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Stjepan Glavina 2020-08-06 15:02:59 +02:00
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github: stjepang

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name: Build and test
on:
push:
branches:
- master
pull_request:
jobs:
build_and_test:
runs-on: ${{ matrix.os }}
strategy:
fail-fast: false
matrix:
os: [ubuntu-latest, windows-latest, macos-latest]
rust: [nightly, beta, stable, 1.39.0]
steps:
- uses: actions/checkout@v2
- name: Set current week of the year in environnement
if: startsWith(matrix.os, 'ubuntu') || startsWith(matrix.os, 'macOS')
run: echo "::set-env name=CURRENT_WEEK::$(date +%V)"
- name: Set current week of the year in environnement
if: startsWith(matrix.os, 'windows')
run: echo "::set-env name=CURRENT_WEEK::$(Get-Date -UFormat %V)"
- name: Install latest ${{ matrix.rust }}
uses: actions-rs/toolchain@v1
with:
toolchain: ${{ matrix.rust }}
profile: minimal
override: true
- name: Run basic cargo check
uses: actions-rs/cargo@v1
with:
command: check
args: --all --bins --all-features
- name: Run cargo check
if: startsWith(matrix.rust, '1.39.0') == false
uses: actions-rs/cargo@v1
with:
command: check
args: --all --benches --bins --examples --tests --all-features
- name: Run cargo check (without dev-dependencies to catch missing feature flags)
if: startsWith(matrix.rust, 'nightly')
uses: actions-rs/cargo@v1
with:
command: check
args: -Z features=dev_dep
- name: Run cargo test
if: startsWith(matrix.rust, '1.39.0') == false
uses: actions-rs/cargo@v1
with:
command: test

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name: Cross compile
on:
push:
branches:
- master
pull_request:
jobs:
cross:
name: Cross compile
runs-on: ${{ matrix.os }}
strategy:
matrix:
os: [ubuntu-latest, macos-latest]
steps:
- uses: actions/checkout@master
- name: Install nightly
uses: actions-rs/toolchain@v1
with:
toolchain: nightly
override: true
- name: Install docker
if: startsWith(matrix.os, 'ubuntu')
run: sudo apt install docker
- name: Install cross
run: cargo install cross
- name: Android
if: startsWith(matrix.os, 'ubuntu')
run: cross test --target arm-linux-androideabi
- name: NetBSD
if: startsWith(matrix.os, 'ubuntu')
run: cross build --target x86_64-unknown-netbsd
- name: FreeBSD
if: startsWith(matrix.os, 'ubuntu')
run: cross build --target x86_64-unknown-freebsd
- name: iOS
if: startsWith(matrix.os, 'macos')
run: cross build --target aarch64-apple-ios
# - name: illumos
# if: startsWith(matrix.os, 'ubuntu')
# run: cross build --target x86_64-unknown-illumos

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name: Lint
on:
push:
branches:
- master
pull_request:
jobs:
clippy:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set current week of the year in environnement
run: echo "::set-env name=CURRENT_WEEK::$(date +%V)"
- uses: actions-rs/toolchain@v1
with:
toolchain: stable
profile: minimal
components: clippy
- uses: actions-rs/clippy-check@v1
with:
token: ${{ secrets.GITHUB_TOKEN }}
args: --all-features -- -W clippy::all

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name: Security audit
on:
push:
branches:
- master
pull_request:
jobs:
security_audit:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set current week of the year in environnement
run: echo "::set-env name=CURRENT_WEEK::$(date +%V)"
- uses: actions-rs/audit-check@v1
with:
token: ${{ secrets.GITHUB_TOKEN }}

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/target
Cargo.lock

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# Version 0.1.0
- Initial version

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[package]
name = "polling"
version = "0.1.0"
authors = ["Stjepan Glavina <stjepang@gmail.com>"]
edition = "2018"
description = "Portable interface to epoll, kqueue, and wepoll"
license = "Apache-2.0 OR MIT"
repository = "https://github.com/stjepang/polling"
homepage = "https://github.com/stjepang/polling"
documentation = "https://docs.rs/polling"
keywords = ["mio", "epoll", "kqueue", "iocp", "wepoll"]
categories = ["asynchronous", "network-programming", "os"]
readme = "README.md"
[dependencies]
cfg-if = "0.1.10"
libc = "0.2.74"
[target.'cfg(windows)'.dependencies]
# Patched version of wepoll that can be notified by PostQueuedCompletionStatus.
wepoll-sys-stjepang = "1.0.6"
winapi = { version = "0.3.9", features = ["ioapiset"] }

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# polling
[![Build](https://github.com/stjepang/polling/workflows/Build%20and%20test/badge.svg)](
https://github.com/stjepang/polling/actions)
[![License](https://img.shields.io/badge/license-MIT%2FApache--2.0-blue.svg)](
https://github.com/stjepang/polling)
[![Cargo](https://img.shields.io/crates/v/polling.svg)](
https://crates.io/crates/polling)
[![Documentation](https://docs.rs/polling/badge.svg)](
https://docs.rs/polling)
Portable interface to epoll, kqueue, and wepoll.
