Re: [libvirt] Re: [PATCH 2/3] Introduce monitor 'wait' command
On 04/08/09 19:44, Anthony Liguori wrote:
We want to be robust even in the face of poorly written management
apps/scripts so we need some expiration function too.
Well, if you want protect against broken apps, then yes, you'll have to
expire events ...
There two issues with this syntax. The first is that 'notify
EVENT'
logically acts on the global event set. That's not necessarily what you
want.
OK, having per-monitor events certainly makes sense.
The second issue is that there is no clear way to deliminate events
other than a new line. If we wanted to send data along with events, we
really want to be able to span multiple lines. Especially if we want
that data to be in the same format as some of the existing monitor
commands. You could get around this by introducing a new deliminator
like '.' but everyone can already handle '(qemu)'.
Point.
Also, I think where the above really shines is if you're a human
user
and you want to see all the events while debugging. You really don't
want to keep typing wait in the monitor.
So as a compromise, I think we need to introduce a mode where we can
do
the above but I'd like to wait until after the first round of these go
in. I'm thinking along the lines of 'wait N' where N can be -1 to
signify an unlimited number of events or something like that.
Hmm. Why would you want to use -- say -- "wait 3" ? It probably will
be either "loop forever" or "single event" mode in practice. We might
also have a "single event, but don't block if there isn't any" mode.
cheers,
Gerd