Refactor PBot::Timer into PBot::EventQueue

Make better use of PBot::IRC's select loop
Remove use of SIGALRM

PBot/AntiFlood.pm

@@ -36,7 +36,7 @@ sub initialize {
     $self->{'ban-exemptions'} = PBot::DualIndexHashObject->new(name => 'Ban exemptions', filename => $filename, pbot => $self->{pbot});
     $self->{'ban-exemptions'}->load;
 
-    $self->{pbot}->{timer}->register(sub { $self->adjust_offenses }, 60 * 60 * 1, 'AntiFlood Adjust Offenses');
+    $self->{pbot}->{event_queue}->enqueue(sub { $self->adjust_offenses }, 60 * 60 * 1, 'Adjust anti-flood offenses');
 
     $self->{pbot}->{registry}->add_default('text', 'antiflood', 'enforce', $conf{enforce_antiflood} // 1);
 

PBot/BanList.pm

@@ -59,7 +59,7 @@ sub initialize {
     $self->{ban_queue}   = {};
     $self->{unban_queue} = {};
 
-    $self->{pbot}->{timer}->register(sub { $self->flush_unban_queue }, 30, 'Unban Queue');
+    $self->{pbot}->{event_queue}->enqueue(sub { $self->flush_unban_queue }, 30, 'Flush unban queue');
 }
 
 sub cmd_banlist {
@@ -203,7 +203,7 @@ sub compare_banlist {
             $self->{pbot}->{logger}->log("BanList: Saved ban +b $mask no longer exists in $channel.\n");
             # TODO option to restore ban
             $self->{banlist}->remove($channel, $mask, undef, 1);
-            $self->{pbot}->{timer}->dequeue_event("unban $channel $mask");
+            $self->{pbot}->{event_queue}->dequeue_event("unban $channel $mask");
         }
     }
 
@@ -248,7 +248,7 @@ sub compare_quietlist {
             $self->{pbot}->{logger}->log("BanList: Saved quiet +q $mask no longer exists in $channel.\n");
             # TODO option to restore quiet
             $self->{quietlist}->remove($channel, $mask, undef, 1);
-            $self->{pbot}->{timer}->dequeue_event("unmute $channel $mask");
+            $self->{pbot}->{event_queue}->dequeue_event("unmute $channel $mask");
         }
     }
 
@@ -294,15 +294,15 @@ sub track_mode {
 
         if ($mode eq "-b") {
             $self->{banlist}->remove($channel, $mask);
-            $self->{pbot}->{timer}->dequeue_event("unban $channel $mask");
+            $self->{pbot}->{event_queue}->dequeue_event("unban $channel $mask");
 
             # freenode strips channel forwards from unban result if no ban exists with a channel forward
             my $join_flood_channel = $self->{pbot}->{registry}->get_value('antiflood', 'join_flood_channel') // '#stop-join-flood';
             $self->{banlist}->remove($channel, "$mask\$$join_flood_channel");
-            $self->{pbot}->{timer}->dequeue_event(lc "unban $channel $mask\$$join_flood_channel");
+            $self->{pbot}->{event_queue}->dequeue_event(lc "unban $channel $mask\$$join_flood_channel");
         } elsif ($mode eq "-$mute_char") {
             $self->{quietlist}->remove($channel, $mask);
-            $self->{pbot}->{timer}->dequeue_event("unmute $channel $mask");
+            $self->{pbot}->{event_queue}->dequeue_event("unmute $channel $mask");
         }
     }
 
@@ -312,7 +312,7 @@ sub track_mode {
         if ($nick eq "ChanServ" or $mask =~ m/##fix_your_connection$/i) {
             if ($self->{banlist}->exists($channel, $mask)) {
                 $self->{banlist}->set($channel, $mask, 'timeout', gettimeofday + $self->{pbot}->{registry}->get_value('banlist', 'chanserv_ban_timeout'));
-                $self->{pbot}->{timer}->update_interval("unban $channel $mask", $self->{pbot}->{registry}->get_value('banlist', 'chanserv_ban_timeout'));
+                $self->{pbot}->{event_queue}->update_interval("unban $channel $mask", $self->{pbot}->{registry}->get_value('banlist', 'chanserv_ban_timeout'));
             } else {
                 my $data = {
                     reason    => 'Temp ban for banned-by-ChanServ or mask is *!*@*##fix_your_connection',
@@ -349,7 +349,7 @@ sub track_mode {
             $self->{pbot}->{logger}->log("WEIRD MUTE THING $nick...\n");
             if ($self->{quietlist}->exists($channel, $mask)) {
                 $self->{quietlist}->set($channel, $mask, 'timeout', gettimeofday + $self->{pbot}->{registry}->get_value('banlist', 'chanserv_ban_timeout'));
-                $self->{pbot}->{timer}->update_interval("unmute $channel $mask", $self->{pbot}->{registry}->get_value('banlist', 'chanserv_ban_timeout'));
+                $self->{pbot}->{event_queue}->update_interval("unmute $channel $mask", $self->{pbot}->{registry}->get_value('banlist', 'chanserv_ban_timeout'));
             } else {
                 my $data = {
                     reason    => 'Temp mute',
@@ -557,7 +557,7 @@ sub ban_user_timed {
     }
 
     my $method = $mode eq 'b' ? 'unban' : 'unmute';
-    $self->{pbot}->{timer}->dequeue_event("$method $channel $mask");
+    $self->{pbot}->{event_queue}->dequeue_event("$method $channel $mask");
 
     if ($length > 0) {
         $self->enqueue_unban($channel, $mode, $mask, $length);
@@ -704,9 +704,9 @@ sub enqueue_unban {
 
     my $method = $mode eq 'b' ? 'unban' : 'unmute';
 
