On Fri, 29 Jan 2016 08:52:00 +1100, Peter Morrison wrote: > >I have been following the COBOL V5 debate with interest, > >Currently, when using the binder to create a program object, the output load >library MUST be a PDSE. > No. (I believe) It might instead be a UNIX directory.
>There is a lot of animosity about PDSEs. They have been around for many >years. But, when it comes to sharing them across systems and/or Sysplexes, >IBM still haven't gotten it right. > UNIX directories can be shared across systems with zFS sharing and across plexes with NFS. Even to non-z systems. IBM got that right; integrity is maintained. >PDS's can be put on a shared pack and be shared across multiple systems >and/or Sysplexes. Of course, you had better not try to update them >simultaneously from several places or bad things can happen. Sites that do >the sharing usually have procedures in place for that. > >Looking at the IHAPDS map (in SYS1.AMODGEN), which maps a load module (or >program object.) PDS entry returned by BLDL, and the directory data on disk, >there is a flag that can be used by a program to distinguish a program >object from a load module. There is an optional extension that has larger >offsets (greater than 3 bytes.) > >SO, what if that bit was set in a directory entry on disk in a PDS load >library? That could mean that the actual data in the PDS member was a >program object, not a load module, and be handled appropriately by the >system loader. Then, you would get all the advantages of a program object >with none of the problems associated with a PDSE. (The issues associated >with long alias names are not covered here. But note that when it comes to >execution, you need an 8-character name anyway - look at the LOAD etc. >macro(s) for example) > >(The binder could have a special option that would tell it to put a program >object in a PDS - to override the default of putting a load module there) > The bad news: UNIX directories must not appear in STEPLIB (I think; I haven't tried it) nor in LINKLIST. They oughta fix that. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
