Re: [PATCH 1/6] Python: close the log file kept by QEMUMachine before reading it

[Wainer dos Santos Moschetta]

Hi,

On 2/11/21 7:01 PM, Cleber Rosa wrote:
> Closing a file that is open for writing, and then reading from it
> sounds like a better idea than the opposite, given that the content
> will be flushed.
>
> Reference: https://docs.python.org/3/library/io.html#io.IOBase.close
> Signed-off-by: Cleber Rosa <crosa@redhat.com>
> ---
>   python/qemu/machine.py | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/python/qemu/machine.py b/python/qemu/machine.py
> index 7a40f4604b..6e44bda337 100644
> --- a/python/qemu/machine.py
> +++ b/python/qemu/machine.py
> @@ -337,12 +337,12 @@ class QEMUMachine:
>               self._qmp.close()
>               self._qmp_connection = None
>   
> -        self._load_io_log()
> -
>           if self._qemu_log_file is not None:
>               self._qemu_log_file.close()
>               self._qemu_log_file = None
>   
> +        self._load_io_log()
> +


IMO it's a too fragile fix. It needs the `self._qemu_log_file.close()` 
being called before `self._load_io_log()` but a future change can make 
this condition unmet again. Maybe you could document that in the code. 
Or change the `_load_io_log()` to close the log file if it is open (also 
document it in code).

- Wainer

>           self._qemu_log_path = None
>   
>           if self._temp_dir is not None: