Re: [Qemu-devel] [PATCH 1/1] char: Add a QemuChrHandlers struct to initialise chardev handlers

[Kevin Wolf]

Am 10.02.2012 18:22, schrieb Anthony Liguori:
> On 02/10/2012 11:09 AM, Amit Shah wrote:
>> On (Fri) 10 Feb 2012 [07:28:19], Anthony Liguori wrote:
>>> On 02/10/2012 07:19 AM, Amit Shah wrote:
>>>> Instead of passing each handler in the qemu_add_handlers() function,
>>>> create a struct of handlers that can be passed to the function instead.
>>>>
>>>> Signed-off-by: Amit Shah<address@hidden>
>>>
>>> Why?
>>
>> It's a good cleanup.
>>
>>> It's not a win in terms of code size.  If you plan on introducing
>>> additional handlers, perhaps you should include this in that series
>>> where it's more appropriately justified.
>>>
>>> As a change on it's own, it doesn't seem to make a lot of sense.
>>
>> Makes the code much easier to look at.  Can't really compare on code
>> size, since there's zero change in the resulting binary, but the code
>> just becomes more readable and manageable.
> 
> It's not more readable IMHO.  You've taken function call arguments from the 
> place they naturally belong (in the function call) and placed them somewhere 
> else.
> 
> More importantly, this isn't a pattern we use in QEMU anywhere.

The obvious next step is to replace
CharDriverState.chr_can_read/read/event with a CharDriverState.ops that
refers to a CharDriverHandler struct, and suddenly you have a pattern
that is used a lot in QEMU (and that indeed increases readability in my
opinion).

Kevin