/* Internal macros for atomic operations for GNU C Library.
- Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 2002-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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. */
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
#ifndef _ATOMIC_H
#define _ATOMIC_H 1
+/* This header defines three types of macros:
+
+ - atomic arithmetic and logic operation on memory. They all
+ have the prefix "atomic_".
+
+ - conditionally atomic operations of the same kinds. These
+ always behave identical but can be faster when atomicity
+ is not really needed since only one thread has access to
+ the memory location. In that case the code is slower in
+ the multi-thread case. The interfaces have the prefix
+ "catomic_".
+
+ - support functions like barriers. They also have the prefix
+ "atomic_".
+
+ Architectures must provide a few lowlevel macros (the compare
+ and exchange definitions). All others are optional. They
+ should only be provided if the architecture has specific
+ support for the operation.
+
+ As <atomic.h> macros are usually heavily nested and often use local
+ variables to make sure side-effects are evaluated properly, use for
+ macro local variables a per-macro unique prefix. This file uses
+ __atgN_ prefix where N is different in each macro. */
+
#include <stdlib.h>
-#include <bits/atomic.h>
+#include <atomic-machine.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 ((__typeof (*(mem))) *(mem)) __atg1_result; \
+ if (sizeof (*mem) == 1) \
+ __atg1_result = pre##_8_##post (mem, __VA_ARGS__); \
+ else if (sizeof (*mem) == 2) \
+ __atg1_result = pre##_16_##post (mem, __VA_ARGS__); \
+ else if (sizeof (*mem) == 4) \
+ __atg1_result = pre##_32_##post (mem, __VA_ARGS__); \
+ else if (sizeof (*mem) == 8) \
+ __atg1_result = pre##_64_##post (mem, __VA_ARGS__); \
+ else \
+ abort (); \
+ __atg1_result; \
+ })
+#define __atomic_bool_bysize(pre, post, mem, ...) \
+ ({ \
+ int __atg2_result; \
+ if (sizeof (*mem) == 1) \
+ __atg2_result = pre##_8_##post (mem, __VA_ARGS__); \
+ else if (sizeof (*mem) == 2) \
+ __atg2_result = pre##_16_##post (mem, __VA_ARGS__); \
+ else if (sizeof (*mem) == 4) \
+ __atg2_result = pre##_32_##post (mem, __VA_ARGS__); \
+ else if (sizeof (*mem) == 8) \
+ __atg2_result = pre##_64_##post (mem, __VA_ARGS__); \
+ else \
+ abort (); \
+ __atg2_result; \
+ })
/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL.
#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; })
+ __atomic_val_bysize (__arch_compare_and_exchange_val,acq, \
+ mem, newval, oldval)
+#endif
+
+
+#ifndef catomic_compare_and_exchange_val_acq
+# ifdef __arch_c_compare_and_exchange_val_32_acq
+# define catomic_compare_and_exchange_val_acq(mem, newval, oldval) \
+ __atomic_val_bysize (__arch_c_compare_and_exchange_val,acq, \
+ mem, newval, oldval)
+# else
+# define catomic_compare_and_exchange_val_acq(mem, newval, oldval) \
+ atomic_compare_and_exchange_val_acq (mem, newval, oldval)
+# endif
+#endif
+
+
+#ifndef catomic_compare_and_exchange_val_rel
+# ifndef atomic_compare_and_exchange_val_rel
+# define catomic_compare_and_exchange_val_rel(mem, newval, oldval) \
+ catomic_compare_and_exchange_val_acq (mem, newval, oldval)
+# else
+# define catomic_compare_and_exchange_val_rel(mem, newval, oldval) \
+ atomic_compare_and_exchange_val_rel (mem, newval, oldval)
+# endif
#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)
+# define atomic_compare_and_exchange_val_rel(mem, newval, oldval) \
+ atomic_compare_and_exchange_val_acq (mem, newval, oldval)
