crosstalk

crosstalk

Post by Adam Wasserm » Wed, 15 May 1996 04:00:00



Hello people.  I was just wondering if anyone out there has seen the same sort
of behavior with their sockets, or had any ideas where such behavior might
originate.

I've got a bunch of daemons that spawn workers, all of which communicate with
each other in various ways.  There are no superfluous connections, and
channels are closed and opened only when they are needed, with the exception
of those cases where keeping a permanent connection is desirable (ie -
between daemons, who want to be aware of who is alive and who isn't).  There
can be a lot of open channels at any instant, however - especially if the
load is particularly heavy.

Everything works fine except that once in a while, a message will arrive
on the wrong channel.  That is, if I send a message along channel A it
will for some reason arrive on channel B.  This is not a case of a mistaken
socket identity, because I've checked this.  Furthermore, this behavior can
only be observed rarely, and without the aid of logfiles would be virtually
impossible to detect at all.  When I say rarely I mean that most of the time
the message along channel A will end up at the other end of channel A; it's
only sometimes that it ends up in the wrong place, and not always the same
message.

Two of the daemons are running on UnixWare 2.01 and the other (of which there
are multiple copies) are running on Linux.  The behavior usually only
exhibits itself under a heavy load (ie, when there are many processes being
spawned and their connections made).  Originally, when I was dealing with
closing appropriate file descriptors just after forking a new process, I
was in the habit of dup'ing those of the parent that the child needed to keep
and then closing the original copy.  Seeing this behavior, I wasn't sure if
the dup was causing the crosstalk, so I stopped doing it.  I haven't seen
the behavior since, but it was rare anyway so I don't know if I've solved
anything.

Thanks.

 
 
 

1. Crosstalk (audio <-> video)

I've been noticing lately that when I've got X running and (for example)
scroll a window in Netscape (or any other window with a lot of contrast
such as text) I get a significant amount of crackle out of the speakers.

Sound card: Yamaha OPL3/SA-2 (latest OSS commercial driver)
Video Card: VideoLogic 600 (ET6000 4Mb) XFree 3.3.2 SVGA driver -- BTW
changing the resolution doesn't have any effect

Does anyone have any idea if this can be fixed, and how.

A search for linux & sound & crosstalk on AltaVista didn't reveal
anything useful.

Thanks in advance for any light shed on the issue.

--
James Tappin,             O__      "I forget the punishment for using

http://www.tappin.force9.co.uk/     with data loss in it I fancy"

2. kernel: down/up inside of lock_kernel/unlock_kernel?

3. xtalk or crosstalk

4. NFS mounting mail directories