[racket] tcp-read handlers

To supplement Matthew's response, see exn style: 

 http://plt.eecs.northwestern.edu/snapshots/current/doc/style/Choosing_the_Right_Construct.html#%28part._.Exceptions%29

This does not address the problem part. 

On Jan 18, 2014, at 11:04 AM, Matthew Flatt wrote:

> The `exn?` predicate would catch all exceptions from the base
> libraries.[*]
> 
> I think the problem may be that the underlying TCP port is read in a
> separate decoding thread, and so the exception and printing happens in
> that thread. If I'm right, then that seems like a flaw in our
> implementation of decoding.
> 
> [*] To avoid interfering with the `exn:break?` exceptions triggered by
>    Ctl-C, you almost always want `exn:fail?` instead of just `exn?`.
> 
> At Sat, 18 Jan 2014 09:50:15 -0200, Eduardo Bellani wrote:
>> -----BEGIN PGP SIGNED MESSAGE-----
>> Hash: SHA1
>> 
>> Is there a way to install a handler for the tcp-error exception?
>> I have a function like this
>> 
>> (define (get-page link-url (max-tries 5))
>>  (let loop ([current-try 0])
>>    (with-handlers ([exn?
>>                     (? (e)
>>                        (if (> current-try max-tries)
>>                            (error 'get-page
>>                                   "failed because it exceeded ~a tries"
>>                                   max-tries)
>>                            (begin (sleep 2)
>>                                   (loop (add1 current-try)))))])
>>      (get-pure-port link-url))))
>> 
>> that I'm using to crawl some data, but sometimes it's printing:
>> 
>> tcp-read: error reading
>>  system error: Connection reset by peer; errno=104
>>  context...:
>>   /usr/racket/collects/net/url.rkt:392:3
>> 
>> Thanks for the attention.
>> 
>> -----BEGIN PGP SIGNATURE-----
>> Version: GnuPG v1.4.14 (GNU/Linux)
>> Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/
>> 
>> iEYEARECAAYFAlLaanUACgkQSbLl0kCTjGkm+ACbBSMyUuY4NOYjdLMgba/OJAFc
>> 8OYAn0NkLMKLLma/MxAeEFMLtnrMekOY
>> =aAUJ
>> -----END PGP SIGNATURE-----
>> ____________________
>>  Racket Users list:
>>  http://lists.racket-lang.org/users
> ____________________
>  Racket Users list:
>  http://lists.racket-lang.org/users