IBM Mainframe Assembler List <[email protected]> wrote on 09/20/2010 04:51:25 PM:
> >> I was going to make the same comment. There are a number of other > >> macros which have such a version field to indicate the mapping of the > > > parm fields etc. The code can thus do fall-back if it is presented > > > with a "downlevel" parm. The problem is that there is no such field > >> in the parm list now so it would be hard to introduce it at this > >> point. > > > > The length field (RASDLEN) has been used in prior releases to > >compatibly extend the area in which data is returned to the requestor. > >However, RASDLEN includes some internal working storage as well as > >the area in which data is returned. If an increase in > >internal working storage is required to process requests which > >were formerly be processed with a smaller amount, this cannot > >be done compatibly. About the best that could be done in that > >case would be to fail the request with a return code of 8, > >which is documented to mean > >"The parameter list is too small." > >That would be incompatible, but at least not destructive. > > This would met my "The code can thus do fall-back if it is presented > with a "downlevel" parm." criteria. My question on your reply is how > would the code know that the RASDLEN is too small? It was my > impression that the issue was that a work area was being allocated > and was too short and thus there was an overlay beyond the end of the > short workarea and that there was no indication in the parms of the > length of that workarea. The invoker of the SYSEVENT provides an area of storage, and sets RASDLEN to be the size of the area of storage it is providing. The SYSEVENT uses some of this area for returning data, and some as an internal work area. The code could be aware of the amount it needs for each purpose, and thus can check against RASDLEN to see if enough has been provided. The code was only using RASDLEN to determine how much data it could return (probably on the assumption that the amount it used for internal work area would never be increased). So when that was increased, it broke things. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY
