diff options
Diffstat (limited to 'src/sys/unix/selector/kqueue.rs')
| -rw-r--r-- | src/sys/unix/selector/kqueue.rs | 676 |
1 files changed, 676 insertions, 0 deletions
diff --git a/src/sys/unix/selector/kqueue.rs b/src/sys/unix/selector/kqueue.rs new file mode 100644 index 0000000..2ebac9a --- /dev/null +++ b/src/sys/unix/selector/kqueue.rs @@ -0,0 +1,676 @@ +use crate::{Interest, Token}; +use log::error; +use std::mem::MaybeUninit; +use std::ops::{Deref, DerefMut}; +use std::os::unix::io::{AsRawFd, RawFd}; +#[cfg(debug_assertions)] +use std::sync::atomic::{AtomicUsize, Ordering}; +use std::time::Duration; +use std::{cmp, io, ptr, slice}; + +/// 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 = "freebsd", target_os = "openbsd"))] +type Filter = libc::c_short; +#[cfg(any(target_os = "macos", target_os = "ios"))] +type Filter = i16; +#[cfg(target_os = "netbsd")] +type Filter = u32; + +// Type of the `flags` field in the `kevent` structure. +#[cfg(any(target_os = "freebsd", target_os = "openbsd"))] +type Flags = libc::c_ushort; +#[cfg(any(target_os = "macos", target_os = "ios"))] +type Flags = u16; +#[cfg(target_os = "netbsd")] +type Flags = u32; + +// Type of the `data` field in the `kevent` structure. +#[cfg(any( + target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "macos" +))] +type Data = libc::intptr_t; +#[cfg(any(target_os = "netbsd", target_os = "openbsd"))] +type Data = i64; + +// Type of the `udata` field in the `kevent` structure. +#[cfg(not(target_os = "netbsd"))] +type UData = *mut libc::c_void; +#[cfg(target_os = "netbsd")] +type UData = libc::intptr_t; + +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, + fflags: 0, + data: 0, + udata: $data as UData, + } + }; +} + +#[derive(Debug)] +pub struct Selector { + #[cfg(debug_assertions)] + id: usize, + kq: RawFd, +} + +impl Selector { + pub fn new() -> io::Result<Selector> { + syscall!(kqueue()) + .and_then(|kq| syscall!(fcntl(kq, libc::F_SETFD, libc::FD_CLOEXEC)).map(|_| kq)) + .map(|kq| Selector { + #[cfg(debug_assertions)] + id: NEXT_ID.fetch_add(1, Ordering::Relaxed), + kq, + }) + } + + pub fn try_clone(&self) -> io::Result<Selector> { + syscall!(dup(self.kq)).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_value() 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, + ptr::null(), + 0, + events.as_mut_ptr(), + 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) }; + }) + } + + 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, changes, &[libc::EPIPE as Data]) + } + + 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, + &mut changes, + &[libc::ENOENT as Data, libc::EPIPE as Data], + ) + } + + 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, &mut changes, &[libc::ENOENT as Data]) + } + + // Used by `Waker`. + #[cfg(any(target_os = "freebsd", target_os = "ios", target_os = "macos"))] + 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 + ); + + syscall!(kevent(self.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"))] + 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; + + syscall!(kevent(self.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: &[Data], +) -> 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: &[Data]) -> 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; + // 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_net! { + #[cfg(debug_assertions)] + impl Selector { + pub fn id(&self) -> usize { + self.id + } + } +} + +impl AsRawFd for Selector { + fn as_raw_fd(&self) -> RawFd { + self.kq + } +} + +impl Drop for Selector { + fn drop(&mut self) { + if let Err(err) = syscall!(close(self.kq)) { + error!("error closing kqueue: {}", err); + } + } +} + +pub type Event = libc::kevent; +pub struct Events(Vec<libc::kevent>); + +impl Events { + pub fn with_capacity(capacity: usize) -> Events { + Events(Vec::with_capacity(capacity)) + } +} + +impl Deref for Events { + type Target = Vec<libc::kevent>; + + fn deref(&self) -> &Self::Target { + &self.0 + } +} + +impl DerefMut for Events { + fn deref_mut(&mut self) -> &mut Self::Target { + &mut self.0 + } +} + +// `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.udata as usize) + } + + pub fn is_readable(event: &Event) -> bool { + event.filter == libc::EVFILT_READ || { + #[cfg(any(target_os = "freebsd", target_os = "ios", target_os = "macos"))] + // 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")))] + { + false + } + } + } + + pub fn is_writable(event: &Event) -> bool { + event.filter == libc::EVFILT_WRITE + } + + pub fn is_error(event: &Event) -> bool { + (event.