| 1 | /* Copyright (C) 1991, 1992 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Library General Public License as |
| 6 | published by the Free Software Foundation; either version 2 of the |
| 7 | License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Library General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Library General Public |
| 15 | License along with the GNU C Library; see the file COPYING.LIB. If |
| 16 | not, write to the Free Software Foundation, Inc., 675 Mass Ave, |
| 17 | Cambridge, MA 02139, USA. */ |
| 18 | |
| 19 | #include "mmalloc.h" |
| 20 | |
| 21 | PTR |
| 22 | mmemalign (md, alignment, size) |
| 23 | PTR md; |
| 24 | size_t alignment; |
| 25 | size_t size; |
| 26 | { |
| 27 | PTR result; |
| 28 | unsigned long int adj; |
| 29 | struct alignlist *l; |
| 30 | struct mdesc *mdp; |
| 31 | |
| 32 | size = ((size + alignment - 1) / alignment) * alignment; |
| 33 | |
| 34 | if ((result = mmalloc (md, size)) != NULL) |
| 35 | { |
| 36 | adj = RESIDUAL (result, alignment); |
| 37 | if (adj != 0) |
| 38 | { |
| 39 | mdp = MD_TO_MDP (md); |
| 40 | for (l = mdp -> aligned_blocks; l != NULL; l = l -> next) |
| 41 | { |
| 42 | if (l -> aligned == NULL) |
| 43 | { |
| 44 | /* This slot is free. Use it. */ |
| 45 | break; |
| 46 | } |
| 47 | } |
| 48 | if (l == NULL) |
| 49 | { |
| 50 | l = (struct alignlist *) mmalloc (md, sizeof (struct alignlist)); |
| 51 | if (l == NULL) |
| 52 | { |
| 53 | mfree (md, result); |
| 54 | return (NULL); |
| 55 | } |
| 56 | } |
| 57 | l -> exact = result; |
| 58 | result = l -> aligned = (char *) result + alignment - adj; |
| 59 | l -> next = mdp -> aligned_blocks; |
| 60 | mdp -> aligned_blocks = l; |
| 61 | } |
| 62 | } |
| 63 | return (result); |
| 64 | } |