async: rebase wheel on top of async engine

src/async_engine/ae_fd.rs

@@ -146,10 +146,6 @@ impl AsyncFd {
         self.data.fd.raw()
     }
 
-    pub fn eng(&self) -> &Rc<AsyncEngine> {
-        &self.engine
-    }
-
     pub fn readable(&self) -> AsyncFdReadable {
         AsyncFdReadable {
             fd: self,

src/async_engine/ae_timeout.rs

@@ -1,51 +0,0 @@
-use {
-    crate::wheel::{Wheel, WheelDispatcher, WheelId},
-    std::{
-        cell::{Cell, RefCell},
-        error::Error,
-        future::Future,
-        pin::Pin,
-        rc::Rc,
-        task::{Context, Poll, Waker},
-    },
-};
-
-pub(super) struct TimeoutData {
-    pub expired: Cell<bool>,
-    pub waker: RefCell<Option<Waker>>,
-}
-
-impl WheelDispatcher for TimeoutData {
-    fn dispatch(self: Rc<Self>) -> Result<(), Box<dyn Error>> {
-        self.expired.set(true);
-        if let Some(w) = self.waker.borrow_mut().take() {
-            w.wake();
-        }
-        Ok(())
-    }
-}
-
-pub struct Timeout {
-    pub(super) id: WheelId,
-    pub(super) wheel: Rc<Wheel>,
-    pub(super) data: Rc<TimeoutData>,
-}
-
-impl Future for Timeout {
-    type Output = ();
-
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        if self.data.expired.get() {
-            Poll::Ready(())
-        } else {
-            *self.data.waker.borrow_mut() = Some(cx.waker().clone());
-            Poll::Pending
-        }
-    }
-}
-
-impl Drop for Timeout {
-    fn drop(&mut self) {
-        self.wheel.remove(self.id);
-    }
-}