[libvirt] [PATCH] add handling EINTR to test example of event loop
Daniel P. Berrange
berrange at redhat.com
Tue Jun 19 09:27:35 UTC 2012
On Mon, Jun 18, 2012 at 10:17:53PM +0300, Dan Kenigsberg wrote:
> On Mon, Jun 18, 2012 at 10:56:26AM +0100, Daniel P. Berrange wrote:
> > On Mon, Jun 18, 2012 at 05:43:55PM +0800, lvroyce at linux.vnet.ibm.com wrote:
> > > From: lvroyce <lvroyce at linux.vnet.ibm.com>
> > >
> > > some system call and signal will interrupt poll,
> > > making event loop stops and fails to react events and keepalive message
> > > from libvirt.
> > > adding handling EINTR to poll to make it more robust
> > >
> > > Signed-off-by: lvroyce <lvroyce at linux.vnet.ibm.com>
> > > ---
> > > examples/domain-events/events-python/event-test.py | 8 +++++++-
> > > 1 files changed, 7 insertions(+), 1 deletions(-)
> > >
> > > diff --git a/examples/domain-events/events-python/event-test.py b/examples/domain-events/events-python/event-test.py
> > > index 96dc268..b446c21 100644
> > > --- a/examples/domain-events/events-python/event-test.py
> > > +++ b/examples/domain-events/events-python/event-test.py
> > > @@ -188,7 +188,13 @@ class virEventLoopPure:
> > > sleep = (next - now) / 1000.0
> > >
> > > debug("Poll with a sleep of %d" % sleep)
> > > - events = self.poll.poll(sleep)
> > > + try:
> > > + events = self.poll.poll(sleep)
> > > + except select.error, e:
> > > + self.runningPoll = False
> > > + if not e.errno in (errno.EINTR, errno.EAGAIN):
> > > + raise
> > > + return
> >
> > It isn't possible for poll() to return EAGAIN according to the
> > manpage.
> >
> > If you remove that errno, then the patch would be ok. Also the
> > indentation in the except: block is too deep - line it up with
> > the try: block
>
> The same function has another possible exception-raiser: os.read() few
> lines below, and probably others. How about putting
>
> self.runningPoll = False
>
> in a "finally" clause opened right after the first self.runningPoll
> assignment?
Sounds like a reasonable idea.
Daniel
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