From 4d4ba2d5f703969851742798e79e16333fb9ca9a Mon Sep 17 00:00:00 2001
From: Martin Pitt <martin@piware.de>
Date: Sun, 19 Sep 2021 10:38:31 +0200
Subject: [PATCH] simple-http: Add scaffolding for thread pool implementation

Turn into library crate. Add ThreadPool stub to src/lib.
---
 simple-http/src/{ => bin}/main.rs |  5 +++-
 simple-http/src/lib.rs            | 40 +++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)
 rename simple-http/src/{ => bin}/main.rs (93%)
 create mode 100644 simple-http/src/lib.rs

diff --git a/simple-http/src/main.rs b/simple-http/src/bin/main.rs
similarity index 93%
rename from simple-http/src/main.rs
rename to simple-http/src/bin/main.rs
index 0993075..ff3af27 100644
--- a/simple-http/src/main.rs
+++ b/simple-http/src/bin/main.rs
@@ -5,6 +5,8 @@ use std::net::TcpStream;
 use std::time::Duration;
 use std::{fs, str, thread};
 
+use simple_http::ThreadPool;
+
 fn handle_connection(mut stream: TcpStream) {
      let mut buffer = [0; 1024];
 
@@ -61,9 +63,10 @@ fn handle_connection(mut stream: TcpStream) {
 
 fn main() {
     let listener = TcpListener::bind("127.0.0.1:7878").unwrap();
+    let pool = ThreadPool::new(4);
 
     for stream in listener.incoming() {
         let stream = stream.unwrap();
-        thread::spawn(|| handle_connection(stream));
+        pool.execute(|| handle_connection(stream));
     }
 }
diff --git a/simple-http/src/lib.rs b/simple-http/src/lib.rs
new file mode 100644
index 0000000..ff8bc4f
--- /dev/null
+++ b/simple-http/src/lib.rs
@@ -0,0 +1,40 @@
+use std::thread;
+
+struct Worker {
+    id: usize,
+    thread: thread::JoinHandle<()>,
+}
+
+impl Worker {
+    fn new(id: usize) -> Worker {
+        Worker { id, thread: thread::spawn(|| {}) }
+    }
+}
+
+pub struct ThreadPool {
+    workers: Vec<Worker>,
+}
+
+impl ThreadPool {
+    /// Create a new thread pool.
+    ///
+    /// # Panics
+    ///
+    /// - if size is zero
+    pub fn new(size: usize) -> ThreadPool {
+        assert!(size > 0);
+        let mut workers = Vec::with_capacity(size);
+
+        for id in 0..size {
+            workers.push(Worker::new(id));
+        }
+
+        ThreadPool { workers }
+    }
+
+    pub fn execute<F>(&self, f: F)
+    where F: FnOnce() + Send + 'static
+    {
+        thread::spawn(f);
+    }
+}
-- 
2.39.2