Make sure ownership is transferred in into_raw_fd

Previously all of the into_raw_fd implementations only returns a copy of
the inner RawFd, while still holding the ownership of the file
descriptor when returning for into_raw_fd. Since `self` is dropped at
the end of into_raw_fd, the returned file descriptor will actually be
closed, render the function unuseable.

The patch makes sure that into_raw_fd actually takes the ownership of
the file descriptor all the way from the inner IoHandle. To achieve
this, I have to use an Option in IoHandle to store the I/O source. It's
not pretty, but I cannot come up with a better way.

src/net/driver/mod.rs

@@ -183,7 +183,7 @@ pub struct IoHandle<T: Evented> {
     entry: Arc<Entry>,
 
     /// The I/O event source.
-    source: T,
+    source: Option<T>,
 }
 
 impl<T: Evented> IoHandle<T> {
@@ -196,13 +196,13 @@ impl<T: Evented> IoHandle<T> {
             entry: REACTOR
                 .register(&source)
                 .expect("cannot register an I/O event source"),
-            source,
+            source: Some(source),
         }
     }
 
     /// Returns a reference to the inner I/O event source.
     pub fn get_ref(&self) -> &T {
-        &self.source
+        self.source.as_ref().unwrap()
     }
 
     /// Polls the I/O handle for reading.
@@ -278,15 +278,28 @@ impl<T: Evented> IoHandle<T> {
 
         Ok(())
     }
+
+    /// Deregister and return the I/O source
+    ///
+    /// This method is to support IntoRawFd in struct that uses IoHandle
+    pub fn into_inner(mut self) -> T {
+        let source = self.source.take().unwrap();
+        REACTOR
+            .deregister(&source, &self.entry)
+            .expect("cannot deregister I/O event source");
+        source
+    }
 }
 
 impl<T: Evented> Drop for IoHandle<T> {
     fn drop(&mut self) {
+        if let Some(ref source) = self.source {
             REACTOR
-            .deregister(&self.source, &self.entry)
+                .deregister(source, &self.entry)
                 .expect("cannot deregister I/O event source");
         }
     }
+}
 
 impl<T: Evented + fmt::Debug> fmt::Debug for IoHandle<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -305,7 +318,7 @@ impl<T: Evented + std::io::Read + Unpin> AsyncRead for IoHandle<T> {
     ) -> Poll<io::Result<usize>> {
         futures_core::ready!(Pin::new(&mut *self).poll_readable(cx)?);
 
-        match self.source.read(buf) {
+        match self.source.as_mut().unwrap().read(buf) {
             Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
                 self.clear_readable(cx)?;
                 Poll::Pending
@@ -326,7 +339,7 @@ where
     ) -> Poll<io::Result<usize>> {
         futures_core::ready!(Pin::new(&mut *self).poll_readable(cx)?);
 
-        match (&self.source).read(buf) {
+        match self.source.as_ref().unwrap().read(buf) {
             Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
                 self.clear_readable(cx)?;
                 Poll::Pending
@@ -344,7 +357,7 @@ impl<T: Evented + std::io::Write + Unpin> AsyncWrite for IoHandle<T> {
     ) -> Poll<io::Result<usize>> {
         futures_core::ready!(self.poll_writable(cx)?);
 
-        match self.source.write(buf) {
+        match self.source.as_mut().unwrap().write(buf) {
             Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
                 self.clear_writable(cx)?;
                 Poll::Pending
@@ -356,7 +369,7 @@ impl<T: Evented + std::io::Write + Unpin> AsyncWrite for IoHandle<T> {
     fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
         futures_core::ready!(self.poll_writable(cx)?);
 
-        match self.source.flush() {
+        match self.source.as_mut().unwrap().flush() {
             Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
                 self.clear_writable(cx)?;
                 Poll::Pending
@@ -381,7 +394,7 @@ where
     ) -> Poll<io::Result<usize>> {
         futures_core::ready!(self.poll_writable(cx)?);
 
