Ok I'll take a look on PLO. thanks Em sáb., 7 de dez. de 2024, 18:33, Binyamin Dissen < 00001773bcccb823-dmarc-requ...@listserv.uga.edu> escreveu:
> The question is why you would want to use the CMS lock on modern hardware. > > If CS(G) in not adequate for you queue structure, you have PLO or the > various > transaction opcodes. I have used PLO to support a queue with multiple > feeders > and multiple eaters. > > On Sat, 7 Dec 2024 16:40:49 -0300 João Reginato <jb.regin...@gmail.com> > wrote: > > :>Thank you, Peter. I got it and I'm going to use CS instead. > :>But could you send me an example of how to get the CML/CMS locks? > :>The situation is many asids adding data in ecsa and one asid getting this > :>data from there. > :> > :>TIA > :>João > :> > :>-----Mensagem original----- > :>De: IBM Mainframe Assembler List <ASSEMBLER-LIST@LISTSERV.UGA.EDU> Em > nome > :>de Peter Relson > :>Enviada em: sábado, 7 de dezembro de 2024 13:16 > :>Para: ASSEMBLER-LIST@LISTSERV.UGA.EDU > :>Assunto: Re: SETLOCK OBTAIN CML/CMS > :> > :>Regarding CMS lock: > :>CMS is a global suspend lock, you do not need an address space bind to > :>obtain it, but if you are not careful you could adversely impact the > :>performance of the system (blocking the system's access to it while you > hold > :>it). There is rarely call for something outside z/OS itself to obtain > this > :>lock. > :> > :>Regarding CPU lock: > :>Remember that while holding the CPU lock all storage that you touch > :>(including the storage for your program) must be page-fixed or > :>disabled-reference. > :>And while holding the CPU lock (or while in any case of being disabled > for > :>external/IO interrupts) any suspend lock obtain (LOCAL, CML, CMS) can > only > :>be conditional. If the lock is not immediately available, you get control > :>back with an appropriate return code. > :> > :>Regarding SSAR: If this is a reusable ASID, you would have to use SSAIR. > :> > :>Regarding CML: the specific requirement to avoid 073-x'10' upon SETLOCK > :>OBTAIN for a CML is to have either PASN or SASN match the ASID associated > :>with the provided ASCB. > :>The normal way that that happens is via a space-switch PC (setting your > new > :>PASN) and then obtaining the CML of the now-current PASN address space. > :>It is not, in general, safe to SSAR (or SSAIR) to any ASN you might have > a > :>mind to want to access. In many cases, the target of cross-memory access > :>must be non-swappable. > :> > :>All of this leads to the thought that you might want to explain what > :>specifically you feel you are trying to accomplish that necessitates the > :>lock operations (and your questions) so that others can help to guide > you. > :>There is a very real possibility of harm if you get it wrong. Getting it > :>right is part of the responsibility that goes with running in supervisor > :>state (and in this case key 0). > :> > :>Peter Relson > :>z/OS Core Technology Design > > -- > Binyamin Dissen <bdis...@dissensoftware.com> > http://www.dissensoftware.com > > Director, Dissen Software, Bar & Grill - Israel >
