Re: Making QEMU easier for management tools and applications

[John Snow]

On 1/25/20 6:41 AM, Paolo Bonzini wrote:
> On 20/01/20 10:55, Stefan Hajnoczi wrote:
>>>
>>> [1] https://qemu.readthedocs.io/en/latest/interop/live-block-operations.html
>> John and I discussed async events in the past.  qmp-shell currently uses
>> the input() built-in function.  If we modify it with a
>> select(2)/poll(2)-style function that monitors both stdin and the QMP
>> socket then it could print QMP events as soon as they are received.
> 
> I think it should be rewritten using async/await.  A simple example:
> 
>     import asyncio
>     import sys
>     from concurrent.futures import ThreadPoolExecutor
> 
>     async def ainput(prompt: str = ""):
>         with ThreadPoolExecutor(1, "ainput") as executor:
>             return (await asyncio.get_event_loop().run_in_executor(
>                 executor, sys.stdin.readline
>             )).rstrip()
> 
>     async def numbers():
>         i = 1
>         while True:
>             print(i)
>             i = i + 1
>             await asyncio.sleep(1)
> 
>     async def main():
>         name = await ainput("What's your name? ")
>         print("Hello, {}!".format(name))
> 
>     asyncio.get_event_loop().create_task(numbers())
>     asyncio.get_event_loop().run_until_complete(main())
> 
> This would be a great Summer of Code project.  Even an autocompletion
> interface using readline should be possible.
> 
> Paolo
> 

I wrote an async version at one point; I had problems integrating
asyncio with readline functionality.

--js