#NAME

Mojo::Reactor - Low-level event reactor base class

#SYNOPSIS

package Mojo::Reactor::MyEventLoop;
use Mojo::Base 'Mojo::Reactor';

sub again      {...}
sub io         {...}
sub is_running {...}
sub next_tick  {...}
sub one_tick   {...}
sub recurring  {...}
sub remove     {...}
sub reset      {...}
sub start      {...}
sub stop       {...}
sub timer      {...}
sub watch      {...}

#DESCRIPTION

Mojo::Reactor is an abstract base class for low-level event reactors, like Mojo::Reactor::EV and Mojo::Reactor::Poll.

#EVENTS

Mojo::Reactor inherits all events from Mojo::EventEmitter and can emit the following new ones.

#error

$reactor->on(error => sub ($reactor, $err) {...});

Emitted for exceptions caught in callbacks, fatal if unhandled. Note that if this event is unhandled or fails it might kill your program, so you need to be careful.

$reactor->on(error => sub ($reactor, $err) { say "Something very bad happened: $err" });

#METHODS

Mojo::Reactor inherits all methods from Mojo::EventEmitter and implements the following new ones.

#again

$reactor->again($id);
$reactor->again($id, 0.5);

Restart timer and optionally change the invocation time. Meant to be overloaded in a subclass. Note that this method requires an active timer.

#detect

my $class = Mojo::Reactor->detect;

Detect and load the best reactor implementation available, will try the value of the MOJO_REACTOR environment variable, Mojo::Reactor::EV or Mojo::Reactor::Poll.

# Instantiate best reactor implementation available
my $reactor = Mojo::Reactor->detect->new;

#io

$reactor = $reactor->io($handle => sub {...});

Watch handle for I/O events, invoking the callback whenever handle becomes readable or writable. Meant to be overloaded in a subclass.

# Callback will be executed twice if handle becomes readable and writable
$reactor->io($handle => sub ($reactor, $writable) {
  say $writable ? 'Handle is writable' : 'Handle is readable';
});

#is_running

my $bool = $reactor->is_running;

Check if reactor is running. Meant to be overloaded in a subclass.

#next_tick

my $undef = $reactor->next_tick(sub {...});

Execute callback as soon as possible, but not before returning or other callbacks that have been registered with this method, always returns undef. Meant to be overloaded in a subclass.

#one_tick

$reactor->one_tick;

Run reactor until an event occurs. Note that this method can recurse back into the reactor, so you need to be careful. Meant to be overloaded in a subclass.

# Don't block longer than 0.5 seconds
my $id = $reactor->timer(0.5 => sub {});
$reactor->one_tick;
$reactor->remove($id);

#recurring

my $id = $reactor->recurring(0.25 => sub {...});

Create a new recurring timer, invoking the callback repeatedly after a given amount of time in seconds. Meant to be overloaded in a subclass.

#remove

my $bool = $reactor->remove($handle);
my $bool = $reactor->remove($id);

Remove handle or timer. Meant to be overloaded in a subclass.

#reset

$reactor->reset;

Remove all handles and timers. Meant to be overloaded in a subclass.

#start

$reactor->start;

Start watching for I/O and timer events, this will block until "stop" is called. Note that some reactors stop automatically if there are no events being watched anymore. Meant to be overloaded in a subclass.

# Start reactor only if it is not running already
$reactor->start unless $reactor->is_running;

#stop

$reactor->stop;

Stop watching for I/O and timer events. Meant to be overloaded in a subclass.

#timer

my $id = $reactor->timer(0.5 => sub {...});

Create a new timer, invoking the callback after a given amount of time in seconds. Meant to be overloaded in a subclass.

#watch

$reactor = $reactor->watch($handle, $readable, $writable);

Change I/O events to watch handle for with true and false values. Meant to be overloaded in a subclass. Note that this method requires an active I/O watcher.

# Watch only for readable events
$reactor->watch($handle, 1, 0);

# Watch only for writable events
$reactor->watch($handle, 0, 1);

# Watch for readable and writable events
$reactor->watch($handle, 1, 1);

# Pause watching for events
$reactor->watch($handle, 0, 0);