BFD: fix timing in the main loop

Properly wakeup the main process loop only when necessary to avoid
missed events. Improve BFD unit test reliability and speed. Add
timestamps to logs and replace Queue with more efficient deque.

Change-Id: I01255a02057d3146917b43b669ccdc74f31ef0c8
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 17 insertions, 11 deletions

diff --git a/test/vpp_papi_provider.py b/test/vpp_papi_provider.py
index 5e80a03e..c45518bd 100644
--- a/test/vpp_papi_provider.py
+++ b/test/vpp_papi_provider.py
@@ -2,6 +2,7 @@ import os
 import fnmatch
 import time
 from hook import Hook
+from collections import deque
 
 # Sphinx creates auto-generated documentation by importing the python source
 # files and collecting the docstrings from them. The NO_VPP_PAPI flag allows the
@@ -48,7 +49,7 @@ class VppPapiProvider(object):
                 jsonfiles.append(os.path.join(root, filename))
 
         self.papi = VPP(jsonfiles)
-        self._events = list()
+        self._events = deque()
 
     def register_hook(self, hook):
         """Replace hook registration with new hook
@@ -59,19 +60,25 @@ class VppPapiProvider(object):
         self.hook = hook
 
     def collect_events(self):
+        """ Collect all events from the internal queue and clear the queue. """
         e = self._events
-        self._events = list()
+        self._events = deque()
         return e
 
     def wait_for_event(self, timeout, name=None):
+        """ Wait for and return next event. """
+        if self._events:
+            self.test_class.logger.debug("Not waiting, event already queued")
         limit = time.time() + timeout
         while time.time() < limit:
             if self._events:
-                e = self._events.pop(0)
+                e = self._events.popleft()
                 if name and type(e).__name__ != name:
                     raise Exception(
                         "Unexpected event received: %s, expected: %s" %
                         (type(e).__name__, name))
+                self.test_class.logger.debug("Returning event %s:%s" %
+                                             (name, e))
                 return e
             time.sleep(0)  # yield
         if name is not None:
@@ -79,8 +86,10 @@ class VppPapiProvider(object):
         raise Exception("Event did not occur within timeout")
 
     def __call__(self, name, event):
+        """ Enqueue event in the internal event queue. """
         # FIXME use the name instead of relying on type(e).__name__ ?
         # FIXME #2 if this throws, it is eaten silently, Ole?
+        self.test_class.logger.debug("New event: %s: %s" % (name, event))
         self._events.append(event)
 
     def connect(self):
@@ -93,7 +102,7 @@ class VppPapiProvider(object):
         self.papi.disconnect()
 
     def api(self, api_fn, api_args, expected_retval=0):
-        """Call API function and check it's return value
+        """ Call API function and check it's return value.
         Call the appropriate hooks before and after the API call
 
         :param api_fn: API function to call
@@ -107,14 +116,13 @@ class VppPapiProvider(object):
         if hasattr(reply, 'retval') and reply.retval != expected_retval:
             msg = "API call failed, expected retval == %d, got %s" % (
                 expected_retval, repr(reply))
-            self.test_class.logger.error(msg)
+            self.test_class.logger.info(msg)
             raise Exception(msg)
         self.hook.after_api(api_fn.__name__, api_args)
         return reply
 
     def cli(self, cli):
-        """
-        Execute a CLI, calling the before/after hooks appropriately.
+        """ Execute a CLI, calling the before/after hooks appropriately.
 
         :param cli: CLI to execute
         :returns: CLI output
@@ -128,8 +136,7 @@ class VppPapiProvider(object):
             return r.reply.decode().rstrip('\x00')
 
     def ppcli(self, cli):
-        """
-        Helping method to print CLI command in case of info logging level.
+        """ Helper method to print CLI command in case of info logging level.
 
         :param cli: CLI to execute
         :returns: CLI output
@@ -165,8 +172,7 @@ class VppPapiProvider(object):
         return self.api(self.papi.sw_interface_dump, args)
 
     def sw_interface_set_table(self, sw_if_index, is_ipv6, table_id):
-        """
-          Set the IPvX Table-id for the Interface
+        """ Set the IPvX Table-id for the Interface
 
         :param sw_if_index:
         :param is_ipv6: