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=5f22eac83951d6e363040bb2f1eeee43c4b523be;hp=3951bf9d3eb4701f9e8b6cc708706da121072775;hb=901159798e5541050b7c3357a7148818610a4019;hpb=498c4ad5b1cc2db13c7b581b44ff3f6b9e33eaba

diff --git a/lib/Object/Remote/MiniLoop.pm b/lib/Object/Remote/MiniLoop.pm
index 3951bf9..5f22eac 100644
--- a/lib/Object/Remote/MiniLoop.pm
+++ b/lib/Object/Remote/MiniLoop.pm
@@ -2,6 +2,7 @@ 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
@@ -18,6 +19,7 @@ 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 => $fh,
@@ -35,11 +37,26 @@ sub pass_watches_to {
 sub watch_io {
   my ($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
+  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} = $cb;
   }
@@ -49,11 +66,14 @@ sub watch_io {
 sub unwatch_io {
   my ($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};
   }
@@ -70,61 +90,145 @@ sub watch_time {
   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;
+  }
+  
+  #uncomment for original behavior
+  #return .5;    
+  return $duration; 
+}
+
 sub loop_once {
   my ($self) = @_;
   my $read = $self->_read_watches;
   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_debug {  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(
-    $self->_read_select, $self->_write_select, undef, 0.5
-  );
+    #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_debug { 
+    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 all ready filehandles" };
   foreach my $fh (@$readable) {
-    $read->{$fh}() if $read->{$fh};
+    next unless $read->{$fh};
+    $read_count++;
+    $read->{$fh}();
+#    $read->{$fh}() if $read->{$fh};
   }
+  log_trace { "Writing to all ready filehandles" };
   foreach my $fh (@$writeable) {
-    $write->{$fh}() if $write->{$fh};
+    next unless $write->{$fh};
+    $write_count++;
+    $write->{$fh}();
+#    $write->{$fh}() if $write->{$fh};
   }
+  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]->();
   }
+  log_debug { "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 
 sub run {
   my ($self) = @_;
+  log_info { "Run loop: run() invoked" };
   local $self->{is_running} = 1;
   while ($self->is_running) {
     $self->loop_once;
   }
+  log_info { "Run loop: run() completed" };
   return;
 }