Good day all,

this is just another useless waste of time for fun and perhaps learning.

I spawn 4 processes but ps shows 6. But it should be 5, right?

#!/usr/bin/env perl

# "When I first started hobo'in,
# I took a freight train to be my friend"
# -John Lee Hooker
# https://www.youtube.com/watch?v=1kQlRQRGdfQ

use strict;
use warnings;
use MCE::Hobo;
use MCE::Shared;
use feature qw(say);
# use Sereal ();
use MCE::Mutex;

say "procs at start:\n", procs();

our $mutex = MCE::Mutex->new;

# say $mutex->impl();
my $result = MCE::Shared->array();
my $foo    = MCE::Hobo->create( \&task, "foo" );
my $bar    = MCE::Hobo->create( \&task, "bar" );
my $nose   = MCE::Hobo->create( \&task, "nose" );
my $cuke   = MCE::Hobo->create( \&task, "cuke" );
my @hobos  = MCE::Hobo->list();

say "spawned hobos:";

for (@hobos) {
    if ( $_->is_running() ) {
        say 'pid: ', $_->pid();
    }
}

say 'pending hobos: ', MCE::Hobo->pending();
say "procs at pending:\n", procs();

$_->join() for @hobos;

say "procs after join:\n", procs();
say "result:";
say for @$result;

sub task {
    our $mutex;
    $mutex->lock;
    $result->push(shift);
    $mutex->unlock;
}

sub procs {
    my $procs = qx(ps aux | grep [p]erl);
    $procs =~ s/ //g;
    chomp $procs;
    $procs;
}
__END__

karls-mac-mini:MyAdaModule karl$ ./hobo.pl
procs at start:
karl254417,30,124421128816s000S+6:03pm0:00.07perl./hobo.pl
spawned hobos:
pid: 2549
pid: 2550
pid: 2551
pid: 2552
pending hobos: 4
procs at pending:
karl254417,30,124421129264s000S+6:03pm0:00.08perl./hobo.pl
karl25520,00,000s000Z+6:03pm0:00.00(perl)
karl25510,00,000s000Z+6:03pm0:00.00(perl)
karl25500,00,000s000Z+6:03pm0:00.00(perl)
karl25490,00,000s000Z+6:03pm0:00.00(perl)
karl25480,00,024421123116s000S+6:03pm0:00.00perl./hobo.pl
procs after join:
karl254417,30,124421129264s000S+6:03pm0:00.08perl./hobo.pl
karl25480,00,024421123136s000S+6:03pm0:00.00perl./hobo.pl
result:
foo
bar
nose
cuke
[download]

Update: Added more debugging output

Thanks for any hint and sorry if i missed something essential.

Update 2:

#!/usr/bin/env perl

use strict;
use warnings;

use threads;
use threads::shared;
use MCE::Hobo;
use MCE::Shared;
use feature qw(say);

say q(procs at start: ), procs();

my $result = MCE::Shared->array();

for (qw(foo bar nose cuke)) {
    MCE::Hobo->create( \&task, $_ );
}

my @hobos = MCE::Hobo->list();

say q(spawned hobos:);

for (@hobos) {
    if ( $_->is_running() ) {
        say q(pid: ), $_->pid();
    }
}

say q(pending hobos: ), MCE::Hobo->pending();

say q(procs at pending: ), procs();

$_->join() for @hobos;

say q(procs after join: ), procs();

say q(result:);

say for @$result;

sub task {
    $result->push(shift);
}

sub procs {
    my $procs = grep { /perl/ } qx(ps aux);
}

__END__

karls-mac-mini:monks karl$  ./hobo.pl
procs at start: 1
spawned hobos:
pid: 3835
pid: 3836
pid: 3837
pid: 3838
pending hobos: 4
procs at pending: 5
procs after join: 1
result:
foo
bar
nose
cuke
[download]

Regards, Karl