chore: fix race condition in task A

Author: karenc-bq

aws_advanced_python_wrapper/writer_failover_handler.py

@@ -120,9 +120,9 @@ def get_result_from_future(self, current_topology: Tuple[HostInfo, ...]) -> Writ
 
             executor = ThreadPoolExecutor(thread_name_prefix="WriterFailoverHandlerExecutor")
             try:
+                futures = [executor.submit(self.reconnect_to_writer, writer_host),
+                           executor.submit(self.wait_for_new_writer, current_topology, writer_host)]
                 try:
-                    futures = [executor.submit(self.reconnect_to_writer, writer_host),
-                               executor.submit(self.wait_for_new_writer, current_topology, writer_host)]
                     for future in as_completed(futures, timeout=self._max_failover_timeout_sec):
                         logger.info("future completed")
                         result = future.result()
@@ -133,12 +133,12 @@ def get_result_from_future(self, current_topology: Tuple[HostInfo, ...]) -> Writ
                             return result
                 except TimeoutError:
                     logger.info("futures timed out")
-                    logger.info("setting timeout_event 1")
-                    self._timeout_event.set()
-                finally:
-                    logger.info("setting timeout_event 2")
                     self._timeout_event.set()
+                    # Cancel remaining futures to prevent hanging
+                    for future in futures:
+                        future.cancel()
             finally:
+                self._timeout_event.set()
                 executor.shutdown(wait=False)
 
         return WriterFailoverHandlerImpl.failed_writer_failover_result