chore: checkpoint before Python removal

vendor/mio/src/sys/mod.rs

@@ -0,0 +1,147 @@
+//! Module with system specific types.
+//!
+//! Required types:
+//!
+//! * `Event`: a type alias for the system specific event, e.g. `kevent` or
+//!   `epoll_event`.
+//! * `event`: a module with various helper functions for `Event`, see
+//!   [`crate::event::Event`] for the required functions.
+//! * `Events`: collection of `Event`s, see [`crate::Events`].
+//! * `IoSourceState`: state for the `IoSource` type.
+//! * `Selector`: selector used to register event sources and poll for events,
+//!   see [`crate::Poll`] and [`crate::Registry`] for required methods.
+//! * `tcp` and `udp` modules: see the [`crate::net`] module.
+//! * `Waker`: see [`crate::Waker`].
+
+cfg_os_poll! {
+    macro_rules! debug_detail {
+        (
+            $type: ident ($event_type: ty), $test: path,
+            $($(#[$target: meta])* $libc: ident :: $flag: ident),+ $(,)*
+        ) => {
+            struct $type($event_type);
+
+            impl fmt::Debug for $type {
+                fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+                    let mut written_one = false;
+                    $(
+                        $(#[$target])*
+                        #[allow(clippy::bad_bit_mask)] // Apparently some flags are zero.
+                        {
+                            // Windows doesn't use `libc` but the `afd` module.
+                            if $test(&self.0, &$libc :: $flag) {
+                                if !written_one {
+                                    write!(f, "{}", stringify!($flag))?;
+                                    written_one = true;
+                                } else {
+                                    write!(f, "|{}", stringify!($flag))?;
+                                }
+                            }
+                        }
+                    )+
+                    if !written_one {
+                        write!(f, "(empty)")
+                    } else {
+                        Ok(())
+                    }
+                }
+            }
+        };
+    }
+}
+
+#[cfg(any(unix, target_os = "hermit"))]
+cfg_os_poll! {
+    mod unix;
+    #[allow(unused_imports)]
+    pub use self::unix::*;
+}
+
+#[cfg(windows)]
+cfg_os_poll! {
+    mod windows;
+    pub use self::windows::*;
+}
+
+#[cfg(target_os = "wasi")]
+cfg_os_poll! {
+    mod wasi;
+    pub(crate) use self::wasi::*;
+}
+
+cfg_not_os_poll! {
+    mod shell;
+    pub(crate) use self::shell::*;
+
+    #[cfg(unix)]
+    cfg_any_os_ext! {
+        mod unix;
+        #[cfg(feature = "os-ext")]
+        pub use self::unix::SourceFd;
+    }
+}
+
+/// Define the `listen` backlog parameters as in the standard library. This
+/// helps avoid hardcoded unsynchronized values and allows better control of
+/// default values depending on the target.
+///
+/// Selecting a “valid” default value can be tricky due to:
+///
+/// - It often serves only as a hint and may be rounded, trimmed, or ignored by
+///   the OS.
+///
+/// - It is sometimes provided as a "magic" value, for example, -1. This
+///   value is undocumented and not standard, but it is often used to represent
+///   the largest possible backlog size. This happens due to signed/unsigned
+///   conversion and rounding to the upper bound performed by the OS.
+///
+/// - Default values vary depending on the OS and its version. Common defaults
+///   include: -1, 128, 1024, and 4096.
+///
+// Here is the original code from the standard library
+// https://github.com/rust-lang/rust/blob/4f808ba6bf9f1c8dde30d009e73386d984491587/library/std/src/os/unix/net/listener.rs#L72
+//
+#[allow(dead_code)]
+#[cfg(any(
+    target_os = "windows",
+    target_os = "redox",
+    target_os = "espidf",
+    target_os = "horizon"
+))]
+pub(crate) const LISTEN_BACKLOG_SIZE: i32 = 128;
+
+/// This is a special case for some target(s) supported by `mio`.  This value
+/// is needed because `libc::SOMAXCON` (used as a fallback for unknown targets)
+/// is not implemented for them. Feel free to update this if the `libc` crate
+/// changes.
+#[allow(dead_code)]
+#[cfg(target_os = "hermit")]
+pub(crate) const LISTEN_BACKLOG_SIZE: i32 = 1024;
+
+#[allow(dead_code)]
+#[cfg(any(
+    // Silently capped to `/proc/sys/net/core/somaxconn`.
+    target_os = "linux",
+    // Silently capped to `kern.ipc.soacceptqueue`.
+    target_os = "freebsd",
+    // Silently capped to `kern.somaxconn sysctl`.
+    target_os = "openbsd",
+    // Silently capped to the default 128.
+    target_vendor = "apple",
+))]
+pub(crate) const LISTEN_BACKLOG_SIZE: i32 = -1;
+
+#[allow(dead_code)]
+#[cfg(not(any(
+    target_os = "windows",
+    target_os = "redox",
+    target_os = "espidf",
+    target_os = "horizon",
+    target_os = "linux",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "wasi",
+    target_os = "hermit",
+    target_vendor = "apple",
+)))]
+pub(crate) const LISTEN_BACKLOG_SIZE: i32 = libc::SOMAXCONN;

vendor/mio/src/sys/shell/mod.rs

@@ -0,0 +1,105 @@
+macro_rules! os_required {
+    () => {
+        panic!("mio must be compiled with `os-poll` to run.")
+    };
+}
+
+mod selector;
+pub(crate) use self::selector::{event, Event, Events, Selector};
+
+#[cfg(not(target_os = "wasi"))]
+mod waker;
+#[cfg(not(target_os = "wasi"))]
+pub(crate) use self::waker::Waker;
+
+cfg_net! {
+    pub(crate) mod tcp;
+    pub(crate) mod udp;
+    #[cfg(unix)]
+    pub(crate) mod uds;
+}
+
+cfg_io_source! {
+    use std::io;
+    #[cfg(any(unix))]
+    use std::os::fd::RawFd;
+    // TODO: once <https://github.com/rust-lang/rust/issues/126198> is fixed this
+    // can use `std::os::fd` and be merged with the above.
+    #[cfg(target_os = "hermit")]
+    use std::os::hermit::io::RawFd;
+    #[cfg(windows)]
+    use std::os::windows::io::RawSocket;
+
+    #[cfg(any(windows, unix, target_os = "hermit"))]
+    use crate::{Registry, Token, Interest};
+
+    pub(crate) struct IoSourceState;
+
+    impl IoSourceState {
+        pub fn new() -> IoSourceState {
+            IoSourceState
+        }
+
+        pub fn do_io<T, F, R>(&self, f: F, io: &T) -> io::Result<R>
+        where
+            F: FnOnce(&T) -> io::Result<R>,
+        {
+            // We don't hold state, so we can just call the function and
+            // return.
+            f(io)
+        }
+    }
+
+    #[cfg(any(unix, target_os = "hermit"))]
+    impl IoSourceState {
+        pub fn register(
+            &mut self,
+            _: &Registry,
+            _: Token,
+            _: Interest,
+            _: RawFd,
+        ) -> io::Result<()> {
+            os_required!()
+        }
+
+        pub fn reregister(
+            &mut self,
+            _: &Registry,
+            _: Token,
+            _: Interest,
+            _: RawFd,
+        ) -> io::Result<()> {
+           os_required!()
+        }
+
+        pub fn deregister(&mut self, _: &Registry, _: RawFd) -> io::Result<()> {
+            os_required!()
+        }
+    }
+
+    #[cfg(windows)]
+    impl IoSourceState {
+         pub fn register(
+            &mut self,
+            _: &Registry,
+            _: Token,
+            _: Interest,
+            _: RawSocket,
+        ) -> io::Result<()> {
+            os_required!()
+        }
+
+        pub fn reregister(
+            &mut self,
+            _: &Registry,
+            _: Token,
+            _: Interest,
+        ) -> io::Result<()> {
+           os_required!()
+        }
+
+        pub fn deregister(&mut self) -> io::Result<()> {
+            os_required!()
+        }
+    }
+}

vendor/mio/src/sys/shell/selector.rs

@@ -0,0 +1,122 @@
+use std::io;
+#[cfg(unix)]
+use std::os::fd::{AsRawFd, RawFd};
+use std::time::Duration;
+
+pub type Event = usize;
+
+pub type Events = Vec<Event>;
+
+#[derive(Debug)]
+pub struct Selector {}
+
+impl Selector {
+    pub fn try_clone(&self) -> io::Result<Selector> {
+        os_required!();
+    }
+
+    pub fn select(&self, _: &mut Events, _: Option<Duration>) -> io::Result<()> {
+        os_required!();
+    }
+}
+
+#[cfg(unix)]
+cfg_os_ext! {
+    use crate::{Interest, Token};
+
+    impl Selector {
+        pub fn register(&self, _: RawFd, _: Token, _: Interest) -> io::Result<()> {
+            os_required!();
+        }
+
+        pub fn reregister(&self, _: RawFd, _: Token, _: Interest) -> io::Result<()> {
+            os_required!();
+        }
+
+        pub fn deregister(&self, _: RawFd) -> io::Result<()> {
+            os_required!();
+        }
+    }
+}
+
+#[cfg(target_os = "wasi")]
+cfg_any_os_ext! {
+    use crate::{Interest, Token};
+
+    impl Selector {
+        pub fn register(&self, _: wasi::Fd, _: Token, _: Interest) -> io::Result<()> {
+            os_required!();
+        }
+
+        pub fn reregister(&self, _: wasi::Fd, _: Token, _: Interest) -> io::Result<()> {
+            os_required!();
+        }
+
+        pub fn deregister(&self, _: wasi::Fd) -> io::Result<()> {
+            os_required!();
+        }
+    }
+}
+
+cfg_io_source! {
+    #[cfg(debug_assertions)]
+    impl Selector {
+        pub fn id(&self) -> usize {
+            os_required!();
+        }
+    }
+}
+
+#[cfg(unix)]
+impl AsRawFd for Selector {
+    fn as_raw_fd(&self) -> RawFd {
+        os_required!()
+    }
+}
+
+#[allow(clippy::trivially_copy_pass_by_ref)]
+pub mod event {
+    use crate::sys::Event;
+    use crate::Token;
+    use std::fmt;
+
+    pub fn token(_: &Event) -> Token {
+        os_required!();
+    }
+
+    pub fn is_readable(_: &Event) -> bool {
+        os_required!();
+    }
+
+    pub fn is_writable(_: &Event) -> bool {
+        os_required!();
+    }
+
+    pub fn is_error(_: &Event) -> bool {
+        os_required!();
+    }
+
+    pub fn is_read_closed(_: &Event) -> bool {
+        os_required!();
+    }
+
+    pub fn is_write_closed(_: &Event) -> bool {
+        os_required!();
+    }
+
+    pub fn is_priority(_: &Event) -> bool {
+        os_required!();
+    }
+
+    pub fn is_aio(_: &Event) -> bool {
+        os_required!();
+    }
+
+    pub fn is_lio(_: &Event) -> bool {
+        os_required!();
+    }
+
+    pub fn debug_details(_: &mut fmt::Formatter<'_>, _: &Event) -> fmt::Result {
+        os_required!();
+    }
+}

vendor/mio/src/sys/shell/tcp.rs

@@ -0,0 +1,31 @@
+use std::io;
+use std::net::{self, SocketAddr};
+
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn new_for_addr(_: SocketAddr) -> io::Result<i32> {
+    os_required!();
+}
+
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn bind(_: &net::TcpListener, _: SocketAddr) -> io::Result<()> {
+    os_required!();
+}
+
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn connect(_: &net::TcpStream, _: SocketAddr) -> io::Result<()> {
+    os_required!();
+}
+
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn listen(_: &net::TcpListener, _: i32) -> io::Result<()> {
+    os_required!();
+}
+
+#[cfg(any(unix, target_os = "hermit"))]
+pub(crate) fn set_reuseaddr(_: &net::TcpListener, _: bool) -> io::Result<()> {
+    os_required!();
+}
+
+pub(crate) fn accept(_: &net::TcpListener) -> io::Result<(net::TcpStream, SocketAddr)> {
+    os_required!();
+}

vendor/mio/src/sys/shell/udp.rs

@@ -0,0 +1,11 @@
+#![cfg(not(target_os = "wasi"))]
+use std::io;
+use std::net::{self, SocketAddr};
+
+pub fn bind(_: SocketAddr) -> io::Result<net::UdpSocket> {
+    os_required!()
+}
+
+pub(crate) fn only_v6(_: &net::UdpSocket) -> io::Result<bool> {
+    os_required!()
+}

vendor/mio/src/sys/shell/uds.rs

@@ -0,0 +1,44 @@
+pub(crate) mod datagram {
+    use std::io;
+    use std::os::unix::net::{self, SocketAddr};
+
+    pub(crate) fn bind_addr(_: &SocketAddr) -> io::Result<net::UnixDatagram> {
+        os_required!()
+    }
+
+    pub(crate) fn unbound() -> io::Result<net::UnixDatagram> {
+        os_required!()
+    }
+
+    pub(crate) fn pair() -> io::Result<(net::UnixDatagram, net::UnixDatagram)> {
+        os_required!()
+    }
+}
+
+pub(crate) mod listener {
+    use std::io;
+    use std::os::unix::net::{self, SocketAddr};
+
+    use crate::net::UnixStream;
+
+    pub(crate) fn bind_addr(_: &SocketAddr) -> io::Result<net::UnixListener> {
+        os_required!()
+    }
+
+    pub(crate) fn accept(_: &net::UnixListener) -> io::Result<(UnixStream, SocketAddr)> {
+        os_required!()
+    }
+}
+
+pub(crate) mod stream {
+    use std::io;
+    use std::os::unix::net::{self, SocketAddr};
+
+    pub(crate) fn connect_addr(_: &SocketAddr) -> io::Result<net::UnixStream> {
+        os_required!()
+    }
+
+    pub(crate) fn pair() -> io::Result<(net::UnixStream, net::UnixStream)> {
+        os_required!()
+    }
+}

vendor/mio/src/sys/shell/waker.rs

@@ -0,0 +1,16 @@
+use crate::sys::Selector;
+use crate::Token;
+use std::io;
+
+#[derive(Debug)]
+pub struct Waker {}
+
+impl Waker {
+    pub fn new(_: &Selector, _: Token) -> io::Result<Waker> {
+        os_required!();
+    }
+
+    pub fn wake(&self) -> io::Result<()> {
+        os_required!();
+    }
+}

vendor/mio/src/sys/unix/mod.rs

@@ -0,0 +1,167 @@
+/// Helper macro to execute a system call that returns an `io::Result`.
+//
+// Macro must be defined before any modules that uses them.
+#[allow(unused_macros)]
+macro_rules! syscall {
+    ($fn: ident ( $($arg: expr),* $(,)* ) ) => {{
+        #[allow(unused_unsafe)]
+        let res = unsafe { libc::$fn($($arg, )*) };
+        if res < 0 {
+            Err(std::io::Error::last_os_error())
+        } else {
+            Ok(res)
+        }
+    }};
+}
+
+cfg_os_poll! {
+    #[cfg_attr(all(
+        not(mio_unsupported_force_poll_poll),
+        any(
+            target_os = "android",
+            target_os = "illumos",
+            target_os = "linux",
+            target_os = "redox",
+        )
+    ), path = "selector/epoll.rs")]
+    #[cfg_attr(all(
+        not(mio_unsupported_force_poll_poll),
+        any(
+            target_os = "dragonfly",
+            target_os = "freebsd",
+            target_os = "ios",
+            target_os = "macos",
+            target_os = "netbsd",
+            target_os = "openbsd",
+            target_os = "tvos",
+            target_os = "visionos",
+            target_os = "watchos",
+        )
+    ), path = "selector/kqueue.rs")]
+    #[cfg_attr(any(
+        mio_unsupported_force_poll_poll,
+        target_os = "aix",
+        target_os = "espidf",
+        target_os = "fuchsia",
+        target_os = "haiku",
+        target_os = "hermit",
+        target_os = "hurd",
+        target_os = "nto",
+        target_os = "solaris",
+        target_os = "vita",
+        target_os = "cygwin",
+    ), path = "selector/poll.rs")]
+    mod selector;
+    pub(crate) use self::selector::*;
+
+    #[cfg_attr(all(
+        not(mio_unsupported_force_waker_pipe),
+        any(
+            target_os = "android",
+            target_os = "espidf",
+            target_os = "fuchsia",
+            target_os = "hermit",
+            target_os = "illumos",
+            target_os = "linux",
+        )
+    ), path = "waker/eventfd.rs")]
+    #[cfg_attr(all(
+        not(mio_unsupported_force_waker_pipe),
+        not(mio_unsupported_force_poll_poll), // `kqueue(2)` based waker doesn't work with `poll(2)`.
+        any(
+            target_os = "freebsd",
+            target_os = "ios",
+            target_os = "macos",
+            target_os = "tvos",
+            target_os = "visionos",
+            target_os = "watchos",
+        )
+    ), path = "waker/kqueue.rs")]
+    #[cfg_attr(any(
+        // NOTE: also add to the list for the `pipe` module below.
+        mio_unsupported_force_waker_pipe,
+        all(
+            // `kqueue(2)` based waker doesn't work with `poll(2)`.
+            mio_unsupported_force_poll_poll,
+            any(
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ),
+        ),
+        target_os = "aix",
+        target_os = "dragonfly",
+        target_os = "haiku",
+        target_os = "hurd",
+        target_os = "netbsd",
+        target_os = "nto",
+        target_os = "openbsd",
+        target_os = "redox",
+        target_os = "solaris",
+        target_os = "vita",
+        target_os = "cygwin",
+    ), path = "waker/pipe.rs")]
+    mod waker;
+    // NOTE: the `Waker` type is expected in the selector module as the
+    // `poll(2)` implementation needs to do some special stuff.
+
+    #[cfg(feature = "os-ext")]
+    mod sourcefd;
+    #[cfg(feature = "os-ext")]
+    pub use self::sourcefd::SourceFd;
+
+    cfg_net! {
+        mod net;
+
+        pub(crate) mod tcp;
+        pub(crate) mod udp;
+        #[cfg(not(target_os = "hermit"))]
+        pub(crate) mod uds;
+    }
+
+    #[cfg(all(
+        any(
+            // For the public `pipe` module, must match `cfg_os_ext` macro.
+            feature = "os-ext",
+            // For the `Waker` type based on a pipe.
+            mio_unsupported_force_waker_pipe,
+            all(
+                // `kqueue(2)` based waker doesn't work with `poll(2)`.
+                mio_unsupported_force_poll_poll,
+                any(
+                    target_os = "freebsd",
+                    target_os = "ios",
+                    target_os = "macos",
+                    target_os = "tvos",
+                    target_os = "visionos",
+                    target_os = "watchos",
+                ),
+            ),
+            // NOTE: also add to the list for the `pipe` module below.
+            target_os = "aix",
+            target_os = "dragonfly",
+            target_os = "haiku",
+            target_os = "hurd",
+            target_os = "netbsd",
+            target_os = "nto",
+            target_os = "openbsd",
+            target_os = "redox",
+            target_os = "solaris",
+            target_os = "vita",
+            target_os = "cygwin",
+        ),
+        // Hermit doesn't support pipes.
+        not(target_os = "hermit"),
+    ))]
+    pub(crate) mod pipe;
+}
+
+cfg_not_os_poll! {
+    cfg_os_ext! {
+        mod sourcefd;
+        pub use self::sourcefd::SourceFd;
+    }
+}

vendor/mio/src/sys/unix/net.rs

@@ -0,0 +1,216 @@
+use std::io;
+use std::mem::size_of;
+use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
+
+pub(crate) fn new_ip_socket(addr: SocketAddr, socket_type: libc::c_int) -> io::Result<libc::c_int> {
+    let domain = match addr {
+        SocketAddr::V4(..) => libc::AF_INET,
+        SocketAddr::V6(..) => libc::AF_INET6,
+    };
+
+    new_socket(domain, socket_type)
+}
+
+/// Create a new non-blocking socket.
+pub(crate) fn new_socket(domain: libc::c_int, socket_type: libc::c_int) -> io::Result<libc::c_int> {
+    #[cfg(any(
+        target_os = "android",
+        target_os = "dragonfly",
+        target_os = "freebsd",
+        target_os = "hurd",
+        target_os = "illumos",
+        target_os = "linux",
+        target_os = "netbsd",
+        target_os = "openbsd",
+        target_os = "solaris",
+        target_os = "hermit",
+        target_os = "cygwin",
+    ))]
+    let socket_type = socket_type | libc::SOCK_NONBLOCK | libc::SOCK_CLOEXEC;
+    #[cfg(target_os = "nto")]
+    let socket_type = socket_type | libc::SOCK_CLOEXEC;
+
+    let socket = syscall!(socket(domain, socket_type, 0))?;
+
+    // Mimic `libstd` and set `SO_NOSIGPIPE` on apple systems.
+    #[cfg(any(
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos",
+    ))]
+    if let Err(err) = syscall!(setsockopt(
+        socket,
+        libc::SOL_SOCKET,
+        libc::SO_NOSIGPIPE,
+        &1 as *const libc::c_int as *const libc::c_void,
+        size_of::<libc::c_int>() as libc::socklen_t
+    )) {
+        let _ = syscall!(close(socket));
+        return Err(err);
+    }
+
+    // Darwin (and others) doesn't have SOCK_NONBLOCK or SOCK_CLOEXEC.
+    #[cfg(any(
+        target_os = "aix",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos",
+        target_os = "espidf",
+        target_os = "vita",
+        target_os = "nto",
+    ))]
+    {
+        if let Err(err) = syscall!(fcntl(socket, libc::F_SETFL, libc::O_NONBLOCK)) {
+            let _ = syscall!(close(socket));
+            return Err(err);
+        }
+        #[cfg(not(any(target_os = "espidf", target_os = "vita", target_os = "nto")))]
+        if let Err(err) = syscall!(fcntl(socket, libc::F_SETFD, libc::FD_CLOEXEC)) {
+            let _ = syscall!(close(socket));
+            return Err(err);
+        }
+    }
+
+    Ok(socket)
+}
+
+/// A type with the same memory layout as `libc::sockaddr`. Used in converting Rust level
+/// SocketAddr* types into their system representation. The benefit of this specific
+/// type over using `libc::sockaddr_storage` is that this type is exactly as large as it
+/// needs to be and not a lot larger. And it can be initialized cleaner from Rust.
+#[repr(C)]
+pub(crate) union SocketAddrCRepr {
+    v4: libc::sockaddr_in,
+    v6: libc::sockaddr_in6,
+}
+
+impl SocketAddrCRepr {
+    pub(crate) fn as_ptr(&self) -> *const libc::sockaddr {
+        self as *const _ as *const libc::sockaddr
+    }
+}
+
+/// Converts a Rust `SocketAddr` into the system representation.
+pub(crate) fn socket_addr(addr: &SocketAddr) -> (SocketAddrCRepr, libc::socklen_t) {
+    match addr {
+        SocketAddr::V4(ref addr) => {
+            // `s_addr` is stored as BE on all machine and the array is in BE order.
+            // So the native endian conversion method is used so that it's never swapped.
+            let sin_addr = libc::in_addr {
+                s_addr: u32::from_ne_bytes(addr.ip().octets()),
+            };
+
+            let sockaddr_in = libc::sockaddr_in {
+                sin_family: libc::AF_INET as libc::sa_family_t,
+                sin_port: addr.port().to_be(),
+                sin_addr,
+                #[cfg(not(any(target_os = "haiku", target_os = "vita")))]
+                sin_zero: [0; 8],
+                #[cfg(target_os = "haiku")]
+                sin_zero: [0; 24],
+                #[cfg(target_os = "vita")]
+                sin_zero: [0; 6],
+                #[cfg(any(
+                    target_os = "aix",
+                    target_os = "dragonfly",
+                    target_os = "freebsd",
+                    target_os = "haiku",
+                    target_os = "hurd",
+                    target_os = "ios",
+                    target_os = "macos",
+                    target_os = "netbsd",
+                    target_os = "openbsd",
+                    target_os = "tvos",
+                    target_os = "visionos",
+                    target_os = "watchos",
+                    target_os = "espidf",
+                    target_os = "vita",
+                    target_os = "hermit",
+                    target_os = "nto",
+                ))]
+                sin_len: 0,
+                #[cfg(target_os = "vita")]
+                sin_vport: addr.port().to_be(),
+            };
+
+            let sockaddr = SocketAddrCRepr { v4: sockaddr_in };
+            let socklen = size_of::<libc::sockaddr_in>() as libc::socklen_t;
+            (sockaddr, socklen)
+        }
+        SocketAddr::V6(ref addr) => {
+            let sockaddr_in6 = libc::sockaddr_in6 {
+                sin6_family: libc::AF_INET6 as libc::sa_family_t,
+                sin6_port: addr.port().to_be(),
+                sin6_addr: libc::in6_addr {
+                    s6_addr: addr.ip().octets(),
+                },
+                sin6_flowinfo: addr.flowinfo(),
+                sin6_scope_id: addr.scope_id(),
+                #[cfg(any(
+                    target_os = "aix",
+                    target_os = "dragonfly",
+                    target_os = "freebsd",
+                    target_os = "haiku",
+                    target_os = "hurd",
+                    target_os = "ios",
+                    target_os = "macos",
+                    target_os = "netbsd",
+                    target_os = "openbsd",
+                    target_os = "tvos",
+                    target_os = "visionos",
+                    target_os = "watchos",
+                    target_os = "espidf",
+                    target_os = "vita",
+                    target_os = "nto",
+                    target_os = "hermit",
+                ))]
+                sin6_len: 0,
+                #[cfg(target_os = "vita")]
+                sin6_vport: addr.port().to_be(),
+                #[cfg(any(target_os = "illumos", target_os = "solaris"))]
+                __sin6_src_id: 0,
+            };
+
+            let sockaddr = SocketAddrCRepr { v6: sockaddr_in6 };
+            let socklen = size_of::<libc::sockaddr_in6>() as libc::socklen_t;
+            (sockaddr, socklen)
+        }
+    }
+}
+
+/// Converts a `libc::sockaddr` compatible struct into a native Rust `SocketAddr`.
+///
+/// # Safety
+///
+/// `storage` must have the `ss_family` field correctly initialized.
+/// `storage` must be initialised to a `sockaddr_in` or `sockaddr_in6`.
+pub(crate) unsafe fn to_socket_addr(
+    storage: *const libc::sockaddr_storage,
+) -> io::Result<SocketAddr> {
+    match (*storage).ss_family as libc::c_int {
+        libc::AF_INET => {
+            // Safety: if the ss_family field is AF_INET then storage must be a sockaddr_in.
+            let addr: &libc::sockaddr_in = &*(storage as *const libc::sockaddr_in);
+            let ip = Ipv4Addr::from(addr.sin_addr.s_addr.to_ne_bytes());
+            let port = u16::from_be(addr.sin_port);
+            Ok(SocketAddr::V4(SocketAddrV4::new(ip, port)))
+        }
+        libc::AF_INET6 => {
+            // Safety: if the ss_family field is AF_INET6 then storage must be a sockaddr_in6.
+            let addr: &libc::sockaddr_in6 = &*(storage as *const libc::sockaddr_in6);
+            let ip = Ipv6Addr::from(addr.sin6_addr.s6_addr);
+            let port = u16::from_be(addr.sin6_port);
+            Ok(SocketAddr::V6(SocketAddrV6::new(
+                ip,
+                port,
+                addr.sin6_flowinfo,
+                addr.sin6_scope_id,
+            )))
+        }
+        _ => Err(io::ErrorKind::InvalidInput.into()),
+    }
+}

vendor/mio/src/sys/unix/pipe.rs

@@ -0,0 +1,620 @@
+//! Unix pipe.
+//!
+//! See the [`new`] function for documentation.
+
+use std::io;
+use std::os::fd::RawFd;
+
+pub(crate) fn new_raw() -> io::Result<[RawFd; 2]> {
+    let mut fds: [RawFd; 2] = [-1, -1];
+
+    #[cfg(any(
+        target_os = "android",
+        target_os = "dragonfly",
+        target_os = "freebsd",
+        target_os = "fuchsia",
+        target_os = "hurd",
+        target_os = "linux",
+        target_os = "netbsd",
+        target_os = "openbsd",
+        target_os = "illumos",
+        target_os = "redox",
+        target_os = "solaris",
+        target_os = "vita",
+        target_os = "cygwin",
+    ))]
+    unsafe {
+        if libc::pipe2(fds.as_mut_ptr(), libc::O_CLOEXEC | libc::O_NONBLOCK) != 0 {
+            return Err(io::Error::last_os_error());
+        }
+    }
+
+    #[cfg(any(
+        target_os = "aix",
+        target_os = "haiku",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos",
+        target_os = "espidf",
+        target_os = "nto",
+    ))]
+    unsafe {
+        // For platforms that don't have `pipe2(2)` we need to manually set the
+        // correct flags on the file descriptor.
+        if libc::pipe(fds.as_mut_ptr()) != 0 {
+            return Err(io::Error::last_os_error());
+        }
+
+        for fd in &fds {
+            if libc::fcntl(*fd, libc::F_SETFL, libc::O_NONBLOCK) != 0
+                || libc::fcntl(*fd, libc::F_SETFD, libc::FD_CLOEXEC) != 0
+            {
+                let err = io::Error::last_os_error();
+                // Don't leak file descriptors. Can't handle closing error though.
+                let _ = libc::close(fds[0]);
+                let _ = libc::close(fds[1]);
+                return Err(err);
+            }
+        }
+    }
+
+    Ok(fds)
+}
+
+cfg_os_ext! {
+use std::fs::File;
+use std::io::{IoSlice, IoSliceMut, Read, Write};
+use std::os::fd::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd};
+use std::process::{ChildStderr, ChildStdin, ChildStdout};
+
+use crate::io_source::IoSource;
+use crate::{event, Interest, Registry, Token};
+
+/// Create a new non-blocking Unix pipe.
+///
+/// This is a wrapper around Unix's [`pipe(2)`] system call and can be used as
+/// inter-process or thread communication channel.
+///
+/// This channel may be created before forking the process and then one end used
+/// in each process, e.g. the parent process has the sending end to send command
+/// to the child process.
+///
+/// [`pipe(2)`]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/pipe.html
+///
+/// # Events
+///
+/// The [`Sender`] can be registered with [`WRITABLE`] interest to receive
+/// [writable events], the [`Receiver`] with [`READABLE`] interest. Once data is
+/// written to the `Sender` the `Receiver` will receive an [readable event].
+///
+/// In addition to those events, events will also be generated if the other side
+/// is dropped. To check if the `Sender` is dropped you'll need to check
+/// [`is_read_closed`] on events for the `Receiver`, if it returns true the
+/// `Sender` is dropped. On the `Sender` end check [`is_write_closed`], if it
+/// returns true the `Receiver` was dropped. Also see the second example below.
+///
+/// [`WRITABLE`]: Interest::WRITABLE
+/// [writable events]: event::Event::is_writable
+/// [`READABLE`]: Interest::READABLE
+/// [readable event]: event::Event::is_readable
+/// [`is_read_closed`]: event::Event::is_read_closed
+/// [`is_write_closed`]: event::Event::is_write_closed
+///
+/// # Deregistering
+///
+/// Both `Sender` and `Receiver` will deregister themselves when dropped,
+/// **iff** the file descriptors are not duplicated (via [`dup(2)`]).
+///
+/// [`dup(2)`]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/dup.html
+///
+/// # Examples
+///
+/// Simple example that writes data into the sending end and read it from the
+/// receiving end.
+///
+/// ```
+/// use std::io::{self, Read, Write};
+///
+/// use mio::{Poll, Events, Interest, Token};
+/// use mio::unix::pipe;
+///
+/// // Unique tokens for the two ends of the channel.
+/// const PIPE_RECV: Token = Token(0);
+/// const PIPE_SEND: Token = Token(1);
+///
+/// # fn main() -> io::Result<()> {
+/// // Create our `Poll` instance and the `Events` container.
+/// let mut poll = Poll::new()?;
+/// let mut events = Events::with_capacity(8);
+///
+/// // Create a new pipe.
+/// let (mut sender, mut receiver) = pipe::new()?;
+///
+/// // Register both ends of the channel.
+/// poll.registry().register(&mut receiver, PIPE_RECV, Interest::READABLE)?;
+/// poll.registry().register(&mut sender, PIPE_SEND, Interest::WRITABLE)?;
+///
+/// const MSG: &[u8; 11] = b"Hello world";
+///
+/// loop {
+///     poll.poll(&mut events, None)?;
+///
+///     for event in events.iter() {
+///         match event.token() {
+///             PIPE_SEND => sender.write(MSG)
+///                 .and_then(|n| if n != MSG.len() {
+///                         // We'll consider a short write an error in this
+///                         // example. NOTE: we can't use `write_all` with
+///                         // non-blocking I/O.
+///                         Err(io::ErrorKind::WriteZero.into())
+///                     } else {
+///                         Ok(())
+///                     })?,
+///             PIPE_RECV => {
+///                 let mut buf = [0; 11];
+///                 let n = receiver.read(&mut buf)?;
+///                 println!("received: {:?}", &buf[0..n]);
+///                 assert_eq!(n, MSG.len());
+///                 assert_eq!(&buf, &*MSG);
+///                 return Ok(());
+///             },
+///             _ => unreachable!(),
+///         }
+///     }
+/// }
+/// # }
+/// ```
+///
+/// Example that receives an event once the `Sender` is dropped.
+///
+/// ```
+/// # use std::io;
+/// #
+/// # use mio::{Poll, Events, Interest, Token};
+/// # use mio::unix::pipe;
+/// #
+/// # const PIPE_RECV: Token = Token(0);
+/// # const PIPE_SEND: Token = Token(1);
+/// #
+/// # fn main() -> io::Result<()> {
+/// // Same setup as in the example above.
+/// let mut poll = Poll::new()?;
+/// let mut events = Events::with_capacity(8);
+///
+/// let (mut sender, mut receiver) = pipe::new()?;
+///
+/// poll.registry().register(&mut receiver, PIPE_RECV, Interest::READABLE)?;
+/// poll.registry().register(&mut sender, PIPE_SEND, Interest::WRITABLE)?;
+///
+/// // Drop the sender.
+/// drop(sender);
+///
+/// poll.poll(&mut events, None)?;
+///
+/// for event in events.iter() {
+///     match event.token() {
+///         PIPE_RECV if event.is_read_closed() => {
+///             // Detected that the sender was dropped.
+///             println!("Sender dropped!");
+///             return Ok(());
+///         },
+///         _ => unreachable!(),
+///     }
+/// }
+/// # unreachable!();
+/// # }
+/// ```
+pub fn new() -> io::Result<(Sender, Receiver)> {
+    let fds = new_raw()?;
+    // SAFETY: `new_raw` initialised the `fds` above.
+    let r = unsafe { Receiver::from_raw_fd(fds[0]) };
+    let w = unsafe { Sender::from_raw_fd(fds[1]) };
+    Ok((w, r))
+}
+
+/// Sending end of an Unix pipe.
+///
+/// See [`new`] for documentation, including examples.
+#[derive(Debug)]
+pub struct Sender {
+    inner: IoSource<File>,
+}
+
+impl Sender {
+    /// Set the `Sender` into or out of non-blocking mode.
+    pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
+        set_nonblocking(self.inner.as_raw_fd(), nonblocking)
+    }
+
+    /// Execute an I/O operation ensuring that the socket receives more events
+    /// if it hits a [`WouldBlock`] error.
+    ///
+    /// # Notes
+    ///
+    /// This method is required to be called for **all** I/O operations to
+    /// ensure the user will receive events once the socket is ready again after
+    /// returning a [`WouldBlock`] error.
+    ///
+    /// [`WouldBlock`]: io::ErrorKind::WouldBlock
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use std::error::Error;
+    /// #
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// use std::io;
+    /// use std::os::fd::AsRawFd;
+    /// use mio::unix::pipe;
+    ///
+    /// let (sender, receiver) = pipe::new()?;
+    ///
+    /// // Wait until the sender is writable...
+    ///
+    /// // Write to the sender using a direct libc call, of course the
+    /// // `io::Write` implementation would be easier to use.
+    /// let buf = b"hello";
+    /// let n = sender.try_io(|| {
+    ///     let buf_ptr = &buf as *const _ as *const _;
+    ///     let res = unsafe { libc::write(sender.as_raw_fd(), buf_ptr, buf.len()) };
+    ///     if res != -1 {
+    ///         Ok(res as usize)
+    ///     } else {
+    ///         // If EAGAIN or EWOULDBLOCK is set by libc::write, the closure
+    ///         // should return `WouldBlock` error.
+    ///         Err(io::Error::last_os_error())
+    ///     }
+    /// })?;
+    /// eprintln!("write {} bytes", n);
+    ///
+    /// // Wait until the receiver is readable...
+    ///
+    /// // Read from the receiver using a direct libc call, of course the
+    /// // `io::Read` implementation would be easier to use.
+    /// let mut buf = [0; 512];
+    /// let n = receiver.try_io(|| {
+    ///     let buf_ptr = &mut buf as *mut _ as *mut _;
+    ///     let res = unsafe { libc::read(receiver.as_raw_fd(), buf_ptr, buf.len()) };
+    ///     if res != -1 {
+    ///         Ok(res as usize)
+    ///     } else {
+    ///         // If EAGAIN or EWOULDBLOCK is set by libc::read, the closure
+    ///         // should return `WouldBlock` error.
+    ///         Err(io::Error::last_os_error())
+    ///     }
+    /// })?;
+    /// eprintln!("read {} bytes", n);
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn try_io<F, T>(&self, f: F) -> io::Result<T>
+    where
+        F: FnOnce() -> io::Result<T>,
+    {
+        self.inner.do_io(|_| f())
+    }
+}
+
+impl event::Source for Sender {
+    fn register(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        self.inner.register(registry, token, interests)
+    }
+
+    fn reregister(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        self.inner.reregister(registry, token, interests)
+    }
+
+    fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
+        self.inner.deregister(registry)
+    }
+}
+
+impl Write for Sender {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.inner.do_io(|mut sender| sender.write(buf))
+    }
+
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        self.inner.do_io(|mut sender| sender.write_vectored(bufs))
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.inner.do_io(|mut sender| sender.flush())
+    }
+}
+
+impl Write for &Sender {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.inner.do_io(|mut sender| sender.write(buf))
+    }
+
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        self.inner.do_io(|mut sender| sender.write_vectored(bufs))
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.inner.do_io(|mut sender| sender.flush())
+    }
+}
+
+/// # Notes
+///
+/// The underlying pipe is **not** set to non-blocking.
+impl From<ChildStdin> for Sender {
+    fn from(stdin: ChildStdin) -> Sender {
+        // Safety: `ChildStdin` is guaranteed to be a valid file descriptor.
+        unsafe { Sender::from_raw_fd(stdin.into_raw_fd()) }
+    }
+}
+
+impl FromRawFd for Sender {
+    unsafe fn from_raw_fd(fd: RawFd) -> Sender {
+        Sender {
+            inner: IoSource::new(File::from_raw_fd(fd)),
+        }
+    }
+}
+
+impl AsRawFd for Sender {
+    fn as_raw_fd(&self) -> RawFd {
+        self.inner.as_raw_fd()
+    }
+}
+
+impl IntoRawFd for Sender {
+    fn into_raw_fd(self) -> RawFd {
+        self.inner.into_inner().into_raw_fd()
+    }
+}
+
+impl From<Sender> for OwnedFd {
+    fn from(sender: Sender) -> Self {
+        sender.inner.into_inner().into()
+    }
+}
+
+impl AsFd for Sender {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.inner.as_fd()
+    }
+}
+
+impl From<OwnedFd> for Sender {
+    fn from(fd: OwnedFd) -> Self {
+        Sender {
+            inner: IoSource::new(File::from(fd)),
+        }
+    }
+}
+
+/// Receiving end of an Unix pipe.
+///
+/// See [`new`] for documentation, including examples.
+#[derive(Debug)]
+pub struct Receiver {
+    inner: IoSource<File>,
+}
+
+impl Receiver {
+    /// Set the `Receiver` into or out of non-blocking mode.
+    pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
+        set_nonblocking(self.inner.as_raw_fd(), nonblocking)
+    }
+
+    /// Execute an I/O operation ensuring that the socket receives more events
+    /// if it hits a [`WouldBlock`] error.
+    ///
+    /// # Notes
+    ///
+    /// This method is required to be called for **all** I/O operations to
+    /// ensure the user will receive events once the socket is ready again after
+    /// returning a [`WouldBlock`] error.
+    ///
+    /// [`WouldBlock`]: io::ErrorKind::WouldBlock
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use std::error::Error;
+    /// #
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// use std::io;
+    /// use std::os::fd::AsRawFd;
+    /// use mio::unix::pipe;
+    ///
+    /// let (sender, receiver) = pipe::new()?;
+    ///
+    /// // Wait until the sender is writable...
+    ///
+    /// // Write to the sender using a direct libc call, of course the
+    /// // `io::Write` implementation would be easier to use.
+    /// let buf = b"hello";
+    /// let n = sender.try_io(|| {
+    ///     let buf_ptr = &buf as *const _ as *const _;
+    ///     let res = unsafe { libc::write(sender.as_raw_fd(), buf_ptr, buf.len()) };
+    ///     if res != -1 {
+    ///         Ok(res as usize)
+    ///     } else {
+    ///         // If EAGAIN or EWOULDBLOCK is set by libc::write, the closure
+    ///         // should return `WouldBlock` error.
+    ///         Err(io::Error::last_os_error())
+    ///     }
+    /// })?;
+    /// eprintln!("write {} bytes", n);
+    ///
+    /// // Wait until the receiver is readable...
+    ///
+    /// // Read from the receiver using a direct libc call, of course the
+    /// // `io::Read` implementation would be easier to use.
+    /// let mut buf = [0; 512];
+    /// let n = receiver.try_io(|| {
+    ///     let buf_ptr = &mut buf as *mut _ as *mut _;
+    ///     let res = unsafe { libc::read(receiver.as_raw_fd(), buf_ptr, buf.len()) };
+    ///     if res != -1 {
+    ///         Ok(res as usize)
+    ///     } else {
+    ///         // If EAGAIN or EWOULDBLOCK is set by libc::read, the closure
+    ///         // should return `WouldBlock` error.
+    ///         Err(io::Error::last_os_error())
+    ///     }
+    /// })?;
+    /// eprintln!("read {} bytes", n);
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn try_io<F, T>(&self, f: F) -> io::Result<T>
+    where
+        F: FnOnce() -> io::Result<T>,
+    {
+        self.inner.do_io(|_| f())
+    }
+}
+
+impl event::Source for Receiver {
+    fn register(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        self.inner.register(registry, token, interests)
+    }
+
+    fn reregister(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        self.inner.reregister(registry, token, interests)
+    }
+
+    fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
+        self.inner.deregister(registry)
+    }
+}
+
+impl Read for Receiver {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.inner.do_io(|mut sender| sender.read(buf))
+    }
+
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        self.inner.do_io(|mut sender| sender.read_vectored(bufs))
+    }
+}
+
+impl Read for &Receiver {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.inner.do_io(|mut sender| sender.read(buf))
+    }
+
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        self.inner.do_io(|mut sender| sender.read_vectored(bufs))
+    }
+}
+
+/// # Notes
+///
+/// The underlying pipe is **not** set to non-blocking.
+impl From<ChildStdout> for Receiver {
+    fn from(stdout: ChildStdout) -> Receiver {
+        // Safety: `ChildStdout` is guaranteed to be a valid file descriptor.
+        unsafe { Receiver::from_raw_fd(stdout.into_raw_fd()) }
+    }
+}
+
+/// # Notes
+///
+/// The underlying pipe is **not** set to non-blocking.
+impl From<ChildStderr> for Receiver {
+    fn from(stderr: ChildStderr) -> Receiver {
+        // Safety: `ChildStderr` is guaranteed to be a valid file descriptor.
+        unsafe { Receiver::from_raw_fd(stderr.into_raw_fd()) }
+    }
+}
+
+impl IntoRawFd for Receiver {
+    fn into_raw_fd(self) -> RawFd {
+        self.inner.into_inner().into_raw_fd()
+    }
+}
+
+impl AsRawFd for Receiver {
+    fn as_raw_fd(&self) -> RawFd {
+        self.inner.as_raw_fd()
+    }
+}
+
+impl FromRawFd for Receiver {
+    unsafe fn from_raw_fd(fd: RawFd) -> Receiver {
+        Receiver {
+            inner: IoSource::new(File::from_raw_fd(fd)),
+        }
+    }
+}
+
+impl From<Receiver> for OwnedFd {
+    fn from(receiver: Receiver) -> Self {
+        receiver.inner.into_inner().into()
+    }
+}
+
+impl AsFd for Receiver {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.inner.as_fd()
+    }
+}
+
+impl From<OwnedFd> for Receiver {
+    fn from(fd: OwnedFd) -> Self {
+        Receiver {
+            inner: IoSource::new(File::from(fd)),
+        }
+    }
+}
+
+#[cfg(not(any(target_os = "aix", target_os = "illumos", target_os = "solaris", target_os = "vita")))]
+fn set_nonblocking(fd: RawFd, nonblocking: bool) -> io::Result<()> {
+    let value = nonblocking as libc::c_int;
+    if unsafe { libc::ioctl(fd, libc::FIONBIO, &value) } == -1 {
+        Err(io::Error::last_os_error())
+    } else {
+        Ok(())
+    }
+}
+
+#[cfg(any(target_os = "aix", target_os = "illumos", target_os = "solaris", target_os = "vita"))]
+fn set_nonblocking(fd: RawFd, nonblocking: bool) -> io::Result<()> {
+    let flags = unsafe { libc::fcntl(fd, libc::F_GETFL) };
+    if flags < 0 {
+        return Err(io::Error::last_os_error());
+    }
+
+    let nflags = if nonblocking {
+        flags | libc::O_NONBLOCK
+    } else {
+        flags & !libc::O_NONBLOCK
+    };
+
+    if flags != nflags {
+        if unsafe { libc::fcntl(fd, libc::F_SETFL, nflags) } < 0 {
+            return Err(io::Error::last_os_error());
+        }
+    }
+
+    Ok(())
+}
+} // `cfg_os_ext!`.

vendor/mio/src/sys/unix/selector/epoll.rs

@@ -0,0 +1,237 @@
+use std::io;
+use std::os::fd::{AsRawFd, FromRawFd, OwnedFd, RawFd};
+#[cfg(debug_assertions)]
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::time::Duration;
+
+use libc::{EPOLLET, EPOLLIN, EPOLLOUT, EPOLLPRI, EPOLLRDHUP};
+
+use crate::{Interest, Token};
+
+cfg_io_source! {
+    use std::ptr;
+}
+
+/// Unique id for use as `SelectorId`.
+#[cfg(debug_assertions)]
+static NEXT_ID: AtomicUsize = AtomicUsize::new(1);
+
+#[derive(Debug)]
+pub struct Selector {
+    #[cfg(debug_assertions)]
+    id: usize,
+    ep: OwnedFd,
+}
+
+impl Selector {
+    pub fn new() -> io::Result<Selector> {
+        // SAFETY: `epoll_create1(2)` ensures the fd is valid.
+        let ep = unsafe { OwnedFd::from_raw_fd(syscall!(epoll_create1(libc::EPOLL_CLOEXEC))?) };
+        Ok(Selector {
+            #[cfg(debug_assertions)]
+            id: NEXT_ID.fetch_add(1, Ordering::Relaxed),
+            ep,
+        })
+    }
+
+    pub fn try_clone(&self) -> io::Result<Selector> {
+        self.ep.try_clone().map(|ep| Selector {
+            // It's the same selector, so we use the same id.
+            #[cfg(debug_assertions)]
+            id: self.id,
+            ep,
+        })
+    }
+
+    pub fn select(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<()> {
+        let timeout = timeout
+            .map(|to| {
+                // `Duration::as_millis` truncates, so round up. This avoids
+                // turning sub-millisecond timeouts into a zero timeout, unless
+                // the caller explicitly requests that by specifying a zero
+                // timeout.
+                to.checked_add(Duration::from_nanos(999_999))
+                    .unwrap_or(to)
+                    .as_millis() as libc::c_int
+            })
+            .unwrap_or(-1);
+
+        events.clear();
+        syscall!(epoll_wait(
+            self.ep.as_raw_fd(),
+            events.as_mut_ptr(),
+            events.capacity() as i32,
+            timeout,
+        ))
+        .map(|n_events| {
+            // This is safe because `epoll_wait` ensures that `n_events` are
+            // assigned.
+            unsafe { events.set_len(n_events as usize) };
+        })
+    }
+
+    pub fn register(&self, fd: RawFd, token: Token, interests: Interest) -> io::Result<()> {
+        let mut event = libc::epoll_event {
+            events: interests_to_epoll(interests),
+            u64: usize::from(token) as u64,
+            #[cfg(target_os = "redox")]
+            _pad: 0,
+        };
+
+        let ep = self.ep.as_raw_fd();
+        syscall!(epoll_ctl(ep, libc::EPOLL_CTL_ADD, fd, &mut event)).map(|_| ())
+    }
+
+    cfg_any_os_ext! {
+    pub fn reregister(&self, fd: RawFd, token: Token, interests: Interest) -> io::Result<()> {
+        let mut event = libc::epoll_event {
+            events: interests_to_epoll(interests),
+            u64: usize::from(token) as u64,
+            #[cfg(target_os = "redox")]
+            _pad: 0,
+        };
+
+        let ep = self.ep.as_raw_fd();
+        syscall!(epoll_ctl(ep, libc::EPOLL_CTL_MOD, fd, &mut event)).map(|_| ())
+    }
+
+    pub fn deregister(&self, fd: RawFd) -> io::Result<()> {
+        let ep = self.ep.as_raw_fd();
+        syscall!(epoll_ctl(ep, libc::EPOLL_CTL_DEL, fd, ptr::null_mut())).map(|_| ())
+    }
+    }
+}
+
+cfg_io_source! {
+    impl Selector {
+        #[cfg(debug_assertions)]
+        pub fn id(&self) -> usize {
+            self.id
+        }
+    }
+}
+
+impl AsRawFd for Selector {
+    fn as_raw_fd(&self) -> RawFd {
+        self.ep.as_raw_fd()
+    }
+}
+
+fn interests_to_epoll(interests: Interest) -> u32 {
+    let mut kind = EPOLLET;
+
+    if interests.is_readable() {
+        kind = kind | EPOLLIN | EPOLLRDHUP;
+    }
+
+    if interests.is_writable() {
+        kind |= EPOLLOUT;
+    }
+
+    if interests.is_priority() {
+        kind |= EPOLLPRI;
+    }
+
+    kind as u32
+}
+
+pub type Event = libc::epoll_event;
+pub type Events = Vec<Event>;
+
+pub mod event {
+    use std::fmt;
+
+    use crate::sys::Event;
+    use crate::Token;
+
+    pub fn token(event: &Event) -> Token {
+        Token(event.u64 as usize)
+    }
+
+    pub fn is_readable(event: &Event) -> bool {
+        (event.events as libc::c_int & libc::EPOLLIN) != 0
+            || (event.events as libc::c_int & libc::EPOLLPRI) != 0
+    }
+
+    pub fn is_writable(event: &Event) -> bool {
+        (event.events as libc::c_int & libc::EPOLLOUT) != 0
+    }
+
+    pub fn is_error(event: &Event) -> bool {
+        (event.events as libc::c_int & libc::EPOLLERR) != 0
+    }
+
+    pub fn is_read_closed(event: &Event) -> bool {
+        // Both halves of the socket have closed
+        event.events as libc::c_int & libc::EPOLLHUP != 0
+            // Socket has received FIN or called shutdown(SHUT_RD)
+            || (event.events as libc::c_int & libc::EPOLLIN != 0
+                && event.events as libc::c_int & libc::EPOLLRDHUP != 0)
+    }
+
+    pub fn is_write_closed(event: &Event) -> bool {
+        // Both halves of the socket have closed
+        event.events as libc::c_int & libc::EPOLLHUP != 0
+            // Unix pipe write end has closed
+            || (event.events as libc::c_int & libc::EPOLLOUT != 0
+                && event.events as libc::c_int & libc::EPOLLERR != 0)
+            // The other side (read end) of a Unix pipe has closed.
+            || event.events as libc::c_int == libc::EPOLLERR
+    }
+
+    pub fn is_priority(event: &Event) -> bool {
+        (event.events as libc::c_int & libc::EPOLLPRI) != 0
+    }
+
+    pub fn is_aio(_: &Event) -> bool {
+        // Not supported in the kernel, only in libc.
+        false
+    }
+
+    pub fn is_lio(_: &Event) -> bool {
+        // Not supported.
+        false
+    }
+
+    pub fn debug_details(f: &mut fmt::Formatter<'_>, event: &Event) -> fmt::Result {
+        #[allow(clippy::trivially_copy_pass_by_ref)]
+        fn check_events(got: &u32, want: &libc::c_int) -> bool {
+            (*got as libc::c_int & want) != 0
+        }
+        debug_detail!(
+            EventsDetails(u32),
+            check_events,
+            libc::EPOLLIN,
+            libc::EPOLLPRI,
+            libc::EPOLLOUT,
+            libc::EPOLLRDNORM,
+            libc::EPOLLRDBAND,
+            libc::EPOLLWRNORM,
+            libc::EPOLLWRBAND,
+            libc::EPOLLMSG,
+            libc::EPOLLERR,
+            libc::EPOLLHUP,
+            libc::EPOLLET,
+            libc::EPOLLRDHUP,
+            libc::EPOLLONESHOT,
+            libc::EPOLLEXCLUSIVE,
+            libc::EPOLLWAKEUP,
+            libc::EPOLL_CLOEXEC,
+        );
+
+        // Can't reference fields in packed structures.
+        let e_u64 = event.u64;
+        f.debug_struct("epoll_event")
+            .field("events", &EventsDetails(event.events))
+            .field("u64", &e_u64)
+            .finish()
+    }
+}
+
+// No special requirement from the implementation around waking.
+pub(crate) use crate::sys::unix::waker::Waker;
+
+cfg_io_source! {
+    mod stateless_io_source;
+    pub(crate) use stateless_io_source::IoSourceState;
+}

