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C++ Details of Asymmetric Fences

47 points - last Friday at 5:25 PM

Source
  • ot

    today at 3:47 PM

    This is a great article but it goes into a lot of detail that can be intimidating at first.

    For me, the reading that made asymmetric fences "click" is this: https://pvk.ca/Blog/2019/01/09/preemption-is-gc-for-memory-r...

    It might be easier to read that first, as it also goes into practical applications, and then this one.

    • KenoFischer

      today at 5:36 PM

      I also just added these to Julia for 1.14 (https://github.com/JuliaLang/julia/pull/60311).

      • jeffbee

        today at 4:15 PM

        I can't help myself digging into the referenced source code. The membarrier syscall can fail to allocate, returning ENOMEM. The way Folly calls it, the program would abort. Which I guess is a fair strategy but it's good to know when your synchronization primitive is actually SynchronizeOrCrash.

        • nttylock

          today at 2:00 PM

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