From 614887b8c15943b4afae494af83a815058f128a3 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Sat, 5 Nov 2016 11:14:54 -0700
Subject: [PATCH] Implement split() with BiLock

---
 Cargo.toml      |  3 +++
 src/io/mod.rs   |  6 +-----
 src/io/split.rs | 37 ++++++++++++++++++++++++++-----------
 3 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 60d304b35..b16e52b2f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,3 +20,6 @@ slab = "0.3"
 
 [dev-dependencies]
 env_logger = { version = "0.3", default-features = false }
+
+[replace]
+'futures:0.1.3' = { git = "https://github.com/alexcrichton/futures-rs" }
diff --git a/src/io/mod.rs b/src/io/mod.rs
index 2263692fa..4648cf70f 100644
--- a/src/io/mod.rs
+++ b/src/io/mod.rs
@@ -109,11 +109,7 @@ pub trait Io: io::Read + io::Write {
     /// Helper method for splitting this read/write object into two halves.
     ///
     /// The two halves returned implement the `Read` and `Write` traits,
-    /// respectively, but are only usable on the current task.
-    ///
-    /// # Panics
-    ///
-    /// This method will panic if there is not currently an active future task.
+    /// respectively.
     fn split(self) -> (ReadHalf<Self>, WriteHalf<Self>)
         where Self: Sized
     {
diff --git a/src/io/split.rs b/src/io/split.rs
index 46b89308a..a012ed69a 100644
--- a/src/io/split.rs
+++ b/src/io/split.rs
@@ -1,31 +1,34 @@
-use std::cell::RefCell;
 use std::io::{self, Read, Write};
 
 use futures::Async;
-use futures::task::TaskRc;
+use futures::sync::BiLock;
+use mio;
 
 use io::Io;
 
 /// The readable half of an object returned from `Io::split`.
 pub struct ReadHalf<T> {
-    handle: TaskRc<RefCell<T>>,
+    handle: BiLock<T>,
 }
 
 /// The writable half of an object returned from `Io::split`.
 pub struct WriteHalf<T> {
-    handle: TaskRc<RefCell<T>>,
+    handle: BiLock<T>,
 }
 
 pub fn split<T: Io>(t: T) -> (ReadHalf<T>, WriteHalf<T>) {
-    let rc = TaskRc::new(RefCell::new(t));
-    (ReadHalf { handle: rc.clone() }, WriteHalf { handle: rc })
+    let (a, b) = BiLock::new(t);
+    (ReadHalf { handle: a }, WriteHalf { handle: b })
 }
 
 impl<T: Io> ReadHalf<T> {
     /// Calls the underlying `poll_read` function on this handling, testing to
     /// see if it's ready to be read from.
     pub fn poll_read(&mut self) -> Async<()> {
-        self.handle.with(|t| t.borrow_mut().poll_read())
+        match self.handle.poll_lock() {
+            Async::Ready(mut l) => l.poll_read(),
+            Async::NotReady => Async::NotReady,
+        }
     }
 }
 
@@ -33,22 +36,34 @@ impl<T: Io> WriteHalf<T> {
     /// Calls the underlying `poll_write` function on this handling, testing to
     /// see if it's ready to be written to.
     pub fn poll_write(&mut self) -> Async<()> {
-        self.handle.with(|t| t.borrow_mut().poll_write())
+        match self.handle.poll_lock() {
+            Async::Ready(mut l) => l.poll_write(),
+            Async::NotReady => Async::NotReady,
+        }
     }
 }
 
 impl<T: Read> Read for ReadHalf<T> {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        self.handle.with(|t| t.borrow_mut().read(buf))
+        match self.handle.poll_lock() {
+            Async::Ready(mut l) => l.read(buf),
+            Async::NotReady => Err(mio::would_block()),
+        }
     }
 }
 
 impl<T: Write> Write for WriteHalf<T> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        self.handle.with(|t| t.borrow_mut().write(buf))
+        match self.handle.poll_lock() {
+            Async::Ready(mut l) => l.write(buf),
+            Async::NotReady => Err(mio::would_block()),
+        }
     }
 
     fn flush(&mut self) -> io::Result<()> {
-        self.handle.with(|t| t.borrow_mut().flush())
+        match self.handle.poll_lock() {
+            Async::Ready(mut l) => l.flush(),
+            Async::NotReady => Err(mio::would_block()),
+        }
     }
 }