CURLSHOPT_UNLOCKFUNC(3) Library Functions Manual CURLSHOPT_UNLOCKFUNC(3)

CURLSHOPT_UNLOCKFUNC - mutex unlock callback

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

Set a mutex unlock callback for the share object. There is a corresponding CURLSHOPT_LOCKFUNC(3) 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(3). This pointer is not used by libcurl itself.

This functionality affects all supported protocols

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));
}

Added in curl 7.10.3

CURLSHE_OK (zero) means that the option was set properly, non-zero means an error occurred. See libcurl-errors(3) for the full list with descriptions.

CURLSHOPT_LOCKFUNC(3), curl_share_cleanup(3), curl_share_init(3), curl_share_setopt(3)

2024-09-18 libcurl