Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 13 Mar 2001 20:56:32 -0500 (EST)
From:      Garrett Wollman <wollman@khavrinen.lcs.mit.edu>
To:        Lars Eggert <larse@ISI.EDU>
Cc:        net@FreeBSD.ORG
Subject:   Changing UDP select() behavior
Message-ID:  <200103140156.UAA42646@khavrinen.lcs.mit.edu>
In-Reply-To: <3AAEBEAE.F823CB8E@isi.edu>
References:  <3AAEBEAE.F823CB8E@isi.edu>

next in thread | previous in thread | raw e-mail | index | archive | help
<<On Tue, 13 Mar 2001 16:43:26 -0800, Lars Eggert <larse@ISI.EDU> said:

> I'm considering changing this, so that a select-to-write on a UDP socket
> will block until queue space becomes available.

Impossible.  The only way to find out whether a packet (or set of
packets, or a fragment of a packet) would be successfully enqueued is
to try it.  Even then there's no guarantee that it will get sent.

(Actually, ``impossible'' is too strong -- we could restructure the
entire network stack to make it possible to speculatively send packets
just to support this change in select() semantics.  It's merely
impractical.)

-GAWollman


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-net" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200103140156.UAA42646>