| Value | Meaning |
|---|---|
| none | don't use |
| share | specify a data type to share |
| unshare | specify which data type to stop sharing |
| lockfunc | pass in a 'curl_lock_function' pointer |
| unlockfunc | pass in a 'curl_unlock_function' pointer |
| userdata | pass in a user data pointer used in the lock/unlock callback functions |
| last | never use |
pass in a user data pointer used in the lock/unlock callback functions