4 * Userspace RCU library - RCU Judy Array
6 * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 #include <urcu/rcuja.h>
28 #include <urcu/compiler.h>
29 #include <urcu/arch.h>
31 #include <urcu-pointer.h>
32 #include <urcu/uatomic.h>
35 #include "rcuja-internal.h"
38 enum cds_ja_type_class
{
39 RCU_JA_LINEAR
= 0, /* Type A */
40 /* 32-bit: 1 to 25 children, 8 to 128 bytes */
41 /* 64-bit: 1 to 28 children, 16 to 256 bytes */
42 RCU_JA_POOL
= 1, /* Type B */
43 /* 32-bit: 26 to 100 children, 256 to 512 bytes */
44 /* 64-bit: 29 to 112 children, 512 to 1024 bytes */
45 RCU_JA_PIGEON
= 2, /* Type C */
46 /* 32-bit: 101 to 256 children, 1024 bytes */
47 /* 64-bit: 113 to 256 children, 2048 bytes */
48 /* Leaf nodes are implicit from their height in the tree */
51 RCU_JA_NULL
, /* not an encoded type, but keeps code regular */
55 enum cds_ja_type_class type_class
;
56 uint16_t min_child
; /* minimum number of children: 1 to 256 */
57 uint16_t max_child
; /* maximum number of children: 1 to 256 */
58 uint16_t max_linear_child
; /* per-pool max nr. children: 1 to 256 */
59 uint16_t order
; /* node size is (1 << order), in bytes */
60 uint16_t nr_pool_order
; /* number of pools */
61 uint16_t pool_size_order
; /* pool size */
65 * Number of least significant pointer bits reserved to represent the
68 #define JA_TYPE_BITS 3
69 #define JA_TYPE_MAX_NR (1UL << JA_TYPE_BITS)
70 #define JA_TYPE_MASK (JA_TYPE_MAX_NR - 1)
71 #define JA_PTR_MASK (~JA_TYPE_MASK)
73 #define JA_ENTRY_PER_NODE 256UL
74 #define JA_LOG2_BITS_PER_BYTE 3U
75 #define JA_BITS_PER_BYTE (1U << JA_LOG2_BITS_PER_BYTE)
77 #define JA_MAX_DEPTH 9 /* Maximum depth, including leafs */
80 * Entry for NULL node is at index 8 of the table. It is never encoded
83 #define NODE_INDEX_NULL 8
86 * Number of removals needed on a fallback node before we try to shrink
89 #define JA_FALLBACK_REMOVAL_COUNT 8
92 * Iteration on the array to find the right node size for the number of
93 * children stops when it reaches .max_child == 256 (this is the largest
94 * possible node size, which contains 256 children).
95 * The min_child overlaps with the previous max_child to provide an
96 * hysteresis loop to reallocation for patterns of cyclic add/removal
97 * within the same node.
98 * The node the index within the following arrays is represented on 3
99 * bits. It identifies the node type, min/max number of children, and
101 * The max_child values for the RCU_JA_POOL below result from
102 * statistical approximation: over million populations, the max_child
103 * covers between 97% and 99% of the populations generated. Therefore, a
104 * fallback should exist to cover the rare extreme population unbalance
105 * cases, but it will not have a major impact on speed nor space
106 * consumption, since those are rare cases.
