Re: [libvirt] [RFC 0/1] convert virStorageSource to GObject
On 10/15/19 9:55 AM, Daniel P. Berrangé wrote:
On Tue, Oct 15, 2019 at 09:42:45AM -0300, Daniel Henrique Barboza
wrote:
> I was hoping to quickly re-send the qemu_driver cleanups I've
> sent some time ago, now using Glib. I started by attempting to
> change the first VIR_AUTOUNREF() call in qemu_driver.c to
> g_autoptr(), which happens to be a virStorageSourcePtr type,
> then I realized that it wasn't that simple.
It should be that simple with this commit:
commit 667ff797e8eb8d82f30ab430216a8d2eef6b915a
Author: Daniel P. Berrangé <berrange(a)redhat.com>
Date: Fri Oct 4 17:14:10 2019 +0100
src: add support for g_autoptr with virObject instances
we should be able to use g_autoptr for any virObject, without
having to lock-step convert to GObject.
What actual problem did you find ?
I failed to notice this commit. Just tried it again and it worked.
What happened yesterday was that I attempted to do a simple
VIR_AUTOUNREF -> g_autopt replace, faced compile errors and then, since
I didn't notice this commit about, I assumed "I guess I need to convert
this guy to GObject".
In fact, the compile error happened because g_autoptr() does not operate
with a 'Ptr' type - something that I learned only during the conversion
process.
Well, hopefully this patch can serve as a baseline for a future
conversion for
this object type. Guess I can go back safely to re-send the cleanup
patches tha
are already pending in the ML hehehe
> Following up the instructions found on commit 16121a88a7, I started
> the conversion. Then 'make check' started to fail because some
> calls to virObjectRef/virObjectUnref were still remaining
> in the code, messing up stuff related with mirrorChain in
> qemu_blockjob.c. Turns out it was easier to burn through all the
> instances and change them to use GLib.
Yes, if you convert from virObject to GObject, you *must*
convert all virObjectRef/Unref calls at that time.
> This is being sent as RFC because x-I am aware that docs/hacking.html
> mentions that we shouldn't mix up certain GLib macros with Libvirt
> ones, thus I am uncertain of whether I have messed up or not.
> 'make check' works, did a few sanity checks with libvirtd as
> well.
Yes, the need to not mix g_auto* with VIR_AUTO*, is why I did commit
667ff797e8eb8d82f30ab430216a8d2eef6b915a to let you use g_autoptr
with virObject, without first converting to GObject.
What if there are other object types in the same function using the VIR
macros?
For example, inside qemu_driver.c: qemuDomainBlockCopyCommon:
VIR_AUTOUNREF(virQEMUDriverConfigPtr) cfg =
virQEMUDriverGetConfig(driver);
const char *format = NULL;
bool mirror_reuse = !!(flags & VIR_DOMAIN_BLOCK_COPY_REUSE_EXT);
bool mirror_shallow = !!(flags & VIR_DOMAIN_BLOCK_COPY_SHALLOW);
bool existing = mirror_reuse;
qemuBlockJobDataPtr job = NULL;
VIR_AUTOUNREF(virStorageSourcePtr) mirror = mirrorsrc;
bool blockdev = virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV);
bool mirror_initialized = false;
VIR_AUTOPTR(qemuBlockStorageSourceChainData) data = NULL;
VIR_AUTOPTR(qemuBlockStorageSourceChainData) crdata = NULL;
Let's say that I change the virStorageSourcePtr up there to
g_autoptr(virStorageSource) mirror = mirrorsrc;
As long as there are no VIR macros acting in the 'mirror' variable, is
it to use g_autoptr
there even when everyone else is using VIR_AUTO* macros?
Thanks,
DHB
Regards,
Daniel