Locking workers

src/lib.rs

 use std::thread;
+use std::sync::{mpsc, Mutex, Arc};
 
 pub struct ThreadPool{
     workers: Vec<Worker>,
+    sender: mpsc::Sender<Job>,
 }
 
+type Job = Box<dyn FnOnce() + Send + 'static>;
+
 impl ThreadPool {
     pub fn new(size: usize) -> ThreadPool {
         assert!(size > 0);
 
+        let (sender, receiver) = mpsc::channel();
+
+        let receiver = Arc::new(Mutex::new(receiver));
+
         let mut workers = Vec::with_capacity(size);
 
         for id in 0..size {
-            workers.push(Worker::new(id));
+            workers.push(Worker::new(id, Arc::clone(&receiver)));
         }
 
         ThreadPool {
-            workers
+            workers,
+            sender,
         }
 
     }
 
     pub fn execute<F>(&self, f: F)
-        where F: FnOnce() + Send + 'static {
-
+        where F: FnOnce() + Send + 'static 
+    {
+        let job = Box::new(f);
+        self.sender.send(job).unwrap();
     }
 
     // pub fn spawn<F, T>(f: F) -> JoinHandle<T> 
 }
 
 impl Worker {
-    fn new(id: usize) -> Worker {
-        let thread = thread::spawn(|| {});
+    fn new(id: usize, receiver: Arc<Mutex<mpsc::Receiver<Job>>>) -> Worker {
+        let thread = thread::spawn(move || {
+            loop {
+                let job = receiver.lock().unwrap().recv().unwrap();
+
+                println!("Worker {} got a job, executing.", id);
+
+                job();
+            }
+        });
 
         Worker {
             id,