Re: [Qemu-devel] [Qemu-trivial] [PATCH] Fix some memory leaks in test-visitor-serialization

[Stefan Hajnoczi <stefanha@gmail.com>]

On Wed, Mar 27, 2013 at 04:47:15PM -0500, mdroth wrote:
> On Tue, Mar 26, 2013 at 05:46:55PM -0400, Stefan Berger wrote:
> > This patch fixes some of the memory leaks in
> > test-visitor-serialization but not all of them.
> > 
> > Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> > 
> > ---
> >  tests/test-visitor-serialization.c |   17 ++++++++++++++---
> >  1 file changed, 14 insertions(+), 3 deletions(-)
> > 
> > Index: qemu-git.pt/tests/test-visitor-serialization.c
> > ===================================================================
> > --- qemu-git.pt.orig/tests/test-visitor-serialization.c
> > +++ qemu-git.pt/tests/test-visitor-serialization.c
> > @@ -258,6 +258,7 @@ static void test_primitives(gconstpointe
> >      g_assert(pt_copy != NULL);
> >      if (pt->type == PTYPE_STRING) {
> >          g_assert_cmpstr(pt->value.string, ==, pt_copy->value.string);
> > +        g_free((char *)pt_copy->value.string);
> >      } else if (pt->type == PTYPE_NUMBER) {
> >          /* we serialize with %f for our reference visitors, so
> > rather than fuzzy
> >           * floating math to test "equality", just compare the
> > formatted values
> > @@ -275,6 +276,7 @@ static void test_primitives(gconstpointe
> > 
> >      ops->cleanup(serialize_data);
> >      g_free(args);
> > +    g_free(pt_copy);
> >  }
> > 
> >  static void test_struct(gconstpointer opaque)
> > @@ -637,6 +639,7 @@ PrimitiveType pt_values[] = {
> >  /* visitor-specific op implementations */
> > 
> >  typedef struct QmpSerializeData {
> > +    QObject *obj;
> >      QmpOutputVisitor *qov;
> >      QmpInputVisitor *qiv;
> >  } QmpSerializeData;
> > @@ -656,10 +659,10 @@ static void qmp_deserialize(void **nativ
> >  {
> >      QmpSerializeData *d = datap;
> >      QString *output_json =
> > qobject_to_json(qmp_output_get_qobject(d->qov));
> > -    QObject *obj = qobject_from_json(qstring_get_str(output_json));
> > 
> > +    d->obj = qobject_from_json(qstring_get_str(output_json));
> >      QDECREF(output_json);
> > -    d->qiv = qmp_input_visitor_new(obj);
> > +    d->qiv = qmp_input_visitor_new(d->obj);
> >      visit(qmp_input_get_visitor(d->qiv), native_out, errp);
> >  }
> > 
> > @@ -668,9 +671,13 @@ static void qmp_cleanup(void *datap)
> >      QmpSerializeData *d = datap;
> >      qmp_output_visitor_cleanup(d->qov);
> >      qmp_input_visitor_cleanup(d->qiv);
> > +    qobject_decref(d->obj);
> 
> We can actually call this just after passing the qobject to
> qmp_input_visitor_new(), which will lead to it getting cleaned up
> in qmp_input_visitor_cleanup(). That way we wouldn't need to hold
> on to the reference in d->obj.
> 
> But this works too, and looks like string visitor still requires
> we hang on to the reference to free it, so either way:
> 
> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>

Please decref right away like mdroth suggests so the obj field doesn't
need to be introduced.

Stefan