ivy.nvim/rust/thread_pool.rs
2022-08-26 10:25:05 +01:00

87 lines
1.8 KiB
Rust

use std::sync::mpsc;
use std::sync::Arc;
use std::sync::Mutex;
use std::thread;
enum Message {
NewJob(Job),
Terminate,
}
pub struct ThreadPool {
jobs: mpsc::Sender<Message>,
threads: Vec<Worker>,
}
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(thread_count: usize) -> Self {
let (jobs, receiver) = mpsc::channel();
let receiver = Arc::new(Mutex::new(receiver));
let mut threads: Vec<Worker> = Vec::new();
for id in 1..thread_count {
threads.push(Worker::new(id, Arc::clone(&receiver)));
}
ThreadPool { jobs, threads }
}
pub fn execute<F>(&self, f: F)
where
F: FnOnce() + Send + 'static,
{
let job = Box::new(f);
self.jobs.send(Message::NewJob(job)).unwrap();
}
}
impl Drop for ThreadPool {
fn drop(&mut self) {
for _ in &mut self.threads {
self.jobs.send(Message::Terminate).unwrap();
}
for worker in &mut self.threads {
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) => job.call_box(),
Message::Terminate => {
break;
}
}
});
Worker {
_id: id,
thread: Some(thread),
}
}
}