dope-uring 0.28.0

Owned io_uring backend for dope
Documentation 
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pub(in crate::reactor::ring) mod cleanup;
pub(in crate::reactor::ring) mod closing;
pub(in crate::reactor::ring) mod setups;

use std::{mem, num, ptr};

use dope_sys::{
    io::{Close, Retry},
    kernel,
    ring::create,
};
use o3::mem::Rejected;

use crate::{Mapping, error, reactor::ring};

type Cause = create::Cause<kernel::Errno<error::Setup>, kernel::Errno<error::Map>>;

#[derive(Debug)]
pub(crate) struct Region {
    address: *mut libc::c_void,
    len: num::NonZero<usize>,
}

#[derive(Debug)]
pub(crate) struct Unmap {
    region: Region,
    code: kernel::Errno<error::Unmap>,
}

#[derive(Debug)]
pub(crate) struct Closing(State<Unmap>);
pub(crate) struct Pending(State<Region>);

pub(crate) enum Open {
    Failure(Mapping),
    Cleanup { failure: Mapping, unmap: Unmap },
}

#[derive(Debug)]
pub(crate) struct Set(ring::ffi::Map, ring::ffi::Map);

#[derive(Debug)]
struct State<C> {
    current: C,
    next: Option<ring::ffi::Map>,
}

impl Region {
    pub(crate) const fn new(address: *mut libc::c_void, len: num::NonZero<usize>) -> Self {
        Self { address, len }
    }

    pub(crate) const fn address(&self) -> *mut libc::c_void {
        self.address
    }

    pub(crate) const fn len(&self) -> num::NonZero<usize> {
        self.len
    }
}

impl Close for Region {
    type State = Unmap;

    fn try_close(self) -> Result<(), Unmap> {
        ring::ffi::Map::release(self)
    }
}

impl Unmap {
    pub(crate) const fn new(
        address: *mut libc::c_void,
        len: num::NonZero<usize>,
        code: kernel::Errno<error::Unmap>,
    ) -> Self {
        Self {
            region: Region::new(address, len),
            code,
        }
    }

    pub(crate) const fn failure(&self) -> crate::Unmap {
        crate::Unmap::new(self.region.address, self.region.len, self.code)
    }
}

impl Retry for Unmap {
    type Failure = crate::Unmap;
    type Owner = Region;

    fn recover(self) -> Rejected<Region, crate::Unmap> {
        let failure = self.failure();
        Rejected::new(self.region, failure)
    }
}

impl Closing {
    pub(crate) fn failure(&self) -> crate::Unmap {
        self.0.current.failure()
    }

    pub(crate) fn close(current: ring::ffi::Map, next: Option<ring::ffi::Map>) -> Result<(), Self> {
        Pending(State {
            current: current.into_region(),
            next,
        })
        .try_close()
    }

    pub(crate) const fn dirty(current: Unmap, next: Option<ring::ffi::Map>) -> Self {
        Self(State { current, next })
    }
}

impl Retry for Closing {
    type Failure = crate::Unmap;
    type Owner = Pending;

    fn recover(self) -> Rejected<Pending, crate::Unmap> {
        let State { current, next } = self.0;
        current
            .recover()
            .map(|current| Pending(State { current, next }))
    }
}

impl Close for Pending {
    type State = Closing;

    fn try_close(self) -> Result<(), Closing> {
        let State { current, next } = self.0;
        match current.try_close() {
            Ok(()) => next.map_or(Ok(()), |next| Closing::close(next, None)),
            Err(current) => Err(Closing::dirty(current, next)),
        }
    }
}

impl Set {
    pub(crate) const fn single(submit: ring::ffi::Map, entries: ring::ffi::Map) -> Self {
        Self(submit, entries)
    }

    pub(crate) const fn rings(&self) -> &ring::ffi::Map {
        &self.0
    }

    pub(crate) const fn entries(&self) -> &ring::ffi::Map {
        &self.1
    }

    pub(crate) fn try_close(self) -> Result<(), Closing> {
        let Self(submit, entries) = self;
        Closing::close(entries, Some(submit))
    }
}

const _: () = {
    assert!(mem::size_of::<Set>() == 2 * mem::size_of::<ring::ffi::Map>());
    assert!(mem::align_of::<Set>() == mem::align_of::<ring::ffi::Map>());
    assert!(mem::size_of::<crate::Unmap>() == 3 * mem::size_of::<usize>());
    assert!(mem::align_of::<Unmap>() == mem::align_of::<ptr::NonNull<libc::c_void>>());
};