Add CleanupTask.

lib/CleanupTask.pm

@@ -0,0 +1,69 @@
+# This program is copyright 2011 Percona Inc.
+# Feedback and improvements are welcome.
+#
+# THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
+# WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+# MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation, version 2; OR the Perl Artistic License.  On UNIX and similar
+# systems, you can issue `man perlgpl' or `man perlartistic' to read these
+# licenses.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+# Place, Suite 330, Boston, MA  02111-1307  USA.
+# ###########################################################################
+# CleanupTask package
+# ###########################################################################
+{
+# Package: CleanupTask
+# CleanupTask does something when the object is destroyed.  This is used,
+# for example, to close all dbh gracefully when a program dies unexpectedly.
+package CleanupTask;
+
+use strict;
+use warnings FATAL => 'all';
+use English qw(-no_match_vars);
+use constant MKDEBUG => $ENV{MKDEBUG} || 0;
+
+# Sub: new
+#
+# Parameters:
+#   task - Callback executed when object is destroyed
+#
+# Returns:
+#   CleanupTask object
+sub new {
+   my ( $class, $task ) = @_;
+   die "I need a task parameter" unless $task;
+   die "The task parameter must be a coderef" unless ref $task eq 'CODE';
+   my $self = {
+      task => $task,
+   };
+   MKDEBUG && _d('Created cleanup task', $task);
+   return bless $self, $class;
+}
+
+sub DESTROY {
+   my ($self) = @_;
+   my $task = $self->{task};
+   MKDEBUG && _d('Calling cleanup task', $task);
+   $task->();
+   return;
+}
+
+sub _d {
+   my ($package, undef, $line) = caller 0;
+   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
+        map { defined $_ ? $_ : 'undef' }
+        @_;
+   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
+}
+
+1;
+}
+# ###########################################################################
+# End CleanupTask package
+# ###########################################################################

t/lib/CleanupTask.t

@@ -0,0 +1,36 @@
+#!/usr/bin/perl
+
+BEGIN {
+   die "The PERCONA_TOOLKIT_BRANCH environment variable is not set.\n"
+      unless $ENV{PERCONA_TOOLKIT_BRANCH} && -d $ENV{PERCONA_TOOLKIT_BRANCH};
+   unshift @INC, "$ENV{PERCONA_TOOLKIT_BRANCH}/lib";
+};
+
+use strict;
+use warnings FATAL => 'all';
+use English qw(-no_match_vars);
+use Test::More tests => 2;
+
+use PerconaTest;
+use CleanupTask;
+
+my $foo = 0;
+{
+   my $set_foo = new CleanupTask(sub { $foo = 42; });
+   is(
+      $foo,
+      0,
+      "Cleanup task not called yet"
+   );
+}
+
+is(
+   $foo,
+   42,
+   "Cleanup task called after obj destroyed"
+);
+
+# #############################################################################
+# Done.
+# #############################################################################
+exit;