#endif
#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; })
+ __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; \
+ __typeof (oldval) __atg3_old = (oldval); \
+ atomic_compare_and_exchange_val_acq (mem, newval, __atg3_old) \
+ != __atg3_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)
+#ifndef catomic_compare_and_exchange_bool_acq
+# ifdef __arch_c_compare_and_exchange_bool_32_acq
+# define catomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
+ __atomic_bool_bysize (__arch_c_compare_and_exchange_bool,acq, \
+ mem, newval, oldval)
+# else
+# define catomic_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) __atg4_old = (oldval); \
+ catomic_compare_and_exchange_val_acq (mem, newval, __atg4_old) \
+ != __atg4_old; \
+ })
+# endif
#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); \
+#ifndef atomic_exchange_acq
+# define atomic_exchange_acq(mem, newvalue) \
+ ({ __typeof ((__typeof (*(mem))) *(mem)) __atg5_oldval; \
+ __typeof (mem) __atg5_memp = (mem); \
+ __typeof ((__typeof (*(mem))) *(mem)) __atg5_value = (newvalue); \
\
do \
- __oldval = (*__memp); \
- while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \
- __value, \
- __oldval),\
- 0)); \
+ __atg5_oldval = *__atg5_memp; \
+ while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg5_memp, __atg5_value, \
+ __atg5_oldval), 0)); \
\
- __oldval; })
+ __atg5_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_acq
+# ifdef atomic_exchange_and_add
+# define atomic_exchange_and_add_acq(mem, value) \
+ atomic_exchange_and_add (mem, value)
+# else
+# define atomic_exchange_and_add_acq(mem, value) \
+ ({ __typeof (*(mem)) __atg6_oldval; \
+ __typeof (mem) __atg6_memp = (mem); \
+ __typeof (*(mem)) __atg6_value = (value); \
+ \
+ do \
+ __atg6_oldval = *__atg6_memp; \
+ while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg6_memp, \
+ __atg6_oldval \
+ + __atg6_value, \
+ __atg6_oldval), 0)); \
+ \
+ __atg6_oldval; })
+# endif
+#endif
+
+#ifndef atomic_exchange_and_add_rel
+# define atomic_exchange_and_add_rel(mem, value) \
+ atomic_exchange_and_add_acq(mem, value)
+#endif
+
#ifndef atomic_exchange_and_add
# define atomic_exchange_and_add(mem, value) \
- ({ __typeof (*mem) __oldval; \
- __typeof (mem) __memp = (mem); \
- __typeof (*mem) __value = (value); \
+ atomic_exchange_and_add_acq(mem, value)
+#endif
+
+#ifndef catomic_exchange_and_add
+# define catomic_exchange_and_add(mem, value) \
+ ({ __typeof (*(mem)) __atg7_oldv; \
+ __typeof (mem) __atg7_memp = (mem); \
+ __typeof (*(mem)) __atg7_value = (value); \
\
do \
- __oldval = (*__memp); \
- while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \
- __oldval \
- + __value,\
- __oldval),\
- 0)); \
+ __atg7_oldv = *__atg7_memp; \
+ while (__builtin_expect \
+ (catomic_compare_and_exchange_bool_acq (__atg7_memp, \
+ __atg7_oldv \
+ + __atg7_value, \
+ __atg7_oldv), 0)); \
\
- __oldval; })
+ __atg7_oldv; })
+#endif
+
+
+#ifndef atomic_max
+# define atomic_max(mem, value) \
+ do { \
+ __typeof (*(mem)) __atg8_oldval; \
+ __typeof (mem) __atg8_memp = (mem); \
+ __typeof (*(mem)) __atg8_value = (value); \
+ do { \
+ __atg8_oldval = *__atg8_memp; \
+ if (__atg8_oldval >= __atg8_value) \
+ break; \
+ } while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg8_memp, __atg8_value,\
+ __atg8_oldval), 0)); \
+ } while (0)
+#endif
+
+
+#ifndef catomic_max
+# define catomic_max(mem, value) \
+ do { \
+ __typeof (*(mem)) __atg9_oldv; \
+ __typeof (mem) __atg9_memp = (mem); \
+ __typeof (*(mem)) __atg9_value = (value); \
+ do { \
