package Object::Remote::MiniLoop;
use IO::Select;
+use Time::HiRes qw(time);
+use Object::Remote::Logging qw( :log :dlog );
use Moo;
# this is ro because we only actually set it using local in sub run
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;
+
+ #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);
$self->_read_watches->{$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 watch_time {
+ my ($self, %watch) = @_;
+ my $at = $watch{at} || do {
+ die "watch_time requires at or after" unless my $after = $watch{after};
+ time() + $after;
+ };
+ die "watch_time requires code" unless my $code = $watch{code};
+ my $timers = $self->_timers;
+ my $new = [ $at => $code ];
+ @{$timers} = sort { $a->[0] <=> $b->[0] } @{$timers}, $new;
+ log_debug { "Created new timer that expires at '$at'" };
+ return "$new";
+}
+
+sub unwatch_time {
+ my ($self, $id) = @_;
+ log_debug { "Removing timer with id of '$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;
+
+ 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;
+ our $Loop_Entered = 1;
+ 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 ? $wait_time : 'indefinite' ) };
+ #TODO The docs state that select() in some instances can return a socket as ready to
+ #read data even if reading from it would block and the recomendation is to set
+ #handles used with select() as non-blocking but Perl on Windows can not set a
+ #handle to use non-blocking IO - If Windows is not one of the operating
+ #systems where select() returns a handle that could block it would work to
+ #enable non-blocking mode only under Posix - the non-blocking sysread()
+ #logic would work unmodified for both blocking and non-blocking handles
+ #under Posix and Windows.
+ my ($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 {
+ 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.
+
+ local $Loop_Entered;
+
+ log_trace { "Reading from all ready filehandles" };
foreach my $fh (@$readable) {
+ next unless $read->{$fh};
+ $read_count++;
$read->{$fh}();
+ last if $Loop_Entered;
}
+ log_trace { "Writing to all ready filehandles" };
+ foreach my $fh (@$writeable) {
+ next unless $write->{$fh};
+ $write_count++;
+ $write->{$fh}();
+ last if $Loop_Entered;
+ }
+
+ 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) {
+ Dlog_debug { "Found timer that needs to be executed: $_" } $timers->[0];
+ (shift @$timers)->[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) = @_;
- $self->{want_running}++;
+ Dlog_debug { "Run loop: Incrimenting 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};
}
+#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" };
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