Sometimes, the use-case calls for processing at the chunk level inside the code block. For example, the worker receives the chunk as a whole.

mce_forchunk
mce_forchunk_f
mce_forchunk_s
[download]

I will use MCE::Loop behind the scene.

The mce_forchunk keywords are working. Sometimes, it's preferably to process at the chunk level. So, here it is.

mce_forchunk

use MCE::Simple -strict, max_workers => 4, init_relay => '';

mce_forchunk (11..19) {
    my ($mce, $chunk_ref, $chunk_id) = @_;
    for my $i (@{ $chunk_ref }) {
        MCE->say($i);
    }
}

mce_forchunk (31..39) {
    for my $i (@{ $_ }) {
        MCE->say($i);
    }
}

mce_forchunk my $chunk (51..59) {
    for my $i (@{ $chunk }) {
        MCE->say($i);
    }
}

mce_forchunk my $chunk (71..79) {
    my $output = "From chunk_id: ".MCE->chunk_id."\n";
    for my $i (@{ $chunk }) {
        $output .= "$i\n";
    }
    MCE::relay {
        # write directly to STDOUT, not involve manager process
        print $output;
    };
}
[download]

Output

15
13
11
16
14
17
12
18
19
33
34
31
39
32
37
35
38
36
51
57
53
52
55
58
54
56
59
From chunk_id: 1
71
72
From chunk_id: 2
73
74
From chunk_id: 3
75
76
From chunk_id: 4
77
78
From chunk_id: 5
79
[download]

Spawn MCE asynchronously

MCE::Simple expands keywords at compile time to parallel code.

use MCE::Simple (
    include => [qw/ -strict -signatures /],
    max_workers => 4, init_relay => '',
);

MCE::Simple->init(
    on_finish => sub ( $pid, $exit, $ident, $signal, $error, @ret ) {
        say "MCE job ** $ident ** completed; status $exit.";
        print join('', @ret);
    },
);

spawn "foo", sub {
    my @results;
    MCE::Simple->init(gather => \@results);

    mce_forchunk my $chunk (91..99) {
        my $output = "From chunk_id: ".MCE->chunk_id."\n";
        for my $i (@{ $chunk }) {
            $output .= "$i\n";
        }
        MCE::relay {
            MCE->gather($output);
        };
    }

    @results;
};

# do something else

sync;
[download]

Output

MCE job ** foo ** completed; status 0.
From chunk_id: 1
91
92
From chunk_id: 2
93
94
From chunk_id: 3
95
96
From chunk_id: 4
97
98
From chunk_id: 5
99
[download]

Or using MCE::Loop instead. One can have MCE::Loop gather orderly via MCE::relay.

use MCE::Simple (
    include => [qw/ -strict -signatures -mce_loop /],
    max_workers => 4, init_relay => '',
);

MCE::Simple->init(
    on_finish => sub ( $pid, $exit, $ident, $signal, $error, @ret ) {
        say "MCE job ** $ident ** completed; status $exit.";
        print join('', @ret);
    },
);

spawn "foo", sub {
    my @results = mce_loop {
        my $output = "From chunk_id: ".MCE->chunk_id."\n";
        for my $i (@{ $_ }) {
            $output .= "$i\n";
        }
        MCE::relay {
            MCE->gather($output);
        };
    } 91..99;
};

# do something else

sync;
[download]

Thank you, PerlMonks. I was able to think out loud. The demonstrations work flawlessly.