POS

[Bill House]

Christopher J. Vogt wrote:
>
>My only opinion on this is that I want to be sure to be able to *NOT* use
>POS.
>
>Similarly, wrt GC, I want to be able to allocate/deallocate memory myself
>on occasion, and not have the GC involved.  Of course I want the GC
>avaiable, and used on most of my objects.

FWIW, here's an excerpt of docs about the way objects interact with GC under
the Gambit-C Scheme compiler. Among the interesting bits is the concept of
having different GC algorithms responsible for different memory stores:

====
Object representation.

Memory allocated Scheme objects can be allocated using one of three
allocation strategies:

   Permanently allocated:
     These objects, called 'permanent objects' for short, are never
     moved or reclaimed, and all pointers to memory allocated
     objects they contain must point to permanent objects.  As a
     consequence, the GC does not have to scan permanent objects.
     Permanent objects can be allocated on the C heap, but they are
     typically allocated in C global variables and structures that are
     set up when the program starts up or when a module is dynamically
     loaded.

   Still dynamically allocated:
     These objects, called 'still objects' for short, are allocated on
     the C heap.  Still objects are never moved but they can be reclaimed by
     the GC.  A mark-and-sweep GC is used to garbage-collect still objects.

   Movable dynamically allocated:
     These objects, called 'movable objects' for short, are allocated
     in an area of memory that is managed by a compacting GC.  The GC can
     move and reclaim movable objects.

======

Bill House
--
http://www.dazsi.com
The views expressed are mine alone,
unless you agree with me.