HP 3000 Manuals

HP Pascal/iX Reference Manual

HEAP_COMPACT 

HEAP_COMPACT is an HP Pascal Option.

When the HEAP_COMPACT compiler option is ON (and the HEAP_DISPOSE option
is also ON), free space in the heap is concatenated when the predefined
procedure dispose is called.

Syntax 

$HEAP_COMPACT {ON }$
              {OFF}

Default       OFF.

Location      At front.

The HEAP_COMPACT option is recommended for programs that manipulate many
dynamic record variables of different sizes via calls to the predefined
procedures new and dispose.  It allows free space to be merged and
reused.

Example 

     $HEAP_COMPACT ON; HEAP_DISPOSE ON$
     PROGRAM show_compact;
     TYPE
        big_rec = RECORD
                     f1 : ARRAY [1..4] OF integer;
                  END;
        small_rec = PACKED RECORD

                       f1 : integer;
                       f2 : integer;
                    END;
     VAR
       p1,p2 : ^mall_rec;
          p3 : ^big_rec;

     BEGIN
        new(p1);
        new(p2);
        dispose(p1);
        dispose(p2);
        new(p3);     {p3 is allocated in the space previously
                      occupied by p1 and p2}
     END.

MPE/iX 5.0 Documentation