I too have run into this ordering anomaly, not often, just once as I recall.
Thank you for the excellent explanation! -----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of Jim Mulder Sent: Thursday, March 4, 2021 3:09 PM To: [email protected] Subject: Re: A Tale of Interleaving WTO messages Caution! This message was sent from outside your organization. When the WTO LINKAGE=SVC is issued in the Console address space, A broadcast SSI WTO call is done. JES2 has a WTO function routine (that's how WTOs get into the job log). The JES2 routine sees that it is running in the Console address space, and thus it does not have addressability to the job log control blocks and buffers in your job's address space. So it schedules an SRB to your job's address space. The SRB routine schedules an IRB to the initiator task in your address space, and the IRB routine adds the message to your job log. The dispatching and execution of the SRBs, and the dispatching of the IRBs, for messages issued close together, provides opportunity for the messages to not be added to the job log in the same order as the branch entry WTOs. Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY "IBM Mainframe Assembler List" <[email protected]> wrote on 03/04/2021 09:13:09 AM: > From: "[email protected]" <[email protected]> > To: [email protected] > Date: 03/04/2021 11:07 AM > Subject: A Tale of Interleaving WTO messages Sent by: "IBM Mainframe > Assembler List" <[email protected]> > > . > . > Jim Mulder wrote, > >When you do a WTO with LINKAGE=BRANCH, the request is added to a > >message queue which is serviced asynchronously by a TCB in the > >CONSOLE address, which issues WTO LINKAGE=SVC for each queued > >message. So you should have no expectations about the delivery > >ordering between a WTO with LINKAGE=SVC and a WTO with > >LINKAGE=BRANCH. > > > > > If all the WTOs with LINKAGE=BRANCH are submitted from the same > address space and from the same TCB, why wouldn't these WTO messages > arrive in sequence and get queued in the Console Address Space in the > order they were submitted ? > . > Paul
