#include <unistd.h>
#include "curl/curl.h"

int mycurl_debug(CURL *handle, curl_infotype type, char *data,
                 size_t size, void *userptr)
{
    if(type == CURLINFO_TEXT)
        printf("mycurl_debug[%d]: %s\n", type, data);
    return 0;
}

int main(void)
{
    CURLM *multi_handle;
    CURL *easy_handle;
    CURLMsg *msg;
    const int try_times = 3;
    const char *url = "https://www.example.com/";

    curl_global_init(CURL_GLOBAL_ALL);
    printf("%s\n", curl_version());

    multi_handle = curl_multi_init();

    for(int req_id = 0; req_id < try_times; req_id++) {
        printf("New Request[%d]: %s\n", req_id, url);
        int still_running = 0;
        easy_handle = curl_easy_init();
        curl_easy_setopt(easy_handle, CURLOPT_URL, url);
        curl_easy_setopt(easy_handle, CURLOPT_VERBOSE, 1L);
        curl_easy_setopt(easy_handle, CURLOPT_DEBUGFUNCTION, mycurl_debug);
        curl_multi_add_handle(multi_handle, easy_handle);

        if(req_id == 1) {
            curl_multi_setopt(multi_handle, CURLMOPT_CONNCACHE_STALE, 1L);
            printf("Set CURLMOPT_CONNCACHE_STALE=1 before request[%d]\n", req_id);
        }
        else if(req_id == 2) {
            curl_multi_setopt(multi_handle, CURLMOPT_CONNCACHE_STALE, 0L);
            printf("Set CURLMOPT_CONNCACHE_STALE=0 before request[%d]\n", req_id);
        }

        do {
            int numfds = 0;
            curl_multi_perform(multi_handle, &still_running);
            curl_multi_wait(multi_handle, NULL, 0, 10, &numfds);
        } while(still_running);

        do {
            long num_connects = 0L;
            CURLcode code;
            msg = curl_multi_info_read(multi_handle, &still_running);
            if(!msg)
                break;
            if(msg->msg != CURLMSG_DONE)
                continue;

            curl_easy_getinfo(easy_handle, CURLINFO_NUM_CONNECTS,
                              &num_connects);
            code = msg->data.result;
            curl_multi_remove_handle(multi_handle, easy_handle);
            printf("Request[%d] result %ld, num connects %ld\n",
                   req_id, code, num_connects);
        } while(msg);

        curl_easy_cleanup(easy_handle);
        sleep(1);
    }

    curl_multi_cleanup(multi_handle);
    return 0;
}