Fix event handling for our own libvirt event loop.

Was ignoring event 0 which is used to stop "polling" events.
Was using mapping which couldn't work with multiple events.

ccnode/hypervisor/lib.py

@@ -54,27 +54,40 @@ class LoopHandler(object):
 
     """
     def __init__(self, loop, handle, fd, events, cb, opaque):
-        # events conversion
-        self.events_map = {
-            pyev.EV_READ: libvirt.VIR_EVENT_HANDLE_READABLE,
-            pyev.EV_WRITE: libvirt.VIR_EVENT_HANDLE_WRITABLE,
-        }
-        self.revents_map = {
-            libvirt.VIR_EVENT_HANDLE_READABLE: pyev.EV_READ,
-            libvirt.VIR_EVENT_HANDLE_WRITABLE: pyev.EV_WRITE,
-        }
-
         self.handle = handle
         self.fd = fd
-        self._events = self.revents_map[events]
+        self._events = self.virt_to_ev(events)
         self._cb = cb
         self.opaque = opaque
         self.watcher = loop.io(self.fd, self._events, self.ev_cb)
 
+    def ev_to_virt(self, events):
+        """Convert libev events into libvirt one."""
+        result = 0
+        if events & pyev.EV_READ:
+            result |= libvirt.VIR_EVENT_HANDLE_READABLE
+        if events & pyev.EV_WRITE:
+            result |= libvirt.VIR_EVENT_HANDLE_WRITABLE
+
+        return result
+
+    def virt_to_ev(self, events):
+        """Convert libvirt event to libev one."""
+        result = 0
+        if events & (libvirt.VIR_EVENT_HANDLE_READABLE |
+                     libvirt.VIR_EVENT_HANDLE_ERROR |
+                     libvirt.VIR_EVENT_HANDLE_HANGUP):
+            result |= pyev.EV_READ
+        if events & libvirt.VIR_EVENT_HANDLE_WRITABLE:
+            result |= pyev.EV_WRITE
+
+        return result
+
     def _set(self):
         self.watcher.stop()
-        self.watcher.set(self.fd, self._events)
-        self.watcher.start()
+        if self._events != 0:
+            self.watcher.set(self.fd, self._events)
+            self.watcher.start()
 
     @property
     def events(self):
@@ -82,7 +95,7 @@ class LoopHandler(object):
 
     @events.setter
     def events(self, events):
-        self._events = self.revents_map[events]
+        self._events = self.virt_to_ev(events)
         self._set()
 
     def start(self):
@@ -93,7 +106,7 @@ class LoopHandler(object):
 
     def ev_cb(self, watcher, revents):
         # convert events
-        events = self.events_map[revents]
+        events = self.ev_to_virt(revents)
         self._cb(self.handle, self.watcher.fd, events, self.opaque[0],
                  self.opaque[1])