[trac533] proposed fix for trac #533: fixing parameters for kqueue APIs.

Also made it more portable not to use select.KQ_* until the add/delete
methods are actually called.

src/bin/msgq/msgq.py.in

@@ -136,14 +136,29 @@ class MsgQ:
         except AttributeError:
             self.kqueue = select.kqueue()
     
-    def add_kqueue_socket(self, socket, enable_write = False):
-        filters = select.KQ_FILTER_READ
-        if enable_write:
-            filters |= select.KQ_FILTER_WRITE
-        event = select.kevent(socket.fileno(), filters,
+    def add_kqueue_socket(self, socket, write_filter=False):
+        """Add a kquque filter for a socket.  By default the read
+        filter is used; if write_filter is set to True, the write
+        filter is used.  We use a boolean value instead of a specific
+        filter constant, because kqueue filter values do not seem to
+        be defined on some systems.  The use of boolean makes the
+        interface restrictive because there are other filters, but this
+        method is mostly only for our internal use, so it should be
+        acceptable at least for now."""
+        filter_type = select.KQ_FILTER_WRITE if write_filter else \
+            select.KQ_FILTER_READ
+        event = select.kevent(socket.fileno(), filter_type,
                               select.KQ_EV_ADD | select.KQ_EV_ENABLE)
         self.kqueue.control([event], 0)
 
+    def delete_kqueue_socket(self, socket, write_filter=False):
+        """Delete a kqueue filter for socket.  See add_kqueue_socket()
+        for the semantics and notes about write_filter."""
+        filter_type = select.KQ_FILTER_WRITE if write_filter else \
+            select.KQ_FILTER_READ
+        event = select.kevent(socket.fileno(), filter_type,
+                              select.KQ_EV_DELETE)
+        self.kqueue.control([event], 0)
 
     def setup_listener(self):
         """Set up the listener socket.  Internal function."""
@@ -376,7 +391,7 @@ class MsgQ:
             if self.poller:
                 self.poller.register(fileno, select.POLLIN)
             else:
-                self.add_kqueue_socket(sock)
+                self.delete_kqueue_socket(sock, True)
             del self.sendbuffs[fileno]
         else:
             self.sendbuffs[fileno] = (time.clock(), msg)
@@ -468,12 +483,14 @@ class MsgQ:
                 if event.ident == self.listen_socket.fileno():
                     self.process_accept()
                 else:
-                    if event.flags & select.KQ_FILTER_WRITE:
-                        self.process_socket(event.ident)
-                    if event.flags & select.KQ_FILTER_READ and event.data > 0:
+                    if event.filter == select.KQ_FILTER_WRITE:
+                        self.__process_write(event.ident)
+                    if event.filter == select.KQ_FILTER_READ and \
+                            event.data > 0:
                         self.process_socket(event.ident)
                     elif event.flags & select.KQ_EV_EOF:
-                        self.kill_socket(event.ident, self.sockets[event.ident])
+                        self.kill_socket(event.ident,
+                                         self.sockets[event.ident])
 
     def shutdown(self):
         """Stop the MsgQ master."""