Re: [Hardhats-members] Re: A troublesome and concerning error.....

[Bhaskar, KS]

Title: Re: [Hardhats-members] Re: A troublesome and concerning error.....

Actually just forking a process is not good enough because a forked process is part of the same process group, and can, for example receive unwanted signals.  In GT.M, a Job command causes a fork.  The child process forks to create a grand child.  The intermediate process then terminates so that the grand child is "adopted" by process 1 (init).  This isolates the Job'd process from the process executing the Job command.

Note that some (maybe even most?) zombie  processes (processes which can't be killed because they are already theoretically dead, but which won't go away) result from bugs in the operating system.  This is not just Linux/UNIX.  OpenVMS has them too.

-- Bhaskar

------Original Message------
From: Greg Woodhouse
To: hardhats-members@lists.sourceforge.net
ReplyTo: hardhats-members@lists.sourceforge.net
Sent: Nov 3, 2005 12:08 PM
Subject: Re: [Hardhats-members] Re: A troublesome and concerning error.....


On Nov 3, 2005, at 3:49 AM, Bhaskar, KS wrote:

> Greg --
>
> In GT.M, this would be the expected behavior.

That was actually the point.

> The JOB command forks a separate process that is completely 
> independent of the process that executes the JOB command (indeed, 
> the JOB'd process gets init as the parent process).  So, a kill -9 
> of the JOB'd process has no effect on the process executing the JOB 
> command.
>

Okay. If the process were simply forked off, then this wouldn't 
happen. But, as you know, an unwaited for child is a problem. (Come 
to think of it, I believe I saw a zombie in a process listing a 
couple of days ago. It might even have been Halloween.)

===
Gregory Woodhouse
[EMAIL PROTECTED]
"The finger pointing at the moon is
not the moon."
--Buddhist saying





-------------------------------------------------------
SF.Net email is sponsored by:
Tame your development challenges with Apache's Geronimo App Server. Download
it for free - -and be entered to win a 42" plasma tv or your very own
Sony(tm)PSP.  Click here to play: http://sourceforge.net/geronimo.php
_______________________________________________
Hardhats-members mailing list
Hardhats-members@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/hardhats-members


--------------------------
Sent from my BlackBerry Wireless Handheld