The following message is a courtesy copy of an article that has been posted to bit.listserv.ibm-main,alt.folklore.computers as well.
[EMAIL PROTECTED] (Lindy Mayfield) writes: > What doesn't is that Cannatello's book has a page and a half on doing > POST, with one example of how to change the ECB without using the POST > macro. > > He even has the child checking the ECB to see if a WAIT had been issued. A.6.3.1 Bypass Post Routine http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DZ9ZR003/A.6.3.1?SHELF=DZ9ZBK03&DT=20040504121320&CASE= from above: The following routine allows the SVC "POST" as used in MVS/ESA to be bypassed whenever the corresponding WAIT has not yet been executed, provided that the supervisor WAIT and POST routines use COMPARE AND SWAP to manipulate event control blocks (ECBs). ... snip ... i.e. charlie had been working on fine grain multiprocessor locking for cp67 at the science center http://www.garlic.com/~lynn/subtopic.html#545tech when he invented the compare&swap instruction http://www.garlic.com/~lynn/subtopic.html#smp note compare&swap was chosen because CAS are charlie's initials. trying to get the instruction into the 370 architecture was initially rebuffed since the pok favorite son operating system claimed that test&set ... carried forward from 360 multiprocessor days, was all that was necessary. the statement was made that in order to get compare&swap into 370 architecture required coming up with uses that weren't multiprocessor specific. came up with the multitasking/multithreaded examples ... which were included in the compare&swap programming examples. A.6 Multiprogramming and Multiprocessing Examples http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DZ9ZR003/A.6?SHELF=DZ9ZBK03&DT=20040504121320 more recently the perform locked operation instruction was defined ... and added to the above description. ---------------------------------------------------------------------- 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
