use strict;
use warnings;
use feature 'say';
use threads;
use Thread::Queue;
use CAM::PDF;
use File::Find;

my $q = Thread::Queue-> new;

my @gang = map async( sub {
    while ( defined( my $f = $q-> dequeue )) {
        say threads-> tid, ' ', $f;
        my $pdf = CAM::PDF-> new( $f ) or die;
    }
}), 1 .. 2;

find( sub {
    -f and /\.pdf$/i and $q-> enqueue( $File::Find::name )
}, './1' );

$q-> end;
$_-> join for @gang;

__END__

1 ./1/1/106/10627.pdf
2 ./1/1/107/10703.pdf
2 ./1/1/186/18673.pdf
1 ./1/1/209/20946.pdf
2 ./1/1/26/2656.pdf
1 ./1/1/33/3384.pdf
2 ./1/1/57/5742.pdf
1 ./1/1/58/5869.pdf
2 ./1/1/63/6395.pdf
1 ./1/1/70/7099.pdf
1 ./1/1/74/7466.pdf


##</code><code>##

1 ./1/1/106/10627.pdf
2 ./1/1/107/10703.pdf
Thread 2 terminated abnormally: *****Undefined subroutine &Compress::Zlib::Parse
Parameters called at C:/strawberry-perl-5.28.0.1-32bit-PDL/perl/lib/Compress/Zli
b.pm line 366.
1 ./1/1/186/18673.pdf
1 ./1/1/209/20946.pdf
1 ./1/1/26/2656.pdf
1 ./1/1/33/3384.pdf
1 ./1/1/57/5742.pdf
1 ./1/1/58/5869.pdf
1 ./1/1/63/6395.pdf
1 ./1/1/70/7099.pdf
1 ./1/1/74/7466.pdf


##</code><code>##

1 ./1/1/106/10627.pdf
2 ./1/1/107/10703.pdf
Thread 2 terminated abnormally: *****Global symbol "@ISA" requires explicit pack
age name (did you forget to declare "my @ISA"?) at C:/strawberry-perl-5.28.0.1-3
2bit-PDL/perl/site/lib/Text/PDF/Filter.pm line 342.
Global symbol "@basedict" requires explicit package name (did you forget to decl
are "my @basedict"?) at C:/strawberry-perl-5.28.0.1-32bit-PDL/perl/site/lib/Text
/PDF/Filter.pm line 343.
Global symbol "@basedict" requires explicit package name (did you forget to decl
are "my @basedict"?) at C:/strawberry-perl-5.28.0.1-32bit-PDL/perl/site/lib/Text
/PDF/Filter.pm line 351.
Global symbol "@basedict" requires explicit package name (did you forget to decl
are "my @basedict"?) at C:/strawberry-perl-5.28.0.1-32bit-PDL/perl/site/lib/Text
/PDF/Filter.pm line 374.
Compilation failed in require at C:/strawberry-perl-5.28.0.1-32bit-PDL/perl/site
/lib/CAM/PDF.pm line 5608.
Thread 1 terminated abnormally: *****Global symbol "@ISA" requires explicit pack
age name (did you forget to declare "my @ISA"?) at C:/strawberry-perl-5.28.0.1-3
2bit-PDL/perl/site/lib/Text/PDF/Filter.pm line 342.
Global symbol "@basedict" requires explicit package name (did you forget to decl
are "my @basedict"?) at C:/strawberry-perl-5.28.0.1-32bit-PDL/perl/site/lib/Text
/PDF/Filter.pm line 343.
Global symbol "@basedict" requires explicit package name (did you forget to decl
are "my @basedict"?) at C:/strawberry-perl-5.28.0.1-32bit-PDL/perl/site/lib/Text
/PDF/Filter.pm line 351.
Global symbol "@basedict" requires explicit package name (did you forget to decl
are "my @basedict"?) at C:/strawberry-perl-5.28.0.1-32bit-PDL/perl/site/lib/Text
/PDF/Filter.pm line 374.
Compilation failed in require at C:/strawberry-perl-5.28.0.1-32bit-PDL/perl/site
/lib/CAM/PDF.pm line 5608.


##</code><code>##

die '*****' . $@;