rdsalloc(3alc)

1RDSALLOC(3)                 RDS PHYSICAL FUNCTIONS                 RDSALLOC(3)
2
3
4

NAME

6        rdsalloc - memory allocation function
7

SYNOPSIS

9        #include "rdsnnn.h"
10          char ∗rdsalloc( Size, Heap )
11            unsigned int Size;
12            char         Heap;
13

PARAMETER

15       Size                memory size to allocate
16
17       Heap                takes  the values RDS_ALLOC_BLOCK or RDS_ALLOC_HEAP
18                           (two defined constants).
19

DESCRIPTION

21       The rdsalloc function can do memory allocation by block or by heap.  If
22       the  user wants to allocate by block, he sets the parameter Heap to the
23       constant RDS_ALLOC_BLOCK else, he wants to  allocate  by  heap  so  the
24       parameter  Heap is set to RDS_ALLOC_HEAP.  If rdsalloc is used with the
25       constant RDS_ALLOC_BLOCK then rdsalloc is used as standard  language  C
26       function  malloc().   If the user allocates by heap then : At the first
27       allocation of the block of size the parameter ´Size´, a  heap  of  size
28       multiple of the block Size is allocated. When another allocation of the
29       same size is done then if the the heap isn't full then  a  pointer  (of
30       size=´Size´)  is  returned  else  a new heap is allocated and a pointer
31       returned. Like this, the user does really one allocation (he  has  many
32       pointers)  to  minimize fragmentation. Heap allocation is useful if the
33       user has to allocate many pointers of the same  size  (ex:  rdsrec_list
34       structure).
35
36       Note: Memory place allocated is set to NULL.
37

RETURN VALUE

39       pointer to the allocated memory is returned.
40

ERRORS

42       "Rds202: rdsalloc error, can't continue !"
43              it's impossible to allocate the memory size desired.
44

EXAMPLE

46             #include "rdsnnn.h"
47          main()
48           {
49              rdsrec_list ∗Rectangle;
50              rdsfig_list ∗Figure;
51            Rectangle =
52                 (rdsrec_list ∗) rdsalloc (sizeof(rdsrec_list ∗),RDS_ALLOC_HEAP);
53            Figure    =
54                 (rdsfig_list ∗) rdsalloc (sizeof(rdsfig_list ∗),RDS_ALLOC_BLOCK);
55           }
56