Struct ListenInit

pub struct ListenInit<F> {
    pub listen: ListenFd,
    pub file: Option<F>,
    pub target: c_int,
    /* private fields */
}

A ListenFd enriched with a relevant file descriptor for passing to a child process.

This either captures one of the file descriptors passed, or initialized a new owning file descriptor, generally a file. It also computes the target file descriptor number. That is, if the file was captured by finding its name in the LISTN_FDNAMES array then it is computed and in-bounds of the passed array. If the file was not captured, it is added to the listen information and its new hypothetical descriptor is stored in target.

Fields

listen: ListenFd

The originally, potentially modified, passed ListenFd.

file: Option<F>

Owns the file if it had to be constructed due to not being found.

target: c_int

The file descriptor the file would have in childs (or the next restart if registered).

See struct description.

Implementations

impl<F> ListenInit<F>

pub fn named_or_try_create<R>( this: Option<ListenFd>, fd_name: &str, with: impl FnOnce() -> Result<F, R>, ) -> Result<Self, R>

Derive a new ListenFd setup, finds or adds a file descriptor.

pub fn maybe_notify(&self, notify: NotifyFd, fd_name: &str) -> Result<(), Error>

where F: AsRawFd,

Available on crate feature std only.

Notify systemd, if the file descriptor was not present.

pub unsafe fn wrap_proc(&self, proc: &mut Command)

where F: AsRawFd,

Available on crate feature std only.

Modify a command such that it copies the file descriptors at the appropriate location.

Safety

This function is unsafe, since the caller must prove that copying the file descriptors is okay.