[mirror_frr.git] / lib / atomlist.h

/*
 * Copyright (c) 2016-2019  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 _FRR_ATOMLIST_H
#define _FRR_ATOMLIST_H

#include "typesafe.h"
#include "frratomic.h"

/* pointer with lock/deleted/invalid bit in lowest bit
 *
 * for atomlist/atomsort, "locked" means "this pointer can't be updated, the
 * item is being deleted".  it is permissible to assume the item will indeed
 * be deleted (as there are no replace/etc. ops in this).
 *
 * in general, lowest 2/3 bits on 32/64bit architectures are available for
 * uses like this; the only thing that will really break this is putting an
 * atomlist_item in a struct with "packed" attribute.  (it'll break
 * immediately and consistently.) -- don't do that.
 *
 * ATOMPTR_USER is currently unused (and available for atomic hash or skiplist
 * implementations.)
 */
typedef uintptr_t atomptr_t;
#define ATOMPTR_MASK (UINTPTR_MAX - 3)
#define ATOMPTR_LOCK (1)
#define ATOMPTR_USER (2)
#define ATOMPTR_NULL (0)

static inline atomptr_t atomptr_i(void *val)
{
	atomptr_t atomval = (atomptr_t)val;

	assert(!(atomval & ATOMPTR_LOCK));
	return atomval;
}
static inline void *atomptr_p(atomptr_t val)
{
	return (void *)(val & ATOMPTR_MASK);
}
static inline bool atomptr_l(atomptr_t val)
{
	return (bool)(val & ATOMPTR_LOCK);
}
static inline bool atomptr_u(atomptr_t val)
{
	return (bool)(val & ATOMPTR_USER);
}


/* the problem with, find(), find_gteq() and find_lt() on atomic lists is that
 * they're neither an "acquire" nor a "release" operation;  the element that
 * was found is still on the list and doesn't change ownership.  Therefore,
 * an atomic transition in ownership state can't be implemented.
 *
 * Contrast this with add() or pop(): both function calls atomically transfer
 * ownership of an item to or from the list, which makes them "acquire" /
 * "release" operations.
 *
 * What can be implemented atomically is a "find_pop()", i.e. try to locate an
 * item and atomically try to remove it if found.  It's not currently
 * implemented but can be added when needed.
 *
 * Either way - for find(), generally speaking, if you need to use find() on
 * a list then the whole thing probably isn't well-suited to atomic
 * implementation and you'll need to have extra locks around to make it work
 * correctly.
 */
#ifdef WNO_ATOMLIST_UNSAFE_FIND
# define atomic_find_warn
#else
# define atomic_find_warn __attribute__((_DEPRECATED( \
	"WARNING: find() on atomic lists cannot be atomic by principle; " \
	"check code to make sure usage pattern is OK and if it is, use " \
	"#define WNO_ATOMLIST_UNSAFE_FIND")))
#endif


/* single-linked list, unsorted/arbitrary.
 * can be used as queue with add_tail / pop
 *
 * all operations are lock-free, but not neccessarily wait-free.  this means
 * that there is no state where the system as a whole stops making process,
 * but it *is* possible that a *particular* thread is delayed by some time.
 *
 * the only way for this to happen is for other threads to continuously make
 * updates.  an inactive / blocked / deadlocked other thread cannot cause such
 * delays, and to cause such delays a thread must be heavily hitting the list -
 * it's a rather theoretical concern.
 */

/* don't use these structs directly */
struct atomlist_item {
	_Atomic atomptr_t next;
};
#define atomlist_itemp(val) ((struct atomlist_item *)atomptr_p(val))

struct atomlist_head {
	_Atomic atomptr_t first, last;
	_Atomic size_t count;
};

/* use as:
 *
 * PREDECL_ATOMLIST(namelist)
 * struct name {
 *   struct namelist_item nlitem;
 * }
 * DECLARE_ATOMLIST(namelist, struct name, nlitem)
 */
#define PREDECL_ATOMLIST(prefix)                                               \
struct prefix ## _head { struct atomlist_head ah; };                           \
struct prefix ## _item { struct atomlist_item ai; };

