[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
	50	#define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1, mem2) \
	51	__atomic_compare_exchange_n(atom, expect, desire, 1, mem1, mem2)
	52
	53	/* gcc 4.1 and newer,
	54	* clang 3.3 (possibly older)
	55	*
	56	* __sync_swap isn't in gcc's documentation, but clang has it
	57	*
	58	* note __sync_synchronize()
	59	*/
	60	#elif defined(HAVE___SYNC)
	61
	62	#define _Atomic volatile
	63
	64	#define memory_order_relaxed 0
65	#define memory_order_consume 0
66	#define memory_order_acquire 0
67	#define memory_order_release 0
68	#define memory_order_acq_rel 0
69	#define memory_order_seq_cst 0
70
71	#define atomic_load_explicit(ptr, mem) \
72	({ __sync_synchronize(); \
73	typeof(*ptr) rval = __sync_fetch_and_add((ptr), 0); \
74	__sync_synchronize(); rval; })
75	#define atomic_store_explicit(ptr, val, mem) \
76	({ __sync_synchronize(); \
77	*(ptr) = (val); \
78	__sync_synchronize(); (void)0; })
79	#ifdef HAVE___SYNC_SWAP
80	#define atomic_exchange_explicit(ptr, val, mem) \
81	({ __sync_synchronize(); \
82	typeof(*ptr) rval = __sync_swap((ptr, val), 0); \
83	__sync_synchronize(); rval; })
84	#else /* !HAVE___SYNC_SWAP */
85	#define atomic_exchange_explicit(ptr, val, mem) \
86	({ typeof(ptr) _ptr = (ptr); typeof(val) _val = (val); \
87	__sync_synchronize(); \
88	typeof(*ptr) old1, old2 = __sync_fetch_and_add(_ptr, 0); \
89	do { \
90	old1 = old2; \
91	old2 = __sync_val_compare_and_swap (_ptr, old1, _val); \
92	} while (old1 != old2); \
93	__sync_synchronize(); \
94	old2; \
95	})
96	#endif /* !HAVE___SYNC_SWAP */
97	#define atomic_fetch_add_explicit(ptr, val, mem) \
98	({ __sync_synchronize(); \
99	typeof(*ptr) rval = __sync_fetch_and_add((ptr), (val)); \
100	__sync_synchronize(); rval; })
101	#define atomic_fetch_sub_explicit(ptr, val, mem) \
102	({ __sync_synchronize(); \
103	typeof(*ptr) rval = __sync_fetch_and_sub((ptr), (val)); \
104	__sync_synchronize(); rval; })
105
106	#define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1, mem2) \
107	({ typeof(atom) _atom = (atom); typeof(expect) _expect = (expect); \
108	typeof(desire) _desire = (desire); \
109	__sync_synchronize(); \
110	typeof(atom) rval = __sync_val_compare_and_swap(_atom, _expect, _desire); \
111	__sync_synchronize(); \
112	bool ret = (rval == _expect); _expect = rval; ret; })
113
114	#else /* !HAVE___ATOMIC && !HAVE_STDATOMIC_H */
115	#error no atomic functions...
116	#endif
117
118	#endif /* _FRRATOMIC_H */