NAME

Reflex::Signal - receive callbacks when signals arrive

VERSION

version 0.071

SYNOPSIS

eg/eg-39-signals.pl

        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.");
        }

DESCRIPTION

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 Reflex::Role::SigCatcher. That role's documentation contains important details that won't be covered here.

Reflex::Signal is not suitable for SIGCHLD use. The specialized Reflex::PidReaper class is used for that, and it will automatically wait() for processes and return their exit statuses.

Public Attributes

signal

Reflex:Signal's signal attribute defines the name of the signal to catch. Names are as those in %SIG, namely with the leading "SIG" scraped off.

active

The 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.

Public Methods

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.

stop

The stop() method stops and finalizes the signal catcher. It's automatically called at DEMOLISH time, just in case it hasn't already been.

pause

pause() pauses the signal catcher without finalizing it. This is a lighter-weight, non-final version of stop().

resume

resume() resumes a paused signal catcher without re-initializing it. This is a lighter-weight, non-initial version of start().

Callbacks

on_signal

The on_signal() callback notifies the user when the watched signal has been caught. It includes no parameters of note.

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.

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 Reflex::Collection.

Public Events

Reflex::Stream emits stream-related events, naturally.

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 "on_closed" for more details.

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 "on_data" for more details.

error

Reflex::Stream emits "error" when any of a number of calls fails.

See "on_error" for more details.

EXAMPLES

eg/EchoStream.pm in the distribution is the same EchoStream that appears in the SYNOPSIS.

eg/eg-38-promise-client.pl shows a lengthy inline usage of Reflex::Stream and a few other classes.

SEE ALSO

Reflex Reflex::Role::SigCatcher Reflex::Role::PID Reflex::PidReaper

"ACKNOWLEDGEMENTS" in Reflex "ASSISTANCE" in Reflex "AUTHORS" in Reflex "BUGS" in Reflex "BUGS" in Reflex "CONTRIBUTORS" in Reflex "COPYRIGHT" in Reflex "LICENSE" in Reflex "TODO" in Reflex

cpanm Reflex

perl -MCPAN -e shell
install Reflex