TIP #344: Bring TCP_NODELAY and SO_KEEPALIVE to socket options
_____________________________________________________________________________
TIP:	344
Title:	Bring TCP_NODELAY and SO_KEEPALIVE to socket options
Version:	$Revision: 1.2 $
Authors:	Alexandre Ferrieux <alexandre.ferrieux@gmail.com>
State:	Draft
Type:	Project
Tcl-Version:	8.7
Vote:	Pending
Created:	Wed Dec 31 00:00:00 UTC 2008
Abstract
Just expose to script level, via fconfigure, the two most important setsockopt() use cases: TCP_NODELAY (disabling the Nagle agorithm) and SO_KEEPALIVE (sending automatic keepalives).
Background & Rationale
Currently, there is no way to set nodefault values to a Tcl socket's underlying socket options TCP_NODELAY and SO_KEEPALIVE. That is frustrating because all TCP stacks support setsockopt().
Of these two options, the most important I guess is TCP_NODELAY. Indeed, the Nagle algorithm being on by default may introduce unwanted latencies in some specific cases. This TIP does not try to argument about the prevalence of these cases; the ubiquity of setsockopt(TCP_NODELAY) suffices to justify exposing it to script level.
Proposed Change
This TIP proposes to add two boolean [fconfigure] options to sockets: -nodelay (or -nonagle, or -nagle, take your pick) and -keepalive.
Reference Implementation
Pretty trivial; will be provided shortly after validation. The code has even been in place for a long time, though only in the Windows-specific part, and commented/ifdef'ed out...
Copyright
This document has been placed in the public domain.
_____________________________________________________________________________
Colophon
TIP AutoGenerator - written by Donal K. Fellows