From: Wei Liu <wei.liu2@citrix.com>
To: David Vrabel <david.vrabel@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>,
Sergei Lebedev <sergei.a.lebedev@gmail.com>,
xen-devel@lists.xen.org
Subject: Re: [BUG] xs.watch and xs.unwatch are unreliable
Date: Thu, 3 Mar 2016 17:02:28 +0000 [thread overview]
Message-ID: <20160303170228.GA8132@citrix.com> (raw)
In-Reply-To: <56D86A90.9080002@citrix.com>
On Thu, Mar 03, 2016 at 04:47:12PM +0000, David Vrabel wrote:
> On 01/03/16 20:17, Sergei Lebedev wrote:
> > Hi list,
> >
> > I’ve initially wanted to report another inconsistency in
> > ``xen.lowlevel.xs`` documentation, but this time the issue is more
> > subtle.
>
> [...]
>
> > Here’s another example with a string token
> >
> > >>> token1 = str(100000000000000000000000000000)
> > >>> token2 = str(100000000000000000000000000000)
> > >>> token1 == token2
> > True
> > >>> h.watch("@introduceDomain", token1)
> > >>> h.unwatch("@introduceDomain", token2)
> > Traceback (most recent call last):
> > File "<stdin>", line 1, in <module>
> > xen.lowlevel.xs.Error: (2, 'No such file or directory’)
> >
> > I’m not sure what would be the best way to handle this as there might
> > be existing code relying on this undocumented behaviour. What do you
> > think?
>
> I think you're stuck with this behaviour. If you fix it there's a risk
> of breaking existing applications by unwatch removing the wrong watch.
>
I'm not sure I follow this. Do you have an example why it would remove
the wrong watch?
Wei.
> Perhaps you could extend the watch API to return a watch object that has
> an unwatch() method?
>
> watch = h.watch("/some/path", "token")
> ...
> watch.unwatch()
>
> David
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
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next prev parent reply other threads:[~2016-03-03 17:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-01 20:17 [BUG] xs.watch and xs.unwatch are unreliable Sergei Lebedev
2016-03-02 16:03 ` Wei Liu
2016-03-03 16:47 ` David Vrabel
2016-03-03 17:02 ` Wei Liu [this message]
2016-03-03 17:18 ` David Vrabel
2016-03-03 18:57 ` Wei Liu
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