Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c++ > #88388

Re: Christmas Quiz...

From "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Newsgroups comp.lang.c++
Subject Re: Christmas Quiz...
Date 2023-01-04 00:38 -0800
Organization A noiseless patient Spider
Message-ID <tp3du0$2dmo3$8@dont-email.me> (permalink)
References <tod3b8$3c8u8$4@dont-email.me>

Show all headers | View raw

On 12/26/2022 1:22 PM, Chris M. Thomasson wrote:
> Imagine you are on a SPARC in RMO mode, you are programming in assembly 
> language. 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

A hint. A mutex does not need #StoreLoad ordering.

Back to comp.lang.c++ | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

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

csiph-web