#define INIT_ATOMLIST(var) { }

#define DECLARE_ATOMLIST(prefix, type, field)                                  \
macro_inline void prefix ## _add_head(struct prefix##_head *h, type *item)     \
{	atomlist_add_head(&h->ah, &item->field.ai); }                          \
macro_inline void prefix ## _add_tail(struct prefix##_head *h, type *item)     \
{	atomlist_add_tail(&h->ah, &item->field.ai); }                          \
macro_inline void prefix ## _del_hint(struct prefix##_head *h, type *item,     \
		_Atomic atomptr_t *hint)                                       \
{	atomlist_del_hint(&h->ah, &item->field.ai, hint); }                    \
macro_inline void prefix ## _del(struct prefix##_head *h, type *item)          \
{	atomlist_del_hint(&h->ah, &item->field.ai, NULL); }                    \
macro_inline type *prefix ## _pop(struct prefix##_head *h)                     \
{	char *p = (char *)atomlist_pop(&h->ah);                                \
	return p ? (type *)(p - offsetof(type, field)) : NULL; }               \
macro_inline type *prefix ## _first(struct prefix##_head *h)                   \
{	char *p = atomptr_p(atomic_load_explicit(&h->ah.first,                 \
				memory_order_acquire));                        \
	return p ? (type *)(p - offsetof(type, field)) : NULL; }               \
macro_inline type *prefix ## _next(struct prefix##_head *h, type *item)        \
{	char *p = atomptr_p(atomic_load_explicit(&item->field.ai.next,         \
				memory_order_acquire));                        \
	return p ? (type *)(p - offsetof(type, field)) : NULL; }               \
macro_inline type *prefix ## _next_safe(struct prefix##_head *h, type *item)   \
{	return item ? prefix##_next(h, item) : NULL; }                         \
macro_inline size_t prefix ## _count(struct prefix##_head *h)                  \
{	return atomic_load_explicit(&h->ah.count, memory_order_relaxed); }     \
/* ... */

/* add_head:
 * - contention on ->first pointer
 * - return implies completion
 */
void atomlist_add_head(struct atomlist_head *h, struct atomlist_item *item);

/* add_tail:
 * - concurrent add_tail can cause wait but has progress guarantee
 * - return does NOT imply completion.  completion is only guaranteed after
 *   all other add_tail operations that started before this add_tail have
 *   completed as well.
 */
void atomlist_add_tail(struct atomlist_head *h, struct atomlist_item *item);

/* del/del_hint:
 *
 * OWNER MUST HOLD REFERENCE ON ITEM TO BE DELETED, ENSURING NO OTHER THREAD
 * WILL TRY TO DELETE THE SAME ITEM.  DELETING INCLUDES pop().
 *
 * as with all deletions, threads that started reading earlier may still hold
 * pointers to the deleted item.  completion is however guaranteed for all
 * reads starting later.
 */
void atomlist_del_hint(struct atomlist_head *h, struct atomlist_item *item,
		_Atomic atomptr_t *hint);

/* pop:
 *
 * as with all deletions, threads that started reading earlier may still hold
 * pointers to the deleted item.  completion is however guaranteed for all
 * reads starting later.
 */
struct atomlist_item *atomlist_pop(struct atomlist_head *h);


struct atomsort_item {
	_Atomic atomptr_t next;
};
#define atomsort_itemp(val) ((struct atomsort_item *)atomptr_p(val))

struct atomsort_head {
	_Atomic atomptr_t first;
	_Atomic size_t count;
};

#define _PREDECL_ATOMSORT(prefix)                                              \
struct prefix ## _head { struct atomsort_head ah; };                           \
struct prefix ## _item { struct atomsort_item ai; };

