NAME

SYNOPSIS

#include <curl/curl.h>
int timer_callback(CURLM *multi,    /* multi handle */
                   long timeout_ms, /* timeout in number of ms */
                   void *userp);    /* private callback pointer */
CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_TIMERFUNCTION, timer_callback);

DESCRIPTION

Certain features, such as timeouts and retries, require you to call libcurl even when there is no activity on the file descriptors.

Your callback function timer_callback should install a non-repeating timer with an expire time of timeout_ms milliseconds. When that timer fires, call either curl_multi_socket_action(3) or curl_multi_perform(3), depending on which interface you use.

A timeout_ms value of -1 passed to this callback means you should delete the timer. All other values are valid expire times in number of milliseconds.

The timer_callback will only be called when the timeout expire time is changed.

The userp pointer is set with CURLMOPT_TIMERDATA(3).

The timer callback should return 0 on success, and -1 on error. If this callback returns error, all transfers currently in progress in this multi handle will be aborted and fail.

This callback can be used instead of, or in addition to, curl_multi_timeout(3).

WARNING: do not call libcurl directly from within the callback itself when the timeout_ms value is zero, since it risks triggering an unpleasant recursive behavior that immediately calls another call to the callback with a zero timeout...

DEFAULT

PROTOCOLS

EXAMPLE

static gboolean timeout_cb(gpointer user_data)
{
  int running;
  if(user_data) {
    g_free(user_data);
    curl_multi_setopt(curl_handle, CURLMOPT_TIMERDATA, NULL);
  }
  curl_multi_socket_action(multi, CURL_SOCKET_TIMEOUT, 0, &running);
  return G_SOURCE_REMOVE;
}
static int timerfunc(CURLM *multi, long timeout_ms, void *userp)
{
  guint *id = userp;
  if(id)
    g_source_remove(*id);
  /* -1 means we should just delete our timer. */
  if(timeout_ms == -1) {
    g_free(id);
    id = NULL;
  }
  else {
    if(!id)
      id = g_new(guint, 1);
    *id = g_timeout_add(timeout_ms, timeout_cb, id);
  }
  current_timer = id;
  return 0;
}
curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, timerfunc);

AVAILABILITY

RETURN VALUE

SEE ALSO