Newsgroups: comp.sys.transputer
From: des@pact.srf.ac.uk (David Shepherd)
Subject: Re: Scheduling list...
Organization: University of Bristol, England
Date: Thu, 11 Aug 1994 12:41:37 GMT
Message-ID: <CuDF9D.3q5@info.bris.ac.uk>

Tomas Uhlin (tomas@marilyn.bion.kth.se) wrote:
: I'm writing a piece of time critical code for a T222. One thing
: that I would like to do is for a process to be able to see if
: there are other processes waiting to be executed on the scheduling
: list.  In the literature this is referred to as the "FRONT POINTER",
: but I haven't been able to find out how to get access to it.

: What I'm looking for is the opposite of the "STHF" instruction.

: Can anyone help me?

Try looking up the SAVEH instruction ... it saves the hi-pri
front and back pointers to Areg, Areg+1. Similarily SAVEL

: PS.  If somebody can tell me something about exactly when processes
: are moved from the "time waiting queue" to the list of processes to
: be executed, that would also be very helpful.

As soon as the process becomes ready -- i.e. the time is after the
time waited for -- and it reaches an interruptable point at the
same or lower priority (i.e. an entry will not come off the
low pri timer queue while the machine is executing at high pri)

--
David Shepherd,  INMOS ltd, 1000 Aztec West, Almondsbury, Bristol BS12 4SQ
email:	des@inmos.co.uk
tel:	+44 (0)454 611 638
[n.b. this message from account at SRF/PACT - please email to inmos.co.uk]