-    $self->{pbot}->{timer}->enqueue_event(
+    $self->{pbot}->{event_queue}->enqueue_event(
         sub {
-            $self->{pbot}->{timer}->update_interval("$method $channel $hostmask", 60 * 15, 1); # try again in 15 minutes
+            $self->{pbot}->{event_queue}->update_interval("$method $channel $hostmask", 60 * 15, 1); # try again in 15 minutes
             return if not $self->{pbot}->{joined_channels};
             $self->unban_user($channel, $mode, $hostmask);
         }, $interval, "$method $channel $hostmask", 1

PBot/ChanOps.pm

@@ -27,7 +27,8 @@ sub initialize {
 
     $self->{pbot}->{registry}->add_default('text', 'general', 'deop_timeout', 300);
 
-    $self->{pbot}->{timer}->register(sub { $self->check_opped_timeouts },  10, 'Check Opped Timeouts');
+    # TODO: enqueue OP events as needed instead of naively checking every 10 seconds
+    $self->{pbot}->{event_queue}->enqueue(sub { $self->check_opped_timeouts },  10, 'Check opped timeouts');
 }
 
 sub track_mode {

PBot/Channels.pm

@@ -82,8 +82,8 @@ sub cmd_remove {
     # clear banlists
     $self->{pbot}->{banlist}->{banlist}->remove($context->{arguments});
     $self->{pbot}->{banlist}->{quietlist}->remove($context->{arguments});
-    $self->{pbot}->{timer}->dequeue_event("unban $context->{arguments} .*");
+    $self->{pbot}->{event_queue}->dequeue_event("unban $context->{arguments} .*");
-    $self->{pbot}->{timer}->dequeue_event("unmute $context->{arguments} .*");
+    $self->{pbot}->{event_queue}->dequeue_event("unmute $context->{arguments} .*");
 
     # TODO: ignores, etc?
     return $self->{channels}->remove($context->{arguments});

PBot/DualIndexHashObject.pm

@@ -125,7 +125,7 @@ sub save {
 
     if ($self->{save_queue_timeout}) {
         # enqueue the save to prevent save-thrashing
-        $self->{pbot}->{timer}->replace_subref_or_enqueue_event(
+        $self->{pbot}->{enqueue_event}->replace_subref_or_enqueue_event(
             $subref,
             $self->{save_queue_timeout},
             "save $self->{name}",

PBot/DualIndexSQLiteObject.pm

@@ -39,7 +39,7 @@ sub initialize {
     $self->{pbot}->{registry}->add_trigger('dualindexsqliteobject', "debug_$self->{name}", sub { $self->sqlite_debug_trigger(@_) });
 
     $self->{pbot}->{atexit}->register(sub { $self->end; return; });
-    $self->{pbot}->{timer}->register(sub {$self->trim_cache }, 60, "DualIndexSQLiteObject $self->{name} Timer");
+    $self->{pbot}->{event_queue}->enqueue(sub {$self->trim_cache }, 60, "Trim $self->{name} cache");
 
     $self->begin;
 }
@@ -80,7 +80,7 @@ sub end {
         $self->{dbh} = undef;
     }
 
-    $self->{pbot}->{timer}->unregister("DualIndexSQLiteObject $self->{name} Timer");
+    $self->{pbot}->{event_queue}->dequeue("Trim $self->{name} cache");
 }
 
 sub load  {

PBot/EventDispatcher.pm

@@ -1,6 +1,8 @@
 # File: EventDispatcher.pm
 #
 # Purpose: Registers event handlers and dispatches events to them.
+#
+# Note: PBot::EventDispatcher has no relation to PBot::EventQueue.
 
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this

PBot/EventQueue.pm

@@ -1,50 +1,33 @@
-# File: Timer.pm
+# File: EventQueue.pm
 #
-# Purpose: Provides functionality to register subroutines/events to be invoked
+# Purpose: Provides functionality to manage event subroutines which are invoked
 # at a future time, optionally recurring.
 #
-# If no subroutines/events are registered/enqueued, the default on_tick()
+# Note: PBot::EventQueue has no relation to PBot::EventDispatcher.
-# method, which can be overridden, is invoked.
-#
-# Uses own internal seconds counter and relative-intervals to avoid
-# timeout desyncs due to system clock changes.
-#
-# Note: Uses ALARM signal.
 
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-package PBot::Timer;
+package PBot::EventQueue;
 use parent 'PBot::Class';
 
 use PBot::Imports;
 
-use Time::Duration qw/concise duration/;
+use Time::HiRes qw/time/;
-
+use Time::Duration;
-our $seconds //= 0;
-our $waitfor //= 1;
-our @timer_funcs;
-
-# alarm signal handler (poor-man's timer)
-$SIG{ALRM} = sub {
-    $seconds += $waitfor;
-    foreach my $func (@timer_funcs) { &$func; }
-};
 
 sub initialize {
     my ($self, %conf) = @_;
-    my $timeout          = $conf{timeout} // 10;
+
-    $self->{name}        = $conf{name} // "Unnamed ${timeout}s Timer";
+    # array of pending events
-    $self->{enabled}     = 0;
     $self->{event_queue} = [];
-    $self->{last}        = $seconds;
-    $self->{timeout}     = $timeout;
 
