I don't think I have coded a "GETMAIN" in anger for over 10 years - STORAGE is just so much more flexible and easier to read/understand.
For what it is worth, if you are writing a medium to large piece of software I would suggest using a local/product macro that front-ends all requests for storage (eg "@STORAGE"). You are then in a position to manage the storage for the software : (o) Invoke the products own "storage manager" functions (if there are any) instead of IBM ones (o) Track/trace storage requests (o) Enforce product standards (o) Do the CHECKZERO=YES stuff automatically for the caller (o) Add other foot-shooting avoidance safeguards for your developers Rob Scott Lead Developer Rocket Software 275 Grove Street * Newton, MA 02466-2272 * USA Tel: +1.617.614.2305 Email: rsc...@rs.com Web: www.rocketsoftware.com -----Original Message----- From: IBM Mainframe Assembler List [mailto:assembler-l...@listserv.uga.edu] On Behalf Of Przemyslaw Kupisz Sent: 25 October 2010 15:55 To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: GETMAIN/FREEMAIN vs. STORAGE OBTAIN/RELEASE W dniu 25.10.2010 15:06, Beate Kawelke pisze: > Hi all, > > I was pretty sure that the STORAGE macros are "better" than GETMAIN/FREEMAIN, > both in terms of functionality and performance. To back that up, I searched > for documentation. > > What I found so far is a fairly recent presentation from SHARE: > http://ew.share.org/client_files/callpapers/attach/SHARE_in_Denver/S1237DB120530.pdf > which says (on page 34) that GETMAIN/FREEMAIN is taking a lot less cycles > than STORAGE OBTAIN/RELEASE (17,000 vs. 20,000). I haven't found any IBM > document saying anything about performance, all I got was that STORAGE is > recommended for some environments (e.g. for AR mode). And then I found a > thread on IBM-MAIN where Peter Relson talked about the relationship between > the two: http://www.mail-archive.com/ibm-m...@bama.ua.edu/msg122945.html but > unfortunately not much about the default LINKAGE=SYSTEM of STORAGE. > > I always thought that an SVC interrupt (GETMAIN) "costs" more than a PC > (STORAGE with LINKAGE=SYSTEM) - am I wrong? > > Anyway: In a "normal" environment (primary mode, key 8), what would you > recommend to use and why? And if you want to "modernize" a module, would you > change from one to the other? > You can find some info here: "10.1.1 Comparison of GETMAIN/FREEMAIN Macros with the STORAGE Macro" http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/IEA2A890/10.1.1?DT=20080602053331 -- Przemyslaw Kupisz