-        match (&self.source).write(buf) {
+        match self.get_ref().write(buf) {
             Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
                 self.clear_writable(cx)?;
                 Poll::Pending
@@ -393,7 +406,7 @@ where
     fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
         futures_core::ready!(self.poll_writable(cx)?);
 
-        match (&self.source).flush() {
+        match self.get_ref().flush() {
             Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
                 self.clear_writable(cx)?;
                 Poll::Pending

src/net/tcp/listener.rs

@@ -50,9 +50,6 @@ use crate::task::{Context, Poll};
 #[derive(Debug)]
 pub struct TcpListener {
     io_handle: IoHandle<mio::net::TcpListener>,
-
-    #[cfg(unix)]
-    raw_fd: std::os::unix::io::RawFd,
     // #[cfg(windows)]
     // raw_socket: std::os::windows::io::RawSocket,
 }
@@ -87,7 +84,6 @@ impl TcpListener {
                 Ok(mio_listener) => {
                     #[cfg(unix)]
                     let listener = TcpListener {
-                        raw_fd: mio_listener.as_raw_fd(),
                         io_handle: IoHandle::new(mio_listener),
                     };
 
@@ -136,7 +132,6 @@ impl TcpListener {
 
                     #[cfg(unix)]
                     let stream = TcpStream {
-                        raw_fd: mio_stream.as_raw_fd(),
                         io_handle: IoHandle::new(mio_stream),
                     };
 
@@ -243,7 +238,6 @@ impl From<std::net::TcpListener> for TcpListener {
 
         #[cfg(unix)]
         let listener = TcpListener {
-            raw_fd: mio_listener.as_raw_fd(),
             io_handle: IoHandle::new(mio_listener),
         };
 
@@ -273,7 +267,7 @@ cfg_if! {
     if #[cfg(any(unix, feature = "docs"))] {
         impl AsRawFd for TcpListener {
             fn as_raw_fd(&self) -> RawFd {
-                self.raw_fd
+                self.io_handle.get_ref().as_raw_fd()
             }
         }
 
@@ -285,7 +279,7 @@ cfg_if! {
 
         impl IntoRawFd for TcpListener {
             fn into_raw_fd(self) -> RawFd {
-                self.raw_fd
+                self.io_handle.into_inner().into_raw_fd()
             }
         }
     }

src/net/tcp/stream.rs

@@ -51,9 +51,6 @@ use crate::task::{Context, Poll};
 #[derive(Debug)]
 pub struct TcpStream {
     pub(super) io_handle: IoHandle<mio::net::TcpStream>,
-
-    #[cfg(unix)]
-    pub(super) raw_fd: std::os::unix::io::RawFd,
     // #[cfg(windows)]
     // pub(super) raw_socket: std::os::windows::io::RawSocket,
 }
@@ -103,7 +100,6 @@ impl TcpStream {
         let stream = mio::net::TcpStream::connect(&addr).map(|mio_stream| {
             #[cfg(unix)]
             let stream = TcpStream {
-                raw_fd: mio_stream.as_raw_fd(),
                 io_handle: IoHandle::new(mio_stream),
             };
 
@@ -445,7 +441,6 @@ impl From<std::net::TcpStream> for TcpStream {
 
         #[cfg(unix)]
         let stream = TcpStream {
-            raw_fd: mio_stream.as_raw_fd(),
             io_handle: IoHandle::new(mio_stream),
         };
 
@@ -475,7 +470,7 @@ cfg_if! {
     if #[cfg(any(unix, feature = "docs"))] {
         impl AsRawFd for TcpStream {
             fn as_raw_fd(&self) -> RawFd {
-                self.raw_fd
+                self.io_handle.get_ref().as_raw_fd()
             }
         }
 
