test.c

#include <string.h>
#include <curl/curl.h>
#include <assert.h>
#include <unistd.h>

fd_set wfds;
fd_set rfds;
struct timeval tv;
int maxfd = 0;

int socket_callback(CURL *easy,            /* easy handle */
                                        curl_socket_t s, /* socket */
                                        int what,                /* describes the socket */
                                        void *userp,         /* private callback pointer */
                                        void *socketp)     /* private socket pointer */
{
    FD_CLR(s, &wfds);
    FD_CLR(s, &rfds);

    if (what == CURL_POLL_IN || what == CURL_POLL_INOUT) {
        FD_SET(s, &rfds);
    }
    if (what == CURL_POLL_OUT || what == CURL_POLL_INOUT) {
        FD_SET(s, &wfds);
    }

    if (s > maxfd) { maxfd = s; }

    return 0;
}

int timer_callback(CURLM *multi,        /* multi handle */
                                     long timeout_ms, /* see above */
                                     void *userp)         /* private callback pointer */
{
    if (timeout_ms == -1) {
        tv.tv_sec = 10;
        tv.tv_usec = 0;
    } else {
        tv.tv_sec = timeout_ms / 1000;
        tv.tv_usec = (timeout_ms % 1000) * 1000;
    }
    return 0;
}

static size_t write_cb(char *d, size_t n, size_t l, void *p)
{
    /* take care of the data here, ignored in this example */
    (void)d;
    (void)p;
    return n*l;
}


int main(int argc, char** argv)
{
    int running = 0;
    curl_global_init(CURL_GLOBAL_ALL);

    FD_ZERO(&wfds);
    FD_ZERO(&rfds);

    CURLM *multi = curl_multi_init();
    curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, socket_callback);
    curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, timer_callback);
    curl_multi_setopt(multi, CURLMOPT_MAX_HOST_CONNECTIONS, 4);
    curl_multi_setopt(multi, CURLMOPT_MAXCONNECTS, 128);
    curl_multi_setopt(multi, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);

    int remaining = 50000;
    int done = 0;

    tv.tv_sec = 0;
    tv.tv_usec = 0;

    while (remaining > 0 || running > 0) {
        int i;
        if (running == 0)
          while (running < 100) {
            remaining--;
            running++;
            CURL *easy = curl_easy_init();
            curl_easy_setopt(easy, CURLOPT_URL, "https://domisc-01.server.tvdw.eu");
            curl_easy_setopt(easy, CURLOPT_VERBOSE, 1L);
            curl_easy_setopt(easy, CURLOPT_WRITEFUNCTION, write_cb);
            curl_easy_setopt(easy, CURLOPT_TIMEOUT, 5);
            curl_easy_setopt(easy, CURLOPT_PIPEWAIT, 1L);
            curl_easy_setopt(easy, CURLOPT_POSTFIELDS, "");
            curl_easy_setopt(easy, CURLOPT_POSTFIELDSIZE, 0);

            curl_multi_add_handle(multi, easy);
        }

        if (tv.tv_sec == 0 && tv.tv_usec == 0) {
            curl_multi_socket_action(multi, CURL_SOCKET_TIMEOUT, 0, &running);
        }

        fd_set crfds = rfds;
        fd_set cwfds = wfds;

        int count = select(maxfd+1, &crfds, &cwfds, NULL, &tv);
        if (!count) {
            curl_multi_socket_action(multi, CURL_SOCKET_TIMEOUT, 0, &running);
        }

        for (i = 0; i <= maxfd; i++) {
            if (FD_ISSET(i, &crfds)) {
                curl_multi_socket_action(multi, i, CURL_CSELECT_IN, &running);
            }
            if (FD_ISSET(i, &cwfds)) {
                curl_multi_socket_action(multi, i, CURL_CSELECT_OUT, &running);
            }
        }

        while (1) {
            int msgq;
            struct CURLMsg *msg = curl_multi_info_read(multi, &msgq);
            if (msg && (msg->msg == CURLMSG_DONE)) {
                CURL *easy = msg->easy_handle;
                fprintf(stderr, "Client %p ended, code: %d\n", easy, msg->data.result);
                if (msg->data.result != CURLE_OK) {
                    return 1;
                }
                curl_multi_remove_handle(multi, easy);
                curl_easy_cleanup(easy);
            }
            if (!msg) {
                break;
            }
        }
    }

    return 0;
}