Fix ioloop._KQueue to work correctly when listening for both read and write.

kqueue.control must be called separately for each type of filter, not just
once with the filters or'd together.

Fixes http://github.com/facebook/tornado/issues/issue/59/
Change adapted from
http://github.com/weaver/tornado/commit/97e528cf6b92bbb590579864962e2d51c22202e0

diff --git a/tornado/ioloop.py b/tornado/ioloop.py
index 35d90cd1c8affc34084fe94d9819f950ddde41a4..44cdffdeaaa70ff9896517b5e4d19e17220c14b9 100644 (file)
--- a/tornado/ioloop.py
+++ b/tornado/ioloop.py
@@ -339,41 +339,47 @@ class _KQueue(object):
     """A kqueue-based event loop for BSD/Mac systems."""
     def __init__(self):
         self._kqueue = select.kqueue()
-        self._filters = {}
+        self._active = {}
 
     def register(self, fd, events):
-        filter = 0
-        if events & IOLoop.WRITE:
-            filter |= select.KQ_FILTER_WRITE
-        if events & IOLoop.READ or filter == 0:
-            filter |= select.KQ_FILTER_READ
-        self._filters[fd] = filter
-        kevent = select.kevent(fd, filter=filter)
-        self._kqueue.control([kevent], 0)
+        self._control(fd, events, select.KQ_EV_ADD)
+        self._active[fd] = events
 
     def modify(self, fd, events):
         self.unregister(fd)
         self.register(fd, events)
 
     def unregister(self, fd):
-        kevent = select.kevent(fd, filter=self._filters[fd],
-                               flags=select.KQ_EV_DELETE)
-        self._kqueue.control([kevent], 0)
+        events = self._active.pop(fd)
+        self._control(fd, events, select.KQ_EV_DELETE)
+
+    def _control(self, fd, events, flags):
+        kevents = []
+        if events & IOLoop.WRITE:
+            kevents.append(select.kevent(
+                    fd, filter=select.KQ_FILTER_WRITE, flags=flags))
+        if events & IOLoop.READ or not kevents:
+            # Always read when there is not a write
+            kevents.append(select.kevent(
+                    fd, filter=select.KQ_FILTER_READ, flags=flags))
+        # Even though control() takes a list, it seems to return EINVAL
+        # on Mac OS X (10.6) when there is more than one event in the list.
+        for kevent in kevents:
+            self._kqueue.control([kevent], 0)
 
     def poll(self, timeout):
         kevents = self._kqueue.control(None, 1000, timeout)
-        events = []
+        events = {}
         for kevent in kevents:
             fd = kevent.ident
             flags = 0
-            if kevent.filter & select.KQ_FILTER_READ:
-                flags |= IOLoop.READ
-            if kevent.filter & select.KQ_FILTER_WRITE:
-                flags |= IOLoop.WRITE
+            if kevent.filter == select.KQ_FILTER_READ:
+                events[fd] = events.get(fd, 0) | IOLoop.READ
+            if kevent.filter == select.KQ_FILTER_WRITE:
+                events[fd] = events.get(fd, 0) | IOLoop.WRITE
             if kevent.flags & select.KQ_EV_ERROR:
-                flags |= IOLoop.ERROR
-            events.append((fd, flags))
-        return events
+                events[fd] = events.get(fd, 0) | IOLoop.ERROR
+        return events.items()
 
 
 class _Select(object):