[mirror_frr.git] / lib / atomlist.h

// SPDX-License-Identifier: ISC
/*
 * Copyright (c) 2016-2019  David Lamparter, for NetDEF, Inc.
 */

#ifndef _FRR_ATOMLIST_H
#define _FRR_ATOMLIST_H

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

#ifdef __cplusplus
extern "C" {
#endif

/* 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.)
 */

/* atomic_atomptr_t may look a bit odd, it's for the sake of C++ compat */
typedef uintptr_t		atomptr_t;
typedef atomic_uintptr_t	atomic_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 necessarily 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_uintptr_t next;
};
#define atomlist_itemp(val) ((struct atomlist_item *)atomptr_p(val))

struct atomlist_head {
	atomic_uintptr_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; };                           \
MACRO_REQUIRE_SEMICOLON() /* end */

#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 type *prefix ## _del(struct prefix##_head *h, type *item)         \
{	atomlist_del_hint(&h->ah, &item->field.ai, NULL);                      \
	/* TODO: Return NULL if not found */                                   \
	return item; }                                                         \
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); }     \
macro_inline void prefix ## _init(struct prefix##_head *h)                     \
{                                                                              \
	memset(h, 0, sizeof(*h));                                              \
}                                                                              \
macro_inline void prefix ## _fini(struct prefix##_head *h)                     \
{                                                                              \
	assert(prefix ## _count(h) == 0);                                      \
	memset(h, 0, sizeof(*h));                                              \
}                                                                              \
MACRO_REQUIRE_SEMICOLON() /* end */

/* 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; };                           \
MACRO_REQUIRE_SEMICOLON() /* end */

#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 type *prefix ## _del(struct prefix##_head *h, type *item)         \
{                                                                              \
	atomsort_del_hint(&h->ah, &item->field.ai, NULL);                      \
	/* TODO: Return NULL if not found */                                   \
	return item;                                                           \
}                                                                              \
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;                     \
}                                                                              \
MACRO_REQUIRE_SEMICOLON() /* end */

#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;                                                              \
}                                                                              \
MACRO_REQUIRE_SEMICOLON() /* end */

#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);                          \
MACRO_REQUIRE_SEMICOLON() /* end */

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);

