1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370
//! Crate for handling signals with Mio. //! //! See the [`Signals`] documentation. //! //! ## Supported platforms //! //! Currently supported platforms: //! //! * Android //! * DragonFly BSD //! * FreeBSD //! * Linux //! * NetBSD //! * OpenBSD //! * iOS //! * macOS //! //! The most notable exception in the list is Windows. If you want to contribute //! a port to Windows please see [issue #4]. //! //! [issue #4]: https://github.com/Thomasdezeeuw/mio-signals/issues/4 // TODO: #[non_exhaustive] to `Signal`. #![warn( missing_debug_implementations, missing_docs, rust_2018_idioms, unused_qualifications, unused_results, variant_size_differences )] // Disallow warnings when running tests. #![cfg_attr(test, deny(warnings))] // Disallow warnings in examples, we want to set a good example after all. #![doc(test(attr(deny(warnings))))] // `SignalSet` can never be empty, thus an `is_empty` method doesn't make sense. #![allow(clippy::len_without_is_empty)] use std::iter::FusedIterator; use std::num::NonZeroU8; use std::ops::BitOr; use std::{fmt, io}; use mio::{event, Interest, Registry, Token}; mod sys; /// Notification of process signals. /// /// # Notes /// /// On Android and Linux this will block all signals in the signal set given /// when creating `Signals`, using [`sigprocmask(2)`]. This means that the /// program is not interrupted, or in any way notified of signal until the /// assiocated [`Poll`] is [polled]. /// /// On platforms that support [`kqueue(2)`] the signal handler action is set to /// `SIG_IGN` using [`sigaction(2)`], meaning that all signals will be ignored. /// Same as on Linux based systems; the program is not interrupted, or in any way /// notified of signal until the assiocated [`Poll`] is [polled]. /// /// [`sigprocmask(2)`]: http://man7.org/linux/man-pages/man2/sigprocmask.2.html /// [`Poll`]: mio::Poll /// [polled]: mio::Poll::poll /// [`kqueue(2)`]: https://www.freebsd.org/cgi/man.cgi?query=kqueue&sektion=2 /// [`sigaction(2)`]: https://www.freebsd.org/cgi/man.cgi?query=sigaction&sektion=2 /// /// # Implementation notes /// /// On platforms that support [`kqueue(2)`] this will use the `EVFILT_SIGNAL` /// event filter. On Android and Linux it uses [`signalfd(2)`]. /// /// [`signalfd(2)`]: http://man7.org/linux/man-pages/man2/signalfd.2.html /// /// # Examples /// ``` /// use std::io; /// /// use mio::{Poll, Events, Interest, Token}; /// use mio_signals::{Signals, Signal, SignalSet}; /// /// const SIGNAL: Token = Token(10); /// /// fn main() -> io::Result<()> { /// let mut poll = Poll::new()?; /// let mut events = Events::with_capacity(128); /// /// // Create a `Signals` instance that will catch signals for us. /// let mut signals = Signals::new(SignalSet::all())?; /// // And register it with our `Poll` instance. /// poll.registry().register(&mut signals, SIGNAL, Interest::READABLE)?; /// /// # // Don't want to let the example run for ever. /// # let awakener = mio::Waker::new(&poll.registry(), Token(20))?; /// # awakener.wake()?; /// # /// loop { /// poll.poll(&mut events, None)?; /// /// for event in events.iter() { /// match event.token() { /// // Because we're using edge triggers (default in Mio) we need /// // to keep calling `receive` until it returns `Ok(None)`. /// SIGNAL => loop { /// match signals.receive()? { /// Some(Signal::Interrupt) => println!("Got interrupt signal"), /// Some(Signal::Terminate) => println!("Got terminate signal"), /// Some(Signal::Quit) => println!("Got quit signal"), /// None => break, /// } /// }, /// # Token(20) => return Ok(()), /// _ => println!("Got unexpected event: {:?}", event), /// } /// } /// } /// } /// ``` #[derive(Debug)] pub struct Signals { sys: sys::Signals, } impl Signals { /// Create a new signal notifier. pub fn new(signals: SignalSet) -> io::Result<Signals> { sys::Signals::new(signals).map(|sys| Signals { sys }) } /// Receive a signal, if any. /// /// If no signal is available this returns `Ok(None)`. pub fn receive(&mut self) -> io::Result<Option<Signal>> { self.sys.receive() } } impl event::Source for Signals { fn register( &mut self, registry: &Registry, token: Token, interests: Interest, ) -> io::Result<()> { self.sys.register(registry, token, interests) } fn reregister( &mut self, registry: &Registry, token: Token, interests: Interest, ) -> io::Result<()> { self.sys.reregister(registry, token, interests) } fn deregister(&mut self, registry: &Registry) -> io::Result<()> { self.sys.deregister(registry) } } /// Set of [`Signal`]s used in registering signal notifications with [`Signals`]. /// /// # Examples /// /// ``` /// use mio_signals::{Signal, SignalSet}; /// /// // Signal set can be created by bit-oring (`|`) signals together. /// let set: SignalSet = Signal::Interrupt | Signal::Quit; /// assert_eq!