vendor/mio/src/sys/unix/selector/kqueue.rs

@@ -0,0 +1,918 @@
+use std::mem;
+use std::mem::MaybeUninit;
+use std::ops::{Deref, DerefMut};
+use std::os::fd::{AsRawFd, FromRawFd, OwnedFd, RawFd};
+use std::slice;
+#[cfg(debug_assertions)]
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::time::Duration;
+use std::{cmp, io, ptr};
+
+use crate::Interest;
+use crate::Token;
+
+/// Unique id for use as `SelectorId`.
+#[cfg(debug_assertions)]
+static NEXT_ID: AtomicUsize = AtomicUsize::new(1);
+
+// Type of the `nchanges` and `nevents` parameters in the `kevent` function.
+#[cfg(not(target_os = "netbsd"))]
+type Count = libc::c_int;
+#[cfg(target_os = "netbsd")]
+type Count = libc::size_t;
+
+// Type of the `filter` field in the `kevent` structure.
+#[cfg(any(target_os = "dragonfly", target_os = "freebsd", target_os = "openbsd"))]
+type Filter = libc::c_short;
+#[cfg(any(
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "tvos",
+    target_os = "visionos",
+    target_os = "watchos"
+))]
+type Filter = i16;
+#[cfg(target_os = "netbsd")]
+type Filter = u32;
+
+// Type of the `flags` field in the `kevent` structure.
+#[cfg(any(target_os = "dragonfly", target_os = "freebsd", target_os = "openbsd"))]
+type Flags = libc::c_ushort;
+#[cfg(any(
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "tvos",
+    target_os = "visionos",
+    target_os = "watchos"
+))]
+type Flags = u16;
+#[cfg(target_os = "netbsd")]
+type Flags = u32;
+
+// Type of the `udata` field in the `kevent` structure.
+type UData = *mut libc::c_void;
+
+macro_rules! kevent {
+    ($id: expr, $filter: expr, $flags: expr, $data: expr) => {
+        libc::kevent {
+            ident: $id as libc::uintptr_t,
+            filter: $filter as Filter,
+            flags: $flags,
+            udata: $data as UData,
+            ..unsafe { mem::zeroed() }
+        }
+    };
+}
+
+#[derive(Debug)]
+pub struct Selector {
+    #[cfg(debug_assertions)]
+    id: usize,
+    kq: OwnedFd,
+}
+
+impl Selector {
+    pub fn new() -> io::Result<Selector> {
+        // SAFETY: `kqueue(2)` ensures the fd is valid.
+        let kq = unsafe { OwnedFd::from_raw_fd(syscall!(kqueue())?) };
+        syscall!(fcntl(kq.as_raw_fd(), libc::F_SETFD, libc::FD_CLOEXEC))?;
+        Ok(Selector {
+            #[cfg(debug_assertions)]
+            id: NEXT_ID.fetch_add(1, Ordering::Relaxed),
+            kq,
+        })
+    }
+
+    pub fn try_clone(&self) -> io::Result<Selector> {
+        self.kq.try_clone().map(|kq| Selector {
+            // It's the same selector, so we use the same id.
+            #[cfg(debug_assertions)]
+            id: self.id,
+            kq,
+        })
+    }
+
+    pub fn select(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<()> {
+        let timeout = timeout.map(|to| libc::timespec {
+            tv_sec: cmp::min(to.as_secs(), libc::time_t::MAX as u64) as libc::time_t,
+            // `Duration::subsec_nanos` is guaranteed to be less than one
+            // billion (the number of nanoseconds in a second), making the
+            // cast to i32 safe. The cast itself is needed for platforms
+            // where C's long is only 32 bits.
+            tv_nsec: libc::c_long::from(to.subsec_nanos() as i32),
+        });
+        let timeout = timeout
+            .as_ref()
+            .map(|s| s as *const _)
+            .unwrap_or(ptr::null_mut());
+
+        events.clear();
+        syscall!(kevent(
+            self.kq.as_raw_fd(),
+            ptr::null(),
+            0,
+            events.as_mut_ptr().cast(),
+            events.capacity() as Count,
+            timeout,
+        ))
+        .map(|n_events| {
+            // This is safe because `kevent` ensures that `n_events` are
+            // assigned.
+            unsafe { events.set_len(n_events as usize) };
+        })
+    }
+
+    #[cfg_attr(not(feature = "os-ext"), allow(dead_code))]
+    pub fn register(&self, fd: RawFd, token: Token, interests: Interest) -> io::Result<()> {
+        let flags = libc::EV_CLEAR | libc::EV_RECEIPT | libc::EV_ADD;
+        // At most we need two changes, but maybe we only need 1.
+        let mut changes: [MaybeUninit<libc::kevent>; 2] =
+            [MaybeUninit::uninit(), MaybeUninit::uninit()];
+        let mut n_changes = 0;
+
+        if interests.is_writable() {
+            let kevent = kevent!(fd, libc::EVFILT_WRITE, flags, token.0);
+            changes[n_changes] = MaybeUninit::new(kevent);
+            n_changes += 1;
+        }
+
+        if interests.is_readable() {
+            let kevent = kevent!(fd, libc::EVFILT_READ, flags, token.0);
+            changes[n_changes] = MaybeUninit::new(kevent);
+            n_changes += 1;
+        }
+
+        // Older versions of macOS (OS X 10.11 and 10.10 have been witnessed)
+        // can return EPIPE when registering a pipe file descriptor where the
+        // other end has already disappeared. For example code that creates a
+        // pipe, closes a file descriptor, and then registers the other end will
+        // see an EPIPE returned from `register`.
+        //
+        // It also turns out that kevent will still report events on the file
+        // descriptor, telling us that it's readable/hup at least after we've
+        // done this registration. As a result we just ignore `EPIPE` here
+        // instead of propagating it.
+        //
+        // More info can be found at tokio-rs/mio#582.
+        let changes = unsafe {
+            // This is safe because we ensure that at least `n_changes` are in
+            // the array.
+            slice::from_raw_parts_mut(changes[0].as_mut_ptr(), n_changes)
+        };
+        kevent_register(self.kq.as_raw_fd(), changes, &[libc::EPIPE as i64])
+    }
+
+    cfg_any_os_ext! {
+    pub fn reregister(&self, fd: RawFd, token: Token, interests: Interest) -> io::Result<()> {
+        let flags = libc::EV_CLEAR | libc::EV_RECEIPT;
+        let write_flags = if interests.is_writable() {
+            flags | libc::EV_ADD
+        } else {
+            flags | libc::EV_DELETE
+        };
+        let read_flags = if interests.is_readable() {
+            flags | libc::EV_ADD
+        } else {
+            flags | libc::EV_DELETE
+        };
+
+        let mut changes: [libc::kevent; 2] = [
+            kevent!(fd, libc::EVFILT_WRITE, write_flags, token.0),
+            kevent!(fd, libc::EVFILT_READ, read_flags, token.0),
+        ];
+
+        // Since there is no way to check with which interests the fd was
+        // registered we modify both readable and write, adding it when required
+        // and removing it otherwise, ignoring the ENOENT error when it comes
+        // up. The ENOENT error informs us that a filter we're trying to remove
+        // wasn't there in first place, but we don't really care since our goal
+        // is accomplished.
+        //
+        // For the explanation of ignoring `EPIPE` see `register`.
+        kevent_register(
+            self.kq.as_raw_fd(),
+            &mut changes,
+            &[libc::ENOENT as i64, libc::EPIPE as i64],
+        )
+    }
+
+    pub fn deregister(&self, fd: RawFd) -> io::Result<()> {
+        let flags = libc::EV_DELETE | libc::EV_RECEIPT;
+        let mut changes: [libc::kevent; 2] = [
+            kevent!(fd, libc::EVFILT_WRITE, flags, 0),
+            kevent!(fd, libc::EVFILT_READ, flags, 0),
+        ];
+
+        // Since there is no way to check with which interests the fd was
+        // registered we remove both filters (readable and writeable) and ignore
+        // the ENOENT error when it comes up. The ENOENT error informs us that
+        // the filter wasn't there in first place, but we don't really care
+        // about that since our goal is to remove it.
+        kevent_register(self.kq.as_raw_fd(), &mut changes, &[libc::ENOENT as i64])
+    }
+    }
+
+    // Used by `Waker`.
+    #[cfg(any(
+        target_os = "freebsd",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos"
+    ))]
+    pub fn setup_waker(&self, token: Token) -> io::Result<()> {
+        // First attempt to accept user space notifications.
+        let mut kevent = kevent!(
+            0,
+            libc::EVFILT_USER,
+            libc::EV_ADD | libc::EV_CLEAR | libc::EV_RECEIPT,
+            token.0
+        );
+
+        let kq = self.kq.as_raw_fd();
+        syscall!(kevent(kq, &kevent, 1, &mut kevent, 1, ptr::null())).and_then(|_| {
+            if (kevent.flags & libc::EV_ERROR) != 0 && kevent.data != 0 {
+                Err(io::Error::from_raw_os_error(kevent.data as i32))
+            } else {
+                Ok(())
+            }
+        })
+    }
+
+    // Used by `Waker`.
+    #[cfg(any(
+        target_os = "freebsd",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos"
+    ))]
+    pub fn wake(&self, token: Token) -> io::Result<()> {
+        let mut kevent = kevent!(
+            0,
+            libc::EVFILT_USER,
+            libc::EV_ADD | libc::EV_RECEIPT,
+            token.0
+        );
+        kevent.fflags = libc::NOTE_TRIGGER;
+
+        let kq = self.kq.as_raw_fd();
+        syscall!(kevent(kq, &kevent, 1, &mut kevent, 1, ptr::null())).and_then(|_| {
+            if (kevent.flags & libc::EV_ERROR) != 0 && kevent.data != 0 {
+                Err(io::Error::from_raw_os_error(kevent.data as i32))
+            } else {
+                Ok(())
+            }
+        })
+    }
+}
+
+/// Register `changes` with `kq`ueue.
+fn kevent_register(
+    kq: RawFd,
+    changes: &mut [libc::kevent],
+    ignored_errors: &[i64],
+) -> io::Result<()> {
+    syscall!(kevent(
+        kq,
+        changes.as_ptr(),
+        changes.len() as Count,
+        changes.as_mut_ptr(),
+        changes.len() as Count,
+        ptr::null(),
+    ))
+    .map(|_| ())
+    .or_else(|err| {
+        // According to the manual page of FreeBSD: "When kevent() call fails
+        // with EINTR error, all changes in the changelist have been applied",
+        // so we can safely ignore it.
+        if err.raw_os_error() == Some(libc::EINTR) {
+            Ok(())
+        } else {
+            Err(err)
+        }
+    })
+    .and_then(|()| check_errors(changes, ignored_errors))
+}
+
+/// Check all events for possible errors, it returns the first error found.
+fn check_errors(events: &[libc::kevent], ignored_errors: &[i64]) -> io::Result<()> {
+    for event in events {
+        // We can't use references to packed structures (in checking the ignored
+        // errors), so we need copy the data out before use.
+        let data = event.data as _;
+        // Check for the error flag, the actual error will be in the `data`
+        // field.
+        if (event.flags & libc::EV_ERROR != 0) && data != 0 && !ignored_errors.contains(&data) {
+            return Err(io::Error::from_raw_os_error(data as i32));
+        }
+    }
+    Ok(())
+}
+
+cfg_io_source! {
+    #[cfg(debug_assertions)]
+    impl Selector {
+        pub fn id(&self) -> usize {
+            self.id
+        }
+    }
+}
+
+impl AsRawFd for Selector {
+    fn as_raw_fd(&self) -> RawFd {
+        self.kq.as_raw_fd()
+    }
+}
+
+#[repr(transparent)]
+#[derive(Clone)]
+pub struct Event(libc::kevent);
+
+unsafe impl Send for Event {}
+unsafe impl Sync for Event {}
+
+impl Deref for Event {
+    type Target = libc::kevent;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for Event {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+pub struct Events(Vec<Event>);
+
+impl Deref for Events {
+    type Target = Vec<Event>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for Events {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl Events {
+    pub fn with_capacity(capacity: usize) -> Events {
+        Events(Vec::with_capacity(capacity))
+    }
+}
+
+// `Events` cannot derive `Send` or `Sync` because of the
+// `udata: *mut ::c_void` field in `libc::kevent`. However, `Events`'s public
+// API treats the `udata` field as a `uintptr_t` which is `Send`. `Sync` is
+// safe because with a `events: &Events` value, the only access to the `udata`
+// field is through `fn token(event: &Event)` which cannot mutate the field.
+unsafe impl Send for Events {}
+unsafe impl Sync for Events {}
+
+pub mod event {
+    use std::fmt;
+
+    use crate::sys::Event;
+    use crate::Token;
+
+    use super::{Filter, Flags};
+
+    pub fn token(event: &Event) -> Token {
+        Token(event.0.udata as usize)
+    }
+
+    pub fn is_readable(event: &Event) -> bool {
+        event.0.filter == libc::EVFILT_READ || {
+            #[cfg(any(
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            // Used by the `Awakener`. On platforms that use `eventfd` or a unix
+            // pipe it will emit a readable event so we'll fake that here as
+            // well.
+            {
+                event.filter == libc::EVFILT_USER
+            }
+            #[cfg(not(any(
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            )))]
+            {
+                false
+            }
+        }
+    }
+
+    pub fn is_writable(event: &Event) -> bool {
+        event.0.filter == libc::EVFILT_WRITE
+    }
+
+    pub fn is_error(event: &Event) -> bool {
+        (event.0.flags & libc::EV_ERROR) != 0 ||
+            // When the read end of the socket is closed, EV_EOF is set on
+            // flags, and fflags contains the error if there is one.
+            (event.0.flags & libc::EV_EOF) != 0 && event.0.fflags != 0
+    }
+
+    pub fn is_read_closed(event: &Event) -> bool {
+        event.0.filter == libc::EVFILT_READ && event.0.flags & libc::EV_EOF != 0
+    }
+
+    pub fn is_write_closed(event: &Event) -> bool {
+        event.0.filter == libc::EVFILT_WRITE && event.0.flags & libc::EV_EOF != 0
+    }
+
+    pub fn is_priority(_: &Event) -> bool {
+        // kqueue doesn't have priority indicators.
+        false
+    }
+
+    #[allow(unused_variables)] // `event` is not used on some platforms.
+    pub fn is_aio(event: &Event) -> bool {
+        #[cfg(any(
+            target_os = "dragonfly",
+            target_os = "freebsd",
+            target_os = "ios",
+            target_os = "macos",
+            target_os = "tvos",
+            target_os = "visionos",
+            target_os = "watchos",
+        ))]
+        {
+            event.0.filter == libc::EVFILT_AIO
+        }
+        #[cfg(not(any(
+            target_os = "dragonfly",
+            target_os = "freebsd",
+            target_os = "ios",
+            target_os = "macos",
+            target_os = "tvos",
+            target_os = "visionos",
+            target_os = "watchos",
+        )))]
+        {
+            false
+        }
+    }
+
+    #[allow(unused_variables)] // `event` is only used on FreeBSD.
+    pub fn is_lio(event: &Event) -> bool {
+        #[cfg(target_os = "freebsd")]
+        {
+            event.0.filter == libc::EVFILT_LIO
+        }
+        #[cfg(not(target_os = "freebsd"))]
+        {
+            false
+        }
+    }
+
+    pub fn debug_details(f: &mut fmt::Formatter<'_>, event: &Event) -> fmt::Result {
+        debug_detail!(
+            FilterDetails(Filter),
+            PartialEq::eq,
+            libc::EVFILT_READ,
+            libc::EVFILT_WRITE,
+            libc::EVFILT_AIO,
+            libc::EVFILT_VNODE,
+            libc::EVFILT_PROC,
+            libc::EVFILT_SIGNAL,
+            libc::EVFILT_TIMER,
+            #[cfg(target_os = "freebsd")]
+            libc::EVFILT_PROCDESC,
+            #[cfg(any(
+                target_os = "freebsd",
+                target_os = "dragonfly",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ))]
+            libc::EVFILT_FS,
+            #[cfg(target_os = "freebsd")]
+            libc::EVFILT_LIO,
+            #[cfg(any(
+                target_os = "freebsd",
+                target_os = "dragonfly",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ))]
+            libc::EVFILT_USER,
+            #[cfg(target_os = "freebsd")]
+            libc::EVFILT_SENDFILE,
+            #[cfg(target_os = "freebsd")]
+            libc::EVFILT_EMPTY,
+            #[cfg(target_os = "dragonfly")]
+            libc::EVFILT_EXCEPT,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::EVFILT_MACHPORT,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::EVFILT_VM,
+        );
+
+        #[allow(clippy::trivially_copy_pass_by_ref)]
+        fn check_flag(got: &Flags, want: &Flags) -> bool {
+            (got & want) != 0
+        }
+        debug_detail!(
+            FlagsDetails(Flags),
+            check_flag,
+            libc::EV_ADD,
+            libc::EV_DELETE,
+            libc::EV_ENABLE,
+            libc::EV_DISABLE,
+            libc::EV_ONESHOT,
+            libc::EV_CLEAR,
+            libc::EV_RECEIPT,
+            libc::EV_DISPATCH,
+            #[cfg(target_os = "freebsd")]
+            libc::EV_DROP,
+            libc::EV_FLAG1,
+            libc::EV_ERROR,
+            libc::EV_EOF,
+            // Not stable across OS versions on OpenBSD.
+            #[cfg(not(target_os = "openbsd"))]
+            libc::EV_SYSFLAGS,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::EV_FLAG0,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::EV_POLL,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::EV_OOBAND,
+            #[cfg(target_os = "dragonfly")]
+            libc::EV_NODATA,
+        );
+
+        #[allow(clippy::trivially_copy_pass_by_ref)]
+        fn check_fflag(got: &u32, want: &u32) -> bool {
+            (got & want) != 0
+        }
+        debug_detail!(
+            FflagsDetails(u32),
+            check_fflag,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ))]
+            libc::NOTE_TRIGGER,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ))]
+            libc::NOTE_FFNOP,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ))]
+            libc::NOTE_FFAND,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ))]
+            libc::NOTE_FFOR,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ))]
+            libc::NOTE_FFCOPY,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ))]
+            libc::NOTE_FFCTRLMASK,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos",
+            ))]
+            libc::NOTE_FFLAGSMASK,
+            libc::NOTE_LOWAT,
+            libc::NOTE_DELETE,
+            libc::NOTE_WRITE,
+            #[cfg(target_os = "dragonfly")]
+            libc::NOTE_OOB,
+            #[cfg(target_os = "openbsd")]
+            libc::NOTE_EOF,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_EXTEND,
+            libc::NOTE_ATTRIB,
+            libc::NOTE_LINK,
+            libc::NOTE_RENAME,
+            libc::NOTE_REVOKE,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_NONE,
+            #[cfg(any(target_os = "openbsd"))]
+            libc::NOTE_TRUNCATE,
+            libc::NOTE_EXIT,
+            libc::NOTE_FORK,
+            libc::NOTE_EXEC,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_SIGNAL,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_EXITSTATUS,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_EXIT_DETAIL,
+            libc::NOTE_PDATAMASK,
+            libc::NOTE_PCTRLMASK,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "netbsd",
+                target_os = "openbsd",
+            ))]
+            libc::NOTE_TRACK,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "netbsd",
+                target_os = "openbsd",
+            ))]
+            libc::NOTE_TRACKERR,
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "netbsd",
+                target_os = "openbsd",
+            ))]
+            libc::NOTE_CHILD,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_EXIT_DETAIL_MASK,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_EXIT_DECRYPTFAIL,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_EXIT_MEMORY,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_EXIT_CSERROR,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_VM_PRESSURE,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_VM_PRESSURE_TERMINATE,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_VM_PRESSURE_SUDDEN_TERMINATE,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_VM_ERROR,
+            #[cfg(any(
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_SECONDS,
+            #[cfg(any(target_os = "freebsd"))]
+            libc::NOTE_MSECONDS,
+            #[cfg(any(
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_USECONDS,
+            #[cfg(any(
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_NSECONDS,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_ABSOLUTE,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_LEEWAY,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_CRITICAL,
+            #[cfg(any(
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "tvos",
+                target_os = "visionos",
+                target_os = "watchos"
+            ))]
+            libc::NOTE_BACKGROUND,
+        );
+
+        // Can't reference fields in packed structures.
+        let ident = event.0.ident;
+        let data = event.0.data;
+        let udata = event.0.udata;
+        f.debug_struct("kevent")
+            .field("ident", &ident)
+            .field("filter", &FilterDetails(event.0.filter))
+            .field("flags", &FlagsDetails(event.0.flags))
+            .field("fflags", &FflagsDetails(event.0.fflags))
+            .field("data", &data)
+            .field("udata", &udata)
+            .finish()
+    }
+}
+
+// No special requirement from the implementation around waking.
+pub(crate) use crate::sys::unix::waker::Waker;
+
+cfg_io_source! {
+    mod stateless_io_source;
+    pub(crate) use stateless_io_source::IoSourceState;
+}
+
+#[test]
+#[cfg(feature = "os-ext")]
+fn does_not_register_rw() {
+    use crate::unix::SourceFd;
+    use crate::{Poll, Token};
+
+    let kq = unsafe { libc::kqueue() };
+    let mut kqf = SourceFd(&kq);
+    let poll = Poll::new().unwrap();
+
+    // Registering kqueue fd will fail if write is requested (On anything but
+    // some versions of macOS).
+    poll.registry()
+        .register(&mut kqf, Token(1234), Interest::READABLE)
+        .unwrap();
+}

