"Daniel Stenberg" <daniel-curl_at_haxx.se> said:

> Yes we can. To make it really nice I guess we can make the code setup a
> listening udp socket (or PF_LOCAL?) on a random port number on localhost and
> then let the threaded resolver send a "beep" to it when its done. Then the
> select()ing in the app layer will work as expected as well.
>
> Curl_multi_ares_fdset() would need to be written to return the fd_set the app
> should select on.

I've patched hostip.c to use a dummy UDP socket (Windows doesn't have
PF_LOCAL). Only tested with libtests 503, 504, 507 and 509 which runs fine
now (they didn't before this patch).

Only problem seems that there is some sync/contention issue with using
stderr:

set CURL_TRACE=1
lib509.exe https://www.thawte.com/ucgi/browsercheck.exe
...
15351374: Winsock-error 0, addr : not yet
running=1 res=0
HANDLE 00CEB238: State: 2
1532: resolved okay, dn65.205.248.243
s 0xcec120
running=1 res=0

It's no difference removing fflush(stderr) in trace_it().

diff -u3 -w CVS-latest/lib/hostip.c lib/hostip.c attached
(note the '-w' option).

--gv