Update: I've solved the issue. Everything defined/created in the app that is NOT referenced within at least one route goes out of scope when the app is started. If something is referenced within a route even just once, it lives. Even my forking code works now :)

I'm still working on my Dancer2 application, but now I'm at the point where I need it to periodically to something, even without client interaction. Essentially, I want the Dancer2 app to behave like a normal always-running background script while a client browser is not attached.

So, what I need to do is have this app periodically do something without tying up the main application. I wrote a *very* basic async timed event module Async::Event::Interval (yeah, for fun, mostly). It works, and does what I need it to do (the event is a forked process). Here's an example:

use warnings;
use strict;

use Async::Event::Interval;

my $event = Async::Event::Interval->new(
    1, # interval, in seconds
    sub {
        print "event...\n";
    },
);
$event->start;

sleep 1; # wait for first event to fire
print "main is going to sleep...\n";
sleep 5;
print "done\n";

[download]

Output:

event...
main is going to sleep...
event...
event...
event...
event...
event...
done

[download]

I fetch the PID of the event process, and it shows up just dandy as running in the proc list:

$ ps ax | grep 22834
22834 pts/2    S+     0:00 perl t/evt.pl

[download]

However, no matter where it is I create and start the event in a Dancer2 app, it fires after the first interval is expired, but then in the proc list I see:

$ps ax | grep 22732
22732 pts/2    Z+     0:00 [/home/spek/repo] <defunct>

[download]

Can anyone explain what Dancer2 is doing that forces a child process to become defunct, or how I can get around/avoid this problem without having to have a second background app running to do the side-work that is needed? If anyone thinks a different async type software will work, I'll ditch my own, as it was just for playing around anyways.

As a side note, I have no idea why it's showing /home/spek/repo in the proc entry, as my current working dir is ~/repo/app-envui when I start the webapp.

In reply to [SOLVED]: Async timed events with Dancer2 by stevieb

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