Supported platforms:
- [epoll](https://en.wikipedia.org/wiki/Epoll): Linux, Android, illumos
- [kqueue](https://en.wikipedia.org/wiki/Kqueue): macOS, iOS, FreeBSD, NetBSD, OpenBSD,
DragonFly BSD
- [wepoll](https://github.com/piscisaureus/wepoll): Windows
Polling is done in oneshot mode, which means interest in I/O events needs to be reset after
an event is delivered if we're interested in the next event of the same kind.
Only one thread can be waiting for I/O events at a time.
## Examples
```rust
use polling::{Event, Poller};
use std::net::TcpListener;
// Create a TCP listener and put the socket in non-blocking mode.
let socket = TcpListener::bind("127.0.0.1:8000")?;
socket.set_nonblocking(true)?;
let key = 7; // arbitrary key identifying the socket
// Create a poller and register interest in readability on the socket.
let poller = Poller::new()?;
poller.insert(&socket)?;
poller.interest(&socket, Event::readable(key))?;
// The event loop.
let mut events = Vec::new();
loop {
// Wait for at least one I/O event.
events.clear();
poller.wait(&mut events, None)?;
for ev in &events {
if ev.key == key {
// Perform a non-blocking accept operation.
socket.accept()?;
// Set interest in the next readability event.
poller.interest(&socket, Event::readable(key))?;
}
}
}
```
## License
Licensed under either of
* Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
at your option.
#### Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
dual licensed as above, without any additional terms or conditions.

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use std::io;
use std::net::TcpListener;
use polling::{Event, Poller};
fn main() -> io::Result<()> {
let l1 = TcpListener::bind("127.0.0.1:8001")?;
l1.set_nonblocking(true)?;
let l2 = TcpListener::bind("127.0.0.1:8002")?;
l2.set_nonblocking(true)?;
let poller = Poller::new()?;
poller.insert(&l1)?;
poller.insert(&l2)?;
poller.interest(&l1, Event::readable(1))?;
poller.interest(&l2, Event::readable(2))?;
let mut events = Vec::new();
loop {
events.clear();
poller.wait(&mut events, None)?;
for ev in &events {
match ev.key {
1 => {
println!("Accept on l1");
l1.accept()?;
poller.interest(&l1, Event::readable(1))?;
}
2 => {
println!("Accept on l2");
l2.accept()?;
poller.interest(&l2, Event::readable(2))?;
}
_ => unreachable!(),
}
}
}
}

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//! Bindings to epoll (Linux, Android, illumos).
use std::convert::TryInto;
use std::io;
use std::os::unix::io::RawFd;
use std::ptr;
use std::time::Duration;
use std::usize;
use crate::Event;
/// Interface to epoll.
#[derive(Debug)]
pub struct Poller {
/// File descriptor for the epoll instance.
epoll_fd: RawFd,
/// File descriptor for the eventfd that produces notifications.
event_fd: RawFd,
}
impl Poller {
/// Creates a new poller.
pub fn new() -> io::Result<Poller> {
// According to libuv, `EPOLL_CLOEXEC` is not defined on Android API < 21.
// But `EPOLL_CLOEXEC` is an alias for `O_CLOEXEC` on that platform, so we use it instead.
#[cfg(target_os = "android")]
const CLOEXEC: libc::c_int = libc::O_CLOEXEC;
#[cfg(not(target_os = "android"))]
const CLOEXEC: libc::c_int = libc::EPOLL_CLOEXEC;
// Create an epoll instance.
let epoll_fd = unsafe {
// Check if the `epoll_create1` symbol is available on this platform.
let ptr = libc::dlsym(
libc::RTLD_DEFAULT,
"epoll_create1\0".as_ptr() as *const libc::c_char,
);
if ptr.is_null() {
// If not, use `epoll_create` and manually set `CLOEXEC`.
let fd = match libc::epoll_create(1024) {
-1 => return Err(io::Error::last_os_error()),
fd => fd,
};
let flags = libc::fcntl(fd, libc::F_GETFD);
libc::fcntl(fd, libc::F_SETFD, flags | libc::FD_CLOEXEC);
fd
} else {
// Use `epoll_create1` with `CLOEXEC`.
let epoll_create1 = std::mem::transmute::<
*mut libc::c_void,
unsafe extern "C" fn(libc::c_int) -> libc::c_int,
>(ptr);
match epoll_create1(CLOEXEC) {
-1 => return Err(io::Error::last_os_error()),
fd => fd,
}
}
};
// Set up eventfd.
