Re: [Qemu-devel] [RFC PATCH 0/8] Remove stub mon-protocol-event for block

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

于 2013/9/12 17:31, Paolo Bonzini 写道:
> Il 12/09/2013 11:15, Wenchao Xia ha scritto:
>> This series will remove the usage of symbols of mon-protocol-event in
>> qemu-img, qemu-nbd and qemu-io, in short remove the connetion for block
>> layer.
>>
>> Background:
>>    I am tring to decouple block layer code with other unnnessary components,
>> and in ./stub there many symbols that qemu-img linked as fake implemtion.
>> As a first step, I am decouple monitor with block layer code, this is the
>> first part of it.
>>    There are still other stub symbols for monitor, which will be solved later.
>> It seems error handlering is also link with those symbols, and will adjust
>> that.
>>
>> Wenchao Xia (8):
>>    1 block: use type MonitorEvent directly
>>    2 block: do not include monitor.h in block.c
>>    3 qapi: move MonitorEvent define
>>    4 qapi: rename MonitorEvent to QEvent
>>    5 block: add a callback layer for common functions
>>    6 block: replace monitor_protocol_event() with callback
>>    7 block: do not include monitor.h
>>    7 stubs: remove mon-protocol-event.o in stub obj
>>
>>   block.c                    |   22 ++++++++++++++++++----
>>   block/qcow2-refcount.c     |    4 +++-
>>   blockjob.c                 |   10 ++++++++--
>>   include/block/block.h      |   12 ++++++++++++
>>   include/block/block_int.h  |    3 +--
>>   include/monitor/monitor.h  |   40 ++--------------------------------------
>>   include/qapi/qmp/qevent.h  |   41 +++++++++++++++++++++++++++++++++++++++++
>>   include/qapi/qmp/types.h   |    1 +
>>   monitor.c                  |   12 ++++++------
>>   stubs/Makefile.objs        |    1 -
>>   stubs/mon-protocol-event.c |    2 +-
>>   tests/Makefile             |    3 ++-
>>   ui/vnc.c                   |    2 +-
>>   vl.c                       |    4 ++++
>>   14 files changed, 100 insertions(+), 57 deletions(-)
>>   create mode 100644 include/qapi/qmp/qevent.h
>>
> Patches 1-4 look good.  I'm not sure of the advantage of the last four,
> however.  The ugly part of monitor_protocol_event is not really the
> stub, but the dependency on QObject.
I think replacing QObject with QAPI types is another issue we could 
improve. The last
foure patches tries decouple monitor code with block layer code from 
build time.
The files in ./stubs is needed since some symbols are needed in some 
program which don't
need it really, and I think, that tips the code are not organized very 
well in .c file level.
After removing ./stubs, the code will be more clear. And as a by- 
prodcut, the components
in qemu will have a clear boundary, and I can select several components 
to form library,
and qemu can naturlly link with it.

> So, in my opinion a more interesting approach would be to describe
> events using QAPI types.  Generating the events would require a small
> amount of code to build QObjects manually, because the event syntax
> doesn't match exactly a QAPI union, but that is only a technical detail.
>
> Paolo
>