aboutsummaryrefslogtreecommitdiff
path: root/vendor/rustix/src/backend/linux_raw/event/epoll.rs
diff options
context:
space:
mode:
authorValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
committerValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
commit1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch)
tree7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/rustix/src/backend/linux_raw/event/epoll.rs
parent5ecd8cf2cba827454317368b68571df0d13d7842 (diff)
downloadfparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz
fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/rustix/src/backend/linux_raw/event/epoll.rs')
-rw-r--r--vendor/rustix/src/backend/linux_raw/event/epoll.rs470
1 files changed, 470 insertions, 0 deletions
diff --git a/vendor/rustix/src/backend/linux_raw/event/epoll.rs b/vendor/rustix/src/backend/linux_raw/event/epoll.rs
new file mode 100644
index 0000000..3d5787b
--- /dev/null
+++ b/vendor/rustix/src/backend/linux_raw/event/epoll.rs
@@ -0,0 +1,470 @@
+//! Linux `epoll` support.
+//!
+//! # Examples
+//!
+//! ```no_run
+//! # #[cfg(feature = "net")]
+//! # fn main() -> std::io::Result<()> {
+//! use rustix::event::epoll;
+//! use rustix::fd::AsFd;
+//! use rustix::io::{ioctl_fionbio, read, write};
+//! use rustix::net::{
+//! accept, bind_v4, listen, socket, AddressFamily, Ipv4Addr, SocketAddrV4, SocketType,
+//! };
+//! use std::collections::HashMap;
+//! use std::os::unix::io::AsRawFd;
+//!
+//! // Create a socket and listen on it.
+//! let listen_sock = socket(AddressFamily::INET, SocketType::STREAM, None)?;
+//! bind_v4(&listen_sock, &SocketAddrV4::new(Ipv4Addr::LOCALHOST, 0))?;
+//! listen(&listen_sock, 1)?;
+//!
+//! // Create an epoll object. Using `Owning` here means the epoll object will
+//! // take ownership of the file descriptors registered with it.
+//! let epoll = epoll::create(epoll::CreateFlags::CLOEXEC)?;
+//!
+//! // Register the socket with the epoll object.
+//! epoll::add(
+//! &epoll,
+//! &listen_sock,
+//! epoll::EventData::new_u64(1),
+//! epoll::EventFlags::IN,
+//! )?;
+//!
+//! // Keep track of the sockets we've opened.
+//! let mut next_id = epoll::EventData::new_u64(2);
+//! let mut sockets = HashMap::new();
+//!
+//! // Process events.
+//! let mut event_list = epoll::EventVec::with_capacity(4);
+//! loop {
+//! epoll::wait(&epoll, &mut event_list, -1)?;
+//! for event in &event_list {
+//! let target = event.data;
+//! if target.u64() == 1 {
+//! // Accept a new connection, set it to non-blocking, and
+//! // register to be notified when it's ready to write to.
+//! let conn_sock = accept(&listen_sock)?;
+//! ioctl_fionbio(&conn_sock, true)?;
+//! epoll::add(
+//! &epoll,
+//! &conn_sock,
+//! next_id,
+//! epoll::EventFlags::OUT | epoll::EventFlags::ET,
+//! )?;
+//!
+//! // Keep track of the socket.
+//! sockets.insert(next_id, conn_sock);
+//! next_id = epoll::EventData::new_u64(next_id.u64() + 1);
+//! } else {
+//! // Write a message to the stream and then unregister it.
+//! let target = sockets.remove(&target).unwrap();
+//! write(&target, b"hello\n")?;
+//! let _ = epoll::delete(&epoll, &target)?;
+//! }
+//! }
+//! }
+//! # }
+//! # #[cfg(not(feature = "net"))]
+//! # fn main() {}
+//! ```
+
+#![allow(unsafe_code)]
+
+use crate::backend::c;
+use crate::backend::event::syscalls;
+use crate::fd::{AsFd, AsRawFd, OwnedFd};
+use crate::io;
+#[cfg(feature = "alloc")]
+use alloc::vec::Vec;
+use bitflags::bitflags;
+use core::ffi::c_void;
+use core::hash::{Hash, Hasher};
+use core::slice;
+
+bitflags! {
+ /// `EPOLL_*` for use with [`new`].