let event_fd = syscall!(eventfd(0, libc::EFD_CLOEXEC | libc::EFD_NONBLOCK))?;
let poller = Poller { epoll_fd, event_fd };
poller.insert(event_fd)?;
poller.interest(event_fd, NOTIFY_KEY, true, false)?;
Ok(poller)
}
/// Inserts a file descriptor.
pub fn insert(&self, fd: RawFd) -> io::Result<()> {
// Put the file descriptor in non-blocking mode.
let flags = syscall!(fcntl(fd, libc::F_GETFL))?;
syscall!(fcntl(fd, libc::F_SETFL, flags | libc::O_NONBLOCK))?;
// Register the file descriptor in epoll.
let mut ev = libc::epoll_event {
events: 0,
u64: 0u64,
};
syscall!(epoll_ctl(self.epoll_fd, libc::EPOLL_CTL_ADD, fd, &mut ev))?;
Ok(())
}
/// Sets interest in a read/write event on a file descriptor and associates a key with it.
pub fn interest(&self, fd: RawFd, key: usize, read: bool, write: bool) -> io::Result<()> {
let mut flags = libc::EPOLLONESHOT;
if read {
flags |= read_flags();
}
if write {
flags |= write_flags();
}
let mut ev = libc::epoll_event {
events: flags as _,
u64: key as u64,
};
syscall!(epoll_ctl(self.epoll_fd, libc::EPOLL_CTL_MOD, fd, &mut ev))?;
Ok(())
}
/// Removes a file descriptor.
pub fn remove(&self, fd: RawFd) -> io::Result<()> {
syscall!(epoll_ctl(
self.epoll_fd,
libc::EPOLL_CTL_DEL,
fd,
ptr::null_mut()
))?;
Ok(())
}
/// Waits for I/O events with an optional timeout.
///
/// Returns the number of processed I/O events.
///
/// If a notification occurs, the notification event will be included in the `events` list
/// identifiable by key `usize::MAX`.
pub fn wait(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<usize> {
// Convert the timeout to milliseconds.
let timeout_ms = timeout
.map(|t| {
if t == Duration::from_millis(0) {
t
} else {
// Non-zero duration must be at least 1ms.
t.max(Duration::from_millis(1))
}
})
.and_then(|t| t.as_millis().try_into().ok())
.unwrap_or(-1);
// Wait for I/O events.
let res = syscall!(epoll_wait(
self.epoll_fd,
events.list.as_mut_ptr() as *mut libc::epoll_event,
events.list.len() as libc::c_int,
timeout_ms as libc::c_int,
))?;
events.len = res as usize;
// Clear the notification (if received) and re-register interest in it.
let mut buf = [0u8; 8];
let _ = syscall!(read(
self.event_fd,
&mut buf[0] as *mut u8 as *mut libc::c_void,
buf.len()
));
self.interest(self.event_fd, NOTIFY_KEY, true, false)?;
Ok(events.len)
}
/// Sends a notification to wake up the current or next `wait()` call.
pub fn notify(&self) -> io::Result<()> {
let buf: [u8; 8] = 1u64.to_ne_bytes();
let _ = syscall!(write(
self.event_fd,
&buf[0] as *const u8 as *const libc::c_void,
buf.len()
));
Ok(())
}
}
impl Drop for Poller {
fn drop(&mut self) {
let _ = self.remove(self.event_fd);
let _ = syscall!(close(self.event_fd));
let _ = syscall!(close(self.epoll_fd));
}
}
/// Key associated with the eventfd for producing notifications.
const NOTIFY_KEY: usize = usize::MAX;
/// Epoll flags for all possible readability events.
fn read_flags() -> libc::c_int {
libc::EPOLLIN | libc::EPOLLRDHUP | libc::EPOLLHUP | libc::EPOLLERR | libc::EPOLLPRI
}
/// Epoll flags for all possible writability events.
fn write_flags() -> libc::c_int {
libc::EPOLLOUT | libc::EPOLLHUP | libc::EPOLLERR
}
/// A list of reported I/O events.
pub struct Events {
list: Box<[libc::epoll_event]>,
len: usize,
}
unsafe impl Send for Events {}
impl Events {
/// Creates an empty list.
pub fn new() -> Events {
let ev = libc::epoll_event { events: 0, u64: 0 };
let list = vec![ev; 1000].into_boxed_slice();
let len = 0;
Events { list, len }
}
/// Iterates over I/O events.
pub fn iter(&self) -> impl Iterator<Item = Event> + '_ {
self.list[..self.len].iter().map(|ev| Event {
key: ev.u64 as usize,
readable: (ev.events as libc::c_int & read_flags()) != 0,
writable: (ev.events as libc::c_int & write_flags()) != 0,
})
}
}

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//! Bindings to kqueue (macOS, iOS, FreeBSD, NetBSD, OpenBSD, DragonFly BSD).
use std::io::{self, Read, Write};
use std::os::unix::io::{AsRawFd, RawFd};
use std::os::unix::net::UnixStream;
use std::ptr;
use std::time::Duration;
use std::usize;
use crate::Event;
/// Interface to kqueue.
