Path: utzoo!attcan!uunet!husc6!ukma!sean
From: sean@ms.uky.edu (Sean Casey)
Newsgroups: comp.unix.wizards
Subject: Will 4.2 select() catch OOB socket messages?
Message-ID: <9646@g.ms.uky.edu>
Date: 13 Jun 88 03:10:19 GMT
Organization: The Leaning Tower of Patterson Office @ The Univ. of KY
Lines: 28

I'm writing a real-time game program where a server multiplexes input
from a number of clients. Most of it works pretty well (thanks matt@oddjob),
but I can't seem to pick up Out Of Band messages with select().

I'm calling select() with a read fdset and an exception fdset.  The time
value is infinite (NULL).  When data comes in, the select returns and all is
well, but if a client sends an OOB, the select does not return as it should.
In other words, it seems to be ignoring OOB messages. According to all the
documentation I can find, the only exceptional condition for sockets is out
of band transmissions, and therefore I assume that if all is well, an OOB
sent will cause the select to return.

Did I assume wrong? I can code around it, but OOB messages seem to be an
ideal way of sending a "flush input buffer" command. Perhaps there's
something I need to be doing.

I did try setting the process group and trapping SIGURG, and sure enough,
the OOB messages are getting there. I just can't make select recognise
them.

Anyone know what I might be doing wrong?

Sean
-- 
***  Sean Casey                        sean@ms.uky.edu,  sean@ukma.bitnet
***  The Empire Defenestrator          {rutgers,uunet}!ukma!sean
***  ``I'm not gonna mail it, YOU mail it. I'M not gonna mail it... Hey! Let's
***  send it to Rutgers! Yeah! They won't mail it. They return everything.''