[Info-vax] CRTL and RMS vs SSIO

[Simon Clubley]

On 2021-10-07, Dave Froble <davef at tsoft-inc.com> wrote:
>
> Now I''m just a dumb polock, wandered down out of the woods.  But I just 
> don't see where upward compatibility has anything to do with 
> enhancements to the DLM.  If existing calls continue to work as before, 
> and only when an optional extra parameter would enable new capabilities, 
> then upward compatibility just cannot be an issue.  At least for this.
>

Is there a version number on the current inter-node DLM messages ?

If not, how can you change the DLM message structure in a compatible way ?

If yes, what happens when an older node sees a later format DLM message ?
You would at least need a compatibility kit to be installed on the older
nodes.

> The optional parameter might be a "lock type", and if not present, 
> existing logic would be used, and if present, new code could be executed 
> to process the new lock type.  Stuff a couple of quadwords into the 
> resource name for the numeric range.  It would add one new piece of data 
> to the DLM data structure(s).
>

What about the DLM messages sent between nodes ?

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.