CURLSHOPT_UNLOCKFUNC - Man Page
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's 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. This pointer is not used by libcurl itself.
CURLSHcode sh; 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 7.10
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_setopt(3), curl_share_cleanup(3), curl_share_init(3)
curl_share_setopt(3), CURLSHOPT_LOCKFUNC(3), CURLSHOPT_USERDATA(3).