Parallel::Pipes(3pm) User Contributed Perl Documentation Parallel::Pipes(3pm)

# [NAME](#NAME)

Parallel::Pipes - parallel processing using [pipe(2)](/man/os/perl-parallel-pipes/pipe.2) for communication and synchronization

# [SYNOPSIS](#SYNOPSIS)

```
  use Parallel::Pipes;
  my $pipes = Parallel::Pipes->new(5, sub ($task) {
    # this is a worker code
    my $result = do_work($task);
    return $result;
  });
  my $queue = Your::TaskQueue->new;
  # wrap Your::TaskQueue->get
  my $get; $get = sub ($queue) {
    if (my @task = $queue->get) {
      return @task;
    }
    if (my @written = $pipes->is_written) {
      my @ready = $pipes->is_ready(@written);
      $queue->register($_->read) for @ready;
      return $queue->$get;
    } else {
      return;
    }
  };
  while (my @task = $queue->$get) {
    my @ready = $pipes->is_ready;
    $queue->register($_->read) for grep $_->is_written, @ready;
    my $min = List::Util::min($#task, $#ready);
    for my $i (0..$min) {
      # write tasks to pipes which are ready
      $ready[$i]->write($task[$i]);
    }
  }
  $pipes->close;
```

# [DESCRIPTION](#DESCRIPTION)

**NOTE**: Parallel::Pipes provides low-level interfaces. If you are interested in using Parallel::Pipes, you may want to look at Parallel::Pipes::App instead, which provides more friendly interfaces.

Parallel processing is essential, but it is also difficult:

[How can we synchronize our workers?](#How)

More precisely, how to detect our workers are ready or finished.

[How can we communicate with our workers?](#How~2)

More precisely, how to collect results of tasks.

Parallel::Pipes tries to solve these problems with [pipe(2)](/man/os/perl-parallel-pipes/pipe.2) and [select(2)](/man/os/perl-parallel-pipes/select.2).

App::cpm, a fast CPAN module installer, uses Parallel::Pipes. Please look at App::cpm <https://github.com/skaji/cpm/blob/master/lib/App/cpm/CLI.pm> or eg directory <https://github.com/skaji/Parallel-Pipes/tree/main/eg> for real world usages.

# [ARTIFACT ATTESTATIONS](#ARTIFACT_ATTESTATIONS)

GitHub Artifact Attestations are generated for release tarballs uploaded to CPAN. If you care about provenance for the uploaded tarballs, see:

<https://github.com/skaji/Parallel-Pipes/attestations>

# [COPYRIGHT AND LICENSE](#COPYRIGHT_AND_LICENSE)

Copyright 2016 Shoichi Kaji <skaji@cpan.org>

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

2026-06-18 perl v5.42.2

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Document: Parallel::Pipes(3pm) from perl-parallel-pipes 1.0.0-r1 (Chainguard OS)
Source: https://github.com/skaji/Parallel-Pipes