mojave man page for curlmopt_timerfunction

CURLMOPT_TIMERFUNCTION(3)				     curl_multi_setopt options					 CURLMOPT_TIMERFUNCTION(3)

NAME
       CURLMOPT_TIMERFUNCTION - set callback to receive timeout values

SYNOPSIS
       #include <curl/curl.h>

       int timer_callback(CURLM *multi,    /* multi handle */
			  long timeout_ms, /* see above */
			  void *userp);    /* private callback pointer */

       CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_TIMERFUNCTION, timer_callback);

DESCRIPTION
       Pass a pointer to your callback function, which should match the prototype shown above.

       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 interval of timeout_ms. Each time 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 means you should delete your timer.

       A timeout_ms value of 0 means you should call curl_multi_socket_action(3) or curl_multi_perform(3) (once) as soon as possible.

       timer_callback will only be called when the timeout_ms changes.

       The userp pointer is set with CURLMOPT_TIMERDATA(3).

       The timer callback should return 0 on success, and -1 on error. This callback can be used instead of, or in addition  to,  curl_multi_time-
       out(3).

DEFAULT
       NULL

PROTOCOLS
       All

EXAMPLE
       static gboolean timeout_cb(gpointer user_data) {
	   if (user_data) {
	       g_free(user_data);
	       curl_multi_setopt(curl_handle, CURLMOPT_TIMERDATA, NULL);
	   }
	   int running;
	   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);
	   }
	   curl_multi_setopt(multi, CURLMOPT_TIMERDATA, id);
	   return 0;
       }

       curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, timerfunc);

AVAILABILITY
       Added in 7.16.0

RETURN VALUE
       Returns CURLM_OK if the option is supported, and CURLM_UNKNOWN_OPTION if not.

SEE ALSO
       CURLMOPT_TIMERDATA(3), CURLMOPT_SOCKETFUNCTION(3),

libcurl 7.54.0							 February 03, 2016					 CURLMOPT_TIMERFUNCTION(3)