On Tue, Sep 22, 2015 at 11:25 AM, Phil Smith <[email protected]> wrote:
> To find the TIOT, a colleague uses GETDSAB, then pulls DSABTIOT out of > that. I've always seen: > L R3,540 Get TCB address > L R3,12(,R3) Get TIOT address > ...which seems a tad bit mo' shorter :) > > Looking at GETDSAB, it's beautifully commented with over 500 lines of > preamble, none of which explain what the DSAB is or why one would want to > get one (OK, that's a different rant - z/OS doc in general is really short > on theology; z/VM doc is MUCH better about this). > So the real question: I expect GETDSAB is the documented interface, but is > the two-line approach common? Aside from theoretical changes, is there any > reason not to use it? > ​Personal opinion. The above code has worked since, at least, OS/MVT. But, as mentioned by others, it only works for the TIOT​. GETDSAB is an architected API. Which, for me, "seals the deal" about which should be used. My basic philosophy, any more, is use a documented, architected API when such will do the job. Even if it is overkill for the current need. Mainly because clever code will likely need to be maintained by those who are not so clever. Of course, there is a penalty for doing this. Your code will most likely consume more CPU. If this is a DIE exit or something done thousands of times a minute, this become the overriding consideration. If this is an hourly batch job which runs for 5 minutes, who really cares? > > ...phsiii > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > -- Schrodinger's backup: The condition of any backup is unknown until a restore is attempted. Yoda of Borg, we are. Futile, resistance is, yes. Assimilated, you will be. He's about as useful as a wax frying pan. 10 to the 12th power microphones = 1 Megaphone Maranatha! <>< John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
