This is refreshable, and even runs on S/360

         L     R15,PTR
         LTR   R15,R15
         BNZ   CALLIT
         ...        ...                                    Code that always 
leaves the same value in R15
         ST    R15,PTR
CALLIT   BALR  R14,R15
         ...
PTR      DC    A(0)

This is reentrant, and requires at least S/370

RETRY    L     R1,COUNTER
         LA    R0,1(,R1)
         CS    R1,,R0,COUNTER
         BNE   RETRY
         ...
COUNTER  DC    F'0'

I would consider either to be bad form.


--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3

________________________________________
From: IBM Mainframe Discussion List [[email protected]] on behalf of 
Binyamin Dissen [[email protected]]
Sent: Sunday, February 7, 2021 1:40 PM
To: [email protected]
Subject: Re: LINK vs LOAD/CALL

On Sun, 7 Feb 2021 16:52:55 +0000 Seymour J Metz <[email protected]> wrote:

:>Second, you can write code that is reentrant and refreshable, modifies itself 
.......

Only possible if it modifies itself but pays no attention to the modified
area.

Not really relevant.

--
Binyamin Dissen <[email protected]>
http://secure-web.cisco.com/19fzBBFfAFBx8PysD0V3qJwF9qE3g50-el2X9G9hk1S6e6J1OJCsS3iW5Z4sW_eIxmVeSUtphiZ1F_hVA17R0eQ0sISoKmaje1LKLxW5hXXG57Bhp2jgb7tfsyTUCz7uR3oi_3QvypHyqrkZbk90NkCCElTsVY_WlQLUN3ZGkDG1kO6WKuK6QjZMrhjWBiYf0C9yl8O8I4qv3EpHVq2VRzt08kpxpmxsg6gnybjtHX8YvBuUnV69On_Zzc0LY2kT7e31qhCg19eAfUSCspghB948WQ7TW-XVS3W0hjnawFDJuSq_Gu6Ik-pJsBZ9JBai6AHJCbw-0jDqyvmh1mpiJaD4SemvF8t211o_Xhkk4-K9gYDgDLDpWbiole96yIwNk6hI6rfM33dkqiO-w6cJY6yIpcdBe1cjlMlsHJsUJGWjQHoOCTBflbOxTayrH2erW/http%3A%2F%2Fwww.dissensoftware.com

Director, Dissen Software, Bar & Grill - Israel


Should you use the mailblocks package and expect a response from me,
you should preauthorize the dissensoftware.com domain.

I very rarely bother responding to challenge/response systems,
especially those from irresponsible companies.

----------------------------------------------------------------------
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

Reply via email to