[PATCH 05/10] d3dx9: Implement d3dx_effect_DeleteParameterBlock().

[Matteo Bruni]

On Tue, Nov 12, 2019 at 8:19 PM Paul Gofman <gofmanp at gmail.com> wrote:
>
> On 11/12/19 21:51, Matteo Bruni wrote:
> > On Thu, Nov 7, 2019 at 10:19 PM Paul Gofman <gofmanp at gmail.com> wrote:
> >
> >> @@ -4121,11 +4129,27 @@ static HRESULT WINAPI d3dx_effect_ApplyParameterBlock(ID3DXEffect *iface, D3DXHA
> >>  #if D3DX_SDK_VERSION >= 26
> >>  static HRESULT WINAPI d3dx_effect_DeleteParameterBlock(ID3DXEffect *iface, D3DXHANDLE parameter_block)
> >>  {
> > Any idea what is the behavior with version < 26? Was the allocated
> > memory just dropped on the floor?
>
> As I interpret the test, the parameter block is deleted upon effect
> delete (I decided so by checking object reference: the texture looses
> the last effect's reference when the effect is deleted without explicit
> parameter block deletion). So I guess the earlier versions did not have
> explicit DeleteParameterBlock(), but all allocated block got deleted on
> effect release.

Right, it makes sense.

> >> -    struct d3dx_effect *This = impl_from_ID3DXEffect(iface);
> >> +    struct d3dx_parameter_block *block = get_valid_parameter_block(parameter_block);
> >> +    struct d3dx_effect *effect = impl_from_ID3DXEffect(iface);
> >> +    struct d3dx_parameter_block *b;
> >>
> >> -    FIXME("(%p)->(%p): stub\n", This, parameter_block);
> >> +    TRACE("iface %p, parameter_block %p.\n", iface, parameter_block);
> >>
> >> -    return E_NOTIMPL;
> >> +    if (!block)
> >> +        return D3DERR_INVALIDCALL;
> >> +
> >> +    LIST_FOR_EACH_ENTRY(b, &effect->parameter_block_list, struct d3dx_parameter_block, entry)
> >> +    {
> >> +        if (b == block)
> >> +        {
> >> +            list_remove(&b->entry);
> >> +            free_parameter_block(b);
> >> +            return D3D_OK;
> >> +        }
> >> +    }
> >> +
> >> +    WARN("Block is not found in issued block list, not freeing memory.\n");
> >> +    return D3DERR_INVALIDCALL;
> >>  }
> >>  #endif
> > What happens if the parameter block is currently active?
>
> I am not sure what do you mean by active block? As far as understood,
> the block does not have active state: applying it is equivalent to
> separately setting all the parameters it contains, the block is just a
> collection of parameter values. The block which is currently being
> recorded cannot be freed here, as the application did not get its handle
> yet, it will get it only when it calls EndParameterBlock(), and at that
> moment the block is finalized and the recording of the block stops, it
> is not a current recording block anymore. If you mean what happens if
> someone will try to apply parameter block which was previously deleted
> here, I did not test that, but I don't see yet how this can result in
> anything but use after free in native d3dx.

Eh, good point. Also you're already freeing the current block if the
effect is released while recording so all is fine.