【Rust】シングルスレッドとマルチスレッドサーバ

遅いリクエストを実装

use std::thread;
use std::time::Duration;

// 

    let get = b"GET / HTTP/1.1\r\n"; 
    let sleep = b"GET /sleep HTTP/1.1\r\n"; 

    let(status_line, filename) = if buffer.starts_with(get) {
        ("HTTP/1.1 200 OK\r\n\r\n", "hello.html")
    } else if buffer.starts_with(sleep){
        thread::sleep(Duration::from_secs(5));
        ("HTTP/1.1 200 OK\r\n\r\n", "hello.html")
    } else {
        ("HTTP/1.1 404 NOT FOUND\r\n\r\n", "404.html")
    };

### スレッドプール
タスクを処理する準備のできた一塊の大量に生成されたスレッド
ただし、固定された数のスレッドにすることで、無制限に大量生産してDos攻撃の被害に遭うことを抑える。

fn main() {
    let listner = TcpListener::bind("127.0.0.1:7878").unwrap();

    for stream in listner.incoming() {
        let stream = stream.unwrap();

        thread::spawn(||{
            handle_connection(stream);
        });
    }
}

スレッド数を限定する

use std::thread;

pub struct ThreadPool {
    workers: Vec<Worker>,
}

impl ThreadPool {
    pub fn new(size: usize) -> ThreadPool {
        assert!(size > 0);

        let mut threads = Vec::with_capacity(size);

        for _ in 0..size {
            workers.push(Worker::new(id));
        }
        ThreadPool {
            workers
        }
    }

    pub fn execute<F>(&self, f: F)
        where
            F: FnOnce() + Send + 'static
    {

    }
}

struct Worker {
    id: usize,
    thread: thread::JoinHandle<()>,
}

impl Worker {
    fn new(id: usize) -> Worker {
        let thread = thread::spawn(||{});

        Worker {
            id,
            thread,
        }
    }
}

use std::thread;
use std::sync::mpsc;
use std::sync::Arc;
use std::sync::Mutex;

pub struct ThreadPool {
    workers: Vec<Worker>,
    sender: mpsc::Sender<Job>,
}

trait FnBox {
    fn call_box(self: Box<Self>);
}

impl<F: FnOnce()> FnBox for F {
    fn call_box(self: Box<F>){
        (*self)()
    }
}

type Job = Box<dyn FnBox + 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, Arc::clone(&receiver)));
        }
        ThreadPool {
            workers,
            sender,
        }
    }

    pub fn execute<F>(&self, f: F)
        where
            F: FnOnce() + Send + 'static
    {
        let job = Box::new(f);
        self.sender.send(job).unwrap();
    }
}

struct Worker {
    id: usize,
    thread: thread::JoinHandle<()>,
}

impl Worker {
    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.call_box();
            }
        });

        Worker {
            id,
            thread,
        }
    }
}

Worker 0 got a job; executing.
Worker 1 got a job; executing.
Worker 2 got a job; executing.
Worker 3 got a job; executing.
Worker 0 got a job; executing.