Files
percona-toolkit/lib/CleanupTask.pm
2013-01-02 17:19:16 -07:00

85 lines
2.8 KiB
Perl

# This program is copyright 2011 Percona Ireland Ltd.
# 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 PTDEBUG => $ENV{PTDEBUG} || 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,
};
open $self->{stdout_copy}, ">&=", *STDOUT
or die "Cannot dup stdout: $OS_ERROR";
open $self->{stderr_copy}, ">&=", *STDERR
or die "Cannot dup stderr: $OS_ERROR";
PTDEBUG && _d('Created cleanup task', $task);
return bless $self, $class;
}
sub DESTROY {
my ($self) = @_;
my $task = $self->{task};
if ( ref $task ) {
PTDEBUG && _d('Calling cleanup task', $task);
# Temporarily restore STDOUT and STDERR to what they were
# when the object was created
open local(*STDOUT), ">&=", $self->{stdout_copy}
if $self->{stdout_copy};
open local(*STDERR), ">&=", $self->{stderr_copy}
if $self->{stderr_copy};
$task->();
}
else {
warn "Lost cleanup task";
}
return;
}
sub _d {
my ($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
# ###########################################################################