openethereum/crates/runtime/io/src/lib.rs
2021-01-18 09:34:48 +01:00

313 lines
9.5 KiB
Rust

// Copyright 2015-2020 Parity Technologies (UK) Ltd.
// This file is part of OpenEthereum.
// OpenEthereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// OpenEthereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with OpenEthereum. If not, see <http://www.gnu.org/licenses/>.
//! General IO module.
//!
//! Example usage for creating a network service and adding an IO handler:
//!
//! ```rust
//! extern crate ethcore_io;
//! use ethcore_io::*;
//! use std::sync::Arc;
//! use std::time::Duration;
//!
//! struct MyHandler;
//!
//! #[derive(Clone)]
//! struct MyMessage {
//! data: u32
//! }
//!
//! impl IoHandler<MyMessage> for MyHandler {
//! fn initialize(&self, io: &IoContext<MyMessage>) {
//! io.register_timer(0, Duration::from_secs(1)).unwrap();
//! }
//!
//! fn timeout(&self, _io: &IoContext<MyMessage>, timer: TimerToken) {
//! println!("Timeout {}", timer);
//! }
//!
//! fn message(&self, _io: &IoContext<MyMessage>, message: &MyMessage) {
//! println!("Message {}", message.data);
//! }
//! }
//!
//! fn main () {
//! let mut service = IoService::<MyMessage>::start("name").expect("Error creating network service");
//! service.register_handler(Arc::new(MyHandler)).unwrap();
//!
//! // Wait for quit condition
//! // ...
//! // Drop the service
//! }
//! ```
//!
//! # Mio vs non-mio
//!
//! This library has two modes: mio and not mio. The `mio` feature can be activated or deactivated
//! when compiling or depending on the library.
//!
//! Without mio, only timers and message-passing are available. With mio, you can also use
//! low-level sockets provided by mio.
//!
//! The non-mio mode exists because the `mio` library doesn't compile on platforms such as
//! emscripten.
//TODO: use Poll from mio
#![allow(deprecated)]
#[cfg(feature = "mio")]
extern crate mio;
#[macro_use]
extern crate log as rlog;
extern crate crossbeam_deque as deque;
extern crate fnv;
extern crate futures;
extern crate num_cpus;
extern crate parking_lot;
extern crate slab;
extern crate time;
extern crate timer;
extern crate tokio;
#[cfg(feature = "mio")]
mod service_mio;
#[cfg(not(feature = "mio"))]
mod service_non_mio;
#[cfg(feature = "mio")]
mod worker;
#[cfg(feature = "mio")]
use mio::deprecated::{EventLoop, NotifyError};
#[cfg(feature = "mio")]
use mio::Token;
use std::{cell::Cell, error, fmt};
thread_local! {
/// Stack size
/// Should be modified if it is changed in Rust since it is no way
/// to know or get it
pub static LOCAL_STACK_SIZE: Cell<usize> = Cell::new(::std::env::var("RUST_MIN_STACK").ok().and_then(|s| s.parse().ok()).unwrap_or(2 * 1024 * 1024));
}
#[derive(Debug)]
/// IO Error
pub enum IoError {
/// Low level error from mio crate
#[cfg(feature = "mio")]
Mio(::std::io::Error),
/// Error concerning the Rust standard library's IO subsystem.
StdIo(::std::io::Error),
}
impl fmt::Display for IoError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
// just defer to the std implementation for now.
// we can refine the formatting when more variants are added.
match *self {
#[cfg(feature = "mio")]
IoError::Mio(ref std_err) => std_err.fmt(f),
IoError::StdIo(ref std_err) => std_err.fmt(f),
}
}
}
impl error::Error for IoError {
fn description(&self) -> &str {
"IO error"
}
}
impl From<::std::io::Error> for IoError {
fn from(err: ::std::io::Error) -> IoError {
IoError::StdIo(err)
}
}
#[cfg(feature = "mio")]
impl<Message> From<NotifyError<service_mio::IoMessage<Message>>> for IoError
where
Message: Send,
{
fn from(_err: NotifyError<service_mio::IoMessage<Message>>) -> IoError {
IoError::Mio(::std::io::Error::new(
::std::io::ErrorKind::ConnectionAborted,
"Network IO notification error",
))
}
}
/// Generic IO handler.
/// All the handler function are called from within IO event loop.
