| [2] | 1 | /* Internal macros for atomic operations for GNU C Library. |
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| 2 | Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. |
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| 5 | |
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| 6 | The GNU C Library is free software; you can redistribute it and/or |
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| 7 | modify it under the terms of the GNU Lesser General Public |
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| 8 | License as published by the Free Software Foundation; either |
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| 9 | version 2.1 of the License, or (at your option) any later version. |
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| 10 | |
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| 11 | The GNU C Library is distributed in the hope that it will be useful, |
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 14 | Lesser General Public License for more details. |
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| 15 | |
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| 16 | You should have received a copy of the GNU Lesser General Public |
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| 17 | License along with the GNU C Library; if not, write to the Free |
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| 18 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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| 19 | 02111-1307 USA. */ |
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| 20 | |
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| 21 | #ifndef _ATOMIC_H |
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| 22 | #define _ATOMIC_H 1 |
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| 23 | |
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| 24 | #include <stdlib.h> |
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| 25 | |
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| 26 | #include <bits/atomic.h> |
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| 27 | |
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| 28 | /* Wrapper macros to call pre_NN_post (mem, ...) where NN is the |
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| 29 | bit width of *MEM. The calling macro puts parens around MEM |
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| 30 | and following args. */ |
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| 31 | #define __atomic_val_bysize(pre, post, mem, ...) \ |
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| 32 | ({ \ |
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| 33 | __typeof (*mem) __result; \ |
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| 34 | if (sizeof (*mem) == 1) \ |
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| 35 | __result = pre##_8_##post (mem, __VA_ARGS__); \ |
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| 36 | else if (sizeof (*mem) == 2) \ |
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| 37 | __result = pre##_16_##post (mem, __VA_ARGS__); \ |
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| 38 | else if (sizeof (*mem) == 4) \ |
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| 39 | __result = pre##_32_##post (mem, __VA_ARGS__); \ |
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| 40 | else if (sizeof (*mem) == 8) \ |
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| 41 | __result = pre##_64_##post (mem, __VA_ARGS__); \ |
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| 42 | else \ |
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| 43 | abort (); \ |
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| 44 | __result; \ |
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| 45 | }) |
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| 46 | #define __atomic_bool_bysize(pre, post, mem, ...) \ |
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| 47 | ({ \ |
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| 48 | int __result; \ |
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| 49 | if (sizeof (*mem) == 1) \ |
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| 50 | __result = pre##_8_##post (mem, __VA_ARGS__); \ |
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| 51 | else if (sizeof (*mem) == 2) \ |
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| 52 | __result = pre##_16_##post (mem, __VA_ARGS__); \ |
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| 53 | else if (sizeof (*mem) == 4) \ |
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| 54 | __result = pre##_32_##post (mem, __VA_ARGS__); \ |
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| 55 | else if (sizeof (*mem) == 8) \ |
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| 56 | __result = pre##_64_##post (mem, __VA_ARGS__); \ |
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| 57 | else \ |
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| 58 | abort (); \ |
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| 59 | __result; \ |
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| 60 | }) |
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| 61 | |
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| 62 | |
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| 63 | /* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL. |
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| 64 | Return the old *MEM value. */ |
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| 65 | #if !defined atomic_compare_and_exchange_val_acq \ |
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| 66 | && defined __arch_compare_and_exchange_val_32_acq |
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| 67 | # define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \ |
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| 68 | __atomic_val_bysize (__arch_compare_and_exchange_val,acq, \ |
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| 69 | mem, newval, oldval) |
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| 70 | #endif |
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| 71 | |
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| 72 | |
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| 73 | #ifndef atomic_compare_and_exchange_val_rel |
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| 74 | # define atomic_compare_and_exchange_val_rel(mem, newval, oldval) \ |
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| 75 | atomic_compare_and_exchange_val_acq (mem, newval, oldval) |
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| 76 | #endif |
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| 77 | |
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| 78 | |
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| 79 | /* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL. |
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| 80 | Return zero if *MEM was changed or non-zero if no exchange happened. */ |
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| 81 | #ifndef atomic_compare_and_exchange_bool_acq |
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| 82 | # ifdef __arch_compare_and_exchange_bool_32_acq |
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| 83 | # define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \ |
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| 84 | __atomic_bool_bysize (__arch_compare_and_exchange_bool,acq, \ |
