[mirror_frr.git] / lib / frratomic.h

/*
 * Copyright (c) 2015-16  David Lamparter, for NetDEF, Inc.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _FRRATOMIC_H
#define _FRRATOMIC_H

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifndef FRR_AUTOCONF_ATOMIC
#error autoconf checks for atomic functions were not properly run
#endif

/* ISO C11 */
#ifdef HAVE_STDATOMIC_H
#include <stdatomic.h>

/* gcc 4.7 and newer */
#elif defined(HAVE___ATOMIC)

#define _Atomic volatile

#define memory_order_relaxed __ATOMIC_RELAXED
#define memory_order_consume __ATOMIC_CONSUME
#define memory_order_acquire __ATOMIC_ACQUIRE
#define memory_order_release __ATOMIC_RELEASE
#define memory_order_acq_rel __ATOMIC_ACQ_REL
#define memory_order_seq_cst __ATOMIC_SEQ_CST

#define atomic_load_explicit __atomic_load_n
#define atomic_store_explicit __atomic_store_n
#define atomic_exchange_explicit __atomic_exchange_n
#define atomic_fetch_add_explicit __atomic_fetch_add
#define atomic_fetch_sub_explicit __atomic_fetch_sub

#define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1,      \
					      mem2)                            \
	__atomic_compare_exchange_n(atom, expect, desire, 1, mem1, mem2)

/* gcc 4.1 and newer,
 * clang 3.3 (possibly older)
 *
 * __sync_swap isn't in gcc's documentation, but clang has it
 *
 * note __sync_synchronize()
 */
#elif defined(HAVE___SYNC)

#define _Atomic volatile

#define memory_order_relaxed 0
#define memory_order_consume 0
#define memory_order_acquire 0
#define memory_order_release 0
#define memory_order_acq_rel 0
#define memory_order_seq_cst 0

#define atomic_load_explicit(ptr, mem)                                         \
	({                                                                     \
		__sync_synchronize();                                          \
		typeof(*ptr) rval = __sync_fetch_and_add((ptr), 0);            \
		__sync_synchronize();                                          \
		rval;                                                          \
	})
#define atomic_store_explicit(ptr, val, mem)                                   \
	({                                                                     \
		__sync_synchronize();                                          \
		*(ptr) = (val);                                                \
		__sync_synchronize();                                          \
		(void)0;                                                       \
	})
#ifdef HAVE___SYNC_SWAP
#define atomic_exchange_explicit(ptr, val, mem)                                \
	({                                                                     \
		__sync_synchronize();                                          \
		typeof(*ptr) rval = __sync_swap((ptr, val), 0);                \
		__sync_synchronize();                                          \
		rval;                                                          \
	})
#else /* !HAVE___SYNC_SWAP */
#define atomic_exchange_explicit(ptr, val, mem)                                \
	({                                                                     \
		typeof(ptr) _ptr = (ptr);                                      \
		typeof(val) _val = (val);                                      \
		__sync_synchronize();                                          \
		typeof(*ptr) old1, old2 = __sync_fetch_and_add(_ptr, 0);       \
		do {                                                           \
			old1 = old2;                                           \
			old2 = __sync_val_compare_and_swap(_ptr, old1, _val);  \
		} while (old1 != old2);                                        \
		__sync_synchronize();                                          \
		old2;                                                          \
	})
#endif /* !HAVE___SYNC_SWAP */
#define atomic_fetch_add_explicit(ptr, val, mem)                               \
	({                                                                     \
		__sync_synchronize();                                          \
		typeof(*ptr) rval = __sync_fetch_and_add((ptr), (val));        \
		__sync_synchronize();                                          \
		rval;                                                          \
	})
#define atomic_fetch_sub_explicit(ptr, val, mem)                               \
	({                                                                     \
		__sync_synchronize();                                          \
		typeof(*ptr) rval = __sync_fetch_and_sub((ptr), (val));        \
		__sync_synchronize();                                          \
		rval;                                                          \
	})

#define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1,      \
					      mem2)                            \
	({                                                                     \
		typeof(atom) _atom = (atom);                                   \
		typeof(expect) _expect = (expect);                             \
		typeof(desire) _desire = (desire);                             \
		__sync_synchronize();                                          \
		typeof(*atom) rval =                                           \
			__sync_val_compare_and_swap(_atom, *_expect, _desire); \
		__sync_synchronize();                                          \
		bool ret = (rval == *_expect);                                 \
		*_expect = rval;                                               \
		ret;                                                           \
	})

#else /* !HAVE___ATOMIC && !HAVE_STDATOMIC_H */
#error no atomic functions...
#endif