-    $self->{pbot}->{commands}->register(sub { $self->cmd_eventqueue(@_) },  'eventqueue', 1);
+    # register `eventqueue` bot command
+    $self->{pbot}->{commands}->register(sub { $self->cmd_eventqueue(@_) }, 'eventqueue', 1);
+
+    # add `can-eventqueue` capability to admin group
     $self->{pbot}->{capabilities}->add('admin', 'can-eventqueue', 1);
-
-    $self->{timer_func} = sub { $self->on_tick_handler(@_) };
 }
 
 sub cmd_eventqueue {
@@ -63,6 +46,7 @@ sub cmd_eventqueue {
 
         my $result = eval {
             my $text = "Queued events:\n";
+
             my ($regex) = $self->{pbot}->{interpreter}->shift_arg($context->{arglist});
 
             my $i = 0;
@@ -76,19 +60,29 @@ sub cmd_eventqueue {
 
                 $events++;
 
-                my $duration = concise duration $event->{timeout} - $seconds;
+                my $duration = $event->{timeout} - time;
-                $text .= "  $i) in $duration: $event->{id}";
+
+                if ($duration < 0) {
+                    # current time has passed an event's time but the
+                    # event hasn't left the queue yet. we'll show these
+                    # as, e.g., "pending 5s ago"
+                    $duration = 'pending ' . concise ago -$duration;
+                } else {
+                    $duration = 'in ' . concise duration $duration;
+                }
+
+                $text .= "  $i) $duration: $event->{id}";
                 $text .= ' [R]' if $event->{repeating};
                 $text .= ";\n";
             }
 
             return "No events found." if $events == 0;
 
-            return $text;
+            return $text . "$events events.\n";
         };
 
-        if ($@) {
+        if (my $error = $@) {
-            my $error = $@;
+            # strip source information to prettify error for non-developer consumption
             $error =~ s/ at PBot.*//;
             return "Bad regex: $error";
         }
@@ -98,22 +92,28 @@ sub cmd_eventqueue {
 
     if ($command eq 'add') {
         my ($duration, $command) = $self->{pbot}->{interpreter}->split_args($context->{arglist}, 2);
-        return "Usage: eventqueue add <relative time> <command> [-repeat]" if not defined $duration or not defined $command;
 
-        my ($delay, $error) = $self->{pbot}->{parsedate}->parsedate($duration);
+        if (not defined $duration or not defined $command) {
+            return "Usage: eventqueue add <relative time> <command> [-repeat]";
+        }
+
+        # convert text like "5 minutes" or "1 week" or "next tuesday" to seconds
+        my ($seconds, $error) = $self->{pbot}->{parsedate}->parsedate($duration);
         return $error if defined $error;
 
-        my $repeating = 0;
+        # check for `-repeating` at front or end of command
-        $repeating = 1 if $command =~ s/^-repeat\s+|\s+-repeat$//g;
+        my $repeating = $command =~ s/^-repeat\s+|\s+-repeat$//g;
 
         my $cmd = {
-            nick => $context->{nick},
+            nick     => $context->{nick},
-            user => $context->{user},
+            user     => $context->{user},
-            host => $context->{host},
+            host     => $context->{host},
-            command => $command,
+            hostmask => $context->{hostmask},
+            command  => $command,
         };
 
-        $self->{pbot}->{interpreter}->add_to_command_queue($context->{from}, $cmd, $delay, $repeating);
+        $self->{pbot}->{interpreter}->add_to_command_queue($context->{from}, $cmd, $seconds, $repeating);
+
         return "Command added to event queue.";
     }
 
@@ -127,44 +127,39 @@ sub cmd_eventqueue {
     return "Unknown command '$command'. $usage";
 }
 
-sub start {
-    my $self = shift;
-    $self->{enabled} = 1;
-    push @timer_funcs, $self->{timer_func};
-    alarm 1;
-}
-
-sub stop {
-    my $self = shift;
-    $self->{enabled} = 0;
-    @timer_funcs = grep { $_ != $self->{timer_func} } @timer_funcs;
-}
-
 sub find_enqueue_position {
-    my ($self, $value) = @_;
+    my ($self, $time) = @_;
 
+    # no events in queue yet, early-return first position
     return 0 if not @{$self->{event_queue}};
 
-    if ($value < $self->{event_queue}->[0]->{timeout}) {
+    # early-return first position if event's time is less
+    # than first position's
+    if ($time < $self->{event_queue}->[0]->{timeout}) {
         return 0;
     }
 
-    if ($value > $self->{event_queue}->[@{$self->{event_queue}} - 1]->{timeout}) {
+    # early-return last position if event's time is greater
+    if ($time > $self->{event_queue}->[@{$self->{event_queue}} - 1]->{timeout}) {
         return scalar @{$self->{event_queue}};
     }
 
+    # binary search to find enqueue position
+
     my $lo = 0;
     my $hi = scalar @{$self->{event_queue}} - 1;
 
     while ($lo <= $hi) {
         my $mid = int (($hi + $lo) / 2);
 
-        if ($value < $self->{event_queue}->[$mid]->{timeout}) {
+        if ($time < $self->{event_queue}->[$mid]->{timeout}) {
             $hi = $mid - 1;
-        } elsif ($value > $self->{event_queue}->[$mid]->{timeout}) {
+        } elsif ($time > $self->{event_queue}->[$mid]->{timeout}) {
             $lo = $mid + 1;
         } else {
-            while ($mid < @{$self->{event_queue}} and $self->{event_queue}->[$mid]->{timeout} == $value) {
+            while ($mid < @{$self->{event_queue}} and $self->{event_queue}->[$mid]->{timeout} == $time) {
+                # found a slot with the same time. we "slide" down the array
+                # to append this event to the end of this region of same-times.
                 $mid++;
             }
             return $mid;
@@ -175,57 +170,64 @@ sub find_enqueue_position {
 }
 
 sub replace_subref_or_enqueue_event {
-    my ($self, $ref, $interval, $id, $repeating) = @_;
+    my ($self, $subref, $interval, $id, $repeating) = @_;
 
+    # find events matching id
     my @events = grep { $_->{id} eq $id } @{$self->{event_queue}};
 
+    # no events found, enqueue new event
     if (not @events) {
-        $self->enqueue_event($ref, $interval, $id, $repeating);
+        $self->enqueue_event($subref, $interval, $id, $repeating);
         return;
     }
 
+    # otherwise update existing events
     foreach my $event (@events) {
-        $event->{subref} = $ref;
+        $event->{subref} = $subref;
     }
 }
 
 sub replace_or_enqueue_event {
-    my ($self, $ref, $interval, $id, $repeating) = @_;
+    my ($self, $subref, $interval, $id, $repeating) = @_;
+
+    # remove event if it exists
     $self->dequeue_event($id) if $self->exists($id);
-    $self->enqueue_event($ref, $interval, $id, $repeating);
+
+    # enqueue new event
+    $self->enqueue_event($subref, $interval, $id, $repeating);
 }
 
 sub enqueue_event_unless_exists {
-    my ($self, $ref, $interval, $id, $repeating) = @_;
+    my ($self, $subref, $interval, $id, $repeating) = @_;
+
+    # event already exists, bail out
     return if $self->exists($id);
-    $self->enqueue_event($ref, $interval, $id, $repeating);
+
+    # enqueue new event
+    $self->enqueue_event($subref, $interval, $id, $repeating);
 }
 
 sub enqueue_event {
-    my ($self, $ref, $interval, $id, $repeating) = @_;
+    my ($self, $subref, $interval, $id, $repeating) = @_;
 
-    $id        //= 'anonymous event';
+    $id        //= 'an event';
     $repeating //= 0;
     $interval  //= 0;
 
     my $event = {
         id        => $id,
-        subref    => $ref,
+        subref    => $subref,
         interval  => $interval,
-        timeout   => $seconds + $interval,
+        timeout   => time + $interval,
         repeating => $repeating,
     };
 
     my $i = $self->find_enqueue_position($event->{timeout});
     splice @{$self->{event_queue}}, $i, 0, $event;
 
-    if ($interval < $waitfor) {
+    my $debug = $self->{pbot}->{registry}->get_value('eventqueue', 'debug') // 0;
-        $self->waitfor($interval);
-    }
-
-    my $debug = $self->{pbot}->{registry}->get_value('timer', 'debug') // 0;
     if ($debug > 1) {
-        $self->{pbot}->{logger}->log("Enqueued new timer event $id at position $i: timeout=$event->{timeout} interval=$interval repeating=$repeating\n");
+        $self->{pbot}->{logger}->log("Enqueued new event $id at position $i: timeout=$event->{timeout} interval=$interval repeating=$repeating\n");
     }
 }
 
@@ -267,12 +269,14 @@ sub execute_and_dequeue_event {
     return $self->dequeue_event($id, 1);
 }
 
-sub register {
+# adds event with repeating defaulting to enabled
-    my ($self, $ref, $interval, $id) = @_;
+sub enqueue {
-    $self->enqueue_event($ref, $interval, $id, 1);
+    my ($self, $subref, $interval, $id, $repeating) = @_;
+    $repeating //= 1;
+    $self->enqueue_event($subref, $interval, $id, $repeating);
 }
 
-sub unregister {
+sub dequeue {
     my ($self, $id) = @_;
     $self->dequeue_event($id);
 }
@@ -299,8 +303,11 @@ sub update_interval {
     for (my $i = 0; $i < @{$self->{event_queue}}; $i++) {
         if ($self->{event_queue}->[$i]->{id} eq $id) {
             if ($dont_enqueue) {
+                # update interval in-place without moving event to new place in queue
+                # (allows event to fire at expected time, then updates to new timeout afterwards)
                 $self->{event_queue}->[$i]->{interval} = $interval;
             } else {
+                # remove and add event in new position in queue
                 my $event = splice(@{$self->{event_queue}}, $i, 1);
                 $self->enqueue_event($event->{subref}, $interval, $id, $event->{repeating});
             }
@@ -309,60 +316,57 @@ sub update_interval {
     }
 }
 
-sub waitfor {
+sub duration_until_next_event {
-    my ($self, $duration) = @_;
+    my ($self) = @_;
-    $duration = 1 if $duration < 1;
+    return 0 if not @{$self->{event_queue}};
-    alarm $duration;
+    return $self->{event_queue}->[0]->{timeout} - time;
-    $waitfor = $duration;
 }
 
-sub on_tick_handler {
+# invokes the next event, if ready, and then returns seconds until next event
+
+sub do_next_event {
     my ($self) = @_;
-    return if not $self->{enabled};
 
-    my $debug = $self->{pbot}->{registry}->get_value('timer', 'debug') // 0;
+    # early-return if no events available
-    $self->{pbot}->{logger}->log("$self->{name} tick $seconds\n") if $debug;
+    return 0 if not @{$self->{event_queue}};
 
-    if (@{$self->{event_queue}}) {
+    my $debug = $self->{pbot}->{registry}->get_value('eventqueue', 'debug') // 0;
-        my $next_tick = 1;
-        my @enqueue = ();
-        for (my $i = 0; $i < @{$self->{event_queue}}; $i++) {
-            if ($seconds >= $self->{event_queue}->[$i]->{timeout}) {
-                my $event = $self->{event_queue}->[$i];
-                $self->{pbot}->{logger}->log("Processing timer event $i: $event->{id}\n") if $debug > 1;
-                $event->{subref}->($event);
-                splice @{$self->{event_queue}}, $i--, 1;
-                push @enqueue, $event if $event->{repeating};
-            } else {
-                if ($debug > 2) {
-                    $self->{pbot}->{logger}->log("Event not ready yet: $self->{event_queue}->[$i]->{id} (timeout=$self->{event_queue}->[$i]->{timeout})\n");
-                }
 
-                $next_tick = $self->{event_queue}->[$i]->{timeout} - $seconds;
+    # repeating events to re-enqueue
-                last;
+    my @enqueue;
+
+    for (my $i = 0; $i < @{$self->{event_queue}}; $i++) {
+        # we call time for a fresh time, instead of using a stale $now that
+        # could be well in the past depending on a previous event's duration
+        if (time >= $self->{event_queue}->[$i]->{timeout}) {
+            my $event = $self->{event_queue}->[$i];
+
+            $self->{pbot}->{logger}->log("Processing event $i: $event->{id}\n") if $debug > 1;
+
+            # call event's subref, passing event as argument
+            $event->{subref}->($event);
+
+            # remove event from queue
+            splice @{$self->{event_queue}}, $i--, 1;
+
+            # add event to re-enqueue queue if repeating
+            push @enqueue, $event if $event->{repeating};
+        } else {
+            # no more events ready at this time
+            if ($debug > 2) {
+                $self->{pbot}->{logger}->log("Event not ready yet: $self->{event_queue}->[$i]->{id} (timeout=$self->{event_queue}->[$i]->{timeout})\n");
             }
-        }
 
-        $self->waitfor($next_tick);
+            last;
-
-        foreach my $event (@enqueue) {
-            $self->enqueue_event($event->{subref}, $event->{interval}, $event->{id}, 1);
         }
-    } else {
-        # no queued events, call default overridable on_tick() method if timeout has elapsed
-        if ($seconds - $self->{last} >= $self->{timeout}) {
-            $self->{last} = $seconds;
-            $self->on_tick;
-        }
-
-        $self->waitfor($self->{timeout} - $seconds - $self->{last});
     }
-}
 
-# default overridable handler, executed whenever timeout is triggered
+    # re-enqueue repeating events
-sub on_tick {
+    foreach my $event (@enqueue) {
-    my ($self) = @_;
+        $self->enqueue_event($event->{subref}, $event->{interval}, $event->{id}, 1);
-    $self->{pbot}->{logger}->log("Tick! $self->{name} $self->{timeout} $self->{last} $seconds\n");
+    }
+
+    return $self->duration_until_next_event;
 }
 
 1;

PBot/IRCHandlers.pm

@@ -64,7 +64,8 @@ sub initialize {
     $self->{pbot}->{event_dispatcher}->register_handler('pbot.join', sub { $self->on_self_join(@_) });
     $self->{pbot}->{event_dispatcher}->register_handler('pbot.part', sub { $self->on_self_part(@_) });
 
-    $self->{pbot}->{timer}->register(sub { $self->check_pending_whos }, 10, 'Check Pending Whos');
+    # TODO: enqueue these events as needed instead of naively checking every 10 seconds
+    $self->{pbot}->{event_queue}->enqueue(sub { $self->check_pending_whos }, 10, 'Check pending WHOs');
 }
 
 sub default_handler {

PBot/IgnoreList.pm

@@ -98,7 +98,7 @@ sub enqueue_ignores {
             my $interval = $timeout - $now;
             $interval = 0 if $interval < 0;
 
-            $self->{pbot}->{timer}->enqueue_event(sub {
+            $self->{pbot}->{event_queue}->enqueue_event(sub {
                     $self->remove($channel, $hostmask);
                 }, $interval, "ignore_timeout $channel $hostmask"
             );
@@ -136,9 +136,9 @@ sub add {
     $self->{ignorelist}->add($channel, $hostmask, $data);
 
     if ($length > 0) {
-        $self->{pbot}->{timer}->dequeue_event("ignore_timeout $channel $hostmask");
+        $self->{pbot}->{event_queue}->dequeue_event("ignore_timeout $channel $hostmask");
 
-        $self->{pbot}->{timer}->enqueue_event(sub {
+        $self->{pbot}->{event_queue}->enqueue_event(sub {
                 $self->remove($channel, $hostmask);
             }, $length, "ignore_timeout $channel $hostmask"
         );
@@ -159,7 +159,7 @@ sub remove {
 
     $channel = '.*' if $channel !~ /^#/;
 
-    $self->{pbot}->{timer}->dequeue_event("ignore_timeout $channel $hostmask");
+    $self->{pbot}->{event_queue}->dequeue_event("ignore_timeout $channel $hostmask");
     return $self->{ignorelist}->remove($channel, $hostmask);
 }
 

PBot/Interpreter.pm

@@ -887,7 +887,7 @@ sub output_result {
 sub add_message_to_output_queue {
     my ($self, $channel, $message, $delay) = @_;
 
-    $self->{pbot}->{timer}->enqueue_event(
+    $self->{pbot}->{event_queue}->enqueue_event(
         sub {
             my $context = {
                 from       => $channel,
@@ -909,7 +909,7 @@ sub add_message_to_output_queue {
 sub add_to_command_queue {
     my ($self, $channel, $command, $delay, $repeating) = @_;
 
-    $self->{pbot}->{timer}->enqueue_event(
+    $self->{pbot}->{event_queue}->enqueue_event(
         sub {
             my $context = {
                 from                => $channel,

PBot/LagChecker.pm

@@ -45,8 +45,8 @@ sub initialize {
     # registry trigger for lag_history_interval changes
     $self->{pbot}->{registry}->add_trigger('lagchecker', 'lag_history_interval', sub { $self->trigger_lag_history_interval(@_) });
 
-    # timer to send PINGs
+    # enqueue repeating event  to send PINGs
-    $self->{pbot}->{timer}->register(
+    $self->{pbot}->{event_queue}->enqueue(
         sub { $self->send_ping },
         $self->{pbot}->{registry}->get_value('lagchecker', 'lag_history_interval'),
         'lag check'
@@ -62,7 +62,7 @@ sub initialize {
 # registry trigger fires when value changes
 sub trigger_lag_history_interval {
     my ($self, $section, $item, $newvalue) = @_;
-    $self->{pbot}->{timer}->update_interval('lag check', $newvalue);
+    $self->{pbot}->{event_queue}->update_interval('lag check', $newvalue);
 }
 
 # lagcheck bot command

PBot/MessageHistory_SQLite.pm

@@ -35,7 +35,7 @@ sub initialize {
     $self->{pbot}->{registry}->add_trigger('messagehistory', 'sqlite_commit_interval', sub { $self->sqlite_commit_interval_trigger(@_) });
     $self->{pbot}->{registry}->add_trigger('messagehistory', 'sqlite_debug',           sub { $self->sqlite_debug_trigger(@_) });
 
-    $self->{pbot}->{timer}->register(
+    $self->{pbot}->{event_queue}->enqueue(
         sub { $self->commit_message_history },
         $self->{pbot}->{registry}->get_value('messagehistory', 'sqlite_commit_interval'),
         'messagehistory commit'
@@ -47,7 +47,7 @@ sub initialize {
 
 sub sqlite_commit_interval_trigger {
     my ($self, $section, $item, $newvalue) = @_;
-    $self->{pbot}->{timer}->update_interval('messagehistory commit', $newvalue);
+    $self->{pbot}->{event_queue}->update_interval('messagehistory commit', $newvalue);
 }
 
 sub sqlite_debug_trigger {

PBot/MiscCommands.pm

@@ -191,8 +191,8 @@ sub cmd_reload {
         },
 
         'banlist' => sub {
-            $self->{pbot}->{timer}->dequeue_event('unban #.*');
+            $self->{pbot}->{event_queue}->dequeue_event('unban #.*');
-            $self->{pbot}->{timer}->dequeue_event('unmute #.*');
+            $self->{pbot}->{event_queue}->dequeue_event('unmute #.*');
             $self->{pbot}->{banlist}->{banlist}->load;
             $self->{pbot}->{banlist}->{quietlist}->load;
             $self->{pbot}->{banlist}->enqueue_timeouts($self->{pbot}->{banlist}->{banlist},   'b');

PBot/PBot.pm

@@ -37,6 +37,7 @@ use PBot::ChanOps;
 use PBot::DualIndexHashObject;
 use PBot::DualIndexSQLiteObject;
 use PBot::EventDispatcher;
+use PBot::EventQueue;
 use PBot::Factoids;
 use PBot::Functions;
 use PBot::HashObject;
@@ -55,7 +56,6 @@ use PBot::Registry;
 use PBot::Refresher;
 use PBot::SelectHandler;
 use PBot::StdinReader;
-use PBot::Timer;
 use PBot::Updater;
 use PBot::Users;
 use PBot::Utils::ParseDate;
@@ -178,7 +178,7 @@ sub initialize {
     $self->{irc} = PBot::IRC->new;
 
     # prepare remaining core PBot modules -- do not change this order
-    $self->{timer}            = PBot::Timer->new(pbot => $self, timeout => 10, name => 'PBot Timer', %conf);
+    $self->{event_queue}      = PBot::EventQueue->new(pbot => $self, name => 'PBot event queue', %conf);
     $self->{event_dispatcher} = PBot::EventDispatcher->new(pbot => $self, %conf);
     $self->{users}            = PBot::Users->new(pbot => $self, filename => "$conf{data_dir}/users", %conf);
     $self->{antiflood}        = PBot::AntiFlood->new(pbot => $self, %conf);
@@ -213,9 +213,9 @@ sub initialize {
     # -- this must happen last after all modules have registered their capabilities --
     $self->{capabilities}->rebuild_botowner_capabilities;
 
-    # flush all pending save events to disk at exit
+    # fire all pending save events at exit
     $self->{atexit}->register(sub {
-            $self->{timer}->execute_and_dequeue_event('save *');
+            $self->{event_queue}->execute_and_dequeue_event('save .*');
             return;
         }
     );
@@ -267,9 +267,6 @@ sub connect {
 
     $self->{connected} = 1;
 
-    # start timer once connected
-    $self->{timer}->start;
-
     # set up handlers for the IRC engine
     $self->{conn}->add_default_handler(sub { $self->{irchandlers}->default_handler(@_) }, 1);
     $self->{conn}->add_handler([251, 252, 253, 254, 255, 302], sub { $self->{irchandlers}->on_init(@_) });
@@ -308,7 +305,6 @@ sub register_signal_handlers {
 sub atexit {
     my $self = shift;
     $self->{atexit}->execute_all;
-    alarm 0;
     if (exists $self->{logger}) {
         $self->{logger}->log("Good-bye.\n");
     } else {
@@ -335,7 +331,16 @@ sub exit {
 # main loop
 sub do_one_loop {
     my ($self) = @_;
-    $self->{irc}->do_one_loop();
+
+    # do an irc engine loop (select, eventqueues, etc)
+    $self->{irc}->do_one_loop;
+
+    # check for an available PBot event (returns seconds until next event)
+    my $waitfor = $self->{event_queue}->do_next_event;
+
+    # tell irc select loop to sleep for this many seconds
+    # (or until its own internal eventqueue has an event)
+    $self->{irc}->timeout($waitfor);
 }
 
 # main entry point

PBot/ProcessManager.pm

@@ -243,13 +243,12 @@ sub execute_process {
         # remove atexit handlers
         $self->{pbot}->{atexit}->unregister_all;
 
-        # FIXME: close databases and files too? Or just set everything to check for $self->{pbot}->{child} == 1 or $context->{pid} == 0?
-
         # execute the provided subroutine, results are stored in $context
         eval {
             local $SIG{ALRM} = sub { die "Process `$context->{commands}->[0]` timed-out" };
             alarm $timeout;
             $subref->($context);
+            alarm 0;
         };
 
         # check for errors
@@ -265,9 +264,6 @@ sub execute_process {
             $context->{result} =~ s/\s+...propagated at .*$//ms;
         }
 
-        # turn alarm back on for PBot::Timer
-        alarm 1;
-
         # print $context to pipe
         my $json = encode_json $context;
         print $writer "$json\n";

PBot/WebPaste.pm

@@ -82,8 +82,6 @@ sub paste {
 
     $result =~ s/^\s+|\s+$//g;
 
-    alarm 1; # LWP::UserAgent::Paranoid kills alarm
-
     return $result;
 }
 

Plugins/AntiRepeat.pm

@@ -26,7 +26,7 @@ sub initialize {
 
 sub unload {
     my $self = shift;
-    $self->{pbot}->{timer}->dequeue_event('antirepeat .*');
+    $self->{pbot}->{event_queue}->dequeue_event('antirepeat .*');
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.public');
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.caction');
 }
@@ -112,7 +112,7 @@ sub on_public {
             $self->{offenses}->{$account}->{$channel}->{last_offense} = gettimeofday;
             $self->{offenses}->{$account}->{$channel}->{offenses}++;
 
-            $self->{pbot}->{timer}->enqueue_event(sub {
+            $self->{pbot}->{event_queue}->enqueue_event(sub {
                     my ($event) = @_;
                     $self->{offenses}->{$account}->{$channel}->{offenses}--;
 

Plugins/AntiTwitter.pm

@@ -24,7 +24,7 @@ sub initialize {
 sub unload {
     my ($self) = @_;
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.public');
-    $self->{pbot}->{timer}->dequeue_event('antitwitter .*');
+    $self->{pbot}->{event_queue}->dequeue_event('antitwitter .*');
 }
 
 sub on_public {
@@ -68,7 +68,7 @@ sub on_public {
                     );
                     $self->{pbot}->{chanops}->gain_ops($channel);
 
-                    $self->{pbot}->{timer}->enqueue_event(sub {
+                    $self->{pbot}->{event_queue}->enqueue_event(sub {
                             my ($event) = @_;
                             if (--$self->{offenses}->{$channel}->{$nick}->{offenses} <= 0) {
                                 delete $self->{offenses}->{$channel}->{$nick};

Plugins/Battleship.pm

@@ -34,7 +34,7 @@ sub initialize {
 sub unload {
     my $self = shift;
     $self->{pbot}->{commands}->unregister('battleship');
-    $self->{pbot}->{timer}->dequeue_event('battleship loop');
+    $self->{pbot}->{event_queue}->dequeue_event('battleship loop');
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.part');
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.quit');
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.kick');
@@ -124,7 +124,7 @@ sub cmd_battleship {
                 $player = {id => -1, name => undef, missedinputs => 0};
                 push @{$self->{state_data}->{players}}, $player;
 
-                $self->{pbot}->{timer}->enqueue_event(sub {
+                $self->{pbot}->{event_queue}->enqueue_event(sub {
                         $self->run_one_state;
                     }, 1, 'battleship loop', 1
                 );
@@ -147,7 +147,7 @@ sub cmd_battleship {
             $player = {id => $id, name => $challengee, missedinputs => 0};
             push @{$self->{state_data}->{players}}, $player;
 
-            $self->{pbot}->{timer}->enqueue_event(sub {
+            $self->{pbot}->{event_queue}->enqueue_event(sub {
                     $self->battleship_loop;
                 }, 1, 'battleship loop', 1
             );
@@ -965,7 +965,7 @@ sub show_battlefield {
 sub nogame {
     my ($self, $state) = @_;
     $state->{result} = 'nogame';
-    $self->{pbot}->{timer}->update_repeating('battleship loop', 0);
+    $self->{pbot}->{event_queue}->update_repeating('battleship loop', 0);
     return $state;
 }
 

Plugins/Connect4.pm

@@ -32,7 +32,7 @@ sub unload {
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.part');
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.quit');
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.kick');
-    $self->{pbot}->{timer}->dequeue_event('connect4 loop');
+    $self->{pbot}->{event_queue}->dequeue_event('connect4 loop');
 }
 
 sub on_kick {
@@ -156,7 +156,7 @@ sub cmd_connect4 {
                 $self->{current_state} = 'accept';
                 $self->{state_data}    = {players => [], counter => 0};
 
-                $self->{pbot}->{timer}->enqueue_event(
+                $self->{pbot}->{event_queue}->enqueue_event(
                     sub {
                         $self->run_one_state;
                     }, 1, 'connect4 loop', 1
@@ -185,7 +185,7 @@ sub cmd_connect4 {
             $self->{current_state} = 'accept';
             $self->{state_data}    = {players => [], counter => 0};
 
