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) = @_;
+ 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) = @_;
+ 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;
projects / scpubgit/Object-Remote.git / blobdiff