>applicable to 99%+ of all serialization scenarios you encounter To be frank, you might not have very complex serialization requirements. Also, using PLO when CS,CSG,CDS,CDSG would do is a significant waste of cycles. For the cases I have seen within our code, uses of PLO (in the cases where it is not better to use something simpler) are a tiny percentage of our serialization needs.
>When the updating process wakes up S0C4! Using PLO to update a free queue, as is the case with CPOOL and its CDS-based free-queue protocol, requires that the queue elements *never* be freed (unless you like potentially blowing up or, worse, overlaying something you didn't intend to write into). Perhaps this is not well understood. >I really don't see the big deal with an 0c4 in this scenario (should happen rarely) That's a scary statement. If you get an 0C4 you could probably deal with it. The real risk is the case where you don't get an 0C4 because the storage was re-allocated and used for something else and now it does not program check but overlays something. >I think I figured out a solution: There are a lot of details missing in what was shown, but if you want my honest suspicion, it's that if this is a "free queue" type of protocol, it will not work. The reason that the free queue protocol needs a sequence number is because even if the header "matches", the values that you need to put into your new element for the "next" and/or "previous" may no longer be correct due to a set of additional asynchronous operations. Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