#define INIT_ATOMSORT_UNIQ(var)		{ }
#define INIT_ATOMSORT_NONUNIQ(var)	{ }

#define _DECLARE_ATOMSORT(prefix, type, field, cmpfn_nuq, cmpfn_uq)            \
macro_inline void prefix ## _init(struct prefix##_head *h)                     \
{                                                                              \
	memset(h, 0, sizeof(*h));                                              \
}                                                                              \
macro_inline void prefix ## _fini(struct prefix##_head *h)                     \
{                                                                              \
	assert(h->ah.count == 0);                                              \
	memset(h, 0, sizeof(*h));                                              \
}                                                                              \
macro_inline type *prefix ## _add(struct prefix##_head *h, type *item)         \
{                                                                              \
	struct atomsort_item *p;                                               \
	p = atomsort_add(&h->ah, &item->field.ai, cmpfn_uq);                   \
	return container_of_null(p, type, field.ai);                           \
}                                                                              \
macro_inline type *prefix ## _first(struct prefix##_head *h)                   \
{                                                                              \
	struct atomsort_item *p;                                               \
	p = atomptr_p(atomic_load_explicit(&h->ah.first,                       \
				memory_order_acquire));                        \
	return container_of_null(p, type, field.ai);                           \
}                                                                              \
macro_inline type *prefix ## _next(struct prefix##_head *h, type *item)        \
{                                                                              \
	struct atomsort_item *p;                                               \
	p = atomptr_p(atomic_load_explicit(&item->field.ai.next,               \
				memory_order_acquire));                        \
	return container_of_null(p, type, field.ai);                           \
}                                                                              \
macro_inline type *prefix ## _next_safe(struct prefix##_head *h, type *item)   \
{                                                                              \
	return item ? prefix##_next(h, item) : NULL;                           \
}                                                                              \
atomic_find_warn                                                               \
macro_inline type *prefix ## _find_gteq(struct prefix##_head *h,               \
		const type *item)                                              \
{                                                                              \
	type *p = prefix ## _first(h);                                         \
	while (p && cmpfn_nuq(&p->field.ai, &item->field.ai) < 0)              \
		p = prefix ## _next(h, p);                                     \
	return p;                                                              \
}                                                                              \
atomic_find_warn                                                               \
macro_inline type *prefix ## _find_lt(struct prefix##_head *h,                 \
		const type *item)                                              \
{                                                                              \
	type *p = prefix ## _first(h), *prev = NULL;                           \
	while (p && cmpfn_nuq(&p->field.ai, &item->field.ai) < 0)              \
		p = prefix ## _next(h, (prev = p));                            \
	return prev;                                                           \
}                                                                              \
macro_inline void prefix ## _del_hint(struct prefix##_head *h, type *item,     \
		_Atomic atomptr_t *hint)                                       \
{                                                                              \
	atomsort_del_hint(&h->ah, &item->field.ai, hint);                      \
}                                                                              \
macro_inline void prefix ## _del(struct prefix##_head *h, type *item)          \
{                                                                              \
	atomsort_del_hint(&h->ah, &item->field.ai, NULL);                      \
}                                                                              \
macro_inline size_t prefix ## _count(struct prefix##_head *h)                  \
{                                                                              \
	return atomic_load_explicit(&h->ah.count, memory_order_relaxed);       \
}                                                                              \
macro_inline type *prefix ## _pop(struct prefix##_head *h)                     \
{                                                                              \
	struct atomsort_item *p = atomsort_pop(&h->ah);                        \
	return p ? container_of(p, type, field.ai) : NULL;                     \
}                                                                              \
/* ... */

#define PREDECL_ATOMSORT_UNIQ(prefix)                                          \
	_PREDECL_ATOMSORT(prefix)
#define DECLARE_ATOMSORT_UNIQ(prefix, type, field, cmpfn)                      \
                                                                               \
macro_inline int prefix ## __cmp(const struct atomsort_item *a,                \
		const struct atomsort_item *b)                                 \
{                                                                              \
	return cmpfn(container_of(a, type, field.ai),                          \
			container_of(b, type, field.ai));                      \
}                                                                              \
                                                                               \
_DECLARE_ATOMSORT(prefix, type, field,                                         \
		prefix ## __cmp, prefix ## __cmp)                              \
                                                                               \
atomic_find_warn                                                               \
macro_inline type *prefix ## _find(struct prefix##_head *h, const type *item)  \
{                                                                              \
	type *p = prefix ## _first(h);                                         \
	int cmpval = 0;                                                        \
	while (p && (cmpval = cmpfn(p, item)) < 0)                             \
		p = prefix ## _next(h, p);                                     \
	if (!p || cmpval > 0)                                                  \
		return NULL;                                                   \
	return p;                                                              \
}                                                                              \
/* ... */

