From b56f5b1c25f81c4f73866a3297b7e39792c617ab Mon Sep 17 00:00:00 2001
From: Andrew Johnson <andrewjohnson@Andrews-MacBook-Pro.local>
Date: Wed, 16 May 2018 15:16:15 -0600
Subject: [PATCH] thread 4

---
 Chapter08/Cargo.toml |  4 ++++
 Chapter08/thread4.rs | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 Chapter08/thread4.rs

diff --git a/Chapter08/Cargo.toml b/Chapter08/Cargo.toml
index 0143bfc..d9329cc 100644
--- a/Chapter08/Cargo.toml
+++ b/Chapter08/Cargo.toml
@@ -37,3 +37,7 @@ path = "thread2.rs"
 [[bin]]
 name = "thread3"
 path = "thread3.rs"
+
+[[bin]]
+name = "thread4"
+path = "thread4.rs"
diff --git a/Chapter08/thread4.rs b/Chapter08/thread4.rs
new file mode 100644
index 0000000..abdbee6
--- /dev/null
+++ b/Chapter08/thread4.rs
@@ -0,0 +1,38 @@
+use std::{thread,time};
+use std::process;
+use std::io::prelude::*;
+extern crate thread_id;
+use std::net::{TcpListener,TcpStream};
+use std::sync::mpsc::{channel,Receiver};
+use std::collections::VecDeque;
+
+fn serve(receiver: Receiver<TcpStream>) {
+   let t = time::Duration::from_millis(10);
+   loop {
+      let mut tcp = receiver.recv().unwrap();
+      let mut buffer = [0; 2048];
+      tcp.read(&mut buffer).expect("tcp read failed");
+      let response = format!("respond from #{}:{}\n", process::id(), thread_id::get());
+      tcp.write(response.as_bytes()).expect("tcp write failed");
+      thread::sleep(t);
+   }
+}
+
+fn main() {
+   let listener = TcpListener::bind("127.0.0.1:8888").unwrap();
+   let mut channels = VecDeque::new();
+
+   for _ in 0..3 {
+      let (sender, receiver) = channel();
+      channels.push_back(sender);
+      thread::spawn(move || {
+         serve(receiver);
+      });
+   }
+
+   for stream in listener.incoming() {
+      let round_robin = channels.pop_front().unwrap();
+      round_robin.send(stream.unwrap()).unwrap();
+      channels.push_back(round_robin);
+   }
+}