tasks can now terminate faster when no items were read, without neglecting their duty to close the channel if required. Code is a little less maintainable now, but faster, it appears

Author: Byron

lib/git/async/task.py

@@ -92,21 +92,24 @@ def process(self, count=0):
 		#	print "from", self.reader().channel
 		items = self._read(count)
 		#print "%r: done reading %i items" % (self.id, len(items))
+		
 		try:
 			try:
-				write = self._out_writer.write
-				if self.apply_single:
-					for item in items:
-						rval = self.fun(item)
-						write(rval)
-					# END for each item
-				else:
-					# shouldn't apply single be the default anyway ? 
-					# The task designers should chunk them up in advance
-					rvals = self.fun(items)
-					for rval in rvals:
-						write(rval)
-				# END handle single apply
+				if items:
+					write = self._out_writer.write
+					if self.apply_single:
+						for item in items:
+							rval = self.fun(item)
+							write(rval)
+						# END for each item
+					else:
+						# shouldn't apply single be the default anyway ? 
+						# The task designers should chunk them up in advance
+						rvals = self.fun(items)
+						for rval in rvals:
+							write(rval)
+					# END handle single apply
+				# END if there is anything to do
 			finally:
 				self._wlock.acquire()
 				self._num_writers -= 1
@@ -158,12 +161,14 @@ def process(self, count=0):
 		# Soft close, so others can continue writing their results
 		if self.is_done():
 			self._wlock.acquire()
-			if self._num_writers == 0:
-				#if not self.is_closed():		# DEBUG 
-				#	print "Closing channel of %r" % self.id, len(self._out_writer.channel.queue), self._out_writer.channel
-				self.close()
-			# END handle writers
-			self._wlock.release()
+			try:
+				if self._num_writers == 0:
+					# print "Closing channel of %r" % self.id, len(self._out_writer.channel.queue), self._out_writer.channel
+					self.close()
+				# END handle writers
+			finally:
+				self._wlock.release()
+			# END assure lock release
 		# END handle channel closure
 	#{ Configuration