vendor/mio/src/sys/unix/selector/poll.rs

@@ -0,0 +1,753 @@
+// This implementation is based on the one in the `polling` crate.
+// Thanks to https://github.com/Kestrer for the original implementation!
+// Permission to use this code has been granted by original author:
+// https://github.com/tokio-rs/mio/pull/1602#issuecomment-1218441031
+
+use std::collections::HashMap;
+use std::fmt::{Debug, Formatter};
+#[cfg(not(target_os = "hermit"))]
+use std::os::fd::{AsRawFd, RawFd};
+// TODO: once <https://github.com/rust-lang/rust/issues/126198> is fixed this
+// can use `std::os::fd` and be merged with the above.
+#[cfg(target_os = "hermit")]
+use std::os::hermit::io::{AsRawFd, RawFd};
+use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
+use std::sync::{Arc, Condvar, Mutex};
+use std::time::Duration;
+use std::{cmp, fmt, io};
+
+use crate::sys::unix::waker::Waker as WakerInternal;
+use crate::{Interest, Token};
+
+/// Unique id for use as `SelectorId`.
+#[cfg(debug_assertions)]
+static NEXT_ID: AtomicUsize = AtomicUsize::new(1);
+
+#[derive(Debug)]
+pub struct Selector {
+    state: Arc<SelectorState>,
+}
+
+impl Selector {
+    pub fn new() -> io::Result<Selector> {
+        let state = SelectorState::new()?;
+
+        Ok(Selector {
+            state: Arc::new(state),
+        })
+    }
+
+    pub fn try_clone(&self) -> io::Result<Selector> {
+        let state = self.state.clone();
+
+        Ok(Selector { state })
+    }
+
+    pub fn select(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<()> {
+        self.state.select(events, timeout)
+    }
+
+    pub fn register(&self, fd: RawFd, token: Token, interests: Interest) -> io::Result<()> {
+        self.state.register(fd, token, interests)
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn register_internal(
+        &self,
+        fd: RawFd,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<Arc<RegistrationRecord>> {
+        self.state.register_internal(fd, token, interests)
+    }
+
+    cfg_any_os_ext! {
+    pub fn reregister(&self, fd: RawFd, token: Token, interests: Interest) -> io::Result<()> {
+        self.state.reregister(fd, token, interests)
+    }
+
+    pub fn deregister(&self, fd: RawFd) -> io::Result<()> {
+        self.state.deregister(fd)
+    }
+    }
+
+    pub fn wake(&self, token: Token) -> io::Result<()> {
+        self.state.wake(token)
+    }
+
+    cfg_io_source! {
+        #[cfg(debug_assertions)]
+        pub fn id(&self) -> usize {
+            self.state.id
+        }
+    }
+}
+
+/// Interface to poll.
+#[derive(Debug)]
+struct SelectorState {
+    /// File descriptors to poll.
+    fds: Mutex<Fds>,
+
+    /// File descriptors which will be removed before the next poll call.
+    ///
+    /// When a file descriptor is deregistered while a poll is running, we need to filter
+    /// out all removed descriptors after that poll is finished running.
+    pending_removal: Mutex<Vec<RawFd>>,
+
+    /// Token associated with Waker that have recently asked to wake.  This will
+    /// cause a synthetic behaviour where on any wakeup we add all pending tokens
+    /// to the list of emitted events.
+    pending_wake_token: Mutex<Option<Token>>,
+
+    /// Data is written to this to wake up the current instance of `wait`, which can occur when the
+    /// user notifies it (in which case `notified` would have been set) or when an operation needs
+    /// to occur (in which case `waiting_operations` would have been incremented).
+    notify_waker: WakerInternal,
+
+    /// The number of operations (`add`, `modify` or `delete`) that are currently waiting on the
+    /// mutex to become free. When this is nonzero, `wait` must be suspended until it reaches zero
+    /// again.
+    waiting_operations: AtomicUsize,
+    /// The condition variable that gets notified when `waiting_operations` reaches zero or
+    /// `notified` becomes true.
+    ///
+    /// This is used with the `fds` mutex.
+    operations_complete: Condvar,
+
+    /// This selectors id.
+    #[cfg(debug_assertions)]
+    #[allow(dead_code)]
+    id: usize,
+}
+
+/// The file descriptors to poll in a `Poller`.
+#[derive(Debug, Clone)]
+struct Fds {
+    /// The list of `pollfds` taken by poll.
+    ///
+    /// The first file descriptor is always present and is used to notify the poller.
+    poll_fds: Vec<PollFd>,
+    /// The map of each file descriptor to data associated with it. This does not include the file
+    /// descriptors created by the internal notify waker.
+    fd_data: HashMap<RawFd, FdData>,
+}
+
+/// Transparent wrapper around `libc::pollfd`, used to support `Debug` derives without adding the
+/// `extra_traits` feature of `libc`.
+#[repr(transparent)]
+#[derive(Clone)]
+struct PollFd(libc::pollfd);
+
+impl Debug for PollFd {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        f.debug_struct("pollfd")
+            .field("fd", &self.0.fd)
+            .field("events", &self.0.events)
+            .field("revents", &self.0.revents)
+            .finish()
+    }
+}
+
+/// Data associated with a file descriptor in a poller.
+#[derive(Debug, Clone)]
+struct FdData {
+    /// The index into `poll_fds` this file descriptor is.
+    poll_fds_index: usize,
+    /// The key of the `Event` associated with this file descriptor.
+    token: Token,
+    /// Used to communicate with IoSourceState when we need to internally deregister
+    /// based on a closed fd.
+    shared_record: Arc<RegistrationRecord>,
+}
+
+impl SelectorState {
+    pub fn new() -> io::Result<SelectorState> {
+        let notify_waker = WakerInternal::new_unregistered()?;
+
+        Ok(Self {
+            fds: Mutex::new(Fds {
+                poll_fds: vec![PollFd(libc::pollfd {
+                    fd: notify_waker.as_raw_fd(),
+                    events: libc::POLLIN,
+                    revents: 0,
+                })],
+                fd_data: HashMap::new(),
+            }),
+            pending_removal: Mutex::new(Vec::new()),
+            pending_wake_token: Mutex::new(None),
+            notify_waker,
+            waiting_operations: AtomicUsize::new(0),
+            operations_complete: Condvar::new(),
+            #[cfg(debug_assertions)]
+            id: NEXT_ID.fetch_add(1, Ordering::Relaxed),
+        })
+    }
+
+    pub fn select(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<()> {
+        events.clear();
+
+        let mut fds = self.fds.lock().unwrap();
+
+        // Keep track of fds that receive POLLHUP or POLLERR (i.e. won't receive further
+        // events) and internally deregister them before they are externally deregister'd.  See
+        // IoSourceState below to track how the external deregister call will be handled
+        // when this state occurs.
+        let mut closed_raw_fds = Vec::new();
+
+        loop {
+            // Complete all current operations.
+            loop {
+                if self.waiting_operations.load(Ordering::SeqCst) == 0 {
+                    break;
+                }
+
+                fds = self.operations_complete.wait(fds).unwrap();
+            }
+
+            // Perform the poll.
+            trace!("Polling on {:?}", &fds);
+            let num_events = poll(&mut fds.poll_fds, timeout)?;
+            trace!("Poll finished: {:?}", &fds);
+
+            if num_events == 0 {
+                return Ok(());
+            }
+
+            let waker_events = fds.poll_fds[0].0.revents;
+            let notified = waker_events != 0;
+            let mut num_fd_events = if notified { num_events - 1 } else { num_events };
+
+            let pending_wake_token = self.pending_wake_token.lock().unwrap().take();
+
+            if notified {
+                self.notify_waker.ack_and_reset();
+                if pending_wake_token.is_some() {
+                    num_fd_events += 1;
+                }
+            }
+
+            // We now check whether this poll was performed with descriptors which were pending
+            // for removal and filter out any matching.
+            let mut pending_removal_guard = self.pending_removal.lock().unwrap();
+            let mut pending_removal = std::mem::replace(pending_removal_guard.as_mut(), Vec::new());
+            drop(pending_removal_guard);
+
+            // Store the events if there were any.
+            if num_fd_events > 0 {
+                let fds = &mut *fds;
+
+                events.reserve(num_fd_events);
+
+                // Add synthetic events we picked up from calls to wake()
+                if let Some(pending_wake_token) = pending_wake_token {
+                    events.push(Event {
+                        token: pending_wake_token,
+                        events: waker_events,
+                    });
+                }
+
+                for fd_data in fds.fd_data.values_mut() {
+                    let PollFd(poll_fd) = &mut fds.poll_fds[fd_data.poll_fds_index];
+
+                    if pending_removal.contains(&poll_fd.fd) {
+                        // Fd was removed while poll was running
+                        continue;
+                    }
+
+                    if poll_fd.revents != 0 {
+                        // Store event
+                        events.push(Event {
+                            token: fd_data.token,
+                            events: poll_fd.revents,
+                        });
+
+                        if poll_fd.revents & (libc::POLLHUP | libc::POLLERR) != 0 {
+                            pending_removal.push(poll_fd.fd);
+                            closed_raw_fds.push(poll_fd.fd);
+                        }
+
+                        // Remove the interest which just got triggered the IoSourceState's do_io
+                        // wrapper used with this selector will add back the interest using
+                        // reregister.
+                        poll_fd.events &= !poll_fd.revents;
+
+                        // Minor optimization to potentially avoid looping n times where n is the
+                        // number of input fds (i.e. we might loop between m and n times where m is
+                        // the number of fds with revents != 0).
+                        if events.len() == num_fd_events {
+                            break;
+                        }
+                    }
+                }
+
+                break; // No more polling.
+            }
+
+            // If we didn't break above it means we got woken up internally (for example for adding an fd), so we poll again.
+        }
+
+        drop(fds);
+        let _ = self.deregister_all(&closed_raw_fds);
+
+        Ok(())
+    }
+
+    pub fn register(&self, fd: RawFd, token: Token, interests: Interest) -> io::Result<()> {
+        self.register_internal(fd, token, interests).map(|_| ())
+    }
+
+    pub fn register_internal(
+        &self,
+        fd: RawFd,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<Arc<RegistrationRecord>> {
+        #[cfg(debug_assertions)]
+        if fd == self.notify_waker.as_raw_fd() {
+            return Err(io::Error::from(io::ErrorKind::InvalidInput));
+        }
+
+        // We must handle the unlikely case that the following order of operations happens:
+        //
+        // register(1 as RawFd)
+        // deregister(1 as RawFd)
+        // register(1 as RawFd)
+        // <poll happens>
+        //
+        // Fd's pending removal only get cleared when poll has been run. It is possible that
+        // between registering and deregistering and then _again_ registering the file descriptor
+        // poll never gets called, thus the fd stays stuck in the pending removal list.
+        //
+        // To avoid this scenario we remove an fd from pending removals when registering it.
+        let mut pending_removal = self.pending_removal.lock().unwrap();
+        if let Some(idx) = pending_removal.iter().position(|&pending| pending == fd) {
+            pending_removal.swap_remove(idx);
+        }
+        drop(pending_removal);
+
+        self.modify_fds(|fds| {
+            if fds.fd_data.contains_key(&fd) {
+                return Err(io::Error::new(
+                    io::ErrorKind::AlreadyExists,
+                    "I/O source already registered this `Registry` \
+                    (an old file descriptor might have been closed without deregistration)",
+                ));
+            }
+
+            let poll_fds_index = fds.poll_fds.len();
+            let record = Arc::new(RegistrationRecord::new());
+            fds.fd_data.insert(
+                fd,
+                FdData {
+                    poll_fds_index,
+                    token,
+                    shared_record: record.clone(),
+                },
+            );
+
+            fds.poll_fds.push(PollFd(libc::pollfd {
+                fd,
+                events: interests_to_poll(interests),
+                revents: 0,
+            }));
+
+            Ok(record)
+        })
+    }
+
+    cfg_any_os_ext! {
+    pub fn reregister(&self, fd: RawFd, token: Token, interests: Interest) -> io::Result<()> {
+        self.modify_fds(|fds| {
+            let data = fds.fd_data.get_mut(&fd).ok_or(io::ErrorKind::NotFound)?;
+            data.token = token;
+            let poll_fds_index = data.poll_fds_index;
+            fds.poll_fds[poll_fds_index].0.events = interests_to_poll(interests);
+
+            Ok(())
+        })
+    }
+
+    pub fn deregister(&self, fd: RawFd) -> io::Result<()> {
+        self.deregister_all(&[fd])
+            .map_err(|_| io::ErrorKind::NotFound)?;
+        Ok(())
+    }
+    }
+
+    /// Perform a modification on `fds`, interrupting the current caller of `wait` if it's running.
+    fn modify_fds<T>(&self, f: impl FnOnce(&mut Fds) -> T) -> T {
+        self.waiting_operations.fetch_add(1, Ordering::SeqCst);
+
+        // Wake up the current caller of `wait` if there is one.
+        let sent_notification = self.notify_waker.wake().is_ok();
+
+        let mut fds = self.fds.lock().unwrap();
+
+        // If there was no caller of `wait` our notification was not removed from the pipe.
+        if sent_notification {
+            self.notify_waker.ack_and_reset();
+        }
+
+        let res = f(&mut *fds);
+
+        if self.waiting_operations.fetch_sub(1, Ordering::SeqCst) == 1 {
+            self.operations_complete.notify_one();
+        }
+
+        res
+    }
+
+    /// Special optimized version of [Self::deregister] which handles multiple removals
+    /// at once.  Ok result if all removals were performed, Err if any entries
+    /// were not found.
+    fn deregister_all(&self, targets: &[RawFd]) -> Result<(), ()> {
+        if targets.is_empty() {
+            return Ok(());
+        }
+
+        let mut pending_removal = self.pending_removal.lock().unwrap();
+        pending_removal.extend(targets);
+        drop(pending_removal);
+
+        self.modify_fds(|fds| {
+            let mut all_successful = true;
+
+            for target in targets {
+                match fds.fd_data.remove(target).ok_or(()) {
+                    Ok(data) => {
+                        data.shared_record.mark_unregistered();
+                        fds.poll_fds.swap_remove(data.poll_fds_index);
+                        if let Some(swapped_pollfd) = fds.poll_fds.get(data.poll_fds_index) {
+                            fds.fd_data
+                                .get_mut(&swapped_pollfd.0.fd)
+                                .unwrap()
+                                .poll_fds_index = data.poll_fds_index;
+                        }
+                    }
+                    Err(_) => all_successful = false,
+                }
+            }
+
+            if all_successful {
+                Ok(())
+            } else {
+                Err(())
+            }
+        })
+    }
+
+    pub fn wake(&self, token: Token) -> io::Result<()> {
+        self.pending_wake_token.lock().unwrap().replace(token);
+        self.notify_waker.wake()
+    }
+}
+
+/// Shared record between IoSourceState and SelectorState that allows us to internally
+/// deregister partially or fully closed fds (i.e. when we get POLLHUP or PULLERR) without
+/// confusing IoSourceState and trying to deregister twice.  This isn't strictly
+/// required as technically deregister is idempotent but it is confusing
+/// when trying to debug behaviour as we get imbalanced calls to register/deregister and
+/// superfluous NotFound errors.
+#[derive(Debug)]
+pub(crate) struct RegistrationRecord {
+    is_unregistered: AtomicBool,
+}
+
+impl RegistrationRecord {
+    pub fn new() -> Self {
+        Self {
+            is_unregistered: AtomicBool::new(false),
+        }
+    }
+
+    pub fn mark_unregistered(&self) {
+        self.is_unregistered.store(true, Ordering::Relaxed);
+    }
+
+    #[allow(dead_code)]
+    pub fn is_registered(&self) -> bool {
+        !self.is_unregistered.load(Ordering::Relaxed)
+    }
+}
+
+#[cfg(target_os = "linux")]
+const POLLRDHUP: libc::c_short = libc::POLLRDHUP;
+#[cfg(not(target_os = "linux"))]
+const POLLRDHUP: libc::c_short = 0;
+
+const READ_EVENTS: libc::c_short = libc::POLLIN | POLLRDHUP;
+
+const WRITE_EVENTS: libc::c_short = libc::POLLOUT;
+
+const PRIORITY_EVENTS: libc::c_short = libc::POLLPRI;
+
+/// Get the input poll events for the given event.
+fn interests_to_poll(interest: Interest) -> libc::c_short {
+    let mut kind = 0;
+
+    if interest.is_readable() {
+        kind |= READ_EVENTS;
+    }
+
+    if interest.is_writable() {
+        kind |= WRITE_EVENTS;
+    }
+
+    if interest.is_priority() {
+        kind |= PRIORITY_EVENTS;
+    }
+
+    kind
+}
+
+/// Helper function to call poll.
+fn poll(fds: &mut [PollFd], timeout: Option<Duration>) -> io::Result<usize> {
+    loop {
+        // A bug in kernels < 2.6.37 makes timeouts larger than LONG_MAX / CONFIG_HZ
+        // (approx. 30 minutes with CONFIG_HZ=1200) effectively infinite on 32 bits
+        // architectures. The magic number is the same constant used by libuv.
+        #[cfg(target_pointer_width = "32")]
+        const MAX_SAFE_TIMEOUT: u128 = 1789569;
+        #[cfg(not(target_pointer_width = "32"))]
+        const MAX_SAFE_TIMEOUT: u128 = libc::c_int::MAX as u128;
+
+        let timeout = timeout
+            .map(|to| {
+                // `Duration::as_millis` truncates, so round up. This avoids
+                // turning sub-millisecond timeouts into a zero timeout, unless
+                // the caller explicitly requests that by specifying a zero
+                // timeout.
+                let to_ms = to
+                    .checked_add(Duration::from_nanos(999_999))
+                    .unwrap_or(to)
+                    .as_millis();
+                cmp::min(MAX_SAFE_TIMEOUT, to_ms) as libc::c_int
+            })
+            .unwrap_or(-1);
+
+        let res = syscall!(poll(
+            fds.as_mut_ptr() as *mut libc::pollfd,
+            fds.len() as libc::nfds_t,
+            timeout,
+        ));
+
+        match res {
+            Ok(num_events) => break Ok(num_events as usize),
+            // poll returns EAGAIN if we can retry it.
+            Err(e) if e.raw_os_error() == Some(libc::EAGAIN) => continue,
+            Err(e) => return Err(e),
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Event {
+    token: Token,
+    events: libc::c_short,
+}
+
+pub type Events = Vec<Event>;
+
+pub mod event {
+    use std::fmt;
+
+    use crate::sys::Event;
+    use crate::Token;
+
+    use super::POLLRDHUP;
+
+    pub fn token(event: &Event) -> Token {
+        event.token
+    }
+
+    pub fn is_readable(event: &Event) -> bool {
+        (event.events & libc::POLLIN) != 0 || (event.events & libc::POLLPRI) != 0
+    }
+
+    pub fn is_writable(event: &Event) -> bool {
+        (event.events & libc::POLLOUT) != 0
+    }
+
+    pub fn is_error(event: &Event) -> bool {
+        (event.events & libc::POLLERR) != 0
+    }
+
+    pub fn is_read_closed(event: &Event) -> bool {
+        // Both halves of the socket have closed
+        (event.events & libc::POLLHUP) != 0
+            // Socket has received FIN or called shutdown(SHUT_RD)
+            || (event.events & POLLRDHUP) != 0
+    }
+
+    pub fn is_write_closed(event: &Event) -> bool {
+        // Both halves of the socket have closed
+        (event.events & libc::POLLHUP) != 0
+            // Unix pipe write end has closed
+            || ((event.events & libc::POLLOUT) != 0 && (event.events & libc::POLLERR) != 0)
+            // The other side (read end) of a Unix pipe has closed.
+            || (event.events == libc::POLLERR)
+    }
+
+    pub fn is_priority(event: &Event) -> bool {
+        (event.events & libc::POLLPRI) != 0
+    }
+
+    pub fn is_aio(_: &Event) -> bool {
+        // Not supported in the kernel, only in libc.
+        false
+    }
+
+    pub fn is_lio(_: &Event) -> bool {
+        // Not supported.
+        false
+    }
+
+    pub fn debug_details(f: &mut fmt::Formatter<'_>, event: &Event) -> fmt::Result {
+        #[allow(clippy::trivially_copy_pass_by_ref)]
+        fn check_events(got: &libc::c_short, want: &libc::c_short) -> bool {
+            (*got & want) != 0
+        }
+        debug_detail!(
+            EventsDetails(libc::c_short),
+            check_events,
+            libc::POLLIN,
+            libc::POLLPRI,
+            libc::POLLOUT,
+            libc::POLLRDNORM,
+            libc::POLLRDBAND,
+            libc::POLLWRNORM,
+            libc::POLLWRBAND,
+            libc::POLLERR,
+            libc::POLLHUP,
+        );
+
+        f.debug_struct("poll_event")
+            .field("token", &event.token)
+            .field("events", &EventsDetails(event.events))
+            .finish()
+    }
+}
+
+#[derive(Debug)]
+pub(crate) struct Waker {
+    selector: Selector,
+    token: Token,
+}
+
+impl Waker {
+    pub(crate) fn new(selector: &Selector, token: Token) -> io::Result<Waker> {
+        Ok(Waker {
+            selector: selector.try_clone()?,
+            token,
+        })
+    }
+
+    pub(crate) fn wake(&self) -> io::Result<()> {
+        self.selector.wake(self.token)
+    }
+}
+
+cfg_io_source! {
+    use crate::Registry;
+
+    struct InternalState {
+        selector: Selector,
+        token: Token,
+        interests: Interest,
+        fd: RawFd,
+        shared_record: Arc<RegistrationRecord>,
+    }
+
+    impl Drop for InternalState {
+        fn drop(&mut self) {
+            if self.shared_record.is_registered() {
+                let _ = self.selector.deregister(self.fd);
+            }
+        }
+    }
+
+    pub(crate) struct IoSourceState {
+        inner: Option<Box<InternalState>>,
+    }
+
+    impl IoSourceState {
+        pub fn new() -> IoSourceState {
+            IoSourceState { inner: None }
+        }
+
+        pub fn do_io<T, F, R>(&self, f: F, io: &T) -> io::Result<R>
+        where
+        F: FnOnce(&T) -> io::Result<R>,
+        {
+            let result = f(io);
+
+            if let Err(err) = &result {
+                if err.kind() == io::ErrorKind::WouldBlock {
+                    self.inner.as_ref().map_or(Ok(()), |state| {
+                        state
+                        .selector
+                        .reregister(state.fd, state.token, state.interests)
+                    })?;
+                }
+            }
+
+            result
+        }
+
+        pub fn register(
+            &mut self,
+            registry: &Registry,
+            token: Token,
+            interests: Interest,
+            fd: RawFd,
+        ) -> io::Result<()> {
+            if self.inner.is_some() {
+                Err(io::ErrorKind::AlreadyExists.into())
+            } else {
+                let selector = registry.selector().try_clone()?;
+
+                selector.register_internal(fd, token, interests).map(move |shared_record| {
+                    let state = InternalState {
+                        selector,
+                        token,
+                        interests,
+                        fd,
+                        shared_record,
+                    };
+
+                    self.inner = Some(Box::new(state));
+                })
+            }
+        }
+
+        pub fn reregister(
+            &mut self,
+            registry: &Registry,
+            token: Token,
+            interests: Interest,
+            fd: RawFd,
+        ) -> io::Result<()> {
+            match self.inner.as_mut() {
+                Some(state) => registry
+                .selector()
+                .reregister(fd, token, interests)
+                .map(|()| {
+                    state.token = token;
+                    state.interests = interests;
+                }),
+                None => Err(io::ErrorKind::NotFound.into()),
+            }
+        }
+
+        pub fn deregister(&mut self, registry: &Registry, fd: RawFd) -> io::Result<()> {
+            if let Some(state) = self.inner.take() {
+                // Marking unregistered will short circuit the drop behaviour of calling
+                // deregister so the call to deregister below is strictly required.
+                state.shared_record.mark_unregistered();
+            }
+
+            registry.selector().deregister(fd)
+        }
+    }
+}

vendor/mio/src/sys/unix/selector/stateless_io_source.rs

@@ -0,0 +1,50 @@
+//! Both `kqueue(2)` and `epoll(2)` don't need to hold any user space state.
+
+use std::io;
+use std::os::fd::RawFd;
+
+use crate::{Interest, Registry, Token};
+
+pub(crate) struct IoSourceState;
+
+impl IoSourceState {
+    pub(crate) fn new() -> IoSourceState {
+        IoSourceState
+    }
+
+    pub(crate) fn do_io<T, F, R>(&self, f: F, io: &T) -> io::Result<R>
+    where
+        F: FnOnce(&T) -> io::Result<R>,
+    {
+        // We don't hold state, so we can just call the function and
+        // return.
+        f(io)
+    }
+
+    pub(crate) fn register(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+        fd: RawFd,
+    ) -> io::Result<()> {
+        // Pass through, we don't have any state.
+        registry.selector().register(fd, token, interests)
+    }
+
+    pub(crate) fn reregister(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+        fd: RawFd,
+    ) -> io::Result<()> {
+        // Pass through, we don't have any state.
+        registry.selector().reregister(fd, token, interests)
+    }
+
+    pub(crate) fn deregister(&mut self, registry: &Registry, fd: RawFd) -> io::Result<()> {
+        // Pass through, we don't have any state.
+        registry.selector().deregister(fd)
+    }
+}

vendor/mio/src/sys/unix/sourcefd.rs

@@ -0,0 +1,121 @@
+use std::io;
+#[cfg(not(target_os = "hermit"))]
+use std::os::fd::RawFd;
+// TODO: once <https://github.com/rust-lang/rust/issues/126198> is fixed this
+// can use `std::os::fd` and be merged with the above.
+#[cfg(target_os = "hermit")]
+use std::os::hermit::io::RawFd;
+
+use crate::{event, Interest, Registry, Token};
+
+/// Adapter for [`RawFd`] providing an [`event::Source`] implementation.
+///
+/// `SourceFd` enables registering any type with an FD with [`Poll`].
+///
+/// While only implementations for TCP and UDP are provided, Mio supports
+/// registering any FD that can be registered with the underlying OS selector.
+/// `SourceFd` provides the necessary bridge.
+///
+/// Note that `SourceFd` takes a `&RawFd`. This is because `SourceFd` **does
+/// not** take ownership of the FD. Specifically, it will not manage any
+/// lifecycle related operations, such as closing the FD on drop. It is expected
+/// that the `SourceFd` is constructed right before a call to
+/// [`Registry::register`]. See the examples for more detail.
+///
+/// [`event::Source`]: ../event/trait.Source.html
+/// [`Poll`]: ../struct.Poll.html
+/// [`Registry::register`]: ../struct.Registry.html#method.register
+///
+/// # Examples
+///
+/// Basic usage.
+///
+#[cfg_attr(
+    all(feature = "os-poll", feature = "net", feature = "os-ext"),
+    doc = "```"
+)]
+#[cfg_attr(
+    not(all(feature = "os-poll", feature = "net", feature = "os-ext")),
+    doc = "```ignore"
+)]
+/// # use std::error::Error;
+/// # fn main() -> Result<(), Box<dyn Error>> {
+/// use mio::{Interest, Poll, Token};
+/// use mio::unix::SourceFd;
+///
+/// use std::os::fd::AsRawFd;
+/// use std::net::TcpListener;
+///
+/// // Bind a std listener
+/// let listener = TcpListener::bind("127.0.0.1:0")?;
+///
+/// let poll = Poll::new()?;
+///
+/// // Register the listener
+/// poll.registry().register(
+///     &mut SourceFd(&listener.as_raw_fd()),
+///     Token(0),
+///     Interest::READABLE)?;
+/// #     Ok(())
+/// # }
+/// ```
+///
+/// Implementing [`event::Source`] for a custom type backed by a [`RawFd`].
+///
+#[cfg_attr(all(feature = "os-poll", feature = "os-ext"), doc = "```")]
+#[cfg_attr(not(all(feature = "os-poll", feature = "os-ext")), doc = "```ignore")]
+/// use mio::{event, Interest, Registry, Token};
+/// use mio::unix::SourceFd;
+///
+/// use std::os::fd::RawFd;
+/// use std::io;
+///
+/// # #[allow(dead_code)]
+/// pub struct MyIo {
+///     fd: RawFd,
+/// }
+///
+/// impl event::Source for MyIo {
+///     fn register(&mut self, registry: &Registry, token: Token, interests: Interest)
+///         -> io::Result<()>
+///     {
+///         SourceFd(&self.fd).register(registry, token, interests)
+///     }
+///
+///     fn reregister(&mut self, registry: &Registry, token: Token, interests: Interest)
+///         -> io::Result<()>
+///     {
+///         SourceFd(&self.fd).reregister(registry, token, interests)
+///     }
+///
+///     fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
+///         SourceFd(&self.fd).deregister(registry)
+///     }
+/// }
+/// ```
+#[derive(Debug)]
+pub struct SourceFd<'a>(pub &'a RawFd);
+
+impl<'a> event::Source for SourceFd<'a> {
+    fn register(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        registry.selector().register(*self.0, token, interests)
+    }
+
+    fn reregister(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        registry.selector().reregister(*self.0, token, interests)
+    }
+
+    fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
+        registry.selector().deregister(*self.0)
+    }
+}