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| 85 | mem, newval, oldval) |
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| 86 | # else |
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| 87 | # define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \ |
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| 88 | ({ /* Cannot use __oldval here, because macros later in this file might \ |
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| 89 | call this macro with __oldval argument. */ \ |
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| 90 | __typeof (oldval) __old = (oldval); \ |
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| 91 | atomic_compare_and_exchange_val_acq (mem, newval, __old) != __old; \ |
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| 92 | }) |
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| 93 | # endif |
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| 94 | #endif |
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| 95 | |
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| 96 | |
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| 97 | #ifndef atomic_compare_and_exchange_bool_rel |
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| 98 | # define atomic_compare_and_exchange_bool_rel(mem, newval, oldval) \ |
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| 99 | atomic_compare_and_exchange_bool_acq (mem, newval, oldval) |
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| 100 | #endif |
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| 101 | |
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| 102 | |
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| 103 | /* Store NEWVALUE in *MEM and return the old value. */ |
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| 104 | #ifndef atomic_exchange_acq |
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| 105 | # define atomic_exchange_acq(mem, newvalue) \ |
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| 106 | ({ __typeof (*(mem)) __oldval; \ |
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| 107 | __typeof (mem) __memp = (mem); \ |
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| 108 | __typeof (*(mem)) __value = (newvalue); \ |
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| 109 | \ |
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| 110 | do \ |
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| 111 | __oldval = (*__memp); \ |
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| 112 | while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ |
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| 113 | __value, \ |
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| 114 | __oldval),\ |
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| 115 | 0)); \ |
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| 116 | \ |
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| 117 | __oldval; }) |
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| 118 | #endif |
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| 119 | |
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| 120 | #ifndef atomic_exchange_rel |
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| 121 | # define atomic_exchange_rel(mem, newvalue) atomic_exchange_acq (mem, newvalue) |
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| 122 | #endif |
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| 123 | |
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| 124 | |
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| 125 | /* Add VALUE to *MEM and return the old value of *MEM. */ |
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| 126 | #ifndef atomic_exchange_and_add |
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| 127 | # define atomic_exchange_and_add(mem, value) \ |
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| 128 | ({ __typeof (*(mem)) __oldval; \ |
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| 129 | __typeof (mem) __memp = (mem); \ |
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| 130 | __typeof (*(mem)) __value = (value); \ |
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| 131 | \ |
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| 132 | do \ |
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| 133 | __oldval = (*__memp); \ |
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| 134 | while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ |
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| 135 | __oldval \ |
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| 136 | + __value,\ |
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| 137 | __oldval),\ |
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| 138 | 0)); \ |
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| 139 | \ |
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| 140 | __oldval; }) |
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| 141 | #endif |
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| 142 | |
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| 143 | |
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| 144 | #ifndef atomic_add |
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| 145 | # define atomic_add(mem, value) (void) atomic_exchange_and_add ((mem), (value)) |
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| 146 | #endif |
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| 147 | |
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| 148 | |
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| 149 | #ifndef atomic_increment |
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| 150 | # define atomic_increment(mem) atomic_add ((mem), 1) |
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| 151 | #endif |
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| 152 | |
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| 153 | |
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| 154 | #ifndef atomic_increment_val |
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| 155 | # define atomic_increment_val(mem) (atomic_exchange_and_add ((mem), 1) + 1) |
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| 156 | #endif |
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| 157 | |
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| 158 | |
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| 159 | /* Add one to *MEM and return true iff it's now zero. */ |
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| 160 | #ifndef atomic_increment_and_test |
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| 161 | # define atomic_increment_and_test(mem) \ |
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| 162 | (atomic_exchange_and_add ((mem), 1) + 1 == 0) |
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| 163 | #endif |
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| 164 | |
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| 165 | |
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| 166 | #ifndef atomic_decrement |
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| 167 | # define atomic_decrement(mem) atomic_add ((mem), -1) |
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| 168 | #endif |
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| 169 | |
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| 170 | |
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| 171 | #ifndef atomic_decrement_val |
