1 files changed, 117 insertions, 0 deletions
diff --git a/hello_server/src/lib.rs b/hello_server/src/lib.rs
new file mode 100644
index 0000000..cd1f616
--- /dev/null
+++ b/hello_server/src/lib.rs
@@ -0,0 +1,117 @@
+use std::sync::Arc;
+use std::sync::Mutex;
+use std::sync::mpsc;
+use std::thread;
+
+enum Message {
+    NewJob(Job),
+    Terminate,
+}
+
+trait FnBox {
+    fn call_box(self: Box<Self>);
+}
+
+impl <F: FnOnce()> FnBox for F {
+    fn call_box(self: Box<F>) {
+        (*self)()
+    }
+}
+
+type Job = Box<FnBox + Send + 'static>;
+
+pub struct ThreadPool {
+    workers: Vec<Worker>,
+    sender: mpsc::Sender<Message>,
+}
+
+impl ThreadPool {
+    pub fn new(size: usize) -> Result<ThreadPool, &'static str> {
+        if size <= 0 {
+            return Err("failed to create pool");
+        }
+
+        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, Arc::clone(&receiver))?);
+        }
+
+        Ok(ThreadPool {
+            workers,
+            sender,
+        })
+    }
+
+    pub fn spawn<F, T>(f: F) -> thread::JoinHandle<T>
+        where
+            F: FnOnce() -> T + Send + 'static,
+            T: Send + 'static
+    {
+        thread::spawn(f)
+    }
+
+    pub fn execute<F>(&self, f: F) 
+        where 
+            F: FnOnce() + Send + 'static 
+    {
+        let job = Box::new(f);
+        self.sender.send(Message::NewJob(job)).unwrap();
+    }
+
+}
+
+impl Drop for ThreadPool {
+    fn drop(&mut self) {
+        for _ in &mut self.workers {
+            self.sender.send(Message::Terminate).unwrap();
+        }
+
+        println!("shutting down all workers...");
+
+        for worker in &mut self.workers {
+            println!("shutting down worker {}", worker.id);
+
+            if let Some(thread) = worker.thread.take() {
+                thread.join().unwrap();
+            }
+        }
+    }
+}
+
+struct Worker {
+    id: usize,
+    thread: Option<thread::JoinHandle<()>>,
+}
+
+impl Worker {
+    pub fn new(id: usize, receiver: Arc<Mutex<mpsc::Receiver<Message>>>)
+        -> Result<Worker, &'static str>
+    {
+        let thread = thread::spawn(move || { 
+            loop {
+                let message = receiver.lock().unwrap().recv().unwrap();
+
+                match message {
+                    Message::NewJob(job) => {
+                        println!("worker {} got job, executing...", id);
+                        job.call_box();
+                    },
+                    Message::Terminate => {
+                        println!("worker {} was told to terminate...", id);
+                        break;
+                    },
+                }
+            }
+        });
+
+        Ok(Worker {
+            id,
+            thread: Some(thread),
+        })
+    }
+}