On Tue, 26 Aug 2014, Kevin Day wrote:

> I just found what looks like the same issue in the PHP curl binding, except
> that it happens 100% of the time. On a FreeBSD 10.0 box, do:

Which libcurl version are you using for this? I don't have any FreeBSD machine
myself to try this on... Also, it is probably helpful for people here if you
can reproduce this with a plain C program to peel off a thick layer of
unknown.

> Which works fine. Then do the same thing using the multi interface, and it hangs:

libcurl itself has no internal difference between the easy and the multi
interface since a few years, it is all the single code path for stuff like
this which makes external differences between easy and multi quite
interesting!

> Tracing what¢s going on in the process shows that it makes a DNS request,
> gets a response, calls getsockname() on the addresses in the response, then
> hangs.

But if you can repeat the problem, can't you then attach a debugger and re-run
the case and single-step forward to see what it is doing when hanging like
that?

I assume this "hang" is then going on for a long time if you don't interrupt
it?

Another approach could be to try out Michael Wallner's pending work for the
threaded resolvers: https://github.com/bagder/curl/pulls

> Recompiling using c-ares instead of the default threaded resolver makes it
> work fine.

And what about if you use the stock synchronous resolver, does that show any
problems?

-- 
  / daniel.haxx.se

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Received on 2014-08-27