On Mon, Apr 7, 2014 at 9:31 AM, Paul Gilmartin <[email protected]> wrote:

<snip>

> >My personal opinion is that the advantage of this is not worth the cost to
> >implement. And there are more questions. Is this a SHARED or EXCLUSIVE
> >enqueue? Oh, that would be the DISP-equivalent, I guess. Hum, when is the
> >ENQ issued? At start of job, like for SYSDSN, or at start of STEP? If this
> >is an exclusive ENQ, should there be two ENQs; one for the entire DSN &
> one
> >for the DSN+MEMBER? The DSN-only is what ISPF uses before it does a SAVE.
> >This is to serialize writing into a PDS (which is not needed for a PDSE)
> to
> >avoid "member data interleaving".
> >
> Is that SYSDSN?  If so, that would upgrade any existing SHR ENQ to EXC.
> If on z/OS 2.1, will ISPF downgrade that ENQ to SHR afterward?
>
>
Hum, I don't see the need to downgrade. From what I understand, when a user
does an ISPF editor SAVE command, ISPF does:

ENQ SPFEDIT dsn OLD
write out to PDS
STOW to update the PDS directory
DEQ SPFEDIT dsn

That is, ISPF does not have a SHR enqueue on the DSN alone except while
doing a SAVE.

<snip>

 -- gil

-- 
There is nothing more pleasant than traveling and meeting new people!
Genghis Khan

Maranatha! <><
John McKown

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