From 511ed2673095e1a1bbab067ba834e518bb546cef Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Mon, 10 Jul 2023 22:39:42 +0200
Subject: [PATCH] Interest as usize
---
tokio/src/io/interest.rs | 233 +++++++++++++++++++++++++--------------
1 file changed, 151 insertions(+), 82 deletions(-)
diff --git a/tokio/src/io/interest.rs b/tokio/src/io/interest.rs
index b7659c076a5..c6de37b886e 100644
--- a/tokio/src/io/interest.rs
+++ b/tokio/src/io/interest.rs
@@ -5,65 +5,70 @@ use crate::io::ready::Ready;
use std::fmt;
use std::ops;
+// These must be unique.
+// same as mio
+const READABLE: usize = 0b0001;
+const WRITABLE: usize = 0b0010;
+// The following are not available on all platforms.
+#[cfg(target_os = "freebsd")]
+const AIO: usize = 0b0100;
+#[cfg(target_os = "freebsd")]
+const LIO: usize = 0b1000;
+#[cfg(any(target_os = "linux", target_os = "android"))]
+const PRIORITY: usize = 0b0001_0000;
+// error is available on all platforms, but behavior is platform-specific
+// mio does not have this interest
+const ERROR: usize = 0b0010_0000;
+
/// Readiness event interest.
///
/// Specifies the readiness events the caller is interested in when awaiting on
/// I/O resource readiness states.
#[cfg_attr(docsrs, doc(cfg(feature = "net")))]
#[derive(Clone, Copy, Eq, PartialEq)]
-pub struct Interest {
- mio: Option<mio::Interest>,
- has_error_interest: bool,
-}
+pub struct Interest(usize);
impl Interest {
- const fn new(mio: mio::Interest) -> Self {
- Self {
- mio: Some(mio),
- has_error_interest: false,
- }
- }
-
// The non-FreeBSD definitions in this block are active only when
// building documentation.
cfg_aio! {
/// Interest for POSIX AIO.
#[cfg(target_os = "freebsd")]
- pub const AIO: Interest = Interest::new(mio::Interest::AIO);
+ pub const AIO: Interest = Interest(AIO);
/// Interest for POSIX AIO.
#[cfg(not(target_os = "freebsd"))]
- pub const AIO: Interest = Interest::new(mio::Interest::READABLE);
+ pub const AIO: Interest = Interest(READABLE);
/// Interest for POSIX AIO lio_listio events.
#[cfg(target_os = "freebsd")]
- pub const LIO: Interest = Interest::new(mio::Interest::LIO);
+ pub const LIO: Interest = Interest(LIO);
/// Interest for POSIX AIO lio_listio events.
#[cfg(not(target_os = "freebsd"))]
- pub const LIO: Interest = Interest::new(mio::Interest::READABLE);
+ pub const LIO: Interest = Interest(READABLE);
}
/// Interest in all readable events.
///
/// Readable interest includes read-closed events.
- pub const READABLE: Interest = Interest::new(mio::Interest::READABLE);
+ pub const READABLE: Interest = Interest(READABLE);
/// Interest in all writable events.
///
/// Writable interest includes write-closed events.
- pub const WRITABLE: Interest = Interest::new(mio::Interest::WRITABLE);
+ pub const WRITABLE: Interest = Interest(WRITABLE);
/// Interest in error events.
- pub const ERROR: Interest = Interest {
- mio: None,
- has_error_interest: true,
- };
+ ///
+ /// Passes error interest to the underlying OS selector.
+ /// Behavior is platform-specific, read your platform's documentation.
+ pub const ERROR: Interest = Interest(ERROR);
/// Returns a `Interest` set representing priority completion interests.
#[cfg(any(target_os = "linux", target_os = "android"))]
#[cfg_attr(docsrs, doc(cfg(any(target_os = "linux", target_os = "android"))))]
- pub const PRIORITY: Interest = Interest::new(mio::Interest::PRIORITY);
+ pub const PRIORITY: Interest = Interest(PRIORITY);
/// Returns true if the value includes readable interest.
///
@@ -79,10 +84,7 @@ impl Interest {
/// assert!(both.is_readable());
/// ```
pub const fn is_readable(self) -> bool {
- match self.mio {
- Some(mio) => mio.is_readable(),
- None => false,
- }
+ self.0 & READABLE != 0
}
/// Returns true if the value includes writable interest.
@@ -99,10 +101,34 @@ impl Interest {
/// assert!(both.is_writable());
/// ```
pub const fn is_writable(self) -> bool {
- match self.mio {
- Some(mio) => mio.is_writable(),
- None => false,
- }
+ self.0 & WRITABLE != 0
+ }
+
+ /// Returns true if the value includes error interest.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use tokio::io::Interest;
+ ///
+ /// assert!(Interest::ERROR.is_error());
+ /// assert!(!Interest::WRITABLE.is_error());
+ ///
+ /// let combined = Interest::READABLE | Interest::ERROR;
+ /// assert!(combined.is_error());
+ /// ```
+ pub const fn is_error(self) -> bool {
+ self.0 & ERROR != 0
+ }
+
+ #[cfg(target_os = "freebsd")]
+ const fn is_aio(self) -> bool {
+ self.0 & AIO != 0
+ }
+
+ #[cfg(target_os = "freebsd")]
+ const fn is_lio(self) -> bool {
+ self.0 & LIO != 0
}
/// Returns true if the value includes priority interest.
@@ -121,10 +147,7 @@ impl Interest {
#[cfg(any(target_os = "linux", target_os = "android"))]
#[cfg_attr(docsrs, doc(cfg(any(target_os = "linux", target_os = "android"))))]
pub const fn is_priority(self) -> bool {
- match self.mio {
- Some(mio) => mio.is_priority(),
- None => false,
- }
+ self.0 & PRIORITY != 0
}
/// Add together two `Interest` values.
@@ -141,44 +164,51 @@ impl Interest {
/// assert!(BOTH.is_readable());
/// assert!(BOTH.is_writable());
pub const fn add(self, other: Interest) -> Interest {
- Interest {
- mio: match (self.mio, other.mio) {
- (Some(a), Some(b)) => Some(a.add(b)),
- (Some(c), None) | (None, Some(c)) => Some(c),
- (None, None) => None,
- },
- has_error_interest: self.has_error_interest || other.has_error_interest,
- }
- }
-
- /// Returns true if the value includes error interest.
- ///
- /// # Examples
- ///
- /// ```
- /// use tokio::io::Interest;
- ///
- /// assert!(Interest::ERROR.is_error());
- /// assert!(!Interest::WRITABLE.is_error());
- ///
- /// let combined = Interest::READABLE | Interest::ERROR;
- /// assert!(combined.is_error());
- /// ```
- pub const fn is_error(self) -> bool {
- self.has_error_interest
+ Self(self.0 | other.0)
}
// This function must be crate-private to avoid exposing a `mio` dependency.
- pub(crate) const fn to_mio(self) -> mio::Interest {
- match self.mio {
- Some(mio) => mio,
- None => {
- // error interest is implicit, and mio does not have a specific Interest::ERROR
- // so we provide an arbitrary interest here, and filter out the this readiness
- // in `Interest::mask` and `Ready::from_interest`.
- mio::Interest::READABLE
- }
+ pub(crate) fn to_mio(self) -> mio::Interest {
+ // mio does not allow and empty interest, so pick an arbitrary starting value
+ let mut mio = mio::Interest::READABLE;
+
+ if self.is_readable() {
+ mio |= mio::Interest::READABLE;
+ }
+
+ if self.is_writable() {
+ mio |= mio::Interest::WRITABLE;
+ }
+
+ #[cfg(any(target_os = "linux", target_os = "android"))]
+ if self.is_priority() {
+ mio |= mio::Interest::PRIORITY;
+ }
+
+ #[cfg(target_os = "freebsd")]
+ if self.is_aio() {
+ mio |= mio::Interest::AIO;
+ }
+
+ #[cfg(target_os = "freebsd")]
+ if self.is_lio() {
+ mio |= mio::Interest::LIO;
+ }
+
+ // Finally remove the starting value unless either:
+ //
+ // - the readable interest is specified
+ // - the error interest is specified. There is no error interest in mio, because error
+ // events are always reported. But mio interests cannot be empty and one is needed
+ // just for the registeration.
+ //
+ // read readiness is filtered out in `Interest::mask` or `Ready::from_interest` if
+ // needed
+ if !self.is_readable() && !self.is_error() {
+ mio.remove(mio::Interest::READABLE);
}
+
+ mio
}
pub(crate) fn mask(self) -> Ready {
@@ -211,22 +241,61 @@ impl ops::BitOrAssign for Interest {
impl fmt::Debug for Interest {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
- match self.mio {
- None => {
- if self.has_error_interest {
- write!(fmt, "ERROR")
- } else {
- Ok(())
- }
+ let mut separator = false;
+
+ if self.is_readable() {
+ if separator {
+ write!(fmt, " | ")?;
+ }
+ write!(fmt, "READABLE")?;
+ separator = true;
+ }
+
+ if self.is_writable() {
+ if separator {
+ write!(fmt, " | ")?;
+ }
+ write!(fmt, "WRITABLE")?;
+ separator = true;
+ }
+
+ #[cfg(any(target_os = "linux", target_os = "android"))]
+ if self.is_priority() {
+ if separator {
+ write!(fmt, " | ")?;
+ }
+ write!(fmt, "PRIORITY")?;
+ separator = true;
+ }
+
+ #[cfg(target_os = "freebsd")]
+ if self.is_aio() {
+ if separator {
+ write!(fmt, " | ")?;
+ }
+ write!(fmt, "AIO")?;
+ separator = true;
+ }
+
+ #[cfg(target_os = "freebsd")]
+ if self.is_lio() {
+ if separator {
+ write!(fmt, " | ")?;
}
- Some(mio) => {
- mio.fmt(fmt)?;
- if self.has_error_interest {
- write!(fmt, " | ERROR")
- } else {
- Ok(())
- }
+ write!(fmt, "LIO")?;
+ separator = true;
+ }
+
+ if self.is_error() {
+ if separator {
+ write!(fmt, " | ")?;
}
+ write!(fmt, "ERROR")?;
+ separator = true;
}
+
+ let _ = separator;
+
+ Ok(())
}
}