+ __atg9_oldv = *__atg9_memp; \
+ if (__atg9_oldv >= __atg9_value) \
+ break; \
+ } while (__builtin_expect \
+ (catomic_compare_and_exchange_bool_acq (__atg9_memp, \
+ __atg9_value, \
+ __atg9_oldv), 0)); \
+ } while (0)
+#endif
+
+
+#ifndef atomic_min
+# define atomic_min(mem, value) \
+ do { \
+ __typeof (*(mem)) __atg10_oldval; \
+ __typeof (mem) __atg10_memp = (mem); \
+ __typeof (*(mem)) __atg10_value = (value); \
+ do { \
+ __atg10_oldval = *__atg10_memp; \
+ if (__atg10_oldval <= __atg10_value) \
+ break; \
+ } while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg10_memp, \
+ __atg10_value, \
+ __atg10_oldval), 0)); \
+ } while (0)
#endif
#ifndef atomic_add
-# define atomic_add(mem, value) (void) atomic_exchange_and_add (mem, value)
+# define atomic_add(mem, value) (void) atomic_exchange_and_add ((mem), (value))
+#endif
+
+
+#ifndef catomic_add
+# define catomic_add(mem, value) \
+ (void) catomic_exchange_and_add ((mem), (value))
#endif
#ifndef atomic_increment
-# define atomic_increment(mem) atomic_add (mem, 1)
+# define atomic_increment(mem) atomic_add ((mem), 1)
+#endif
+
+
+#ifndef catomic_increment
+# define catomic_increment(mem) catomic_add ((mem), 1)
+#endif
+
+
+#ifndef atomic_increment_val
+# define atomic_increment_val(mem) (atomic_exchange_and_add ((mem), 1) + 1)
+#endif
+
+
+#ifndef catomic_increment_val
+# define catomic_increment_val(mem) (catomic_exchange_and_add ((mem), 1) + 1)
#endif
-/* Add one to *MEM and return true iff it's now nonzero. */
+/* 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) != 0)
+ (atomic_exchange_and_add ((mem), 1) + 1 == 0)
#endif
#ifndef atomic_decrement
-# define atomic_decrement(mem) atomic_add (mem, -1)
+# define atomic_decrement(mem) atomic_add ((mem), -1)
+#endif
+
+
+#ifndef catomic_decrement
+# define catomic_decrement(mem) catomic_add ((mem), -1)
+#endif
+
+
+#ifndef atomic_decrement_val
+# define atomic_decrement_val(mem) (atomic_exchange_and_add ((mem), -1) - 1)
+#endif
+
+
+#ifndef catomic_decrement_val
+# define catomic_decrement_val(mem) (catomic_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) == 0)
+ (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); \
+ ({ __typeof (*(mem)) __atg11_oldval; \
+ __typeof (mem) __atg11_memp = (mem); \
\
do \
{ \
- __oldval = *__memp; \
- if (__builtin_expect (__oldval <= 0, 0)) \
+ __atg11_oldval = *__atg11_memp; \
+ if (__glibc_unlikely (__atg11_oldval <= 0)) \
break; \
} \
- while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \
- __oldval \
- - 1, \
- __oldval),\
- 0));\
- __oldval; })
+ while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg11_memp, \
+ __atg11_oldval - 1, \
+ __atg11_oldval), 0)); \
+ __atg11_oldval; })
#endif
#ifndef atomic_add_negative
-# define atomic_add_negative(mem, value) \
- (atomic_exchange_and_add (mem, value) < 0)
+# define atomic_add_negative(mem, value) \
+ ({ __typeof (value) __atg12_value = (value); \
+ atomic_exchange_and_add (mem, __atg12_value) < -__atg12_value; })
#endif
#ifndef atomic_add_zero
-# define atomic_add_zero(mem, value) \
- (atomic_exchange_and_add (mem, value) == 0)
+# define atomic_add_zero(mem, value) \
+ ({ __typeof (value) __atg13_value = (value); \
+ atomic_exchange_and_add (mem, __atg13_value) == -__atg13_value; })
#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)); \
+ ({ __typeof (*(mem)) __atg14_old; \
+ __typeof (mem) __atg14_memp = (mem); \
+ __typeof (*(mem)) __atg14_mask = ((__typeof (*(mem))) 1 << (bit)); \
\
do \
- __oldval = (*__memp); \
- while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \
- __oldval \
- | __mask, \
- __oldval),\
- 0)); \
+ __atg14_old = (*__atg14_memp); \
+ while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg14_memp, \
+ __atg14_old | __atg14_mask,\
+ __atg14_old), 0)); \
\
- __oldval & __mask; })
+ __atg14_old & __atg14_mask; })
#endif
+/* Atomically *mem &= mask. */
+#ifndef atomic_and
+# define atomic_and(mem, mask) \
+ do { \
+ __typeof (*(mem)) __atg15_old; \
+ __typeof (mem) __atg15_memp = (mem); \
+ __typeof (*(mem)) __atg15_mask = (mask); \
+ \
+ do \
+ __atg15_old = (*__atg15_memp); \
+ while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg15_memp, \
+ __atg15_old & __atg15_mask, \
+ __atg15_old), 0)); \
+ } while (0)
+#endif
+
+#ifndef catomic_and
+# define catomic_and(mem, mask) \
+ do { \
+ __typeof (*(mem)) __atg20_old; \
+ __typeof (mem) __atg20_memp = (mem); \
+ __typeof (*(mem)) __atg20_mask = (mask); \
+ \
+ do \
+ __atg20_old = (*__atg20_memp); \
+ while (__builtin_expect \
+ (catomic_compare_and_exchange_bool_acq (__atg20_memp, \
+ __atg20_old & __atg20_mask,\
+ __atg20_old), 0)); \
+ } while (0)
+#endif
+
+/* Atomically *mem &= mask and return the old value of *mem. */
+#ifndef atomic_and_val
+# define atomic_and_val(mem, mask) \
+ ({ __typeof (*(mem)) __atg16_old; \
+ __typeof (mem) __atg16_memp = (mem); \
+ __typeof (*(mem)) __atg16_mask = (mask); \
+ \
+ do \
+ __atg16_old = (*__atg16_memp); \
+ while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg16_memp, \
+ __atg16_old & __atg16_mask,\
+ __atg16_old), 0)); \
+ \
+ __atg16_old; })
+#endif
+
+/* Atomically *mem |= mask and return the old value of *mem. */
+#ifndef atomic_or
+# define atomic_or(mem, mask) \
+ do { \
+ __typeof (*(mem)) __atg17_old; \
+ __typeof (mem) __atg17_memp = (mem); \
+ __typeof (*(mem)) __atg17_mask = (mask); \
+ \
+ do \
+ __atg17_old = (*__atg17_memp); \
+ while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg17_memp, \
+ __atg17_old | __atg17_mask, \
+ __atg17_old), 0)); \
+ } while (0)
+#endif
+
+#ifndef catomic_or
+# define catomic_or(mem, mask) \
+ do { \
+ __typeof (*(mem)) __atg18_old; \
+ __typeof (mem) __atg18_memp = (mem); \
+ __typeof (*(mem)) __atg18_mask = (mask); \
+ \
+ do \
+ __atg18_old = (*__atg18_memp); \
+ while (__builtin_expect \
+ (catomic_compare_and_exchange_bool_acq (__atg18_memp, \
+ __atg18_old | __atg18_mask,\
+ __atg18_old), 0)); \
+ } while (0)
+#endif
+
+/* Atomically *mem |= mask and return the old value of *mem. */
+#ifndef atomic_or_val
+# define atomic_or_val(mem, mask) \
+ ({ __typeof (*(mem)) __atg19_old; \
+ __typeof (mem) __atg19_memp = (mem); \
+ __typeof (*(mem)) __atg19_mask = (mask); \
+ \
+ do \
+ __atg19_old = (*__atg19_memp); \
+ while (__builtin_expect \
+ (atomic_compare_and_exchange_bool_acq (__atg19_memp, \
+ __atg19_old | __atg19_mask,\
+ __atg19_old), 0)); \
+ \
+ __atg19_old; })
+#endif
#ifndef atomic_full_barrier
# define atomic_full_barrier() __asm ("" ::: "memory")
#ifndef atomic_read_barrier
-# define atomic_read_barrier() atomic_full_barrier()
+# define atomic_read_barrier() atomic_full_barrier ()
#endif
#ifndef atomic_write_barrier
-# define atomic_write_barrier() atomic_full_barrier()
+# define atomic_write_barrier() atomic_full_barrier ()
+#endif
+
+
+#ifndef atomic_forced_read
+# define atomic_forced_read(x) \
+ ({ __typeof (x) __x; __asm ("" : "=r" (__x) : "0" (x)); __x; })
+#endif
+
+/* This is equal to 1 iff the architecture supports 64b atomic operations. */
+#ifndef __HAVE_64B_ATOMICS
+#error Unable to determine if 64-bit atomics are present.
