vendor/tokio-threadpool/src/park/boxed.rs

use tokio_executor::park::{Park, Unpark};

use std::error::Error;
use std::time::Duration;

pub(crate) type BoxPark = Box<Park<Unpark = BoxUnpark, Error = ()> + Send>;
pub(crate) type BoxUnpark = Box<Unpark>;

pub(crate) struct BoxedPark<T>(T);

impl<T> BoxedPark<T> {
    pub fn new(inner: T) -> Self {
        BoxedPark(inner)
    }
}

impl<T: Park + Send> Park for BoxedPark<T>
where T::Error: Error,
{
    type Unpark = BoxUnpark;
    type Error = ();

    fn unpark(&self) -> Self::Unpark {
        Box::new(self.0.unpark())
    }

    fn park(&mut self) -> Result<(), Self::Error> {
        self.0.park()
            .map_err(|e| {
                warn!("calling `park` on worker thread errored -- shutting down thread: {}", e);
            })
    }

    fn park_timeout(&mut self, duration: Duration) -> Result<(), Self::Error> {
        self.0.park_timeout(duration)
            .map_err(|e| {
                warn!("calling `park` on worker thread errored -- shutting down thread: {}", e);
            })
    }
}