/* 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 , 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 #include /* 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 */