Re: Making QEMU easier for management tools and applications

[Paolo Bonzini]

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