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| 172 | # define atomic_decrement_val(mem) (atomic_exchange_and_add ((mem), -1) - 1) |
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| 173 | #endif |
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| 174 | |
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| 175 | |
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| 176 | /* Subtract 1 from *MEM and return true iff it's now zero. */ |
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| 177 | #ifndef atomic_decrement_and_test |
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| 178 | # define atomic_decrement_and_test(mem) \ |
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| 179 | (atomic_exchange_and_add ((mem), -1) == 1) |
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| 180 | #endif |
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| 181 | |
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| 182 | |
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| 183 | /* Decrement *MEM if it is > 0, and return the old value. */ |
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| 184 | #ifndef atomic_decrement_if_positive |
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| 185 | # define atomic_decrement_if_positive(mem) \ |
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| 186 | ({ __typeof (*(mem)) __oldval; \ |
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| 187 | __typeof (mem) __memp = (mem); \ |
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| 188 | \ |
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| 189 | do \ |
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| 190 | { \ |
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| 191 | __oldval = *__memp; \ |
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| 192 | if (__builtin_expect (__oldval <= 0, 0)) \ |
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| 193 | break; \ |
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| 194 | } \ |
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| 195 | while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ |
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| 196 | __oldval \ |
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| 197 | - 1, \ |
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| 198 | __oldval),\ |
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| 199 | 0));\ |
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| 200 | __oldval; }) |
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| 201 | #endif |
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| 202 | |
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| 203 | |
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| 204 | #ifndef atomic_add_negative |
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| 205 | # define atomic_add_negative(mem, value) \ |
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| 206 | ({ __typeof (value) __aan_value = (value); \ |
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| 207 | atomic_exchange_and_add (mem, __aan_value) < -__aan_value; }) |
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| 208 | #endif |
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| 209 | |
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| 210 | |
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| 211 | #ifndef atomic_add_zero |
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| 212 | # define atomic_add_zero(mem, value) \ |
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| 213 | ({ __typeof (value) __aaz_value = (value); \ |
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| 214 | atomic_exchange_and_add (mem, __aaz_value) == -__aaz_value; }) |
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| 215 | #endif |
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| 216 | |
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| 217 | |
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| 218 | #ifndef atomic_bit_set |
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| 219 | # define atomic_bit_set(mem, bit) \ |
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| 220 | (void) atomic_bit_test_set(mem, bit) |
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| 221 | #endif |
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| 222 | |
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| 223 | |
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| 224 | #ifndef atomic_bit_test_set |
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| 225 | # define atomic_bit_test_set(mem, bit) \ |
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| 226 | ({ __typeof (*(mem)) __oldval; \ |
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| 227 | __typeof (mem) __memp = (mem); \ |
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| 228 | __typeof (*(mem)) __mask = ((__typeof (*(mem))) 1 << (bit)); \ |
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| 229 | \ |
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| 230 | do \ |
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| 231 | __oldval = (*__memp); \ |
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| 232 | while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ |
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| 233 | __oldval \ |
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| 234 | | __mask, \ |
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| 235 | __oldval),\ |
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| 236 | 0)); \ |
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| 237 | \ |
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| 238 | __oldval & __mask; }) |
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| 239 | #endif |
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| 240 | |
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| 241 | |
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| 242 | #ifndef atomic_full_barrier |
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| 243 | # define atomic_full_barrier() __asm ("" ::: "memory") |
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| 244 | #endif |
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| 245 | |
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| 246 | |
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| 247 | #ifndef atomic_read_barrier |
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| 248 | # define atomic_read_barrier() atomic_full_barrier () |
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| 249 | #endif |
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| 250 | |
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| 251 | |
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| 252 | #ifndef atomic_write_barrier |
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| 253 | # define atomic_write_barrier() atomic_full_barrier () |
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| 254 | #endif |
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| 255 | |
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| 256 | |
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| 257 | #ifndef atomic_delay |
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| 258 | # define atomic_delay() do { /* nothing */ } while (0) |
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| 259 | #endif |
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| 260 | |
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| 261 | #endif /* atomic.h */ |
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