package Echolot::Scheduler; # (c) 2002 Peter Palfrader # $Id: Scheduler.pm,v 1.16 2003/06/06 11:50:30 weasel Exp $ # =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 $ORDER = 1; =item B () Creates a new scheduler object. =cut sub new { my ($class, %params) = @_; my $self = {}; bless $self, $class; return $self; }; =item B (I, I, I, I, I) Adds a task with I to the list of tasks. Every I seconds I is called. If for example I is 3600 - meaning I should be executed hourly - setting I to 600 would mean that it get's called 10 minutes after the hour. I 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($$$$$$) { my ($self, $name, $interval, $offset, $missok, $what) = @_; Echolot::Log::logdie("Must not add zero intervall for job $name.") unless $interval; if (defined $self->{'tasks'}->{$name}) { @{ $self->{'schedule'} } = grep { $_->{'name'} ne $name } @{ $self->{'schedule'} }; }; $self->{'tasks'}->{$name} = { interval => $interval, offset => $offset, what => $what, order => $ORDER++, missok => $missok, }; $self->schedule($name, 1); return 1; }; =item B (I, I, [ I, [I]] ) Schedule execution of I for I. If I is not given it is calculated from I and I passed to B. if I is set the task will be rescheduled when it's done (according to its interval). You may also give arguments to passed to the task. =cut sub schedule($$$;$$) { 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'} } @{ $self->{'schedule'} }; return 1; }; =item B () Start the scheduling run. It will run forever or until a task with I == 'exit' is executed. =cut sub run($) { 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: