Fix compiler warnings in util/io and upgrade to edition 2018 Upgrade mio to latest (#10953)

* Initial cleanup

* Fix compiler warnings in util/io and upgrade to edition 2018
Upgrade mio to latest version

* cleanup

* Update util/io/src/service_mio.rs

Co-Authored-By: Niklas Adolfsson <niklasadolfsson1@gmail.com>

* review suggestion

Cargo.lock

@@ -1024,7 +1024,7 @@ dependencies = [
  "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1167,7 +1167,7 @@ dependencies = [
  "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "lru-cache 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-bytes 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-crypto 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-path 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2380,14 +2380,13 @@ dependencies = [
 
 [[package]]
 name = "mio"
-version = "0.6.16"
+version = "0.6.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "lazycell 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2403,7 +2402,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "lazycell 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2413,7 +2412,7 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "miow 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2425,7 +2424,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2666,7 +2665,7 @@ dependencies = [
  "failure 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -4134,7 +4133,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-codec 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-current-thread 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-executor 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4202,7 +4201,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "mio-named-pipes 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -4216,7 +4215,7 @@ dependencies = [
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4251,7 +4250,7 @@ dependencies = [
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-io 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-reactor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -4298,7 +4297,7 @@ dependencies = [
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-codec 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-io 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-reactor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4314,7 +4313,7 @@ dependencies = [
  "iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "mio-uds 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-io 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-reactor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4732,7 +4731,7 @@ dependencies = [
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "httparse 1.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "mio-extras 2.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha-1 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4964,7 +4963,7 @@ dependencies = [
 "checksum memzero 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "93c0d11ac30a033511ae414355d80f70d9f29a44a49140face477117a1ee90db"
 "checksum mime 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)" = "0a907b83e7b9e987032439a387e187119cddafc92d5c2aaeb1d92580a793f630"
 "checksum mime_guess 2.0.0-alpha.6 (registry+https://github.com/rust-lang/crates.io-index)" = "30de2e4613efcba1ec63d8133f344076952090c122992a903359be5a4f99c3ed"
-"checksum mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)" = "71646331f2619b1026cc302f87a2b8b648d5c6dd6937846a16cc8ce0f347f432"
+"checksum mio 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)" = "83f51996a3ed004ef184e16818edc51fadffe8e7ca68be67f9dee67d84d0ff23"
 "checksum mio-extras 2.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "46e73a04c2fa6250b8d802134d56d554a9ec2922bf977777c805ea5def61ce40"
 "checksum mio-named-pipes 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "f5e374eff525ce1c5b7687c4cef63943e7686524a387933ad27ca7ec43779cb3"
 "checksum mio-uds 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)" = "966257a94e196b11bb43aca423754d87429960a768de9414f3691d6957abf125"

util/io/Cargo.toml

@@ -1,14 +1,15 @@
 [package]
+name = "ethcore-io"
 description = "Ethcore IO library"
+version = "1.12.0"
 homepage = "http://parity.io"
 license = "GPL-3.0"
-name = "ethcore-io"
-version = "1.12.0"
 authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
 
 [dependencies]
 fnv = "1.0"
-mio = { version = "0.6.8", optional = true }
+mio = { version = "0.6.19", optional = true }
 crossbeam-deque = "0.6"
 parking_lot = "0.8"
 log = "0.4"
@@ -18,3 +19,4 @@ timer = "0.2"
 time = "0.1"
 tokio = "0.1"
 futures = "0.1"
+

util/io/src/lib.rs

@@ -69,20 +69,6 @@
 //TODO: use Poll from mio
 #![allow(deprecated)]
 
-#[cfg(feature = "mio")]
-extern crate mio;
-#[macro_use]
-extern crate log as rlog;
-extern crate slab;
-extern crate crossbeam_deque as deque;
-extern crate parking_lot;
-extern crate num_cpus;
-extern crate timer;
-extern crate fnv;
-extern crate time;
-extern crate tokio;
-extern crate futures;
-
 #[cfg(feature = "mio")]
 mod service_mio;
 #[cfg(not(feature = "mio"))]
@@ -170,7 +156,7 @@ pub trait IoHandler<Message>: Send + Sync where Message: Send + Sync + 'static {
 	/// 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
+	/// Deregister a stream. Called when a stream is removed from the event loop
 	#[cfg(feature = "mio")]
 	fn deregister_stream(&self, _stream: StreamToken, _event_loop: &mut EventLoop<IoManager<Message>>) {}
 }
@@ -178,14 +164,15 @@ pub trait IoHandler<Message>: Send + Sync where Message: Send + Sync + 'static {
 #[cfg(feature = "mio")]
 pub use service_mio::{TimerToken, StreamToken, IoContext, IoService, IoChannel, IoManager, TOKENS_PER_HANDLER};
 #[cfg(not(feature = "mio"))]
-pub use service_non_mio::{TimerToken, IoContext, IoService, IoChannel, TOKENS_PER_HANDLER};
+pub use crate::service_non_mio::{TimerToken, IoContext, IoService, IoChannel, TOKENS_PER_HANDLER};
 
