Cancel libcurl easy handle

Question

Is there an easy way to cancel a curl_easy_perform from another thread?

Answer 1

You have to use the callback functions (write/read/progress) to perform the cancel. The other thread needs to set a flag and the callback function checks the flag and returns the proper value to cancel the operation.

Answer 2

Im using progress callback atm. So if i return !0 in that it will cancel it?

Edit: Works a treat. Thanks!

Answer 3

The above strategy fails in some conditions. On some FTP sites I experience a 60 second delay before the transfer begins. During this time no callbacks are invoked, if my users try to cancel the transfer they get hung on the pthread_join until the transfer starts and the first callback runs.

Is my only options to do a pthread_cancel? Is there any other way to get curl_easy_perform to return?