-            $self->{pbot}->{timer}->enqueue_event(
+            $self->{pbot}->{event_queue}->enqueue_event(
                 sub {
                     $self->run_one_state;
                 }, 1, 'connect4 loop', 1
@@ -693,7 +693,7 @@ sub show_board {
 sub nogame {
     my ($self, $state) = @_;
     $state->{result} = 'nogame';
-    $self->{pbot}->{timer}->update_repeating('connect4 loop', 0);
+    $self->{pbot}->{event_queue}->update_repeating('connect4 loop', 0);
     return $state;
 }
 

Plugins/RelayUnreg.pm

@@ -14,12 +14,12 @@ sub initialize {
     $self->{pbot}->{event_dispatcher}->register_handler('irc.public', sub { $self->on_public(@_) });
     $self->{queue}    = [];
     $self->{notified} = {};
-    $self->{pbot}->{timer}->register(sub { $self->check_queue }, 1, 'RelayUnreg');
+    $self->{pbot}->{event_queue}->enqueue(sub { $self->check_queue }, 1, 'RelayUnreg');
 }
 
 sub unload {
     my $self = shift;
-    $self->{pbot}->{timer}->unregister('RelayUnreg');
+    $self->{pbot}->{event_queue}->dequeue('RelayUnreg');
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.public');
 }
 

Plugins/RemindMe.pm

@@ -25,7 +25,7 @@ sub unload {
     my $self = shift;
     $self->dbi_end;
     $self->{pbot}->{commands}->unregister('remindme');
-    $self->{pbot}->{timer}->dequeue_event('reminder .*');
+    $self->{pbot}->{event_queue}->dequeue_event('reminder .*');
 }
 
 sub enqueue_reminders {
@@ -56,7 +56,7 @@ sub enqueue_reminders {
         $timeout = 10 if $timeout < 10;
         my $repeating = $reminder->{repeat};
 
-        $self->{pbot}->{timer}->enqueue_event(
+        $self->{pbot}->{event_queue}->enqueue_event(
             sub {
                 my ($event) = @_;
                 $self->do_reminder($reminder->{id}, $event);
@@ -126,7 +126,7 @@ sub add_reminder {
         return 0;
     }
 
-    $self->{pbot}->{timer}->enqueue_event(
+    $self->{pbot}->{event_queue}->enqueue_event(
         sub {
             my ($event) = @_;
             $self->do_reminder($id, $event);
@@ -151,7 +151,7 @@ sub delete_reminder {
         return 0;
     }
 
-    $self->{pbot}->{timer}->dequeue_event("reminder $id");
+    $self->{pbot}->{event_queue}->dequeue_event("reminder $id");
     return 1;
 }
 

Plugins/Spinach.pm

@@ -67,7 +67,7 @@ sub initialize {
 sub unload {
     my $self = shift;
     $self->{pbot}->{commands}->unregister('spinach');
-    $self->{pbot}->{timer}->dequeue_event('spinach loop');
+    $self->{pbot}->{event_queue}->dequeue_event('spinach loop');
     $self->{stats}->end if $self->{stats_running};
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.part');
     $self->{pbot}->{event_dispatcher}->remove_handler('irc.quit');
@@ -336,7 +336,7 @@ sub cmd_spinach {
                 $self->{state_data}    = { players => [], counter => 0 };
                 $self->{current_state} = 'getplayers';
 
-                $self->{pbot}->{timer}->enqueue_event(sub {
+                $self->{pbot}->{event_queue}->enqueue_event(sub {
                         $self->run_one_state;
                     }, 1, 'spinach loop', 1
                 );
@@ -409,7 +409,7 @@ sub cmd_spinach {
 
                 if (not @{$self->{state_data}->{players}}) {
                     $self->{current_state} = 'nogame';
-                    $self->{pbot}->{timer}->update_repeating('spinach loop', 0);
+                    $self->{pbot}->{event_queue}->update_repeating('spinach loop', 0);
                     return "/msg $self->{channel} $context->{nick} has left the game! All players have left. The game has been stopped.";
                 } else {
                     return "/msg $self->{channel} $context->{nick} has left the game!";
@@ -935,7 +935,7 @@ sub run_one_state {
         if (not @{$self->{state_data}->{players}}) {
             $self->send_message($self->{channel}, "All players have left the game!");
             $self->{current_state} = 'nogame';
-            $self->{pbot}->{timer}->update_repeating('spinach loop', 0);
+            $self->{pbot}->{event_queue}->update_repeating('spinach loop', 0);
         }
     }
 
@@ -945,7 +945,7 @@ sub run_one_state {
     if (not defined $self->{current_state}) {
         $self->{pbot}->{logger}->log("Spinach state broke.\n");
         $self->{current_state} = 'nogame';
-        $self->{pbot}->{timer}->update_repeating('spinach loop', 0);
+        $self->{pbot}->{event_queue}->update_repeating('spinach loop', 0);
         return;
     }
 
@@ -2152,7 +2152,7 @@ sub nogame {
         delete $self->{stats_running};
     }
     $state->{result} = 'nogame';
-    $self->{pbot}->{timer}->update_repeating('spinach loop', 0);
+    $self->{pbot}->{event_queue}->update_repeating('spinach loop', 0);
     return $state;
 }
 
@@ -2205,7 +2205,7 @@ sub getplayers {
                 $self->send_message($self->{channel}, "All players have left the queue. The game has been stopped.");
                 $self->{current_state} = 'nogame';
                 $self->{result}        = 'nogame';
-                $self->{pbot}->{timer}->update_repeating('spinach loop', 0);
+                $self->{pbot}->{event_queue}->update_repeating('spinach loop', 0);
                 return $state;
             }
         }