@@ -487,7 +482,7 @@ cfg_if! {
 
         impl IntoRawFd for TcpStream {
             fn into_raw_fd(self) -> RawFd {
-                self.raw_fd
+                self.io_handle.into_inner().into_raw_fd()
             }
         }
     }

src/net/udp/mod.rs

@@ -48,9 +48,6 @@ use crate::task::Poll;
 #[derive(Debug)]
 pub struct UdpSocket {
     io_handle: IoHandle<mio::net::UdpSocket>,
-
-    #[cfg(unix)]
-    raw_fd: std::os::unix::io::RawFd,
     // #[cfg(windows)]
     // raw_socket: std::os::windows::io::RawSocket,
 }
@@ -82,7 +79,6 @@ impl UdpSocket {
                 Ok(mio_socket) => {
                     #[cfg(unix)]
                     let socket = UdpSocket {
-                        raw_fd: mio_socket.as_raw_fd(),
                         io_handle: IoHandle::new(mio_socket),
                     };
 
@@ -515,7 +511,6 @@ impl From<std::net::UdpSocket> for UdpSocket {
 
         #[cfg(unix)]
         let socket = UdpSocket {
-            raw_fd: mio_socket.as_raw_fd(),
             io_handle: IoHandle::new(mio_socket),
         };
 
@@ -545,7 +540,7 @@ cfg_if! {
     if #[cfg(any(unix, feature = "docs"))] {
         impl AsRawFd for UdpSocket {
             fn as_raw_fd(&self) -> RawFd {
-                self.raw_fd
+                self.io_handle.get_ref().as_raw_fd()
             }
         }
 
@@ -557,7 +552,7 @@ cfg_if! {
 
         impl IntoRawFd for UdpSocket {
             fn into_raw_fd(self) -> RawFd {
-                self.raw_fd
+                self.io_handle.into_inner().into_raw_fd()
             }
         }
     }

src/os/unix/net/datagram.rs

@@ -44,15 +44,12 @@ use crate::task::{blocking, Poll};
 pub struct UnixDatagram {
     #[cfg(not(feature = "docs"))]
     io_handle: IoHandle<mio_uds::UnixDatagram>,
-
-    raw_fd: RawFd,
 }
 
 impl UnixDatagram {
     #[cfg(not(feature = "docs"))]
     fn new(socket: mio_uds::UnixDatagram) -> UnixDatagram {
         UnixDatagram {
-            raw_fd: socket.as_raw_fd(),
             io_handle: IoHandle::new(socket),
         }
     }
@@ -362,7 +359,6 @@ impl From<std::os::unix::net::UnixDatagram> for UnixDatagram {
     fn from(datagram: std::os::unix::net::UnixDatagram) -> UnixDatagram {
         let mio_datagram = mio_uds::UnixDatagram::from_datagram(datagram).unwrap();
         UnixDatagram {
-            raw_fd: mio_datagram.as_raw_fd(),
             io_handle: IoHandle::new(mio_datagram),
         }
     }
@@ -370,7 +366,7 @@ impl From<std::os::unix::net::UnixDatagram> for UnixDatagram {
 
 impl AsRawFd for UnixDatagram {
     fn as_raw_fd(&self) -> RawFd {
-        self.raw_fd
+        self.io_handle.get_ref().as_raw_fd()
     }
 }
 
@@ -383,6 +379,6 @@ impl FromRawFd for UnixDatagram {
 
 impl IntoRawFd for UnixDatagram {
     fn into_raw_fd(self) -> RawFd {
-        self.raw_fd
+        self.io_handle.into_inner().into_raw_fd()
     }
 }

src/os/unix/net/listener.rs

@@ -50,8 +50,6 @@ use crate::task::{blocking, Context, Poll};
 pub struct UnixListener {
     #[cfg(not(feature = "docs"))]
     io_handle: IoHandle<mio_uds::UnixListener>,
-
-    raw_fd: RawFd,
 }
 
 impl UnixListener {
@@ -73,7 +71,6 @@ impl UnixListener {
         let listener = blocking::spawn(async move { mio_uds::UnixListener::bind(path) }).await?;
 
