Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!uwmcsd1!leah!itsgw!imagine!rpics!hiebeler
From: hiebeler@rpics (Dave Hiebeler)
Newsgroups: comp.unix.questions
Subject: Re: Debugging programs with fork
Message-ID: <1303@imagine.PAWL.RPI.EDU>
Date: 3 Oct 88 12:58:38 GMT
References: <12523@oberon.USC.EDU> <13819@mimsy.UUCP>
Sender: news@imagine.PAWL.RPI.EDU
Reply-To: hiebeler@turing.cs.rpi.edu (Dave Hiebeler)
Organization: RPI CS Dept.
Lines: 29

In article <13819@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes:
>In article <12523@oberon.USC.EDU> pgarg@pollux.usc.edu (Pankaj K. Garg) writes:
>> I am having trouble debugging programs which fork other
>>processes. Dbx doesn't seem to handle them easily.
>> I am using sun workstations...
>
>
>You are quite right; the existing Unix debuggers cannot handle programs
>that fork.  SunOS 4.0 provides new facilities that make it possible,
>but if you are dealing with older Unixes, you must either delete the
>fork, or fall back on more `traditional' debugging schemes.
>-- 

     I am curious, what facilities are in 4.0 that help you debug (dbx)
forking processes?  I haven't seen anything about that, and am quite
interested; just a pointer to where I can find info would be nice.

     Occasionally, when I just HAD to dbx something that was forking, I
would move it over to our Sequent Balance, which has a parallel version
of dbx.  I'd change the fork() to m_fork(), so the forked child would
run on a different processor, and then the "pdbx" as it's called allows
you to go to different processors and debug what's running on any given
one.  Sometimes that's infeasible, however, and of course not everyone
has a Balance either.
----
Dave Hiebeler      Internet: hiebeler@cs.rpi.edu  (preferred address)
R.D. Box 225A                userfrzk%mts@itsgw.rpi.edu
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  "xue zai xao"