A reentrant program need not use GETMAIN/FREEMAIN/STORAGE. I've written zillions of reentrant routines that rely on the caller to provide a work area or that rely on pre-allocated storage areas (usually PC routines).
Using pre-allocated or caller-specified work areas is extremely fast. If a caller provides a work area that is allocated within itself, then the caller is non-reentrant, but the called routine is still reentrant. Jeffrey D. Smith Principal Product Architect Farsight Systems Corporation 700 KEN PRATT BLVD. #204-159 LONGMONT, CO 80501-6452 303-774-9381 direct 303-484-6170 FAX http://www.farsight-systems.com/ comments are invited on my encryption project > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On > Behalf Of John P Baker > Sent: Saturday, October 21, 2006 10:17 AM > To: [email protected] > Subject: Re: Is the teaching of non-reentrant HLASM coding practices ever > defensible? > > If the reentrant program must acquire and release storage (via > GETMAIN/FREMAIN or STORAGE ACQUIRE/RELEASE) during each invocation, I can > not see how the operation of the internal cache is going to make a > difference of sufficient significance to support the performance > assertion. > > If the reentrant program does not have to invoke these or other system > services, it may be a different matter. In fact, I would expect the > performance characteristics to be quite different. > > My experience is that the assertion that reentrant programs ALWAYS perform > better than non-reentrant programs can not be justified. There are simply > too many variables involved. > > John P Baker /snip/ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
