MultiThreadedExecutor.shutdown does not shut down underlying threadpool

  ros2/rclpy#893

Signed-off-by: Tomoya Fujita <[email protected]>

prover_rclpy/setup.py

@@ -44,6 +44,7 @@
             'rclpy_857 = src.rclpy_857:main',
             'rclpy_879 = src.rclpy_879:main',
             'rclpy_881 = src.rclpy_881:main',
+            'rclpy_893 = src.rclpy_893:main',
             'rclpy_911 = src.rclpy_911:main',
             'rclpy_912 = src.rclpy_912:main',
             'rclpy_944 = src.rclpy_944:main',

prover_rclpy/src/rclpy_893.py

@@ -0,0 +1,34 @@
+import threading
+
+import rclpy
+from rclpy.executors import MultiThreadedExecutor
+from rclpy.node import Node
+
+class TestNode(Node):
+    def __init__(self, n=10):
+        super().__init__('test_node')
+        # Create a timer to give the executor something to do
+        self.create_timer(0., callback=lambda: None)
+
+
+def main(args=None):
+    rclpy.init()
+    executor = MultiThreadedExecutor()
+    node = TestNode()
+
+
+    # Spin once to give the executor some work to do (creating threads)
+    rclpy.spin_once(node, executor=executor)
+
+    print("Shutting down")
+    rclpy.shutdown()
+    node.destroy_node()
+    # This will shutdown the ThreadpoolExecutor
+    #executor._executor.shutdown()
+    executor.shutdown()
+
+    print(f"Leftover Threads: {threading.enumerate()}")
+
+
+if __name__ == '__main__':
+    main()