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.flags & libc::EV_EOF) != 0 && event.fflags != 0 + } + + pub fn is_read_closed(event: &Event) -> bool { + event.filter == libc::EVFILT_READ && event.flags & libc::EV_EOF != 0 + } + + pub fn is_write_closed(event: &Event) -> bool { + event.filter == libc::EVFILT_WRITE && event.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" + ))] + { + event.filter == libc::EVFILT_AIO + } + #[cfg(not(any( + target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "macos" + )))] + { + false + } + } + + #[allow(unused_variables)] // `event` is only used on FreeBSD. + pub fn is_lio(event: &Event) -> bool { + #[cfg(target_os = "freebsd")] + { + event.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" + ))] + libc::EVFILT_FS, + #[cfg(target_os = "freebsd")] + libc::EVFILT_LIO, + #[cfg(any( + target_os = "freebsd", + target_os = "dragonfly", + target_os = "ios", + target_os = "macos" + ))] + 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"))] + libc::EVFILT_MACHPORT, + #[cfg(any(target_os = "ios", target_os = "macos"))] + 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, + libc::EV_SYSFLAGS, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::EV_FLAG0, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::EV_POLL, + #[cfg(any(target_os = "ios", target_os = "macos"))] + 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" + ))] + libc::NOTE_TRIGGER, + #[cfg(any( + target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "macos" + ))] + libc::NOTE_FFNOP, + #[cfg(any( + target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "macos" + ))] + libc::NOTE_FFAND, + #[cfg(any( + target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "macos" + ))] + libc::NOTE_FFOR, + #[cfg(any( + target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "macos" + ))] + libc::NOTE_FFCOPY, + #[cfg(any( + target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "macos" + ))] + libc::NOTE_FFCTRLMASK, + #[cfg(any( + target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "macos" + ))] + 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"))] + libc::NOTE_EXTEND, + libc::NOTE_ATTRIB, + libc::NOTE_LINK, + libc::NOTE_RENAME, + libc::NOTE_REVOKE, + #[cfg(any(target_os = "ios", target_os = "macos"))] + 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"))] + libc::NOTE_SIGNAL, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_EXITSTATUS, + #[cfg(any(target_os = "ios", target_os = "macos"))] + 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"))] + libc::NOTE_EXIT_DETAIL_MASK, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_EXIT_DECRYPTFAIL, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_EXIT_MEMORY, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_EXIT_CSERROR, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_VM_PRESSURE, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_VM_PRESSURE_TERMINATE, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_VM_PRESSURE_SUDDEN_TERMINATE, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_VM_ERROR, + #[cfg(any(target_os = "freebsd", target_os = "ios", target_os = "macos"))] + libc::NOTE_SECONDS, + #[cfg(any(target_os = "freebsd"))] + libc::NOTE_MSECONDS, + #[cfg(any(target_os = "freebsd", target_os = "ios", target_os = "macos"))] + libc::NOTE_USECONDS, + #[cfg(any(target_os = "freebsd", target_os = "ios", target_os = "macos"))] + libc::NOTE_NSECONDS, + #[cfg(any(target_os = "ios", target_os = "macos"))] + #[cfg(any(target_os = "freebsd", target_os = "ios", target_os = "macos"))] + libc::NOTE_ABSOLUTE, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_LEEWAY, + #[cfg(any(target_os = "ios", target_os = "macos"))] + libc::NOTE_CRITICAL, + #[cfg(any(target_os = "dragonfly"))] + libc::NOTE_BACKGROUND, + ); + + // Can't reference fields in packed structures. + let ident = event.ident; + let data = event.data; + let udata = event.udata; + f.debug_struct("kevent") + .field("ident", &ident) + .field("filter", &FilterDetails(event.filter)) + .field("flags", &FlagsDetails(event.flags)) + .field("fflags", &FflagsDetails(event.fflags)) + .field("data", &data) + .field("udata", &udata) + .finish() + } +} + +#[test] +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(); +} |