Fun facts about Rust's growing popularity

Re:Fun facts about Rust's growing popularity by randomThoughts9 on Monday October 30, 2017 @08:33AM (#15584494)

I agree and I appreciate what they are trying to do.

But just as a counter-argument, look how a simple lock looks like in Rust [1]:

  fn main() {
      let counter = Arc::new(Mutex::new(0));
      let mut handles = vec![];

      for _ in 0..10 {
          let counter = counter.clone();
          let handle = thread::spawn(move || {
              let mut num = counter.lock().unwrap();

              *num += 1;
          });
          handles.push(handle);
      }

      //...
  }

[1] https://doc.rust-lang.org/book/second-edition/ch16-03-shared...

----- edit: Just to clarify my point. The ownership model is a beautiful solution to the resource management problem. And as the parent pointed out, some concepts can be cleanly borrowed/reused in other languages.

But now, in Rust, in practice, you realize that this model requires a lot of boilerplate code just to make the borrow checker happy, even for simple things like using a lock: create Arc(Mutex(data)); clone the arc reference; move the new Arc reference to the new thread.

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Re:Fun facts about Rust's growing popularity by GlitchMr on Monday October 30, 2017 @12:38PM (#15586443)

The issue really is lack of scoped threads forcing usage of reference counting to figure out when to drop a value. With crossbeam scoped threads implementation this looks much nicer.

    extern crate crossbeam;
    
    use std::sync::Mutex;
    
    fn main() {
        let counter = Mutex::new(0);
        crossbeam::scope(|scope| for _ in 0..10 {
            scope.spawn(|| *counter.lock().unwrap() += 1);
        });
        println!("{:?}", counter);
    }

Four lines to declare a mutex, start 10 threads that all lock that mutex, increase value behind mutex, unlock mutex, and join all spawned threads. There is a lot going on here (unwrap is arguably a noise here however, but the rest is straight to the point).

Also, it's possible to use atomic ints here instead of mutex. Verbosity of mutex actually helps a bit, because locking is fairly expensive and it's better to avoid locking if possible.

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Re:Fun facts about Rust's growing popularity by pjmlp on Monday October 30, 2017 @08:46AM (#15584570)

You can simulate something like that using lambdas in C#.

Something like

    withLock(counter, (num) => {
       return num + 1;
    });

or in alternative,

    withLock(counter, (ref num) => {
       num++;
    });

If C# allowed for trailing lambdas it could look better.

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