On Sun, 25 Mar 2012, Lijo Antony wrote:

> Here we can see that curl uses socket 6 for transfer, which is the external
> socket returned by the opensocket callback. But curl also creates another
> socket, socket 7 internally, and it is being used during the name lookup. I
> am not sure this is a dummy socket mentioned earlier but I believe this is
> the same behavior observed by Christian on windows as well.

Are you using a libcurl built with c-ares for name resolves?

> My issue with this extra socket is, since I don't open this socket, I cannot
> manage this socket using boost::asio library on windows.

Very true. libcurl does not guarantee that every socket it uses is created
with the callback. In the c-ares case, there's a fix to be made actually as
c-ares provides a callback of its own (with ares_set_socket_callback, added in
c-ares 1.6.0) so we can in fact fix this - assuming you are using c-ares here.

-- 
  / daniel.haxx.se
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