[REBOL] Re: Memory issues
From: ptretter::norcom2000::com at: 26-Jan-2001 14:44
Thanks for the quick and details response ELAN. I am quickly putting your
comments into practice in my script.
Thanks Again.
Paul Tretter
----- Original Message -----
From: "Elan" <[rebol--techscribe--com]>
To: <[rebol-list--rebol--com]>
Sent: Friday, January 26, 2001 2:04 PM
Subject: [REBOL] Re: Memory issues
> Hi Paul,
>
> Paul Tretter wrote:
>
> > recycle
>
> REBOL has automatic garbage collection and will free previously
> allocated memory that is no longer needed by itself. You can optionally
> instruct REBOL to free up memory by using recycle. I would use recycle
> in two (three) situations, namely when I want to better control at which
> point in time REBOL spends machine cycles on freeing previously
> allocated memory
> a) When I know that I am about to do something that is very memory
> intensive, and I want to avoid having REBOL free up memory repeatedly
> while it is evaluating my memory intensive functions; So I force REBOL
> to reclaim unused memory hoping that this will provide for a large
> enough available memory pool and REBOL will not have to interrupt the
> evalution of the following instructions in order to free up memory;
> b) When I know that I have just used up a huge amount of memory, and I
> want to avoid having REBOL repeatedly reclaim unused memory as needed
> during the evaluation of the following code;
> c) This is a combination of a and b: During the repreated evaluation of
> memory intensive functions I want to better control at which point
> memory that is no longer needed should be freed.
>
> > clear
>
> The clear function empties a series value, such as a block or a string.
> Elements whose reference count has fallen to zero will be automatically
> garbage collected (or garbage collection can be forced with recycel).
>
> > free
>
> When you load a shared library (or dll) under /Command then the
> resources associated with that library must be explicitly freed using
> free. These resources are not included in the garbage collection, since
> REBOL has no way of knowing if the DLL or shared library is still using
> that resource internally.
>
> > unset
>
> Unset dis-asscoiates a word from its value. Unset reduces the reference
> count of a value, and if the reference count has dropped to 0 the value
> will be garbage collected, and the memory it occupies will be freed.
>
> Comparing clear to unset: If I use clear I reclaim the memory used by
> the elemnts of a series value, but the series value itself, and the word
> associated with it, continue to exist and occupy memory. If I use unset
> instead of clear, then not only will the element be garbage collected,
> but in addition, the series value itself is disposed of, and the word is
> no longer associated with a value.
>
> Hope this helps,
>
> Elan
>
> >
> > Did I miss any?
> >
> > What are the advantages or disadvantages of each. 'Free apears to be
only available in /Command version. I am very interested in this with a
script that I am working on that is getting a bit memory intensive.
