Linux::Event::Fork Examples

These scripts are small, focused demos of Linux::Event::Fork features.

Quick start

From the distribution root:

perl -Ilib examples/12_fork_exit_object.pl

Most examples use Linux::Event + Linux::Event::Fork like this:

use Linux::Event;
use Linux::Event::Fork;

my $loop = Linux::Event->new;

# Optional: configure bounded parallelism at runtime
my $fork = $loop->fork_helper(max_children => 4);

$loop->fork(cmd => [ ... ]);
$loop->run;

Canonical configuration style

This distribution intentionally uses runtime configuration:

my $fork = $loop->fork_helper(max_children => 4);

A previous compile-time idiom (use Linux::Event::Fork max_children => ...;) is removed.

Example index

Core concepts

• 12_fork_exit_object.pl
  Demonstrates the Exit object and streaming stdout/stderr capture.

• 13_fork_child_callback.pl
  Demonstrates child => sub { ... } (run code in the child) and why exec is recommended.

• 14_fork_stdin_streaming.pl
  Demonstrates streaming to the child’s stdin (nonblocking writes) and reading responses.

• 22_timeout_kill.pl
  Demonstrates soft timeouts (timeout callback + SIGTERM cleanup).

Pool / queue policy

• 20_bounded_parallelism_with_drain.pl
  Shows max_children bounded parallelism, queueing, and drain().

• 23_cancel_queued_by_tag.pl
  Shows cancel_queued() (only queued requests) and drain() to stop when fully idle.

Practical “real world” demos

• 21_web_fetch_pool.pl
  A pool that runs many independent fetch tasks concurrently (using cmd => [...]). This demonstrates how to build a tiny work-queue without a framework.

Notes

• 25_chunking_notes.pl
  Notes about streaming callbacks: you receive chunks, not “lines”, and should buffer if you need framing.

Tips for users

• cmd => [...] is the simplest and fastest form: it forks, wires FDs, then execs.
• Use tag => ... to label work (for logs and for canceling queued requests).
• cancel_queued() does not affect running children.
• drain(on_done => sub { ... }) fires when both:
  • no children are running, and
  • the queue is empty.