In a recent note, Edward E. Jaffe said: > Date: Thu, 16 Jun 2005 22:41:17 -0700 > > Paul Gilmartin wrote: > > >I had thought that for different processors; more likely on different > >systems (have I got that term right?) in a sysplex, it is possible that > >a = b; in fact that is the rationale for providing the programmable > >value -- it guarantees uniqueness overall. So, if the processor with > >the higher programmable value does a STCK[E] very shortly before the > >processor with the lower programmable value so a = b, the first STCKE > >will store a higher value than the second. The question is whether > >any event, or communication between processors, in so short an interval > >(less than one clock tick) can manifest monotonicity violation. > > I believe the use of STCKSYNC by very sensitive multi-system routines > reduces the possibiliy of this to zero. > Is this simply because the STCKSYNC macro necessarily takes so long to execute that the possibility of such overlap as I envision is removed? Any means of introducing a sufficient delay would prevent the behavior.
-- gil -- StorageTek INFORMATION made POWERFUL ---------------------------------------------------------------------- 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