#define PREDECL_ATOMSORT_NONUNIQ(prefix)                                       \
	_PREDECL_ATOMSORT(prefix)
#define DECLARE_ATOMSORT_NONUNIQ(prefix, type, field, cmpfn)                   \
                                                                               \
macro_inline int prefix ## __cmp(const struct atomsort_item *a,                \
		const struct atomsort_item *b)                                 \
{                                                                              \
	return cmpfn(container_of(a, type, field.ai),                          \
			container_of(b, type, field.ai));                      \
}                                                                              \
macro_inline int prefix ## __cmp_uq(const struct atomsort_item *a,             \
		const struct atomsort_item *b)                                 \
{                                                                              \
	int cmpval = cmpfn(container_of(a, type, field.ai),                    \
			container_of(b, type, field.ai));                      \
	if (cmpval)                                                            \
		return cmpval;                                                 \
	if (a < b)                                                             \
		return -1;                                                     \
	if (a > b)                                                             \
		return 1;                                                      \
	return 0;                                                              \
}                                                                              \
                                                                               \
_DECLARE_ATOMSORT(prefix, type, field,                                         \
		prefix ## __cmp, prefix ## __cmp_uq)                           \
/* ... */

struct atomsort_item *atomsort_add(struct atomsort_head *h,
		struct atomsort_item *item, int (*cmpfn)(
			const struct atomsort_item *,
			const struct atomsort_item *));

void atomsort_del_hint(struct atomsort_head *h,
		struct atomsort_item *item, _Atomic atomptr_t *hint);

struct atomsort_item *atomsort_pop(struct atomsort_head *h);

