> I am trying to shoot a bug. I *know* I have a design/logic error in that I > am referencing a cell *after* returning it with CPOOL FREE. But I am trying > to figure out if I have another error also. Does anyone know: does CPOOL > FREE use the first four or so bytes of a cell for its own purposes following > FREE? In other words, does CPOOL FREE clobber the first few bytes of a cell? > Maybe with a cell or related address? > > CPOOL BUILD,PCELLCT=(R2),SCELLCT=(R4), + > CSIZE=(R3),SP=SP_ToUse,KEY=0, + > LOC=(31,31),CPID=AV_Cell_Recd, + > MF=(E,CPOOLMFL) > > CPOOL FREE,CPID=AV_Cell_Recd,CELL=(R8),REGS=USE
The first 4 bytes of a freed cell contains the address of the next cell on the available cell chain. The next 12 bytes after that may also get modified by CPOOL FREE if you are using the undocumented DIAGxx TRAP which searches the available chain to see if the cell you are trying to free is already freed. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