#[derive(Debug)]
pub struct Poller {
/// File descriptor for the kqueue instance.
kqueue_fd: RawFd,
/// Read side of a pipe for consuming notifications.
read_stream: UnixStream,
/// Write side of a pipe for producing notifications.
write_stream: UnixStream,
}
impl Poller {
/// Creates a new poller.
pub fn new() -> io::Result<Poller> {
// Create a kqueue instance.
let kqueue_fd = syscall!(kqueue())?;
syscall!(fcntl(kqueue_fd, libc::F_SETFD, libc::FD_CLOEXEC))?;
// Set up the notification pipe.
let (read_stream, write_stream) = UnixStream::pair()?;
read_stream.set_nonblocking(true)?;
write_stream.set_nonblocking(true)?;
let poller = Poller {
kqueue_fd,
read_stream,
write_stream,
};
poller.interest(
poller.read_stream.as_raw_fd(),
Event {
key: NOTIFY_KEY,
readable: true,
writable: false,
},
)?;
Ok(poller)
}
/// Inserts a file descriptor.
pub fn insert(&self, fd: RawFd) -> io::Result<()> {
// Put the file descriptor in non-blocking mode.
let flags = syscall!(fcntl(fd, libc::F_GETFL))?;
syscall!(fcntl(fd, libc::F_SETFL, flags | libc::O_NONBLOCK))?;
Ok(())
}
/// Sets interest in a read/write event on a file descriptor and associates a key with it.
pub fn interest(&self, fd: RawFd, ev: Event) -> io::Result<()> {
let mut read_flags = libc::EV_ONESHOT | libc::EV_RECEIPT;
let mut write_flags = libc::EV_ONESHOT | libc::EV_RECEIPT;
if ev.readable {
read_flags |= libc::EV_ADD;
} else {
read_flags |= libc::EV_DELETE;
}
if ev.writable {
write_flags |= libc::EV_ADD;
} else {
write_flags |= libc::EV_DELETE;
}
// A list of changes for kqueue.
let changelist = [
libc::kevent {
ident: fd as _,
filter: libc::EVFILT_READ,
flags: read_flags,
fflags: 0,
data: 0,
udata: ev.key as _,
},
libc::kevent {
ident: fd as _,
filter: libc::EVFILT_WRITE,
flags: write_flags,
fflags: 0,
data: 0,
udata: ev.key as _,
},
];
// Apply changes.
let mut eventlist = changelist;
syscall!(kevent(
self.kqueue_fd,
changelist.as_ptr() as *const libc::kevent,
changelist.len() as _,
eventlist.as_mut_ptr() as *mut libc::kevent,
eventlist.len() as _,
ptr::null(),
))?;
// Check for errors.
for ev in &eventlist {
// Explanation for ignoring EPIPE: https://github.com/tokio-rs/mio/issues/582
if (ev.flags & libc::EV_ERROR) != 0
&& ev.data != 0
&& ev.data != libc::ENOENT as _
&& ev.data != libc::EPIPE as _
{
return Err(io::Error::from_raw_os_error(ev.data as _));
}
}
Ok(())
}
/// Removes a file descriptor.
pub fn remove(&self, fd: RawFd) -> io::Result<()> {
// A list of changes for kqueue.
let changelist = [
libc::kevent {
ident: fd as _,
filter: libc::EVFILT_READ,
flags: libc::EV_DELETE | libc::EV_RECEIPT,
fflags: 0,
data: 0,
udata: 0 as _,
},
libc::kevent {
ident: fd as _,
filter: libc::EVFILT_WRITE,
flags: libc::EV_DELETE | libc::EV_RECEIPT,
fflags: 0,
data: 0,
udata: 0 as _,
},
];
// Apply changes.
let mut eventlist = changelist;
syscall!(kevent(
self.kqueue_fd,
changelist.as_ptr() as *const libc::kevent,
changelist.len() as _,
eventlist.as_mut_ptr() as *mut libc::kevent,
eventlist.len() as _,
ptr::null(),
))?;
// Check for errors.
for ev in &eventlist {
if (ev.flags & libc::EV_ERROR) != 0 && ev.data != 0 && ev.data != libc::ENOENT as _ {
return Err(io::Error::from_raw_os_error(ev.data as _));
}
}
Ok(())
}
/// Waits for I/O events with an optional timeout.
///
/// Returns the number of processed I/O events.
