asyncio generator issue

asyncio_generator_issue.py

import asyncio


async def generator_fn():
    print(f"    enter generator {id(asyncio.Task.current_task())}")

    try:
        while True:
            yield
    except:
        print(f"    except generator {id(asyncio.Task.current_task())}")
        raise
    finally:
        print(f"    finally generator {id(asyncio.Task.current_task())}")


async def caller():
    print(f"  enter caller {id(asyncio.Task.current_task())}")

    try:
        async for _ in generator_fn():
            break
    finally:
        print(f"  finally caller {id(asyncio.Task.current_task())}")


async def main():
    print(f"enter main {id(asyncio.Task.current_task())}")
    try:
        await asyncio.ensure_future(caller())
    finally:
        print(f"exit main {id(asyncio.Task.current_task())}")

asyncio.get_event_loop().run_until_complete(main())

This generates output like the following:

  enter caller 4484635776
    enter generator 4484635776
  finally caller 4484635776
    except generator 4484635912
    finally generator 4484635912
exit main 4484635640

notice how the generator except/finally don't have the same task as when it was entered, and further that it's a completely different task that I did not create.