fix call for Python versions

Signed-off-by: Sylvain Hellegouarch <[email protected]>

Author: Lawouach

CHANGELOG.md

@@ -2,7 +2,15 @@
 
 ## [Unreleased][]
 
-[Unreleased]: https://github.com/chaostoolkit/chaostoolkit-addons/compare/0.8.3...HEAD
+[Unreleased]: https://github.com/chaostoolkit/chaostoolkit-addons/compare/0.8.4...HEAD
+
+## [0.8.4][]
+
+[0.8.4]: https://github.com/chaostoolkit/chaostoolkit-addons/compare/0.8.3...0.8.4
+
+### Changed
+
+- `cancel_futures` is only support in Python 3.9+
 
 ## [0.8.3][]
 

chaosaddons/controls/safeguards.py

@@ -82,6 +82,7 @@
 from concurrent.futures import Future, ThreadPoolExecutor
 from datetime import datetime
 from functools import partial
+import sys
 import threading
 import time
 import traceback
@@ -240,9 +241,16 @@ def terminate(self) -> None:
 
         self.wait_for_interruption.set()
         self.repeating_until.set()
-        self.now.shutdown(wait=False, cancel_futures=False)
-        self.repeating.shutdown(wait=False, cancel_futures=False)
-        self.once.shutdown(wait=False, cancel_futures=False)
+
+        if sys.version_info >= (3, 9):
+            self.now.shutdown(wait=True, cancel_futures=True)
+            self.repeating.shutdown(wait=True, cancel_futures=True)
+            self.once.shutdown(wait=True, cancel_futures=True)
+        else:
+            self.now.shutdown(wait=True)
+            self.repeating.shutdown(wait=True)
+            self.once.shutdown(wait=True)
+
         logger.debug("Guardian is now terminated")