doc: document `from_std` functions panic (#2056)

Document that conversion from `std` types must be done from within
the Tokio runtime context.

1 files changed, 16 insertions, 0 deletions

diff --git a/tokio/src/net/unix/listener.rs b/tokio/src/net/unix/listener.rs
index 4b93bf82..d61d0392 100644
--- a/tokio/src/net/unix/listener.rs
+++ b/tokio/src/net/unix/listener.rs
@@ -21,6 +21,14 @@ cfg_uds! {
 
 impl UnixListener {
     /// Creates a new `UnixListener` bound to the specified path.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if thread-local runtime is not set.
+    ///
+    /// The runtime is usually set implicitly when this function is called
+    /// from a future driven by a tokio runtime, otherwise runtime can be set
+    /// explicitly with [`Handle::enter`](crate::runtime::Handle::enter) function.
     pub fn bind<P>(path: P) -> io::Result<UnixListener>
     where
         P: AsRef<Path>,
@@ -35,6 +43,14 @@ impl UnixListener {
     ///
     /// The returned listener will be associated with the given event loop
     /// specified by `handle` and is ready to perform I/O.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if thread-local runtime is not set.
+    ///
+    /// The runtime is usually set implicitly when this function is called
+    /// from a future driven by a tokio runtime, otherwise runtime can be set
+    /// explicitly with [`Handle::enter`](crate::runtime::Handle::enter) function.
     pub fn from_std(listener: net::UnixListener) -> io::Result<UnixListener> {
         let listener = mio_uds::UnixListener::from_listener(listener)?;
         let io = PollEvented::new(listener)?;