test.c

#include "curl/curl.h"

int main(int argc, char** argv)
{
    CURLM *multi = curl_multi_init();
    curl_multi_setopt(multi, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
    curl_multi_setopt(multi, CURLMOPT_MAX_HOST_CONNECTIONS, 4);

    int j, all_done = 0;
    for (j = 0; j < 100 && !all_done; j++) {
        int i;
        CURL *easies[10];
        for (i = 0; i < 10; i++) {
            CURL *easy = curl_easy_init();
            easies[i] = easy;
            if (i % 2 == 0) {
                curl_easy_setopt(easy, CURLOPT_URL, "http://127.0.0.1:81");
                curl_easy_setopt(easy, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_PRIOR_KNOWLEDGE);
            } else {
                curl_easy_setopt(easy, CURLOPT_URL, "http://127.0.0.1:80");
            }

            curl_easy_setopt(easy, CURLOPT_VERBOSE, 1);
            curl_easy_setopt(easy, CURLOPT_TIMEOUT_MS, 1000);

            curl_multi_add_handle(multi, easy);
        }

        int running= 1;
        while (running) {
            int numfds;
            curl_multi_perform(multi, &running);
            curl_multi_wait(multi, NULL, 0, 1000, &numfds);
        }

        for (i = 0; i < 10; i++) {
            long code;
            curl_easy_getinfo(easies[i], CURLINFO_RESPONSE_CODE, &code);
            if (code < 100) {
                all_done = 1;
            }

            curl_multi_remove_handle(multi, easies[i]);
            curl_easy_cleanup(easies[i]);
        }
    }

    curl_multi_cleanup(multi);

    return 0;
}