alioth/src/sync/notifier/notifier_macos.rs - 02504ad

notifier_macos.rs92.16%

// Copyright 2025 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
use std::fs::File;
use std::io::{ErrorKind, Result};
use std::os::fd::{FromRawFd, OwnedFd};
use std::os::unix::io::AsRawFd;
use std::ptr::{null, null_mut};
 
use mio::event::Source;
use mio::{Interest, Registry, Token};
 
use crate::ffi;
 
#[derive(Debug)]
pub struct Notifier {
    fd: OwnedFd,
    registered: Option<(Token, OwnedFd)>,
}
 
impl Notifier {
    pub fn new() -> Result<Self> {12x
        Ok(Notifier {
            fd: File::open("/dev/null")?.into(),12x
            registered: None,12x
        })
    }12x
 
    pub fn notify(&self) -> Result<()> {21x
        let Some((token, kqfd)) = &self.registered else {21x
            return Err(ErrorKind::NotFound.into());
        };
        let event = libc::kevent {21x
            ident: self.fd.as_raw_fd() as _,21x
            filter: libc::EVFILT_USER,21x
            flags: libc::EV_ADD | libc::EV_RECEIPT,21x
            fflags: libc::NOTE_TRIGGER,21x
            data: 0,21x
            udata: token.0 as _,21x
        };21x
        ffi!(unsafe { libc::kevent(kqfd.as_raw_fd(), &event, 1, null_mut(), 0, null()) })?;21x
        Ok(())21x
    }21x
}
 
impl Source for Notifier {
    fn register(&mut self, registry: &Registry, token: Token, _: Interest) -> Result<()> {12x
        let event = libc::kevent {12x
            ident: self.fd.as_raw_fd() as _,12x
            filter: libc::EVFILT_USER,12x
            flags: libc::EV_ADD | libc::EV_CLEAR | libc::EV_RECEIPT,12x
            fflags: 0,12x
            data: 0,12x
            udata: null_mut(),12x
        };12x
 
        let kqfd = registry.as_raw_fd();12x
        let kqfd = ffi!(unsafe { libc::dup(kqfd) })?;12x
        let kqfd = unsafe { OwnedFd::from_raw_fd(kqfd) };12x
 
        ffi!(unsafe { libc::kevent(kqfd.as_raw_fd(), &event, 1, null_mut(), 0, null()) })?;12x
        self.registered = Some((token, kqfd));12x
        Ok(())12x
    }12x
 
    fn deregister(&mut self, registry: &Registry) -> Result<()> {2x
        let event = libc::kevent {2x
            ident: self.fd.as_raw_fd() as _,2x
            filter: libc::EVFILT_USER,2x
            flags: libc::EV_DELETE | libc::EV_RECEIPT,2x
            fflags: 0,2x
            data: 0,2x
            udata: null_mut(),2x
        };2x
 
        let kqfd = registry.as_raw_fd();2x
 
        ffi!(unsafe { libc::kevent(kqfd, &event, 1, null_mut(), 0, null()) })?;2x
        self.registered = None;2x
        Ok(())2x
    }2x
 
    fn reregister(&mut self, _: &Registry, _: Token, _: Interest) -> Result<()> {
        Err(ErrorKind::Unsupported.into())
    }
}
 