vendor/mio/src/sys/unix/tcp.rs

@@ -0,0 +1,135 @@
+use std::io;
+use std::mem::{size_of, MaybeUninit};
+use std::net::{self, SocketAddr};
+#[cfg(not(target_os = "hermit"))]
+use std::os::fd::{AsRawFd, FromRawFd};
+// TODO: once <https://github.com/rust-lang/rust/issues/126198> is fixed this
+// can use `std::os::fd` and be merged with the above.
+#[cfg(target_os = "hermit")]
+use std::os::hermit::io::{AsRawFd, FromRawFd};
+
+use crate::sys::unix::net::{new_socket, socket_addr, to_socket_addr};
+
+pub(crate) fn new_for_addr(address: SocketAddr) -> io::Result<libc::c_int> {
+    let domain = match address {
+        SocketAddr::V4(_) => libc::AF_INET,
+        SocketAddr::V6(_) => libc::AF_INET6,
+    };
+    new_socket(domain, libc::SOCK_STREAM)
+}
+
+pub(crate) fn bind(socket: &net::TcpListener, addr: SocketAddr) -> io::Result<()> {
+    let (raw_addr, raw_addr_length) = socket_addr(&addr);
+    syscall!(bind(socket.as_raw_fd(), raw_addr.as_ptr(), raw_addr_length))?;
+    Ok(())
+}
+
+pub(crate) fn connect(socket: &net::TcpStream, addr: SocketAddr) -> io::Result<()> {
+    let (raw_addr, raw_addr_length) = socket_addr(&addr);
+
+    match syscall!(connect(
+        socket.as_raw_fd(),
+        raw_addr.as_ptr(),
+        raw_addr_length
+    )) {
+        Err(err) if err.raw_os_error() != Some(libc::EINPROGRESS) => Err(err),
+        _ => Ok(()),
+    }
+}
+
+pub(crate) fn listen(socket: &net::TcpListener, backlog: i32) -> io::Result<()> {
+    syscall!(listen(socket.as_raw_fd(), backlog))?;
+    Ok(())
+}
+
+pub(crate) fn set_reuseaddr(socket: &net::TcpListener, reuseaddr: bool) -> io::Result<()> {
+    let val: libc::c_int = i32::from(reuseaddr);
+    syscall!(setsockopt(
+        socket.as_raw_fd(),
+        libc::SOL_SOCKET,
+        libc::SO_REUSEADDR,
+        &val as *const libc::c_int as *const libc::c_void,
+        size_of::<libc::c_int>() as libc::socklen_t,
+    ))?;
+    Ok(())
+}
+
+pub(crate) fn accept(listener: &net::TcpListener) -> io::Result<(net::TcpStream, SocketAddr)> {
+    let mut addr: MaybeUninit<libc::sockaddr_storage> = MaybeUninit::uninit();
+    let mut length = size_of::<libc::sockaddr_storage>() as libc::socklen_t;
+
+    // On platforms that support it we can use `accept4(2)` to set `NONBLOCK`
+    // and `CLOEXEC` in the call to accept the connection.
+    #[cfg(any(
+        // Android x86's seccomp profile forbids calls to `accept4(2)`
+        // See https://github.com/tokio-rs/mio/issues/1445 for details
+        all(not(target_arch="x86"), target_os = "android"),
+        target_os = "dragonfly",
+        target_os = "freebsd",
+        target_os = "fuchsia",
+        target_os = "hurd",
+        target_os = "illumos",
+        target_os = "linux",
+        target_os = "netbsd",
+        target_os = "openbsd",
+        target_os = "solaris",
+        target_os = "cygwin",
+    ))]
+    let stream = {
+        syscall!(accept4(
+            listener.as_raw_fd(),
+            addr.as_mut_ptr() as *mut _,
+            &mut length,
+            libc::SOCK_CLOEXEC | libc::SOCK_NONBLOCK,
+        ))
+        .map(|socket| unsafe { net::TcpStream::from_raw_fd(socket) })
+    }?;
+
+    // But not all platforms have the `accept4(2)` call. Luckily BSD (derived)
+    // OSs inherit the non-blocking flag from the listener, so we just have to
+    // set `CLOEXEC`.
+    #[cfg(any(
+        target_os = "aix",
+        target_os = "haiku",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "redox",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos",
+        target_os = "espidf",
+        target_os = "vita",
+        target_os = "hermit",
+        target_os = "nto",
+        all(target_arch = "x86", target_os = "android"),
+    ))]
+    let stream = {
+        syscall!(accept(
+            listener.as_raw_fd(),
+            addr.as_mut_ptr() as *mut _,
+            &mut length
+        ))
+        .map(|socket| unsafe { net::TcpStream::from_raw_fd(socket) })
+        .and_then(|s| {
+            #[cfg(not(any(target_os = "espidf", target_os = "vita")))]
+            syscall!(fcntl(s.as_raw_fd(), libc::F_SETFD, libc::FD_CLOEXEC))?;
+
+            // See https://github.com/tokio-rs/mio/issues/1450
+            #[cfg(any(
+                all(target_arch = "x86", target_os = "android"),
+                target_os = "aix",
+                target_os = "espidf",
+                target_os = "vita",
+                target_os = "hermit",
+                target_os = "nto",
+            ))]
+            syscall!(fcntl(s.as_raw_fd(), libc::F_SETFL, libc::O_NONBLOCK))?;
+
+            Ok(s)
+        })
+    }?;
+
+    // This is safe because `accept` calls above ensures the address
+    // initialised.
+    unsafe { to_socket_addr(addr.as_ptr()) }.map(|addr| (stream, addr))
+}

vendor/mio/src/sys/unix/udp.rs

@@ -0,0 +1,36 @@
+use std::io;
+use std::mem;
+use std::net::{self, SocketAddr};
+#[cfg(not(target_os = "hermit"))]
+use std::os::fd::{AsRawFd, FromRawFd};
+// TODO: once <https://github.com/rust-lang/rust/issues/126198> is fixed this
+// can use `std::os::fd` and be merged with the above.
+#[cfg(target_os = "hermit")]
+use std::os::hermit::io::{AsRawFd, FromRawFd};
+
+use crate::sys::unix::net::{new_ip_socket, socket_addr};
+
+pub fn bind(addr: SocketAddr) -> io::Result<net::UdpSocket> {
+    let fd = new_ip_socket(addr, libc::SOCK_DGRAM)?;
+    let socket = unsafe { net::UdpSocket::from_raw_fd(fd) };
+
+    let (raw_addr, raw_addr_length) = socket_addr(&addr);
+    syscall!(bind(fd, raw_addr.as_ptr(), raw_addr_length))?;
+
+    Ok(socket)
+}
+
+pub(crate) fn only_v6(socket: &net::UdpSocket) -> io::Result<bool> {
+    let mut optval: libc::c_int = 0;
+    let mut optlen = mem::size_of::<libc::c_int>() as libc::socklen_t;
+
+    syscall!(getsockopt(
+        socket.as_raw_fd(),
+        libc::IPPROTO_IPV6,
+        libc::IPV6_V6ONLY,
+        &mut optval as *mut _ as *mut _,
+        &mut optlen,
+    ))?;
+
+    Ok(optval != 0)
+}

vendor/mio/src/sys/unix/uds/datagram.rs

@@ -0,0 +1,25 @@
+use std::io;
+use std::os::fd::{AsRawFd, FromRawFd};
+use std::os::unix::net::{self, SocketAddr};
+
+use crate::sys::unix::net::new_socket;
+use crate::sys::unix::uds::unix_addr;
+
+pub(crate) fn bind_addr(address: &SocketAddr) -> io::Result<net::UnixDatagram> {
+    let socket = unbound()?;
+
+    let (unix_address, addrlen) = unix_addr(address);
+    let sockaddr = &unix_address as *const libc::sockaddr_un as *const libc::sockaddr;
+    syscall!(bind(socket.as_raw_fd(), sockaddr, addrlen))?;
+
+    Ok(socket)
+}
+
+pub(crate) fn unbound() -> io::Result<net::UnixDatagram> {
+    let fd = new_socket(libc::AF_UNIX, libc::SOCK_DGRAM)?;
+    Ok(unsafe { net::UnixDatagram::from_raw_fd(fd) })
+}
+
+pub(crate) fn pair() -> io::Result<(net::UnixDatagram, net::UnixDatagram)> {
+    super::pair(libc::SOCK_DGRAM)
+}

vendor/mio/src/sys/unix/uds/listener.rs

@@ -0,0 +1,122 @@
+use std::ffi::OsStr;
+use std::os::fd::{AsRawFd, FromRawFd};
+use std::os::unix::ffi::OsStrExt;
+use std::os::unix::net::{self, SocketAddr};
+use std::path::Path;
+use std::{io, mem};
+
+use crate::net::UnixStream;
+use crate::sys::unix::net::new_socket;
+use crate::sys::unix::uds::{path_offset, unix_addr};
+use crate::sys::LISTEN_BACKLOG_SIZE;
+
+pub(crate) fn bind_addr(address: &SocketAddr) -> io::Result<net::UnixListener> {
+    let fd = new_socket(libc::AF_UNIX, libc::SOCK_STREAM)?;
+    let socket = unsafe { net::UnixListener::from_raw_fd(fd) };
+
+    let (unix_address, addrlen) = unix_addr(address);
+    let sockaddr = &unix_address as *const libc::sockaddr_un as *const libc::sockaddr;
+    syscall!(bind(fd, sockaddr, addrlen))?;
+    syscall!(listen(fd, LISTEN_BACKLOG_SIZE))?;
+
+    Ok(socket)
+}
+
+pub(crate) fn accept(listener: &net::UnixListener) -> io::Result<(UnixStream, SocketAddr)> {
+    // SAFETY: `libc::sockaddr_un` zero filled is properly initialized.
+    //
+    // `0` is a valid value for `sockaddr_un::sun_family`; it is
+    // `libc::AF_UNSPEC`.
+    //
+    // `[0; 108]` is a valid value for `sockaddr_un::sun_path`; it begins an
+    // abstract path.
+    let mut sockaddr = unsafe { mem::zeroed::<libc::sockaddr_un>() };
+
+    let mut socklen = mem::size_of_val(&sockaddr) as libc::socklen_t;
+
+    #[cfg(not(any(
+        target_os = "aix",
+        target_os = "haiku",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "netbsd",
+        target_os = "redox",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos",
+        target_os = "espidf",
+        target_os = "vita",
+        target_os = "nto",
+        // Android x86's seccomp profile forbids calls to `accept4(2)`
+        // See https://github.com/tokio-rs/mio/issues/1445 for details
+        all(target_arch = "x86", target_os = "android"),
+    )))]
+    let socket = {
+        let flags = libc::SOCK_NONBLOCK | libc::SOCK_CLOEXEC;
+        syscall!(accept4(
+            listener.as_raw_fd(),
+            &mut sockaddr as *mut libc::sockaddr_un as *mut libc::sockaddr,
+            &mut socklen,
+            flags
+        ))
+        .map(|socket| unsafe { net::UnixStream::from_raw_fd(socket) })
+    };
+
+    #[cfg(any(
+        target_os = "aix",
+        target_os = "haiku",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "netbsd",
+        target_os = "redox",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos",
+        target_os = "espidf",
+        target_os = "vita",
+        target_os = "nto",
+        all(target_arch = "x86", target_os = "android")
+    ))]
+    let socket = syscall!(accept(
+        listener.as_raw_fd(),
+        &mut sockaddr as *mut libc::sockaddr_un as *mut libc::sockaddr,
+        &mut socklen,
+    ))
+    .and_then(|socket| {
+        // Ensure the socket is closed if either of the `fcntl` calls
+        // error below.
+        let s = unsafe { net::UnixStream::from_raw_fd(socket) };
+        #[cfg(not(any(target_os = "espidf", target_os = "vita")))]
+        syscall!(fcntl(socket, libc::F_SETFD, libc::FD_CLOEXEC))?;
+
+        // See https://github.com/tokio-rs/mio/issues/1450
+        #[cfg(any(
+            all(target_arch = "x86", target_os = "android"),
+            target_os = "espidf",
+            target_os = "vita",
+            target_os = "nto",
+        ))]
+        syscall!(fcntl(socket, libc::F_SETFL, libc::O_NONBLOCK))?;
+
+        Ok(s)
+    });
+
+    let socket = socket.map(UnixStream::from_std)?;
+
+    #[allow(unused_mut)] // See below.
+    let mut path_len = socklen as usize - path_offset(&sockaddr);
+    // On FreeBSD and Darwin, it returns a length of 14/16, but an unnamed (all
+    // zero) address. Map that to a length of 0 to match other OS.
+    if sockaddr.sun_path[0] == 0 {
+        path_len = 0;
+    }
+    // SAFETY: going from i8 to u8 is fine in this context.
+    let mut path =
+        unsafe { &*(&sockaddr.sun_path[..path_len] as *const [libc::c_char] as *const [u8]) };
+    // Remove last null as `SocketAddr::from_pathname` doesn't accept it.
+    if let Some(0) = path.last() {
+        path = &path[..path.len() - 1];
+    }
+    let address = SocketAddr::from_pathname(Path::new(OsStr::from_bytes(path)))?;
+    Ok((socket, address))
+}

vendor/mio/src/sys/unix/uds/mod.rs

@@ -0,0 +1,177 @@
+#[cfg(target_os = "android")]
+use std::os::android::net::SocketAddrExt;
+#[cfg(target_os = "linux")]
+use std::os::linux::net::SocketAddrExt;
+use std::os::unix::ffi::OsStrExt;
+use std::os::unix::io::FromRawFd;
+use std::os::unix::net::SocketAddr;
+use std::{io, mem, ptr};
+
+pub(crate) mod datagram;
+pub(crate) mod listener;
+pub(crate) mod stream;
+
+const UNNAMED_ADDRESS: &[u8] = &[];
+
+/// Get the `sun_path` field offset of `sockaddr_un` for the target OS.
+///
+/// On Linux, this function equates to the same value as
+/// `size_of::<sa_family_t>()`, but some other implementations include
+/// other fields before `sun_path`, so the expression more portably
+/// describes the size of the address structure.
+fn path_offset(sockaddr: &libc::sockaddr_un) -> usize {
+    let base = sockaddr as *const _ as usize;
+    let path = &sockaddr.sun_path as *const _ as usize;
+    path - base
+}
+
+/// Converts a Rust `SocketAddr` into the system representation.
+fn unix_addr(address: &SocketAddr) -> (libc::sockaddr_un, libc::socklen_t) {
+    // SAFETY: `libc::sockaddr_un` zero filled is properly initialized.
+    //
+    // `0` is a valid value for `sockaddr_un::sun_family`; it is
+    // `libc::AF_UNSPEC`.
+    //
+    // `[0; 108]` is a valid value for `sockaddr_un::sun_path`; it begins an
+    // abstract path.
+    let mut sockaddr = unsafe { mem::zeroed::<libc::sockaddr_un>() };
+
+    sockaddr.sun_family = libc::AF_UNIX as libc::sa_family_t;
+
+    #[allow(unused_mut)] // Only used with abstract namespaces.
+    let mut offset = 0;
+    let addr = match address.as_pathname() {
+        Some(path) => path.as_os_str().as_bytes(),
+        #[cfg(any(target_os = "android", target_os = "linux"))]
+        None => match address.as_abstract_name() {
+            Some(name) => {
+                offset += 1;
+                name
+            }
+            None => UNNAMED_ADDRESS,
+        },
+        #[cfg(not(any(target_os = "android", target_os = "linux")))]
+        None => UNNAMED_ADDRESS,
+    };
+
+    // SAFETY: `addr` and `sockaddr.sun_path` are not overlapping and both point
+    // to valid memory.
+    // SAFETY: since `addr` is a valid Unix address, it must not be larger than
+    // `SUN_LEN` bytes, thus we won't overwrite the size of sockaddr.sun_path.
+    // SAFETY: null byte is already written because we zeroed the address above.
+    debug_assert!(offset + addr.len() <= sockaddr.sun_path.len());
+    unsafe {
+        ptr::copy_nonoverlapping(
+            addr.as_ptr(),
+            sockaddr.sun_path.as_mut_ptr().add(offset).cast(),
+            addr.len(),
+        )
+    };
+
+    let mut addrlen = path_offset(&sockaddr) + addr.len();
+    // +1 for null byte at the end of the path, not needed for abstract
+    // namespaces (which start with a null byte).
+    match addr.first() {
+        Some(&0) | None => {}
+        Some(_) => addrlen += 1,
+    }
+
+    // SAFETY: the length is fine to cast to `socklen_t` as it's 32 bits and the
+    // address can be at most `SUN_LEN` bytes.
+    (sockaddr, addrlen as _)
+}
+
+fn pair<T>(flags: libc::c_int) -> io::Result<(T, T)>
+where
+    T: FromRawFd,
+{
+    #[cfg(not(any(
+        target_os = "aix",
+        target_os = "haiku",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "nto",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos",
+        target_os = "espidf",
+        target_os = "vita",
+    )))]
+    let flags = flags | libc::SOCK_NONBLOCK | libc::SOCK_CLOEXEC;
+
+    let mut fds = [-1; 2];
+    syscall!(socketpair(libc::AF_UNIX, flags, 0, fds.as_mut_ptr()))?;
+    let pair = unsafe { (T::from_raw_fd(fds[0]), T::from_raw_fd(fds[1])) };
+
+    // Darwin (and others) doesn't have SOCK_NONBLOCK or SOCK_CLOEXEC.
+    //
+    // In order to set those flags, additional `fcntl` sys calls must be
+    // performed. If a `fnctl` fails after the sockets have been created,
+    // the file descriptors will leak. Creating `pair` above ensures that if
+    // there is an error, the file descriptors are closed.
+    #[cfg(any(
+        target_os = "aix",
+        target_os = "haiku",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "nto",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos",
+        target_os = "espidf",
+        target_os = "vita",
+    ))]
+    {
+        syscall!(fcntl(fds[0], libc::F_SETFL, libc::O_NONBLOCK))?;
+        #[cfg(not(any(target_os = "espidf", target_os = "vita", target_os = "nto")))]
+        syscall!(fcntl(fds[0], libc::F_SETFD, libc::FD_CLOEXEC))?;
+        syscall!(fcntl(fds[1], libc::F_SETFL, libc::O_NONBLOCK))?;
+        #[cfg(not(any(target_os = "espidf", target_os = "vita", target_os = "nto")))]
+        syscall!(fcntl(fds[1], libc::F_SETFD, libc::FD_CLOEXEC))?;
+    }
+
+    Ok(pair)
+}
+
+#[cfg(test)]
+mod tests {
+    use std::os::unix::net::SocketAddr;
+    use std::path::Path;
+    use std::str;
+
+    use super::{path_offset, unix_addr};
+
+    #[test]
+    fn pathname_address() {
+        const PATH: &str = "./foo/bar.txt";
+        const PATH_LEN: usize = 13;
+
+        // Pathname addresses do have a null terminator, so `socklen` is
+        // expected to be `PATH_LEN` + `offset` + 1.
+        let address = SocketAddr::from_pathname(Path::new(PATH)).unwrap();
+        let (sockaddr, actual) = unix_addr(&address);
+        let offset = path_offset(&sockaddr);
+        let expected = PATH_LEN + offset + 1;
+        assert_eq!(expected as libc::socklen_t, actual)
+    }
+
+    #[test]
+    #[cfg(any(target_os = "android", target_os = "linux"))]
+    fn abstract_address() {
+        #[cfg(target_os = "android")]
+        use std::os::android::net::SocketAddrExt;
+        #[cfg(target_os = "linux")]
+        use std::os::linux::net::SocketAddrExt;
+
+        const PATH: &[u8] = &[0, 116, 111, 107, 105, 111];
+        const PATH_LEN: usize = 6;
+
+        // Abstract addresses do not have a null terminator, so `socklen` is
+        // expected to be `PATH_LEN` + `offset`.
+        let address = SocketAddr::from_abstract_name(PATH).unwrap();
+        let (sockaddr, actual) = unix_addr(&address);
+        let offset = path_offset(&sockaddr);
+        let expected = PATH_LEN + offset;
+        assert_eq!(expected as libc::socklen_t, actual)
+    }
+}

vendor/mio/src/sys/unix/uds/stream.rs

@@ -0,0 +1,25 @@
+use std::io;
+use std::os::fd::FromRawFd;
+use std::os::unix::net::{self, SocketAddr};
+
+use crate::sys::unix::net::new_socket;
+use crate::sys::unix::uds::unix_addr;
+
+pub(crate) fn connect_addr(address: &SocketAddr) -> io::Result<net::UnixStream> {
+    let fd = new_socket(libc::AF_UNIX, libc::SOCK_STREAM)?;
+    let socket = unsafe { net::UnixStream::from_raw_fd(fd) };
+
+    let (unix_address, addrlen) = unix_addr(address);
+    let sockaddr = &unix_address as *const libc::sockaddr_un as *const libc::sockaddr;
+    match syscall!(connect(fd, sockaddr, addrlen)) {
+        Ok(_) => {}
+        Err(ref err) if err.raw_os_error() == Some(libc::EINPROGRESS) => {}
+        Err(e) => return Err(e),
+    }
+
+    Ok(socket)
+}
+
+pub(crate) fn pair() -> io::Result<(net::UnixStream, net::UnixStream)> {
+    super::pair(libc::SOCK_STREAM)
+}

vendor/mio/src/sys/unix/waker/eventfd.rs

@@ -0,0 +1,88 @@
+use std::fs::File;
+use std::io::{self, Read, Write};
+#[cfg(not(target_os = "hermit"))]
+use std::os::fd::{AsRawFd, FromRawFd, RawFd};
+// TODO: once <https://github.com/rust-lang/rust/issues/126198> is fixed this
+// can use `std::os::fd` and be merged with the above.
+#[cfg(target_os = "hermit")]
+use std::os::hermit::io::{AsRawFd, FromRawFd, RawFd};
+
+use crate::sys::Selector;
+use crate::{Interest, Token};
+
+/// Waker backed by `eventfd`.
+///
+/// `eventfd` is effectively an 64 bit counter. All writes must be of 8
+/// bytes (64 bits) and are converted (native endian) into an 64 bit
+/// unsigned integer and added to the count. Reads must also be 8 bytes and
+/// reset the count to 0, returning the count.
+#[derive(Debug)]
+pub(crate) struct Waker {
+    fd: File,
+}
+
+impl Waker {
+    #[allow(dead_code)] // Not used by the `poll(2)` implementation.
+    pub(crate) fn new(selector: &Selector, token: Token) -> io::Result<Waker> {
+        let waker = Waker::new_unregistered()?;
+        selector.register(waker.fd.as_raw_fd(), token, Interest::READABLE)?;
+        Ok(waker)
+    }
+
+    pub(crate) fn new_unregistered() -> io::Result<Waker> {
+        #[cfg(not(target_os = "espidf"))]
+        let flags = libc::EFD_CLOEXEC | libc::EFD_NONBLOCK;
+        // ESP-IDF is EFD_NONBLOCK by default and errors if you try to pass this flag.
+        #[cfg(target_os = "espidf")]
+        let flags = 0;
+        let fd = syscall!(eventfd(0, flags))?;
+        let file = unsafe { File::from_raw_fd(fd) };
+        Ok(Waker { fd: file })
+    }
+
+    #[allow(clippy::unused_io_amount)] // Don't care about partial writes.
+    pub(crate) fn wake(&self) -> io::Result<()> {
+        // The epoll emulation on some illumos systems currently requires
+        // the eventfd to be read before an edge-triggered read event is
+        // generated.
+        // See https://www.illumos.org/issues/16700.
+        #[cfg(target_os = "illumos")]
+        self.reset()?;
+
+        let buf: [u8; 8] = 1u64.to_ne_bytes();
+        match (&self.fd).write(&buf) {
+            Ok(_) => Ok(()),
+            Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
+                // Writing only blocks if the counter is going to overflow.
+                // So we'll reset the counter to 0 and wake it again.
+                self.reset()?;
+                self.wake()
+            }
+            Err(err) => Err(err),
+        }
+    }
+
+    #[allow(dead_code)] // Only used by the `poll(2)` implementation.
+    pub(crate) fn ack_and_reset(&self) {
+        let _ = self.reset();
+    }
+
+    /// Reset the eventfd object, only need to call this if `wake` fails.
+    #[allow(clippy::unused_io_amount)] // Don't care about partial reads.
+    fn reset(&self) -> io::Result<()> {
+        let mut buf: [u8; 8] = 0u64.to_ne_bytes();
+        match (&self.fd).read(&mut buf) {
+            Ok(_) => Ok(()),
+            // If the `Waker` hasn't been awoken yet this will return a
+            // `WouldBlock` error which we can safely ignore.
+            Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => Ok(()),
+            Err(err) => Err(err),
+        }
+    }
+}
+
+impl AsRawFd for Waker {
+    fn as_raw_fd(&self) -> RawFd {
+        self.fd.as_raw_fd()
+    }
+}

vendor/mio/src/sys/unix/waker/kqueue.rs

@@ -0,0 +1,28 @@
+use std::io;
+
+use crate::sys::Selector;
+use crate::Token;
+
+/// Waker backed by kqueue user space notifications (`EVFILT_USER`).
+///
+/// The implementation is fairly simple, first the kqueue must be setup to
+/// receive waker events this done by calling `Selector.setup_waker`. Next
+/// we need access to kqueue, thus we need to duplicate the file descriptor.
+/// Now waking is as simple as adding an event to the kqueue.
+#[derive(Debug)]
+pub(crate) struct Waker {
+    selector: Selector,
+    token: Token,
+}
+
+impl Waker {
+    pub(crate) fn new(selector: &Selector, token: Token) -> io::Result<Waker> {
+        let selector = selector.try_clone()?;
+        selector.setup_waker(token)?;
+        Ok(Waker { selector, token })
+    }
+
+    pub(crate) fn wake(&self) -> io::Result<()> {
+        self.selector.wake(self.token)
+    }
+}

vendor/mio/src/sys/unix/waker/pipe.rs

@@ -0,0 +1,82 @@
+use std::fs::File;
+use std::io::{self, Read, Write};
+#[cfg(not(target_os = "hermit"))]
+use std::os::fd::{AsRawFd, FromRawFd, RawFd};
+// TODO: once <https://github.com/rust-lang/rust/issues/126198> is fixed this
+// can use `std::os::fd` and be merged with the above.
+#[cfg(target_os = "hermit")]
+use std::os::hermit::io::{AsRawFd, FromRawFd, RawFd};
+
+use crate::sys::unix::pipe;
+use crate::sys::Selector;
+use crate::{Interest, Token};
+
+/// Waker backed by a unix pipe.
+///
+/// Waker controls both the sending and receiving ends and empties the pipe
+/// if writing to it (waking) fails.
+#[derive(Debug)]
+pub(crate) struct Waker {
+    sender: File,
+    receiver: File,
+}
+
+impl Waker {
+    #[allow(dead_code)] // Not used by the `poll(2)` implementation.
+    pub(crate) fn new(selector: &Selector, token: Token) -> io::Result<Waker> {
+        let waker = Waker::new_unregistered()?;
+        selector.register(waker.receiver.as_raw_fd(), token, Interest::READABLE)?;
+        Ok(waker)
+    }
+
+    pub(crate) fn new_unregistered() -> io::Result<Waker> {
+        let [receiver, sender] = pipe::new_raw()?;
+        let sender = unsafe { File::from_raw_fd(sender) };
+        let receiver = unsafe { File::from_raw_fd(receiver) };
+        Ok(Waker { sender, receiver })
+    }
+
+    pub(crate) fn wake(&self) -> io::Result<()> {
+        // The epoll emulation on some illumos systems currently requires
+        // the pipe buffer to be completely empty for an edge-triggered
+        // wakeup on the pipe read side.
+        // See https://www.illumos.org/issues/13436.
+        #[cfg(target_os = "illumos")]
+        self.empty();
+
+        match (&self.sender).write(&[1]) {
+            Ok(_) => Ok(()),
+            Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
+                // The reading end is full so we'll empty the buffer and try
+                // again.
+                self.empty();
+                self.wake()
+            }
+            Err(ref err) if err.kind() == io::ErrorKind::Interrupted => self.wake(),
+            Err(err) => Err(err),
+        }
+    }
+
+    #[allow(dead_code)] // Only used by the `poll(2)` implementation.
+    pub(crate) fn ack_and_reset(&self) {
+        self.empty();
+    }
+
+    /// Empty the pipe's buffer, only need to call this if `wake` fails.
+    /// This ignores any errors.
+    fn empty(&self) {
+        let mut buf = [0; 4096];
+        loop {
+            match (&self.receiver).read(&mut buf) {
+                Ok(n) if n > 0 => continue,
+                _ => return,
+            }
+        }
+    }
+}
+
+impl AsRawFd for Waker {
+    fn as_raw_fd(&self) -> RawFd {
+        self.receiver.as_raw_fd()
+    }
+}

