Fix serialization bwc broken in #511 (#515)

storey/flow.py

@@ -797,16 +797,17 @@ def __init__(self, status, body):
 
 class _ConcurrentJobExecution(Flow):
     _BACKOFF_MAX = 120
+    _DEFAULT_MAX_IN_FLIGHT = 8
 
     def __init__(self, max_in_flight=None, retries=None, backoff_factor=None, **kwargs):
         Flow.__init__(self, **kwargs)
         if max_in_flight is not None and max_in_flight < 1:
             raise ValueError(f"max_in_flight may not be less than 1 (got {max_in_flight})")
+        self.max_in_flight = max_in_flight
         self.retries = retries
         self.backoff_factor = backoff_factor
 
-        self._max_in_flight = max_in_flight or 8
-        self._queue_size = self._max_in_flight - 1
+        self._queue_size = (max_in_flight or self._DEFAULT_MAX_IN_FLIGHT) - 1
 
     def _init(self):
         super()._init()
@@ -963,9 +964,9 @@ def __init__(
 
         self._executor = None
         if concurrency_mechanism == "threading":
-            self._executor = ThreadPoolExecutor(max_workers=self._max_in_flight)
+            self._executor = ThreadPoolExecutor(max_workers=self.max_in_flight or self._DEFAULT_MAX_IN_FLIGHT)
         elif concurrency_mechanism == "multiprocessing":
-            self._executor = ProcessPoolExecutor(max_workers=self._max_in_flight)
+            self._executor = ProcessPoolExecutor(max_workers=self.max_in_flight or self._DEFAULT_MAX_IN_FLIGHT)
 
         self._pass_context = pass_context