 #[cfg(test)]
 mod tests {
-	use std::sync::Arc;
+	use std::{
-	use std::sync::atomic;
+		sync::{Arc, atomic},
-	use std::thread;
+		thread,
-	use std::time::Duration;
+		time::Duration,
+	};
 	use super::*;
 
 	// Mio's behaviour is too unstable for this test. Sometimes we have to wait a few milliseconds,

util/io/src/service_mio.rs

@@ -14,19 +14,24 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity Ethereum.  If not, see <http://www.gnu.org/licenses/>.
 
+use std::collections::HashMap;
 use std::sync::{Arc, Weak};
 use std::thread::{self, JoinHandle};
-use std::collections::HashMap;
-use mio::*;
-use mio::timer::{Timeout};
-use mio::deprecated::{EventLoop, Handler, Sender, EventLoopBuilder};
-use deque;
-use slab::Slab;
-use {IoError, IoHandler};
-use worker::{Worker, Work, WorkType};
-use parking_lot::{Condvar, RwLock, Mutex};
 use std::time::Duration;
 
+use crossbeam_deque as deque;
+use log::{trace, debug, warn};
+use mio::*;
+use mio::deprecated::{EventLoop, EventLoopBuilder, Handler, Sender};
+use mio::timer::Timeout;
+use parking_lot::{Condvar, Mutex, RwLock};
+use slab::Slab;
+
+use crate::{
+	IoError, IoHandler,
+	worker::{Work, Worker, WorkType}
+};
+
 /// Timer ID
 pub type TimerToken = usize;
 /// Timer ID
@@ -45,7 +50,7 @@ pub enum IoMessage<Message> where Message: Send + Sized {
 	Shutdown,
 	/// Register a new protocol handler.
 	AddHandler {
-		handler: Arc<IoHandler<Message>+Send>,
+		handler: Arc<dyn IoHandler<Message> + Send>,
 	},
 	RemoveHandler {
 		handler_id: HandlerId,
@@ -182,7 +187,7 @@ struct UserTimer {
 /// Root IO handler. Manages user handlers, messages and IO timers.
 pub struct IoManager<Message> where Message: Send + Sync {
 	timers: Arc<RwLock<HashMap<HandlerId, UserTimer>>>,
-	handlers: Arc<RwLock<Slab<Arc<IoHandler<Message>>>>>,
+	handlers: Arc<RwLock<Slab<Arc<dyn IoHandler<Message>>>>>,
 	workers: Vec<Worker>,
 	worker_channel: deque::Worker<Work<Message>>,
 	work_ready: Arc<Condvar>,
@@ -192,7 +197,7 @@ impl<Message> IoManager<Message> where Message: Send + Sync + 'static {
 	/// Creates a new instance and registers it with the event loop.
 	pub fn start(
 		event_loop: &mut EventLoop<IoManager<Message>>,
-		handlers: Arc<RwLock<Slab<Arc<IoHandler<Message>>>>>
+		handlers: Arc<RwLock<Slab<Arc<dyn IoHandler<Message>>>>>
 	) -> Result<(), IoError> {
 		let (worker, stealer) = deque::fifo();
 		let num_workers = 4;
@@ -243,24 +248,6 @@ impl<Message> Handler for IoManager<Message> where Message: Send + Sync + 'stati
 		}
 	}
 
