curl / libcurl / API / curl_multi_setopt / CURLMOPT_TIMERDATA

CURLMOPT_TIMERDATA explained

Name

CURLMOPT_TIMERDATA - custom pointer to pass to timer callback

Synopsis

#include <curl/curl.h>
 
CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_TIMERDATA, void *pointer);

Description

A data pointer to pass to the timer callback set with the CURLMOPT_TIMERFUNCTION option.

This pointer is not touched by libcurl but is only be passed in to the timer callback's clientp argument.

Default

NULL

Protocols

This functionality affects all supported protocols

Example

struct priv {
  void *custom;
};
 
static int timerfunc(CURLM *multi, long timeout_ms, void *clientp)
{
 struct priv *mydata = clientp;
 printf("our ptr: %p\n", mydata->custom);
 
 if(timeout_ms) {
   /* this is the new single timeout to wait for */
 }
 else {
   /* delete the timeout, nothing to wait for now */
 }
}
 
int main(void)
{
  struct priv mydata;
  CURLM *multi = curl_multi_init();
  curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, timerfunc);
  curl_multi_setopt(multi, CURLMOPT_TIMERDATA, &mydata);
}

Availability

Added in curl 7.16.0

Return value

curl_multi_setopt returns a CURLMcode indicating success or error.

CURLM_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors.