Struct PostSpawnAction 

pub struct PostSpawnAction { /* private fields */ }

Action that must be applied to a spawned child process after Command::spawn returns, from the parent process.

This exists because moving a child into a cgroup used to be done from a pre_exec closure, which runs in the forked child between fork and exec. That context is effectively single-threaded and inherits locks held by other threads of the parent at fork time — any allocation (format!, PathBuf::join, fs::write) can deadlock on a malloc mutex that was held by another thread at fork time. Instead, we record what needs to happen and do the work from the parent once the child has a PID.

Implementations

impl PostSpawnAction

pub fn apply_to_child(&self, _child_pid: u32)

Apply the recorded action to a just-spawned child PID.

Safe to call from the parent — unlike the old pre_exec variant, this runs with the full runtime available (no fork-safety constraints). Errors are logged but not returned: best-effort, because the process is already running and we don’t want to kill it just because cgroup assignment failed.

Trait Implementations

impl Debug for PostSpawnAction

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

Formats the value using the given formatter.

impl Default for PostSpawnAction

fn default() -> PostSpawnAction

Returns the “default value” for a type.