Merge pull request #590 from dpkp/accumulator_bugfix

Fix producer threading bug that can crash sender

kafka/producer/record_accumulator.py

@@ -248,11 +248,12 @@ class RecordAccumulator(object):
         expired_batches = []
         to_remove = []
         count = 0
-        for tp, dq in six.iteritems(self._batches):
+        for tp in list(self._batches.keys()):
             assert tp in self._tp_locks, 'TopicPartition not in locks dict'
             with self._tp_locks[tp]:
                 # iterate over the batches and expire them if they have stayed
                 # in accumulator for more than request_timeout_ms
+                dq = self._batches[tp]
                 for batch in dq:
                     # check if the batch is expired
                     if batch.maybe_expire(request_timeout_ms,
@@ -367,8 +368,9 @@ class RecordAccumulator(object):
 
     def has_unsent(self):
         """Return whether there is any unsent record in the accumulator."""
-        for tp, dq in six.iteritems(self._batches):
+        for tp in list(self._batches.keys()):
             with self._tp_locks[tp]:
+                dq = self._batches[tp]
                 if len(dq):
                     return True
         return False