On Mon, May 18, 2009 at 01:54:28PM +0100, Daniel P. Berrange wrote:
> On Mon, May 18, 2009 at 01:25:35PM +0100, Daniel P. Berrange wrote:
> > On Thu, May 14, 2009 at 06:43:10PM -0700, Noah Zoschke wrote:
> > > Hello,
> > >
> > > I have been playing around with the libvirt domain event handlers in
> > > Python and am seeing something surprising. I am using trunk libvirt
> > > and `event-test.py` with some more of the debugging strings uncommented.
> > >
> > > When I trigger my first event:
> >
> > [snip]
> >
> > > So my handler is always one event behind.
> > >
> > > This behavior is not intended is it? Am I missing either something in
> > > `event-test.py` or in how I am using virsh that would correct this
> > > behavior?
> >
> > This is not intended behaviour. I have verified that I see the same
> > problem when running the event-test.py demo program. The C based
> > example event-test.c does work correctly. So either this is a bug
> > in the python demo program, or a bug in the python APIs for events.
> > Not sure which yet...
>
> The demo program is horribly broken wrt handling timeouts
>
> Also the python binding was not incrementing the ref count on
> the domain objects it was wrapping.
>
> Daniel
>
> diff -r 08f3de2814fb examples/domain-events/events-python/event-test.py
> --- a/examples/domain-events/events-python/event-test.py Mon May 18 13:15:33 2009 +0100
> +++ b/examples/domain-events/events-python/event-test.py Mon May 18 13:53:59 2009 +0100
> @@ -6,6 +6,8 @@ import select
> mypoll = select.poll()
> TIMEOUT_MS = 1000
>
> +debug = False
> +
> # handle globals
> h_fd = 0
> h_events = 0
> @@ -66,8 +68,9 @@ def myPollEventToEventHandleType(events)
> return ret;
>
> def myAddHandle(fd, events, cb, opaque):
> - global h_fd, h_events, h_cb, h_opaque
> - #print "Adding Handle %s %s %s %s" % (str(fd), str(events), str(cb), str(opaque))
> + global h_fd, h_events, h_cb, h_opaque, debug
> + if debug:
> + print "Adding Handle %s %s %s %s" % (str(fd), str(events), str(cb), str(opaque))
> h_fd = fd
> h_events = events
> h_cb = cb
> @@ -76,36 +79,48 @@ def myAddHandle(fd, events, cb, opaque):
> return 0
>
> def myUpdateHandle(watch, event):
> - global h_fd, h_events
> - #print "Updating Handle %s %s" % (str(h_fd), str(event))
> + global h_fd, h_events, debug
> + if debug:
> + print "Updating Handle %s %s" % (str(h_fd), str(event))
> h_events = event
> mypoll.unregister(h_fd)
> mypoll.register(h_fd, myEventHandleTypeToPollEvent(event))
>
> def myRemoveHandle(watch):
> - global h_fd
> - #print "Removing Handle %s" % str(h_fd)
> + global h_fd, debug
> + if debug:
> + print "Removing Handle %s" % str(h_fd)
> mypoll.unregister(h_fd)
> h_fd = 0
> return h_opaque
>
> def myAddTimeout(timeout, cb, opaque):
> - global t_active, t_timeout, t_cb, t_opaque
> - #print "Adding Timeout %s %s %s" % (str(timeout), str(cb), str(opaque))
> - t_active = 1;
> + global t_active, t_timeout, t_cb, t_opaque, debug
> + if debug:
> + print "Adding Timeout %s %s %s" % (str(timeout), str(cb), str(opaque))
> + if timeout == -1:
> + t_active = 0
> + else:
> + t_active = 1
> t_timeout = timeout;
> t_cb = cb;
> t_opaque = opaque;
> return 0
>
> def myUpdateTimeout(timer, timeout):
> - global t_timeout
> - #print "Updating Timeout %s %s" % (str(timer), str(timeout))
> + global t_timeout, t_active, debug
> + if debug:
> + print "Updating Timeout %s %s" % (str(timer), str(timeout))
> + if timeout == -1:
> + t_active = 0
> + else:
> + t_active = 1
> t_timeout = timeout;
>
> def myRemoveTimeout(timer):
> - global t_active
> - #print "Removing Timeout %s" % str(timer)
> + global t_active, debug
> + if debug:
> + print "Removing Timeout %s" % str(timer)
> t_active = 0;
> return t_opaque
>
> @@ -159,6 +174,8 @@ def main():
>
> while 1:
> try:
> + if debug:
> + print "Poll sleep %d" % t_active
> sts = mypoll.poll(TIMEOUT_MS)
> except select.error, err:
> if err[0] == errno.EINTR:
> @@ -168,17 +185,19 @@ def main():
> print "Keyboard Interrupt caught - exiting cleanly"
> break
>
> + if t_cb and t_active == 1:
> + if debug:
> + print "Invoking Timeout CB"
> + t_cb(t_timeout, t_opaque[0], t_opaque[1])
> +
> if not sts:
> - #print "Timed out"
> + if debug:
> + print "Timed out"
> continue
>
> rfd = sts[0][0]
> revents = sts[0][1]
>
> - if t_active:
> - #print "Invoking Timeout CB"
> - t_cb(t_timeout, t_opaque[0], t_opaque[1])
> -
> if revents & select.POLLHUP:
> print "Reset by peer";
> return -1;
> diff -r 08f3de2814fb python/libvir.c
> --- a/python/libvir.c Mon May 18 13:15:33 2009 +0100
> +++ b/python/libvir.c Mon May 18 13:53:59 2009 +0100
> @@ -1653,6 +1653,7 @@ libvirt_virConnectDomainEventCallback(vi
> LIBVIRT_ENSURE_THREAD_STATE;
>
> /* Create a python instance of this virDomainPtr */
> + virDomainRef(dom);
> pyobj_dom = libvirt_virDomainPtrWrap(dom);
> pyobj_dom_args = PyTuple_New(2);
> if(PyTuple_SetItem(pyobj_dom_args, 0, pyobj_conn_inst)!=0) {
ACK, looks fine to me,
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel@xxxxxxxxxxxx | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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