| Title: | DECnet/OSI for {ULTRIX,OSF/1} |
| Notice: | Indicate version and platform when writing...see #2 for kits |
| Moderator: | BULEAN::CARR |
| Created: | Wed Sep 25 1991 |
| Last Modified: | Thu Jun 05 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 2187 |
| Total number of notes: | 10469 |
{cross posted in CMA, DNU_OSI and DIGITAL_UNIX conf.}
I'm using select and xti osi with threads.
I've realised that I've a problem starting from OSF32
and DNA32. All was fine with OSF30 DNA30.
When I issue more than one t_snd in a very short time from a thread
and I wait for events (answers) coming from the network
with a select call in another thread, I observe that the
select only gets the first 2 or 3 events in an acceptable
time, then select fires with an event only at a distance
of some (3 or 4) seconds.
I've done a decnet osi thace with ctf and I see the delays.
select is called with a timeout of 1 second.
xti calls are wrapped.
I've tried to put pthread_lock_global_np and a pthread_unlock_global_np
around select and I get good response times, that is select doesn't
complete many times with timeout before getting the event.
If I do all in a syncronous way it's fine even without select wrap.
I know I have a work around that would be to decrease the timeout,
wrap select and may be call pthread_delay_np or/and pthread_yeld to allow
other threads to take the control but I would prefer to understand
if there is a problem somewhere.
With OSF40 (plus an xti patch sharable I've got for a t_look problem)
the behaviour is even worst in the sense that select doesn't fire
anymore even if there are some data that should still come in.
I've the problem with OSF32C too.
I've the problem with DNA32A too.
I haven't installed yet DNA32B MUP, I've only read the release
notes and they don't seem to mention anything about a problem like the
above. Anyway the installation of DNA32B is my next step.
Thanks for any advice
ABiotti Basestar Open group
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 2132.1 | UPSAR::WALLACE | Digital: A Dilbertian Company | Mon Feb 17 1997 18:09 | 13 | |
I don't think anything in DECnet 3.2B will help with this, but
it doesn't hurt to run the latest fixes.
Let me see if I understand you correctly - based on a ctf
trace you see a message recieved that should cause select
to complete, but it doesn't, at least not for 3 or 4
seconds. Is that correct?
My guess is it's not DECnet. Would it be possible to try
your program over TCP/IP?
Vince
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| 2132.2 | more | VARESE::BIOTTI | Tue Feb 18 1997 06:32 | 22 | |
> Let me see if I understand you correctly - based on a ctf
> trace you see a message recieved that should cause select
> to complete, but it doesn't, at least not for 3 or 4
> seconds. Is that correct?
No. When I see the message coming from the decnet trace, select
fires at the same time. The problem is that the response message
comes late even according to the decnet osi trace.
> My guess is it's not DECnet. Would it be possible to try
> your program over TCP/IP?
I'm running with a device (PLC). I should develop a server application
TCP based to do this. I see what I can do.
I've already verified that the problem is not in my physical device
since OSF30 works fine.
I'm wondering if the interaction of select with thread could be the
origin of the problem.
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| 2132.3 | UPSAR::WALLACE | Digital: A Dilbertian Company | Tue Feb 18 1997 18:28 | 11 | |
I'm still confused. You're doing a select for read, and as soon
as a message is received, the select fires? So what's the problem?
I can see two other possibilies. Either the local node is delaying
sending the initial "request" packet (or whatever you call the
action that generates a response from the remote node); or else
the remote node is taking a long time to generate a response.
Maybe you could type in a time-line of what the events are.
Vince
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| 2132.4 | close | VARESE::BIOTTI | Thu Feb 20 1997 14:02 | 9 | |
After a study of other decnet traces I've understood
my problem that's due to a limitation on my device and
not to a decnet problem. The different behaviour between
3.0 and 3.2 of OSF1 made me thinking to a bug somewhere
in 3.2 but that's not the case.
Thanks
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