X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FObject%2FRemote%2FMiniLoop.pm;h=c23bfa185f7f141785da8cc966114d89b8391e7c;hb=9031635d18e754da303557b656c63ce8e7eb8e77;hp=4531946c85a00a2ce8542658a459304ee2d130ba;hpb=a63cd862186adf328e26dd1294e7a3b1adc42ed6;p=scpubgit%2FObject-Remote.git

diff --git a/lib/Object/Remote/MiniLoop.pm b/lib/Object/Remote/MiniLoop.pm
index 4531946..c23bfa1 100644
--- a/lib/Object/Remote/MiniLoop.pm
+++ b/lib/Object/Remote/MiniLoop.pm
@@ -2,7 +2,7 @@ package Object::Remote::MiniLoop;
 
 use IO::Select;
 use Time::HiRes qw(time);
-use Object::Remote::Logging qw( :log );
+use Object::Remote::Logging qw( :log :dlog );
 use Moo;
 
 # this is ro because we only actually set it using local in sub run
@@ -37,12 +37,14 @@ sub pass_watches_to {
 sub watch_io {
   my ($self, %watch) = @_;
   my $fh = $watch{handle};
-  log_debug { my $type = ref($fh); "Adding watch for ref of type '$type'" };
+  Dlog_debug { my $type = ref($fh); "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} = $cb;
   }
@@ -52,12 +54,14 @@ sub watch_io {
 sub unwatch_io {
   my ($self, %watch) = @_;
   my $fh = $watch{handle};
-  log_debug { my $type = ref($fh); "Removing watch for ref of type '$type'" };
+  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};
   }
@@ -74,7 +78,7 @@ sub watch_time {
   my $timers = $self->_timers;
   my $new = [ $at => $code ];
   @{$timers} = sort { $a->[0] <=> $b->[0] } @{$timers}, $new;
-  log_debug { "Created new timer with id of '$new' that expires at '$at'" };
+  log_debug { "Created new timer that expires at '$at'" };
   return "$new";
 }
 
@@ -85,49 +89,106 @@ sub unwatch_time {
   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;
-  log_trace {  sprintf("Run loop: loop_once() has been invoked by $c[1]:$c[2] with read:%i write:%i", scalar(keys(%$read)), scalar(keys(%$write))) };
+  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 has readable:$readable_count writeable:$writable_count";
+    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 { "Run loop: run_while_wanted() invoked" };
+  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;
@@ -135,9 +196,19 @@ sub run_while_wanted {
 
 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" };