This is my safe set exerciser, which does crashes giving out the following error.

Thread <X> terminated abnormally: panic: MUTEX_LOCK (22) shared.xs:199 at ./thread_test.pl line 25.

I checked this multiple times but did not find anything wrong with it. May be a problem with the safe_set as I indicated in my post or may be not? 

#! perl -slw

use strict;
use threads;
use threads::shared;

our %h : shared;

# Setting up just a single row to increase chances 
# a race condition
our $k = 'AAA';
our $val : shared = 0;
our $THREADS = 50;
our $iter = 50;
$h{$k} = \$val;

# Safe_set similar to BrowserUk 
sub safe_set {
  my $v :shared;
  # Critical Section
  {
     lock ${$h{$k}};
     $v = ${$h{$k}} + 1;
     $h{$k} = \$v;
  }
}

# Keep locking to increment $$h{$k}
sub test_safe_set {
  for (my $i = 0; $i < $iter; ++$i) {
     safe_set();
  }
}

my @pool = map{
      threads->create(\&test_safe_set)
    } 1 .. $THREADS;

$_->join for @pool;

warn ${$h{$k}}, "failed\n" if ${$h{$k}} != $THREADS * $iter;

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In reply to Re^4: Avoid Locking Entire Hashes by jagan_1234
in thread Avoid Locking Entire Hashes by jagan_1234

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