Re: [Qemu-block] [Qemu-devel] [RFC v4 18/21] blockjobs: add block-job-finalize

[Kevin Wolf]

Am 28.02.2018 um 20:14 hat John Snow geschrieben:
> 
> 
> On 02/28/2018 01:15 PM, Kevin Wolf wrote:
> > Is it because you want to avoid that the user picks an automatic job for
> > completing the mixed transaction?
> 
> I wanted to avoid the case that a job without the manual property would
> be stuck "pending" -- which I have defined to mean that it is waiting on
> an authorization from the user -- which isn't really true: it's waiting
> on its peers in the transaction to receive that authorization.
> 
> It would indeed be simpler to just let them stick around in PENDING like
> their peers, but it felt like a hacky way to allow mixed-mode
> transactions -- like they had been promoted for just a subset of their
> lifetime.
> 
> So, mostly it was a semantic decision and not a functional one based on
> what I considered "WAITING" to mean vs "PENDING".
> 
> If the definitions (and documentation) are adjusted it can be changed
> for the simpler layout if it seems just as good from the API
> perspective. (It's certainly better implementationally, as you say.)

I actually like it better conceptually, too, because I think of WAITING
as a state that waits for jobs in earlier states (i.e. RUNNING/READY
usually) and then everything moves forward together. Also waiting for
jobs that are already in a later state like PENDING, but only for
automatic jobs, makes the mental model more complex (or maybe it's just
me...).

Kevin