Re: Cancelling asynchronous operations in libxl

[Euan Harris <euan.harris@citrix.com>]

Hi,

On Mon, Feb 02, 2015 at 05:43:58PM +0000, Ian Jackson wrote:
> Ian Jackson writes ("Re: Cancelling asynchronous operations in libxl"):
> > Euan Harris writes ("Re: Cancelling asynchronous operations in libxl"):
> > > The API you propose for libxl_ao_cancel, as described in the comment in
> > > libxl.h, looks reasonable to us.    The comment for ERROR_NOTIMPLEMENTED
> > > is a bit confusing: under what circumstances might a task actually be
> > > cancelled although libxl_ao_cancel returned ERROR_NOTIMPLEMENTED?
> > 
> > A single operation may go through phases during which cancellation is
> > effective, and phases during which it is not very effective because it
> > hasn't been properly hooked up.  [etc.]
> 
> Does that explanation answer your questions ?  What did you think of
> my alternative suggestions ?

Sorry, I didn't think you were waiting for a reply.   Your explanation
does answer my questions, thanks.

I think that the current proposed behaviour will suit us fine.   We will
probably treat the OK and NOTIMPLEMENTED cases in the same way, by using
more drastic means to stop the activity if cancellation is not confirmed
within a reasonable timeout.

Thanks,
Euan