Summary:
This uses Eina_Cow to implement support for rarely used features
in EO objects. This covers:
- composite objects (eg. UI widgets: combobox, text, video, win)
- vtable for efl_object_override
- del_intercept
All of these features are quite tricky to get right and while
very useful, should still be used with great care. With this patch,
the size of an _Eo_Object struct comes down from 80 bytes (rounded
up from 72b) to 64 bytes (rounded up from 56b) on 64 bits.
Also I haven't measured precisely but I don't expect any performance
impact since the COW data is more likely to remain in L1/L2 cache,
as the default one will be used most often. Unfortunately, the
results of "make benchmark" have been quite inconsistent over
multiple runs.
This saves ~64kb in elementary_test (>4k objects) at the cost of
~100 calls to COW write (del intercept on some events).
@optimization
Reviewers: raster, cedric
Differential Revision: https://phab.enlightenment.org/D4796
86d1f2b6cd