#endif /* _FRR_ATOMLIST_H */
Commit	Line	Data
bcea0c0f DL	1	/*
	2	* Copyright (c) 2016-2019 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 _FRR_ATOMLIST_H
	18	#define _FRR_ATOMLIST_H
	19
	20	#include "typesafe.h"
	21	#include "frratomic.h"
	22
	23	/* pointer with lock/deleted/invalid bit in lowest bit
	24	*
	25	* for atomlist/atomsort, "locked" means "this pointer can't be updated, the
	26	* item is being deleted". it is permissible to assume the item will indeed
	27	* be deleted (as there are no replace/etc. ops in this).
	28	*
	29	* in general, lowest 2/3 bits on 32/64bit architectures are available for
	30	* uses like this; the only thing that will really break this is putting an
	31	* atomlist_item in a struct with "packed" attribute. (it'll break
	32	* immediately and consistently.) -- don't do that.
	33	*
	34	* ATOMPTR_USER is currently unused (and available for atomic hash or skiplist
	35	* implementations.)
	36	*/
	37	typedef uintptr_t atomptr_t;
	38	#define ATOMPTR_MASK (UINTPTR_MAX - 3)
	39	#define ATOMPTR_LOCK (1)
	40	#define ATOMPTR_USER (2)
	41	#define ATOMPTR_NULL (0)
	42
	43	static inline atomptr_t atomptr_i(void *val)
	44	{
	45	atomptr_t atomval = (atomptr_t)val;
	46
	47	assert(!(atomval & ATOMPTR_LOCK));
	48	return atomval;
	49	}
	50	static inline void *atomptr_p(atomptr_t val)
	51	{
	52	return (void *)(val & ATOMPTR_MASK);
	53	}
	54	static inline bool atomptr_l(atomptr_t val)
	55	{
	56	return (bool)(val & ATOMPTR_LOCK);
	57	}
	58	static inline bool atomptr_u(atomptr_t val)
	59	{
	60	return (bool)(val & ATOMPTR_USER);
	61	}
	62
	63
	64	/* the problem with, find(), find_gteq() and find_lt() on atomic lists is that
65	* they're neither an "acquire" nor a "release" operation; the element that
66	* was found is still on the list and doesn't change ownership. Therefore,
67	* an atomic transition in ownership state can't be implemented.
68	*
69	* Contrast this with add() or pop(): both function calls atomically transfer
70	* ownership of an item to or from the list, which makes them "acquire" /
71	* "release" operations.
72	*
73	* What can be implemented atomically is a "find_pop()", i.e. try to locate an
74	* item and atomically try to remove it if found. It's not currently
75	* implemented but can be added when needed.
76	*
77	* Either way - for find(), generally speaking, if you need to use find() on
78	* a list then the whole thing probably isn't well-suited to atomic
79	* implementation and you'll need to have extra locks around to make it work
80	* correctly.
81	*/
82	#ifdef WNO_ATOMLIST_UNSAFE_FIND
83	# define atomic_find_warn
84	#else
85	# define atomic_find_warn __attribute__((_DEPRECATED( \
86	"WARNING: find() on atomic lists cannot be atomic by principle; " \
87	"check code to make sure usage pattern is OK and if it is, use " \
88	"#define WNO_ATOMLIST_UNSAFE_FIND")))
89	#endif
90
91
92	/* single-linked list, unsorted/arbitrary.
93	* can be used as queue with add_tail / pop
94	*
95	* all operations are lock-free, but not neccessarily wait-free. this means
96	* that there is no state where the system as a whole stops making process,
97	* but it is possible that a particular thread is delayed by some time.
98	*
99	* the only way for this to happen is for other threads to continuously make
100	* updates. an inactive / blocked / deadlocked other thread cannot cause such
101	* delays, and to cause such delays a thread must be heavily hitting the list -
102	* it's a rather theoretical concern.
103	*/
104
105	/* don't use these structs directly */
106	struct atomlist_item {
107	_Atomic atomptr_t next;
108	};
109	#define atomlist_itemp(val) ((struct atomlist_item *)atomptr_p(val))
110
111	struct atomlist_head {
112	_Atomic atomptr_t first, last;
113	_Atomic size_t count;
114	};
115
116	/* use as:
117	*
118	* PREDECL_ATOMLIST(namelist)
119	* struct name {
120	* struct namelist_item nlitem;
121	* }
122	* DECLARE_ATOMLIST(namelist, struct name, nlitem)
123	*/
124	#define PREDECL_ATOMLIST(prefix) \
