dope_sys/ring/
enter.rs

1use std::{mem, time};
2
3use crate::kernel;
4
5/// Whether a commit entered the kernel to advance pending work.
6#[derive(Clone, Copy, Debug, Eq, PartialEq)]
7pub enum Progress {
8    Idle,
9    Entered,
10}
11
12/// A duration that cannot be represented by the kernel wait timespec.
13#[derive(Clone, Copy, Debug, Eq, PartialEq)]
14#[repr(transparent)]
15pub struct Overflow(time::Duration);
16
17impl Overflow {
18    pub const fn new(span: time::Duration) -> Self {
19        Self(span)
20    }
21
22    pub const fn requested(self) -> time::Duration {
23        self.0
24    }
25}
26
27/// One affine snapshot of pending submissions and kernel progress flags.
28pub trait Enter: Sized {
29    type Error;
30    type Timeout: TryFrom<time::Duration, Error = Overflow>;
31
32    fn try_submit(self) -> Result<(), Self::Error>;
33    fn try_wait(self, timeout: Option<Self::Timeout>) -> Result<(), Self::Error>;
34    fn try_commit(self) -> Result<Progress, Self::Error>;
35}
36
37/// Exact wait, submit, and cancellation failures retained by a live ring.
38#[derive(Clone, Copy, Debug, Eq, PartialEq)]
39pub enum Poll<E, C> {
40    Timeout { requested: time::Duration },
41    Submit(E),
42    Wait(E),
43    Cancel(C),
44}
45
46impl<E, C> From<Overflow> for Poll<E, C> {
47    fn from(overflow: Overflow) -> Self {
48        Self::Timeout {
49            requested: overflow.requested(),
50        }
51    }
52}
53
54const _: () = {
55    type Failure = Poll<kernel::Errno<()>, kernel::Errno<()>>;
56    assert!(mem::size_of::<Failure>() == mem::size_of::<time::Duration>());
57    assert!(mem::align_of::<Failure>() == mem::align_of::<time::Duration>());
58    assert!(mem::size_of::<Result<(), Failure>>() == mem::size_of::<Failure>());
59};
dope_sys/ring/enter.rs

dope_sys/ring/
enter.rs
