Re: File monitor rewrite: Solaris (and other) help wanted

[Alexander Larsson <alexl redhat com>]

On Thu, 2015-01-15 at 10:49 -0500, Morten Welinder wrote:
> > My plan is to make it a guarantee of the API that both CREATED
> > and CHANGED events will always be followed by a CHANGES_DONE
> > hint.
>
> Great plan, but you cannot get that in a meaningful way.  Think
>
>     creat
>     write
>     mmap
>     close
>     # Further writes by way of the mapped region
>
> I don't think you can detect the end of that write.

You can always queue a timeout-based changes_done. There is no guarantee
that it will be after the "last ever" change. But you can still give a
guarantee that every change will always be followed by at least one
changes_done.

Its a good thing in general to do these virtual change_done anyway, as
it then automatically handles the logfile case where a file is written
to now and then but never closed.