use IO::Select;
use Time::HiRes qw(time);
-use Object::Remote::Logging qw( :log :dlog );
+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 });
my $fh = $watch{handle};
Dlog_debug { "Adding IO watch for $_" } $fh;
- #TODO if this works out non-blocking support
- #will need to be integrated in a way that
- #is compatible with Windows which has no
- #non-blocking support - see also ::ReadChannel
- if (0) {
- Dlog_warn { "setting file handle to be non-blocking: $_" } $fh;
- use Fcntl qw(F_GETFL F_SETFL O_NONBLOCK);
- my $flags = fcntl($fh, F_GETFL, 0)
- or die "Can't get flags for the socket: $!\n";
- $flags = fcntl($fh, F_SETFL, $flags | O_NONBLOCK)
- or die "Can't set flags for the socket: $!\n";
- }
-
if (my $cb = $watch{on_read_ready}) {
log_trace { "IO watcher is registering with select for reading" };
$self->_read_select->add($fh);
sub _sort_timers {
my ($self, @new) = @_;
- my $timers = $self->_timers;
-
+ my $timers = $self->_timers;
+
log_trace { "Sorting timers" };
-
+
@{$timers} = sort { $a->[0] <=> $b->[0] } @{$timers}, @new;
- return;
+ return;
}
sub watch_time {
my ($self, %watch) = @_;
- my $at;
-
+ 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};
+ $at = time() + $watch{after};
} elsif (exists($watch{at})) {
- $at = $watch{at};
+ $at = $watch{at};
} else {
- die "watch_time requires every, after or at";
+ 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 that expires at '$at'" };
+ $self->_sort_timers($new);
+ log_debug { "Created new timer with id '$new' that expires at '$at'" };
return "$new";
}
sub unwatch_time {
my ($self, $id) = @_;
- log_debug { "Removing timer with id of '$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;
- #undef means no timeout, select only returns
- #when data is ready - when the system
- #deadlocks the chatter from the timeout in
- #select clogs up the logs
- #TODO should make this an attribute
- my $delay_max = undef;
-
+ 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 " };
-
+ log_trace { "next timer fires in '$duration' seconds" };
+
if ($duration < 0) {
- $duration = 0;
+ $duration = 0;
} elsif (defined $delay_max && $duration > $delay_max) {
$duration = $delay_max;
}
-
- return $duration;
+
+ return $duration;
}
sub loop_once {
my ($self) = @_;
my $read = $self->_read_watches;
my $write = $self->_write_watches;
- our $Loop_Entered = 1;
my $read_count = 0;
- my $write_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' ) };
- #TODO The docs state that select() in some instances can return a socket as ready to
- #read data even if reading from it would block and the recomendation is to set
- #handles used with select() as non-blocking but Perl on Windows can not set a
- #handle to use non-blocking IO - If Windows is not one of the operating
- #systems where select() returns a handle that could block it would work to
- #enable non-blocking mode only under Posix - the non-blocking sysread()
- #logic would work unmodified for both blocking and non-blocking handles
- #under Posix and Windows.
+ 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(
- #TODO how come select() isn't used to identify handles with errors on them?
- #TODO is there a specific reason for a half second maximum wait duration?
- #The two places I've found for the runloop to be invoked don't return control
- #to the caller until a controlling variable interrupts the loop that invokes
- #loop_once() - is this to allow that variable to be polled and exit the
- #run loop? If so why isn't that behavior event driven and causes select() to
- #return?
$self->_read_select, $self->_write_select, undef, $wait_time
- );
- log_trace {
+ );
+ 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";
# differentiate between an error and a timeout.
# -- no, love, mst.
- local $Loop_Entered;
-
- log_trace { "Reading from all ready filehandles" };
+ log_trace { "Reading from ready filehandles" };
foreach my $fh (@$readable) {
next unless $read->{$fh};
$read_count++;
$read->{$fh}();
- last if $Loop_Entered;
+ #FIXME this is a rough workaround for race conditions that can cause deadlocks
+ #under load
+ last;
}
- log_trace { "Writing to all ready filehandles" };
+ log_trace { "Writing to ready filehandles" };
foreach my $fh (@$writeable) {
next unless $write->{$fh};
$write_count++;
$write->{$fh}();
- last if $Loop_Entered;
+ #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_debug { "Found timer that needs to be executed: $_" } $active;
-# my (shift @$timers)->[1]->();
-
+ 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];
+ $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);
+ #it doesn't repeat again so get rid of it
+ shift(@$timers);
}
#execute the timer
$active->[1]->();
-
- last if $Loop_Entered;
}
-
+
log_trace { "Run loop: single loop is completed" };
return;
}
-#::Node and ::ConnectionServer use the want_run() / want_stop()
-#counter to cause a run-loop to execute while something is active;
-#the futures do this via a different mechanism
sub want_run {
my ($self) = @_;
- Dlog_debug { "Run loop: Incrimenting want_running, is now $_" }
+ Dlog_debug { "Run loop: Incremeting want_running, is now $_" }
++$self->{want_running};
}
my ($self) = @_;
if (! $self->{want_running}) {
log_debug { "Run loop: want_stop() was called but want_running was not true" };
- return;
+ return;
}
Dlog_debug { "Run loop: decrimenting want_running, is now $_" }
--$self->{want_running};
}
-#TODO Hypothesis: Futures invoke run() which gives that future
-#it's own localized is_running attribute - any adjustment to the
-#is_running attribute outside of that future will not effect that
-#future so each future winds up able to call run() and stop() at
-#will with out interfering with each other - how about having
-#run loop until the future becomes ready?
sub run {
my ($self) = @_;
log_trace { "Run loop: run() invoked" };
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