[Chicken-users] Heap shrinkage, -:hs

[Sven Hartrumpf]

Hi all.

I would like to experiment with heap shrinking (-:hs) for long
running, memory/GC intensive processes.

I checked runtime.c and I read the following shrink condition:

count < percentage(percentage(heap_size, C_heap_shrinkage), 
DEFAULT_HEAP_SHRINKAGE_USED)

This shrink condition means that the _new_ heap size is used for deciding
shrinkage and not the _current_ heap size.
This would imply that heap usage must be <= 12.5 % to lead to a heap shrink
because C_heap_shrinkage is 50% and DEFAULT_HEAP_SHRINKAGE_USED is 25 %.
This is very unlikely for most applications :-)
How about:

count < percentage(heap_size, DEFAULT_HEAP_SHRINKAGE_USED)  ?

Furthermore, I would like to request a runtime option (-:hu ?) to modify
DEFAULT_HEAP_SHRINKAGE_USED leading to a variable like C_heap_shrinkage_used.

Ciao
Sven