+ #[repr(transparent)]
+ #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+ pub struct CreateFlags: c::c_uint {
+ /// `EPOLL_CLOEXEC`
+ const CLOEXEC = linux_raw_sys::general::EPOLL_CLOEXEC;
+
+ /// <https://docs.rs/bitflags/*/bitflags/#externally-defined-flags>
+ const _ = !0;
+ }
+}
+
+bitflags! {
+ /// `EPOLL*` for use with [`add`].
+ #[repr(transparent)]
+ #[derive(Default, Copy, Clone, Eq, PartialEq, Hash, Debug)]
+ pub struct EventFlags: u32 {
+ /// `EPOLLIN`
+ const IN = linux_raw_sys::general::EPOLLIN as u32;
+
+ /// `EPOLLOUT`
+ const OUT = linux_raw_sys::general::EPOLLOUT as u32;
+
+ /// `EPOLLPRI`
+ const PRI = linux_raw_sys::general::EPOLLPRI as u32;
+
+ /// `EPOLLERR`
+ const ERR = linux_raw_sys::general::EPOLLERR as u32;
+
+ /// `EPOLLHUP`
+ const HUP = linux_raw_sys::general::EPOLLHUP as u32;
+
+ /// `EPOLLRDNORM`
+ const RDNORM = linux_raw_sys::general::EPOLLRDNORM as u32;
+
+ /// `EPOLLRDBAND`
+ const RDBAND = linux_raw_sys::general::EPOLLRDBAND as u32;
+
+ /// `EPOLLWRNORM`
+ const WRNORM = linux_raw_sys::general::EPOLLWRNORM as u32;
+
+ /// `EPOLLWRBAND`
+ const WRBAND = linux_raw_sys::general::EPOLLWRBAND as u32;
+
+ /// `EPOLLMSG`
+ const MSG = linux_raw_sys::general::EPOLLMSG as u32;
+
+ /// `EPOLLRDHUP`
+ const RDHUP = linux_raw_sys::general::EPOLLRDHUP as u32;
+
+ /// `EPOLLET`
+ const ET = linux_raw_sys::general::EPOLLET as u32;
+
+ /// `EPOLLONESHOT`
+ const ONESHOT = linux_raw_sys::general::EPOLLONESHOT as u32;
+
+ /// `EPOLLWAKEUP`
+ const WAKEUP = linux_raw_sys::general::EPOLLWAKEUP as u32;
+
+ /// `EPOLLEXCLUSIVE`
+ const EXCLUSIVE = linux_raw_sys::general::EPOLLEXCLUSIVE as u32;
+
+ /// <https://docs.rs/bitflags/*/bitflags/#externally-defined-flags>
+ const _ = !0;
+ }
+}
+
+/// `epoll_create1(flags)`—Creates a new epoll object.
+///
+/// Use the [`CreateFlags::CLOEXEC`] flag to prevent the resulting file
+/// descriptor from being implicitly passed across `exec` boundaries.
+#[inline]
+#[doc(alias = "epoll_create1")]
+pub fn create(flags: CreateFlags) -> io::Result<OwnedFd> {
+ syscalls::epoll_create(flags)
+}
+
+/// `epoll_ctl(self, EPOLL_CTL_ADD, data, event)`—Adds an element to an epoll
+/// object.
+///
+/// This registers interest in any of the events set in `events` occurring on
+/// the file descriptor associated with `data`.
+///
+/// If [`delete`] is not called on the I/O source passed into this function
+/// before the I/O source is `close`d, then the `epoll` will act as if the I/O
+/// source is still registered with it. This can lead to spurious events being
+/// returned from [`wait`]. If a file descriptor is an
+/// `Arc<dyn SystemResource>`, then `epoll` can be thought to maintain a
+/// `Weak<dyn SystemResource>` to the file descriptor.
+#[doc(alias = "epoll_ctl")]
+#[inline]
+pub fn add(
+ epoll: impl AsFd,
+ source: impl AsFd,
+ data: EventData,
+ event_flags: EventFlags,
+) -> io::Result<()> {
+ // SAFETY: We're calling `epoll_ctl` via FFI and we know how it
+ // behaves.
+ unsafe {
+ syscalls::epoll_add(
+ epoll.as_fd(),
+ source.as_fd().as_raw_fd(),
+ &Event {
+ flags: event_flags,
+ data,
+ },
+ )
+ }
+}
+
+/// `epoll_ctl(self, EPOLL_CTL_MOD, target, event)`—Modifies an element in a
+/// given epoll object.
