[Oberon] Fw: FPGA - Bitmaps.Mod

[Tomas Kral]

Hi Andreas, Joerg,

I have tried both methods suggested here.

(a) without tag declaration, simply calling
Kernel.New(b.base, SYSTEM.ADR(b.size));

(b) with tag declaration and persistence
tag.size := <size of your object to be allocated>;
tag.ext[0] := 0; tag.ext[1] := 0; tag.ext[2] := 0;
tag.ptr := -1;
Kernel.New(b.base, SYSTEM.ADR(tag.size))

They both seem to allocate a block of requested size, however when GC is
run, sometimes heap is inconsistent and `System.Watch' reports strange
values, e.g.
Heap speace -1111221223-1100000% 

Tomas 

On Fri, 7 Apr 2017 18:12:38 +0200
Andreas Pirklbauer <andreas_pirklbauer at yahoo.com> wrote:

> 
> Correction: This should read 'TypeDesc' of course, and not
> 'TypeTag' (which is the *address* of the TypeDesc).
> 
> From: Andreas Pirklbauer <andreas_pirklbauer at yahoo.com>
> To: ETH Oberon and Related Systems <oberon at lists.inf.ethz.ch> 
> 
> ...
> 
> You don't really need b) and c), so you could write something like:
> 
> 
>   TYPE TypeTag = RECORD size: LONGINT;
> 
>      ext: ARRAY 3 OF LONGINT;
> 
>      ptr: LONGINT;
> 
>      <other fields that you may want to add>
> 
>   END ;
> 
> 
> Then create the "type tag" by writing:
> 
> 
>   VAR tag: TypeTag;
> 
> 
> and initialise it with:
> 
> 
>   tag.size := <size of your object to be allocated>;
>   tag.ext[0] := 0; tag.ext[1] := 0; tag.ext[2] := 0;
>   tag.ptr := -1;
> 
> 
> 4. If you want your objects to be automatically collected by the
> Oberon garbage collector, you must make it globally reachable via a
> global pointer. Then they will appear in mod.ptr in the module block
> which are used as roots for the garbage collector. (Oberon uses all
> named pointer variables in existence as roots for the mark phase of
> the garbage collector. See Oberon.GC for the details. It simply calls
> Kernel.Mark(mod.ptr) for each loaded module mod.
> 
> 
> Andreas
> 
>  
> 
>