My apologies, it looks like it was a false alarm and the blocking
actually comes from PHP's session manager.


On 11 September 2012 14:22, a m <> wrote:
> Hi,
> I was using gethostbyname up until recently but switched to Net_DNS2
> due to lack of support for a timeout. Now I discovered some "worrying"
> behaviour and hope someone here get shed some light onto it.
> I am running PHP inside an Apache 2 installation as module and noticed
> that once I call gethostbyname it appears to block all other
> concurrent independent requests to PHP pages until the call returned.
> I do seem to remember that there were some reentrant issues with the
> native gethostbyname function but I wouldnt assume there is some kind
> of global lock on it blocking the entire runtime.
> What is even more worrying is that Net_DNS2 appears to show the same
> behaviour, even though from my understanding it is supposed to work
> completely independent with its own streams/sockets.
> Of course this behaviour only shows with a domain with non-responding
> name servers, hence I used You should be able to reproduce
> it easily with
> <?php
>         echo gethostbyname('');
>         // OR ......
>         require('Net/DNS2.php');
>         $dr=new Net_DNS2_Resolver(['nameservers'=>['']]);
>         $ans=$dr->query('');
>         echo $ans->answer[0]->address;
> ?>
> Could it have to do something with a configuration setting or might I
> be onto something?
> Thanks a lot!
> cheers,
> Alexander

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