+///
+/// This sets the events of interest with `target` to `events`.
+#[doc(alias = "epoll_ctl")]
+#[inline]
+pub fn modify(
+ epoll: impl AsFd,
+ source: impl AsFd,
+ data: EventData,
+ event_flags: EventFlags,
+) -> io::Result<()> {
+ // SAFETY: We're calling `epoll_ctl` via FFI and we know how it
+ // behaves.
+ unsafe {
+ let raw_fd = source.as_fd().as_raw_fd();
+ syscalls::epoll_mod(
+ epoll.as_fd(),
+ raw_fd,
+ &Event {
+ flags: event_flags,
+ data,
+ },
+ )
+ }
+}
+
+/// `epoll_ctl(self, EPOLL_CTL_DEL, target, NULL)`—Removes an element in a
+/// given epoll object.
+#[doc(alias = "epoll_ctl")]
+#[inline]
+pub fn delete(epoll: impl AsFd, source: impl AsFd) -> io::Result<()> {
+ // SAFETY: We're calling `epoll_ctl` via FFI and we know how it
+ // behaves.
+ unsafe {
+ let raw_fd = source.as_fd().as_raw_fd();
+ syscalls::epoll_del(epoll.as_fd(), raw_fd)
+ }
+}
+
+/// `epoll_wait(self, events, timeout)`—Waits for registered events of
+/// interest.
+///
+/// For each event of interest, an element is written to `events`. On
+/// success, this returns the number of written elements.
+#[cfg(feature = "alloc")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "alloc")))]
+#[inline]
+pub fn wait(epoll: impl AsFd, event_list: &mut EventVec, timeout: c::c_int) -> io::Result<()> {
+ // SAFETY: We're calling `epoll_wait` via FFI and we know how it
+ // behaves.
+ unsafe {
+ event_list.events.set_len(0);
+ let nfds = syscalls::epoll_wait(
+ epoll.as_fd(),
+ event_list.events[..].as_mut_ptr().cast(),
+ event_list.events.capacity(),
+ timeout,
+ )?;
+ event_list.events.set_len(nfds);
+ }
+
+ Ok(())
+}
+
+/// An iterator over the `Event`s in an `EventVec`.
+pub struct Iter<'a> {
+ /// Use `Copied` to copy the struct, since `Event` is `packed` on some
+ /// platforms, and it's common for users to directly destructure it, which
+ /// would lead to errors about forming references to packed fields.
+ iter: core::iter::Copied<slice::Iter<'a, Event>>,
+}
+
+impl<'a> Iterator for Iter<'a> {
+ type Item = Event;
+
+ #[inline]
+ fn next(&mut self) -> Option<Self::Item> {
+ self.iter.next()
+ }
+}
+
+/// A record of an event that occurred.
+#[repr(C)]
+#[cfg_attr(target_arch = "x86_64", repr(packed))]
+#[derive(Copy, Clone, Eq, PartialEq, Hash)]
+pub struct Event {
+ /// Which specific event(s) occurred.
+ pub flags: EventFlags,
+ /// User data.
+ pub data: EventData,
+}
+
+/// Data associated with an [`Event`]. This can either be a 64-bit integer
+/// value or a pointer which preserves pointer provenance.
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub union EventData {
+ /// A 64-bit integer value.
+ as_u64: u64,
+
+ /// A `*mut c_void` which preserves pointer provenance, extended to be
+ /// 64-bit so that if we read the value as a `u64` union field, we don't
+ /// get uninitialized memory.
+ sixty_four_bit_pointer: SixtyFourBitPointer,
+}
+
+impl EventData {
+ /// Construct a new value containing a `u64`.
+ #[inline]
+ pub const fn new_u64(value: u64) -> Self {
+ Self { as_u64: value }
+ }
+
+ /// Construct a new value containing a `*mut c_void`.
+ #[inline]
+ pub const fn new_ptr(value: *mut c_void) -> Self {
+ Self {
+ sixty_four_bit_pointer: SixtyFourBitPointer {
+ pointer: value,
+ #[cfg(target_pointer_width = "32")]
+ _padding: 0,
+ },
+ }
+ }
+
+ /// Return the value as a `u64`.
+ ///
+ /// If the stored value was a pointer, the pointer is zero-extended to a
+ /// `u64`.
