xenapi_conn was not terminating utils/LoopingCall when an exception was occurring. This was causing the eventlet Event to have send_exception() called more than once (a no-no).

This would have affected more than just pause/unpause, but any XenApi call that raised an exception.

2 files changed, 36 insertions, 4 deletions

diff --git a/nova/tests/xenapi/stubs.py b/nova/tests/xenapi/stubs.py
index 55f751f11..292bd9ba9 100644
--- a/nova/tests/xenapi/stubs.py
+++ b/nova/tests/xenapi/stubs.py
@@ -41,9 +41,33 @@ def stubout_instance_snapshot(stubs):
             rv = done.wait()
             return rv
 
+        def fake_loop(self):
+            pass
+
         stubs.Set(xenapi_conn.XenAPISession, 'wait_for_task',
                   fake_wait_for_task)
 
+        stubs.Set(xenapi_conn.XenAPISession, '_stop_loop', fake_loop)
+
+        from nova.virt.xenapi.fake import create_vdi
+        name_label = "instance-%s" % instance_id
+        #TODO: create fake SR record
+        sr_ref = "fakesr"
+        vdi_ref = create_vdi(name_label=name_label, read_only=False,
+                             sr_ref=sr_ref, sharable=False)
+        vdi_rec = session.get_xenapi().VDI.get_record(vdi_ref)
+        vdi_uuid = vdi_rec['uuid']
+        return vdi_uuid
+
+    stubs.Set(vm_utils.VMHelper, 'fetch_image', fake_fetch_image)
+
+    def fake_parse_xmlrpc_value(val):
+        return val
+
+    stubs.Set(xenapi_conn, '_parse_xmlrpc_value', fake_parse_xmlrpc_value)
+
+    def fake_wait_for_vhd_coalesce(session, instance_id, sr_ref, vdi_ref,
+                              original_parent_uuid):
         from nova.virt.xenapi.fake import create_vdi
         name_label = "instance-%s" % instance_id
         #TODO: create fake SR record
diff --git a/nova/virt/xenapi_conn.py b/nova/virt/xenapi_conn.py
index 3aaaf09ed..b8ab9245f 100644
--- a/nova/virt/xenapi_conn.py
+++ b/nova/virt/xenapi_conn.py
@@ -198,6 +198,7 @@ class XenAPISession(object):
         self.XenAPI = self.get_imported_xenapi()
         self._session = self._create_session(url)
         self._session.login_with_password(user, pw)
+        self.loop = None
 
     def get_imported_xenapi(self):
         """Stubout point. This can be replaced with a mock xenapi module."""
@@ -234,14 +235,20 @@ class XenAPISession(object):
 
     def wait_for_task(self, id, task):
         """Return the result of the given task. The task is polled
-        until it completes."""
+        until it completes. Not re-entrant."""
         done = event.Event()
-        loop = utils.LoopingCall(self._poll_task, id, task, done)
-        loop.start(FLAGS.xenapi_task_poll_interval, now=True)
+        self.loop = utils.LoopingCall(self._poll_task, id, task, done)
+        self.loop.start(FLAGS.xenapi_task_poll_interval, now=True)
         rv = done.wait()
-        loop.stop()
+        self.loop.stop()
         return rv
 
+    def _stop_loop(self):
+        """Stop polling for task to finish."""
+        #NOTE(sandy-walsh) Had to break this call out to support unit tests.
+        if self.loop:
+            self.loop.stop()
+
     def _create_session(self, url):
         """Stubout point. This can be replaced with a mock session."""
         return self.XenAPI.Session(url)
@@ -278,6 +285,7 @@ class XenAPISession(object):
         except self.XenAPI.Failure, exc:
             LOG.warn(exc)
             done.send_exception(*sys.exc_info())
+        self._stop_loop()
 
     def _unwrap_plugin_exceptions(self, func, *args, **kwargs):
         """Parse exception details"""