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Re: Christmas Quiz...

From "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Newsgroups comp.lang.c++
Subject Re: Christmas Quiz...
Date 2022-12-27 13:31 -0800
Organization A noiseless patient Spider
Message-ID <tofo74$3nhm2$3@dont-email.me> (permalink)
References <tod3b8$3c8u8$4@dont-email.me> <cd552208-e199-4e50-9ec5-d0c3f9d7eeeen@googlegroups.com>

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On 12/27/2022 3:42 AM, Michael S wrote:
> On Monday, December 26, 2022 at 11:23:06 PM UTC+2, Chris M. Thomasson wrote:
>> Imagine you are on a SPARC in RMO mode, you are programming in assembly
>> language.
> 
> If I am not mistaken, SPARC RMO is paper spec that was never implemented
> in hardware. Which does not mean that it is impossible to imagine that I am
> programming it in assembler, but it takes stronger imagination than I posses.

SPARC RMO is a real thing.

https://www.linuxjournal.com/article/8212

"Solaris on SPARC uses total-store order (TSO); however, Linux runs 
SPARC in relaxed-memory order (RMO) mode."


> 
>> What memory barrier instruction is the most efficient _and_
>> correct for use _after_ using an atomic RMW instruction to take
>> exclusive access? Think about locking a mutex...
>>
>> A: MEMBAR #LoadLoad
>>
>> B: MEMBAR #LoadStore | #LoadLoad
>>
>> C: MEMBAR #StoreLoad | #LoadLoad
>>
>> D: MEMBAR #StoreLoad | #StoreStore
>>
>>
>> What about the membar we have to use before atomically unlocking this mutex?
>>
>>
>> A: MEMBAR #LoadLoad
>>
>> B: MEMBAR #StoreLoad | #LoadLoad
>>
>> C: MEMBAR #LoadStore | #StoreStore
>>
>> D: MEMBAR #StoreLoad | #StoreStore

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Thread

Christmas Quiz... "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-26 13:22 -0800
  Re: Christmas Quiz... "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-12-26 23:17 +0100
  Re: Christmas Quiz... Bonita Montero <Bonita.Montero@gmail.com> - 2022-12-27 04:59 +0100
    Re: Christmas Quiz... "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-27 13:29 -0800
    Re: Christmas Quiz... "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-04 00:40 -0800
      Re: Christmas Quiz... "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-04 00:41 -0800
  Re: Christmas Quiz... Michael S <already5chosen@yahoo.com> - 2022-12-27 03:38 -0800
  Re: Christmas Quiz... Michael S <already5chosen@yahoo.com> - 2022-12-27 03:42 -0800
    Re: Christmas Quiz... "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-27 13:31 -0800
      Re: Christmas Quiz... Michael S <already5chosen@yahoo.com> - 2022-12-27 14:09 -0800
        Re: Christmas Quiz... "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-27 14:17 -0800
          Re: Christmas Quiz... "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-29 20:42 -0800
  Re: Christmas Quiz... "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-04 00:38 -0800
  Re: Christmas Quiz... "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-17 18:25 -0800

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