Re: Sleep defunct

[Pavan Kumar Purohit]

Hello Bob,
thanks for the mail. I experiance the same problem in /bin/bash
The Shell code is very simple. I excute the program binary and sleep for
180 seconds in an infinate loop(while(1)).

Do you think that is is due to swap space (since there is no I/O request)
that the process is killed.
One observation I made is if I increase the sleep duration the program
runs for a longer time.

I am sort of newbee. and I am sorry if I am wasting your time.
Is there an alternate command for sleep in shell?.
thanks
regards
pavan


On Wed, 29 Jan 2003, Bob Proulx wrote:

> Pavan Kumar Purohit wrote:
> > I have used 'sleep' in a C shell script. This script in turn executes a
> > program. sleep is used to give delay between execution of the program in
> > the script.
> > Every 2-3 hours the sleep becomes defunct (see below)
> > root    21624  0.0  0.0     0    0 pts/4    Z    01:02   0:00 [sleep 
> > <defunct>]
> > root    21623  0.0  0.0  1308    4 pts/4    T    01:02   0:00 sleep 180
> > 
> > As a result the program is not executed.
> > Do u suggest anything.
> 
> Defunct processes are processes whose parent has not waited on them.
> They are dead.  But they have not gone away.  They are called zombies.
> The sleep program slept, then exited.  But the parent script has a
> problem and is not cleaning up after its children.
> 
> The system needs to transfer the return code from the child process to
> the parent.  Until the parent asks for the return code the system
> cannot release the process slot used by the defunct process.  If the
> parent exits then all children of that process will be inherited by
> the init process, pid #1.  One of the jobs of the init process is to
> clean up after these children.
> 
> Since your process has become defunct that means the script that ran
> it has a problem and not sleep.  Look at the 'ps -efH | less' listing
> and see the parent process.  Inspect the script around it and see what
> is happening there.  If you kill the parent process the defunct
> children will be cleaned up by init.
> 
> Also, you mentioned that you were using csh.  That program is not
> considered very robust for scripts.  Without even looking I feel
> certain the problem is in your /bin/csh binary.  Consider programming
> in /bin/sh instead.
> 
> Bob
>