• r00ty
    link
    fedilink
    194 days ago

    I started playing with rust last week (just converting a couple of C# projects so far), and I’m going to say that once you understand that mutexes/rwlocks are wrappers around the actual data, it (to me at least) feels better.

    Don’t get me wrong, it’s an absolute headache for anyone that’s acquired intermediate or better skill in one of the Cx languages. The paradigm shift is still hitting me hard. But this was one of the differences I actually think is an improvement in probably most use cases.

    • @[email protected]
      link
      fedilink
      163 days ago

      It’s a massive win, and I would question the credibility of any systems programmer that doesn’t recognize that as soon as they understand the wrapper arrangement. I would have to assume that such people are going around making egregious errors in how they’re using mutexes in their C-like code, and are the reason Rust is such an important language to roll out everywhere.

      The only time I’ve ever needed a Mutex<()> so far with Rust is when I had to interop with a C library which itself was not thread safe (unprotected use of global variables), so I needed to lock the placeholder mutex each time I called one of the C functions.

      • @[email protected]
        link
        fedilink
        42 days ago

        The only time I’ve ever needed a Mutex<()> so far with Rust is when I had to interop with a C library which itself was not thread safe (unprotected use of global variables), so I needed to lock the placeholder mutex each time I called one of the C functions.

        Actually I think in this case you’re still better off using a Mutex with “data” inside. I’ve done this before. The idea is that you make a unit struct MyCFuncs or whatever and then you only call the C functions from methods of that unit struct. Then you can only access those methods once you lock the Mutex and get the instance of the unit struct. It feel elegant to me.

        • @[email protected]
          link
          fedilink
          22 days ago

          This makes a lot of sense, but the functions were Rust bindings for plain C functions, they weren’t function pointers. Granted I could have put pointers to the function bindings into fields in a struct and stored that struct in the mutex, but the ability to anyhow call the bindings would still exist.

          • @[email protected]
            link
            fedilink
            12 days ago

            They were also plain C functions in my case, but it doesn’t take too much discipline to only call it through the struct. Also, you can put the struct in a different crate which includes the C bindings to ensure that you can’t call the C bindings without the struct.

      • @sugar_in_your_tea
        link
        53 days ago

        Exactly. If there’s only one thing I could bring from Rust into another language, it would be Mutexes. It’s so nice to guarantee safe access to data.

        • @[email protected]
          link
          fedilink
          English
          5
          edit-2
          2 days ago

          Rust mutexes would be nice. But I think for me that one thing for me would be its enums.

          • @[email protected]
            link
            fedilink
            42 days ago

            But only if pattern matching were included, otherwise they would be as unpleasant as C++'s std::variant.