/// `Message` type is used as notification data
pub trait IoHandler<Message>: Send + Sync
where
Message: Send + Sync + 'static,
{
/// Initialize the handler
fn initialize(&self, _io: &IoContext<Message>) {}
/// Timer function called after a timeout created with `HandlerIo::timeout`.
fn timeout(&self, _io: &IoContext<Message>, _timer: TimerToken) {}
/// Called when a broadcasted message is received. The message can only be sent from a different IO handler.
fn message(&self, _io: &IoContext<Message>, _message: &Message) {}
/// Called when an IO stream gets closed
#[cfg(feature = "mio")]
fn stream_hup(&self, _io: &IoContext<Message>, _stream: StreamToken) {}
/// Called when an IO stream can be read from
#[cfg(feature = "mio")]
fn stream_readable(&self, _io: &IoContext<Message>, _stream: StreamToken) {}
/// Called when an IO stream can be written to
#[cfg(feature = "mio")]
fn stream_writable(&self, _io: &IoContext<Message>, _stream: StreamToken) {}
/// Register a new stream with the event loop
#[cfg(feature = "mio")]
fn register_stream(
&self,
_stream: StreamToken,
_reg: Token,
_event_loop: &mut EventLoop<IoManager<Message>>,
) {
}
/// Re-register a stream with the event loop
#[cfg(feature = "mio")]
fn update_stream(
&self,
_stream: StreamToken,
_reg: Token,
_event_loop: &mut EventLoop<IoManager<Message>>,
) {
}
/// Deregister a stream. Called whenstream is removed from event loop
#[cfg(feature = "mio")]
fn deregister_stream(
&self,
_stream: StreamToken,
_event_loop: &mut EventLoop<IoManager<Message>>,
) {
}
}
#[cfg(feature = "mio")]
pub use service_mio::{
IoChannel, IoContext, IoManager, IoService, StreamToken, TimerToken, TOKENS_PER_HANDLER,
};
#[cfg(not(feature = "mio"))]
pub use service_non_mio::{IoChannel, IoContext, IoService, TimerToken, TOKENS_PER_HANDLER};
#[cfg(test)]
mod tests {
use super::*;
use std::{
sync::{atomic, Arc},
thread,
time::Duration,
};
// Mio's behaviour is too unstable for this test. Sometimes we have to wait a few milliseconds,
// sometimes more than 5 seconds for the message to arrive.
// Therefore we ignore this test in order to not have spurious failure when running continuous
// integration.
#[test]
#[cfg_attr(feature = "mio", ignore)]
fn send_message_to_handler() {
struct MyHandler(atomic::AtomicBool);
#[derive(Clone)]
struct MyMessage {
data: u32,
}
impl IoHandler<MyMessage> for MyHandler {
fn message(&self, _io: &IoContext<MyMessage>, message: &MyMessage) {
assert_eq!(message.data, 5);
self.0.store(true, atomic::Ordering::SeqCst);
}
}
let handler = Arc::new(MyHandler(atomic::AtomicBool::new(false)));
let service =
IoService::<MyMessage>::start("Test").expect("Error creating network service");
service.register_handler(handler.clone()).unwrap();
service.send_message(MyMessage { data: 5 }).unwrap();
thread::sleep(Duration::from_secs(1));
assert!(handler.0.load(atomic::Ordering::SeqCst));
}
#[test]
fn timeout_working() {
struct MyHandler(atomic::AtomicBool);
#[derive(Clone)]
struct MyMessage {
data: u32,
}
impl IoHandler<MyMessage> for MyHandler {
fn initialize(&self, io: &IoContext<MyMessage>) {
io.register_timer_once(1234, Duration::from_millis(500))
.unwrap();
}
fn timeout(&self, _io: &IoContext<MyMessage>, timer: TimerToken) {
assert_eq!(timer, 1234);
assert!(!self.0.swap(true, atomic::Ordering::SeqCst));
}
}
let handler = Arc::new(MyHandler(atomic::AtomicBool::new(false)));
let service =
IoService::<MyMessage>::start("Test").expect("Error creating network service");
service.register_handler(handler.clone()).unwrap();
thread::sleep(Duration::from_secs(2));
assert!(handler.0.load(atomic::Ordering::SeqCst));
}
#[test]
fn multi_timeout_working() {
struct MyHandler(atomic::AtomicUsize);
#[derive(Clone)]
struct MyMessage {
data: u32,
}
impl IoHandler<MyMessage> for MyHandler {
fn initialize(&self, io: &IoContext<MyMessage>) {
io.register_timer(1234, Duration::from_millis(500)).unwrap();
}
fn timeout(&self, _io: &IoContext<MyMessage>, timer: TimerToken) {
assert_eq!(timer, 1234);
self.0.fetch_add(1, atomic::Ordering::SeqCst);
}
}
let handler = Arc::new(MyHandler(atomic::AtomicUsize::new(0)));
let service =
IoService::<MyMessage>::start("Test").expect("Error creating network service");
service.register_handler(handler.clone()).unwrap();
thread::sleep(Duration::from_secs(2));
assert!(handler.0.load(atomic::Ordering::SeqCst) >= 2);
}
}