Re: [PATCH v4 4/4] python/aqmp: add socket bind step to legacy.py

[Kevin Wolf]

Am 01.02.2022 um 05:11 hat John Snow geschrieben:
> The synchronous QMP library would bind to the server address during
> __init__(). The new library delays this to the accept() call, because
> binding occurs inside of the call to start_[unix_]server(), which is an
> async method -- so it cannot happen during __init__ anymore.
> 
> Python 3.7+ adds the ability to create the server (and thus the bind()
> call) and begin the active listening in separate steps, but we don't
> have that functionality in 3.6, our current minimum.
> 
> Therefore ... Add a temporary workaround that allows the synchronous
> version of the client to bind the socket in advance, guaranteeing that
> there will be a UNIX socket in the filesystem ready for the QEMU client
> to connect to without a race condition.
> 
> (Yes, it's a bit ugly. Fixing it more nicely will have to wait until our
> minimum Python version is 3.7+.)
> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  python/qemu/aqmp/legacy.py   |  3 +++
>  python/qemu/aqmp/protocol.py | 41 +++++++++++++++++++++++++++++++++---
>  2 files changed, 41 insertions(+), 3 deletions(-)
> 
> diff --git a/python/qemu/aqmp/legacy.py b/python/qemu/aqmp/legacy.py
> index 0890f95b16..6baa5f3409 100644
> --- a/python/qemu/aqmp/legacy.py
> +++ b/python/qemu/aqmp/legacy.py
> @@ -56,6 +56,9 @@ def __init__(self, address: SocketAddrT,
>          self._address = address
>          self._timeout: Optional[float] = None
>  
> +        if server:
> +            self._aqmp._bind_hack(address)  # pylint: 
> disable=protected-access

I feel that this is the only part that really makes it ugly. Do you
really think this way is so bad that we can't make it an official public
interface in the library?

Kevin