don't init runtime threadpool unless necessary

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>

src/net/tcp/listener.rs

@@ -75,8 +75,6 @@ impl TcpListener {
     ///
     /// [`local_addr`]: #method.local_addr
     pub async fn bind<A: ToSocketAddrs>(addrs: A) -> io::Result<TcpListener> {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         let mut last_err = None;
         let addrs = addrs.to_socket_addrs().await?;
 
@@ -202,8 +200,6 @@ impl<'a> Stream for Incoming<'a> {
 impl From<std::net::TcpListener> for TcpListener {
     /// Converts a `std::net::TcpListener` into its asynchronous equivalent.
     fn from(listener: std::net::TcpListener) -> TcpListener {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         TcpListener {
             watcher: Async::new(listener).expect("TcpListener is known to be good"),
         }

src/net/tcp/stream.rs

@@ -71,8 +71,6 @@ impl TcpStream {
     /// # Ok(()) }) }
     /// ```
     pub async fn connect<A: ToSocketAddrs>(addrs: A) -> io::Result<TcpStream> {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         let mut last_err = None;
         let addrs = addrs.to_socket_addrs().await?;
 
@@ -358,8 +356,6 @@ impl Write for &TcpStream {
 impl From<std::net::TcpStream> for TcpStream {
     /// Converts a `std::net::TcpStream` into its asynchronous equivalent.
     fn from(stream: std::net::TcpStream) -> TcpStream {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         TcpStream {
             watcher: Arc::new(Async::new(stream).expect("TcpStream is known to be good")),
         }

src/net/udp/mod.rs

@@ -68,8 +68,6 @@ impl UdpSocket {
     /// # Ok(()) }) }
     /// ```
     pub async fn bind<A: ToSocketAddrs>(addrs: A) -> io::Result<UdpSocket> {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         let mut last_err = None;
         let addrs = addrs.to_socket_addrs().await?;
 
@@ -481,8 +479,6 @@ impl UdpSocket {
 impl From<std::net::UdpSocket> for UdpSocket {
     /// Converts a `std::net::UdpSocket` into its asynchronous equivalent.
     fn from(socket: std::net::UdpSocket) -> UdpSocket {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         UdpSocket {
             watcher: Async::new(socket).expect("UdpSocket is known to be good"),
         }

src/os/unix/net/datagram.rs

@@ -45,8 +45,6 @@ pub struct UnixDatagram {
 
 impl UnixDatagram {
     fn new(socket: StdUnixDatagram) -> UnixDatagram {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         UnixDatagram {
             watcher: Async::new(socket).expect("UnixDatagram is known to be good"),
         }
@@ -66,8 +64,6 @@ impl UnixDatagram {
     /// # Ok(()) }) }
     /// ```
     pub async fn bind<P: AsRef<Path>>(path: P) -> io::Result<UnixDatagram> {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         let path = path.as_ref().to_owned();
         let socket = Async::<StdUnixDatagram>::bind(path)?;
         Ok(UnixDatagram { watcher: socket })
@@ -309,8 +305,6 @@ impl fmt::Debug for UnixDatagram {
 impl From<StdUnixDatagram> for UnixDatagram {
     /// Converts a `std::os::unix::net::UnixDatagram` into its asynchronous equivalent.
     fn from(datagram: StdUnixDatagram) -> UnixDatagram {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         UnixDatagram {
             watcher: Async::new(datagram).expect("UnixDatagram is known to be good"),
         }
@@ -325,8 +319,6 @@ impl AsRawFd for UnixDatagram {
 
 impl FromRawFd for UnixDatagram {
     unsafe fn from_raw_fd(fd: RawFd) -> UnixDatagram {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         let raw = StdUnixDatagram::from_raw_fd(fd);
         let datagram = Async::<StdUnixDatagram>::new(raw).expect("invalid file descriptor");
         UnixDatagram { watcher: datagram }

src/os/unix/net/listener.rs

@@ -68,8 +68,6 @@ impl UnixListener {
     /// # Ok(()) }) }
     /// ```
     pub async fn bind<P: AsRef<Path>>(path: P) -> io::Result<UnixListener> {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         let path = path.as_ref().to_owned();
         let listener = Async::<StdUnixListener>::bind(path)?;
 
@@ -194,8 +192,6 @@ impl Stream for Incoming<'_> {
 impl From<StdUnixListener> for UnixListener {
     /// Converts a `std::os::unix::net::UnixListener` into its asynchronous equivalent.
     fn from(listener: StdUnixListener) -> UnixListener {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         UnixListener {
             watcher: Async::new(listener).expect("UnixListener is known to be good"),
         }

src/os/unix/net/stream.rs

@@ -57,8 +57,6 @@ impl UnixStream {
     /// # Ok(()) }) }
     /// ```
     pub async fn connect<P: AsRef<Path>>(path: P) -> io::Result<UnixStream> {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         let path = path.as_ref().to_owned();
         let stream = Arc::new(Async::<StdUnixStream>::connect(path).await?);
 
@@ -81,8 +79,6 @@ impl UnixStream {
     /// # Ok(()) }) }
     /// ```
     pub fn pair() -> io::Result<(UnixStream, UnixStream)> {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         let (a, b) = Async::<StdUnixStream>::pair()?;
         let a = UnixStream {
             watcher: Arc::new(a),
@@ -228,8 +224,6 @@ impl fmt::Debug for UnixStream {
 impl From<StdUnixStream> for UnixStream {
     /// Converts a `std::os::unix::net::UnixStream` into its asynchronous equivalent.
     fn from(stream: StdUnixStream) -> UnixStream {
-        once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
         let stream = Async::new(stream).expect("UnixStream is known to be good");
         UnixStream {
             watcher: Arc::new(stream),

src/utils.rs

@@ -66,9 +66,6 @@ mod timer {
 
 #[cfg(any(feature = "unstable", feature = "default"))]
 pub(crate) fn timer_after(dur: std::time::Duration) -> timer::Timer {
-    #[cfg(all(not(target_os = "unknown"), feature = "default"))]
-    once_cell::sync::Lazy::force(&crate::rt::RUNTIME);
-
     Timer::after(dur)
 }