[libvirt] [PATCH 4/8] qemu: Don't repeat virDomainObjEndAPI in qemuDomainBlockPull

[Eric Blake]

On 9/27/19 1:33 AM, Peter Krempa wrote:
> On Thu, Sep 26, 2019 at 17:02:49 -0500, Eric Blake wrote:
>> On 9/26/19 10:51 AM, Peter Krempa wrote:
>>> Add a 'cleanup' label and use jumps as we do in other places.
>>>
>>> Signed-off-by: Peter Krempa <pkrempa at redhat.com>
>>> ---
>>>    src/qemu/qemu_driver.c | 17 ++++++++++-------
>>>    1 file changed, 10 insertions(+), 7 deletions(-)
>>
>>> + cleanup:
>>> +    virDomainObjEndAPI(&vm);
>>> +    return ret;
>>>    }
>>
>> Is there any way to make virDomainObjEndAPI() replaceable by AUTO framework?
> 
> It will probably require a new macro or a new type to avoid breaking
> semantics we've established.
> 

> 
> We could introduce something like VIR_AUTORELEASE and VIR_AUTOUNLOCK for
> use with virOjbectLockable-based objects. The former would then do the
> required virObjectUnlock and then virObjectUnref. The latter is for
> parity in cases when the lock should be dropped.
> 
> I'll propose these and see how it will go.

glibc has GMutexLocker which is a way to release a lock on all exit 
paths after its use (or to release the lock early).
https://developer.gnome.org/glib/stable/glib-Threads.html#g-mutex-locker-new
You can use that for inspiration.


-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org