#ifdef __cplusplus
}
#endif

#endif /* _FRR_ATOMLIST_H */
Commit	Line	Data
acddc0ed	1	// SPDX-License-Identifier: ISC
bcea0c0f DL	2	/*
bcea0c0f DL	3	* Copyright (c) 2016-2019 David Lamparter, for NetDEF, Inc.
bcea0c0f DL	4	*/
	5
	6	#ifndef _FRR_ATOMLIST_H
	7	#define _FRR_ATOMLIST_H
	8
	9	#include "typesafe.h"
	10	#include "frratomic.h"
	11
17e38209 RW	12	#ifdef __cplusplus
	13	extern "C" {
	14	#endif
	15
bcea0c0f DL	16	/* pointer with lock/deleted/invalid bit in lowest bit
	17	*
	18	* for atomlist/atomsort, "locked" means "this pointer can't be updated, the
	19	* item is being deleted". it is permissible to assume the item will indeed
	20	* be deleted (as there are no replace/etc. ops in this).
	21	*
	22	* in general, lowest 2/3 bits on 32/64bit architectures are available for
	23	* uses like this; the only thing that will really break this is putting an
	24	* atomlist_item in a struct with "packed" attribute. (it'll break
	25	* immediately and consistently.) -- don't do that.
	26	*
	27	* ATOMPTR_USER is currently unused (and available for atomic hash or skiplist
	28	* implementations.)
	29	*/
5d6299d7 DL	30
	31	/* atomic_atomptr_t may look a bit odd, it's for the sake of C++ compat */
	32	typedef uintptr_t atomptr_t;
	33	typedef atomic_uintptr_t atomic_atomptr_t;
	34
bcea0c0f DL	35	#define ATOMPTR_MASK (UINTPTR_MAX - 3)
	36	#define ATOMPTR_LOCK (1)
	37	#define ATOMPTR_USER (2)
	38	#define ATOMPTR_NULL (0)
	39
	40	static inline atomptr_t atomptr_i(void *val)
	41	{
	42	atomptr_t atomval = (atomptr_t)val;
	43
	44	assert(!(atomval & ATOMPTR_LOCK));
	45	return atomval;
	46	}
	47	static inline void *atomptr_p(atomptr_t val)
	48	{
	49	return (void *)(val & ATOMPTR_MASK);
	50	}
	51	static inline bool atomptr_l(atomptr_t val)
	52	{
	53	return (bool)(val & ATOMPTR_LOCK);
	54	}
	55	static inline bool atomptr_u(atomptr_t val)
	56	{
	57	return (bool)(val & ATOMPTR_USER);
	58	}
	59
	60
	61	/* the problem with, find(), find_gteq() and find_lt() on atomic lists is that
	62	* they're neither an "acquire" nor a "release" operation; the element that
	63	* was found is still on the list and doesn't change ownership. Therefore,
	64	* an atomic transition in ownership state can't be implemented.
	65	*
	66	* Contrast this with add() or pop(): both function calls atomically transfer
	67	* ownership of an item to or from the list, which makes them "acquire" /
	68	* "release" operations.
	69	*
	70	* What can be implemented atomically is a "find_pop()", i.e. try to locate an
	71	* item and atomically try to remove it if found. It's not currently
	72	* implemented but can be added when needed.
	73	*
	74	* Either way - for find(), generally speaking, if you need to use find() on
	75	* a list then the whole thing probably isn't well-suited to atomic
	76	* implementation and you'll need to have extra locks around to make it work
	77	* correctly.
	78	*/
	79	#ifdef WNO_ATOMLIST_UNSAFE_FIND
	80	# define atomic_find_warn
	81	#else
	82	# define atomic_find_warn __attribute__((_DEPRECATED( \
	83	"WARNING: find() on atomic lists cannot be atomic by principle; " \
	84	"check code to make sure usage pattern is OK and if it is, use " \
	85	"#define WNO_ATOMLIST_UNSAFE_FIND")))
	86	#endif
	87
	88
	89	/* single-linked list, unsorted/arbitrary.
	90	* can be used as queue with add_tail / pop
	91	*
214d8a60	92	* all operations are lock-free, but not necessarily wait-free. this means
bcea0c0f DL	93	* that there is no state where the system as a whole stops making process,
	94	* but it is possible that a particular thread is delayed by some time.
	95	*
	96	* the only way for this to happen is for other threads to continuously make
	97	* updates. an inactive / blocked / deadlocked other thread cannot cause such
	98	* delays, and to cause such delays a thread must be heavily hitting the list -
	99	* it's a rather theoretical concern.
	100	*/
	101
	102	/* don't use these structs directly */
	103	struct atomlist_item {
5d6299d7	104	atomic_uintptr_t next;
bcea0c0f DL	105	};
	106	#define atomlist_itemp(val) ((struct atomlist_item *)atomptr_p(val))
	107
	108	struct atomlist_head {
5d6299d7 DL	109	atomic_uintptr_t first, last;
5d6299d7 DL	110	atomic_size_t count;
bcea0c0f DL	111	};
	112
	113	/* use as:
	114	*
