Scott,

Yes, a data space is deleted when its owning address space goes away.  You
can use ALESERV EXTRACT from another address space, passing the ALET to
retrieve and validate the STOKEN.  And have good recovery mechanisms in
place.

Also, the owning data space must be non-swappable while other address spaces
are accessing the data space.

These and other considerations make 64-bit common an attractive alternative.
If you've written code to access data in a data space, accessing data above
the bar is conceptually not that different.  You have to develop the same
sorts of habits of mind, whether you're dealing with access registers or the
high-order halves of 64-bit registers.

Best,
Steven St.Jean

> -----Original Message-----
> From: IBM Mainframe Discussion List [mailto:[email protected]] On
> Behalf Of Scott Ford
> Sent: Saturday, December 08, 2012 2:07 PM
> To: [email protected]
> Subject: Re: Common Data Space Basics
> 
> Steven,
> 
> I am correct in assuming that the dataspace must be created by a running
> STC or JOB, and when shutsdown the dataspace Is deleted ?
> 
> Scott ford
> www.identityforge.com
> 
> Tell me and I'll forget; show me and I may remember; involve me and I'll
> understand. - Chinese Proverb
> 
> 
> On Dec 8, 2012, at 12:53 PM, "Steven St.Jean" <[email protected]> wrote:
> 
> > Donald,
> >
> > That's right.  Any address space with the token can access the data
> space.
> >
> > Something like this:
> >
> > *************************************************************
> > *    Create the Dataspace                                   *
> > *************************************************************
> >     DSPSERV CREATE,                                         +
> >           NAME=dspname,                                     +
> >           SCOPE=COMMON,                                     +
> >           KEY=8*16,                                         +
> >           STOKEN=stoken,       Where to put the STOKEN      +
> >           BLOCKS=(max,init),   Size of dspc (max,init)      +
> >           ORIGIN=origin
> >     LTR   R15,R15
> >     BNZ   fail
> > *
> > *************************************************************
> > *    Obtain an ALET for the Dataspace
> > *************************************************************
> >     ALESERV ADD,ALET=alet,                                  +
> >           STOKEN=stoken,                                    +
> >           CHKEAX=NO,                                        +
> >           AL=PASN,                                          +
> >           ACCESS=PUBLIC
> >     LTR   R15,R15
> >     BNZ   fail
> >     ...
> >     ...
> > STOKEN     DS XL8         STOKEN of dataspace
> > DSPNAME    DS CL8         Name of dataspace
> > ALET       DS AL4         ALET of dataspace
> > MAX        DC F'4096'     Max size in 4Kb blocks
> > INIT       DC F'2048'     Max size in 4Kb blocks
> > ORIGIN     DS AL4         Address of first byte of dataspace
> > ************************************************************
> >
> > Hope this helps.
> >
> > Best,
> >
> > Steven St.Jean
> > http://sdsusa.com
> >
> >
> >> -----Original Message-----
> >> From: IBM Mainframe Discussion List [mailto:[email protected]]
> >> On Behalf Of Donald Likens
> >> Sent: Friday, December 07, 2012 3:50 PM
> >> To: [email protected]
> >> Subject: Common Data Space Basics
> >>
> >> I've studied the manuals but before I start coding to use a Common
> >> Data Space I want to confirm that for a common data space access is
> >> by the PASN-AL and the ALESERV creates a PASN-AL for all the address
> spaces.
> >>
> >> So all I have to do is issue the DSPSERV
> >> CREATE,TYPE=BASIC,SCOPE=COMMON and ALESERV ADD,AL=PASN once and pass
> >> the ALET to all address spaces that access this dataspace. Correct?
> >>
> >> Is there additional overhead accessing data spaces as opposed to
> >> accessing primary storage? (I expect not) If an address space is
> >> created after the ALESERV macro is executed, can the new address
> >> space access the data space?
> >>
> >> ---------------------------------------------------------------------
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> >> IBM-MAIN
> >
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