125	struct prefix ## _head { struct atomlist_head ah; }; \
126	struct prefix ## _item { struct atomlist_item ai; };
127
128	#define INIT_ATOMLIST(var) { }
129
130	#define DECLARE_ATOMLIST(prefix, type, field) \
131	macro_inline void prefix ## _add_head(struct prefix##_head h, type item) \
132	{ atomlist_add_head(&h->ah, &item->field.ai); } \
133	macro_inline void prefix ## _add_tail(struct prefix##_head h, type item) \
134	{ atomlist_add_tail(&h->ah, &item->field.ai); } \
135	macro_inline void prefix ## _del_hint(struct prefix##_head h, type item, \
136	_Atomic atomptr_t *hint) \
137	{ atomlist_del_hint(&h->ah, &item->field.ai, hint); } \
138	macro_inline void prefix ## _del(struct prefix##_head h, type item) \
139	{ atomlist_del_hint(&h->ah, &item->field.ai, NULL); } \
140	macro_inline type prefix ## _pop(struct prefix##_head h) \
141	{ char p = (char )atomlist_pop(&h->ah); \
142	return p ? (type *)(p - offsetof(type, field)) : NULL; } \
143	macro_inline type prefix ## _first(struct prefix##_head h) \
144	{ char *p = atomptr_p(atomic_load_explicit(&h->ah.first, \
145	memory_order_acquire)); \
146	return p ? (type *)(p - offsetof(type, field)) : NULL; } \
147	macro_inline type prefix ## _next(struct prefix##_head h, type *item) \
148	{ char *p = atomptr_p(atomic_load_explicit(&item->field.ai.next, \
149	memory_order_acquire)); \
150	return p ? (type *)(p - offsetof(type, field)) : NULL; } \
151	macro_inline type prefix ## _next_safe(struct prefix##_head h, type *item) \
152	{ return item ? prefix##_next(h, item) : NULL; } \
153	macro_inline size_t prefix ## _count(struct prefix##_head *h) \
154	{ return atomic_load_explicit(&h->ah.count, memory_order_relaxed); } \
155	/* ... */
156
157	/* add_head:
158	* - contention on ->first pointer
159	* - return implies completion
160	*/
161	void atomlist_add_head(struct atomlist_head h, struct atomlist_item item);
162
163	/* add_tail:
164	* - concurrent add_tail can cause wait but has progress guarantee
165	* - return does NOT imply completion. completion is only guaranteed after
166	* all other add_tail operations that started before this add_tail have
167	* completed as well.
168	*/
169	void atomlist_add_tail(struct atomlist_head h, struct atomlist_item item);
170
171	/* del/del_hint:
172	*
173	* OWNER MUST HOLD REFERENCE ON ITEM TO BE DELETED, ENSURING NO OTHER THREAD
174	* WILL TRY TO DELETE THE SAME ITEM. DELETING INCLUDES pop().
175	*
176	* as with all deletions, threads that started reading earlier may still hold
177	* pointers to the deleted item. completion is however guaranteed for all
178	* reads starting later.
179	*/
180	void atomlist_del_hint(struct atomlist_head h, struct atomlist_item item,
181	_Atomic atomptr_t *hint);
182
183	/* pop:
184	*
185	* as with all deletions, threads that started reading earlier may still hold
186	* pointers to the deleted item. completion is however guaranteed for all
187	* reads starting later.
188	*/
189	struct atomlist_item atomlist_pop(struct atomlist_head h);
190
191
192
193	struct atomsort_item {
194	_Atomic atomptr_t next;
195	};
196	#define atomsort_itemp(val) ((struct atomsort_item *)atomptr_p(val))
197
198	struct atomsort_head {
199	_Atomic atomptr_t first;
200	_Atomic size_t count;
201	};
202
203	#define _PREDECL_ATOMSORT(prefix) \
204	struct prefix ## _head { struct atomsort_head ah; }; \
205	struct prefix ## _item { struct atomsort_item ai; };
206
207	#define INIT_ATOMSORT_UNIQ(var) { }
208	#define INIT_ATOMSORT_NONUNIQ(var) { }
209
210	#define _DECLARE_ATOMSORT(prefix, type, field, cmpfn_nuq, cmpfn_uq) \
211	macro_inline void prefix ## _init(struct prefix##_head *h) \
212	{ \
213	memset(h, 0, sizeof(*h)); \
214	} \
215	macro_inline void prefix ## _fini(struct prefix##_head *h) \
216	{ \
217	assert(h->ah.count == 0); \
218	memset(h, 0, sizeof(*h)); \
219	} \
220	macro_inline type prefix ## _add(struct prefix##_head h, type *item) \
221	{ \
222	struct atomsort_item *p; \
223	p = atomsort_add(&h->ah, &item->field.ai, cmpfn_uq); \