109 #if (CAA_BITS_PER_LONG < 64)
110 /* 32-bit pointers */
112 ja_type_0_max_child
= 1,
113 ja_type_1_max_child
= 3,
114 ja_type_2_max_child
= 6,
115 ja_type_3_max_child
= 12,
116 ja_type_4_max_child
= 25,
117 ja_type_5_max_child
= 48,
118 ja_type_6_max_child
= 92,
119 ja_type_7_max_child
= 256,
120 ja_type_8_max_child
= 0, /* NULL */
124 ja_type_0_max_linear_child
= 1,
125 ja_type_1_max_linear_child
= 3,
126 ja_type_2_max_linear_child
= 6,
127 ja_type_3_max_linear_child
= 12,
128 ja_type_4_max_linear_child
= 25,
129 ja_type_5_max_linear_child
= 24,
130 ja_type_6_max_linear_child
= 23,
134 ja_type_5_nr_pool_order
= 1,
135 ja_type_6_nr_pool_order
= 2,
138 const struct cds_ja_type ja_types
[] = {
139 { .type_class
= RCU_JA_LINEAR
, .min_child
= 1, .max_child
= ja_type_0_max_child
, .max_linear_child
= ja_type_0_max_linear_child
, .order
= 3, },
140 { .type_class
= RCU_JA_LINEAR
, .min_child
= 1, .max_child
= ja_type_1_max_child
, .max_linear_child
= ja_type_1_max_linear_child
, .order
= 4, },
141 { .type_class
= RCU_JA_LINEAR
, .min_child
= 3, .max_child
= ja_type_2_max_child
, .max_linear_child
= ja_type_2_max_linear_child
, .order
= 5, },
142 { .type_class
= RCU_JA_LINEAR
, .min_child
= 4, .max_child
= ja_type_3_max_child
, .max_linear_child
= ja_type_3_max_linear_child
, .order
= 6, },
143 { .type_class
= RCU_JA_LINEAR
, .min_child
= 10, .max_child
= ja_type_4_max_child
, .max_linear_child
= ja_type_4_max_linear_child
, .order
= 7, },
145 /* Pools may fill sooner than max_child */
146 { .type_class
= RCU_JA_POOL
, .min_child
= 20, .max_child
= ja_type_5_max_child
, .max_linear_child
= ja_type_5_max_linear_child
, .order
= 8, .nr_pool_order
= ja_type_5_nr_pool_order
, .pool_size_order
= 7, },
147 { .type_class
= RCU_JA_POOL
, .min_child
= 45, .max_child
= ja_type_6_max_child
, .max_linear_child
= ja_type_6_max_linear_child
, .order
= 9, .nr_pool_order
= ja_type_6_nr_pool_order
, .pool_size_order
= 7, },
150 * TODO: Upon node removal below min_child, if child pool is
151 * filled beyond capacity, we need to roll back to pigeon.
153 { .type_class
= RCU_JA_PIGEON
, .min_child
= 89, .max_child
= ja_type_7_max_child
, .order
= 10, },
155 { .type_class
= RCU_JA_NULL
, .min_child
= 0, .max_child
= ja_type_8_max_child
, },
157 #else /* !(CAA_BITS_PER_LONG < 64) */
158 /* 64-bit pointers */
160 ja_type_0_max_child
= 1,
161 ja_type_1_max_child
= 3,
162 ja_type_2_max_child
= 7,
163 ja_type_3_max_child
= 14,
164 ja_type_4_max_child
= 28,
165 ja_type_5_max_child
= 54,
166 ja_type_6_max_child
= 104,
167 ja_type_7_max_child
= 256,
168 ja_type_8_max_child
= 256,
172 ja_type_0_max_linear_child
= 1,
173 ja_type_1_max_linear_child
= 3,
174 ja_type_2_max_linear_child
= 7,
175 ja_type_3_max_linear_child
= 14,
176 ja_type_4_max_linear_child
= 28,
177 ja_type_5_max_linear_child
= 27,
178 ja_type_6_max_linear_child
= 26,
182 ja_type_5_nr_pool_order
= 1,
183 ja_type_6_nr_pool_order
= 2,
186 const struct cds_ja_type ja_types
[] = {
187 { .type_class
= RCU_JA_LINEAR
, .min_child
= 1, .max_child
= ja_type_0_max_child
, .max_linear_child
= ja_type_0_max_linear_child
, .order
= 4, },
188 { .type_class
= RCU_JA_LINEAR
, .min_child
= 1, .max_child
= ja_type_1_max_child
, .max_linear_child
= ja_type_1_max_linear_child
, .order
= 5, },
189 { .type_class
= RCU_JA_LINEAR
, .min_child
= 3, .max_child
= ja_type_2_max_child
, .max_linear_child
= ja_type_2_max_linear_child
, .order
= 6, },
190 { .type_class
= RCU_JA_LINEAR
, .min_child
= 5, .max_child
= ja_type_3_max_child
, .max_linear_child
= ja_type_3_max_linear_child
, .order
= 7, },
191 { .type_class
= RCU_JA_LINEAR
, .min_child
= 10, .max_child
= ja_type_4_max_child
, .max_linear_child
= ja_type_4_max_linear_child
, .order
= 8, },
193 /* Pools may fill sooner than max_child. */
194 { .type_class
= RCU_JA_POOL
, .min_child
= 22, .max_child
= ja_type_5_max_child
, .max_linear_child
= ja_type_5_max_linear_child
, .order
= 9, .nr_pool_order
= ja_type_5_nr_pool_order
, .pool_size_order
= 8, },
195 { .type_class
= RCU_JA_POOL
, .min_child
= 51, .max_child
= ja_type_6_max_child
, .max_linear_child
= ja_type_6_max_linear_child
, .order
= 10, .nr_pool_order
= ja_type_6_nr_pool_order
, .pool_size_order
= 8, },
198 * TODO: Upon node removal below min_child, if child pool is
199 * filled beyond capacity, we need to roll back to pigeon.
