Code shared from the Rust Playground

runloop.rs

// Author: Gabriel Hayes
// Rust Worker-Runloop Implementation

use std::cell::RefCell;
use std::rc::Rc;
use std::time::Duration;
use std::thread;
struct Worker {
    job: Rc<RefCell<FnMut(i64)>>,
}

impl Worker {
    fn new() -> Worker {
        Worker { 
            job: Rc::new(RefCell::new(|_|{}))
        }
    }
    
    fn contract<F: FnMut(i64) + 'static>(job: F) -> Worker {
        Worker {
            job: Rc::new(RefCell::new(job))
        }
    }
    fn work(&mut self, data: i64) {
        let mut closure = self.job.borrow_mut();
        (&mut *closure) (data);
    }
}


struct Runloop {
    workers: Vec<Rc<RefCell<Worker>>>,
    step: i64
}

impl Runloop {

    fn new() -> Runloop {
        Runloop {
            workers: Vec::new(),
            step: 0
        }
    }
    
    fn add_worker(&mut self, worker: Worker) {
        let cell = Rc::new(RefCell::new(worker));
        self.workers.push(cell);
        
    }
    fn run(&mut self, limit: i64) {
        loop {
            self.step += 1;
            if self.step > limit {
                return;
            }
            for worker_cell in self.workers.iter() {
                let worker = worker_cell.clone();
                let worker = &mut *worker.borrow_mut();
                worker.work(self.step);
            }
            thread::sleep(Duration::from_millis(250));
        }
        // Runloop::run(self, limit);
    }
}

fn main() {
    let workers = vec![
        Worker::contract(|a| println!("a = {}", a)),
        Worker::contract(|b| println!("b = {}", b)),
        Worker::contract(|c| println!("c = {}", c)),
        Worker::contract(|d| println!("d = {}", d)),
        Worker::contract(|e| println!("e = {}", e)),
        Worker::contract(|f| println!("f = {}", f))
    ];
    
    let mut runloop = Runloop::new();
    for worker in workers {
        runloop.add_worker(worker);
    }
    runloop.run(50);
}