#!/usr/bin/perl
#
# Create parent <==> child message relationship with socketpair()
# Then thread the parent and try to contact the child

use threads;
use IPC::MPS;
use warnings;
use v5.14;

my $child;
INIT {
    $child = spawn {
        receive {
            msg hi => sub {
                my ($from) = @_;
                say "$$ - Hi there!";
                snd( $from, 'hi', $$ );
            };
        };
    };
    receive { quit; };
    say "My child vpid: $child";
}

sub say_hi {
    my $ans = snd_wt( $child, 'hi');
    say "$$ - My child $ans said hi";
};

say 'Single-threaded execution';
say_hi;

say 'Threaded execution';
my $thr = threads->create( \&say_hi );
$thr->join;

__END__

My child vpid: 18275192
Single-threaded execution
7533 - Hi there!
7532 - My child 7533 said hi
Threaded execution
<_HANGS_HERE_>