201 { .type_class
= RCU_JA_PIGEON
, .min_child
= 101, .max_child
= ja_type_7_max_child
, .order
= 11, },
203 { .type_class
= RCU_JA_NULL
, .min_child
= 0, .max_child
= ja_type_8_max_child
, },
205 #endif /* !(BITS_PER_LONG < 64) */
207 static inline __attribute__((unused
))
208 void static_array_size_check(void)
210 CAA_BUILD_BUG_ON(CAA_ARRAY_SIZE(ja_types
) < JA_TYPE_MAX_NR
);
214 * The cds_ja_node contains the compressed node data needed for
215 * read-side. For linear and pool node configurations, it starts with a
216 * byte counting the number of children in the node. Then, the
217 * node-specific data is placed.
218 * The node mutex, if any is needed, protecting concurrent updated of
219 * each node is placed in a separate hash table indexed by node address.
220 * For the pigeon configuration, the number of children is also kept in
221 * a separate hash table, indexed by node address, because it is only
222 * required for updates.
225 #define DECLARE_LINEAR_NODE(index) \
228 uint8_t child_value[ja_type_## index ##_max_linear_child]; \
229 struct cds_ja_inode_flag *child_ptr[ja_type_## index ##_max_linear_child]; \
232 #define DECLARE_POOL_NODE(index) \
236 uint8_t child_value[ja_type_## index ##_max_linear_child]; \
237 struct cds_ja_inode_flag *child_ptr[ja_type_## index ##_max_linear_child]; \
238 } linear[1U << ja_type_## index ##_nr_pool_order]; \
241 struct cds_ja_inode
{
243 /* Linear configuration */
244 DECLARE_LINEAR_NODE(0) conf_0
;
245 DECLARE_LINEAR_NODE(1) conf_1
;
246 DECLARE_LINEAR_NODE(2) conf_2
;
247 DECLARE_LINEAR_NODE(3) conf_3
;
248 DECLARE_LINEAR_NODE(4) conf_4
;
250 /* Pool configuration */
251 DECLARE_POOL_NODE(5) conf_5
;
252 DECLARE_POOL_NODE(6) conf_6
;
254 /* Pigeon configuration */
256 struct cds_ja_inode_flag
*child
[ja_type_7_max_child
];
258 /* data aliasing nodes for computed accesses */
259 uint8_t data
[sizeof(struct cds_ja_inode_flag
*) * ja_type_7_max_child
];
270 struct cds_ja_inode_flag
*ja_node_flag(struct cds_ja_inode
*node
,
273 assert(type
< (1UL << JA_TYPE_BITS
));
274 return (struct cds_ja_inode_flag
*) (((unsigned long) node
) | type
);
278 struct cds_ja_inode
*ja_node_ptr(struct cds_ja_inode_flag
*node
)
280 return (struct cds_ja_inode
*) (((unsigned long) node
) & JA_PTR_MASK
);
284 unsigned long ja_node_type(struct cds_ja_inode_flag
*node
)
288 if (ja_node_ptr(node
) == NULL
) {
289 return NODE_INDEX_NULL
;
291 type
= (unsigned int) ((unsigned long) node
& JA_TYPE_MASK
);
292 assert(type
< (1UL << JA_TYPE_BITS
));
296 struct cds_ja_inode
*alloc_cds_ja_node(const struct cds_ja_type
*ja_type
)
298 return calloc(1U << ja_type
->order
, sizeof(char));
301 void free_cds_ja_node(struct cds_ja_inode
*node
)
306 #define __JA_ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask))
307 #define JA_ALIGN(v, align) __JA_ALIGN_MASK(v, (typeof(v)) (align) - 1)
308 #define __JA_FLOOR_MASK(v, mask) ((v) & ~(mask))
309 #define JA_FLOOR(v, align) __JA_FLOOR_MASK(v, (typeof(v)) (align) - 1)
312 uint8_t *align_ptr_size(uint8_t *ptr
)
314 return (uint8_t *) JA_ALIGN((unsigned long) ptr
, sizeof(void *));
318 uint8_t ja_linear_node_get_nr_child(const struct cds_ja_type
*type
,
319 struct cds_ja_inode
*node
)
321 assert(type
->type_class
== RCU_JA_LINEAR
|| type
->type_class
== RCU_JA_POOL
);
322 return rcu_dereference(node
->u
.data
[0]);
326 * The order in which values and pointers are does does not matter: if
327 * a value is missing, we return NULL. If a value is there, but its
328 * associated pointers is still NULL, we return NULL too.
