From: ahoward <ahoward@...>
Date: 2002-12-10T08:23:04+09:00
Subject: Re: Ruby BUG when using PStore and fork

On Tue, 10 Dec 2002, Yukihiro Matsumoto wrote:

>
> In message "Ruby BUG when using PStore and fork"
>     on 02/12/10, Jeremy Henty <jeremy@chaos.org.uk> writes:
>
> |PStore does not appear to play well with fork.  This script
> |
> |#!/usr/bin/env ruby
> |
> |require 'pstore'
> |store = PStore.new("/tmp/pstore")
> |store.transaction do
> |  fork do
> |    store.abort
> |  end
> |  Process.wait
> |  exit
> |end
> |
> | ... results in:
> |
> |../pstore_fork_bug.rb:7: [BUG] Unknown longjmp status 7
> |ruby 1.6.7 (2002-03-01) [i586-linux]
>
> Ah, you can't.  "fork" creates copy of the process.  Copied child
> process cannot affect the parent process.  How can we abort
> transaction from the child process.
>
> Current pstore does not work well with threads either.

i have gotten around this problem by spawning another process using the unix
at command with a  time of 'now'

in otherwords, instead of forking spawn a process which does the same thing to
the pstore *now*.  pstores do work transactionally between processes.
additionally, you may want to copy the 'being updated' pstore to a temnam'd
file so any update transaction will not block the original process.

-a

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