Close Tokio stream

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "async-send-fd"
-version = "1.1.0"
+version = "1.2.0"
 edition = "2021"
 authors = ["Alexander Smoktal [https://github.com/alexander-smoktal]"]
 license = "MIT"
@@ -20,6 +20,7 @@ smol = ["dep:smol"]
 passfd = "0.1"
 tokio = { version = "1", features = ["net", "io-util"], optional = true }
 smol = { version = "2", optional = true }
+nix = "0.28"
 
 [dev-dependencies]
 tempdir = "0.3"

README.md

@@ -25,9 +25,7 @@ If you make a Tokio [UnixStream](https://docs.rs/tokio/latest/tokio/net/struct.U
 Smol [UnixStream](https://docs.rs/smol/2.0.0/smol/net/unix/struct.UnixStream.html) does it automatically if created using `UnixStream::from(Async::new(stream))`
 
 ## Transfering socket pair ownership
-Sending a descriptor doesn't close the local copy, which leads to having the socket being opened by the sender until it shuts down.
-If you want socket pair receivers to detect peer shutdown, you have to close local sockets after sending them.
-Use [UnixStream::poll_shutdown()](https://docs.rs/tokio/latest/tokio/net/struct.UnixStream.html#method.poll_shutdown) for Tokio streams, or [UnixStream::shutdown()](https://docs.rs/smol/2.0.0/smol/net/unix/struct.UnixStream.html#method.shutdown) for Smol.
+Note: the library closes Tokio stream if sent into another process.
 
 ## Features
 - `tokio` - for Tokio support

src/tokio_stream.rs

@@ -5,6 +5,7 @@ use std::{
         net::UnixStream as OsUnixStream,
         prelude::{FromRawFd, IntoRawFd},
     },
+    process,
 };
 
 use tokio::{
@@ -56,6 +57,16 @@ impl AsyncSendFd for UnixStream {
                 Err(ref e) if e.kind() == ErrorKind::WouldBlock => {
                     continue;
                 }
+                Ok(_) => {
+                    // Try to close the FD if sent into another process
+                    if let Some(pid) = self.peer_cred().ok().and_then(|creds| creds.pid()) {
+                        if pid as u32 != process::id() {
+                            nix::unistd::close(fd)?;
+                        }
+                    }
+
+                    return Ok(());
+                }
                 r => return r,
             }
         }