Struct Process 

pub(crate) struct Process {
    pid: Pid,
    pidfd: Option<OwnedFd>,
}

A child process of the server, which can be signalled without hitting another process that reused its PID.

Fields

pid: Pid

pidfd: Option<OwnedFd>

Keeps referring to the process after it got reaped, unlike the PID. None if the kernel does not support pidfds.

Implementations

impl Process

pub(crate) fn open(pid: Pid) -> Self

Refer to a child which was not reaped yet, so the PID is still its own.

pub(crate) fn child(pid: Pid) -> Self

Refer to a child by its PID alone, which gets checked to still belong to an unreaped child of the server before every signal.

pub(crate) fn pid(&self) -> Pid

The PID of the process.

pub(crate) fn signal(&self, signal: impl Into<Option<Signal>>) -> Result<()>

Signal the process, none only checks that it still exists. Its PID gets reused once something took its exit status, the pidfd still refers to the exited process then and the signal fails with ESRCH instead of hitting another process.

pub(crate) fn signal_group(&self, signal: Signal) -> Result<()>

Signal the process group of the process and the process itself, once it was checked to be unreaped, see REAP_LOCK. The group only gets signalled if signals_group allows it.

A process which got reaped already may have led a group which still has members, like the init of a container without a PID namespace whose children hold the pipes. They got reparented to this server, the subreaper, so the group gets signalled as long as one of them is an unreaped child of the server, which keeps the group ID in use.

fn signal_remaining_group( &self, signal: Signal, own_pgid: Option<Pid>, e: Errno, ) -> Result<()>

Signal the remaining group of a process which is gone, if it still has a member which keeps its ID in use, fail with e otherwise. Not while another process has the PID: the group of a leader which got reaped keeps the ID from getting reused, but once that group is gone as well, a process which reused the PID may lead a group of its own under it.

fn signal_unlocked(&self, signal: Option<Signal>) -> Result<()>

Trait Implementations

impl Debug for Process

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.