+#endif
+
+/* The following functions are a subset of the atomic operations provided by
+ C11. Usually, a function named atomic_OP_MO(args) is equivalent to C11's
+ atomic_OP_explicit(args, memory_order_MO); exceptions noted below. */
+
+/* Each arch can request to use compiler built-ins for C11 atomics. If it
+ does, all atomics will be based on these. */
+#if USE_ATOMIC_COMPILER_BUILTINS
+
+/* We require 32b atomic operations; some archs also support 64b atomic
+ operations. */
+void __atomic_link_error (void);
+# if __HAVE_64B_ATOMICS == 1
+# define __atomic_check_size(mem) \
+ if ((sizeof (*mem) != 4) && (sizeof (*mem) != 8)) \
+ __atomic_link_error ();
+# else
+# define __atomic_check_size(mem) \
+ if (sizeof (*mem) != 4) \
+ __atomic_link_error ();
+# endif
+/* We additionally provide 8b and 16b atomic loads and stores; we do not yet
+ need other atomic operations of such sizes, and restricting the support to
+ loads and stores makes this easier for archs that do not have native
+ support for atomic operations to less-than-word-sized data. */
+# if __HAVE_64B_ATOMICS == 1
+# define __atomic_check_size_ls(mem) \
+ if ((sizeof (*mem) != 1) && (sizeof (*mem) != 2) && (sizeof (*mem) != 4) \
+ && (sizeof (*mem) != 8)) \
+ __atomic_link_error ();
+# else
+# define __atomic_check_size_ls(mem) \
+ if ((sizeof (*mem) != 1) && (sizeof (*mem) != 2) && sizeof (*mem) != 4) \
+ __atomic_link_error ();
+# endif
+
+# define atomic_thread_fence_acquire() \
+ __atomic_thread_fence (__ATOMIC_ACQUIRE)
+# define atomic_thread_fence_release() \
+ __atomic_thread_fence (__ATOMIC_RELEASE)
+# define atomic_thread_fence_seq_cst() \
+ __atomic_thread_fence (__ATOMIC_SEQ_CST)
+
+# define atomic_load_relaxed(mem) \
+ ({ __atomic_check_size_ls((mem)); \
+ __atomic_load_n ((mem), __ATOMIC_RELAXED); })
+# define atomic_load_acquire(mem) \
+ ({ __atomic_check_size_ls((mem)); \
+ __atomic_load_n ((mem), __ATOMIC_ACQUIRE); })
+
+# define atomic_store_relaxed(mem, val) \
+ do { \
+ __atomic_check_size_ls((mem)); \
+ __atomic_store_n ((mem), (val), __ATOMIC_RELAXED); \
+ } while (0)
+# define atomic_store_release(mem, val) \
+ do { \
+ __atomic_check_size_ls((mem)); \
+ __atomic_store_n ((mem), (val), __ATOMIC_RELEASE); \
+ } while (0)
+
+/* On failure, this CAS has memory_order_relaxed semantics. */
+# define atomic_compare_exchange_weak_relaxed(mem, expected, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_compare_exchange_n ((mem), (expected), (desired), 1, \
+ __ATOMIC_RELAXED, __ATOMIC_RELAXED); })
+# define atomic_compare_exchange_weak_acquire(mem, expected, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_compare_exchange_n ((mem), (expected), (desired), 1, \
+ __ATOMIC_ACQUIRE, __ATOMIC_RELAXED); })
+# define atomic_compare_exchange_weak_release(mem, expected, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_compare_exchange_n ((mem), (expected), (desired), 1, \
+ __ATOMIC_RELEASE, __ATOMIC_RELAXED); })
+
+# define atomic_exchange_relaxed(mem, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_exchange_n ((mem), (desired), __ATOMIC_RELAXED); })
+# define atomic_exchange_acquire(mem, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_exchange_n ((mem), (desired), __ATOMIC_ACQUIRE); })
+# define atomic_exchange_release(mem, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_exchange_n ((mem), (desired), __ATOMIC_RELEASE); })
+
+# define atomic_fetch_add_relaxed(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_add ((mem), (operand), __ATOMIC_RELAXED); })
+# define atomic_fetch_add_acquire(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_add ((mem), (operand), __ATOMIC_ACQUIRE); })
+# define atomic_fetch_add_release(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_add ((mem), (operand), __ATOMIC_RELEASE); })
+# define atomic_fetch_add_acq_rel(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_add ((mem), (operand), __ATOMIC_ACQ_REL); })
+
+# define atomic_fetch_and_relaxed(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_and ((mem), (operand), __ATOMIC_RELAXED); })
+# define atomic_fetch_and_acquire(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_and ((mem), (operand), __ATOMIC_ACQUIRE); })
+# define atomic_fetch_and_release(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_and ((mem), (operand), __ATOMIC_RELEASE); })
+
+# define atomic_fetch_or_relaxed(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_or ((mem), (operand), __ATOMIC_RELAXED); })
+# define atomic_fetch_or_acquire(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_or ((mem), (operand), __ATOMIC_ACQUIRE); })
+# define atomic_fetch_or_release(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_or ((mem), (operand), __ATOMIC_RELEASE); })
+
+# define atomic_fetch_xor_release(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_xor ((mem), (operand), __ATOMIC_RELEASE); })
+
+#else /* !USE_ATOMIC_COMPILER_BUILTINS */
+
+/* By default, we assume that read, write, and full barriers are equivalent
+ to acquire, release, and seq_cst barriers. Archs for which this does not
+ hold have to provide custom definitions of the fences. */
+# ifndef atomic_thread_fence_acquire
+# define atomic_thread_fence_acquire() atomic_read_barrier ()
+# endif
+# ifndef atomic_thread_fence_release
+# define atomic_thread_fence_release() atomic_write_barrier ()
+# endif
+# ifndef atomic_thread_fence_seq_cst
+# define atomic_thread_fence_seq_cst() atomic_full_barrier ()
+# endif
+
+# ifndef atomic_load_relaxed
+# define atomic_load_relaxed(mem) \
+ ({ __typeof ((__typeof (*(mem))) *(mem)) __atg100_val; \
+ __asm ("" : "=r" (__atg100_val) : "0" (*(mem))); \
+ __atg100_val; })
+# endif
+# ifndef atomic_load_acquire
+# define atomic_load_acquire(mem) \
+ ({ __typeof (*(mem)) __atg101_val = atomic_load_relaxed (mem); \
+ atomic_thread_fence_acquire (); \
+ __atg101_val; })
+# endif
+
+# ifndef atomic_store_relaxed
+/* XXX Use inline asm here? */
+# define atomic_store_relaxed(mem, val) do { *(mem) = (val); } while (0)
+# endif
+# ifndef atomic_store_release
+# define atomic_store_release(mem, val) \
+ do { \
+ atomic_thread_fence_release (); \
+ atomic_store_relaxed ((mem), (val)); \
+ } while (0)
+# endif
+
+/* On failure, this CAS has memory_order_relaxed semantics. */
+/* XXX This potentially has one branch more than necessary, but archs
+ currently do not define a CAS that returns both the previous value and
+ the success flag. */
+# ifndef atomic_compare_exchange_weak_acquire
+# define atomic_compare_exchange_weak_acquire(mem, expected, desired) \
+ ({ typeof (*(expected)) __atg102_expected = *(expected); \
+ *(expected) = \
+ atomic_compare_and_exchange_val_acq ((mem), (desired), *(expected)); \
+ *(expected) == __atg102_expected; })
+# endif
+# ifndef atomic_compare_exchange_weak_relaxed
+/* XXX Fall back to CAS with acquire MO because archs do not define a weaker
+ CAS. */
+# define atomic_compare_exchange_weak_relaxed(mem, expected, desired) \
+ atomic_compare_exchange_weak_acquire ((mem), (expected), (desired))
+# endif
+# ifndef atomic_compare_exchange_weak_release
+# define atomic_compare_exchange_weak_release(mem, expected, desired) \
+ ({ typeof (*(expected)) __atg103_expected = *(expected); \
+ *(expected) = \
+ atomic_compare_and_exchange_val_rel ((mem), (desired), *(expected)); \
+ *(expected) == __atg103_expected; })
+# endif
+
+/* XXX Fall back to acquire MO because archs do not define a weaker
+ atomic_exchange. */
+# ifndef atomic_exchange_relaxed
+# define atomic_exchange_relaxed(mem, val) \
+ atomic_exchange_acq ((mem), (val))
+# endif
+# ifndef atomic_exchange_acquire
+# define atomic_exchange_acquire(mem, val) \