-	fn timeout(&mut self, event_loop: &mut EventLoop<Self>, token: Token) {
-		let handler_index  = token.0  / TOKENS_PER_HANDLER;
-		let token_id  = token.0  % TOKENS_PER_HANDLER;
-		if let Some(handler) = self.handlers.read().get(handler_index) {
-			let maybe_timer = self.timers.read().get(&token.0).cloned();
-			if let Some(timer) = maybe_timer {
-				if timer.once {
-					self.timers.write().remove(&token_id);
-					event_loop.clear_timeout(&timer.timeout);
-				} else {
-					event_loop.timeout(token, timer.delay).expect("Error re-registering user timer");
-				}
-				self.worker_channel.push(Work { work_type: WorkType::Timeout, token: token_id, handler: handler.clone(), handler_id: handler_index });
-				self.work_ready.notify_all();
-			}
-		}
-	}
-
 	fn notify(&mut self, event_loop: &mut EventLoop<Self>, msg: Self::Message) {
 		match msg {
 			IoMessage::Shutdown => {
@@ -331,11 +318,34 @@ impl<Message> Handler for IoManager<Message> where Message: Send + Sync + 'stati
 			}
 		}
 	}
+
+	fn timeout(&mut self, event_loop: &mut EventLoop<Self>, token: Token) {
+		let handler_index  = token.0  / TOKENS_PER_HANDLER;
+		let token_id  = token.0  % TOKENS_PER_HANDLER;
+		if let Some(handler) = self.handlers.read().get(handler_index) {
+			let maybe_timer = self.timers.read().get(&token.0).cloned();
+			if let Some(timer) = maybe_timer {
+				if timer.once {
+					self.timers.write().remove(&token_id);
+					event_loop.clear_timeout(&timer.timeout);
+				} else {
+					event_loop.timeout(token, timer.delay).expect("Error re-registering user timer");
+				}
+				self.worker_channel.push(Work {
+					work_type: WorkType::Timeout,
+					token: token_id,
+					handler: handler.clone(),
+					handler_id: handler_index
+				});
+				self.work_ready.notify_all();
+			}
+		}
+	}
 }
 
 enum Handlers<Message> where Message: Send {
-	SharedCollection(Weak<RwLock<Slab<Arc<IoHandler<Message>>>>>),
+	SharedCollection(Weak<RwLock<Slab<Arc<dyn IoHandler<Message>>>>>),
-	Single(Weak<IoHandler<Message>>),
+	Single(Weak<dyn IoHandler<Message>>),
 }
 
 impl<Message: Send> Clone for Handlers<Message> {
@@ -413,13 +423,13 @@ impl<Message> IoChannel<Message> where Message: Send + Sync + 'static {
 	}
 
 	/// Create a new synchronous channel to a given handler.
-	pub fn to_handler(handler: Weak<IoHandler<Message>>) -> IoChannel<Message> {
+	pub fn to_handler(handler: Weak<dyn IoHandler<Message>>) -> IoChannel<Message> {
 		IoChannel {
 			channel: None,
 			handlers: Handlers::Single(handler),
 		}
 	}
-	fn new(channel: Sender<IoMessage<Message>>, handlers: Weak<RwLock<Slab<Arc<IoHandler<Message>>>>>) -> IoChannel<Message> {
+	fn new(channel: Sender<IoMessage<Message>>, handlers: Weak<RwLock<Slab<Arc<dyn IoHandler<Message>>>>>) -> IoChannel<Message> {
 		IoChannel {
 			channel: Some(channel),
 			handlers: Handlers::SharedCollection(handlers),
@@ -432,7 +442,7 @@ impl<Message> IoChannel<Message> where Message: Send + Sync + 'static {
 pub struct IoService<Message> where Message: Send + Sync + 'static {
 	thread: Option<JoinHandle<()>>,
 	host_channel: Mutex<Sender<IoMessage<Message>>>,
-	handlers: Arc<RwLock<Slab<Arc<IoHandler<Message>>>>>,
+	handlers: Arc<RwLock<Slab<Arc<dyn IoHandler<Message>>>>>,
 }
 
 impl<Message> IoService<Message> where Message: Send + Sync + 'static {
@@ -469,7 +479,7 @@ impl<Message> IoService<Message> where Message: Send + Sync + 'static {
 	}
 
 	/// Regiter an IO handler with the event loop.
-	pub fn register_handler(&self, handler: Arc<IoHandler<Message>+Send>) -> Result<(), IoError> {
+	pub fn register_handler(&self, handler: Arc<dyn IoHandler<Message>+Send>) -> Result<(), IoError> {
 		self.host_channel.lock().send(IoMessage::AddHandler {
 			handler: handler,
 		})?;

util/io/src/service_non_mio.rs

@@ -16,15 +16,18 @@
 
 use std::sync::{Arc, Weak};
 use std::thread;
-use deque;
-use slab::Slab;
-use fnv::FnvHashMap;
-use {IoError, IoHandler};
-use parking_lot::{RwLock, Mutex};
-use num_cpus;
 use std::time::Duration;
-use timer::{Timer, Guard as TimerGuard};
+
+use crossbeam_deque as deque;
+use fnv::FnvHashMap;
+use log::{trace, debug};
+use num_cpus;
+use parking_lot::{Mutex, RwLock};
+use slab::Slab;
 use time::Duration as TimeDuration;
+use timer::{Guard as TimerGuard, Timer};
+
+use crate::{IoError, IoHandler};
 