///
/// If a notification occurs, the notification event will be included in the `events` list
/// identifiable by key `usize::MAX`.
pub fn wait(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<usize> {
// Convert the `Duration` to `libc::timespec`.
let timeout = timeout.map(|t| libc::timespec {
tv_sec: t.as_secs() as libc::time_t,
tv_nsec: t.subsec_nanos() as libc::c_long,
});
// Wait for I/O events.
let changelist = [];
let eventlist = &mut events.list;
let res = syscall!(kevent(
self.kqueue_fd,
changelist.as_ptr() as *const libc::kevent,
changelist.len() as _,
eventlist.as_mut_ptr() as *mut libc::kevent,
eventlist.len() as _,
match &timeout {
None => ptr::null(),
Some(t) => t,
}
))?;
events.len = res as usize;
// Clear the notification (if received) and re-register interest in it.
while (&self.read_stream).read(&mut [0; 64]).is_ok() {}
self.interest(
self.read_stream.as_raw_fd(),
Event {
key: NOTIFY_KEY,
readable: true,
writable: false,
},
)?;
Ok(events.len)
}
/// Sends a notification to wake up the current or next `wait()` call.
pub fn notify(&self) -> io::Result<()> {
let _ = (&self.write_stream).write(&[1]);
Ok(())
}
}
impl Drop for Poller {
fn drop(&mut self) {
let _ = self.remove(self.read_stream.as_raw_fd());
let _ = syscall!(close(self.kqueue_fd));
}
}
/// Key associated with the pipe for producing notifications.
const NOTIFY_KEY: usize = usize::MAX;
/// A list of reported I/O events.
pub struct Events {
list: Box<[libc::kevent]>,
len: usize,
}
unsafe impl Send for Events {}
impl Events {
/// Creates an empty list.
pub fn new() -> Events {
let ev = libc::kevent {
ident: 0 as _,
filter: 0,
flags: 0,
fflags: 0,
data: 0,
udata: 0 as _,
};
let list = vec![ev; 1000].into_boxed_slice();
let len = 0;
Events { list, len }
}
/// Iterates over I/O events.
pub fn iter(&self) -> impl Iterator<Item = Event> + '_ {
// On some platforms, closing the read end of a pipe wakes up writers, but the
// event is reported as EVFILT_READ with the EV_EOF flag.
//
// https://github.com/golang/go/commit/23aad448b1e3f7c3b4ba2af90120bde91ac865b4
self.list[..self.len].iter().map(|ev| Event {
key: ev.udata as usize,
readable: ev.filter == libc::EVFILT_READ,
writable: ev.filter == libc::EVFILT_WRITE
|| (ev.filter == libc::EVFILT_READ && (ev.flags & libc::EV_EOF) != 0),
})
}
}

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//! Portable interface to epoll, kqueue, and wepoll.
//!
//! Supported platforms:
//! - [epoll](https://en.wikipedia.org/wiki/Epoll): Linux, Android, illumos
//! - [kqueue](https://en.wikipedia.org/wiki/Kqueue): macOS, iOS, FreeBSD, NetBSD, OpenBSD,
//! DragonFly BSD
//! - [wepoll](https://github.com/piscisaureus/wepoll): Windows
//!
//! Polling is done in oneshot mode, which means interest in I/O events needs to be reset after
//! an event is delivered if we're interested in the next event of the same kind.
//!
//! Only one thread can be waiting for I/O events at a time.
//!
//! # Examples
//!
//! ```no_run
//! use polling::{Event, Poller};
//! use std::net::TcpListener;
//!
//! // Create a TCP listener and put the socket in non-blocking mode.
//! let socket = TcpListener::bind("127.0.0.1:8000")?;
//! socket.set_nonblocking(true)?;
//! let key = 7; // arbitrary key identifying the socket
//!
//! // Create a poller and register interest in readability on the socket.
//! let poller = Poller::new()?;
//! poller.insert(&socket)?;
//! poller.interest(&socket, Event::readable(key))?;
//!
//! // The event loop.
//! let mut events = Vec::new();
//! loop {
//! // Wait for at least one I/O event.
//! events.clear();
//! poller.wait(&mut events, None)?;
//!
//! for ev in &events {
//! if ev.key == key {
//! // Perform a non-blocking accept operation.
//! socket.accept()?;
//! // Set interest in the next readability event.
//! poller.interest(&socket, Event::readable(key))?;
//! }
//! }
//! }
//! # std::io::Result::Ok(())
//! ```
#![warn(missing_docs, missing_debug_implementations, rust_2018_idioms)]
use std::fmt;
use std::io;
use std::sync::Mutex;
use std::time::Duration;
use std::usize;
use cfg_if::cfg_if;
/// Calls a libc function and results in `io::Result`.
