use core::cell::Cell;
use core::marker::Unpin;
-use core::mem::PinMut;
+use core::pin::Pin;
use core::option::Option;
use core::ptr::NonNull;
-use core::task::{self, Poll};
+use core::task::{LocalWaker, Poll};
use core::ops::{Drop, Generator, GeneratorState};
#[doc(inline)]
#[unstable(feature = "gen_future", issue = "50547")]
impl<T: Generator<Yield = ()>> Future for GenFuture<T> {
type Output = T::Return;
- fn poll(self: PinMut<Self>, cx: &mut task::Context) -> Poll<Self::Output> {
- set_task_cx(cx, || match unsafe { PinMut::get_mut_unchecked(self).0.resume() } {
+ fn poll(self: Pin<&mut Self>, lw: &LocalWaker) -> Poll<Self::Output> {
+ set_task_waker(lw, || match unsafe { Pin::get_mut_unchecked(self).0.resume() } {
GeneratorState::Yielded(()) => Poll::Pending,
GeneratorState::Complete(x) => Poll::Ready(x),
})
}
thread_local! {
- static TLS_CX: Cell<Option<NonNull<task::Context<'static>>>> = Cell::new(None);
+ static TLS_WAKER: Cell<Option<NonNull<LocalWaker>>> = Cell::new(None);
}
-struct SetOnDrop(Option<NonNull<task::Context<'static>>>);
+struct SetOnDrop(Option<NonNull<LocalWaker>>);
impl Drop for SetOnDrop {
fn drop(&mut self) {
- TLS_CX.with(|tls_cx| {
- tls_cx.set(self.0.take());
+ TLS_WAKER.with(|tls_waker| {
+ tls_waker.set(self.0.take());
});
}
}
#[unstable(feature = "gen_future", issue = "50547")]
/// Sets the thread-local task context used by async/await futures.
-pub fn set_task_cx<F, R>(cx: &mut task::Context, f: F) -> R
+pub fn set_task_waker<F, R>(lw: &LocalWaker, f: F) -> R
where
F: FnOnce() -> R
{
- let old_cx = TLS_CX.with(|tls_cx| {
- tls_cx.replace(NonNull::new(
- cx
- as *mut task::Context
- as *mut ()
- as *mut task::Context<'static>
- ))
+ let old_waker = TLS_WAKER.with(|tls_waker| {
+ tls_waker.replace(Some(NonNull::from(lw)))
});
- let _reset_cx = SetOnDrop(old_cx);
+ let _reset_waker = SetOnDrop(old_waker);
f()
}
#[unstable(feature = "gen_future", issue = "50547")]
-/// Retrieves the thread-local task context used by async/await futures.
+/// Retrieves the thread-local task waker used by async/await futures.
///
-/// This function acquires exclusive access to the task context.
+/// This function acquires exclusive access to the task waker.
///
-/// Panics if no task has been set or if the task context has already been
-/// retrieved by a surrounding call to get_task_cx.
-pub fn get_task_cx<F, R>(f: F) -> R
+/// Panics if no waker has been set or if the waker has already been
+/// retrieved by a surrounding call to get_task_waker.
+pub fn get_task_waker<F, R>(f: F) -> R
where
- F: FnOnce(&mut task::Context) -> R
+ F: FnOnce(&LocalWaker) -> R
{
- let cx_ptr = TLS_CX.with(|tls_cx| {
- // Clear the entry so that nested `with_get_cx` calls
+ let waker_ptr = TLS_WAKER.with(|tls_waker| {
+ // Clear the entry so that nested `get_task_waker` calls
// will fail or set their own value.
- tls_cx.replace(None)
+ tls_waker.replace(None)
});
- let _reset_cx = SetOnDrop(cx_ptr);
+ let _reset_waker = SetOnDrop(waker_ptr);
- let mut cx_ptr = cx_ptr.expect(
- "TLS task::Context not set. This is a rustc bug. \
+ let mut waker_ptr = waker_ptr.expect(
+ "TLS LocalWaker not set. This is a rustc bug. \
Please file an issue on https://github.com/rust-lang/rust.");
- unsafe { f(cx_ptr.as_mut()) }
+ unsafe { f(waker_ptr.as_mut()) }
}
#[unstable(feature = "gen_future", issue = "50547")]
-/// Polls a future in the current thread-local task context.
-pub fn poll_in_task_cx<F>(f: PinMut<F>) -> Poll<F::Output>
+/// Polls a future in the current thread-local task waker.
+pub fn poll_with_tls_waker<F>(f: Pin<&mut F>) -> Poll<F::Output>
where
F: Future
{
- get_task_cx(|cx| f.poll(cx))
+ get_task_waker(|lw| F::poll(f, lw))
}