From: "EDWARD CRAGG" <ecragg@gmuvax.gmu.edu>
Subject: Re: Ada and Unix--Blocked Tasks
Date: 5 Aug 91 14:04:00 EST [thread overview]
Message-ID: <9108051811.AA04163@ajpo.sei.cmu.edu> (raw)
>
> From:cis.ohio-state.edu!zaphod.mps.ohio-state.edu!sdd.hp.com!spool.mu.edu!cs.
umn.edu!sctc.com!stachour@ucbvax.Berkeley.EDU
> (Paul Stachour)
> Subject: Re: Ada and Unix--Blocked Tasks
> Message-ID: <1991Aug2.181729.28061@sctc.com>
>
[stuff deleted]
>
> The methods indicated here seem kind-of wierd to me. After all,
> an Ada task is SUPPOSED to be an independent thread-of-control.
> And when I do something in Ada, I expect the run-time to arange to leave
> my other tasks alone, and only block the one needing the service.
>
[stuff deleted]
>
> Which leads us to the basic question:
>
> If the Ada system you are using can't do tasking "correctly"
> (i.e., in a non-blocking way) in its implementation, what is in
> error?
>
> Is it the OS (unix in this case)?
> Your Ada compiler vendor (Don't know who)?
> Your Ada run-time vendor?
> Or something else?
>
> Yours, ...Paul
>
Paul,
The factor which you are leaving out of your analysis is
that Ada was designed for Embedded Systems using specialized
computers (the ones I am most familiar with are the Navy's UYK-43 and
UYK-44). On these systems Ada tasking works "correctly" and is
reasonably portable between systems. The reason this that the Ada
run-time *IS* the machine's OS. (That incidently is one of the
reasons that the ALS/N seems so expensive, in addition to developing
an Ada compiler, etc, They also must develop two fourth generation
operating systems which will run on second generation architectures :-(
On all other systems with which I am familiar you end up in a finger
pointing exercise between the OS and the Ada Runtime and the blame
gets spread around.
ed
............................................................
Edward E Cragg Bitnet: ECRAGG@GMUVAX
Internet: ECRAGG@GMUVAX.GMU.EDU
next reply other threads:[~1991-08-05 19:04 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
1991-08-05 19:04 EDWARD CRAGG [this message]
-- strict thread matches above, loose matches on Subject: below --
1991-08-16 15:43 Ada and Unix--Blocked Tasks bu.edu!inmet!offer
1991-08-14 15:24 torolab4.vnet.ibm.com!jrussell
1991-08-10 4:59 Robert I. Eachus
1991-08-07 1:35 Bob Kitzberger @midnight
1991-08-06 20:12 mcsun!corton!chorus!nocturne.chorus.fr!jloup
1991-08-06 18:48 Mike Murphy
1991-08-06 17:23 David Emery
1991-08-06 14:57 Drew Johnson
1991-08-06 14:32 Dan L. Pierson
1991-08-06 14:17 mcsun!corton!chorus!nocturne.chorus.fr!jloup
1991-08-06 12:32 Arthur Evans
1991-08-06 9:17 Jim Showalter
1991-08-06 4:05 Mike Feldman
1991-08-05 19:56 Howard E. Turner, Jr.
1991-08-05 16:06 David Emery
1991-08-05 15:25 Fred Stluka
1991-08-05 14:14 Paul Stachour
1991-08-05 5:08 cis.ohio-state.edu!zaphod.mps.ohio-state.edu!sdd.hp.com!news.cs.indiana.e
1991-08-02 18:17 cis.ohio-state.edu!zaphod.mps.ohio-state.edu!sdd.hp.com!spool.mu.edu!cs.u
1991-08-02 13:28 Dennis Doubleday
1991-07-30 19:35 Dave Lewicki
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox