X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=scpubgit%2FObject-Remote.git;a=blobdiff_plain;f=lib%2FObject%2FRemote%2FMiniLoop.pm;h=7e673ca5c623f1c9d9c5ac4d05c2c90cc664555e;hp=b74619c83fae571cd564d171bbb5f1ad63e50205;hb=bef36e73e4257b2ba8e59eb55661ffc51d8a620a;hpb=6c597351edfa3ed86fc06b7be3165b334bf93784

diff --git a/lib/Object/Remote/MiniLoop.pm b/lib/Object/Remote/MiniLoop.pm
index b74619c..7e673ca 100644
--- a/lib/Object/Remote/MiniLoop.pm
+++ b/lib/Object/Remote/MiniLoop.pm
@@ -1,76 +1,245 @@
 package Object::Remote::MiniLoop;
 
 use IO::Select;
+use Time::HiRes qw(time);
+use Object::Remote::Logging qw( :log :dlog router );
 use Moo;
 
-# this is ro because we only actually set it using local in sub run
+BEGIN {
+  $SIG{PIPE} = sub { log_debug { "Got a PIPE signal" } };
+
+  router()->exclude_forwarding
+}
 
+# this is ro because we only actually set it using local in sub run
 has is_running => (is => 'ro', clearer => 'stop');
+#maximum duration that select() will block - undef means indefinite,
+#0 means no blocking, otherwise maximum time in seconds
+has block_duration => ( is => 'rw' );
 
 has _read_watches => (is => 'ro', default => sub { {} });
 has _read_select => (is => 'ro', default => sub { IO::Select->new });
 
+has _write_watches => (is => 'ro', default => sub { {} });
+has _write_select => (is => 'ro', default => sub { IO::Select->new });
+
+has _timers => (is => 'ro', default => sub { [] });
+
 sub pass_watches_to {
   my ($self, $new_loop) = @_;
+  log_debug { "passing watches to new run loop" };
   foreach my $fh ($self->_read_select->handles) {
     $new_loop->watch_io(
       handle => $fh,
       on_read_ready => $self->_read_watches->{$fh}
     );
   }
+  foreach my $fh ($self->_write_select->handles) {
+    $new_loop->watch_io(
+      handle => $fh,
+      on_write_ready => $self->_write_watches->{$fh}
+    );
+  }
 }
 
 sub watch_io {
   my ($self, %watch) = @_;
   my $fh = $watch{handle};
+  Dlog_debug { "Adding IO watch for $_" } $fh;
+
   if (my $cb = $watch{on_read_ready}) {
+    log_trace { "IO watcher is registering with select for reading" };
     $self->_read_select->add($fh);
     $self->_read_watches->{$fh} = $cb;
   }
+  if (my $cb = $watch{on_write_ready}) {
+    log_trace { "IO watcher is registering with select for writing" };
+    $self->_write_select->add($fh);
+    $self->_write_watches->{$fh} = $cb;
+  }
+  return;
 }
 
 sub unwatch_io {
   my ($self, %watch) = @_;
   my $fh = $watch{handle};
+  Dlog_debug { "Removing IO watch for $_" } $fh;
   if ($watch{on_read_ready}) {
+    log_trace { "IO watcher is removing read from select()" };
     $self->_read_select->remove($fh);
     delete $self->_read_watches->{$fh};
   }
+  if ($watch{on_write_ready}) {
+    log_trace { "IO watcher is removing write from select()" };
+    $self->_write_select->remove($fh);
+    delete $self->_write_watches->{$fh};
+  }
+  return;
+}
+
+sub _sort_timers {
+  my ($self, @new) = @_;
+  my $timers = $self->_timers;
+
+  log_trace { "Sorting timers" };
+
+  @{$timers} = sort { $a->[0] <=> $b->[0] } @{$timers}, @new;
+  return;
+}
+
+sub watch_time {
+  my ($self, %watch) = @_;
+  my $at;
+
+  Dlog_trace { "watch_time() invoked with $_" } \%watch;
+
+  if (exists($watch{every})) {
+    $at = time() + $watch{every};
+  } elsif (exists($watch{after})) {
+    $at = time() + $watch{after};
+  } elsif (exists($watch{at})) {
+    $at = $watch{at};
+  } else {
+    die "watch_time requires every, after or at";
+  }
+
+  die "watch_time requires code" unless my $code = $watch{code};
+  my $timers = $self->_timers;
+  my $new = [ $at => $code, $watch{every} ];
+  $self->_sort_timers($new);
+  log_debug { "Created new timer with id '$new' that expires at '$at'" };
+  return "$new";
+}
+
+sub unwatch_time {
+  my ($self, $id) = @_;
+  log_trace { "Removing timer with id of '$id'" };
+  @$_ = grep !($_ eq $id), @$_ for $self->_timers;
+  return;
+}
+
+sub _next_timer_expires_delay {
+  my ($self) = @_;
+  my $timers = $self->_timers;
+  my $delay_max = $self->block_duration;
+
+  return $delay_max unless @$timers;
+  my $duration = $timers->[0]->[0] - time;
+
+  log_trace { "next timer fires in '$duration' seconds" };
+
+  if ($duration < 0) {
+    $duration = 0;
+  } elsif (defined $delay_max && $duration > $delay_max) {
+    $duration = $delay_max;
+  }
+
+  return $duration;
 }
 
