X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FObject%2FRemote%2FMiniLoop.pm;h=60b7c27e98427fd60a98f91efbf3667b430b19ef;hb=b51a8453354ea19e42ea2a09234b1c9d1eb8ca67;hp=16216dee01587241f811e508078929358e8bd032;hpb=0511910e3a6ebd6b75d533d48d22f5fe8112b5a3;p=scpubgit%2FObject-Remote.git

diff --git a/lib/Object/Remote/MiniLoop.pm b/lib/Object/Remote/MiniLoop.pm
index 16216de..60b7c27 100644
--- a/lib/Object/Remote/MiniLoop.pm
+++ b/lib/Object/Remote/MiniLoop.pm
@@ -37,14 +37,28 @@ 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 { "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 on_read_ready has been invoked" };
+    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 on_write_ready has been invoked" };
+    log_trace { "IO watcher is registering with select for writing" };
     $self->_write_select->add($fh);
     $self->_write_watches->{$fh} = $cb;
   }
@@ -54,12 +68,14 @@ sub watch_io {
 sub unwatch_io {
   my ($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};
   }
@@ -90,10 +106,11 @@ sub unwatch_time {
 sub _next_timer_expires_delay {
   my ($self) = @_;
   my $timers = $self->_timers;
-  #undef means no timeout, only returns
+  #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;
@@ -103,12 +120,10 @@ sub _next_timer_expires_delay {
   
   if ($duration < 0) {
     $duration = 0; 
-  } elsif (! defined($delay_max)) {
-    $duration = undef; 
-  } elsif ($duration > $delay_max) {
-    $duration = $delay_max; 
+  } elsif (defined $delay_max && $duration > $delay_max) {
+    $duration = $delay_max;
   }
-    
+  
   return $duration; 
 }
 
@@ -116,16 +131,32 @@ 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 @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",
+  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_debug { 
+  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";
@@ -133,20 +164,24 @@ sub loop_once {
   # 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}();
-#    $read->{$fh}() if $read->{$fh};
+    last if $Loop_Entered;
   }
   log_trace { "Writing to all ready filehandles" };
   foreach my $fh (@$writeable) {
     next unless $write->{$fh};
     $write_count++;
     $write->{$fh}();
-#    $write->{$fh}() if $write->{$fh};
+    last if $Loop_Entered;
   }
+  
   log_trace { "Read from $read_count filehandles; wrote to $write_count filehandles" };
   my $timers = $self->_timers;
   my $now = time();
@@ -154,11 +189,15 @@ sub loop_once {
   while (@$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_debug { "Run loop: single loop is completed" };
+  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 $_" }
@@ -167,7 +206,7 @@ sub want_run {
 
 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 $self->{want_running};
   log_debug { "Run loop: run_while_wanted() completed" };
   return;
@@ -183,14 +222,20 @@ sub want_stop {
     --$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_info { "Run loop: run() invoked" };
+  log_trace { "Run loop: run() invoked" };
   local $self->{is_running} = 1;
   while ($self->is_running) {
     $self->loop_once;
   }
-  log_info { "Run loop: run() completed" };
+  log_trace { "Run loop: run() completed" };
   return;
 }