curl / libcurl / API / curl_share_setopt / CURLSHOPT_UNLOCKFUNC

CURLSHOPT_UNLOCKFUNC explained

Name

CURLSHOPT_UNLOCKFUNC - mutex unlock callback

Synopsis

#include <curl/curl.h>
 
void unlockcb(CURL *handle, curl_lock_data data, void *clientp);
 
CURLSHcode curl_share_setopt(CURLSH *share, CURLSHOPT_UNLOCKFUNC, unlockcb);

Description

Set a mutex unlock callback for the share object. There is a corresponding CURLSHOPT_LOCKFUNC callback called when the mutex is first locked.

The unlockcb argument must be a pointer to a function matching the prototype shown above. The arguments to the callback are:

handle is the currently active easy handle in use when the share object is released.

The data argument tells what kind of data libcurl wants to unlock. Make sure that the callback uses a different lock for each kind of data.

clientp is the private pointer you set with CURLSHOPT_USERDATA. This pointer is not used by libcurl itself.

Protocols

This functionality affects all supported protocols

Example

extern void mutex_unlock(CURL *, curl_lock_data, void *);
 
int main(void)
{
  CURLSHcode sh;
  CURLSH *share = curl_share_init();
  sh = curl_share_setopt(share, CURLSHOPT_UNLOCKFUNC, mutex_unlock);
  if(sh)
    printf("Error: %s\n", curl_share_strerror(sh));
}

Availability

Added in curl 7.10.3

Return value

CURLSHE_OK (zero) means that the option was set properly, non-zero means an error occurred. See libcurl-errors for the full list with descriptions.