#[cfg(unix)]
macro_rules! syscall {
($fn:ident $args:tt) => {{
let res = unsafe { libc::$fn $args };
if res == -1 {
Err(std::io::Error::last_os_error())
} else {
Ok(res)
}
}};
}
cfg_if! {
if #[cfg(any(target_os = "linux", target_os = "android", target_os = "illumos"))] {
mod epoll;
use epoll as sys;
} else if #[cfg(any(
target_os = "macos",
target_os = "ios",
target_os = "freebsd",
target_os = "netbsd",
target_os = "openbsd",
target_os = "dragonfly",
))] {
mod kqueue;
use kqueue as sys;
} else if #[cfg(target_os = "windows")] {
mod wepoll;
use wepoll as sys;
} else {
compile_error!("polling does not support this target OS");
}
}
/// Indicates that a file descriptor or socket can read or write without blocking.
#[derive(Debug)]
pub struct Event {
/// Key identifying the file descriptor or socket.
pub key: usize,
/// Can it do a read operation without blocking?
pub readable: bool,
/// Can it do a write operation without blocking?
pub writable: bool,
}
impl Event {
/// All kinds of events (readable and writable).
///
/// Equivalent to: `Event { key, readable: true, writable: true }`
pub fn all(key: usize) -> Event {
Event {
key,
readable: true,
writable: true,
}
}
/// Only the readable event.
///
/// Equivalent to: `Event { key, readable: true, writable: false }`
pub fn readable(key: usize) -> Event {
Event {
key,
readable: true,
writable: false,
}
}
/// Only the writable event.
///
/// Equivalent to: `Event { key, readable: false, writable: true }`
pub fn writable(key: usize) -> Event {
Event {
key,
readable: false,
writable: true,
}
}
/// No events.
///
/// Equivalent to: `Event { key, readable: false, writable: false }`
pub fn none(key: usize) -> Event {
Event {
key,
readable: true,
writable: true,
}
}
}
/// Waits for I/O events.
pub struct Poller {
poller: sys::Poller,
events: Mutex<sys::Events>,
}
impl Poller {
/// Creates a new poller.
///
/// # Examples
///
/// ```
/// use polling::Poller;
///
/// let poller = Poller::new()?;
/// # std::io::Result::Ok(())
/// ```
pub fn new() -> io::Result<Poller> {
let poller = sys::Poller::new()?;
let events = Mutex::new(sys::Events::new());
Ok(Poller { poller, events })
}
/// Inserts a file descriptor or socket into the poller.
///
/// Before setting interest in readability or writability, the file descriptor or socket must
/// be inserted into the poller.
///
/// Don't forget to [remove][`Poller::remove()`] it when it is no longer used!
///
/// # Examples
///
/// ```
/// use polling::Poller;
/// use std::net::TcpListener;
///
/// let poller = Poller::new()?;
/// let socket = TcpListener::bind("127.0.0.1:0")?;
///
/// poller.insert(&socket)?;
/// # std::io::Result::Ok(())
/// ```
pub fn insert(&self, source: impl Source) -> io::Result<()> {
self.poller.insert(source.raw())
}
/// Enables or disables interest in a file descriptor or socket.
///
/// A file descriptor or socket is considered readable or writable when a read or write
/// operation on it would not block. This doesn't mean the read or write operation will
/// succeed, it only means the operation will return immediately.
///
/// If interest is set in both readability and writability, the two kinds of events might be
/// delivered either separately or together.
///
/// For example, interest in `Event { key: 7, readable: true, writable: true }` might result in
/// a single [`Event`] of the same form, or in two separate [`Event`]s:
/// - `Event { key: 7, readable: true, writable: false }`
/// - `Event { key: 7, readable: false, writable: true }`
///
/// # Errors
///
/// This method returns an error in the following situations:
///
/// * If `source` was not [inserted][`Poller::interest()`] into the poller.
/// * If `key` equals `usize::MAX` because that key is reserved for internal use.
/// * If an error is returned by the syscall.
///
/// # Examples
///
/// To enable interest in all events:
///
/// ```no_run
/// # use polling::{Event, Poller};
/// # let poller = Poller::new()?;
/// # let key = 7;
/// # let source = std::net::TcpListener::bind("127.0.0.1:0")?;
/// poller.interest(&source, Event::all(key))?;
/// # std::io::Result::Ok(())
/// ```
///
/// To enable interest in readable events and disable interest in writable events:
///
/// ```no_run
/// # use polling::{Event, Poller};
/// # let poller = Poller::new()?;
/// # let key = 7;
/// # let source = std::net::TcpListener::bind("127.0.0.1:0")?;
/// poller.interest(&source, Event::readable(key))?;
/// # std::io::Result::Ok(())
/// ```
///
/// To disable interest in readable events and enable interest in writable events:
///
/// ```no_run
/// # use polling::{Event, Poller};
/// # let poller = Poller::new()?;
/// # let key = 7;
/// # let source = std::net::TcpListener::bind("127.0.0.1:0")?;
/// poller.interest(&source, Event::writable(key))?;
/// # std::io::Result::Ok(())
/// ```
///
/// To disable interest in all events:
///
/// ```no_run
/// # use polling::{Event, Poller};
/// # let poller = Poller::new()?;
/// # let key = 7;
/// # let source = std::net::TcpListener::bind("127.0.0.1:0")?;
/// poller.interest(&source, Event::none(key))?;
/// # std::io::Result::Ok(())
/// ```
pub fn interest(&self, source: impl Source, event: Event) -> io::Result<()> {
if event.key == usize::MAX {
Err(io::Error::new(
io::ErrorKind::InvalidInput,
"the key cannot be `usize::MAX`",
))
} else {
self.poller.interest(source.raw(), event)
}
}
/// Removes a file descriptor or socket from the poller.
