Re: hashes & threads

[marioroy]

gravid, welcome to the monastery.

The following provide 4 demonstrations. MCE modules support Perl not built with threads support. The forth demonstration ensures graceful IO from shared storage or from a network-based file system. In that case, MCE does sequential IO among workers. Parallel IO is possible by adding the MCE option: parallel_io => 1, to have workers read simultaneously (random IO).

threads and threads::shared

use strict;
use warnings;

use threads;
use threads::shared;

my @dirs = qw( a b c d e f );
my %hash = map { $_ => shared_clone({}) } @dirs;

my @thrs;

foreach my $dir (@dirs) {
  if (-e "$dir/syn.log") {
    push @thrs, threads->create(\&process_1_file, $dir, "syn.log");
  }
}

$_->join for @thrs;

print $hash{"a"}{"area"}, "\n";

sub process_1_file  {
  my ($dir, $file) = @_;
  open(my $fh, "$dir/$file") or die "cannot open $dir/$file $!";
  while (<$fh>) {
    chomp;
    if ($_ =~ /^area=(.*)/) {
      $hash{"$dir"}{"area"} = $1;
    }
  }
}

MCE::Hobo and MCE::Shared

use strict;
use warnings;

use MCE::Hobo;
use MCE::Shared;

my @dirs = qw( a b c d e f );
my %hash = map { $_ => MCE::Shared->hash } @dirs;

foreach my $dir (@dirs) {
  if (-e "$dir/syn.log") {
    MCE::Hobo->create(\&process_1_file, $dir, "syn.log");
  }
}

MCE::Hobo->waitall;

print $hash{"a"}{"area"}, "\n";

sub process_1_file  {
  my ($dir, $file) = @_;
  open(my $fh, "$dir/$file") or die "cannot open $dir/$file $!";
  while (<$fh>) {
    chomp;
    if ($_ =~ /^area=(.*)/) {
      $hash{"$dir"}{"area"} = $1;
    }
  }
}

MCE::Loop and MCE::Shared

use strict;
use warnings;

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

my @dirs = qw( a b c d e f );
my %hash = map { $_ => MCE::Shared->hash } @dirs;

MCE::Loop->init(
   max_workers => $#dirs,
   chunk_size  => 1
);

mce_loop {
  my $dir = $_;
  proccess_1_file($dir, "syn.log") if (-e "$dir/syn.log");
} @dirs;

print $hash{"a"}{"area"}, "\n";

sub proccess_1_file  {
  my ($dir, $file) = @_;
  open(my $fh, "$dir/$file") or die "cannot open $dir/$file $!";
  while (<$fh>) {
    chomp;
    if ($_ =~ /^area=(.*)/) {
      $hash{"$dir"}{"area"} = $1;
    }
  }
}

MCE and MCE::Shared

use strict;
use warnings;

use MCE;
use MCE::Shared;

my @dirs = qw( a b c d e f );
my %hash = map { $_ => MCE::Shared->hash } @dirs;

my $mce = MCE->new(
  max_workers => 4,
  chunk_size  => '12m',
  use_slurpio => 1,

  user_func   => sub {
    my ($mce, $slurp_ref, $chunk_id) = @_;
    my $dir = $mce->user_args()->[0];
    open my $MEM_FH, "<", $slurp_ref;
    while (<$MEM_FH>) {
      chomp;
      if ($_ =~ /^area=(.*)/) {
        $hash{"$dir"}{"area"} = $1;
      }
    }
    close $MEM_FH;
  }

)->spawn;

foreach my $dir (@dirs) {
  if (-e "$dir/syn.log") {
    $mce->process({ user_args => [ $dir ] }, "$dir/syn.log");
  }
}

$mce->shutdown;

print $hash{"a"}{"area"}, "\n";

Warm regards. Mario