vendor/mio/src/sys/wasi/mod.rs

@@ -0,0 +1,369 @@
+//! # Notes
+//!
+//! The current implementation is somewhat limited. The `Waker` is not
+//! implemented, as at the time of writing there is no way to support to wake-up
+//! a thread from calling `poll_oneoff`.
+//!
+//! Furthermore the (re/de)register functions also don't work while concurrently
+//! polling as both registering and polling requires a lock on the
+//! `subscriptions`.
+//!
+//! Finally `Selector::try_clone`, required by `Registry::try_clone`, doesn't
+//! work. However this could be implemented by use of an `Arc`.
+//!
+//! In summary, this only (barely) works using a single thread.
+
+use std::cmp::min;
+use std::io;
+#[cfg(all(feature = "net", debug_assertions))]
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+#[cfg(feature = "net")]
+use crate::{Interest, Token};
+
+cfg_net! {
+    pub(crate) mod tcp {
+        use std::io;
+        use std::net::{self, SocketAddr};
+
+        pub(crate) fn accept(listener: &net::TcpListener) -> io::Result<(net::TcpStream, SocketAddr)> {
+            let (stream, addr) = listener.accept()?;
+            stream.set_nonblocking(true)?;
+            Ok((stream, addr))
+        }
+    }
+}
+
+/// Unique id for use as `SelectorId`.
+#[cfg(all(debug_assertions, feature = "net"))]
+static NEXT_ID: AtomicUsize = AtomicUsize::new(1);
+
+pub(crate) struct Selector {
+    #[cfg(all(debug_assertions, feature = "net"))]
+    id: usize,
+    /// Subscriptions (reads events) we're interested in.
+    subscriptions: Arc<Mutex<Vec<wasi::Subscription>>>,
+}
+
+impl Selector {
+    pub(crate) fn new() -> io::Result<Selector> {
+        Ok(Selector {
+            #[cfg(all(debug_assertions, feature = "net"))]
+            id: NEXT_ID.fetch_add(1, Ordering::Relaxed),
+            subscriptions: Arc::new(Mutex::new(Vec::new())),
+        })
+    }
+
+    #[cfg(all(debug_assertions, feature = "net"))]
+    pub(crate) fn id(&self) -> usize {
+        self.id
+    }
+
+    pub(crate) fn select(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<()> {
+        events.clear();
+
+        let mut subscriptions = self.subscriptions.lock().unwrap();
+
+        // If we want to a use a timeout in the `wasi_poll_oneoff()` function
+        // we need another subscription to the list.
+        if let Some(timeout) = timeout {
+            subscriptions.push(timeout_subscription(timeout));
+        }
+
+        // `poll_oneoff` needs the same number of events as subscriptions.
+        let length = subscriptions.len();
+        events.reserve(length);
+
+        debug_assert!(events.capacity() >= length);
+        #[cfg(debug_assertions)]
+        if length == 0 {
+            warn!(
+                "calling mio::Poll::poll with empty subscriptions, this likely not what you want"
+            );
+        }
+
+        let res = unsafe { wasi::poll_oneoff(subscriptions.as_ptr(), events.as_mut_ptr(), length) };
+
+        // Remove the timeout subscription we possibly added above.
+        if timeout.is_some() {
+            let timeout_sub = subscriptions.pop();
+            debug_assert_eq!(
+                timeout_sub.unwrap().u.tag,
+                wasi::EVENTTYPE_CLOCK.raw(),
+                "failed to remove timeout subscription"
+            );
+        }
+
+        drop(subscriptions); // Unlock.
+
+        match res {
+            Ok(n_events) => {
+                // Safety: `poll_oneoff` initialises the `events` for us.
+                unsafe { events.set_len(n_events) };
+
+                // Remove the timeout event.
+                if timeout.is_some() {
+                    if let Some(index) = events.iter().position(is_timeout_event) {
+                        events.swap_remove(index);
+                    }
+                }
+
+                check_errors(&events)
+            }
+            Err(err) => Err(io_err(err)),
+        }
+    }
+
+    pub(crate) fn try_clone(&self) -> io::Result<Selector> {
+        Ok(Selector {
+            #[cfg(all(debug_assertions, feature = "net"))]
+            id: self.id,
+            subscriptions: self.subscriptions.clone(),
+        })
+    }
+
+    cfg_io_source! {
+    pub(crate) fn register(
+        &self,
+        fd: wasi::Fd,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        let mut subscriptions = self.subscriptions.lock().unwrap();
+
+        if interests.is_writable() {
+            let subscription = wasi::Subscription {
+                userdata: token.0 as wasi::Userdata,
+                u: wasi::SubscriptionU {
+                    tag: wasi::EVENTTYPE_FD_WRITE.raw(),
+                    u: wasi::SubscriptionUU {
+                        fd_write: wasi::SubscriptionFdReadwrite {
+                            file_descriptor: fd,
+                        },
+                    },
+                },
+            };
+            subscriptions.push(subscription);
+        }
+
+        if interests.is_readable() {
+            let subscription = wasi::Subscription {
+                userdata: token.0 as wasi::Userdata,
+                u: wasi::SubscriptionU {
+                    tag: wasi::EVENTTYPE_FD_READ.raw(),
+                    u: wasi::SubscriptionUU {
+                        fd_read: wasi::SubscriptionFdReadwrite {
+                            file_descriptor: fd,
+                        },
+                    },
+                },
+            };
+            subscriptions.push(subscription);
+        }
+
+        Ok(())
+    }
+
+    pub(crate) fn reregister(
+        &self,
+        fd: wasi::Fd,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        self.deregister(fd)
+            .and_then(|()| self.register(fd, token, interests))
+    }
+
+    pub(crate) fn deregister(&self, fd: wasi::Fd) -> io::Result<()> {
+        let mut subscriptions = self.subscriptions.lock().unwrap();
+
+        let predicate = |subscription: &wasi::Subscription| {
+            // Safety: `subscription.u.tag` defines the type of the union in
+            // `subscription.u.u`.
+            match subscription.u.tag {
+                t if t == wasi::EVENTTYPE_FD_WRITE.raw() => unsafe {
+                    subscription.u.u.fd_write.file_descriptor == fd
+                },
+                t if t == wasi::EVENTTYPE_FD_READ.raw() => unsafe {
+                    subscription.u.u.fd_read.file_descriptor == fd
+                },
+                _ => false,
+            }
+        };
+
+        let mut ret = Err(io::ErrorKind::NotFound.into());
+
+        while let Some(index) = subscriptions.iter().position(predicate) {
+            subscriptions.swap_remove(index);
+            ret = Ok(())
+        }
+
+        ret
+    }
+    }
+}
+
+/// Token used to a add a timeout subscription, also used in removing it again.
+const TIMEOUT_TOKEN: wasi::Userdata = wasi::Userdata::MAX;
+
+/// Returns a `wasi::Subscription` for `timeout`.
+fn timeout_subscription(timeout: Duration) -> wasi::Subscription {
+    wasi::Subscription {
+        userdata: TIMEOUT_TOKEN,
+        u: wasi::SubscriptionU {
+            tag: wasi::EVENTTYPE_CLOCK.raw(),
+            u: wasi::SubscriptionUU {
+                clock: wasi::SubscriptionClock {
+                    id: wasi::CLOCKID_MONOTONIC,
+                    // Timestamp is in nanoseconds.
+                    timeout: min(wasi::Timestamp::MAX as u128, timeout.as_nanos())
+                        as wasi::Timestamp,
+                    // Give the implementation another millisecond to coalesce
+                    // events.
+                    precision: Duration::from_millis(1).as_nanos() as wasi::Timestamp,
+                    // Zero means the `timeout` is considered relative to the
+                    // current time.
+                    flags: 0,
+                },
+            },
+        },
+    }
+}
+
+fn is_timeout_event(event: &wasi::Event) -> bool {
+    event.type_ == wasi::EVENTTYPE_CLOCK && event.userdata == TIMEOUT_TOKEN
+}
+
+/// Check all events for possible errors, it returns the first error found.
+fn check_errors(events: &[Event]) -> io::Result<()> {
+    for event in events {
+        if event.error != wasi::ERRNO_SUCCESS {
+            return Err(io_err(event.error));
+        }
+    }
+    Ok(())
+}
+
+/// Convert `wasi::Errno` into an `io::Error`.
+fn io_err(errno: wasi::Errno) -> io::Error {
+    // TODO: check if this is valid.
+    io::Error::from_raw_os_error(errno.raw() as i32)
+}
+
+pub(crate) type Events = Vec<Event>;
+
+pub(crate) type Event = wasi::Event;
+
+pub(crate) mod event {
+    use std::fmt;
+
+    use crate::sys::Event;
+    use crate::Token;
+
+    pub(crate) fn token(event: &Event) -> Token {
+        Token(event.userdata as usize)
+    }
+
+    pub(crate) fn is_readable(event: &Event) -> bool {
+        event.type_ == wasi::EVENTTYPE_FD_READ
+    }
+
+    pub(crate) fn is_writable(event: &Event) -> bool {
+        event.type_ == wasi::EVENTTYPE_FD_WRITE
+    }
+
+    pub(crate) fn is_error(_: &Event) -> bool {
+        // Not supported? It could be that `wasi::Event.error` could be used for
+        // this, but the docs say `error that occurred while processing the
+        // subscription request`, so it's checked in `Select::select` already.
+        false
+    }
+
+    pub(crate) fn is_read_closed(event: &Event) -> bool {
+        event.type_ == wasi::EVENTTYPE_FD_READ
+            // Safety: checked the type of the union above.
+            && (event.fd_readwrite.flags & wasi::EVENTRWFLAGS_FD_READWRITE_HANGUP) != 0
+    }
+
+    pub(crate) fn is_write_closed(event: &Event) -> bool {
+        event.type_ == wasi::EVENTTYPE_FD_WRITE
+            // Safety: checked the type of the union above.
+            && (event.fd_readwrite.flags & wasi::EVENTRWFLAGS_FD_READWRITE_HANGUP) != 0
+    }
+
+    pub(crate) fn is_priority(_: &Event) -> bool {
+        // Not supported.
+        false
+    }
+
+    pub(crate) fn is_aio(_: &Event) -> bool {
+        // Not supported.
+        false
+    }
+
+    pub(crate) fn is_lio(_: &Event) -> bool {
+        // Not supported.
+        false
+    }
+
+    pub(crate) fn debug_details(f: &mut fmt::Formatter<'_>, event: &Event) -> fmt::Result {
+        debug_detail!(
+            TypeDetails(wasi::Eventtype),
+            PartialEq::eq,
+            wasi::EVENTTYPE_CLOCK,
+            wasi::EVENTTYPE_FD_READ,
+            wasi::EVENTTYPE_FD_WRITE,
+        );
+
+        #[allow(clippy::trivially_copy_pass_by_ref)]
+        fn check_flag(got: &wasi::Eventrwflags, want: &wasi::Eventrwflags) -> bool {
+            (got & want) != 0
+        }
+        debug_detail!(
+            EventrwflagsDetails(wasi::Eventrwflags),
+            check_flag,
+            wasi::EVENTRWFLAGS_FD_READWRITE_HANGUP,
+        );
+
+        struct EventFdReadwriteDetails(wasi::EventFdReadwrite);
+
+        impl fmt::Debug for EventFdReadwriteDetails {
+            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+                f.debug_struct("EventFdReadwrite")
+                    .field("nbytes", &self.0.nbytes)
+                    .field("flags", &EventrwflagsDetails(self.0.flags))
+                    .finish()
+            }
+        }
+
+        f.debug_struct("Event")
+            .field("userdata", &event.userdata)
+            .field("error", &event.error)
+            .field("type", &TypeDetails(event.type_))
+            .field("fd_readwrite", &EventFdReadwriteDetails(event.fd_readwrite))
+            .finish()
+    }
+}
+
+cfg_os_poll! {
+    cfg_io_source! {
+        pub(crate) struct IoSourceState;
+
+        impl IoSourceState {
+            pub(crate) fn new() -> IoSourceState {
+                IoSourceState
+            }
+
+            pub(crate) fn do_io<T, F, R>(&self, f: F, io: &T) -> io::Result<R>
+            where
+                F: FnOnce(&T) -> io::Result<R>,
+            {
+                // We don't hold state, so we can just call the function and
+                // return.
+                f(io)
+            }
+        }
+    }
+}

vendor/mio/src/sys/windows/afd.rs

@@ -0,0 +1,243 @@
+use std::ffi::c_void;
+use std::fmt;
+use std::fs::File;
+use std::io;
+use std::mem::size_of;
+use std::os::windows::io::AsRawHandle;
+
+use windows_sys::Wdk::Storage::FileSystem::NtCancelIoFileEx;
+use windows_sys::Wdk::System::IO::NtDeviceIoControlFile;
+use windows_sys::Win32::Foundation::{
+    RtlNtStatusToDosError, HANDLE, NTSTATUS, STATUS_NOT_FOUND, STATUS_PENDING, STATUS_SUCCESS,
+};
+use windows_sys::Win32::System::IO::{IO_STATUS_BLOCK, IO_STATUS_BLOCK_0};
+
+const IOCTL_AFD_POLL: u32 = 0x00012024;
+
+/// Winsock2 AFD driver instance.
+///
+/// All operations are unsafe due to IO_STATUS_BLOCK parameter are being used by Afd driver during STATUS_PENDING before I/O Completion Port returns its result.
+#[derive(Debug)]
+pub struct Afd {
+    fd: File,
+}
+
+#[repr(C)]
+#[derive(Debug)]
+pub struct AfdPollHandleInfo {
+    pub handle: HANDLE,
+    pub events: u32,
+    pub status: NTSTATUS,
+}
+
+unsafe impl Send for AfdPollHandleInfo {}
+
+#[repr(C)]
+pub struct AfdPollInfo {
+    pub timeout: i64,
+    // Can have only value 1.
+    pub number_of_handles: u32,
+    pub exclusive: u32,
+    pub handles: [AfdPollHandleInfo; 1],
+}
+
+impl fmt::Debug for AfdPollInfo {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("AfdPollInfo").finish()
+    }
+}
+
+impl Afd {
+    /// Poll `Afd` instance with `AfdPollInfo`.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe due to memory of `IO_STATUS_BLOCK` still being used by `Afd` instance while `Ok(false)` (`STATUS_PENDING`).
+    /// `iosb` needs to be untouched after the call while operation is in effective at ALL TIME except for `cancel` method.
+    /// So be careful not to `poll` twice while polling.
+    /// User should deallocate there overlapped value when error to prevent memory leak.
+    pub unsafe fn poll(
+        &self,
+        info: &mut AfdPollInfo,
+        iosb: *mut IO_STATUS_BLOCK,
+        overlapped: *mut c_void,
+    ) -> io::Result<bool> {
+        let info_ptr = info as *mut _ as *mut c_void;
+        (*iosb).Anonymous.Status = STATUS_PENDING;
+        let status = NtDeviceIoControlFile(
+            self.fd.as_raw_handle() as HANDLE,
+            std::ptr::null_mut(),
+            None,
+            overlapped,
+            iosb,
+            IOCTL_AFD_POLL,
+            info_ptr,
+            size_of::<AfdPollInfo>() as u32,
+            info_ptr,
+            size_of::<AfdPollInfo>() as u32,
+        );
+        match status {
+            STATUS_SUCCESS => Ok(true),
+            STATUS_PENDING => Ok(false),
+            _ => Err(io::Error::from_raw_os_error(
+                RtlNtStatusToDosError(status) as i32
+            )),
+        }
+    }
+
+    /// Cancel previous polled request of `Afd`.
+    ///
+    /// iosb needs to be used by `poll` first for valid `cancel`.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe due to memory of `IO_STATUS_BLOCK` still being used by `Afd` instance while `Ok(false)` (`STATUS_PENDING`).
+    /// Use it only with request is still being polled so that you have valid `IO_STATUS_BLOCK` to use.
+    /// User should NOT deallocate there overlapped value after the `cancel` to prevent double free.
+    pub unsafe fn cancel(&self, iosb: *mut IO_STATUS_BLOCK) -> io::Result<()> {
+        if (*iosb).Anonymous.Status != STATUS_PENDING {
+            return Ok(());
+        }
+
+        let mut cancel_iosb = IO_STATUS_BLOCK {
+            Anonymous: IO_STATUS_BLOCK_0 { Status: 0 },
+            Information: 0,
+        };
+        let status = NtCancelIoFileEx(self.fd.as_raw_handle() as HANDLE, iosb, &mut cancel_iosb);
+        if status == STATUS_SUCCESS || status == STATUS_NOT_FOUND {
+            return Ok(());
+        }
+        Err(io::Error::from_raw_os_error(
+            RtlNtStatusToDosError(status) as i32
+        ))
+    }
+}
+
+cfg_io_source! {
+    use std::mem::zeroed;
+    use std::os::windows::io::{FromRawHandle, RawHandle};
+    use std::ptr::null_mut;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+
+    use windows_sys::Wdk::Foundation::OBJECT_ATTRIBUTES;
+    use windows_sys::Wdk::Storage::FileSystem::{NtCreateFile, FILE_OPEN};
+    use windows_sys::Win32::Foundation::{INVALID_HANDLE_VALUE, UNICODE_STRING};
+    use windows_sys::Win32::Storage::FileSystem::{
+        SetFileCompletionNotificationModes, FILE_SHARE_READ, FILE_SHARE_WRITE, SYNCHRONIZE,
+    };
+    use windows_sys::Win32::System::WindowsProgramming::FILE_SKIP_SET_EVENT_ON_HANDLE;
+
+    use super::iocp::CompletionPort;
+
+    const AFD_HELPER_ATTRIBUTES: OBJECT_ATTRIBUTES = OBJECT_ATTRIBUTES {
+        Length: size_of::<OBJECT_ATTRIBUTES>() as u32,
+        RootDirectory: null_mut(),
+        ObjectName: &AFD_OBJ_NAME as *const _ as *mut _,
+        Attributes: 0,
+        SecurityDescriptor: null_mut(),
+        SecurityQualityOfService: null_mut(),
+    };
+
+    const AFD_OBJ_NAME: UNICODE_STRING = UNICODE_STRING {
+        Length: (AFD_HELPER_NAME.len() * size_of::<u16>()) as u16,
+        MaximumLength: (AFD_HELPER_NAME.len() * size_of::<u16>()) as u16,
+        Buffer: AFD_HELPER_NAME.as_ptr() as *mut _,
+    };
+
+    const AFD_HELPER_NAME: &[u16] = &[
+        '\\' as _,
+        'D' as _,
+        'e' as _,
+        'v' as _,
+        'i' as _,
+        'c' as _,
+        'e' as _,
+        '\\' as _,
+        'A' as _,
+        'f' as _,
+        'd' as _,
+        '\\' as _,
+        'M' as _,
+        'i' as _,
+        'o' as _
+    ];
+
+    static NEXT_TOKEN: AtomicUsize = AtomicUsize::new(0);
+
+    impl AfdPollInfo {
+        pub fn zeroed() -> AfdPollInfo {
+            unsafe { zeroed() }
+        }
+    }
+
+    impl Afd {
+        /// Create new Afd instance.
+        pub(crate) fn new(cp: &CompletionPort) -> io::Result<Afd> {
+            let mut afd_helper_handle: HANDLE = INVALID_HANDLE_VALUE;
+            let mut iosb = IO_STATUS_BLOCK {
+                Anonymous: IO_STATUS_BLOCK_0 { Status: 0 },
+                Information: 0,
+            };
+
+            unsafe {
+                let status = NtCreateFile(
+                    &mut afd_helper_handle as *mut _,
+                    SYNCHRONIZE,
+                    &AFD_HELPER_ATTRIBUTES as *const _ as *mut _,
+                    &mut iosb,
+                    null_mut(),
+                    0,
+                    FILE_SHARE_READ | FILE_SHARE_WRITE,
+                    FILE_OPEN,
+                    0,
+                    null_mut(),
+                    0,
+                );
+                if status != STATUS_SUCCESS {
+                    let raw_err = io::Error::from_raw_os_error(
+                        RtlNtStatusToDosError(status) as i32
+                    );
+                    let msg = format!("Failed to open \\Device\\Afd\\Mio: {}", raw_err);
+                    return Err(io::Error::new(raw_err.kind(), msg));
+                }
+                let fd = File::from_raw_handle(afd_helper_handle as RawHandle);
+                // Increment by 2 to reserve space for other types of handles.
+                // Non-AFD types (currently only NamedPipe), use odd numbered
+                // tokens. This allows the selector to differentiate between them
+                // and dispatch events accordingly.
+                let token = NEXT_TOKEN.fetch_add(2, Ordering::Relaxed) + 2;
+                let afd = Afd { fd };
+                cp.add_handle(token, &afd.fd)?;
+                match SetFileCompletionNotificationModes(
+                    afd_helper_handle,
+                    FILE_SKIP_SET_EVENT_ON_HANDLE as u8 // This is just 2, so fits in u8
+                ) {
+                    0 => Err(io::Error::last_os_error()),
+                    _ => Ok(afd),
+                }
+            }
+        }
+    }
+}
+
+pub const POLL_RECEIVE: u32 = 0b0_0000_0001;
+pub const POLL_RECEIVE_EXPEDITED: u32 = 0b0_0000_0010;
+pub const POLL_SEND: u32 = 0b0_0000_0100;
+pub const POLL_DISCONNECT: u32 = 0b0_0000_1000;
+pub const POLL_ABORT: u32 = 0b0_0001_0000;
+pub const POLL_LOCAL_CLOSE: u32 = 0b0_0010_0000;
+// Not used as it indicated in each event where a connection is connected, not
+// just the first time a connection is established.
+// Also see https://github.com/piscisaureus/wepoll/commit/8b7b340610f88af3d83f40fb728e7b850b090ece.
+pub const POLL_CONNECT: u32 = 0b0_0100_0000;
+pub const POLL_ACCEPT: u32 = 0b0_1000_0000;
+pub const POLL_CONNECT_FAIL: u32 = 0b1_0000_0000;
+
+pub const KNOWN_EVENTS: u32 = POLL_RECEIVE
+    | POLL_RECEIVE_EXPEDITED
+    | POLL_SEND
+    | POLL_DISCONNECT
+    | POLL_ABORT
+    | POLL_LOCAL_CLOSE
+    | POLL_ACCEPT
+    | POLL_CONNECT_FAIL;

vendor/mio/src/sys/windows/event.rs

@@ -0,0 +1,169 @@
+use std::fmt;
+
+use super::afd;
+use super::iocp::CompletionStatus;
+use crate::Token;
+
+#[derive(Clone)]
+pub struct Event {
+    pub flags: u32,
+    pub data: u64,
+}
+
+pub fn token(event: &Event) -> Token {
+    Token(event.data as usize)
+}
+
+impl Event {
+    pub(super) fn new(token: Token) -> Event {
+        Event {
+            flags: 0,
+            data: usize::from(token) as u64,
+        }
+    }
+
+    pub(super) fn set_readable(&mut self) {
+        self.flags |= afd::POLL_RECEIVE
+    }
+
+    #[cfg(feature = "os-ext")]
+    pub(super) fn set_writable(&mut self) {
+        self.flags |= afd::POLL_SEND;
+    }
+
+    pub(super) fn from_completion_status(status: &CompletionStatus) -> Event {
+        Event {
+            flags: status.bytes_transferred(),
+            data: status.token() as u64,
+        }
+    }
+
+    pub(super) fn to_completion_status(&self) -> CompletionStatus {
+        CompletionStatus::new(self.flags, self.data as usize, std::ptr::null_mut())
+    }
+
+    #[cfg(feature = "os-ext")]
+    pub(super) fn to_completion_status_with_overlapped(
+        &self,
+        overlapped: *mut super::Overlapped,
+    ) -> CompletionStatus {
+        CompletionStatus::new(self.flags, self.data as usize, overlapped)
+    }
+}
+
+pub(crate) const READABLE_FLAGS: u32 = afd::POLL_RECEIVE
+    | afd::POLL_DISCONNECT
+    | afd::POLL_ACCEPT
+    | afd::POLL_ABORT
+    | afd::POLL_CONNECT_FAIL;
+pub(crate) const WRITABLE_FLAGS: u32 = afd::POLL_SEND | afd::POLL_ABORT | afd::POLL_CONNECT_FAIL;
+pub(crate) const ERROR_FLAGS: u32 = afd::POLL_CONNECT_FAIL;
+pub(crate) const READ_CLOSED_FLAGS: u32 =
+    afd::POLL_DISCONNECT | afd::POLL_ABORT | afd::POLL_CONNECT_FAIL;
+pub(crate) const WRITE_CLOSED_FLAGS: u32 = afd::POLL_ABORT | afd::POLL_CONNECT_FAIL;
+
+pub fn is_readable(event: &Event) -> bool {
+    event.flags & READABLE_FLAGS != 0
+}
+
+pub fn is_writable(event: &Event) -> bool {
+    event.flags & WRITABLE_FLAGS != 0
+}
+
+pub fn is_error(event: &Event) -> bool {
+    event.flags & ERROR_FLAGS != 0
+}
+
+pub fn is_read_closed(event: &Event) -> bool {
+    event.flags & READ_CLOSED_FLAGS != 0
+}
+
+pub fn is_write_closed(event: &Event) -> bool {
+    event.flags & WRITE_CLOSED_FLAGS != 0
+}
+
+pub fn is_priority(event: &Event) -> bool {
+    event.flags & afd::POLL_RECEIVE_EXPEDITED != 0
+}
+
+pub fn is_aio(_: &Event) -> bool {
+    // Not supported.
+    false
+}
+
+pub fn is_lio(_: &Event) -> bool {
+    // Not supported.
+    false
+}
+
+pub fn debug_details(f: &mut fmt::Formatter<'_>, event: &Event) -> fmt::Result {
+    #[allow(clippy::trivially_copy_pass_by_ref)]
+    fn check_flags(got: &u32, want: &u32) -> bool {
+        (got & want) != 0
+    }
+    debug_detail!(
+        FlagsDetails(u32),
+        check_flags,
+        afd::POLL_RECEIVE,
+        afd::POLL_RECEIVE_EXPEDITED,
+        afd::POLL_SEND,
+        afd::POLL_DISCONNECT,
+        afd::POLL_ABORT,
+        afd::POLL_LOCAL_CLOSE,
+        afd::POLL_CONNECT,
+        afd::POLL_ACCEPT,
+        afd::POLL_CONNECT_FAIL,
+    );
+
+    f.debug_struct("event")
+        .field("flags", &FlagsDetails(event.flags))
+        .field("data", &event.data)
+        .finish()
+}
+
+pub struct Events {
+    /// Raw I/O event completions are filled in here by the call to `get_many`
+    /// on the completion port above. These are then processed to run callbacks
+    /// which figure out what to do after the event is done.
+    pub statuses: Box<[CompletionStatus]>,
+
+    /// Literal events returned by `get` to the upwards `EventLoop`. This file
+    /// doesn't really modify this (except for the waker), instead almost all
+    /// events are filled in by the `ReadinessQueue` from the `poll` module.
+    pub events: Vec<Event>,
+}
+
+impl Events {
+    pub fn with_capacity(cap: usize) -> Events {
+        // Note that it's possible for the output `events` to grow beyond the
+        // capacity as it can also include deferred events, but that's certainly
+        // not the end of the world!
+        Events {
+            statuses: vec![CompletionStatus::zero(); cap].into_boxed_slice(),
+            events: Vec::with_capacity(cap),
+        }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.events.is_empty()
+    }
+
+    pub fn capacity(&self) -> usize {
+        self.events.capacity()
+    }
+
+    pub fn len(&self) -> usize {
+        self.events.len()
+    }
+
+    pub fn get(&self, idx: usize) -> Option<&Event> {
+        self.events.get(idx)
+    }
+
+    pub fn clear(&mut self) {
+        self.events.clear();
+        for status in self.statuses.iter_mut() {
+            *status = CompletionStatus::zero();
+        }
+    }
+}