960b9a53	115	* PREDECL_ATOMLIST(namelist);
bcea0c0f DL	116	* struct name {
	117	* struct namelist_item nlitem;
	118	* }
960b9a53	119	* DECLARE_ATOMLIST(namelist, struct name, nlitem);
bcea0c0f DL	120	*/
	121	#define PREDECL_ATOMLIST(prefix) \
	122	struct prefix ## _head { struct atomlist_head ah; }; \
960b9a53 DL	123	struct prefix ## _item { struct atomlist_item ai; }; \
960b9a53 DL	124	MACRO_REQUIRE_SEMICOLON() /* end */
bcea0c0f DL	125
	126	#define INIT_ATOMLIST(var) { }
	127
	128	#define DECLARE_ATOMLIST(prefix, type, field) \
	129	macro_inline void prefix ## _add_head(struct prefix##_head h, type item) \
	130	{ atomlist_add_head(&h->ah, &item->field.ai); } \
	131	macro_inline void prefix ## _add_tail(struct prefix##_head h, type item) \
	132	{ atomlist_add_tail(&h->ah, &item->field.ai); } \
	133	macro_inline void prefix ## _del_hint(struct prefix##_head h, type item, \
5d6299d7	134	atomic_atomptr_t *hint) \
bcea0c0f	135	{ atomlist_del_hint(&h->ah, &item->field.ai, hint); } \
da098d78 SW	136	macro_inline type prefix ## _del(struct prefix##_head h, type *item) \
	137	{ atomlist_del_hint(&h->ah, &item->field.ai, NULL); \
	138	/* TODO: Return NULL if not found */ \
	139	return item; } \
bcea0c0f DL	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); } \
9680a2af DL	155	macro_inline void prefix ## _init(struct prefix##_head *h) \
	156	{ \
	157	memset(h, 0, sizeof(*h)); \
	158	} \
	159	macro_inline void prefix ## _fini(struct prefix##_head *h) \
	160	{ \
	161	assert(prefix ## _count(h) == 0); \
	162	memset(h, 0, sizeof(*h)); \
	163	} \
960b9a53	164	MACRO_REQUIRE_SEMICOLON() /* end */
bcea0c0f DL	165
	166	/* add_head:
	167	* - contention on ->first pointer
	168	* - return implies completion
	169	*/
	170	void atomlist_add_head(struct atomlist_head h, struct atomlist_item item);
	171
	172	/* add_tail:
	173	* - concurrent add_tail can cause wait but has progress guarantee
	174	* - return does NOT imply completion. completion is only guaranteed after
	175	* all other add_tail operations that started before this add_tail have
	176	* completed as well.
	177	*/
	178	void atomlist_add_tail(struct atomlist_head h, struct atomlist_item item);
	179
	180	/* del/del_hint:
	181	*
	182	* OWNER MUST HOLD REFERENCE ON ITEM TO BE DELETED, ENSURING NO OTHER THREAD
	183	* WILL TRY TO DELETE THE SAME ITEM. DELETING INCLUDES 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	void atomlist_del_hint(struct atomlist_head h, struct atomlist_item item,
5d6299d7	190	atomic_atomptr_t *hint);
bcea0c0f DL	191
	192	/* pop:
	193	*
	194	* as with all deletions, threads that started reading earlier may still hold
	195	* pointers to the deleted item. completion is however guaranteed for all
	196	* reads starting later.
	197	*/
	198	struct atomlist_item atomlist_pop(struct atomlist_head h);
	199
	200
	201
	202	struct atomsort_item {
5d6299d7	203	atomic_atomptr_t next;
bcea0c0f DL	204	};
	205	#define atomsort_itemp(val) ((struct atomsort_item *)atomptr_p(val))
	206
	207	struct atomsort_head {
5d6299d7 DL	208	atomic_atomptr_t first;
5d6299d7 DL	209	atomic_size_t count;
bcea0c0f DL	210	};
	211
	212	#define _PREDECL_ATOMSORT(prefix) \
	213	struct prefix ## _head { struct atomsort_head ah; }; \
960b9a53 DL	214	struct prefix ## _item { struct atomsort_item ai; }; \
960b9a53 DL	215	MACRO_REQUIRE_SEMICOLON() /* end */
bcea0c0f DL	216
	217	#define INIT_ATOMSORT_UNIQ(var) { }
	218	#define INIT_ATOMSORT_NONUNIQ(var) { }
	219
	220	#define _DECLARE_ATOMSORT(prefix, type, field, cmpfn_nuq, cmpfn_uq) \
	221	macro_inline void prefix ## _init(struct prefix##_head *h) \
	222	{ \
	223	memset(h, 0, sizeof(*h)); \
	224	} \
	225	macro_inline void prefix ## _fini(struct prefix##_head *h) \
	226	{ \
	227	assert(h->ah.count == 0); \
	228	memset(h, 0, sizeof(*h)); \
	229	} \
	230	macro_inline type prefix ## _add(struct prefix##_head h, type *item) \
	231	{ \
	232	struct atomsort_item *p; \
	233	p = atomsort_add(&h->ah, &item->field.ai, cmpfn_uq); \
	234	return container_of_null(p, type, field.ai); \
	235	} \
	236	macro_inline type prefix ## _first(struct prefix##_head h) \
	237	{ \
	238	struct atomsort_item *p; \
	239	p = atomptr_p(atomic_load_explicit(&h->ah.first, \
	240	memory_order_acquire)); \
	241	return container_of_null(p, type, field.ai); \
