Launcher hangs with keyboard interrupt on Windows about launch

[dhood]

Clarification: this is referring to python scripts that create their own launcher manually and are invoked with python directly.

As @wjwwood noted in ros2/demos#175 (comment) this does NOT happen for "launch files" that are invoked with launch, e.g. https://github.com/ros2/demos/blob/a4d48aa57ba5752122c23bf79e0959052b96337e/lifecycle/launch/lifecycle_demo_launch.py

[dhood]

I'm at a loss as to why converting the example into the same format as https://github.com/ros2/demos/blob/a4d48aa57ba5752122c23bf79e0959052b96337e/lifecycle/launch/lifecycle_demo_launch.py doesn't fix it.

This still hangs (executed with launch rather than python) on Windows:

import os

from launch.exit_handler import primary_exit_handler

def launch(launch_descriptor, argv):
    
    if os.name == 'nt':
        cmd=['ping', '127.0.0.1', '-n', '60']
    else:
        cmd=['sleep', '60']
    launch_descriptor.add_process(
        cmd=cmd,
    )
    launch_descriptor.add_process(
        cmd=cmd,
        exit_handler=primary_exit_handler,
    )

I have on one occasion seen it exit cleanly so there might be a race condition involved.

[rhololkeolke]

I have this same issue on Linux. It seems that loop.run_forever is called, but loop.stop is never called.

If you add a loop.stop to the end of DefaultLaunch._run it fixes the issue. However, I'm not sure if it causes any other issues. I'm not super familiar with the asyncio library.

[sloretz]

FYI for future readers, #69 fixed on OSX, but issue still exists on windows.

[wjwwood]

Closing since the legacy launch testing is no longer in use.