lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Copyright (C) 2003-2015 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2003. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #ifndef _BITS_ATOMIC_H |
| 20 | #define _BITS_ATOMIC_H 1 |
| 21 | |
| 22 | /* We have by default no support for atomic operations. So define |
| 23 | them non-atomic. If this is a problem somebody will have to come |
| 24 | up with real definitions. */ |
| 25 | |
| 26 | /* The only basic operation needed is compare and exchange. */ |
| 27 | #define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \ |
| 28 | ({ __typeof (mem) __gmemp = (mem); \ |
| 29 | __typeof (*mem) __gret = *__gmemp; \ |
| 30 | __typeof (*mem) __gnewval = (newval); \ |
| 31 | \ |
| 32 | if (__gret == (oldval)) \ |
| 33 | *__gmemp = __gnewval; \ |
| 34 | __gret; }) |
| 35 | |
| 36 | #define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \ |
| 37 | ({ __typeof (mem) __gmemp = (mem); \ |
| 38 | __typeof (*mem) __gnewval = (newval); \ |
| 39 | \ |
| 40 | *__gmemp == (oldval) ? (*__gmemp = __gnewval, 0) : 1; }) |
| 41 | |
| 42 | #endif /* bits/atomic.h */ |