NAME

UV::Async - Async notification handles in libuv

SYNOPSIS

  #!/usr/bin/env perl
  use strict;
  use warnings;

  use UV;

  # A new handle will be initialized against the default loop
  my $async = UV::Async->new();

  # Use a different loop
  my $loop = UV::Loop->new(); # non-default loop
  my $async = UV::Async->new(
    loop => $loop,
    on_close => sub {say "close!"},
    on_async => sub {say "async!"},
  );

  # setup the async callback:
  $async->on(async => sub {say "We're IDLING!!!"});

  # trigger the async callback
  $async->send();

DESCRIPTION

This module provides an interface to libuv's async handle.

Async handles store a callback to be invoked when requested by some possibly-asynchronous activity, such as in a signal handler or OS-level thread. They are generally not that useful from Perl code, but are included for completeness in case a situation arises for them.

EVENTS

UV::Async inherits all events from UV::Handle and also makes the following extra events available.

async

    $handle->on(async => sub { my $invocant = shift; say "We were invoked!"});
    my $count = 0;
    $handle->on("async", sub {
        my $invocant = shift; # the handle instance this event fired on
        if (++$count > 2) {
            say "We were invoked twice. stopping!";
            $invocant->stop();
        }
    });

When the event loop runs and the async is invoked, this event will be fired.

METHODS

UV::Async inherits all methods from UV::Handle and also makes the following extra methods available.

new

    my $async = UV::Async->new();
    # Or tell it what loop to initialize against
    my $async = UV::Async->new(
        loop => $loop,
        on_close => sub {say "close!"},
        on_async => sub {say "async!"},
    );

This constructor method creates a new UV::Async object and initializes the handle with the given UV::Loop. If no UV::Loop is provided, then the "default_loop" in UV::Loop is assumed.

send

    $async->send();

The send method schedules the event loop to wake up and invoke the async callback.

AUTHOR

Paul Evans <leonerd@leonerd.org.uk>

LICENSE

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