process: add {ChildStd*}::into_owned_{fd, handle} (#5899)

tokio/src/doc/os.rs

@@ -11,6 +11,9 @@ pub mod windows {
         /// See [std::os::windows::io::RawHandle](https://doc.rust-lang.org/std/os/windows/io/type.RawHandle.html)
         pub type RawHandle = crate::doc::NotDefinedHere;
 
+        /// See [std::os::windows::io::OwnedHandle](https://doc.rust-lang.org/std/os/windows/io/struct.OwnedHandle.html)
+        pub type OwnedHandle = crate::doc::NotDefinedHere;
+
         /// See [std::os::windows::io::AsRawHandle](https://doc.rust-lang.org/std/os/windows/io/trait.AsRawHandle.html)
         pub trait AsRawHandle {
             /// See [std::os::windows::io::AsRawHandle::as_raw_handle](https://doc.rust-lang.org/std/os/windows/io/trait.AsRawHandle.html#tymethod.as_raw_handle)

tokio/src/process/mod.rs

@@ -259,7 +259,7 @@ use std::os::unix::process::CommandExt;
 use std::os::windows::process::CommandExt;
 
 cfg_windows! {
-    use crate::os::windows::io::{AsRawHandle, RawHandle, AsHandle, BorrowedHandle};
+    use crate::os::windows::io::{AsRawHandle, RawHandle};
 }
 
 /// This structure mimics the API of [`std::process::Command`] found in the standard library, but
@@ -1447,84 +1447,100 @@ impl TryInto<Stdio> for ChildStderr {
 }
 
 #[cfg(unix)]
+#[cfg_attr(docsrs, doc(cfg(unix)))]
 mod sys {
-    use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, RawFd};
+    use std::{
+        io,
+        os::unix::io::{AsFd, AsRawFd, BorrowedFd, OwnedFd, RawFd},
+    };
 
     use super::{ChildStderr, ChildStdin, ChildStdout};
 
-    impl AsRawFd for ChildStdin {
-        fn as_raw_fd(&self) -> RawFd {
-            self.inner.as_raw_fd()
-        }
+    macro_rules! impl_traits {
+        ($type:ty) => {
+            impl $type {
+                /// Convert into [`OwnedFd`].
+                pub fn into_owned_fd(self) -> io::Result<OwnedFd> {
+                    self.inner.into_owned_fd()
+                }
+            }
+
+            impl AsRawFd for $type {
+                fn as_raw_fd(&self) -> RawFd {
+                    self.inner.as_raw_fd()
+                }
+            }
+
+            impl AsFd for $type {
+                fn as_fd(&self) -> BorrowedFd<'_> {
+                    unsafe { BorrowedFd::borrow_raw(self.as_raw_fd()) }
+                }
+            }
+        };
     }
 
-    impl AsFd for ChildStdin {
-        fn as_fd(&self) -> BorrowedFd<'_> {
-            unsafe { BorrowedFd::borrow_raw(self.as_raw_fd()) }
-        }
-    }
-
-    impl AsRawFd for ChildStdout {
-        fn as_raw_fd(&self) -> RawFd {
-            self.inner.as_raw_fd()
-        }
-    }
-
-    impl AsFd for ChildStdout {
-        fn as_fd(&self) -> BorrowedFd<'_> {
-            unsafe { BorrowedFd::borrow_raw(self.as_raw_fd()) }
-        }
-    }
-
-    impl AsRawFd for ChildStderr {
-        fn as_raw_fd(&self) -> RawFd {
-            self.inner.as_raw_fd()
-        }
-    }
-
-    impl AsFd for ChildStderr {
-        fn as_fd(&self) -> BorrowedFd<'_> {
-            unsafe { BorrowedFd::borrow_raw(self.as_raw_fd()) }
-        }
-    }
+    impl_traits!(ChildStdin);
+    impl_traits!(ChildStdout);
+    impl_traits!(ChildStderr);
 }
 
-cfg_windows! {
-    impl AsRawHandle for ChildStdin {
-        fn as_raw_handle(&self) -> RawHandle {
-            self.inner.as_raw_handle()
-        }
+#[cfg(any(windows, docsrs))]
+#[cfg_attr(docsrs, doc(cfg(windows)))]
+mod windows {
+    use super::*;
+    use crate::os::windows::io::{AsHandle, AsRawHandle, BorrowedHandle, OwnedHandle, RawHandle};
+
+    #[cfg(not(docsrs))]
+    macro_rules! impl_traits {
+        ($type:ty) => {
+            impl $type {
+                /// Convert into [`OwnedHandle`].
+                pub fn into_owned_handle(self) -> io::Result<OwnedHandle> {
+                    self.inner.into_owned_handle()
+                }
+            }
+
+            impl AsRawHandle for $type {
+                fn as_raw_handle(&self) -> RawHandle {
+                    self.inner.as_raw_handle()
+                }
+            }
+
+            impl AsHandle for $type {
+                fn as_handle(&self) -> BorrowedHandle<'_> {
+                    unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+                }
+            }
+        };
     }
 
-    impl AsHandle for ChildStdin {
-        fn as_handle(&self) -> BorrowedHandle<'_> {
-            unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
-        }
+    #[cfg(docsrs)]
+    macro_rules! impl_traits {
+        ($type:ty) => {
+            impl $type {
+                /// Convert into [`OwnedHandle`].
+                pub fn into_owned_handle(self) -> io::Result<OwnedHandle> {
+                    todo!("For doc generation only")
+                }
+            }
+
+            impl AsRawHandle for $type {
+                fn as_raw_handle(&self) -> RawHandle {
+                    todo!("For doc generation only")
+                }
+            }
+
+            impl AsHandle for $type {
+                fn as_handle(&self) -> BorrowedHandle<'_> {
+                    todo!("For doc generation only")
+                }
+            }
+        };
     }
 
-    impl AsRawHandle for ChildStdout {
-        fn as_raw_handle(&self) -> RawHandle {
-            self.inner.as_raw_handle()
-        }
-    }
-
-    impl AsHandle for ChildStdout {
-        fn as_handle(&self) -> BorrowedHandle<'_> {
-            unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
-        }
-    }
-
-    impl AsRawHandle for ChildStderr {
-        fn as_raw_handle(&self) -> RawHandle {
-            self.inner.as_raw_handle()
-        }
-    }
-
-    impl AsHandle for ChildStderr {
-        fn as_handle(&self) -> BorrowedHandle<'_> {
-            unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
-        }
-    }
+    impl_traits!(ChildStdin);
+    impl_traits!(ChildStdout);
+    impl_traits!(ChildStderr);
 }
 
 #[cfg(all(test, not(loom)))]

tokio/src/process/unix/mod.rs

@@ -39,7 +39,7 @@ use std::fmt;
 use std::fs::File;
 use std::future::Future;
 use std::io;
-use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, RawFd};
+use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
 use std::pin::Pin;
 use std::process::{Child as StdChild, ExitStatus, Stdio};
 use std::task::Context;
@@ -200,7 +200,7 @@ impl AsFd for Pipe {
     }
 }
 
-pub(crate) fn convert_to_stdio(io: ChildStdio) -> io::Result<Stdio> {
+fn convert_to_blocking_file(io: ChildStdio) -> io::Result<File> {
     let mut fd = io.inner.into_inner()?.fd;
 
     // Ensure that the fd to be inherited is set to *blocking* mode, as this
@@ -209,7 +209,11 @@ pub(crate) fn convert_to_stdio(io: ChildStdio) -> io::Result<Stdio> {
     // change it to nonblocking mode.
     set_nonblocking(&mut fd, false)?;
 
-    Ok(Stdio::from(fd))
+    Ok(fd)
+}
+
+pub(crate) fn convert_to_stdio(io: ChildStdio) -> io::Result<Stdio> {
+    convert_to_blocking_file(io).map(Stdio::from)
 }
 
 impl Source for Pipe {
@@ -240,6 +244,12 @@ pub(crate) struct ChildStdio {
     inner: PollEvented<Pipe>,
 }
 
+impl ChildStdio {
+    pub(super) fn into_owned_fd(self) -> io::Result<OwnedFd> {
+        convert_to_blocking_file(self).map(OwnedFd::from)
+    }
+}
+
 impl fmt::Debug for ChildStdio {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.inner.fmt(fmt)

tokio/src/process/windows.rs

@@ -24,7 +24,7 @@ use std::fmt;
 use std::fs::File as StdFile;
 use std::future::Future;
 use std::io;
-use std::os::windows::prelude::{AsRawHandle, IntoRawHandle, RawHandle};
+use std::os::windows::prelude::{AsRawHandle, IntoRawHandle, OwnedHandle, RawHandle};
 use std::pin::Pin;
 use std::process::Stdio;
 use std::process::{Child as StdChild, Command as StdCommand, ExitStatus};
@@ -195,6 +195,12 @@ pub(crate) struct ChildStdio {
     io: Blocking<ArcFile>,
 }
 
+impl ChildStdio {
+    pub(super) fn into_owned_handle(self) -> io::Result<OwnedHandle> {
+        convert_to_file(self).map(OwnedHandle::from)
+    }
+}
+
 impl AsRawHandle for ChildStdio {
     fn as_raw_handle(&self) -> RawHandle {
         self.raw.as_raw_handle()
@@ -240,13 +246,15 @@ where
     Ok(ChildStdio { raw, io })
 }
 
-pub(crate) fn convert_to_stdio(child_stdio: ChildStdio) -> io::Result<Stdio> {
+fn convert_to_file(child_stdio: ChildStdio) -> io::Result<StdFile> {
     let ChildStdio { raw, io } = child_stdio;
     drop(io); // Try to drop the Arc count here
 
-    Arc::try_unwrap(raw)
-        .or_else(|raw| duplicate_handle(&*raw))
-        .map(Stdio::from)
+    Arc::try_unwrap(raw).or_else(|raw| duplicate_handle(&*raw))
+}
+
+pub(crate) fn convert_to_stdio(child_stdio: ChildStdio) -> io::Result<Stdio> {
+    convert_to_file(child_stdio).map(Stdio::from)
 }
 
 fn duplicate_handle<T: AsRawHandle>(io: &T) -> io::Result<StdFile> {