 /// Timer ID
 pub type TimerToken = usize;
@@ -48,7 +51,7 @@ impl<Message> IoContext<Message> where Message: Send + Sync + 'static {
 
 		let msg = WorkTask::TimerTrigger {
 			handler_id: self.handler,
-			token: token,
+			token,
 		};
 
 		let delay = TimeDuration::from_std(delay)
@@ -68,7 +71,7 @@ impl<Message> IoContext<Message> where Message: Send + Sync + 'static {
 
 		let msg = WorkTask::TimerTrigger {
 			handler_id: self.handler,
-			token: token,
+			token,
 		};
 
 		let delay = TimeDuration::from_std(delay)
@@ -189,7 +192,7 @@ pub struct IoService<Message> where Message: Send + Sync + 'static {
 // Struct shared throughout the whole implementation.
 struct Shared<Message> where Message: Send + Sync + 'static {
 	// All the I/O handlers that have been registered.
-	handlers: RwLock<Slab<Arc<IoHandler<Message>>>>,
+	handlers: RwLock<Slab<Arc<dyn IoHandler<Message>>>>,
 	// All the background threads, so that we can unpark them.
 	threads: RwLock<Vec<thread::Thread>>,
 	// Used to create timeouts.
@@ -273,7 +276,7 @@ impl<Message> IoService<Message> where Message: Send + Sync + 'static {
 	}
 
 	/// Register an IO handler with the event loop.
-	pub fn register_handler(&self, handler: Arc<IoHandler<Message>+Send>) -> Result<(), IoError> {
+	pub fn register_handler(&self, handler: Arc<dyn IoHandler<Message>+Send>) -> Result<(), IoError> {
 		let id = self.shared.handlers.write().insert(handler.clone());
 		assert!(id <= MAX_HANDLERS, "Too many handlers registered");
 		let ctxt = IoContext { handler: id, shared: self.shared.clone() };

util/io/src/worker.rs

@@ -14,17 +14,22 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity Ethereum.  If not, see <http://www.gnu.org/licenses/>.
 
-use futures::future::{self, Loop};
+use std::{
-use std::sync::Arc;
+	sync::{Arc, atomic::{AtomicBool, Ordering as AtomicOrdering}},
-use std::thread::{JoinHandle, self};
+	thread::{self, JoinHandle},
-use std::sync::atomic::{AtomicBool, Ordering as AtomicOrdering};
+};
-use deque;
-use service_mio::{HandlerId, IoChannel, IoContext};
-use tokio::{self};
-use IoHandler;
-use LOCAL_STACK_SIZE;
 
+use crossbeam_deque as deque;
+use futures::future::{self, Loop};
+use log::{trace, error};
 use parking_lot::{Condvar, Mutex};
+use tokio;
+
+use crate::{
+	IoHandler,
+	LOCAL_STACK_SIZE,
+	service_mio::{HandlerId, IoChannel, IoContext},
+};
 
 const STACK_SIZE: usize = 16*1024*1024;
 
@@ -40,7 +45,7 @@ pub struct Work<Message> {
 	pub work_type: WorkType<Message>,
 	pub token: usize,
 	pub handler_id: HandlerId,
-	pub handler: Arc<IoHandler<Message>>,
+	pub handler: Arc<dyn IoHandler<Message>>,
 }
 
 /// An IO worker thread
@@ -54,13 +59,15 @@ pub struct Worker {
 
 impl Worker {
 	/// Creates a new worker instance.
-	pub fn new<Message>(index: usize,
+	pub fn new<Message>(
+		index: usize,
 		stealer: deque::Stealer<Work<Message>>,
 		channel: IoChannel<Message>,
 		wait: Arc<Condvar>,
 		wait_mutex: Arc<Mutex<()>>,
 	) -> Worker
-					where Message: Send + Sync + 'static {
+	where Message: Send + Sync + 'static
+	{
 		let deleting = Arc::new(AtomicBool::new(false));
 		let mut worker = Worker {
 			thread: None,