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package Reflex::Signal;
# vim: ts=2 sw=2 noexpandtab
use Moose;
extends 'Reflex::Base';
use Reflex::Callbacks qw(make_emitter);
has signal => (
is => 'ro',
isa => 'Str',
required => 1,
has active => (
is => 'ro',
isa => 'Bool',
default => 1,
with 'Reflex::Role::SigCatcher' => {
att_signal => 'signal',
att_active => 'active',
cb_signal => make_emitter(on_signal => "signal"),
method_start => 'start',
method_stop => 'stop',
method_pause => 'pause',
method_resume => 'resume',
=head1 NAME
Reflex::Signal - receive callbacks when signals arrive
use warnings;
use strict;
use Reflex::Signal;
use Reflex::Callbacks qw(cb_coderef);
use ExampleHelpers qw(eg_say);
eg_say("Process $$ is waiting for SIGUSR1 and SIGUSR2.");
my $usr1 = Reflex::Signal->new(
signal => "USR1",
on_signal => cb_coderef { eg_say("Got SIGUSR1.") },
my $usr2 = Reflex::Signal->new( signal => "USR2" );
while ($usr2->next()) {
eg_say("Got SIGUSR2.");
Reflex::Signal waits for signals from the operating system. It
may invoke callback functions and/or be used as a promise of new
signals depending on the application's needs.
Reflex::Signal is almost entirely implemented in
That role's documentation contains important details that won't be
covered here.
Reflex::Signal is not suitable for SIGCHLD use. The specialized
Reflex::PID class is used for that, and it will automatically wait()
for processes and return their exit statuses.
=head2 Public Attributes
=head3 signal
Reflex:Signal's C<signal> attribute defines the name of the signal
to catch. Names are as those in %SIG, namely with the leading "SIG"
scraped off.
=head3 active
The C<active> attribute controls whether the signal catcher will be
started in an actively catching state. It defaults to true; set it to
false if you'd like to activate the signal catcher later.
=head2 Public Methods
=head3 start
Reflex::Signal's start() method may be used to initialize signal
catchers and start them watching for signals. start() will be called
automatically if the signal catcher is started in the active state,
which it is by default.
Signal catchers may not be stopped, paused or resumed until they have
been started.
=head3 stop
The stop() method stops and finalizes the signal catcher. It's
automatically called at DEMOLISH time, just in case it hasn't already
=head3 pause
pause() pauses the signal catcher without finalizing it. This is a
lighter-weight, non-final version of stop().
=head3 resume
resume() resumes a paused signal catcher without re-initializing it.
This is a lighter-weight, non-initial version of start().
=head2 Callbacks
=head3 on_signal
The on_signal() callback notifies the user when the watched signal has
been caught. It includes no parameters of note.
=head3 on_data
on_data() will be called whenever Reflex::Stream receives data. It
will include one named parameter in $_[1], "data", containing raw
octets received from the stream.
sub on_data {
my ($self, $param) = @_;
print "Got data: $param->{data}\n";
The default on_data() callback will emit a "data" event.
=head3 on_error
on_error() will be called if an error occurs reading from or writing
to the stream's handle. Its parameters are the usual for Reflex:
sub on_error {
my ($self, $param) = @_;
print "$param->{errfun} error $param->{errnum}: $param->{errstr}\n";
The default on_error() callback will emit a "error" event.
It will also call stopped().
When overriding this callback, please be sure to call stopped(), which
is provided by Reflex::Role::Collectible. Calling stopped() is vital
for collectible objects to be released from memory when managed by
=head2 Public Events
Reflex::Stream emits stream-related events, naturally.
=head3 closed
The "closed" event indicates that the stream is closed. This is most
often caused by the remote end of a socket closing their connection.
See L</on_closed> for more details.
=head3 data
The "data" event is emitted when a stream produces data to work with.
It includes a single parameter, also "data", containing the raw octets
read from the handle.
See L</on_data> for more details.
=head3 error
Reflex::Stream emits "error" when any of a number of calls fails.
See L</on_error> for more details.
eg/ in the distribution is the same EchoStream that
appears in the SYNOPSIS.
eg/ shows a lengthy inline usage of
Reflex::Stream and a few other classes.
=head1 SEE ALSO
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