vesys-bank-server/socket-server/src/threadpool.rs

95 lines
2.0 KiB
Rust

use std::sync::mpsc;
use std::sync::Arc;
use std::sync::Mutex;
use std::thread;
pub struct ThreadPool {
workers: Vec<Worker>,
sender: mpsc::Sender<Message>,
}
type Job = Box<dyn FnOnce() + Send + 'static>;
enum Message {
NewJob(Job),
Terminate,
}
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(Message::NewJob(job)).unwrap();
}
}
impl Drop for ThreadPool {
fn drop(&mut self) {
trace!("Sending terminate message to all workers.");
for _ in &self.workers {
self.sender.send(Message::Terminate).unwrap();
}
trace!("Shutting down all workers.");
for worker in &mut self.workers {
trace!("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 {
fn new(id: usize, receiver: Arc<Mutex<mpsc::Receiver<Message>>>) -> Worker {
let thread = thread::spawn(move || loop {
let message = receiver.lock().unwrap().recv().unwrap();
match message {
Message::NewJob(job) => {
trace!("Worker {} got a job; executing.", id);
job();
}
Message::Terminate => {
trace!("Worker {} was told to terminate.", id);
break;
}
}
});
Worker {
id,
thread: Some(thread),
}
}
}