+ #[inline]
+ pub fn u64(self) -> u64 {
+ unsafe { self.as_u64 }
+ }
+
+ /// Return the value as a `*mut c_void`.
+ ///
+ /// If the stored value was a `u64`, the least-significant bits of the
+ /// `u64` are returned as a pointer value.
+ #[inline]
+ pub fn ptr(self) -> *mut c_void {
+ unsafe { self.sixty_four_bit_pointer.pointer }
+ }
+}
+
+impl PartialEq for EventData {
+ #[inline]
+ fn eq(&self, other: &Self) -> bool {
+ self.u64() == other.u64()
+ }
+}
+
+impl Eq for EventData {}
+
+impl Hash for EventData {
+ #[inline]
+ fn hash<H: Hasher>(&self, state: &mut H) {
+ self.u64().hash(state)
+ }
+}
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+struct SixtyFourBitPointer {
+ #[cfg(target_endian = "big")]
+ #[cfg(target_pointer_width = "32")]
+ _padding: u32,
+
+ pointer: *mut c_void,
+
+ #[cfg(target_endian = "little")]
+ #[cfg(target_pointer_width = "32")]
+ _padding: u32,
+}
+
+/// A vector of `Event`s, plus context for interpreting them.
+#[cfg(feature = "alloc")]
+pub struct EventVec {
+ events: Vec<Event>,
+}
+
+#[cfg(feature = "alloc")]
+impl EventVec {
+ /// Constructs an `EventVec` from raw pointer, length, and capacity.
+ ///
+ /// # Safety
+ ///
+ /// This function calls [`Vec::from_raw_parts`] with its arguments.
+ ///
+ /// [`Vec::from_raw_parts`]: https://doc.rust-lang.org/stable/std/vec/struct.Vec.html#method.from_raw_parts
+ #[inline]
+ pub unsafe fn from_raw_parts(ptr: *mut Event, len: usize, capacity: usize) -> Self {
+ Self {
+ events: Vec::from_raw_parts(ptr, len, capacity),
+ }
+ }
+
+ /// Constructs an `EventVec` with memory for `capacity` `Event`s.
+ #[inline]
+ pub fn with_capacity(capacity: usize) -> Self {
+ Self {
+ events: Vec::with_capacity(capacity),
+ }
+ }
+
+ /// Returns the current `Event` capacity of this `EventVec`.
+ #[inline]
+ pub fn capacity(&self) -> usize {
+ self.events.capacity()
+ }
+
+ /// Reserves enough memory for at least `additional` more `Event`s.
+ #[inline]
+ pub fn reserve(&mut self, additional: usize) {
+ self.events.reserve(additional);
+ }
+
+ /// Reserves enough memory for exactly `additional` more `Event`s.
+ #[inline]
+ pub fn reserve_exact(&mut self, additional: usize) {
+ self.events.reserve_exact(additional);
+ }
+
+ /// Clears all the `Events` out of this `EventVec`.
+ #[inline]
+ pub fn clear(&mut self) {
+ self.events.clear();
+ }
+
+ /// Shrinks the capacity of this `EventVec` as much as possible.
+ #[inline]
+ pub fn shrink_to_fit(&mut self) {
+ self.events.shrink_to_fit();
+ }
+
+ /// Returns an iterator over the `Event`s in this `EventVec`.
+ #[inline]
+ pub fn iter(&self) -> Iter<'_> {
+ Iter {
+ iter: self.events.iter().copied(),
+ }
+ }
+
+ /// Returns the number of `Event`s logically contained in this `EventVec`.
+ #[inline]
+ pub fn len(&mut self) -> usize {
+ self.events.len()
+ }
+
+ /// Tests whether this `EventVec` is logically empty.
+ #[inline]
+ pub fn is_empty(&mut self) -> bool {
+ self.events.is_empty()
+ }
+}
+
+#[cfg(feature = "alloc")]
+impl<'a> IntoIterator for &'a EventVec {
+ type IntoIter = Iter<'a>;
+ type Item = Event;
+
+ #[inline]
+ fn into_iter(self) -> Self::IntoIter {
+ self.iter()
+ }
+}
+
+#[test]
+fn test_epoll_layouts() {
+ check_renamed_type!(Event, epoll_event);
+ check_renamed_type!(Event, epoll_event);
+ check_renamed_struct_renamed_field!(Event, epoll_event, flags, events);
+ check_renamed_struct_renamed_field!(Event, epoll_event, data, data);
+}