Use a AND instead of an OR to determine if the bits are set on the event

mask.  Also, handle some basic error cases in the event bits and twisted
callback.

tornado/platform/twisted.py

@@ -32,6 +32,8 @@
 from twisted.internet.posixbase import PosixReactorBase
 from twisted.internet.interfaces import \
     IReactorFDSet, IDelayedCall, IReactorTime
+from twisted.python import failure
+from twisted.internet import error
 
 from zope.interface import implements
 
@@ -40,6 +42,7 @@
 from tornado.stack_context import NullContext
 from tornado.ioloop import IOLoop
 
+
 class TornadoDelayedCall(object):
     """
     DelayedCall object for Tornado.
@@ -139,10 +142,15 @@ def wakeUp(self):
     # IReactorFDSet
     def _invoke_callback(self, fd, events):
         (reader, writer) = self._fds[fd]
-        if events | IOLoop.READ and reader:
+        if events & IOLoop.READ and reader:
             reader.doRead()
-        if events | IOLoop.WRITE and writer:
+        if events & IOLoop.WRITE and writer:
             writer.doWrite()
+	if events & IOLoop.ERROR:
+	    if reader:
+	        reader.readConnectionLost(failure.Failure(error.ConnectionLost()))
+	    if writer:
+	        writer.connectionLost(failure.Failure(error.ConnectionLost()))
 
     def addReader(self, reader):
         """