Re: User Space problems.

[Mel Rothman <mel@xxxxxxxxxxxxxx>]

Scott,

I've had success extending a user space.  After creating the the user space, 
the change user space attribute (QUSCUSAT) API is used to make it extendible.

In a small test program, I created a 1024 byte user space and extended it to 
over 15 MB with 300 writes of 50,000 bytes each.

The code to change the extendibility attribute, copied from CGIDEV2's XXXUSRSPC 
module is:

D rtnlib          s             10
D QualUsrSpc      s             20
D AttrToChg       ds
D  attrcount                    10i 0 inz(1)
D  attrkey                      10i 0 inz(3)
D  attrlen                      10i 0 inz(1)
D  attrvalue                     1    inz('1')
D qusec           ds
D  qusbprv                      10i 0 inz(%size(qusec))
D  qusbavl                      10i 0 inz(0)
D  qusei                         7
D                                1
D  msgdata                     500

 * Make user space automatically extendible
C                   call      'QUSCUSAT'
C                   parm                    rtnlib
C                   parm                    qualusrspc
C                   parm                    AttrToChg
C                   parm                    qusec

For more information about CGIDEV2, see http://www-922.ibm.com/

Mel Rothman, CGIDEV2 Author
Mel Rothman, Inc.

Scott Klement wrote:
> I've had bad experiences with "automatically extending" user spaces.  I've
> found things work much better if you first calculate how big the user
> space can be and use that to create it.
>
> Is it just me, or do users spaces only "automatically extend" for APIs
> which are designed for it?   Are they intended to expand when they're
> populated by my own programs?  I've never managed to get them to do so.
>
>
>
> > The point where the User space crash occurs it is hardly loaded upto
> > even 1 MB. Still we face this problem. What do you reckon could be the
> > problem.