From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ewan Mellor Subject: Re: xenstore watches not firing for external-to-xend code using xen.xend.xenstore classes Date: Thu, 9 Feb 2006 08:55:42 -0800 Message-ID: <20060209165541.GA3151@localhost.localdomain> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Charles Duffy Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Thu, Feb 09, 2006 at 10:35:50AM -0600, Charles Duffy wrote: > I'm trying to write a simple xenstore-based watchdog, as discussed > previously on this list (quite some time ago -- it got pushed to the > back of my priority list for a bit). > > [Snip] > > > #!/usr/bin/env python > > from xen.xend.xenstore.xstransact import xstransact > from xen.xend.xenstore.xswatch import xswatch > > from pprint import pprint > import time, logging > logging.basicConfig(level=logging.DEBUG) > > TROOT = '/tool/watchdog' > > class XenWatchdog: > def __init__(self): > xswatch('@releaseDomain', self.callback, 'releaseDomain') > xswatch('@introduceDomain', self.callback, 'introduceDomain') > xswatch('%(TROOT)s/test' % locals(), self.callback, 'test') > def callback(self, *args, **kwargs): > pprint([ 'onReleaseDomain', args, kwargs ]) callback needs to return True to say that it would like to stay registered. As it is, you are returning nothing, which looks like False, which means your callback is deregistered after the first call. This changed a couple of months ago, and it still bites people. (My kingdom for a static type system ;-) Ewan.