PERFORCE change 121848 for review

[Andrew Turner]

http://perforce.freebsd.org/chv.cgi?CH=121848

Change 121848 by andrew at andrew_hermies on 2007/06/17 11:45:03

	Create a thread to communicate with the back end
	Add a lock to syncronise the closing of the connection
	Send a ping to the back end to test interaction
	Stop reading data when the back end sends a </facund-server>
	
	The back and front ends can now communicate with each other. Currently they just send ping/pong messages untill the connection is closed though.

Affected files ...

.. //depot/projects/soc2007/andrew-update/frontend/facund/computer.py#2 edit
.. //depot/projects/soc2007/andrew-update/frontend/facund/network/__init__.py#5 edit

Differences ...

==== //depot/projects/soc2007/andrew-update/frontend/facund/computer.py#2 (text+ko) ====

@@ -26,10 +26,12 @@
 
 import socket
 import facund.network
+import threading
 
-class Computer:
+class Computer(threading.Thread):
 	'''A class to describe each computer able to be connected to'''
 	def __init__(self, name, host):
+		threading.Thread.__init__(self)
 		self.__name = name
 		self.__host = host
 		self.__dirs = []
@@ -67,6 +69,9 @@
 		try:
 			self.__connection = \
 			    facund.network.Connection(self.__host)
+
+			# Start the communication thread
+			self.start()
 		except socket.error:
 			print "Couldn't connect to " + self.__host
 			self.__connection = None
@@ -79,3 +84,7 @@
 		self.__connection.disconnect()
 		self.__connection = None
 
+	def run(self):
+		'''The main communications thread'''
+		while self.__connection.interact():
+			continue

==== //depot/projects/soc2007/andrew-update/frontend/facund/network/__init__.py#5 (text+ko) ====

@@ -24,8 +24,9 @@
 # SUCH DAMAGE.
 #
 
+import socket
+import threading
 import xml.sax.handler
-import socket
 
 class Connection(xml.sax.handler.ContentHandler):
 	'''A class that works as a client with the Facund XML IPC'''
@@ -39,33 +40,47 @@
 		self.parser = xml.sax.make_parser()
 		self.parser.setContentHandler(self)
 
+		self.__connected_lock = threading.Lock()
+
 		self.canClose = False
 		# Mark the class as ready and able to disconnect
 		self.isReady = True
 
+		self.socket.send("<call name=\"ping\" id=\"1\"/>")
+
 	def disconnect(self):
 		if self.isReady:
 			self.isReady = False
 			# Send a connection close
 			self.socket.send("</facund-client>")
 
-			# Wait for the server to close the connection
-			while not self.canClose:
-				self.interact()
+			# Wait for the other end to close
+			self.__connected_lock.acquire()
+			self.__connected_lock.release()
+
 			self.parser.close()
 
 	def interact(self):
 		'''Reads data from the connection and passes it to the
 		XML parser'''
-		data = self.socket.recv(self.bufSize)
-		self.parser.feed(data)
+		if not self.canClose:
+			data = self.socket.recv(self.bufSize)
+			self.parser.feed(data)
+			return True
+		return False
+	
+	def startElement(self, name, attributes):
+		print "> " + name + " " + str(attributes.items())
+		if self.isReady and name == "pong":
+			self.socket.send("<call name=\"ping\" id=\"1\"/>")
 
-	def startElement(self, name, attributes):
-		print "> " + name
+		if name == "facund-server":
+			self.__connected_lock.acquire()
 
 	def endElement(self, name):
 		print "< " + name
 		# The server send a close message
 		if name == "facund-server":
+			self.__connected_lock.release()
 			self.canClose = True