8 files changed, 25 insertions, 3 deletions
diff --git a/grc/python/Connection.py b/grc/python/Connection.py
index 218baf074..341dd2d82 100644
--- a/grc/python/Connection.py
+++ b/grc/python/Connection.py
@@ -31,6 +31,9 @@ class Connection(_Connection, _GUIConnection):
 	def is_msg(self):
 		return self.get_source().get_type() == self.get_sink().get_type() == 'msg'
 
+	def is_message(self):
+		return self.get_source().get_type() == self.get_sink().get_type() == 'message'
+
 	def validate(self):
 		"""
 		Validate the connections.
diff --git a/grc/python/Constants.py b/grc/python/Constants.py
index 1a65caf1c..b8dc9a96a 100644
--- a/grc/python/Constants.py
+++ b/grc/python/Constants.py
@@ -58,6 +58,7 @@ CORE_TYPES = ( #name, key, sizeof, color
 	('Integer 16', 's16', 2, '#FFFF66'),
 	('Integer 8', 's8', 1, '#FF66FF'),
 	('Message Queue', 'msg', 0, '#777777'),
+	('Async Message', 'message', 0, '#C0C0C0'),
 	('Wildcard', '', 0, '#FFFFFF'),
 )
 
diff --git a/grc/python/FlowGraph.py b/grc/python/FlowGraph.py
index 89a169355..efe362760 100644
--- a/grc/python/FlowGraph.py
+++ b/grc/python/FlowGraph.py
@@ -64,6 +64,7 @@ class FlowGraph(_FlowGraph, _GUIFlowGraph):
 			'type': str(pad.get_param('type').get_evaluated()),
 			'vlen': str(pad.get_param('vlen').get_evaluated()),
 			'size': pad.get_param('type').get_opt('size'),
+			'optional': bool(pad.get_param('optional').get_evaluated()),
 		} for pad in sorted_pads]
 
 	def get_pad_sources(self):
diff --git a/grc/python/Generator.py b/grc/python/Generator.py
index 2a6fe51d5..616ea00fc 100644
--- a/grc/python/Generator.py
+++ b/grc/python/Generator.py
@@ -116,8 +116,9 @@ Add a Misc->Throttle block to your flow graph to avoid CPU congestion.''')
 		#list of regular blocks (all blocks minus the special ones)
 		blocks = filter(lambda b: b not in (imports + parameters), blocks)
 		#list of connections where each endpoint is enabled
-		connections = filter(lambda c: not c.is_msg(), self._flow_graph.get_enabled_connections())
+		connections = filter(lambda c: not (c.is_msg() or c.is_message()), self._flow_graph.get_enabled_connections())
 		messages = filter(lambda c: c.is_msg(), self._flow_graph.get_enabled_connections())
+		messages2 = filter(lambda c: c.is_message(), self._flow_graph.get_enabled_connections())
 		#list of variable names
 		var_ids = [var.get_id() for var in parameters + variables]
 		#prepend self.
@@ -142,6 +143,7 @@ Add a Misc->Throttle block to your flow graph to avoid CPU congestion.''')
 			'blocks': blocks,
 			'connections': connections,
 			'messages': messages,
+			'messages2': messages2,
 			'generate_options': self._generate_options,
 			'var_id2cbs': var_id2cbs,
 		}
diff --git a/grc/python/Port.py b/grc/python/Port.py
index 9f8b50d05..738a33ba7 100644
--- a/grc/python/Port.py
+++ b/grc/python/Port.py
@@ -116,7 +116,7 @@ class Port(_Port, _GUIPort):
 		_Port.validate(self)
 		if not self.get_enabled_connections() and not self.get_optional():
 			self.add_error_message('Port is not connected.')
-		if not self.is_source() and len(self.get_enabled_connections()) > 1:
+		if not self.is_source() and (not self.get_type() == "message") and len(self.get_enabled_connections()) > 1:
 			self.add_error_message('Port has too many connections.')
 		#message port logic
 		if self.get_type() == 'msg':
diff --git a/grc/python/block.dtd b/grc/python/block.dtd
index 41a744d07..292ea06cb 100644
--- a/grc/python/block.dtd
+++ b/grc/python/block.dtd
@@ -25,7 +25,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 	Top level element.
 	A block contains a name, ...parameters list, and list of IO ports.
  -->
-<!ELEMENT block (name, key, category?, throttle?, import*, var_make?, make, callback*, param*, check*, sink*, source*, doc?)>
+<!ELEMENT block (name, key, category?, throttle?, import*, var_make?, make, callback*, param*, check*, sink*, source*, doc?, grc_source?)>
 <!--
 	Sub level elements.
  -->
@@ -40,6 +40,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 <!ELEMENT category (#PCDATA)>
 <!ELEMENT import (#PCDATA)>
 <!ELEMENT doc (#PCDATA)>
+<!ELEMENT grc_source (#PCDATA)>
 <!ELEMENT name (#PCDATA)>
 <!ELEMENT key (#PCDATA)>
 <!ELEMENT check (#PCDATA)>
diff --git a/grc/python/convert_hier.py b/grc/python/convert_hier.py
index c6ca5b769..b609af24a 100644
--- a/grc/python/convert_hier.py
+++ b/grc/python/convert_hier.py
@@ -62,6 +62,7 @@ def convert_hier(flow_graph, python_file):
 		sink_n['name'] = input_sig['label']
 		sink_n['type'] = input_sig['type']
 		sink_n['vlen'] = input_sig['vlen']
+		if input_sig['optional']: sink_n['optional'] = '1'
 		block_n['sink'].append(sink_n)
 	#source data
 	block_n['source'] = list()
@@ -70,9 +71,11 @@ def convert_hier(flow_graph, python_file):
 		source_n['name'] = output_sig['label']
 		source_n['type'] = output_sig['type']
 		source_n['vlen'] = output_sig['vlen']
+		if output_sig['optional']: source_n['optional'] = '1'
 		block_n['source'].append(source_n)
 	#doc data
 	block_n['doc'] = "%s\n%s\n%s"%(block_author, block_desc, python_file)
+	block_n['grc_source'] = "%s"%(flow_graph.grc_file_path)
 	#write the block_n to file
 	xml_file = python_file + '.xml'
 	ParseXML.to_file({'block': block_n}, xml_file)
diff --git a/grc/python/flow_graph.tmpl b/grc/python/flow_graph.tmpl
index 17feb01f6..af55ad641 100644
--- a/grc/python/flow_graph.tmpl
+++ b/grc/python/flow_graph.tmpl
@@ -189,6 +189,17 @@ gr.io_signaturev($(len($io_sigs)), $(len($io_sigs)), [$(', '.join($size_strs))])
 		self.connect($make_port_sig($source), $make_port_sig($sink))
 	#end if
 #end for
+########################################################
+##Create Asynch Message Connections
+########################################################
+#if $messages2
+		$DIVIDER
+		# Asynch Message Connections
+		$DIVIDER
+#end if
+#for $msg in $messages2
+		self.msg_connect(self.$msg.get_source().get_parent().get_id(), "$msg.get_source().get_name()", self.$msg.get_sink().get_parent().get_id(), "$msg.get_sink().get_name()")
+#end for
 
 ########################################################
 ##Create Callbacks