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Diffstat (limited to 'trunk/Echolot/Scheduler.pm')
| -rw-r--r-- | trunk/Echolot/Scheduler.pm | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/trunk/Echolot/Scheduler.pm b/trunk/Echolot/Scheduler.pm new file mode 100644 index 0000000..32d859f --- /dev/null +++ b/trunk/Echolot/Scheduler.pm @@ -0,0 +1,196 @@ +package Echolot::Scheduler; + +# +# $Id$ +# +# This file is part of Echolot - a Pinger for anonymous remailers. +# +# Copyright (c) 2002, 2003, 2004 Peter Palfrader <peter@palfrader.org> +# +# 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; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +# + +=pod + +=head1 Name + +Echolot::Scheduler - Task selector/scheduler for echolot + +=head1 DESCRIPTION + +This package provides several functions for scheduling tasks within +the ping daemon. + +=over + +=cut + +use strict; +use English; +use Echolot::Log; + +my $ORDER = 1; + +=item B<new> () + +Creates a new scheduler object. + +=cut +sub new { + my ($class, %params) = @_; + my $self = {}; + bless $self, $class; + return $self; +}; + +=item B<add> (I<name>, I<interval>, I<offset>, I<missok>, I<what>) + +Adds a task with I<name> to the list of tasks. Every I<interval> seconds +I<what> is called. If for example I<interval> is 3600 - meaning I<what> +should be executed hourly - setting I<offset> to 600 would mean that +it get's called 10 minutes after the hour. + +I<missok> indicates that it is ok to miss one run of this job. This can happen +if we run behind schedule for instance. + +=cut +sub add($$$$$$) { + my ($self, $name, $interval, $offset, $missok, $what) = @_; + + Echolot::Log::logdie("Must not add zero intervall for job $name.") + unless $interval; + + if (defined $self->{'tasks'}->{$name}) { + @{ $self->{'schedule'} } = grep { $_->{'name'} ne $name } @{ $self->{'schedule'} }; + }; + + $self->{'tasks'}->{$name} = + { + interval => $interval, + offset => $offset, + what => $what, + order => $ORDER++, + missok => $missok, + }; + + $self->schedule($name, 1); + + return 1; +}; + +=item B<schedule> (I<name>, I<reschedule>, [ I<for>, [I<arguments>]] ) + +Schedule execution of I<name> for I<for>. If I<for> is not given it is calculated +from I<interval> and I<offset> passed to B<new>. if I<reschedule> is set +the task will be rescheduled when it's done (according to its interval). +You may also give arguments to passed to the task. + +=cut +sub schedule($$$;$$) { + my ($self, $name, $reschedule, $for, $arguments) = @_; + + (defined $self->{'tasks'}->{$name}) or + Echolot::Log::warn("Task $name is not defined."), + return 0; + + my $interval = $self->{'tasks'}->{$name}->{'interval'}; + my $offset = $self->{'tasks'}->{$name}->{'offset'}; + + + unless (defined $for) { + ($interval < 0) and + return 1; + my $now = time(); + $for = $now - $now % $interval + $offset; + ($for <= $now) and $for += $interval; + my $cnt = 0; + while ($self->{'tasks'}->{$name}->{'missok'} && ($for <= $now)) { + $for += $interval; + $cnt ++; + }; + Echolot::Log::debug("Skipping $cnt runs of $name.") if $cnt; + }; + + $arguments = [] unless defined $arguments; + + push @{ $self->{'schedule'} }, + { + start => $for, + order => $self->{'tasks'}->{$name}->{'order'}, + name => $name, + arguments => $arguments, + reschedule => $reschedule + }; + + @{ $self->{'schedule'} } = sort { $a->{'start'} <=> $b->{'start'} or $a->{'order'} <=> $b->{'order'} } + @{ $self->{'schedule'} }; + + return 1; +}; + +=item B<run> () + +Start the scheduling run. + +It will run forever or until a task with I<what> == 'exit' is executed. + +=cut +sub run($) { + my ($self) = @_; + + (defined $self->{'schedule'}->[0]) or + Echolot::Log::warn("Scheduler is empty."), + return 0; + + while(1) { + my $now = time(); + my $task = $self->{'schedule'}->[0]; + if ($task->{'start'} < $now) { + Echolot::Log::warn("Task $task->{'name'} could not be started on time.") + unless ($task->{'start'} == 0); + } else { + Echolot::Log::debug("zZzZZzz."); + $PROGRAM_NAME = "pingd [sleeping]"; + sleep ($task->{'start'} - $now); + }; + + (time() < $task->{'start'}) and + next; + + $now = $task->{'start'}; + do { + $task = shift @{ $self->{'schedule'} }; + my $name = $task->{'name'}; + $PROGRAM_NAME = "pingd [executing $name]"; + (defined $self->{'tasks'}->{$name}) or + Echolot::Log::cluck("Task $task->{'name'} is not defined."); + + my $what = $self->{'tasks'}->{$name}->{'what'}; + Echolot::Log::debug("Running $name (was scheduled for ".(time()-$now)." seconds ago)."); + last if ($what eq 'exit'); + &$what( $now, @{ $task->{'arguments'} } ); + $self->schedule($name, 1, $now + $self->{'tasks'}->{$name}->{'interval'}) if + ($task->{'reschedule'} && $self->{'tasks'}->{$name}->{'interval'} > 0); + + (defined $self->{'schedule'}->[0]) or + Echolot::Log::warn("Scheduler is empty."), + return 0; + } while ($now >= $self->{'schedule'}->[0]->{'start'}); + }; + + return 1; +}; + +# vim: set ts=4 shiftwidth=4: |