vendor/mio/src/sys/windows/handle.rs

@@ -0,0 +1,30 @@
+use std::os::windows::io::RawHandle;
+use windows_sys::Win32::Foundation::{CloseHandle, HANDLE};
+
+/// Wrapper around a Windows HANDLE so that we close it upon drop in all scenarios
+#[derive(Debug)]
+pub struct Handle(HANDLE);
+
+impl Handle {
+    #[inline]
+    pub fn new(handle: HANDLE) -> Self {
+        Self(handle)
+    }
+
+    pub fn raw(&self) -> HANDLE {
+        self.0
+    }
+
+    pub fn into_raw(self) -> RawHandle {
+        let ret = self.0;
+        // This is super important so that drop is not called!
+        std::mem::forget(self);
+        ret as RawHandle
+    }
+}
+
+impl Drop for Handle {
+    fn drop(&mut self) {
+        unsafe { CloseHandle(self.0) };
+    }
+}

vendor/mio/src/sys/windows/io_status_block.rs

@@ -0,0 +1,40 @@
+use std::fmt;
+use std::ops::{Deref, DerefMut};
+
+use windows_sys::Win32::System::IO::IO_STATUS_BLOCK;
+
+pub struct IoStatusBlock(IO_STATUS_BLOCK);
+
+cfg_io_source! {
+    use windows_sys::Win32::System::IO::IO_STATUS_BLOCK_0;
+
+    impl IoStatusBlock {
+        pub fn zeroed() -> Self {
+            Self(IO_STATUS_BLOCK {
+                Anonymous: IO_STATUS_BLOCK_0 { Status: 0 },
+                Information: 0,
+            })
+        }
+    }
+}
+
+unsafe impl Send for IoStatusBlock {}
+
+impl Deref for IoStatusBlock {
+    type Target = IO_STATUS_BLOCK;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for IoStatusBlock {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl fmt::Debug for IoStatusBlock {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("IoStatusBlock").finish()
+    }
+}

vendor/mio/src/sys/windows/iocp.rs

@@ -0,0 +1,282 @@
+//! Bindings to IOCP, I/O Completion Ports
+
+use super::{Handle, Overlapped};
+use std::cmp;
+use std::fmt;
+use std::io;
+use std::mem;
+use std::os::windows::io::*;
+use std::ptr::null_mut;
+use std::time::Duration;
+
+use windows_sys::Win32::Foundation::{HANDLE, INVALID_HANDLE_VALUE};
+use windows_sys::Win32::System::IO::{
+    CreateIoCompletionPort, GetQueuedCompletionStatusEx, PostQueuedCompletionStatus, OVERLAPPED,
+    OVERLAPPED_ENTRY,
+};
+
+/// A handle to an Windows I/O Completion Port.
+#[derive(Debug)]
+pub(crate) struct CompletionPort {
+    handle: Handle,
+}
+
+// SAFETY: `Handles`s are, in general, not thread-safe. However, we only used `Handle`s for
+// resources that are thread-safe in `CompletionPort`.
+unsafe impl Send for CompletionPort {}
+
+// SAFETY: `Handles`s are, in general, not thread-safe. However, we only used `Handle`s for
+// resources that are thread-safe in `CompletionPort`.
+unsafe impl Sync for CompletionPort {}
+
+/// A status message received from an I/O completion port.
+///
+/// These statuses can be created via the `new` or `empty` constructors and then
+/// provided to a completion port, or they are read out of a completion port.
+/// The fields of each status are read through its accessor methods.
+#[derive(Clone, Copy)]
+#[repr(transparent)]
+pub struct CompletionStatus(OVERLAPPED_ENTRY);
+
+impl fmt::Debug for CompletionStatus {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "CompletionStatus(OVERLAPPED_ENTRY)")
+    }
+}
+
+unsafe impl Send for CompletionStatus {}
+unsafe impl Sync for CompletionStatus {}
+
+impl CompletionPort {
+    /// Creates a new I/O completion port with the specified concurrency value.
+    ///
+    /// The number of threads given corresponds to the level of concurrency
+    /// allowed for threads associated with this port. Consult the Windows
+    /// documentation for more information about this value.
+    pub fn new(threads: u32) -> io::Result<CompletionPort> {
+        let ret = unsafe { CreateIoCompletionPort(INVALID_HANDLE_VALUE, null_mut(), 0, threads) };
+        if ret.is_null() {
+            Err(io::Error::last_os_error())
+        } else {
+            Ok(CompletionPort {
+                handle: Handle::new(ret),
+            })
+        }
+    }
+
+    /// Associates a new `HANDLE` to this I/O completion port.
+    ///
+    /// This function will associate the given handle to this port with the
+    /// given `token` to be returned in status messages whenever it receives a
+    /// notification.
+    ///
+    /// Any object which is convertible to a `HANDLE` via the `AsRawHandle`
+    /// trait can be provided to this function, such as `std::fs::File` and
+    /// friends.
+    #[cfg(any(feature = "net", feature = "os-ext"))]
+    pub fn add_handle<T: AsRawHandle + ?Sized>(&self, token: usize, t: &T) -> io::Result<()> {
+        let ret = unsafe {
+            CreateIoCompletionPort(t.as_raw_handle() as HANDLE, self.handle.raw(), token, 0)
+        };
+        if ret.is_null() {
+            Err(io::Error::last_os_error())
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Dequeues a number of completion statuses from this I/O completion port.
+    ///
+    /// This function is the same as `get` except that it may return more than
+    /// one status. A buffer of "zero" statuses is provided (the contents are
+    /// not read) and then on success this function will return a sub-slice of
+    /// statuses which represent those which were dequeued from this port. This
+    /// function does not wait to fill up the entire list of statuses provided.
+    ///
+    /// Like with `get`, a timeout may be specified for this operation.
+    pub fn get_many<'a>(
+        &self,
+        list: &'a mut [CompletionStatus],
+        timeout: Option<Duration>,
+    ) -> io::Result<&'a mut [CompletionStatus]> {
+        debug_assert_eq!(
+            mem::size_of::<CompletionStatus>(),
+            mem::size_of::<OVERLAPPED_ENTRY>()
+        );
+        let mut removed = 0;
+        let timeout = duration_millis(timeout);
+        let len = cmp::min(list.len(), u32::MAX as usize) as u32;
+        let ret = unsafe {
+            GetQueuedCompletionStatusEx(
+                self.handle.raw(),
+                list.as_ptr() as *mut _,
+                len,
+                &mut removed,
+                timeout,
+                0,
+            )
+        };
+
+        if ret == 0 {
+            Err(io::Error::last_os_error())
+        } else {
+            Ok(&mut list[..removed as usize])
+        }
+    }
+
+    /// Posts a new completion status onto this I/O completion port.
+    ///
+    /// This function will post the given status, with custom parameters, to the
+    /// port. Threads blocked in `get` or `get_many` will eventually receive
+    /// this status.
+    pub fn post(&self, status: CompletionStatus) -> io::Result<()> {
+        let ret = unsafe {
+            PostQueuedCompletionStatus(
+                self.handle.raw(),
+                status.0.dwNumberOfBytesTransferred,
+                status.0.lpCompletionKey,
+                status.0.lpOverlapped,
+            )
+        };
+
+        if ret == 0 {
+            Err(io::Error::last_os_error())
+        } else {
+            Ok(())
+        }
+    }
+}
+
+impl AsRawHandle for CompletionPort {
+    fn as_raw_handle(&self) -> RawHandle {
+        self.handle.raw() as RawHandle
+    }
+}
+
+impl FromRawHandle for CompletionPort {
+    unsafe fn from_raw_handle(handle: RawHandle) -> CompletionPort {
+        CompletionPort {
+            handle: Handle::new(handle as HANDLE),
+        }
+    }
+}
+
+impl IntoRawHandle for CompletionPort {
+    fn into_raw_handle(self) -> RawHandle {
+        self.handle.into_raw()
+    }
+}
+
+impl CompletionStatus {
+    /// Creates a new completion status with the provided parameters.
+    ///
+    /// This function is useful when creating a status to send to a port with
+    /// the `post` method. The parameters are opaquely passed through and not
+    /// interpreted by the system at all.
+    pub(crate) fn new(bytes: u32, token: usize, overlapped: *mut Overlapped) -> Self {
+        CompletionStatus(OVERLAPPED_ENTRY {
+            dwNumberOfBytesTransferred: bytes,
+            lpCompletionKey: token,
+            lpOverlapped: overlapped as *mut _,
+            Internal: 0,
+        })
+    }
+
+    /// Creates a new borrowed completion status from the borrowed
+    /// `OVERLAPPED_ENTRY` argument provided.
+    ///
+    /// This method will wrap the `OVERLAPPED_ENTRY` in a `CompletionStatus`,
+    /// returning the wrapped structure.
+    #[cfg(feature = "os-ext")]
+    pub fn from_entry(entry: &OVERLAPPED_ENTRY) -> &Self {
+        // Safety: CompletionStatus is repr(transparent) w/ OVERLAPPED_ENTRY, so
+        // a reference to one is guaranteed to be layout compatible with the
+        // reference to another.
+        unsafe { &*(entry as *const _ as *const _) }
+    }
+
+    /// Creates a new "zero" completion status.
+    ///
+    /// This function is useful when creating a stack buffer or vector of
+    /// completion statuses to be passed to the `get_many` function.
+    pub fn zero() -> Self {
+        Self::new(0, 0, null_mut())
+    }
+
+    /// Returns the number of bytes that were transferred for the I/O operation
+    /// associated with this completion status.
+    pub fn bytes_transferred(&self) -> u32 {
+        self.0.dwNumberOfBytesTransferred
+    }
+
+    /// Returns the completion key value associated with the file handle whose
+    /// I/O operation has completed.
+    ///
+    /// A completion key is a per-handle key that is specified when it is added
+    /// to an I/O completion port via `add_handle` or `add_socket`.
+    pub fn token(&self) -> usize {
+        self.0.lpCompletionKey as usize
+    }
+
+    /// Returns a pointer to the `Overlapped` structure that was specified when
+    /// the I/O operation was started.
+    pub fn overlapped(&self) -> *mut OVERLAPPED {
+        self.0.lpOverlapped
+    }
+
+    /// Returns a pointer to the internal `OVERLAPPED_ENTRY` object.
+    pub fn entry(&self) -> &OVERLAPPED_ENTRY {
+        &self.0
+    }
+}
+
+#[inline]
+fn duration_millis(dur: Option<Duration>) -> u32 {
+    if let Some(dur) = dur {
+        // `Duration::as_millis` truncates, so round up. This avoids
+        // turning sub-millisecond timeouts into a zero timeout, unless
+        // the caller explicitly requests that by specifying a zero
+        // timeout.
+        let dur_ms = dur
+            .checked_add(Duration::from_nanos(999_999))
+            .unwrap_or(dur)
+            .as_millis();
+        cmp::min(dur_ms, u32::MAX as u128) as u32
+    } else {
+        u32::MAX
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{CompletionPort, CompletionStatus};
+
+    #[test]
+    fn is_send_sync() {
+        fn is_send_sync<T: Send + Sync>() {}
+        is_send_sync::<CompletionPort>();
+    }
+
+    #[test]
+    fn get_many() {
+        let c = CompletionPort::new(1).unwrap();
+
+        c.post(CompletionStatus::new(1, 2, 3 as *mut _)).unwrap();
+        c.post(CompletionStatus::new(4, 5, 6 as *mut _)).unwrap();
+
+        let mut s = vec![CompletionStatus::zero(); 4];
+        {
+            let s = c.get_many(&mut s, None).unwrap();
+            assert_eq!(s.len(), 2);
+            assert_eq!(s[0].bytes_transferred(), 1);
+            assert_eq!(s[0].token(), 2);
+            assert_eq!(s[0].overlapped(), 3 as *mut _);
+            assert_eq!(s[1].bytes_transferred(), 4);
+            assert_eq!(s[1].token(), 5);
+            assert_eq!(s[1].overlapped(), 6 as *mut _);
+        }
+        assert_eq!(s[2].bytes_transferred(), 0);
+        assert_eq!(s[2].token(), 0);
+        assert_eq!(s[2].overlapped(), 0 as *mut _);
+    }
+}

vendor/mio/src/sys/windows/mod.rs

@@ -0,0 +1,154 @@
+mod afd;
+
+pub mod event;
+pub use event::{Event, Events};
+
+mod handle;
+use handle::Handle;
+
+mod io_status_block;
+mod iocp;
+
+mod overlapped;
+use overlapped::Overlapped;
+
+mod selector;
+pub use selector::Selector;
+
+// Macros must be defined before the modules that use them
+cfg_net! {
+    /// Helper macro to execute a system call that returns an `io::Result`.
+    //
+    // Macro must be defined before any modules that uses them.
+    macro_rules! syscall {
+        ($fn: ident ( $($arg: expr),* $(,)* ), $err_test: path, $err_value: expr) => {{
+            let res = unsafe { $fn($($arg, )*) };
+            if $err_test(&res, &$err_value) {
+                Err(io::Error::last_os_error())
+            } else {
+                Ok(res)
+            }
+        }};
+    }
+
+    mod net;
+
+    pub(crate) mod tcp;
+    pub(crate) mod udp;
+
+    pub use selector::{SelectorInner, SockState};
+}
+
+cfg_os_ext! {
+    pub(crate) mod named_pipe;
+}
+
+mod waker;
+pub(crate) use waker::Waker;
+
+cfg_io_source! {
+    use std::io;
+    use std::os::windows::io::RawSocket;
+    use std::pin::Pin;
+    use std::sync::{Arc, Mutex};
+
+    use crate::{Interest, Registry, Token};
+
+    struct InternalState {
+        selector: Arc<SelectorInner>,
+        token: Token,
+        interests: Interest,
+        sock_state: Pin<Arc<Mutex<SockState>>>,
+    }
+
+    impl Drop for InternalState {
+        fn drop(&mut self) {
+            let mut sock_state = self.sock_state.lock().unwrap();
+            sock_state.mark_delete();
+        }
+    }
+
+    pub struct IoSourceState {
+        // This is `None` if the socket has not yet been registered.
+        //
+        // We box the internal state to not increase the size on the stack as the
+        // type might move around a lot.
+        inner: Option<Box<InternalState>>,
+    }
+
+    impl IoSourceState {
+        pub fn new() -> IoSourceState {
+            IoSourceState { inner: None }
+        }
+
+        pub fn do_io<T, F, R>(&self, f: F, io: &T) -> io::Result<R>
+        where
+            F: FnOnce(&T) -> io::Result<R>,
+        {
+            let result = f(io);
+            if let Err(ref e) = result {
+                if e.kind() == io::ErrorKind::WouldBlock {
+                    self.inner.as_ref().map_or(Ok(()), |state| {
+                        state
+                            .selector
+                            .reregister(state.sock_state.clone(), state.token, state.interests)
+                    })?;
+                }
+            }
+            result
+        }
+
+        pub fn register(
+            &mut self,
+            registry: &Registry,
+            token: Token,
+            interests: Interest,
+            socket: RawSocket,
+        ) -> io::Result<()> {
+            if self.inner.is_some() {
+                Err(io::ErrorKind::AlreadyExists.into())
+            } else {
+                registry
+                    .selector()
+                    .register(socket, token, interests)
+                    .map(|state| {
+                        self.inner = Some(Box::new(state));
+                    })
+            }
+        }
+
+        pub fn reregister(
+            &mut self,
+            registry: &Registry,
+            token: Token,
+            interests: Interest,
+        ) -> io::Result<()> {
+            match self.inner.as_mut() {
+                Some(state) => {
+                    registry
+                        .selector()
+                        .reregister(state.sock_state.clone(), token, interests)
+                        .map(|()| {
+                            state.token = token;
+                            state.interests = interests;
+                        })
+                }
+                None => Err(io::ErrorKind::NotFound.into()),
+            }
+        }
+
+        pub fn deregister(&mut self) -> io::Result<()> {
+            match self.inner.as_mut() {
+                Some(state) => {
+                    {
+                        let mut sock_state = state.sock_state.lock().unwrap();
+                        sock_state.mark_delete();
+                    }
+                    self.inner = None;
+                    Ok(())
+                }
+                None => Err(io::ErrorKind::NotFound.into()),
+            }
+        }
+    }
+}

vendor/mio/src/sys/windows/net.rs

@@ -0,0 +1,111 @@
+use std::io;
+use std::mem;
+use std::net::SocketAddr;
+use std::sync::Once;
+
+use windows_sys::Win32::Networking::WinSock::{
+    closesocket, ioctlsocket, socket, AF_INET, AF_INET6, FIONBIO, IN6_ADDR, IN6_ADDR_0,
+    INVALID_SOCKET, IN_ADDR, IN_ADDR_0, SOCKADDR, SOCKADDR_IN, SOCKADDR_IN6, SOCKADDR_IN6_0,
+    SOCKET,
+};
+
+/// Initialise the network stack for Windows.
+fn init() {
+    static INIT: Once = Once::new();
+    INIT.call_once(|| {
+        // Let standard library call `WSAStartup` for us, we can't do it
+        // ourselves because otherwise using any type in `std::net` would panic
+        // when it tries to call `WSAStartup` a second time.
+        drop(std::net::UdpSocket::bind("127.0.0.1:0"));
+    });
+}
+
+/// Create a new non-blocking socket.
+pub(crate) fn new_ip_socket(addr: SocketAddr, socket_type: i32) -> io::Result<SOCKET> {
+    let domain = match addr {
+        SocketAddr::V4(..) => AF_INET,
+        SocketAddr::V6(..) => AF_INET6,
+    };
+
+    new_socket(domain.into(), socket_type)
+}
+
+pub(crate) fn new_socket(domain: u32, socket_type: i32) -> io::Result<SOCKET> {
+    init();
+
+    let socket = syscall!(
+        socket(domain as i32, socket_type, 0),
+        PartialEq::eq,
+        INVALID_SOCKET
+    )?;
+
+    if let Err(err) = syscall!(ioctlsocket(socket, FIONBIO, &mut 1), PartialEq::ne, 0) {
+        let _ = unsafe { closesocket(socket) };
+        return Err(err);
+    }
+
+    Ok(socket as SOCKET)
+}
+
+/// A type with the same memory layout as `SOCKADDR`. Used in converting Rust level
+/// SocketAddr* types into their system representation. The benefit of this specific
+/// type over using `SOCKADDR_STORAGE` is that this type is exactly as large as it
+/// needs to be and not a lot larger. And it can be initialized cleaner from Rust.
+#[repr(C)]
+pub(crate) union SocketAddrCRepr {
+    v4: SOCKADDR_IN,
+    v6: SOCKADDR_IN6,
+}
+
+impl SocketAddrCRepr {
+    pub(crate) fn as_ptr(&self) -> *const SOCKADDR {
+        self as *const _ as *const SOCKADDR
+    }
+}
+
+pub(crate) fn socket_addr(addr: &SocketAddr) -> (SocketAddrCRepr, i32) {
+    match addr {
+        SocketAddr::V4(ref addr) => {
+            // `s_addr` is stored as BE on all machine and the array is in BE order.
+            // So the native endian conversion method is used so that it's never swapped.
+            let sin_addr = unsafe {
+                let mut s_un = mem::zeroed::<IN_ADDR_0>();
+                s_un.S_addr = u32::from_ne_bytes(addr.ip().octets());
+                IN_ADDR { S_un: s_un }
+            };
+
+            let sockaddr_in = SOCKADDR_IN {
+                sin_family: AF_INET as u16, // 1
+                sin_port: addr.port().to_be(),
+                sin_addr,
+                sin_zero: [0; 8],
+            };
+
+            let sockaddr = SocketAddrCRepr { v4: sockaddr_in };
+            (sockaddr, mem::size_of::<SOCKADDR_IN>() as i32)
+        }
+        SocketAddr::V6(ref addr) => {
+            let sin6_addr = unsafe {
+                let mut u = mem::zeroed::<IN6_ADDR_0>();
+                u.Byte = addr.ip().octets();
+                IN6_ADDR { u }
+            };
+            let u = unsafe {
+                let mut u = mem::zeroed::<SOCKADDR_IN6_0>();
+                u.sin6_scope_id = addr.scope_id();
+                u
+            };
+
+            let sockaddr_in6 = SOCKADDR_IN6 {
+                sin6_family: AF_INET6 as u16, // 23
+                sin6_port: addr.port().to_be(),
+                sin6_addr,
+                sin6_flowinfo: addr.flowinfo(),
+                Anonymous: u,
+            };
+
+            let sockaddr = SocketAddrCRepr { v6: sockaddr_in6 };
+            (sockaddr, mem::size_of::<SOCKADDR_IN6>() as i32)
+        }
+    }
+}

vendor/mio/src/sys/windows/overlapped.rs

@@ -0,0 +1,35 @@
+use crate::sys::windows::Event;
+
+use std::cell::UnsafeCell;
+use std::fmt;
+
+use windows_sys::Win32::System::IO::{OVERLAPPED, OVERLAPPED_ENTRY};
+
+#[repr(C)]
+pub(crate) struct Overlapped {
+    inner: UnsafeCell<OVERLAPPED>,
+    pub(crate) callback: fn(&OVERLAPPED_ENTRY, Option<&mut Vec<Event>>),
+}
+
+#[cfg(feature = "os-ext")]
+impl Overlapped {
+    pub(crate) fn new(cb: fn(&OVERLAPPED_ENTRY, Option<&mut Vec<Event>>)) -> Overlapped {
+        Overlapped {
+            inner: UnsafeCell::new(unsafe { std::mem::zeroed() }),
+            callback: cb,
+        }
+    }
+
+    pub(crate) fn as_ptr(&self) -> *const OVERLAPPED {
+        self.inner.get()
+    }
+}
+
+impl fmt::Debug for Overlapped {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Overlapped").finish()
+    }
+}
+
+unsafe impl Send for Overlapped {}
+unsafe impl Sync for Overlapped {}

