MALLOC(2)                                               MALLOC(2)

     NAME
          malloc, free, realloc, calloc - memory allocator

     SYNOPSIS
          #include <u.h>
          #include <libc.h>

          void* malloc(long size)

          void  free(void *ptr)

          void* realloc(void *ptr, long size)

          void* calloc(long nelem, long elsize)

     DESCRIPTION
          Malloc and free provide a simple memory allocation package.
          Malloc returns a pointer to a new block of at least size
          bytes.  The block is suitably aligned for storage of any
          type of object.  No two active pointers from malloc will
          have the same value.

          The argument to free is a pointer to a block previously
          allocated by malloc; this space is made available for fur-
          ther allocation.  It is legal to free a null pointer; the
          effect is a no-op.

          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.  The call realloc(0, size) means the
          same as `malloc(size)'.

          Calloc allocates space for an array of nelem elements of
          size elsize. The space is initialized to zeros.  Free frees
          such a block.

        Alef
          Except for calloc, these routines are available from Alef;
          they use the same arena as alloc.  Malloc and realloc exe-
          cute a check when they fail, rather than return nil.  Memory
          returned by malloc is cleared.  Realloc does not guarantee
          new memory is cleared unless ptr is nil.

     SOURCE
          /sys/src/libc/port/malloc.c

     SEE ALSO
          brk(2)

     MALLOC(2)                                               MALLOC(2)

     DIAGNOSTICS
          Malloc, realloc and calloc return 0 if there is no available
          memory.  Errstr is likely to be set.

     BUGS
          The different specification of calloc is bizarre.

          User errors can corrupt the storage arena.  The most common
          gaffes are (1) freeing an already freed block, (2) storing
          beyond the bounds of an allocated block, and (3) freeing
          data that was not obtained from the allocator.  When malloc
          and free detect such corruption, they abort.