Hi,
I'd like to ask how other people use c-ares with respect to handling
timeouts.
In general, we would like to tell c-ares "resolve foo.bar and if it
takes more than N seconds, just cancel the request".
Since there is no explicit API to cancel a particular request on-demand
(from our event loop, perhaps), we rely on calling "ares_process_fd(channel,
ARES_SOCKET_BAD, ARES_SOCKET_BAD)" every N seconds, where N is the
value of ARES_OPT_TIMEOUT.
However, this means we need to count the nameservers every time
/etc/resolv.conf is updated (might happen esp. in case of a roaming
laptop) and adjust the ARES_OPT_TIMEOUT value apropriately.
The other way might be to have a single channel per request but that
carries overhead as well..
How are others solving the issue?
Thank you,
Jakub
Received on 2011-08-10