My tests with GTF in 1987-1988 indicated that whichever application - GTF or TMON/MVS - was started first would succeed in using the MC control block structure and whichever application was started next would suffer a S0F6 (or maybe S0F8) ABEND. I produced a work-around in about 3 weeks of intense effort. At that time I had access to GTF microfiche. I was very pleased a few years ago when I was able to start my own GTF address space when another one was already running and there was no ABEND. I came to the same conclusion you did about the original intent's being to have a multiplicity of applications running simultatneously because of a common on one of the fields in one of the control blocks which said something like "address of next whatever control block in the queue of applications".
Bill Fairchild Franklin, TN “Political language is designed to make lies sound truthful and murder acceptable, and to give the appearance of solidity to pure wind.” [George Orwell] ----- Original Message ----- From: "Jim Mulder" <[email protected]> To: [email protected] Sent: Thursday, May 2, 2013 5:17:08 PM Subject: Re: GTF IHL007I Terminating on Error > TMON/MVS (possibly under a newer name than when I developed this > part of it in 1987) sets itself up as an application using the > Monitor Call Trace Facility when and only when a short-duration I/O > trace is requested by a TMON/MVS user . It removes all its Monitor > Call control blocks when the trace ends. Unless that code has been > modified since I last worked with it 20 years ago. That's good to know. The Monitor Call interface in z/OS has never been externally documented (to my knowledge), and the internal macro for invoking it is PL/S(AS)(X) - only. Althought it appeared that the ancients (before my time) who orginally design this interface were intending to allow multiple concurrent appplications, it looks like at some they gave up on getting that working, and restricted it to one application (GTF) at a time. But, it was GTF initialization that enforced the restriction, not the Monitor Call interface code. So I don't know what would happen if this TMON function was active at the same time as GTF. In z/OS 1.6, there was a line item to remove this restriction, to allow multiple concurrent GTFs. Which eventually (after a number of PTFs) mostly seems to work. There were still some remaining issues relating to GTRACE TEST, and GTFTRACE under IPCS, when multiple GTFs are active, that I am working on fixing in z/OS 2.1 Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
