Mailing-List: contact modperl-help@perl.apache.org; run by ezmlm
Precedence: bulk
Received-SPF: neutral (athena.apache.org: 129.199.96.40 is neither permitted
 nor denied by domain of nicolas.george@normalesup.org)
Date: Thu, 12 Nov 2009 19:53:32 +0100
From: Nicolas George <nicolas.george@normalesup.org>
To: modperl@perl.apache.org
Subject: AJAX pseudo-push
Message-ID: <20091112185332.GC31986@phare.normalesup.org>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha1;
	protocol="application/pgp-signature"; boundary="bp/iNruPH9dso1Pn"
Content-Disposition: inline
User-Agent: Mutt/1.5.18 (2008-05-17)


--bp/iNruPH9dso1Pn
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Hi.

There is an increasingly popular technique to emulate server-initiated push
over HTTP. I'm sure everyone here knows it well, but for the sake of
completeness: the clients sends a XMLHttpRequest to the server in the
background; the server does not answer it immediately, but keeps it for
later when there is actually something to say to the client; if the request
timeouts, the client re-sends it.

I am wondering if this technique is usable with Apache in general and
mod_perl in particular.

The obvious solution is to have the request handler sleep until it has
something to answer does not work, since it requires a worker thread and a
perl interpreter for each waiting client, and perl interpreters are few and
expensive.

The ideal solution would be if some part of the request handler could put
the current request (A) "on hold". Later, the handler for another request
(B) could retrieve the request A and generate an answer for it, or at least
wake it up.

Is something like this possible with Apache and mod_perl?

Regards,

--=20
  Nicolas George

--bp/iNruPH9dso1Pn
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (GNU/Linux)

iEYEARECAAYFAkr8WawACgkQsGPZlzblTJMxIACfT7F0cNM3dZVFiOyzWN/yfjif
a/oAn1PpJv5wZ4Q9a9Rf1YYMlDPpwQkZ
=fli5
-----END PGP SIGNATURE-----

--bp/iNruPH9dso1Pn--