Don't wrap yamux::Connection in a mutex (#719)

Get rid of double mutex

* Use inherent `poll()` that takes an immutable ref

* Remove parking_lot dependency from yamux

* Update muxers/yamux/Cargo.toml

Co-Authored-By: dvdplm <dvdplm@gmail.com>

muxers/yamux/Cargo.toml

@@ -9,6 +9,5 @@ bytes = "0.4"
 futures = "0.1"
 libp2p-core = { path = "../../core" }
 log = "0.4"
-parking_lot = "0.7"
 tokio-io = "0.1"
-yamux = "0.1"
+yamux = "0.1.1"

muxers/yamux/src/lib.rs

@@ -23,27 +23,25 @@ extern crate futures;
 #[macro_use]
 extern crate log;
 extern crate libp2p_core;
-extern crate parking_lot;
 extern crate tokio_io;
 extern crate yamux;
 
 use bytes::Bytes;
 use futures::{future::{self, FutureResult}, prelude::*};
 use libp2p_core::{muxing::Shutdown, upgrade::{InboundUpgrade, OutboundUpgrade, UpgradeInfo}};
-use parking_lot::Mutex;
 use std::{io, iter};
 use std::io::{Error as IoError};
 use tokio_io::{AsyncRead, AsyncWrite};
 
 
-pub struct Yamux<C>(Mutex<yamux::Connection<C>>);
+pub struct Yamux<C>(yamux::Connection<C>);
 
 impl<C> Yamux<C>
 where
     C: AsyncRead + AsyncWrite + 'static
 {
     pub fn new(c: C, cfg: yamux::Config, mode: yamux::Mode) -> Self {
-        Yamux(Mutex::new(yamux::Connection::new(c, cfg, mode)))
+        Yamux(yamux::Connection::new(c, cfg, mode))
     }
 }
 
@@ -56,7 +54,7 @@ where
 
     #[inline]
     fn poll_inbound(&self) -> Poll<Option<Self::Substream>, IoError> {
-        match self.0.lock().poll() {
+        match self.0.poll() {
             Err(e) => {
                 error!("connection error: {}", e);
                 Err(io::Error::new(io::ErrorKind::Other, e))
@@ -69,7 +67,7 @@ where
 
     #[inline]
     fn open_outbound(&self) -> Self::OutboundSubstream {
-        let stream = self.0.lock().open_stream().map_err(|e| io::Error::new(io::ErrorKind::Other, e));
+        let stream = self.0.open_stream().map_err(|e| io::Error::new(io::ErrorKind::Other, e));
         future::result(stream)
     }
 
@@ -108,12 +106,12 @@ where
 
     #[inline]
     fn shutdown(&self, _: Shutdown) -> Poll<(), IoError> {
-        self.0.lock().shutdown()
+        self.0.shutdown()
     }
 
     #[inline]
     fn flush_all(&self) -> Poll<(), IoError> {
-        self.0.lock().flush()
+        self.0.flush()
     }
 }