	242	} \
	243	macro_inline type prefix ## _next(struct prefix##_head h, type *item) \
	244	{ \
	245	struct atomsort_item *p; \
	246	p = atomptr_p(atomic_load_explicit(&item->field.ai.next, \
	247	memory_order_acquire)); \
	248	return container_of_null(p, type, field.ai); \
	249	} \
	250	macro_inline type prefix ## _next_safe(struct prefix##_head h, type *item) \
	251	{ \
	252	return item ? prefix##_next(h, item) : NULL; \
	253	} \
	254	atomic_find_warn \
	255	macro_inline type prefix ## _find_gteq(struct prefix##_head h, \
	256	const type *item) \
	257	{ \
	258	type *p = prefix ## _first(h); \
	259	while (p && cmpfn_nuq(&p->field.ai, &item->field.ai) < 0) \
	260	p = prefix ## _next(h, p); \
	261	return p; \
	262	} \
	263	atomic_find_warn \
	264	macro_inline type prefix ## _find_lt(struct prefix##_head h, \
	265	const type *item) \
	266	{ \
	267	type p = prefix ## _first(h), prev = NULL; \
	268	while (p && cmpfn_nuq(&p->field.ai, &item->field.ai) < 0) \
	269	p = prefix ## _next(h, (prev = p)); \
	270	return prev; \
	271	} \
	272	macro_inline void prefix ## _del_hint(struct prefix##_head h, type item, \
5d6299d7	273	atomic_atomptr_t *hint) \
bcea0c0f DL	274	{ \
	275	atomsort_del_hint(&h->ah, &item->field.ai, hint); \
	276	} \
da098d78	277	macro_inline type prefix ## _del(struct prefix##_head h, type *item) \
bcea0c0f DL	278	{ \
bcea0c0f DL	279	atomsort_del_hint(&h->ah, &item->field.ai, NULL); \
da098d78 SW	280	/* TODO: Return NULL if not found */ \
da098d78 SW	281	return item; \
bcea0c0f DL	282	} \
	283	macro_inline size_t prefix ## _count(struct prefix##_head *h) \
	284	{ \
	285	return atomic_load_explicit(&h->ah.count, memory_order_relaxed); \
	286	} \
	287	macro_inline type prefix ## _pop(struct prefix##_head h) \
	288	{ \
	289	struct atomsort_item *p = atomsort_pop(&h->ah); \
	290	return p ? container_of(p, type, field.ai) : NULL; \
	291	} \
960b9a53	292	MACRO_REQUIRE_SEMICOLON() /* end */
bcea0c0f DL	293
	294	#define PREDECL_ATOMSORT_UNIQ(prefix) \
	295	_PREDECL_ATOMSORT(prefix)
	296	#define DECLARE_ATOMSORT_UNIQ(prefix, type, field, cmpfn) \
	297	\
	298	macro_inline int prefix ## __cmp(const struct atomsort_item *a, \
	299	const struct atomsort_item *b) \
	300	{ \
	301	return cmpfn(container_of(a, type, field.ai), \
	302	container_of(b, type, field.ai)); \
	303	} \
	304	\
	305	_DECLARE_ATOMSORT(prefix, type, field, \
960b9a53	306	prefix ## __cmp, prefix ## __cmp); \
bcea0c0f DL	307	\
	308	atomic_find_warn \
	309	macro_inline type prefix ## _find(struct prefix##_head h, const type *item) \
	310	{ \
	311	type *p = prefix ## _first(h); \
	312	int cmpval = 0; \
	313	while (p && (cmpval = cmpfn(p, item)) < 0) \
	314	p = prefix ## _next(h, p); \
	315	if (!p \|\| cmpval > 0) \
	316	return NULL; \
	317	return p; \
	318	} \
960b9a53	319	MACRO_REQUIRE_SEMICOLON() /* end */
bcea0c0f DL	320
	321	#define PREDECL_ATOMSORT_NONUNIQ(prefix) \
	322	_PREDECL_ATOMSORT(prefix)
	323	#define DECLARE_ATOMSORT_NONUNIQ(prefix, type, field, cmpfn) \
	324	\
	325	macro_inline int prefix ## __cmp(const struct atomsort_item *a, \
	326	const struct atomsort_item *b) \
	327	{ \
	328	return cmpfn(container_of(a, type, field.ai), \
	329	container_of(b, type, field.ai)); \
	330	} \
	331	macro_inline int prefix ## __cmp_uq(const struct atomsort_item *a, \
	332	const struct atomsort_item *b) \
	333	{ \
	334	int cmpval = cmpfn(container_of(a, type, field.ai), \
	335	container_of(b, type, field.ai)); \
	336	if (cmpval) \
	337	return cmpval; \
	338	if (a < b) \
	339	return -1; \
	340	if (a > b) \
	341	return 1; \
	342	return 0; \
	343	} \
	344	\
	345	_DECLARE_ATOMSORT(prefix, type, field, \
960b9a53 DL	346	prefix ## __cmp, prefix ## __cmp_uq); \
960b9a53 DL	347	MACRO_REQUIRE_SEMICOLON() /* end */
bcea0c0f DL	348
	349	struct atomsort_item atomsort_add(struct atomsort_head h,
	350	struct atomsort_item item, int (cmpfn)(
	351	const struct atomsort_item *,
	352	const struct atomsort_item *));
	353
	354	void atomsort_del_hint(struct atomsort_head *h,
5d6299d7	355	struct atomsort_item item, atomic_atomptr_t hint);
bcea0c0f DL	356
	357	struct atomsort_item atomsort_pop(struct atomsort_head h);
	358
17e38209 RW	359	#ifdef __cplusplus
	360	}
	361	#endif
	362
bcea0c0f	363	#endif /* _FRR_ATOMLIST_H */