blob: f87f11818518347fa0057d17ae9d9e8caf351e98 [file] [log] [blame]
use std::prelude::v1::*;
use std::any::Any;
use std::panic::{catch_unwind, UnwindSafe, AssertUnwindSafe};
use {Future, Poll, Async};
/// Future for the `catch_unwind` combinator.
///
/// This is created by the `Future::catch_unwind` method.
#[derive(Debug)]
#[must_use = "futures do nothing unless polled"]
pub struct CatchUnwind<F> where F: Future {
future: Option<F>,
}
pub fn new<F>(future: F) -> CatchUnwind<F>
where F: Future + UnwindSafe,
{
CatchUnwind {
future: Some(future),
}
}
impl<F> Future for CatchUnwind<F>
where F: Future + UnwindSafe,
{
type Item = Result<F::Item, F::Error>;
type Error = Box<Any + Send>;
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
let mut future = self.future.take().expect("cannot poll twice");
let (res, future) = catch_unwind(|| (future.poll(), future))?;
match res {
Ok(Async::NotReady) => {
self.future = Some(future);
Ok(Async::NotReady)
}
Ok(Async::Ready(t)) => Ok(Async::Ready(Ok(t))),
Err(e) => Ok(Async::Ready(Err(e))),
}
}
}
impl<F: Future> Future for AssertUnwindSafe<F> {
type Item = F::Item;
type Error = F::Error;
fn poll(&mut self) -> Poll<F::Item, F::Error> {
self.0.poll()
}
}