Memory Allocation Library Functions            mapmalloc(3MALLOC)

NAME
     mapmalloc - memory allocator

SYNOPSIS
     cc [ flag ... ] file ... -lmapmalloc [ library ... ]
     #include <stdlib.h>

     void *malloc(size_t size);

     void *calloc(size_t nelem, size_t elsize);

     void free(void * ptr);

     void *realloc(void *ptr, size_t size);

DESCRIPTION
     The collection of   malloc  routines  in  this  library  use
     mmap(2)  instead  of   sbrk(2) for acquiring new heap space.
     The routines in this library are  intended to be  used  only
     if  necessary, when applications must call  sbrk(), but need
     to call other library routines that might call  malloc.  The
     algorithms  used  by  these  routines are not sophisticated.
     There is no reclaiming of memory.

     malloc() and free() provide a simple general-purpose  memory
     allocation package.

     malloc() returns a pointer to a block of at least size bytes
     suitably aligned for any use.

     The argument to free() is a pointer to  a  block  previously
     allocated  by  malloc(), calloc() or realloc(). If  ptr is a
     NULL pointer, no action occurs.

     Undefined results will occur if the space assigned  by  mal-
     loc()  is  overrun  or  if  some  random number is handed to
     free().

     calloc() allocates space for an array of nelem  elements  of
     size elsize. The space is initialized to zeros.

     realloc() changes the size of the block pointed to by ptr to
     size  bytes  and  returns  a pointer to the (possibly moved)
     block. The contents will be unchanged up to  the  lesser  of
     the  new  and  old sizes. If  ptr is NULL, realloc() behaves
     like malloc() for the specified size. If  size is  zero  and
     ptr is not a null pointer, the object pointed to is freed.

     Each of the allocation routines returns a pointer  to  space
     suitably  aligned  (after  possible  pointer  coercion)  for
     storage of any type of object.

SunOS 5.8           Last change: 26 Mar 1998                    1

Memory Allocation Library Functions            mapmalloc(3MALLOC)

     malloc() and realloc() will fail  if  there  is  not  enough
     available memory.

     Entry points  for  malloc_debug(),  mallocmap(),  mallopt(),
     mallinfo(),  memalign(),  and  valloc(), are empty routines,
     and are provided only to protect the user from  mixing  mal-
     loc() functions from different implementations.

RETURN VALUES
     If there is no available memory,  malloc(),  realloc(),  and
     calloc() return a null pointer. When realloc() returns NULL,
     the block pointed to by   ptr  is  left  intact.  If   size,
     nelem,  or   elsize  is  0, a unique pointer to the arena is
     returned.

FILES
     /usr/lib/libmapmalloc

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | Safe                        |
    |_____________________________|_____________________________|

SEE ALSO
     brk(2), getrlimit(2), mmap(2), realloc(3C), malloc(3MALLOC),
     attributes(5)

SunOS 5.8           Last change: 26 Mar 1998                    2