vendor/mio/src/sys/windows/selector.rs

@@ -0,0 +1,741 @@
+use super::afd::{self, Afd, AfdPollInfo};
+use super::io_status_block::IoStatusBlock;
+use super::Event;
+use crate::sys::Events;
+
+cfg_net! {
+    use crate::sys::event::{
+        ERROR_FLAGS, READABLE_FLAGS, READ_CLOSED_FLAGS, WRITABLE_FLAGS, WRITE_CLOSED_FLAGS,
+    };
+    use crate::Interest;
+}
+
+use super::iocp::{CompletionPort, CompletionStatus};
+use std::collections::VecDeque;
+use std::ffi::c_void;
+use std::io;
+use std::marker::PhantomPinned;
+use std::os::windows::io::RawSocket;
+use std::pin::Pin;
+#[cfg(debug_assertions)]
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+use windows_sys::Win32::Foundation::{
+    ERROR_INVALID_HANDLE, ERROR_IO_PENDING, HANDLE, STATUS_CANCELLED, WAIT_TIMEOUT,
+};
+use windows_sys::Win32::System::IO::OVERLAPPED;
+
+#[derive(Debug)]
+struct AfdGroup {
+    #[cfg_attr(not(feature = "net"), allow(dead_code))]
+    cp: Arc<CompletionPort>,
+    afd_group: Mutex<Vec<Arc<Afd>>>,
+}
+
+impl AfdGroup {
+    pub fn new(cp: Arc<CompletionPort>) -> AfdGroup {
+        AfdGroup {
+            afd_group: Mutex::new(Vec::new()),
+            cp,
+        }
+    }
+
+    pub fn release_unused_afd(&self) {
+        let mut afd_group = self.afd_group.lock().unwrap();
+        afd_group.retain(|g| Arc::strong_count(g) > 1);
+    }
+}
+
+cfg_io_source! {
+    const POLL_GROUP_MAX_GROUP_SIZE: usize = 32;
+
+    impl AfdGroup {
+        pub fn acquire(&self) -> io::Result<Arc<Afd>> {
+            let mut afd_group = self.afd_group.lock().unwrap();
+            if afd_group.len() == 0 {
+                self._alloc_afd_group(&mut afd_group)?;
+            } else {
+                // + 1 reference in Vec
+                if Arc::strong_count(afd_group.last().unwrap()) > POLL_GROUP_MAX_GROUP_SIZE  {
+                    self._alloc_afd_group(&mut afd_group)?;
+                }
+            }
+
+            match afd_group.last() {
+                Some(arc) => Ok(arc.clone()),
+                None => unreachable!(
+                    "Cannot acquire afd, {:#?}, afd_group: {:#?}",
+                    self, afd_group
+                ),
+            }
+        }
+
+        fn _alloc_afd_group(&self, afd_group: &mut Vec<Arc<Afd>>) -> io::Result<()> {
+            let afd = Afd::new(&self.cp)?;
+            let arc = Arc::new(afd);
+            afd_group.push(arc);
+            Ok(())
+        }
+    }
+}
+
+#[derive(Debug)]
+enum SockPollStatus {
+    Idle,
+    Pending,
+    Cancelled,
+}
+
+#[derive(Debug)]
+pub struct SockState {
+    iosb: IoStatusBlock,
+    poll_info: AfdPollInfo,
+    afd: Arc<Afd>,
+
+    base_socket: RawSocket,
+
+    user_evts: u32,
+    pending_evts: u32,
+
+    user_data: u64,
+
+    poll_status: SockPollStatus,
+    delete_pending: bool,
+
+    // last raw os error
+    error: Option<i32>,
+
+    _pinned: PhantomPinned,
+}
+
+impl SockState {
+    fn update(&mut self, self_arc: &Pin<Arc<Mutex<SockState>>>) -> io::Result<()> {
+        assert!(!self.delete_pending);
+
+        // make sure to reset previous error before a new update
+        self.error = None;
+
+        if let SockPollStatus::Pending = self.poll_status {
+            if (self.user_evts & afd::KNOWN_EVENTS & !self.pending_evts) == 0 {
+                /* All the events the user is interested in are already being monitored by
+                 * the pending poll operation. It might spuriously complete because of an
+                 * event that we're no longer interested in; when that happens we'll submit
+                 * a new poll operation with the updated event mask. */
+            } else {
+                /* A poll operation is already pending, but it's not monitoring for all the
+                 * events that the user is interested in. Therefore, cancel the pending
+                 * poll operation; when we receive it's completion package, a new poll
+                 * operation will be submitted with the correct event mask. */
+                if let Err(e) = self.cancel() {
+                    self.error = e.raw_os_error();
+                    return Err(e);
+                }
+                return Ok(());
+            }
+        } else if let SockPollStatus::Cancelled = self.poll_status {
+            /* The poll operation has already been cancelled, we're still waiting for
+             * it to return. For now, there's nothing that needs to be done. */
+        } else if let SockPollStatus::Idle = self.poll_status {
+            /* No poll operation is pending; start one. */
+            self.poll_info.exclusive = 0;
+            self.poll_info.number_of_handles = 1;
+            self.poll_info.timeout = i64::MAX;
+            self.poll_info.handles[0].handle = self.base_socket as HANDLE;
+            self.poll_info.handles[0].status = 0;
+            self.poll_info.handles[0].events = self.user_evts | afd::POLL_LOCAL_CLOSE;
+
+            // Increase the ref count as the memory will be used by the kernel.
+            let overlapped_ptr = into_overlapped(self_arc.clone());
+
+            let result = unsafe {
+                self.afd
+                    .poll(&mut self.poll_info, &mut *self.iosb, overlapped_ptr)
+            };
+            if let Err(e) = result {
+                let code = e.raw_os_error().unwrap();
+                if code == ERROR_IO_PENDING as i32 {
+                    /* Overlapped poll operation in progress; this is expected. */
+                } else {
+                    // Since the operation failed it means the kernel won't be
+                    // using the memory any more.
+                    drop(from_overlapped(overlapped_ptr as *mut _));
+                    if code == ERROR_INVALID_HANDLE as i32 {
+                        /* Socket closed; it'll be dropped. */
+                        self.mark_delete();
+                        return Ok(());
+                    } else {
+                        self.error = e.raw_os_error();
+                        return Err(e);
+                    }
+                }
+            }
+
+            self.poll_status = SockPollStatus::Pending;
+            self.pending_evts = self.user_evts;
+        } else {
+            unreachable!("Invalid poll status during update, {:#?}", self)
+        }
+
+        Ok(())
+    }
+
+    fn cancel(&mut self) -> io::Result<()> {
+        match self.poll_status {
+            SockPollStatus::Pending => {}
+            _ => unreachable!("Invalid poll status during cancel, {:#?}", self),
+        };
+        unsafe {
+            self.afd.cancel(&mut *self.iosb)?;
+        }
+        self.poll_status = SockPollStatus::Cancelled;
+        self.pending_evts = 0;
+        Ok(())
+    }
+
+    // This is the function called from the overlapped using as Arc<Mutex<SockState>>. Watch out for reference counting.
+    fn feed_event(&mut self) -> Option<Event> {
+        self.poll_status = SockPollStatus::Idle;
+        self.pending_evts = 0;
+
+        let mut afd_events = 0;
+        // We use the status info in IO_STATUS_BLOCK to determine the socket poll status. It is unsafe to use a pointer of IO_STATUS_BLOCK.
+        unsafe {
+            if self.delete_pending {
+                return None;
+            } else if self.iosb.Anonymous.Status == STATUS_CANCELLED {
+                /* The poll request was cancelled by CancelIoEx. */
+            } else if self.iosb.Anonymous.Status < 0 {
+                /* The overlapped request itself failed in an unexpected way. */
+                afd_events = afd::POLL_CONNECT_FAIL;
+            } else if self.poll_info.number_of_handles < 1 {
+                /* This poll operation succeeded but didn't report any socket events. */
+            } else if self.poll_info.handles[0].events & afd::POLL_LOCAL_CLOSE != 0 {
+                /* The poll operation reported that the socket was closed. */
+                self.mark_delete();
+                return None;
+            } else {
+                afd_events = self.poll_info.handles[0].events;
+            }
+        }
+
+        afd_events &= self.user_evts;
+
+        if afd_events == 0 {
+            return None;
+        }
+
+        // In mio, we have to simulate Edge-triggered behavior to match API usage.
+        // The strategy here is to intercept all read/write from user that could cause WouldBlock usage,
+        // then reregister the socket to reset the interests.
+        self.user_evts &= !afd_events;
+
+        Some(Event {
+            data: self.user_data,
+            flags: afd_events,
+        })
+    }
+
+    pub fn is_pending_deletion(&self) -> bool {
+        self.delete_pending
+    }
+
+    pub fn mark_delete(&mut self) {
+        if !self.delete_pending {
+            if let SockPollStatus::Pending = self.poll_status {
+                drop(self.cancel());
+            }
+
+            self.delete_pending = true;
+        }
+    }
+
+    fn has_error(&self) -> bool {
+        self.error.is_some()
+    }
+}
+
+cfg_io_source! {
+    impl SockState {
+        fn new(raw_socket: RawSocket, afd: Arc<Afd>) -> io::Result<SockState> {
+            Ok(SockState {
+                iosb: IoStatusBlock::zeroed(),
+                poll_info: AfdPollInfo::zeroed(),
+                afd,
+                base_socket: get_base_socket(raw_socket)?,
+                user_evts: 0,
+                pending_evts: 0,
+                user_data: 0,
+                poll_status: SockPollStatus::Idle,
+                delete_pending: false,
+                error: None,
+                _pinned: PhantomPinned,
+            })
+        }
+
+        /// True if need to be added on update queue, false otherwise.
+        fn set_event(&mut self, ev: Event) -> bool {
+            /* afd::POLL_CONNECT_FAIL and afd::POLL_ABORT are always reported, even when not requested by the caller. */
+            let events = ev.flags | afd::POLL_CONNECT_FAIL | afd::POLL_ABORT;
+
+            self.user_evts = events;
+            self.user_data = ev.data;
+
+            (events & !self.pending_evts) != 0
+        }
+    }
+}
+
+impl Drop for SockState {
+    fn drop(&mut self) {
+        self.mark_delete();
+    }
+}
+
+/// Converts the pointer to a `SockState` into a raw pointer.
+/// To revert see `from_overlapped`.
+fn into_overlapped(sock_state: Pin<Arc<Mutex<SockState>>>) -> *mut c_void {
+    let overlapped_ptr: *const Mutex<SockState> =
+        unsafe { Arc::into_raw(Pin::into_inner_unchecked(sock_state)) };
+    overlapped_ptr as *mut _
+}
+
+/// Convert a raw overlapped pointer into a reference to `SockState`.
+/// Reverts `into_overlapped`.
+fn from_overlapped(ptr: *mut OVERLAPPED) -> Pin<Arc<Mutex<SockState>>> {
+    let sock_ptr: *const Mutex<SockState> = ptr as *const _;
+    unsafe { Pin::new_unchecked(Arc::from_raw(sock_ptr)) }
+}
+
+/// Each Selector has a globally unique(ish) ID associated with it. This ID
+/// gets tracked by `TcpStream`, `TcpListener`, etc... when they are first
+/// registered with the `Selector`. If a type that is previously associated with
+/// a `Selector` attempts to register itself with a different `Selector`, the
+/// operation will return with an error. This matches windows behavior.
+#[cfg(debug_assertions)]
+static NEXT_ID: AtomicUsize = AtomicUsize::new(0);
+
+/// Windows implementation of `sys::Selector`
+///
+/// Edge-triggered event notification is simulated by resetting internal event flag of each socket state `SockState`
+/// and setting all events back by intercepting all requests that could cause `io::ErrorKind::WouldBlock` happening.
+///
+/// This selector is currently only support socket due to `Afd` driver is winsock2 specific.
+#[derive(Debug)]
+pub struct Selector {
+    #[cfg(debug_assertions)]
+    id: usize,
+    pub(super) inner: Arc<SelectorInner>,
+}
+
+impl Selector {
+    pub fn new() -> io::Result<Selector> {
+        SelectorInner::new().map(|inner| {
+            #[cfg(debug_assertions)]
+            let id = NEXT_ID.fetch_add(1, Ordering::Relaxed) + 1;
+            Selector {
+                #[cfg(debug_assertions)]
+                id,
+                inner: Arc::new(inner),
+            }
+        })
+    }
+
+    pub fn try_clone(&self) -> io::Result<Selector> {
+        Ok(Selector {
+            #[cfg(debug_assertions)]
+            id: self.id,
+            inner: Arc::clone(&self.inner),
+        })
+    }
+
+    /// # Safety
+    ///
+    /// This requires a mutable reference to self because only a single thread
+    /// can poll IOCP at a time.
+    pub fn select(&mut self, events: &mut Events, timeout: Option<Duration>) -> io::Result<()> {
+        self.inner.select(events, timeout)
+    }
+
+    pub(super) fn clone_port(&self) -> Arc<CompletionPort> {
+        self.inner.cp.clone()
+    }
+
+    #[cfg(feature = "os-ext")]
+    pub(super) fn same_port(&self, other: &Arc<CompletionPort>) -> bool {
+        Arc::ptr_eq(&self.inner.cp, other)
+    }
+}
+
+cfg_io_source! {
+    use super::InternalState;
+    use crate::Token;
+
+    impl Selector {
+        pub(super) fn register(
+            &self,
+            socket: RawSocket,
+            token: Token,
+            interests: Interest,
+        ) -> io::Result<InternalState> {
+            SelectorInner::register(&self.inner, socket, token, interests)
+        }
+
+        pub(super) fn reregister(
+            &self,
+            state: Pin<Arc<Mutex<SockState>>>,
+            token: Token,
+            interests: Interest,
+        ) -> io::Result<()> {
+            self.inner.reregister(state, token, interests)
+        }
+
+        #[cfg(debug_assertions)]
+        pub fn id(&self) -> usize {
+            self.id
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct SelectorInner {
+    pub(super) cp: Arc<CompletionPort>,
+    update_queue: Mutex<VecDeque<Pin<Arc<Mutex<SockState>>>>>,
+    afd_group: AfdGroup,
+    is_polling: AtomicBool,
+}
+
+// We have ensured thread safety by introducing lock manually.
+unsafe impl Sync for SelectorInner {}
+
+impl SelectorInner {
+    pub fn new() -> io::Result<SelectorInner> {
+        CompletionPort::new(0).map(|cp| {
+            let cp = Arc::new(cp);
+            let cp_afd = Arc::clone(&cp);
+
+            SelectorInner {
+                cp,
+                update_queue: Mutex::new(VecDeque::new()),
+                afd_group: AfdGroup::new(cp_afd),
+                is_polling: AtomicBool::new(false),
+            }
+        })
+    }
+
+    /// # Safety
+    ///
+    /// May only be calling via `Selector::select`.
+    pub fn select(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<()> {
+        events.clear();
+
+        if timeout.is_none() {
+            loop {
+                let len = self.select2(&mut events.statuses, &mut events.events, None)?;
+                if len == 0 {
+                    continue;
+                }
+                break Ok(());
+            }
+        } else {
+            self.select2(&mut events.statuses, &mut events.events, timeout)?;
+            Ok(())
+        }
+    }
+
+    pub fn select2(
+        &self,
+        statuses: &mut [CompletionStatus],
+        events: &mut Vec<Event>,
+        timeout: Option<Duration>,
+    ) -> io::Result<usize> {
+        assert!(!self.is_polling.swap(true, Ordering::AcqRel));
+
+        unsafe { self.update_sockets_events() }?;
+
+        let result = self.cp.get_many(statuses, timeout);
+
+        self.is_polling.store(false, Ordering::Relaxed);
+
+        match result {
+            Ok(iocp_events) => Ok(unsafe { self.feed_events(events, iocp_events) }),
+            Err(ref e) if e.raw_os_error() == Some(WAIT_TIMEOUT as i32) => Ok(0),
+            Err(e) => Err(e),
+        }
+    }
+
+    unsafe fn update_sockets_events(&self) -> io::Result<()> {
+        let mut update_queue = self.update_queue.lock().unwrap();
+        for sock in update_queue.iter_mut() {
+            let mut sock_internal = sock.lock().unwrap();
+            if !sock_internal.is_pending_deletion() {
+                sock_internal.update(sock)?;
+            }
+        }
+
+        // remove all sock which do not have error, they have afd op pending
+        update_queue.retain(|sock| sock.lock().unwrap().has_error());
+
+        self.afd_group.release_unused_afd();
+        Ok(())
+    }
+
+    // It returns processed count of iocp_events rather than the events itself.
+    unsafe fn feed_events(
+        &self,
+        events: &mut Vec<Event>,
+        iocp_events: &[CompletionStatus],
+    ) -> usize {
+        let mut n = 0;
+        let mut update_queue = self.update_queue.lock().unwrap();
+        for iocp_event in iocp_events.iter() {
+            if iocp_event.overlapped().is_null() {
+                events.push(Event::from_completion_status(iocp_event));
+                n += 1;
+                continue;
+            } else if iocp_event.token() % 2 == 1 {
+                // Handle is a named pipe. This could be extended to be any non-AFD event.
+                let callback = (*(iocp_event.overlapped() as *mut super::Overlapped)).callback;
+
+                let len = events.len();
+                callback(iocp_event.entry(), Some(events));
+                n += events.len() - len;
+                continue;
+            }
+
+            let sock_state = from_overlapped(iocp_event.overlapped());
+            let mut sock_guard = sock_state.lock().unwrap();
+            if let Some(e) = sock_guard.feed_event() {
+                events.push(e);
+                n += 1;
+            }
+
+            if !sock_guard.is_pending_deletion() {
+                update_queue.push_back(sock_state.clone());
+            }
+        }
+        self.afd_group.release_unused_afd();
+        n
+    }
+}
+
+cfg_io_source! {
+    use std::mem::size_of;
+    use std::ptr::null_mut;
+
+    use windows_sys::Win32::Networking::WinSock::{
+        WSAGetLastError, WSAIoctl, SIO_BASE_HANDLE, SIO_BSP_HANDLE,
+        SIO_BSP_HANDLE_POLL, SIO_BSP_HANDLE_SELECT, SOCKET_ERROR,
+    };
+
+
+    impl SelectorInner {
+        fn register(
+            this: &Arc<Self>,
+            socket: RawSocket,
+            token: Token,
+            interests: Interest,
+        ) -> io::Result<InternalState> {
+            let flags = interests_to_afd_flags(interests);
+
+            let sock = {
+                let sock = this._alloc_sock_for_rawsocket(socket)?;
+                let event = Event {
+                    flags,
+                    data: token.0 as u64,
+                };
+                sock.lock().unwrap().set_event(event);
+                sock
+            };
+
+            let state = InternalState {
+                selector: this.clone(),
+                token,
+                interests,
+                sock_state: sock.clone(),
+            };
+
+            this.queue_state(sock);
+            unsafe { this.update_sockets_events_if_polling()? };
+
+            Ok(state)
+        }
+
+        // Directly accessed in `IoSourceState::do_io`.
+        pub(super) fn reregister(
+            &self,
+            state: Pin<Arc<Mutex<SockState>>>,
+            token: Token,
+            interests: Interest,
+        ) -> io::Result<()> {
+            {
+                let event = Event {
+                    flags: interests_to_afd_flags(interests),
+                    data: token.0 as u64,
+                };
+
+                state.lock().unwrap().set_event(event);
+            }
+
+            // FIXME: a sock which has_error true should not be re-added to
+            // the update queue because it's already there.
+            self.queue_state(state);
+            unsafe { self.update_sockets_events_if_polling() }
+        }
+
+        /// This function is called by register() and reregister() to start an
+        /// IOCTL_AFD_POLL operation corresponding to the registered events, but
+        /// only if necessary.
+        ///
+        /// Since it is not possible to modify or synchronously cancel an AFD_POLL
+        /// operation, and there can be only one active AFD_POLL operation per
+        /// (socket, completion port) pair at any time, it is expensive to change
+        /// a socket's event registration after it has been submitted to the kernel.
+        ///
+        /// Therefore, if no other threads are polling when interest in a socket
+        /// event is (re)registered, the socket is added to the 'update queue', but
+        /// the actual syscall to start the IOCTL_AFD_POLL operation is deferred
+        /// until just before the GetQueuedCompletionStatusEx() syscall is made.
+        ///
+        /// However, when another thread is already blocked on
+        /// GetQueuedCompletionStatusEx() we tell the kernel about the registered
+        /// socket event(s) immediately.
+        unsafe fn update_sockets_events_if_polling(&self) -> io::Result<()> {
+            if self.is_polling.load(Ordering::Acquire) {
+                self.update_sockets_events()
+            } else {
+                Ok(())
+            }
+        }
+
+        fn queue_state(&self, sock_state: Pin<Arc<Mutex<SockState>>>) {
+            let mut update_queue = self.update_queue.lock().unwrap();
+            update_queue.push_back(sock_state);
+        }
+
+        fn _alloc_sock_for_rawsocket(
+            &self,
+            raw_socket: RawSocket,
+        ) -> io::Result<Pin<Arc<Mutex<SockState>>>> {
+            let afd = self.afd_group.acquire()?;
+            Ok(Arc::pin(Mutex::new(SockState::new(raw_socket, afd)?)))
+        }
+    }
+
+    fn try_get_base_socket(raw_socket: RawSocket, ioctl: u32) -> Result<RawSocket, i32> {
+        let mut base_socket: RawSocket = 0;
+        let mut bytes: u32 = 0;
+        unsafe {
+            if WSAIoctl(
+                raw_socket as usize,
+                ioctl,
+                null_mut(),
+                0,
+                &mut base_socket as *mut _ as *mut c_void,
+                size_of::<RawSocket>() as u32,
+                &mut bytes,
+                null_mut(),
+                None,
+            ) != SOCKET_ERROR
+            {
+                Ok(base_socket)
+            } else {
+                Err(WSAGetLastError())
+            }
+        }
+    }
+
+    fn get_base_socket(raw_socket: RawSocket) -> io::Result<RawSocket> {
+        let res = try_get_base_socket(raw_socket, SIO_BASE_HANDLE);
+        if let Ok(base_socket) = res {
+            return Ok(base_socket);
+        }
+
+        // The `SIO_BASE_HANDLE` should not be intercepted by LSPs, therefore
+        // it should not fail as long as `raw_socket` is a valid socket. See
+        // https://docs.microsoft.com/en-us/windows/win32/winsock/winsock-ioctls.
+        // However, at least one known LSP deliberately breaks it, so we try
+        // some alternative IOCTLs, starting with the most appropriate one.
+        for &ioctl in &[
+            SIO_BSP_HANDLE_SELECT,
+            SIO_BSP_HANDLE_POLL,
+            SIO_BSP_HANDLE,
+        ] {
+            if let Ok(base_socket) = try_get_base_socket(raw_socket, ioctl) {
+                // Since we know now that we're dealing with an LSP (otherwise
+                // SIO_BASE_HANDLE wouldn't have failed), only return any result
+                // when it is different from the original `raw_socket`.
+                if base_socket != raw_socket {
+                    return Ok(base_socket);
+                }
+            }
+        }
+
+        // If the alternative IOCTLs also failed, return the original error.
+        let os_error = res.unwrap_err();
+        let err = io::Error::from_raw_os_error(os_error);
+        Err(err)
+    }
+}
+
+impl Drop for SelectorInner {
+    fn drop(&mut self) {
+        loop {
+            let events_num: usize;
+            let mut statuses: [CompletionStatus; 1024] = [CompletionStatus::zero(); 1024];
+
+            let result = self
+                .cp
+                .get_many(&mut statuses, Some(std::time::Duration::from_millis(0)));
+            match result {
+                Ok(iocp_events) => {
+                    events_num = iocp_events.iter().len();
+                    for iocp_event in iocp_events.iter() {
+                        if iocp_event.overlapped().is_null() {
+                            // Custom event
+                        } else if iocp_event.token() % 2 == 1 {
+                            // Named pipe, dispatch the event so it can release resources
+                            let callback = unsafe {
+                                (*(iocp_event.overlapped() as *mut super::Overlapped)).callback
+                            };
+
+                            callback(iocp_event.entry(), None);
+                        } else {
+                            // drain sock state to release memory of Arc reference
+                            let _sock_state = from_overlapped(iocp_event.overlapped());
+                        }
+                    }
+                }
+
+                Err(_) => {
+                    break;
+                }
+            }
+
+            if events_num == 0 {
+                // continue looping until all completion statuses have been drained
+                break;
+            }
+        }
+
+        self.afd_group.release_unused_afd();
+    }
+}
+
+cfg_net! {
+    fn interests_to_afd_flags(interests: Interest) -> u32 {
+        let mut flags = 0;
+
+        if interests.is_readable() {
+            flags |= READABLE_FLAGS | READ_CLOSED_FLAGS | ERROR_FLAGS;
+        }
+
+        if interests.is_writable() {
+            flags |= WRITABLE_FLAGS | WRITE_CLOSED_FLAGS | ERROR_FLAGS;
+        }
+
+        flags
+    }
+}

vendor/mio/src/sys/windows/tcp.rs

@@ -0,0 +1,64 @@
+use std::io;
+use std::net::{self, SocketAddr};
+use std::os::windows::io::AsRawSocket;
+
+use windows_sys::Win32::Networking::WinSock::{self, SOCKET, SOCKET_ERROR, SOCK_STREAM};
+
+use crate::sys::windows::net::{new_ip_socket, socket_addr};
+
+pub(crate) fn new_for_addr(address: SocketAddr) -> io::Result<SOCKET> {
+    new_ip_socket(address, SOCK_STREAM)
+}
+
+pub(crate) fn bind(socket: &net::TcpListener, addr: SocketAddr) -> io::Result<()> {
+    use WinSock::bind;
+
+    let (raw_addr, raw_addr_length) = socket_addr(&addr);
+    syscall!(
+        bind(
+            socket.as_raw_socket() as _,
+            raw_addr.as_ptr(),
+            raw_addr_length
+        ),
+        PartialEq::eq,
+        SOCKET_ERROR
+    )?;
+    Ok(())
+}
+
+pub(crate) fn connect(socket: &net::TcpStream, addr: SocketAddr) -> io::Result<()> {
+    use WinSock::connect;
+
+    let (raw_addr, raw_addr_length) = socket_addr(&addr);
+    let res = syscall!(
+        connect(
+            socket.as_raw_socket() as _,
+            raw_addr.as_ptr(),
+            raw_addr_length
+        ),
+        PartialEq::eq,
+        SOCKET_ERROR
+    );
+
+    match res {
+        Err(err) if err.kind() != io::ErrorKind::WouldBlock => Err(err),
+        _ => Ok(()),
+    }
+}
+
+pub(crate) fn listen(socket: &net::TcpListener, backlog: i32) -> io::Result<()> {
+    use WinSock::listen;
+
+    syscall!(
+        listen(socket.as_raw_socket() as _, backlog),
+        PartialEq::eq,
+        SOCKET_ERROR
+    )?;
+    Ok(())
+}
+
+pub(crate) fn accept(listener: &net::TcpListener) -> io::Result<(net::TcpStream, SocketAddr)> {
+    // The non-blocking state of `listener` is inherited. See
+    // https://docs.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-accept#remarks.
+    listener.accept()
+}

vendor/mio/src/sys/windows/udp.rs

@@ -0,0 +1,46 @@
+use std::io;
+use std::mem::{self, MaybeUninit};
+use std::net::{self, SocketAddr};
+use std::os::windows::io::{AsRawSocket, FromRawSocket};
+use std::os::windows::raw::SOCKET as StdSocket; // windows-sys uses usize, stdlib uses u32/u64.
+
+use crate::sys::windows::net::{new_ip_socket, socket_addr};
+use windows_sys::Win32::Networking::WinSock::{
+    bind as win_bind, getsockopt, IPPROTO_IPV6, IPV6_V6ONLY, SOCKET_ERROR, SOCK_DGRAM,
+};
+
+pub fn bind(addr: SocketAddr) -> io::Result<net::UdpSocket> {
+    let raw_socket = new_ip_socket(addr, SOCK_DGRAM)?;
+    let socket = unsafe { net::UdpSocket::from_raw_socket(raw_socket as StdSocket) };
+
+    let (raw_addr, raw_addr_length) = socket_addr(&addr);
+    syscall!(
+        win_bind(raw_socket, raw_addr.as_ptr(), raw_addr_length),
+        PartialEq::eq,
+        SOCKET_ERROR
+    )?;
+
+    Ok(socket)
+}
+
+pub(crate) fn only_v6(socket: &net::UdpSocket) -> io::Result<bool> {
+    let mut optval: MaybeUninit<i32> = MaybeUninit::uninit();
+    let mut optlen = mem::size_of::<i32>() as i32;
+
+    syscall!(
+        getsockopt(
+            socket.as_raw_socket() as usize,
+            IPPROTO_IPV6 as i32,
+            IPV6_V6ONLY as i32,
+            optval.as_mut_ptr().cast(),
+            &mut optlen,
+        ),
+        PartialEq::eq,
+        SOCKET_ERROR
+    )?;
+
+    debug_assert_eq!(optlen as usize, mem::size_of::<i32>());
+    // Safety: `getsockopt` initialised `optval` for us.
+    let optval = unsafe { optval.assume_init() };
+    Ok(optval != 0)
+}

vendor/mio/src/sys/windows/waker.rs

@@ -0,0 +1,29 @@
+use crate::sys::windows::Event;
+use crate::sys::windows::Selector;
+use crate::Token;
+
+use super::iocp::CompletionPort;
+use std::io;
+use std::sync::Arc;
+
+#[derive(Debug)]
+pub struct Waker {
+    token: Token,
+    port: Arc<CompletionPort>,
+}
+
+impl Waker {
+    pub fn new(selector: &Selector, token: Token) -> io::Result<Waker> {
+        Ok(Waker {
+            token,
+            port: selector.clone_port(),
+        })
+    }
+
+    pub fn wake(&self) -> io::Result<()> {
+        let mut ev = Event::new(self.token);
+        ev.set_readable();
+
+        self.port.post(ev.to_completion_status())
+    }
+}