With openssl_pkey what you are doing may be correct. I was talking about
the general case regarding refs.
On Tue, 2008-05-27 at 13:43 +0530, Manjula Peiris wrote:
> On Tue, 2008-05-27 at 12:05 +0530, Uthaiyashankar wrote:
> > Supun Kamburugamuva wrote:
> > > Hi,
> > >
> > > We use a ref count to keep track of the references to a openssl_pkey_t and
> > > use it in the openssl_pkey_free method. In the openssl_pkey_create method
> > > we
> > > are setting the ref count to 0. But since we are returning a pointer, ref
> > > count should be set to 1. Also the free method assumes that in the create
> > > method it will be set to one.
> > >
> > > This is the code in the free method.
> > >
> > > if(--(pkey->ref) > 0){
> > > return AXIS2_SUCCESS ;
> > > }
> > >
> > > Now lets assume we are having two pointers to the structure. One pointer
> > > is
> > > created when the structure is create and other is when we copy the
> > > pointer.
> > > But now our ref counter is 1 (In create method we set it to 0).
> > >
> > > Lets say we free those two pointers respectively. In both these free
> > > method
> > > calls the above if statement will return false and the structure will be
> > > free twice (double free). So we need to set the ref = 1 in the
> > > openssl_pkey_create methods?
>
> This will fail in Neethi. For example let's take the Algorithmsuite
> struct. Say we set the ref = 1 at the creation. The Binding struct keeps
> a pointer to Algotithmsuite struct so ref = 2. since Algorithmsuite is
> an assertion the Assertion struct also keeps a pointer so ref = 3. But
> Algorithmsuite free calls only twice. That is from Assertion_free and
> binding_free. So in this case it will not be freed. IMHO we can't define
> a hard rule to set ref=1 when creating the struct. If we are going to do
> that then we should have done it at the beginning, otherwise we need to
> do some major changes. The developer can decide whether to set it to 0
> or 1 by looking at how it exists. If it is always inside another struct
> and freed from some other struct better to keep the ref = 0. Otherwise
> better to keep ref = 1.
>
> > >
> >
> > +1. One other possibility is to increase reference just after creating.
> > This is how all the other references are working. But I prefer to do
> > that in Create method itself.
> >
> > Regards,
> > Shankar.
> > > Any comments?
> > >
> > > Supun..
> > >
> > >
> >
>
