Re: Sdbusplus-based Shared Library

[Ratan Gupta <ratagupt@linux.vnet.ibm.com>]

Hi Andrew,

We raised this concern around an year back with patrick but that time it 
was told we have limited set of users for such classes,

Let it be replicate but now as the code size is getting increased we 
should look for some common library for such classes.

Regards

Ratan Gupta


On Tuesday 27 March 2018 11:17 AM, Andrew Jeffery wrote:
> On Tue, 20 Mar 2018, at 06:03, Patrick Venture wrote:
>> On Mon, Mar 19, 2018 at 11:24 AM, Tanous, Ed <ed.tanous@intel.com> wrote:
>>> Have you tried prototyping to see how much space you'll save?  I suspect it won't be a lot for a few reasons.
>>>
>>> 1. A lot of sdbusplus is template instantiations, and unless we forward declare a number of base template instantiations for use in the shared library, most of the application code will end up in the binary anyway.
>>> 2. Sdbus calls into libsystemd, which is already a shared library.
>>> 3. The filesystem is already compressed, so I suspect that any duplicated methods that aren't inlined will have the same binary code pattern and get duplicated by the squashfs filesystem.
>>>
>>> Those are all the reasons why I haven't really looked into it for the dbus stuff;  I can't speak to the timer stuff, but I suspect the wins in size there are going to be small.
>>>
>>> Normal disclaimer, on this specific library, I haven't prototyped anything, just done back of the napkin guesses, so I could very easily be missing something here.
>>>
>> So my thinking wasn't about reducing size of the binary but rather
>> reducing the toil of maintaining multiple implementations of the same
>> code.
>>
> I'm on board with this idea. There are a bunch of utility classes defined for RAII that are (were) used in phosphor-mboxd that would be much better off defined in some library where they can be reused.
>
> Has anyone looked at this beyond what's in the thread?
>
> Cheers,
>
> Andrew
>