224	return container_of_null(p, type, field.ai); \
225	} \
226	macro_inline type prefix ## _first(struct prefix##_head h) \
227	{ \
228	struct atomsort_item *p; \
229	p = atomptr_p(atomic_load_explicit(&h->ah.first, \
230	memory_order_acquire)); \
231	return container_of_null(p, type, field.ai); \
232	} \
233	macro_inline type prefix ## _next(struct prefix##_head h, type *item) \
234	{ \
235	struct atomsort_item *p; \
236	p = atomptr_p(atomic_load_explicit(&item->field.ai.next, \
237	memory_order_acquire)); \
238	return container_of_null(p, type, field.ai); \
239	} \
240	macro_inline type prefix ## _next_safe(struct prefix##_head h, type *item) \
241	{ \
242	return item ? prefix##_next(h, item) : NULL; \
243	} \
244	atomic_find_warn \
245	macro_inline type prefix ## _find_gteq(struct prefix##_head h, \
246	const type *item) \
247	{ \
248	type *p = prefix ## _first(h); \
249	while (p && cmpfn_nuq(&p->field.ai, &item->field.ai) < 0) \
250	p = prefix ## _next(h, p); \
251	return p; \
252	} \
253	atomic_find_warn \
254	macro_inline type prefix ## _find_lt(struct prefix##_head h, \
255	const type *item) \
256	{ \
257	type p = prefix ## _first(h), prev = NULL; \
258	while (p && cmpfn_nuq(&p->field.ai, &item->field.ai) < 0) \
259	p = prefix ## _next(h, (prev = p)); \
260	return prev; \
261	} \
262	macro_inline void prefix ## _del_hint(struct prefix##_head h, type item, \
263	_Atomic atomptr_t *hint) \
264	{ \
265	atomsort_del_hint(&h->ah, &item->field.ai, hint); \
266	} \
267	macro_inline void prefix ## _del(struct prefix##_head h, type item) \
268	{ \
269	atomsort_del_hint(&h->ah, &item->field.ai, NULL); \
270	} \
271	macro_inline size_t prefix ## _count(struct prefix##_head *h) \
272	{ \
273	return atomic_load_explicit(&h->ah.count, memory_order_relaxed); \
274	} \
275	macro_inline type prefix ## _pop(struct prefix##_head h) \
276	{ \
277	struct atomsort_item *p = atomsort_pop(&h->ah); \
278	return p ? container_of(p, type, field.ai) : NULL; \
279	} \
280	/* ... */
281
282	#define PREDECL_ATOMSORT_UNIQ(prefix) \
283	_PREDECL_ATOMSORT(prefix)
284	#define DECLARE_ATOMSORT_UNIQ(prefix, type, field, cmpfn) \
285	\
286	macro_inline int prefix ## __cmp(const struct atomsort_item *a, \
287	const struct atomsort_item *b) \
288	{ \
289	return cmpfn(container_of(a, type, field.ai), \
290	container_of(b, type, field.ai)); \
291	} \
292	\
293	_DECLARE_ATOMSORT(prefix, type, field, \
294	prefix ## __cmp, prefix ## __cmp) \
295	\
296	atomic_find_warn \
297	macro_inline type prefix ## _find(struct prefix##_head h, const type *item) \
298	{ \
299	type *p = prefix ## _first(h); \
300	int cmpval = 0; \
301	while (p && (cmpval = cmpfn(p, item)) < 0) \
302	p = prefix ## _next(h, p); \
303	if (!p \|\| cmpval > 0) \
304	return NULL; \
305	return p; \
306	} \
307	/* ... */
308
309	#define PREDECL_ATOMSORT_NONUNIQ(prefix) \
310	_PREDECL_ATOMSORT(prefix)
311	#define DECLARE_ATOMSORT_NONUNIQ(prefix, type, field, cmpfn) \
312	\
313	macro_inline int prefix ## __cmp(const struct atomsort_item *a, \
314	const struct atomsort_item *b) \
315	{ \
316	return cmpfn(container_of(a, type, field.ai), \
317	container_of(b, type, field.ai)); \
318	} \
319	macro_inline int prefix ## __cmp_uq(const struct atomsort_item *a, \
320	const struct atomsort_item *b) \
321	{ \
322	int cmpval = cmpfn(container_of(a, type, field.ai), \
323	container_of(b, type, field.ai)); \
324	if (cmpval) \
325	return cmpval; \
326	if (a < b) \
327	return -1; \
328	if (a > b) \
329	return 1; \
330	return 0; \
331	} \
332	\
333	_DECLARE_ATOMSORT(prefix, type, field, \
334	prefix ## __cmp, prefix ## __cmp_uq) \
335	/* ... */
336
337	struct atomsort_item atomsort_add(struct atomsort_head h,
338	struct atomsort_item item, int (cmpfn)(
339	const struct atomsort_item *,
340	const struct atomsort_item *));
341
342	void atomsort_del_hint(struct atomsort_head *h,
343	struct atomsort_item item, _Atomic atomptr_t hint);
344
345	struct atomsort_item atomsort_pop(struct atomsort_head h);
346
347	#endif /* _FRR_ATOMLIST_H */