///
/// # Examples
///
/// ```
/// use polling::Poller;
/// use std::net::TcpListener;
///
/// let poller = Poller::new()?;
/// let socket = TcpListener::bind("127.0.0.1:0")?;
///
/// poller.insert(&socket)?;
/// poller.remove(&socket)?;
/// # std::io::Result::Ok(())
/// ```
pub fn remove(&self, source: impl Source) -> io::Result<()> {
self.poller.remove(source.raw())
}
/// Waits for at least one I/O event and returns the number of new events.
///
/// New events will be appended to `events`.
///
/// This call will return with no new events if a notification is delivered by the [`notify()`]
/// method, or the timeout is reached.
///
/// Only one thread can wait on I/O. If another thread is already in [`wait()`], concurrent
/// calls to this method will return immediately with no new events.
///
/// If the operating system is ready to deliver a large number of events at once, this method
/// may decide to deliver them in smaller batches.
///
/// [`notify()`]: `Poller::notify()`
/// [`wait()`]: `Poller::wait()`
///
/// # Examples
///
/// ```
/// use polling::Poller;
/// use std::net::TcpListener;
/// use std::time::Duration;
///
/// let poller = Poller::new()?;
/// let socket = TcpListener::bind("127.0.0.1:0")?;
/// poller.insert(&socket)?;
///
/// let mut events = Vec::new();
/// let n = poller.wait(&mut events, Some(Duration::from_secs(1)))?;
/// # std::io::Result::Ok(())
/// ```
pub fn wait(&self, events: &mut Vec<Event>, timeout: Option<Duration>) -> io::Result<usize> {
if let Ok(mut lock) = self.events.try_lock() {
let n = self.poller.wait(&mut lock, timeout)?;
events.extend(lock.iter().filter(|ev| ev.key != usize::MAX));
Ok(n)
} else {
Ok(0)
}
}
/// Wakes up the current or the following invocation of [`wait()`].
///
/// If no thread is calling [`wait()`] right now, this method will cause the following call
/// to wake up immediately.
///
/// [`wait()`]: `Poller::wait()`
///
/// # Examples
///
/// ```
/// use polling::Poller;
///
/// let poller = Poller::new()?;
///
/// // Notify the poller.
/// poller.notify()?;
///
/// let mut events = Vec::new();
/// poller.wait(&mut events, None)?; // wakes up immediately
/// assert!(events.is_empty());
/// # std::io::Result::Ok(())
/// ```
pub fn notify(&self) -> io::Result<()> {
self.poller.notify()
}
}
impl fmt::Debug for Poller {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.poller.fmt(f)
}
}
cfg_if! {
if #[cfg(unix)] {
use std::os::unix::io::{AsRawFd, RawFd};
/// A [`RawFd`] or a reference to a type implementing [`AsRawFd`].
pub trait Source {
/// Returns the [`RawFd`] for this I/O object.
fn raw(&self) -> RawFd;
}
impl Source for RawFd {
fn raw(&self) -> RawFd {
*self
}
}
impl<T: AsRawFd> Source for &T {
fn raw(&self) -> RawFd {
self.as_raw_fd()
}
}
} else if #[cfg(windows)] {
use std::os::windows::io::{AsRawSocket, RawSocket};
/// A [`RawSocket`] or a reference to a type implementing [`AsRawSocket`].
pub trait Source {
/// Returns the [`RawSocket`] for this I/O object.
fn raw(&self) -> RawSocket;
}
impl Source for RawSocket {
fn raw(&self) -> RawSocket {
*self
}
}
impl<T: AsRawSocket> Source for &T {
fn raw(&self) -> RawSocket {
self.as_raw_fd()
}
}
}
}

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//! Bindings to wepoll (Windows).
use std::convert::TryInto;
use std::io;
use std::os::windows::io::RawSocket;
use std::ptr;
use std::time::Duration;
use wepoll_sys_stjepang as we;
use winapi::um::winsock2;
use crate::Event;
/// Calls a wepoll function and results in `io::Result`.
macro_rules! wepoll {
($fn:ident $args:tt) => {{
let res = unsafe { we::$fn $args };
if res == -1 {
Err(std::io::Error::last_os_error())
} else {
Ok(res)
}
}};
}
/// Interface to wepoll.
