use strict;
use warnings;

die "Not UNIX OS\n" if $^O eq 'MSWin32';

# usage: script.pl > out

use Inline 'C' => Config => CCFLAGSEX => '-O2';
use Inline 'C' => <<'END_C';

#include <stdio.h>

void c_fput_float(float value, char c, FILE *stream)
{
  static char buf[] = "0.0\n";

  int whole = (int) value;
  int frac  = (int) ((value - whole) * 10);

  buf[0] = '0' + whole;
  buf[2] = '0' + frac;
  buf[3] = c;

  fputs(buf, stream);
}

unsigned long c_repetition (int fd, float p0)
{
  unsigned long count = 0;
  FILE *stream = fdopen(fd, "wb");
  float p1,p2,p3,p4,p5,p6,p7,p8,p9,p10;

  for (p1=0; p1<=1; p1+=0.2) {
    for (p2=0; p2<=1; p2+=0.2) {
      for (p3=0; p3<=1; p3+=0.2) {
        for (p4=0; p4<=1; p4+=0.2) {
          for (p5=0; p5<=1; p5+=0.2) {
            for (p6=0; p6<=1; p6+=0.2) {
              for (p7=0; p7<=1; p7+=0.2) {
                for (p8=0; p8<=1; p8+=0.2) {
                  for (p9=0; p9<=1; p9+=0.2) {
                    for (p10=0; p10<=1; p10+=0.2) {
                      c_fput_float(p0,  '\t', stream);
                      c_fput_float(p1,  '\t', stream);
                      c_fput_float(p2,  '\t', stream);
                      c_fput_float(p3,  '\t', stream);
                      c_fput_float(p4,  '\t', stream);
                      c_fput_float(p5,  '\t', stream);
                      c_fput_float(p6,  '\t', stream);
                      c_fput_float(p7,  '\t', stream);
                      c_fput_float(p8,  '\t', stream);
                      c_fput_float(p9,  '\t', stream);
                      c_fput_float(p10, '\t', stream);
                      c_fput_float(1.0, '\t', stream);
                      c_fput_float(1.0, '\n', stream);
                      count++;
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }

  fflush(stream);
  fclose(stream);

  return count;
}

END_C

# Run on UNIX machines with 48+ GiB of RAM.
# Otherwise, remove the -use_dev_shm argument.
# Beware, consumes 18 GiB in temp dir.

use MCE::Signal qw[ $tmp_dir -use_dev_shm ];
use Time::HiRes qw[ time ];

use MCE::Loop;
use MCE::Shared;

my $start = time;
my $c_shared = MCE::Shared->scalar(0);

MCE::Loop::init {
  max_workers => 6,
  chunk_size  => 1
};

# loop through desired combinations	
mce_loop_s {
  my $p0 = $_;
  open my $fh, ">", "$tmp_dir/".MCE->chunk_id();
  my $c = c_repetition(fileno($fh), $p0);
  close $fh;

  $c_shared->incrby($c);

} 0.0, 1.0, 0.2, '%0.1f'; # p0: seq_beg, seq_end, seq_step, format

MCE::Loop::finish();

system("cat $tmp_dir/[1-6]; rm -fr $tmp_dir");

printf STDERR "Took: %0.3f seconds [%ld]\n", time() - $start, $c_shared->get();