Re: [Qemu-devel] [RFC PATCH V2 3/5] qapi script: add event support by qapi-event.py

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

于 2014/1/7 11:24, Wenchao Xia 写道:
>>>> +
>>>> +
>>>> +# Following are the functions that generate event behavior control
>>>> functions.
>>>> +# Those functions are put here in the qapi-event.c, since it need
>>>> to include
>>>> +# qapi-event.h for the event enum type declaration, put them in
>>>> other file
>>>> +# requiring other file include qapi-event.h, causing a cross
>>>> including. For
>>>> +# example: if we have qmp-event.c and qmp-event.h, then qmp-event.c
>>>> +# ->qmp-event.h->qapi-event.h, qapi-event.c->qmp-event.h. Another
>>>> problem
>>>> +# follow: test-qapi-event.c will meet event enum double declaration
>>>> since it
>>>> +# include both test-qapi-event.h and qmp-event.h. One solution is
>>>> putting event
>>>> +# enum declaration in a separate header file, but then qmp-event.h
>>>> need to
>>>> +# include test-qapi-event.h or qapi-event.h on compile time
>>>> condition. So the
>>>> +# easist way is, just generate them here.
>>>> +
>>>> +def generate_event_behavior_control_decl(event_enum_name):
>>>> +    ret = mcgen('''
>>>> +
>>>> +typedef void (*QAPIEventFuncEmit)(%(event_enum_name)s ev,
>>>> +                                  QDict *dict,
>>>> +                                  Error **errp);
>>
>> Why does the emit function need 'ev'? Doesn't 'dict' contain all the
>> info it needs? Also, it's better to rename it to 'event' or 'qmp_event'.
>>
>
>    ev is for rate limit. I didn't move rate limit logic from callback to
> internal, mainly because it is a generated function, which seems
> too complex. And the genrated function was not moved into a separte
> file mainly because the enum and including issue, see the comments
> in script above.
>    The problem is enum is changing, so the new file include it need
> to recompile, for example, test schema and qapi-schema.json may
> force recompile twice, I am not sure if it is good to do
> some tricks in build system.
>
   I am going to respin this series after sync with upstream.
"ev" will be removed, and will try use a runtime call to solve
issue above.