#[derive(Debug)]
pub struct Poller {
handle: we::HANDLE,
}
unsafe impl Send for Poller {}
unsafe impl Sync for Poller {}
impl Poller {
/// Creates a new poller.
pub fn new() -> io::Result<Poller> {
let handle = unsafe { we::epoll_create1(0) };
if handle.is_null() {
return Err(io::Error::last_os_error());
}
Ok(Poller { handle })
}
/// Inserts a socket.
pub fn insert(&self, sock: RawSocket) -> io::Result<()> {
// Put the socket in non-blocking mode.
unsafe {
let mut nonblocking = true as libc::c_ulong;
let res = winsock2::ioctlsocket(
sock as winsock2::SOCKET,
winsock2::FIONBIO,
&mut nonblocking,
);
if res != 0 {
return Err(io::Error::last_os_error());
}
}
// Register the socket in wepoll.
let mut ev = we::epoll_event {
events: 0,
data: we::epoll_data { u64: 0u64 },
};
wepoll!(epoll_ctl(
self.handle,
we::EPOLL_CTL_ADD as libc::c_int,
sock as we::SOCKET,
&mut ev,
))?;
Ok(())
}
/// Sets interest in a read/write event on a socket and associates a key with it.
pub fn interest(&self, sock: RawSocket, key: usize, read: bool, write: bool) -> io::Result<()> {
let mut flags = we::EPOLLONESHOT;
if read {
flags |= READ_FLAGS;
}
if write {
flags |= WRITE_FLAGS;
}
let mut ev = we::epoll_event {
events: flags as u32,
data: we::epoll_data { u64: key as u64 },
};
wepoll!(epoll_ctl(
self.handle,
we::EPOLL_CTL_MOD as libc::c_int,
sock as we::SOCKET,
&mut ev,
))?;
Ok(())
}
/// Removes a socket.
pub fn remove(&self, sock: RawSocket) -> io::Result<()> {
wepoll!(epoll_ctl(
self.handle,
we::EPOLL_CTL_DEL as libc::c_int,
sock as we::SOCKET,
ptr::null_mut(),
))?;
Ok(())
}
/// Waits for I/O events with an optional timeout.
///
/// Returns the number of processed I/O events.
///
/// If a notification occurs, this method will return but the notification event will not be
/// included in the `events` list nor contribute to the returned count.
pub fn wait(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<usize> {
// Convert the timeout to milliseconds.
let timeout_ms = match timeout {
None => -1,
Some(t) => {
if t == Duration::from_millis(0) {
0
} else {
// Non-zero duration must be at least 1ms.
t.max(Duration::from_millis(1))
.as_millis()
.try_into()
.unwrap_or(libc::c_int::max_value())
}
}
};
// Wait for I/O events.
events.len = wepoll!(epoll_wait(
self.handle,
events.list.as_mut_ptr(),
events.list.len() as libc::c_int,
timeout_ms,
))? as usize;
Ok(events.len)
}
/// Sends a notification to wake up the current or next `wait()` call.
pub fn notify(&self) -> io::Result<()> {
unsafe {
// This call errors if a notification has already been posted, but that's okay - we can
// just ignore the error.
//
// The original wepoll does not support notifications triggered this way, which is why
// this crate depends on a patched version of wepoll, wepoll-sys-stjepang.
winapi::um::ioapiset::PostQueuedCompletionStatus(
self.handle as winapi::um::winnt::HANDLE,
0,
0,
ptr::null_mut(),
);
}
Ok(())
}
}
impl Drop for Poller {
fn drop(&mut self) {
unsafe {
we::epoll_close(self.handle);
}
}
}
/// Wepoll flags for all possible readability events.
const READ_FLAGS: u32 = we::EPOLLIN | we::EPOLLRDHUP | we::EPOLLHUP | we::EPOLLERR | we::EPOLLPRI;
/// Wepoll flags for all possible writability events.
const WRITE_FLAGS: u32 = we::EPOLLOUT | we::EPOLLHUP | we::EPOLLERR;
/// A list of reported I/O events.
pub struct Events {
list: Box<[we::epoll_event]>,
len: usize,
}
unsafe impl Send for Events {}
impl Events {
/// Creates an empty list.
pub fn new() -> Events {
let ev = we::epoll_event {
events: 0,
data: we::epoll_data { u64: 0 },
};
Events {
list: vec![ev; 1000].into_boxed_slice(),
len: 0,
}
}
/// Iterates over I/O events.
pub fn iter(&self) -> impl Iterator<Item = Event> + '_ {
self.list[..self.len].iter().map(|ev| Event {
key: unsafe { ev.data.u64 } as usize,
readable: (ev.events & READ_FLAGS) != 0,
writable: (ev.events & WRITE_FLAGS) != 0,
})
}
}