Re: [Qemu-devel] [PATCH v5 1/2] qom: Add can_be_deleted callback to UserCreatableClass

[Lin Ma <lma@suse.com>]

在 2015年03月28日 01:20, Igor Mammedov 写道:
> On Sat, 28 Mar 2015 00:55:29 +0800
> Lin Ma <lma@suse.com> wrote:
>
>> If backends implement the can_be_deleted and it returns false,
>> Then the qmp_object_del won't delete the given backends.
>>
>> Signed-off-by: Lin Ma <lma@suse.com>
>> ---
>>   include/qom/object_interfaces.h | 14 ++++++++++++++
>>   qmp.c                           |  5 +++++
>>   qom/object_interfaces.c         | 14 ++++++++++++++
>>   3 files changed, 33 insertions(+)
>>
>> diff --git a/include/qom/object_interfaces.h b/include/qom/object_interfaces.h
>> index b792283..012b653 100644
>> --- a/include/qom/object_interfaces.h
>> +++ b/include/qom/object_interfaces.h
>> @@ -25,6 +25,8 @@ typedef struct UserCreatable {
>>    * UserCreatableClass:
>>    * @parent_class: the base class
>>    * @complete: callback to be called after @obj's properties are set.
>> + * @can_be_deleted: callback to be called before an object is removed
>> + * to check if @obj can be removed safely.
>>    *
>>    * Interface is designed to work with -object/object-add/object_add
>>    * commands.
>> @@ -47,6 +49,7 @@ typedef struct UserCreatableClass {
>>   
>>       /* <public> */
>>       void (*complete)(UserCreatable *uc, Error **errp);
>> +    bool (*can_be_deleted)(UserCreatable *uc, Error **errp);
>>   } UserCreatableClass;
>>   
>>   /**
>> @@ -59,4 +62,15 @@ typedef struct UserCreatableClass {
>>    * nothing.
>>    */
>>   void user_creatable_complete(Object *obj, Error **errp);
>> +
>> +/**
>> + * user_creatable_can_be_deleted:
>> + * @obj: the object whose can_be_deleted() method is called if defined
> s/obj/uc/
> s/defined/implemented/
>
>> + * @errp: if an error occurs, a pointer to an area to store the error
>> + *
>> + * Wrapper to call can_be_deleted() method if one of types it's inherited
>> + * from implements USER_CREATABLE interface, otherwise the call does
>> + * nothing.
> drop ", otherwise the call does nothing"
>
>> +bool user_creatable_can_be_deleted(Object *obj, Error **errp);
> [...]
>>   
>> +bool user_creatable_can_be_deleted(Object *obj, Error **errp)
>> +{
>> +
>> +    UserCreatableClass *ucc;
>> +    UserCreatable *uc = USER_CREATABLE(obj);
> Function description doesn't match what it does, I mean part
> "otherwise the call does nothing."
>
> How about changing prototype to:
>
> bool user_creatable_can_be_deleted(UserCreatable *uc, Error **errp)
>
> and calling it in qmp.c like:
>    user_creatable_can_be_deleted(USER_CREATABLE(obj), errp);
That makes sense.

But If so, Does prototype of user_creatable_complete need to be changed 
as well by a new patch?