+ atomic_exchange_acq ((mem), (val))
+# endif
+# ifndef atomic_exchange_release
+# define atomic_exchange_release(mem, val) \
+ atomic_exchange_rel ((mem), (val))
+# endif
+
+# ifndef atomic_fetch_add_acquire
+# define atomic_fetch_add_acquire(mem, operand) \
+ atomic_exchange_and_add_acq ((mem), (operand))
+# endif
+# ifndef atomic_fetch_add_relaxed
+/* XXX Fall back to acquire MO because the MO semantics of
+ atomic_exchange_and_add are not documented; the generic version falls back
+ to atomic_exchange_and_add_acq if atomic_exchange_and_add is not defined,
+ and vice versa. */
+# define atomic_fetch_add_relaxed(mem, operand) \
+ atomic_fetch_add_acquire ((mem), (operand))
+# endif
+# ifndef atomic_fetch_add_release
+# define atomic_fetch_add_release(mem, operand) \
+ atomic_exchange_and_add_rel ((mem), (operand))
+# endif
+# ifndef atomic_fetch_add_acq_rel
+# define atomic_fetch_add_acq_rel(mem, operand) \
+ ({ atomic_thread_fence_release (); \
+ atomic_exchange_and_add_acq ((mem), (operand)); })
+# endif
+
+/* XXX Fall back to acquire MO because archs do not define a weaker
+ atomic_and_val. */
+# ifndef atomic_fetch_and_relaxed
+# define atomic_fetch_and_relaxed(mem, operand) \
+ atomic_fetch_and_acquire ((mem), (operand))
+# endif
+/* XXX The default for atomic_and_val has acquire semantics, but this is not
+ documented. */
+# ifndef atomic_fetch_and_acquire
+# define atomic_fetch_and_acquire(mem, operand) \
+ atomic_and_val ((mem), (operand))
+# endif
+# ifndef atomic_fetch_and_release
+/* XXX This unnecessarily has acquire MO. */
+# define atomic_fetch_and_release(mem, operand) \
+ ({ atomic_thread_fence_release (); \
+ atomic_and_val ((mem), (operand)); })
+# endif
+
+/* XXX The default for atomic_or_val has acquire semantics, but this is not
+ documented. */
+# ifndef atomic_fetch_or_acquire
+# define atomic_fetch_or_acquire(mem, operand) \
+ atomic_or_val ((mem), (operand))
+# endif
+/* XXX Fall back to acquire MO because archs do not define a weaker
+ atomic_or_val. */
+# ifndef atomic_fetch_or_relaxed
+# define atomic_fetch_or_relaxed(mem, operand) \
+ atomic_fetch_or_acquire ((mem), (operand))
+# endif
+/* XXX Contains an unnecessary acquire MO because archs do not define a weaker
+ atomic_or_val. */
+# ifndef atomic_fetch_or_release
+# define atomic_fetch_or_release(mem, operand) \
+ ({ atomic_thread_fence_release (); \
+ atomic_fetch_or_acquire ((mem), (operand)); })
+# endif
+
+# ifndef atomic_fetch_xor_release
+/* Failing the atomic_compare_exchange_weak_release reloads the value in
+ __atg104_expected, so we need only do the XOR again and retry. */
+# define atomic_fetch_xor_release(mem, operand) \
+ ({ __typeof (mem) __atg104_memp = (mem); \
+ __typeof (*(mem)) __atg104_expected = (*__atg104_memp); \
+ __typeof (*(mem)) __atg104_desired; \
+ __typeof (*(mem)) __atg104_op = (operand); \
+ \
+ do \
+ __atg104_desired = __atg104_expected ^ __atg104_op; \
+ while (__glibc_unlikely \
+ (atomic_compare_exchange_weak_release ( \
+ __atg104_memp, &__atg104_expected, __atg104_desired) \
+ == 0)); \
+ __atg104_expected; })
+#endif
+
+#endif /* !USE_ATOMIC_COMPILER_BUILTINS */
+
+/* This operation does not affect synchronization semantics but can be used
+ in the body of a spin loop to potentially improve its efficiency. */
+#ifndef atomic_spin_nop
+# define atomic_spin_nop() do { /* nothing */ } while (0)
+#endif
+
+/* ATOMIC_EXCHANGE_USES_CAS is non-zero if atomic_exchange operations
+ are implemented based on a CAS loop; otherwise, this is zero and we assume
+ that the atomic_exchange operations could provide better performance
+ than a CAS loop. */
+#ifndef ATOMIC_EXCHANGE_USES_CAS
+# error ATOMIC_EXCHANGE_USES_CAS has to be defined.
#endif
#endif /* atomic.h */
projects / thirdparty / glibc.git / blobdiff