/* Internal macros for atomic operations for GNU C Library. Copyright (C) 2002, 2003 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 /* 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) \ ({ __typeof (*mem) __result; \ if (sizeof (*mem) == 1) \ __result = __arch_compare_and_exchange_val_8_acq (mem, newval, oldval);\ else if (sizeof (*mem) == 2) \ __result = __arch_compare_and_exchange_val_16_acq (mem, newval,oldval);\ else if (sizeof (*mem) == 4) \ __result = __arch_compare_and_exchange_val_32_acq (mem, newval,oldval);\ else if (sizeof (*mem) == 8) \ __result = __arch_compare_and_exchange_val_64_acq (mem, newval,oldval);\ else \ abort (); \ __result; }) #endif #ifndef atomic_compare_and_exchange_val_rel # define atomic_compare_and_exchange_val_rel(mem, oldval, newval) \ atomic_compare_and_exchange_val_acq (mem, oldval, newval) #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) \ ({ __typeof (__arch_compare_and_exchange_bool_32_acq (mem, 0, 0)) __result; \ if (sizeof (*mem) == 1) \ __result = __arch_compare_and_exchange_bool_8_acq (mem, newval, \ oldval); \ else if (sizeof (*mem) == 2) \ __result = __arch_compare_and_exchange_bool_16_acq (mem, newval, \ oldval); \ else if (sizeof (*mem) == 4) \ __result = __arch_compare_and_exchange_bool_32_acq (mem, newval, \ oldval); \ else if (sizeof (*mem) == 8) \ __result = __arch_compare_and_exchange_bool_64_acq (mem, newval, \ oldval); \ else \ abort (); \ __result; }) # 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, oldval, newval) \ atomic_compare_and_exchange_bool_acq (mem, oldval, newval) #endif /* Store NEWVALUE in *MEM and return the old value. */ #ifndef atomic_exchange # define atomic_exchange(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 /* 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 /* Add one to *MEM and return true iff it's now nonzero. */ #ifndef atomic_increment_and_test # define atomic_increment_and_test(mem) \ (atomic_exchange_and_add (mem, 1) != 0) #endif #ifndef atomic_decrement # define atomic_decrement(mem) atomic_add (mem, -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) == 0) #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) \ (atomic_exchange_and_add (mem, value) < 0) #endif #ifndef atomic_add_zero # define atomic_add_zero(mem, value) \ (atomic_exchange_and_add (mem, value) == 0) #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 #endif /* atomic.h */