Systems Programming in Distributed, Multicore World with Go, Rust, and Parasail | Hacker News Reader

Systems Programming in Distributed, Multicore World with Go, Rust, and Parasail

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51 pointsxkarga009 comments

This article pops up every so often, so again I should emphasize that the concurrency story in Rust has changed greatly in the interim (and will continue to change as new approaches to concurrency are fleshed out in the stdlib).

Can someone experienced in both Rust and Go comment on how the two languages compare regarding concurrency? Is it more flexible having it in stdlib vs being baked into the language? I regard myself as fairly experienced in Go and find its concurrent primitives really straightforward to use. The whole goroutines-channels-select package feels like a very powerful and easy to use tool for concurrent code (though you can still shoot yourself in the foot).

It is a great deal more flexible having concurrency constructs built as library features as opposed to baked into the language. If the constructs provided don't make the same performance tradeoffs that your use case demands, you can build your own. These can provide safe, statically verified APIs by leveraging Rust's ownership and lifetime semantics.

Unfortunately channel selection and futures are still pretty raw at the moment (it remains to be seen if it will be ready for 1.0), but other constructs such as threads, channels and mutexes are looking pretty strong for 1.0.

Here is a video of a talk the author, Tucker Taft, gave about the ParaSail language at Mozilla last year:

https://air.mozilla.org/region-based-storage-management-para...

Seems like this is a better source of the article: http://parasail-programming-language.blogspot.com/2013/04/sy...

Unfortunately, it's a "why X is great, by the vendors of X" article. It's an ad for ParaSail, which is too new (and possibly too weird) to have much traction yet.

Note that the document seems to be from the spring of last year.

I think it is interesting that Parasail has no explicit pointers and only uses value semantics. This means that no garbage collection is needed: the storage associated with a variable is freed when the variable goes out of scope, or when the variables value is set to null (and yes, you must have a value of type Optional T in order to set it to null). I thought that having pure value-semantics would be too costly in a language, but apparently that kind of solution has its place after all.

can you clarify how value semantics are costly compared to garbage collection/explicit pointers?

As far as I understand, and if no extra care is taken on the part of the programmer: the extra copying, since you would have to copy over the data from one variable to another instead of just using and moving around pointers. In Parasail's case, you can choose to use "move" (move value from left side to over to the right side) and "swap" (swap the values of the left and right side), which will avoid the copying.

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