Add config.DropECReservations

For now this function does nothing, but it gets called by mcpu when the
execution of an LU is done, making sure any pending reservations are
dropped.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

lib/config.py

@@ -1379,3 +1379,11 @@ class ConfigWriter:
         self._temporary_macs.discard(nic.mac)
 
     self._WriteConfig(feedback_fn=feedback_fn)
+
+  @locking.ssynchronized(_config_lock)
+  def DropECReservations(self, ec_id):
+    """Drop per-execution-context reservations
+
+    """
+    pass
+

lib/mcpu.py

@@ -451,8 +451,13 @@ class Processor(object):
             lu.ExpandNames()
             assert lu.needed_locks is not None, "needed_locks not set by LU"
 
-            return self._LockAndExecLU(lu, locking.LEVEL_INSTANCE,
-                                       timeout_strategy.CalcRemainingTimeout)
+            try:
+              return self._LockAndExecLU(lu, locking.LEVEL_INSTANCE,
+                                         timeout_strategy.CalcRemainingTimeout)
+            finally:
+              if self._ec_id:
+                self.context.cfg.DropECReservations(self._ec_id)
+
           finally:
             self.context.glm.release(locking.LEVEL_CLUSTER)