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From: paul@sequoia.cray.com (Paul Dow (CRI-UK))
Newsgroups: comp.unix.questions
Subject: Re: How can a child learn of its parents termination?
Message-ID: <020715.19092@timbuk.cray.com>
Date: 4 Apr 91 09:02:59 GMT
Article-I.D.: timbuk.020715.19092
References: <94559@lll-winken.LLNL.GOV>
Reply-To: paul@sequoia.cray.com (Paul Dow (CRI-UK))
Organization: Cray Research, Inc.
Lines: 21


In article <94559@lll-winken.LLNL.GOV>, booloo@lll-crg.llnl.gov (Mark Boolootian) writes:
|> The subject pretty much says it all:  Is it possible for a child to receive
|> notification of its parent's termination?  One possibility would be to check
|> the parent process id from time to time but this won't help me.  I have a
|> child sleeping on a semaphore, normally awakened by the parent.  If the parent
|> terminates, the child is going to sleep forever.  I need some way of waking
|> the child up upon parent's death so that the child may exit.
|> 

A couple of ideas might be:

1) Use the SEM_UNDO option for a semaphore - this can be used to adjust the value
   of a semaphore when a process exits.

2) Use a pipe between the parent & child process.  The child could then detect
   the loss of the pipe.

It sounds to me as if option 1) is what will provide what you're looking for.

Paul.