From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- library/std/src/os/linux/process.rs | 165 ++++++++++++++++++++++++++++++++++++ 1 file changed, 165 insertions(+) create mode 100644 library/std/src/os/linux/process.rs (limited to 'library/std/src/os/linux/process.rs') diff --git a/library/std/src/os/linux/process.rs b/library/std/src/os/linux/process.rs new file mode 100644 index 000000000..540363c03 --- /dev/null +++ b/library/std/src/os/linux/process.rs @@ -0,0 +1,165 @@ +//! Linux-specific extensions to primitives in the [`std::process`] module. +//! +//! [`std::process`]: crate::process + +#![unstable(feature = "linux_pidfd", issue = "82971")] + +use crate::io::Result; +use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd}; +use crate::process; +use crate::sealed::Sealed; +#[cfg(not(doc))] +use crate::sys::fd::FileDesc; +use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner}; + +#[cfg(doc)] +struct FileDesc; + +/// This type represents a file descriptor that refers to a process. +/// +/// A `PidFd` can be obtained by setting the corresponding option on [`Command`] +/// with [`create_pidfd`]. Subsequently, the created pidfd can be retrieved +/// from the [`Child`] by calling [`pidfd`] or [`take_pidfd`]. +/// +/// Example: +/// ```no_run +/// #![feature(linux_pidfd)] +/// use std::os::linux::process::{CommandExt, ChildExt}; +/// use std::process::Command; +/// +/// let mut child = Command::new("echo") +/// .create_pidfd(true) +/// .spawn() +/// .expect("Failed to spawn child"); +/// +/// let pidfd = child +/// .take_pidfd() +/// .expect("Failed to retrieve pidfd"); +/// +/// // The file descriptor will be closed when `pidfd` is dropped. +/// ``` +/// Refer to the man page of [`pidfd_open(2)`] for further details. +/// +/// [`Command`]: process::Command +/// [`create_pidfd`]: CommandExt::create_pidfd +/// [`Child`]: process::Child +/// [`pidfd`]: fn@ChildExt::pidfd +/// [`take_pidfd`]: ChildExt::take_pidfd +/// [`pidfd_open(2)`]: https://man7.org/linux/man-pages/man2/pidfd_open.2.html +#[derive(Debug)] +pub struct PidFd { + inner: FileDesc, +} + +impl AsInner for PidFd { + fn as_inner(&self) -> &FileDesc { + &self.inner + } +} + +impl FromInner for PidFd { + fn from_inner(inner: FileDesc) -> PidFd { + PidFd { inner } + } +} + +impl IntoInner for PidFd { + fn into_inner(self) -> FileDesc { + self.inner + } +} + +impl AsRawFd for PidFd { + fn as_raw_fd(&self) -> RawFd { + self.as_inner().as_raw_fd() + } +} + +impl FromRawFd for PidFd { + unsafe fn from_raw_fd(fd: RawFd) -> Self { + Self::from_inner(FileDesc::from_raw_fd(fd)) + } +} + +impl IntoRawFd for PidFd { + fn into_raw_fd(self) -> RawFd { + self.into_inner().into_raw_fd() + } +} + +impl AsFd for PidFd { + fn as_fd(&self) -> BorrowedFd<'_> { + self.as_inner().as_fd() + } +} + +impl From for PidFd { + fn from(fd: OwnedFd) -> Self { + Self::from_inner(FileDesc::from_inner(fd)) + } +} + +impl From for OwnedFd { + fn from(pid_fd: PidFd) -> Self { + pid_fd.into_inner().into_inner() + } +} + +/// Os-specific extensions for [`Child`] +/// +/// [`Child`]: process::Child +pub trait ChildExt: Sealed { + /// Obtains a reference to the [`PidFd`] created for this [`Child`], if available. + /// + /// A pidfd will only be available if its creation was requested with + /// [`create_pidfd`] when the corresponding [`Command`] was created. + /// + /// Even if requested, a pidfd may not be available due to an older + /// version of Linux being in use, or if some other error occurred. + /// + /// [`Command`]: process::Command + /// [`create_pidfd`]: CommandExt::create_pidfd + /// [`Child`]: process::Child + fn pidfd(&self) -> Result<&PidFd>; + + /// Takes ownership of the [`PidFd`] created for this [`Child`], if available. + /// + /// A pidfd will only be available if its creation was requested with + /// [`create_pidfd`] when the corresponding [`Command`] was created. + /// + /// Even if requested, a pidfd may not be available due to an older + /// version of Linux being in use, or if some other error occurred. + /// + /// [`Command`]: process::Command + /// [`create_pidfd`]: CommandExt::create_pidfd + /// [`Child`]: process::Child + fn take_pidfd(&mut self) -> Result; +} + +/// Os-specific extensions for [`Command`] +/// +/// [`Command`]: process::Command +pub trait CommandExt: Sealed { + /// Sets whether a [`PidFd`](struct@PidFd) should be created for the [`Child`] + /// spawned by this [`Command`]. + /// By default, no pidfd will be created. + /// + /// The pidfd can be retrieved from the child with [`pidfd`] or [`take_pidfd`]. + /// + /// A pidfd will only be created if it is possible to do so + /// in a guaranteed race-free manner (e.g. if the `clone3` system call + /// is supported). Otherwise, [`pidfd`] will return an error. + /// + /// [`Command`]: process::Command + /// [`Child`]: process::Child + /// [`pidfd`]: fn@ChildExt::pidfd + /// [`take_pidfd`]: ChildExt::take_pidfd + fn create_pidfd(&mut self, val: bool) -> &mut process::Command; +} + +impl CommandExt for process::Command { + fn create_pidfd(&mut self, val: bool) -> &mut process::Command { + self.as_inner_mut().create_pidfd(val); + self + } +} -- cgit v1.2.3