diff --git a/CHANGELOG.md b/CHANGELOG.md index 916649d23a..465d2829c2 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -43,6 +43,8 @@ This project adheres to [Semantic Versioning](https://semver.org/). ### Changed +- The epoll interface now uses a type. + ([#1882](https://github.com/nix-rust/nix/pull/1882)) - The MSRV is now 1.63.0 ([#1882](https://github.com/nix-rust/nix/pull/1882)) - The `addr` argument of `sys::mman::mmap` is now of type `Option`. diff --git a/src/sys/epoll.rs b/src/sys/epoll.rs index 58def2e788..8f254d29ed 100644 --- a/src/sys/epoll.rs +++ b/src/sys/epoll.rs @@ -2,8 +2,7 @@ use crate::errno::Errno; use crate::Result; use libc::{self, c_int}; use std::mem; -use std::os::unix::io::RawFd; -use std::ptr; +use std::os::unix::io::{FromRawFd,RawFd, OwnedFd, AsFd, AsRawFd}; libc_bitflags!( pub struct EpollFlags: c_int { @@ -26,6 +25,107 @@ libc_bitflags!( } ); +/// A safe wrapper around [`epoll`](https://man7.org/linux/man-pages/man7/epoll.7.html). +/// ``` +/// # use nix::sys::{epoll::{Epoll, EpollEvent, EpollFlags, EpollCreateFlags}, eventfd::{eventfd, EfdFlags}}; +/// # use nix::unistd::write; +/// # use std::os::unix::io::{OwnedFd, FromRawFd, AsRawFd, AsFd}; +/// # use std::time::{Instant, Duration}; +/// # fn main() -> nix::Result<()> { +/// const DATA: u64 = 17; +/// const MILLIS: u64 = 100; +/// +/// // Create epoll +/// let epoll = Epoll::new(EpollCreateFlags::empty())?; +/// +/// // Create eventfd & Add event +/// let eventfd = unsafe { OwnedFd::from_raw_fd(eventfd(0, EfdFlags::empty())?) }; +/// epoll.add(eventfd.as_fd(), EpollEvent::new(EpollFlags::EPOLLIN,DATA))?; +/// +/// // Arm eventfd & Time wait +/// write(eventfd.as_raw_fd(), &1u64.to_ne_bytes())?; +/// let now = Instant::now(); +/// +/// // Wait on event +/// let mut events = [EpollEvent::empty()]; +/// epoll.wait(&mut events, MILLIS as isize); +/// +/// // Assert data correct & timeout didn't occur +/// assert_eq!(events[0].data(), DATA); +/// assert!(now.elapsed() < Duration::from_millis(MILLIS)); +/// # Ok(()) +/// # } +/// ``` +#[derive(Debug)] +pub struct Epoll(pub OwnedFd); +impl Epoll { + /// Creates a new epoll instance and returns a file descriptor referring to that instance. + /// + /// [`epoll_create1`](https://man7.org/linux/man-pages/man2/epoll_create1.2.html). + pub fn new(flags: EpollCreateFlags) -> Result { + let res = unsafe { libc::epoll_create1(flags.bits()) }; + let fd = Errno::result(res)?; + let owned_fd = unsafe { OwnedFd::from_raw_fd(fd) }; + Ok(Self(owned_fd)) + } + /// Add an entry to the interest list of the epoll file descriptor for + /// specified in events. + /// + /// [`epoll_ctl`](https://man7.org/linux/man-pages/man2/epoll_ctl.2.html) with `EPOLL_CTL_ADD`. + pub fn add(&self, fd: Fd, mut event: EpollEvent) -> Result<()> { + self.epoll_ctl(EpollOp::EpollCtlAdd,fd.as_fd().as_raw_fd(),&mut event) + } + /// Remove (deregister) the target file descriptor `fd` from the interest list. + /// + /// [`epoll_ctl`](https://man7.org/linux/man-pages/man2/epoll_ctl.2.html) with `EPOLL_CTL_DEL` . + pub fn delete(&self, fd: Fd) -> Result<()> { + self.epoll_ctl(EpollOp::EpollCtlDel,fd.as_fd().as_raw_fd(),None) + } + /// Change the settings associated with `fd` in the interest list to the new settings specified + /// in `event`. + /// + /// [`epoll_ctl`](https://man7.org/linux/man-pages/man2/epoll_ctl.2.html) with `EPOLL_CTL_MOD`. + pub fn modify(&self,fd: Fd, event: &mut EpollEvent) -> Result<()> { + self.epoll_ctl(EpollOp::EpollCtlMod,fd.as_fd().as_raw_fd(),event) + } + /// Waits for I/O events, blocking the calling thread if no events are currently available. + /// (This can be thought of as fetching items from the ready list of the epoll instance.) + /// + /// [`epoll_wait`](https://man7.org/linux/man-pages/man2/epoll_wait.2.html) + pub fn wait(&self, events: &mut [EpollEvent], timeout: isize) -> Result { + let res = unsafe { + libc::epoll_wait( + self.0.as_raw_fd(), + events.as_mut_ptr() as *mut libc::epoll_event, + events.len() as c_int, + timeout as c_int, + ) + }; + + Errno::result(res).map(|r| r as usize) + } + /// This system call is used to add, modify, or remove entries in the interest list of the epoll + /// instance referred to by `self`. It requests that the operation `op` be performed for the + /// target file descriptor, `fd`. + /// + /// [`epoll_ctl`](https://man7.org/linux/man-pages/man2/epoll_ctl.2.html) + pub fn epoll_ctl<'a, T>( + &self, + op: EpollOp, + fd: RawFd, + event: T, + ) -> Result<()> + where + T: Into>, + { + let event: Option<&mut EpollEvent> = event.into(); + let ptr = event.map(|x|&mut x.event as *mut libc::epoll_event).unwrap_or(std::ptr::null_mut()); + unsafe { + Errno::result(libc::epoll_ctl(self.0.as_raw_fd(), op as c_int, fd, ptr)).map(drop) + } + } +} + #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] #[repr(i32)] #[non_exhaustive] @@ -68,61 +168,4 @@ impl EpollEvent { pub fn data(&self) -> u64 { self.event.u64 } -} - -#[inline] -pub fn epoll_create() -> Result { - let res = unsafe { libc::epoll_create(1024) }; - - Errno::result(res) -} - -#[inline] -pub fn epoll_create1(flags: EpollCreateFlags) -> Result { - let res = unsafe { libc::epoll_create1(flags.bits()) }; - - Errno::result(res) -} - -#[inline] -pub fn epoll_ctl<'a, T>( - epfd: RawFd, - op: EpollOp, - fd: RawFd, - event: T, -) -> Result<()> -where - T: Into>, -{ - let mut event: Option<&mut EpollEvent> = event.into(); - if event.is_none() && op != EpollOp::EpollCtlDel { - Err(Errno::EINVAL) - } else { - let res = unsafe { - if let Some(ref mut event) = event { - libc::epoll_ctl(epfd, op as c_int, fd, &mut event.event) - } else { - libc::epoll_ctl(epfd, op as c_int, fd, ptr::null_mut()) - } - }; - Errno::result(res).map(drop) - } -} - -#[inline] -pub fn epoll_wait( - epfd: RawFd, - events: &mut [EpollEvent], - timeout_ms: isize, -) -> Result { - let res = unsafe { - libc::epoll_wait( - epfd, - events.as_mut_ptr() as *mut libc::epoll_event, - events.len() as c_int, - timeout_ms as c_int, - ) - }; - - Errno::result(res).map(|r| r as usize) -} +} \ No newline at end of file diff --git a/test/sys/test_epoll.rs b/test/sys/test_epoll.rs index 915691595c..d48f01b642 100644 --- a/test/sys/test_epoll.rs +++ b/test/sys/test_epoll.rs @@ -1,24 +1,23 @@ use nix::errno::Errno; -use nix::sys::epoll::{epoll_create1, epoll_ctl}; -use nix::sys::epoll::{EpollCreateFlags, EpollEvent, EpollFlags, EpollOp}; +use nix::sys::epoll::{ + Epoll, EpollCreateFlags, EpollEvent, EpollFlags, EpollOp, +}; #[test] pub fn test_epoll_errno() { - let efd = epoll_create1(EpollCreateFlags::empty()).unwrap(); - let result = epoll_ctl(efd, EpollOp::EpollCtlDel, 1, None); - result.expect_err("assertion failed"); - assert_eq!(result.unwrap_err(), Errno::ENOENT); + let efd = Epoll::new(EpollCreateFlags::empty()).unwrap(); + let result = efd.epoll_ctl(EpollOp::EpollCtlDel, 1, None); + assert_eq!(result, Err(Errno::ENOENT)); - let result = epoll_ctl(efd, EpollOp::EpollCtlAdd, 1, None); - result.expect_err("assertion failed"); - assert_eq!(result.unwrap_err(), Errno::EINVAL); + let result = efd.epoll_ctl(EpollOp::EpollCtlAdd, 1, None); + assert_eq!(result, Err(Errno::EFAULT)); } #[test] pub fn test_epoll_ctl() { - let efd = epoll_create1(EpollCreateFlags::empty()).unwrap(); + let efd = Epoll::new(EpollCreateFlags::empty()).unwrap(); let mut event = EpollEvent::new(EpollFlags::EPOLLIN | EpollFlags::EPOLLERR, 1); - epoll_ctl(efd, EpollOp::EpollCtlAdd, 1, &mut event).unwrap(); - epoll_ctl(efd, EpollOp::EpollCtlDel, 1, None).unwrap(); + efd.epoll_ctl(EpollOp::EpollCtlAdd, 1, &mut event).unwrap(); + efd.epoll_ctl(EpollOp::EpollCtlDel, 1, None).unwrap(); }