Let me come right out and say I am asking a potentially dumb question here.
I freely admit I have never used pseudo-registers or any of the associated
features. (Level set: yes, I am totally familiar with the meaning of
reentrant and reusable and have coded lots of "do-it-yourself" reentrant
code in 360+ assembler.)
Why am I asking a dumb question here? Because I don't see much if any
overview of the topic in the docs, just detail instruction documentation,
and I don't know where else to turn. If anyone could suggest a source for an
education in pseudo-registers and related features, I'm all ears.
Does DXD help solve this problem? If I code
FOO DXD F
BAR DC Q(FOO)
does that give me a fullword that will be "task-unique" at run time? Will
GETMAIN ...
L R2,BAR Point to unique storage pointer
ST R1,0(,R2) Save my storage area for subsequent use
do what the comments say it does? Is this code -- assuming the usual other
requirements are met -- satisfy reentrancy? Or am I off base?
Environment: Pre-linker, PDS, and "OS" linkage from LE C. Why pre-linker and
not binder/PDSE? Two reasons: trying to solve one learning curve at a time,
and hoping to avoid PDSEs because of all of the "customer resistance"
reasons mentioned in a recent thread on IBMMAIN. (Please don't try to
convince me that PDSEs are cool. I have no personal problem with them. I am
in the software product business, and the customer objections are a fact,
even if some think they are baseless. You don't sell software by arguing
with the prospects.)
Charles
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf
Of Don Poitras
Sent: Tuesday, February 23, 2010 8:22 AM
To: IBM-MAIN@bama.ua.edu
Subject: Re: Best practice for 24-bit storage in assembler called from C/C++
> This really depends on how you get access to the program with the WSA. If
> you load a program once and put the address in commonly retrievable area
> (vector table, name/token pair, etc.) then WSA does not provide
reentrancy.
We're back to talking about something other than batch programs. The OP
wasn't asking to write a system service, just a job that builds a DCB in
assembler.
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