subreaper

Documentation

Overview

Package subreaper provides a portable wrapper around the "subreaper" / orphan-cleanup primitive on each supported OS:

• Linux: prctl(PR_SET_CHILD_SUBREAPER) + SIGCHLD reaping
• FreeBSD: procctl(PROC_REAP_ACQUIRE) + SIGCHLD reaping
• macOS: no-op (orphans reparent to launchd)
• Windows: kill-on-close Job Object; orphans die when this process exits and the OS releases the job handle

A typical lifecycle is:

if err := subreaper.Setup(); err != nil { ... }
go subreaper.Reap(ctx)

Index

• func Reap(ctx context.Context)
• func Setup() error

Functions

func Reap

func Reap(ctx context.Context)

Reap collects zombie child processes for the lifetime of ctx. It listens for SIGCHLD and drains all finished children on each tick. When run after Setup it also reaps descendants reparented to us via subreaper / procctl, keeping the process table clean.

func Setup

func Setup() error

Setup makes the current process the "child subreaper" so that double-forked grandchildren are reparented to us instead of pid 1. Combined with Reap this keeps the process table clean.