NAME

        rdsalloc - memory allocation function

SYNOPSYS

        #include "rdsnnn.h"
          char ∗rdsalloc( Size, Heap )
            unsigned int Size;
            char         Heap;

PARAMETER

       Size                memory size to allocate

       Heap                takes  the  values  RDS_ALLOC_BLOCK  or  RDS_ALLOC_HEAP  (two  defined
                           constants).

DESCRIPTION

       The rdsalloc function can do memory allocation by block or by heap. If the user  wants  to
       allocate  by  block,  he  sets the parameter Heap to the constant RDS_ALLOC_BLOCK else, he
       wants to allocate by heap so the parameter Heap is set to RDS_ALLOC_HEAP.  If rdsalloc  is
       used  with  the  constant  RDS_ALLOC_BLOCK  then  rdsalloc  is used as standard language C
       function malloc().  If the user allocates by heap then : At the first  allocation  of  the
       block  of  size  the  parameter  ´Size´,  a  heap  of  size  multiple of the block Size is
       allocated. When another allocation of the same size is done then if  the  the  heap  isn't
       full  then  a  pointer  (of  size=´Size´)  is  returned else a new heap is allocated and a
       pointer returned. Like this, the user does really one allocation (he has many pointers) to
       minimize  fragmentation.  Heap  allocation  is  usefull  if  the user has to allocate many
       pointers of the same size (ex: rdsrec_list structure).

       Note: Memory place allocated is set to NULL.

RETURN VALUE

       pointer to the allocated memory is returned.

ERRORS

       "Rds202: rdsalloc error, can't continue !"
              it's impossible to allocate the memory size desired.

EXAMPLE

             #include "rdsnnn.h"
          main()
           {
              rdsrec_list ∗Rectangle;
              rdsfig_list ∗Figure;
            Rectangle =
                 (rdsrec_list ∗) rdsalloc (sizeof(rdsrec_list ∗),RDS_ALLOC_HEAP);
            Figure    =
                 (rdsfig_list ∗) rdsalloc (sizeof(rdsfig_list ∗),RDS_ALLOC_BLOCK);
           }

SEE ALSO

       librds, rdsfree