         Ok(UnixListener {
-            raw_fd: listener.as_raw_fd(),
             io_handle: IoHandle::new(listener),
         })
     }
@@ -102,7 +99,6 @@ impl UnixListener {
                 Ok(Some((io, addr))) => {
                     let mio_stream = mio_uds::UnixStream::from_stream(io)?;
                     let stream = UnixStream {
-                        raw_fd: mio_stream.as_raw_fd(),
                         io_handle: IoHandle::new(mio_stream),
                     };
                     Poll::Ready(Ok((stream, addr)))
@@ -214,7 +210,6 @@ impl From<std::os::unix::net::UnixListener> for UnixListener {
     fn from(listener: std::os::unix::net::UnixListener) -> UnixListener {
         let mio_listener = mio_uds::UnixListener::from_listener(listener).unwrap();
         UnixListener {
-            raw_fd: mio_listener.as_raw_fd(),
             io_handle: IoHandle::new(mio_listener),
         }
     }
@@ -222,7 +217,7 @@ impl From<std::os::unix::net::UnixListener> for UnixListener {
 
 impl AsRawFd for UnixListener {
     fn as_raw_fd(&self) -> RawFd {
-        self.raw_fd
+        self.io_handle.get_ref().as_raw_fd()
     }
 }
 
@@ -235,6 +230,6 @@ impl FromRawFd for UnixListener {
 
 impl IntoRawFd for UnixListener {
     fn into_raw_fd(self) -> RawFd {
-        self.raw_fd
+        self.io_handle.into_inner().into_raw_fd()
     }
 }

src/os/unix/net/stream.rs

@@ -42,8 +42,6 @@ use crate::task::{blocking, Context, Poll};
 pub struct UnixStream {
     #[cfg(not(feature = "docs"))]
     pub(super) io_handle: IoHandle<mio_uds::UnixStream>,
-
-    pub(super) raw_fd: RawFd,
 }
 
 impl UnixStream {
@@ -71,7 +69,6 @@ impl UnixStream {
         let mut state = {
             match blocking::spawn(async move { mio_uds::UnixStream::connect(path) }).await {
                 Ok(mio_stream) => State::Waiting(UnixStream {
-                    raw_fd: mio_stream.as_raw_fd(),
                     io_handle: IoHandle::new(mio_stream),
                 }),
                 Err(err) => State::Error(err),
@@ -124,11 +121,9 @@ impl UnixStream {
     pub fn pair() -> io::Result<(UnixStream, UnixStream)> {
         let (a, b) = mio_uds::UnixStream::pair()?;
         let a = UnixStream {
-            raw_fd: a.as_raw_fd(),
             io_handle: IoHandle::new(a),
         };
         let b = UnixStream {
-            raw_fd: b.as_raw_fd(),
             io_handle: IoHandle::new(b),
         };
         Ok((a, b))
@@ -271,7 +266,6 @@ impl From<std::os::unix::net::UnixStream> for UnixStream {
     fn from(stream: std::os::unix::net::UnixStream) -> UnixStream {
         let mio_stream = mio_uds::UnixStream::from_stream(stream).unwrap();
         UnixStream {
-            raw_fd: mio_stream.as_raw_fd(),
             io_handle: IoHandle::new(mio_stream),
         }
     }
@@ -279,7 +273,7 @@ impl From<std::os::unix::net::UnixStream> for UnixStream {
 
 impl AsRawFd for UnixStream {
     fn as_raw_fd(&self) -> RawFd {
-        self.raw_fd
+        self.io_handle.get_ref().as_raw_fd()
     }
 }
 
@@ -292,6 +286,6 @@ impl FromRawFd for UnixStream {
 
 impl IntoRawFd for UnixStream {
     fn into_raw_fd(self) -> RawFd {
-        self.raw_fd
+        self.io_handle.into_inner().into_raw_fd()
     }
 }

tests/uds.rs

@@ -38,5 +38,4 @@ fn into_raw_fd() -> io::Result<()> {
 
         Ok(())
     })
-
 }