 sub loop_once {
   my ($self) = @_;
   my $read = $self->_read_watches;
-  my ($readable) = IO::Select->select($self->_read_select, undef, undef, 0.5);
+  my $write = $self->_write_watches;
+  my $read_count = 0;
+  my $write_count = 0;
+  my @c = caller;
+  my $wait_time = $self->_next_timer_expires_delay;
+  log_trace {
+    sprintf("Run loop: loop_once() has been invoked by $c[1]:$c[2] with read:%i write:%i select timeout:%s",
+      scalar(keys(%$read)), scalar(keys(%$write)), defined $wait_time ? $wait_time : 'indefinite' )
+  };
+  my ($readable, $writeable) = IO::Select->select(
+    $self->_read_select, $self->_write_select, undef, $wait_time
+  );
+  log_trace {
+    my $readable_count = defined $readable ? scalar(@$readable) : 0;
+    my $writable_count = defined $writeable ? scalar(@$writeable) : 0;
+    "Run loop: select returned readable:$readable_count writeable:$writable_count";
+  };
   # I would love to trap errors in the select call but IO::Select doesn't
   # differentiate between an error and a timeout.
   #   -- no, love, mst.
+
+  log_trace { "Reading from ready filehandles" };
   foreach my $fh (@$readable) {
+    next unless $read->{$fh};
+    $read_count++;
     $read->{$fh}();
+    #FIXME this is a rough workaround for race conditions that can cause deadlocks
+    #under load
+    last;
+  }
+  log_trace { "Writing to ready filehandles" };
+  foreach my $fh (@$writeable) {
+    next unless $write->{$fh};
+    $write_count++;
+    $write->{$fh}();
+    #FIXME this is a rough workaround for race conditions that can cause deadlocks
+    #under load
+    last;
+  }
+
+  #moving the timers above the read() section exposes a deadlock
+  log_trace { "Read from $read_count filehandles; wrote to $write_count filehandles" };
+  my $timers = $self->_timers;
+  my $now = time();
+  log_trace { "Checking timers" };
+  while (@$timers and $timers->[0][0] <= $now) {
+    my $active = $timers->[0];
+    Dlog_trace { "Found timer that needs to be executed: '$active'" };
+
+    if (defined($active->[2])) {
+      #handle the case of an 'every' timer
+      $active->[0] = time() + $active->[2];
+      Dlog_trace { "scheduling timer for repeat execution at $_"} $active->[0];
+      $self->_sort_timers;
+    } else {
+      #it doesn't repeat again so get rid of it
+      shift(@$timers);
+    }
+
+    #execute the timer
+    $active->[1]->();
   }
+
+  log_trace { "Run loop: single loop is completed" };
+  return;
 }
 
 sub want_run {
   my ($self) = @_;
-  $self->{want_running}++;
+  Dlog_debug { "Run loop: Incremeting want_running, is now $_" }
+    ++$self->{want_running};
 }
 
 sub run_while_wanted {
   my ($self) = @_;
+  log_debug { my $wr = $self->{want_running}; "Run loop: run_while_wanted() invoked; want_running: $wr" };
   $self->loop_once while $self->{want_running};
+  log_debug { "Run loop: run_while_wanted() completed" };
+  return;
 }
 
 sub want_stop {
   my ($self) = @_;
-  $self->{want_running}-- if $self->{want_running};
+  if (! $self->{want_running}) {
+    log_debug { "Run loop: want_stop() was called but want_running was not true" };
+    return;
+  }
+  Dlog_debug { "Run loop: decrimenting want_running, is now $_" }
+    --$self->{want_running};
 }
 
 sub run {
   my ($self) = @_;
+  log_trace { "Run loop: run() invoked" };
   local $self->{is_running} = 1;
   while ($self->is_running) {
     $self->loop_once;
   }
+  log_trace { "Run loop: run() completed" };
+  return;
 }
 
 1;