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# Data and accessors to manage POE's events.
package POE::Resource::Events;
use vars qw($VERSION);
$VERSION = '1.288'; # NOTE - Should be #.### (three decimal places)
# These methods are folded into POE::Kernel;
package POE::Kernel;
use strict;
# A local copy of the queue so we can manipulate it directly.
my $kr_queue;
my %event_count;
# ( $session => $count,
# ...,
# );
my %post_count;
# ( $session => $count,
# ...,
# );
### Begin-run initialization.
sub _data_ev_initialize {
my ($self, $queue) = @_;
$kr_queue = $queue;
}
### End-run leak checking.
sub _data_ev_finalize {
my $finalized_ok = 1;
while (my ($ses, $cnt) = each(%event_count)) {
$finalized_ok = 0;
_warn("!!! Leaked event-to count: $ses = $cnt\n");
}
while (my ($ses, $cnt) = each(%post_count)) {
$finalized_ok = 0;
_warn("!!! Leaked event-from count: $ses = $cnt\n");
}
return $finalized_ok;
}
### Enqueue an event.
sub _data_ev_enqueue {
my (
$self,
$session, $source_session, $event, $type, $etc,
$file, $line, $fromstate, $time
) = @_;
if (ASSERT_DATA) {
unless ($self->_data_ses_exists($session)) {
_trap(
"<ev> can't enqueue event ``$event'' for nonexistent session $session\n"
);
}
}
# This is awkward, but faster than using the fields individually.
my $event_to_enqueue = [ @_[1..8] ];
my $old_head_priority = $kr_queue->get_next_priority();
my $new_id = $kr_queue->enqueue($time, $event_to_enqueue);
if (TRACE_EVENTS) {
_warn(
"<ev> enqueued event $new_id ``$event'' from ",
$self->_data_alias_loggable($source_session), " to ",
$self->_data_alias_loggable($session),
" at $time"
);
}
if ($kr_queue->get_item_count() == 1) {
$self->loop_resume_time_watcher($time);
}
elsif ($time < $old_head_priority) {
$self->loop_reset_time_watcher($time);
}
# This is the counterpart to _data_ev_refcount_dec(). It's only
# used in one place, so it's not in its own function.
$event_count{$session}++;
$self->_data_ses_refcount_inc($session);
$post_count{$source_session}++;
$self->_data_ses_refcount_inc($source_session);
return $new_id;
}
### Remove events sent to or from a specific session.
sub _data_ev_clear_session {
my ($self, $session) = @_;
my $my_event = sub {
($_[0]->[EV_SESSION] == $session) || ($_[0]->[EV_SOURCE] == $session)
};
# TODO - This is probably incorrect. The total event count will be
# artificially inflated for events from/to the same session. That
# is, a yield() will count twice.
my $total_event_count = (
($event_count{$session} || 0) +
($post_count{$session} || 0)
);
foreach ($kr_queue->remove_items($my_event, $total_event_count)) {
$self->_data_ev_refcount_dec(@{$_->[ITEM_PAYLOAD]}[EV_SOURCE, EV_SESSION]);
}
croak if delete $event_count{$session};
croak if delete $post_count{$session};
}
# TODO Alarm maintenance functions may move out to a separate
# POE::Resource module in the future. Why? Because alarms may
# eventually be managed by something other than the event queue.
# Especially if we incorporate a proper Session scheduler. Be sure to
# move the tests to a corresponding t/res/*.t file.
### Remove a specific alarm by its name. This is in the events
### section because alarms are currently implemented as events with
### future due times.
sub _data_ev_clear_alarm_by_name {
my ($self, $session, $alarm_name) = @_;
my $my_alarm = sub {
return 0 unless $_[0]->[EV_TYPE] & ET_ALARM;
return 0 unless $_[0]->[EV_SESSION] == $session;
return 0 unless $_[0]->[EV_NAME] eq $alarm_name;
return 1;
};
foreach ($kr_queue->remove_items($my_alarm)) {
$self->_data_ev_refcount_dec(@{$_->[ITEM_PAYLOAD]}[EV_SOURCE, EV_SESSION]);
}
}
### Remove a specific alarm by its ID. This is in the events section
### because alarms are currently implemented as events with future due
### times. TODO It's possible to remove non-alarms; is that wrong?
sub _data_ev_clear_alarm_by_id {
my ($self, $session, $alarm_id) = @_;
my $my_alarm = sub {
$_[0]->[EV_SESSION] == $session;
};
my ($time, $id, $event) = $kr_queue->remove_item($alarm_id, $my_alarm);
return unless defined $time;
if (TRACE_EVENTS) {
_warn(
"<ev> removed event $id ``", $event->[EV_NAME], "'' to ",
$self->_data_alias_loggable($session), " at $time"
);
}
$self->_data_ev_refcount_dec( @$event[EV_SOURCE, EV_SESSION] );
return ($time, $event);
}
### Remove all the alarms for a session. Whoot!
sub _data_ev_clear_alarm_by_session {
my ($self, $session) = @_;
my $my_alarm = sub {
return 0 unless $_[0]->[EV_TYPE] & ET_ALARM;
return 0 unless $_[0]->[EV_SESSION] == $session;
return 1;
};
my @removed;
foreach ($kr_queue->remove_items($my_alarm)) {
my ($time, $event) = @$_[ITEM_PRIORITY, ITEM_PAYLOAD];
$self->_data_ev_refcount_dec( @$event[EV_SOURCE, EV_SESSION] );
push @removed, [ $event->[EV_NAME], $time, @{$event->[EV_ARGS]} ];
}
return @removed;
}
### Decrement a post refcount
sub _data_ev_refcount_dec {
my ($self, $source_session, $dest_session) = @_;
if (ASSERT_DATA) {
_trap $dest_session unless exists $event_count{$dest_session};
_trap $source_session unless exists $post_count{$source_session};
}
$event_count{$dest_session}--;
$self->_data_ses_refcount_dec($dest_session);
$post_count{$source_session}--;
$self->_data_ses_refcount_dec($source_session);
}
### Fetch the number of pending events sent to a session.
sub _data_ev_get_count_to {
my ($self, $session) = @_;
return $event_count{$session} || 0;
}
### Fetch the number of pending events sent from a session.
sub _data_ev_get_count_from {
my ($self, $session) = @_;
return $post_count{$session} || 0;
}
### Dispatch events that are due for "now" or earlier.
sub _data_ev_dispatch_due {
my $self = shift;
if (TRACE_EVENTS) {
foreach ($kr_queue->peek_items(sub { 1 })) {
my @event = map { defined() ? $_ : "(undef)" } @{$_->[ITEM_PAYLOAD]};
_warn(
"<ev> time($_->[ITEM_PRIORITY]) id($_->[ITEM_ID]) ",
"event(@event)\n"
);
}
}
my $now = time();
my $next_time;
while (defined($next_time = $kr_queue->get_next_priority())) {
last if $next_time > $now;
my ($due_time, $id, $event) = $kr_queue->dequeue_next();
if (TRACE_EVENTS) {
_warn("<ev> dispatching event $id ($event->[EV_NAME])");
}
# An event is "blocked" if its due time is earlier than the
# current time. This means that the event has had to wait before
# being dispatched. As far as I can tell, all events will be
# "blocked" according to these rules.
if ($due_time < $now) {
$self->_data_stat_add('blocked', 1);
$self->_data_stat_add('blocked_seconds', $now - $due_time);
}
# TODO - Can these two lines be reversed?
# TODO - May avoid entering/removing GC mark entries.
$self->_data_ev_refcount_dec($event->[EV_SOURCE], $event->[EV_SESSION]);
$self->_dispatch_event(@$event, $due_time, $id);
# Stop the system if an unhandled exception occurred.
# This wipes out all sessions and associated resources.
POE::Kernel->stop() if $POE::Kernel::kr_exception;
}
# Sweep for dead sessions. The sweep may alter the next queue time.
$self->_data_ses_gc_sweep();
$next_time = $kr_queue->get_next_priority();
# Tell the event loop to wait for the next event, if there is one.
# Otherwise we're going to wait indefinitely for some other event.
if (defined $next_time) {
$self->loop_reset_time_watcher($next_time);
}
else {
$self->loop_pause_time_watcher();
}
}
1;
__END__
=head1 NAME
POE::Resource::Events - internal event manager for POE::Kernel
=head1 SYNOPSIS
There is no public API.
=head1 DESCRIPTION
POE::Resource::Events is a mix-in class for POE::Kernel. It hides the
complexity of managing POE's events from even POE itself. It is used
internally by POE::Kernel, so it has no public interface.
=head1 SEE ALSO
See L<POE::Kernel/Asynchronous Messages (FIFO Events)> for one public
events API.
See L<POE::Kernel/Resources> for for public information about POE
resources.
See L<POE::Resource> for general discussion about resources and the
classes that manage them.
=head1 BUGS
None known.
=head1 AUTHORS & COPYRIGHTS
Please see L<POE> for more information about authors and contributors.
=cut
# rocco // vim: ts=2 sw=2 expandtab
# TODO - Edit.
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