use std::{
future::Future,
marker::PhantomData,
mem::ManuallyDrop,
ops,
ptr::NonNull,
task::{RawWaker, RawWakerVTable, Waker},
};
use super::{core::Header, harness::Harness, Schedule};
pub(super) struct WakerRef<'a, S: 'static> {
waker: ManuallyDrop<Waker>,
_p: PhantomData<(&'a Header, S)>,
}
pub(super) fn waker_ref<T, S>(header: &Header) -> WakerRef<'_, S>
where
T: Future,
S: Schedule,
{
let waker = unsafe { ManuallyDrop::new(Waker::from_raw(raw_waker::<T, S>(header))) };
WakerRef {
waker,
_p: PhantomData,
}
}
impl<S> ops::Deref for WakerRef<'_, S> {
type Target = Waker;
fn deref(&self) -> &Waker {
&self.waker
}
}
unsafe fn clone_waker<T, S>(ptr: *const ()) -> RawWaker
where
T: Future,
S: Schedule,
{
let header = ptr as *const Header;
trace!("MONOIO DEBUG[Waker]: clone_waker");
(*header).state.ref_inc();
raw_waker::<T, S>(header)
}
unsafe fn drop_waker<T, S>(ptr: *const ())
where
T: Future,
S: Schedule,
{
let ptr = NonNull::new_unchecked(ptr as *mut Header);
let harness = Harness::<T, S>::from_raw(ptr);
harness.drop_reference();
}
unsafe fn wake_by_val<T, S>(ptr: *const ())
where
T: Future,
S: Schedule,
{
let ptr = NonNull::new_unchecked(ptr as *mut Header);
let harness = Harness::<T, S>::from_raw(ptr);
harness.wake_by_val();
}
unsafe fn wake_by_ref<T, S>(ptr: *const ())
where
T: Future,
S: Schedule,
{
let ptr = NonNull::new_unchecked(ptr as *mut Header);
let harness = Harness::<T, S>::from_raw(ptr);
harness.wake_by_ref();
}
pub(super) fn raw_waker<T, S>(header: *const Header) -> RawWaker
where
T: Future,
S: Schedule,
{
let ptr = header as *const ();
let vtable = &RawWakerVTable::new(
clone_waker::<T, S>,
wake_by_val::<T, S>,
wake_by_ref::<T, S>,
drop_waker::<T, S>,
);
RawWaker::new(ptr, vtable)
}