(set.len(), 2); /// /// assert!(set.contains(Signal::Interrupt)); /// assert!(set.contains(Signal::Quit)); /// assert!(!set.contains(Signal::Terminate)); /// assert!(set.contains(Signal::Interrupt | Signal::Quit)); /// ``` #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)] pub struct SignalSet(NonZeroU8); // NOTE: these may never be zero. const INTERRUPT: u8 = 1; const QUIT: u8 = 1 << 1; const TERMINATE: u8 = 1 << 2; impl SignalSet { /// Create a new set with all signals. pub const fn all() -> SignalSet { SignalSet(unsafe { NonZeroU8::new_unchecked(INTERRUPT | QUIT | TERMINATE) }) } /// Number of signals in the set. pub const fn len(self) -> usize { self.0.get().count_ones() as usize } /// Whether or not all signals in `other` are contained within `self`. /// /// # Notes /// /// This can also be used with [`Signal`]. /// /// # Examples /// /// ``` /// use mio_signals::{Signal, SignalSet}; /// /// let set = SignalSet::all(); /// /// assert!(set.contains(Signal::Interrupt)); /// assert!(set.contains(Signal::Quit)); /// assert!(set.contains(Signal::Interrupt | Signal::Quit)); /// ``` pub fn contains<S>(self, other: S) -> bool where S: Into<SignalSet>, { let other = other.into(); (self.0.get() & other.0.get()) == other.0.get() } } impl From<Signal> for SignalSet { fn from(signal: Signal) -> Self { SignalSet(unsafe { NonZeroU8::new_unchecked(match signal { Signal::Interrupt => INTERRUPT, Signal::Quit => QUIT, Signal::Terminate => TERMINATE, }) }) } } impl BitOr for SignalSet { type Output = SignalSet; fn bitor(self, rhs: Self) -> Self { SignalSet(unsafe { NonZeroU8::new_unchecked(self.0.get() | rhs.0.get()) }) } } impl BitOr<Signal> for SignalSet { type Output = SignalSet; fn bitor(self, rhs: Signal) -> Self { self | Into::<SignalSet>::into(rhs) } } impl IntoIterator for SignalSet { type Item = Signal; type IntoIter = SignalSetIter; fn into_iter(self) -> Self::IntoIter { SignalSetIter(self.0.get()) } } impl fmt::Debug for SignalSet { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { self.into_iter().fmt(f) } } /// Iterator implementation for [`SignalSet`]. /// /// # Notes /// /// The order in which the signals are iterated over is undefined. pub struct SignalSetIter(u8); impl Iterator for SignalSetIter { type Item = Signal; fn next(&mut self) -> Option<Self::Item> { let n = self.0.trailing_zeros(); match n { 0 => Some(Signal::Interrupt), 1 => Some(Signal::Quit), 2 => Some(Signal::Terminate), _ => None, } .map(|signal| { // Remove the signal from the set. self.0 &= !(1 << n); signal }) } fn size_hint(&self) -> (usize, Option<usize>) { let size = self.len(); (size, Some(size)) } fn count(self) -> usize { self.len() } } impl ExactSizeIterator for SignalSetIter { fn len(&self) -> usize { self.0.count_ones() as usize } } impl FusedIterator for SignalSetIter {} impl fmt::Debug for SignalSetIter { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { let mut set = SignalSetIter(self.0); if set.len() == 0 { f.write_str("(empty)") } else { let first = set.next().unwrap(); first.fmt(f)?; for signal in set { f.write_str("|")?; signal.fmt(f)?; } Ok(()) } } } /// Signal returned by [`Signals`]. #[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)] pub enum Signal { /// Interrupt signal. /// /// This signal is received by the process when its controlling terminal /// wishes to interrupt the process. This signal will for example be send /// when Ctrl+C is pressed in most terminals. /// /// Corresponds to POSIX signal `SIGINT`. Interrupt, /// Termination request signal. /// /// This signal received when the process is requested to terminate. This /// allows the process to perform nice termination, releasing resources and /// saving state if appropriate. This signal will be send when using the /// `kill` command for example. /// /// Corresponds to POSIX signal `SIGTERM`. Terminate, /// Terminal quit signal. /// /// This signal is received when the process is requested to quit and /// perform a core dump. /// /// Corresponds to POSIX signal `SIGQUIT`. Quit, } impl BitOr for Signal { type Output = SignalSet; fn bitor(self, rhs: Self) -> SignalSet { Into::<SignalSet>::into(self) | rhs } } impl BitOr<SignalSet> for Signal { type Output = SignalSet; fn bitor(self, rhs: SignalSet) -> SignalSet { rhs | self } }