- to enable this feature, compile with --with-profile=debug
- the mid tables and tables are write protected after modifications,
you will segfault if you mess with them
- because of mmap PAGE_SIZE alignement and added magic header, almost a
memory page is wasted per table and mid table allocation.
- reducing the number of tables per mid table and the number of entries
per table solves this.
- pack active flag and generation nbr in an _Eo_Id_Entry struct
- replace Eina_Trash with a fifo which lives in mmaped memory owned by eo_id.
- fifo uses indexes instead of pointers to spare memory
- never used entries are served first, then those in the fifo
are reused, thus we ensure that a freed entry won't soon be reused.
use of an array of the below struct instead of 3 separate arrays
leads to better cache performance and smaller memory usage
typedef struct
{
_Eo *ptr;
unsigned int active : 1;
unsigned int generation : BITS_FOR_GENERATION_COUNTER;
} _Eo_Id_Entry;
Summary: This feature replaces Eo pointers with ids to prevent bad usage
or reuse of these pointers. It doesn't change API.
The mechanism uses tables storing the real pointers to the objects.
See the src/lib/eo/eo_ptr_indirection.c file for more details on the
mechanism.
Jérémy Zurcher
Carsten Haitzler
Daniel Zaoui