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Diffstat (limited to 'include')
| -rw-r--r-- | include/atomic.h | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/include/atomic.h b/include/atomic.h new file mode 100644 index 000000000..8a23f6ee9 --- /dev/null +++ b/include/atomic.h @@ -0,0 +1,261 @@ +/* Internal macros for atomic operations for GNU C Library. + Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _ATOMIC_H +#define _ATOMIC_H 1 + +#include <stdlib.h> + +#include <bits/atomic.h> + +/* Wrapper macros to call pre_NN_post (mem, ...) where NN is the + bit width of *MEM. The calling macro puts parens around MEM + and following args. */ +#define __atomic_val_bysize(pre, post, mem, ...) \ + ({ \ + __typeof (*mem) __result; \ + if (sizeof (*mem) == 1) \ + __result = pre##_8_##post (mem, __VA_ARGS__); \ + else if (sizeof (*mem) == 2) \ + __result = pre##_16_##post (mem, __VA_ARGS__); \ + else if (sizeof (*mem) == 4) \ + __result = pre##_32_##post (mem, __VA_ARGS__); \ + else if (sizeof (*mem) == 8) \ + __result = pre##_64_##post (mem, __VA_ARGS__); \ + else \ + abort (); \ + __result; \ + }) +#define __atomic_bool_bysize(pre, post, mem, ...) \ + ({ \ + int __result; \ + if (sizeof (*mem) == 1) \ + __result = pre##_8_##post (mem, __VA_ARGS__); \ + else if (sizeof (*mem) == 2) \ + __result = pre##_16_##post (mem, __VA_ARGS__); \ + else if (sizeof (*mem) == 4) \ + __result = pre##_32_##post (mem, __VA_ARGS__); \ + else if (sizeof (*mem) == 8) \ + __result = pre##_64_##post (mem, __VA_ARGS__); \ + else \ + abort (); \ + __result; \ + }) + + +/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL. + Return the old *MEM value. */ +#if !defined atomic_compare_and_exchange_val_acq \ + && defined __arch_compare_and_exchange_val_32_acq +# define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \ + __atomic_val_bysize (__arch_compare_and_exchange_val,acq, \ + mem, newval, oldval) +#endif + + +#ifndef atomic_compare_and_exchange_val_rel +# define atomic_compare_and_exchange_val_rel(mem, newval, oldval) \ + atomic_compare_and_exchange_val_acq (mem, newval, oldval) +#endif + + +/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL. + Return zero if *MEM was changed or non-zero if no exchange happened. */ +#ifndef atomic_compare_and_exchange_bool_acq +# ifdef __arch_compare_and_exchange_bool_32_acq +# define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \ + __atomic_bool_bysize (__arch_compare_and_exchange_bool,acq, \ + mem, newval, oldval) +# else +# define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \ + ({ /* Cannot use __oldval here, because macros later in this file might \ + call this macro with __oldval argument. */ \ + __typeof (oldval) __old = (oldval); \ + atomic_compare_and_exchange_val_acq (mem, newval, __old) != __old; \ + }) +# endif +#endif + + +#ifndef atomic_compare_and_exchange_bool_rel +# define atomic_compare_and_exchange_bool_rel(mem, newval, oldval) \ + atomic_compare_and_exchange_bool_acq (mem, newval, oldval) +#endif + + +/* Store NEWVALUE in *MEM and return the old value. */ +#ifndef atomic_exchange_acq +# define atomic_exchange_acq(mem, newvalue) \ + ({ __typeof (*(mem)) __oldval; \ + __typeof (mem) __memp = (mem); \ + __typeof (*(mem)) __value = (newvalue); \ + \ + do \ + __oldval = (*__memp); \ + while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ + __value, \ + __oldval),\ + 0)); \ + \ + __oldval; }) +#endif + +#ifndef atomic_exchange_rel +# define atomic_exchange_rel(mem, newvalue) atomic_exchange_acq (mem, newvalue) +#endif + + +/* Add VALUE to *MEM and return the old value of *MEM. */ +#ifndef atomic_exchange_and_add +# define atomic_exchange_and_add(mem, value) \ + ({ __typeof (*(mem)) __oldval; \ + __typeof (mem) __memp = (mem); \ + __typeof (*(mem)) __value = (value); \ + \ + do \ + __oldval = (*__memp); \ + while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ + __oldval \ + + __value,\ + __oldval),\ + 0)); \ + \ + __oldval; }) +#endif + + +#ifndef atomic_add +# define atomic_add(mem, value) (void) atomic_exchange_and_add ((mem), (value)) +#endif + + +#ifndef atomic_increment +# define atomic_increment(mem) atomic_add ((mem), 1) +#endif + + +#ifndef atomic_increment_val +# define atomic_increment_val(mem) (atomic_exchange_and_add ((mem), 1) + 1) +#endif + + +/* Add one to *MEM and return true iff it's now zero. */ +#ifndef atomic_increment_and_test +# define atomic_increment_and_test(mem) \ + (atomic_exchange_and_add ((mem), 1) + 1 == 0) +#endif + + +#ifndef atomic_decrement +# define atomic_decrement(mem) atomic_add ((mem), -1) +#endif + + +#ifndef atomic_decrement_val +# define atomic_decrement_val(mem) (atomic_exchange_and_add ((mem), -1) - 1) +#endif + + +/* Subtract 1 from *MEM and return true iff it's now zero. */ +#ifndef atomic_decrement_and_test +# define atomic_decrement_and_test(mem) \ + (atomic_exchange_and_add ((mem), -1) == 1) +#endif + + +/* Decrement *MEM if it is > 0, and return the old value. */ +#ifndef atomic_decrement_if_positive +# define atomic_decrement_if_positive(mem) \ + ({ __typeof (*(mem)) __oldval; \ + __typeof (mem) __memp = (mem); \ + \ + do \ + { \ + __oldval = *__memp; \ + if (__builtin_expect (__oldval <= 0, 0)) \ + break; \ + } \ + while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ + __oldval \ + - 1, \ + __oldval),\ + 0));\ + __oldval; }) +#endif + + +#ifndef atomic_add_negative +# define atomic_add_negative(mem, value) \ + ({ __typeof (value) __aan_value = (value); \ + atomic_exchange_and_add (mem, __aan_value) < -__aan_value; }) +#endif + + +#ifndef atomic_add_zero +# define atomic_add_zero(mem, value) \ + ({ __typeof (value) __aaz_value = (value); \ + atomic_exchange_and_add (mem, __aaz_value) == -__aaz_value; }) +#endif + + +#ifndef atomic_bit_set +# define atomic_bit_set(mem, bit) \ + (void) atomic_bit_test_set(mem, bit) +#endif + + +#ifndef atomic_bit_test_set +# define atomic_bit_test_set(mem, bit) \ + ({ __typeof (*(mem)) __oldval; \ + __typeof (mem) __memp = (mem); \ + __typeof (*(mem)) __mask = ((__typeof (*(mem))) 1 << (bit)); \ + \ + do \ + __oldval = (*__memp); \ + while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ + __oldval \ + | __mask, \ + __oldval),\ + 0)); \ + \ + __oldval & __mask; }) +#endif + + +#ifndef atomic_full_barrier +# define atomic_full_barrier() __asm ("" ::: "memory") +#endif + + +#ifndef atomic_read_barrier +# define atomic_read_barrier() atomic_full_barrier () +#endif + + +#ifndef atomic_write_barrier +# define atomic_write_barrier() atomic_full_barrier () +#endif + + +#ifndef atomic_delay +# define atomic_delay() do { /* nothing */ } while (0) +#endif + +#endif /* atomic.h */ |