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Comment by timschmidt

7 hours ago

Safe threading seems like fully exploiting hardware features to me. That's the biggest thing smart pointers and Rc, Arc, and Cell types enable. Perhaps I could have been clearer.

The comment about memory layout was an additional point that dealing with hardware requires that you format, align, and position information in memory as the hardware expects, which requires either exposing those details, or encoding them in a runtime.

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timschmidt

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fooker  6 hours ago

Safe threading sounds great, as long as the language gets out of my way when I absolutely do not care about safe threading.

I write compilers (and have contributed to the Rust compiler!), and there has been approximately zero times in twenty or so years that thread safety has been a concern.

  • vlovich123  4 hours ago

    I don’t buy at all that you’ve coded in a language like C++ and thread safety has never been a concern. Either:

    1. You work on esoterically simple problems where nothing is worth threading (implied by you questioning whether it bought any meaningful performance).

    2. You code in languages like Rust where it’s not a problem or significantly less of one (Go, Java, c#, Haskell, Ocaml, etc).

    You’re being awfully dismissive of people who’s experiences don’t match yours, especially when it seems like your experience isn’t the norm.

    • fooker  2 hours ago

      Thread safety has not usually been a concern because it’s pretty rare to use raw threads in C++.

      Rust folks always seem to assume people write C++ like it is 1995.

      > implied by you questioning whether it bought any meaningful performance

      This is the first thing you should always ask when you do anything with parallelism! Are you familiar with Amdahl’s law?

  • timschmidt  6 hours ago

    I write a bit of everything, including a little Rust CAD library which is a continuation of work I did in C++ 20 years ago. The C++ version was never multithreaded. The Rust library was fully multithreaded in an afternoon by importing Rayon behind a cargo feature, and using par_iter in place of iter in a few hot loops. That alone made the rewrite worth it.