Address review comments

launch_ros/launch_ros/default_launch_description.py

@@ -96,7 +96,9 @@ def _run(self):
 
     def _function(self, context: launch.LaunchContext):
         try:
-            rclpy.init(args=context.argv, context=self.__rclpy_context)
+            if self.__rclpy_context is None:
+                # Initialize the default global context
+                rclpy.init(args=context.argv)
         except RuntimeError as exc:
             if 'rcl_init called while already initialized' in str(exc):
                 pass
@@ -121,8 +123,9 @@ def get_default_launch_description(*, prefix_output_with_name=False, rclpy_conte
         with the name of the process as `[process_name] `, else it is printed
         unmodified
 
-    :param: rclpy_context Provide a context other than the default rclpy context pass down
-    to rclpy.init
+    :param: rclpy_context Provide a context other than the default rclpy context to pass down
+    to rclpy.init.  The context is expected to have already been initialized by the caller using
+    rclpy.init
     """
     default_ros_launch_description = launch.LaunchDescription([
         # ROS initialization (create node and other stuff).

ros2launch/ros2launch/api/api.py

@@ -27,6 +27,8 @@
 from launch.launch_description_sources import InvalidPythonLaunchFileError
 from launch.launch_description_sources import load_python_launch_file_as_module
 import launch_ros
+import rclpy
+import rclpy.context
 
 # forward functions into this module's default namespace (useful for some autocompletion tools)
 get_launch_description_from_python_launch_file = get_launch_description_from_python_launch_file
@@ -137,8 +139,14 @@ def parse_launch_arguments(launch_arguments: List[Text]) -> List[Tuple[Text, Tex
 def launch_a_python_launch_file(*, python_launch_file_path, launch_file_arguments, debug=False):
     """Launch a given Python launch file (by path) and pass it the given launch file arguments."""
     launch_service = launch.LaunchService(argv=launch_file_arguments, debug=debug)
+    context = rclpy.context.Context()
+    rclpy.init(args=launch_file_arguments, context=context)
     launch_service.include_launch_description(
-        launch_ros.get_default_launch_description(prefix_output_with_name=False))
+        launch_ros.get_default_launch_description(
+            prefix_output_with_name=False,
+            rclpy_context=context,
+        )
+    )
     parsed_launch_arguments = parse_launch_arguments(launch_file_arguments)
     # Include the user provided launch file using IncludeLaunchDescription so that the
     # location of the current launch file is set.
@@ -151,7 +159,9 @@ def launch_a_python_launch_file(*, python_launch_file_path, launch_file_argument
         ),
     ])
     launch_service.include_launch_description(launch_description)
-    return launch_service.run()
+    ret = launch_service.run()
+    context = rclpy.shutdown(context=context)
+    return ret
 
 
 class LaunchFileNameCompleter: