rom/exec/allocvec.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Allocate some memory.
   6     Lang: english
   7 */
   8 #include "exec_intern.h"
   9 #include <aros/libcall.h>
  10 #include "memory.h"
  11 #include <proto/exec.h>
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16
  17         AROS_LH2(APTR, AllocVec,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(IPTR,  byteSize,     D0),
  21         AROS_LHA(ULONG, requirements, D1),
  22
  23 /*  LOCATION */
  24         struct ExecBase *, SysBase, 114, Exec)
  25
  26 /*  FUNCTION
  27         Allocate some memory from the sytem memory pool with the given
  28         requirements and without the need to memorize the actual size
  29         of the block.
  30
  31     INPUTS
  32         byteSize     - Number of bytes you want to get
  33         requirements - Type of memory
  34
  35     RESULT
  36         A pointer to the number of bytes you wanted or NULL if the memory
  37         couldn't be allocated
  38
  39     NOTES
  40
  41     EXAMPLE
  42
  43     BUGS
  44
  45     SEE ALSO
  46         FreeVec()
  47
  48     INTERNALS
  49
  50 ******************************************************************************/
  51 {
  52     AROS_LIBFUNC_INIT
  53
  54     UBYTE *ret;
  55
  56     /* 0-sized allocation results in returning NULL (API guarantee) */
  57     if(!byteSize)
  58         return NULL;
  59
  60     /* Add room for stored size. */
  61     byteSize+=AROS_ALIGN(sizeof(IPTR));
  62
  63     /* Get the memory. */
  64     ret=(UBYTE *)AllocMem(byteSize,requirements);
  65
  66     /* If there's not enough memory left return immediately. */
  67     if(ret==NULL)
  68         return NULL;
  69
  70     /* Store size */
  71     *(IPTR *)ret=byteSize;
  72
  73     /* return free space */
  74     return ret+AROS_ALIGN(sizeof(IPTR));
  75     AROS_LIBFUNC_EXIT
  76 } /* AllocVec */
  77