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 */
{
  fprintf(stderr, "SET TIMEOUT to %ld\n", timeout_ms);
  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 = 1;
  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 = 10000;

  while (remaining >= 0) {
    int i;
    for (i = 0; i < 100; i++) {
      remaining--;
      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_multi_add_handle(multi, easy);
    }

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

    running = 1;

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

      fd_set crfds = rfds;
      fd_set cwfds = wfds;
      int now = 0;

      if(!tv.tv_sec && !tv.tv_usec) {
        now = 1;
        fprintf(stderr, "=== run now!\n");
      }

      for (i = 0; i <= maxfd; i++) {
        if (FD_ISSET(i, &crfds) ||
            FD_ISSET(i, &cwfds)) {
          fprintf(stderr, "select() on socket %d\n", i);
        }
      }

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

      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);
        }
      }

      if(now && !tv.tv_sec && !tv.tv_usec) {
        fprintf(stderr, "=== still NOW?\n");
        usleep(100000);
      }

      end:
      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;
}