls); ++i) {
    curl_multi_remove_handle(curlm, curle[i]);
    curl_easy_cleanup(curle[i]);
  }

  curl_multi_cleanup(curlm);
  curl_global_cleanup();

  return 0;
}