#endif /* _FRRATOMIC_H */
Commit	Line	Data
899a4fd2 DL	1	/*
	2	* Copyright (c) 2015-16 David Lamparter, for NetDEF, Inc.
	3	*
	4	* Permission to use, copy, modify, and distribute this software for any
	5	* purpose with or without fee is hereby granted, provided that the above
	6	* copyright notice and this permission notice appear in all copies.
	7	*
	8	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	9	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	10	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	11	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	12	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	13	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	14	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	15	*/
	16
	17	#ifndef _FRRATOMIC_H
	18	#define _FRRATOMIC_H
	19
	20	#ifdef HAVE_CONFIG_H
	21	#include "config.h"
	22	#endif
	23
	24	#ifndef FRR_AUTOCONF_ATOMIC
	25	#error autoconf checks for atomic functions were not properly run
	26	#endif
	27
	28	/* ISO C11 */
	29	#ifdef HAVE_STDATOMIC_H
	30	#include <stdatomic.h>
	31
	32	/* gcc 4.7 and newer */
	33	#elif defined(HAVE___ATOMIC)
	34
	35	#define _Atomic volatile
	36
	37	#define memory_order_relaxed __ATOMIC_RELAXED
	38	#define memory_order_consume __ATOMIC_CONSUME
	39	#define memory_order_acquire __ATOMIC_ACQUIRE
	40	#define memory_order_release __ATOMIC_RELEASE
	41	#define memory_order_acq_rel __ATOMIC_ACQ_REL
	42	#define memory_order_seq_cst __ATOMIC_SEQ_CST
	43
	44	#define atomic_load_explicit __atomic_load_n
	45	#define atomic_store_explicit __atomic_store_n
	46	#define atomic_exchange_explicit __atomic_exchange_n
	47	#define atomic_fetch_add_explicit __atomic_fetch_add
	48	#define atomic_fetch_sub_explicit __atomic_fetch_sub
	49
d62a17ae	50	#define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1, \
d62a17ae	51	mem2) \
899a4fd2 DL	52	__atomic_compare_exchange_n(atom, expect, desire, 1, mem1, mem2)
	53
	54	/* gcc 4.1 and newer,
	55	* clang 3.3 (possibly older)
	56	*
	57	* __sync_swap isn't in gcc's documentation, but clang has it
	58	*
d62a17ae	59	* note __sync_synchronize()
899a4fd2 DL	60	*/
	61	#elif defined(HAVE___SYNC)
	62
	63	#define _Atomic volatile
	64
	65	#define memory_order_relaxed 0
	66	#define memory_order_consume 0
	67	#define memory_order_acquire 0
	68	#define memory_order_release 0
	69	#define memory_order_acq_rel 0
	70	#define memory_order_seq_cst 0
	71
d62a17ae	72	#define atomic_load_explicit(ptr, mem) \
	73	({ \
	74	__sync_synchronize(); \
	75	typeof(*ptr) rval = __sync_fetch_and_add((ptr), 0); \
	76	__sync_synchronize(); \
	77	rval; \
	78	})
	79	#define atomic_store_explicit(ptr, val, mem) \
	80	({ \
	81	__sync_synchronize(); \
	82	*(ptr) = (val); \
	83	__sync_synchronize(); \
	84	(void)0; \
	85	})
899a4fd2	86	#ifdef HAVE___SYNC_SWAP
d62a17ae	87	#define atomic_exchange_explicit(ptr, val, mem) \
	88	({ \
	89	__sync_synchronize(); \
	90	typeof(*ptr) rval = __sync_swap((ptr, val), 0); \
	91	__sync_synchronize(); \
	92	rval; \
	93	})
899a4fd2	94	#else /* !HAVE___SYNC_SWAP */
d62a17ae	95	#define atomic_exchange_explicit(ptr, val, mem) \
	96	({ \
	97	typeof(ptr) _ptr = (ptr); \
	98	typeof(val) _val = (val); \
	99	__sync_synchronize(); \
	100	typeof(*ptr) old1, old2 = __sync_fetch_and_add(_ptr, 0); \
	101	do { \
	102	old1 = old2; \
	103	old2 = __sync_val_compare_and_swap(_ptr, old1, _val); \
	104	} while (old1 != old2); \
	105	__sync_synchronize(); \
	106	old2; \
899a4fd2 DL	107	})
899a4fd2 DL	108	#endif /* !HAVE___SYNC_SWAP */
d62a17ae	109	#define atomic_fetch_add_explicit(ptr, val, mem) \
	110	({ \
	111	__sync_synchronize(); \
	112	typeof(*ptr) rval = __sync_fetch_and_add((ptr), (val)); \
	113	__sync_synchronize(); \
	114	rval; \
	115	})
	116	#define atomic_fetch_sub_explicit(ptr, val, mem) \
	117	({ \
	118	__sync_synchronize(); \
	119	typeof(*ptr) rval = __sync_fetch_and_sub((ptr), (val)); \
	120	__sync_synchronize(); \
	121	rval; \
	122	})
	123
	124	#define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1, \
	125	mem2) \
	126	({ \
	127	typeof(atom) _atom = (atom); \
	128	typeof(expect) _expect = (expect); \
	129	typeof(desire) _desire = (desire); \
	130	__sync_synchronize(); \
	131	typeof(*atom) rval = \
	132	__sync_val_compare_and_swap(_atom, *_expect, _desire); \
	133	__sync_synchronize(); \
	134	bool ret = (rval == *_expect); \
	135	*_expect = rval; \
	136	ret; \
	137	})
899a4fd2 DL	138
	139	#else /* !HAVE___ATOMIC && !HAVE_STDATOMIC_H */
	140	#error no atomic functions...
	141	#endif
	142
	143	#endif /* _FRRATOMIC_H */