Question

I am trying to figure out Event Loops in Perl?

Currently my program does something like this:

    while(my $event = wait_for_event()){
        handle_event($event);
        try_to_do_something();
    }

where wait_for_event is blocking.

I am trying to figure out if I can use EV, or AnyEvent(AE), or something else to add another event watcher.

for example, I want to be able to call try_to_do_something() every 2 seconds, but am currently stuck putting it into the event loop.

Also, I would like to add some form of interaction with the program, possibly through sockets(another watcher).

Thanks

Answer 1

Maybe you are trying to do something like this?

use AnyEvent;
use AnyEvent::Filesys::Notify;

sub try_to_do_something { say "every two seconds" }
sub handle_event { say $_->path." ".$_->type for @_ }

my $n = AnyEvent::Filesys::Notify->new(
    dirs => ['/tmp'],
    interval => 0.5,
    filter => sub { 1 },
    cb => sub { handle_event(@_) },
);
my $w = AE::timer 0, 2, sub {try_to_do_something};

AnyEvent->condvar->recv;

This snippet with AnyEvent and AnyEvent::Filesys::Notify is just one way to do it. Basically it’s almost always the same way, regardless of your framework: Setup your watchers with your callbacks and enter your “mainloop”.