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C++ Details of Asymmetric Fences

47 points by anon_farmer ago | 4 comments

ot |next [-]

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.

fschutze |root |parent [-]

Thanks, this is very useful. Reading it I was wondering how applications typically exploit the asymmetric fence, I hope the article you linked help in that regard.

KenoFischer |next |previous [-]

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

jeffbee |next |previous [-]

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 |previous [-]

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