Re: [Sbcl-help] Garbage collection for server with user sessions

[Brett v. de S. <bv...@as...>]

>>> OK, I understand that there is no lisp version of free().
>>> However, would it help the garbage collection if I applied
>>> something like the following to my session data at the close
>>> of a session:
>>> 
>>> (defun dereference (obj)
>>>       (cond ((consp obj)
>>>              (dereference (car obj))
>>>              (dereference (cdr obj))
>>>              (setf (car obj) nil)
>>>              (setf (cdr ojb) nil))
>>>        ;; add similar actions for arrays, structs, etc.
>>> ))
>> 
>> To a degree, yes.
>> 
>> Doing it always for everything is almost certainly a bad idea, but
>> doing things like CLRHASH for hash-tables or FILL for vectors can be
>> worthwhile.
>> 
>> It all depends: if cleaning out pointers means you're writing to
>> write-protected pages it is going to be a loss -- but if those pages
>> are dirty already, it is probably a win.
>
>I'm not sure it would help at all.  

Indeed, dereferencing objects only made the behavior of 
the garbage collector somewhat worse.  Since it does "stop-and-copy"
garbage collection steps, cleaning out pointers doesn't help.

Brett