331 struct cds_ja_inode_flag
*ja_linear_node_get_nth(const struct cds_ja_type
*type
,
332 struct cds_ja_inode
*node
,
333 struct cds_ja_inode_flag
***child_node_flag_ptr
,
338 struct cds_ja_inode_flag
**pointers
;
339 struct cds_ja_inode_flag
*ptr
;
342 assert(type
->type_class
== RCU_JA_LINEAR
|| type
->type_class
== RCU_JA_POOL
);
344 nr_child
= ja_linear_node_get_nr_child(type
, node
);
345 cmm_smp_rmb(); /* read nr_child before values and pointers */
346 assert(nr_child
<= type
->max_linear_child
);
347 assert(type
->type_class
!= RCU_JA_LINEAR
|| nr_child
>= type
->min_child
);
349 values
= &node
->u
.data
[1];
350 for (i
= 0; i
< nr_child
; i
++) {
351 if (CMM_LOAD_SHARED(values
[i
]) == n
)
356 pointers
= (struct cds_ja_inode_flag
**) align_ptr_size(&values
[type
->max_linear_child
]);
357 ptr
= rcu_dereference(pointers
[i
]);
358 if (caa_unlikely(child_node_flag_ptr
) && ptr
)
359 *child_node_flag_ptr
= &pointers
[i
];
364 void ja_linear_node_get_ith_pos(const struct cds_ja_type
*type
,
365 struct cds_ja_inode
*node
,
368 struct cds_ja_inode_flag
**iter
)
371 struct cds_ja_inode_flag
**pointers
;
373 assert(type
->type_class
== RCU_JA_LINEAR
|| type
->type_class
== RCU_JA_POOL
);
374 assert(i
< ja_linear_node_get_nr_child(type
, node
));
376 values
= &node
->u
.data
[1];
378 pointers
= (struct cds_ja_inode_flag
**) align_ptr_size(&values
[type
->max_linear_child
]);
383 struct cds_ja_inode_flag
*ja_pool_node_get_nth(const struct cds_ja_type
*type
,
384 struct cds_ja_inode
*node
,
385 struct cds_ja_inode_flag
***child_node_flag_ptr
,
388 struct cds_ja_inode
*linear
;
390 assert(type
->type_class
== RCU_JA_POOL
);
392 * TODO: currently, we select the pool by highest bits. We
393 * should support various encodings.
395 linear
= (struct cds_ja_inode
*)
396 &node
->u
.data
[((unsigned long) n
>> (CHAR_BIT
- type
->nr_pool_order
)) << type
->pool_size_order
];
397 return ja_linear_node_get_nth(type
, linear
, child_node_flag_ptr
, n
);
401 struct cds_ja_inode
*ja_pool_node_get_ith_pool(const struct cds_ja_type
*type
,
402 struct cds_ja_inode
*node
,
405 assert(type
->type_class
== RCU_JA_POOL
);
406 return (struct cds_ja_inode
*)
407 &node
->u
.data
[(unsigned int) i
<< type
->pool_size_order
];
411 struct cds_ja_inode_flag
*ja_pigeon_node_get_nth(const struct cds_ja_type
*type
,
412 struct cds_ja_inode
*node
,
413 struct cds_ja_inode_flag
***child_node_flag_ptr
,
416 struct cds_ja_inode_flag
**child_node_flag
;
418 assert(type
->type_class
== RCU_JA_PIGEON
);
419 child_node_flag
= &((struct cds_ja_inode_flag
**) node
->u
.data
)[n
];
420 dbg_printf("ja_pigeon_node_get_nth child_node_flag_ptr %p\n",
422 if (caa_unlikely(child_node_flag_ptr
) && *child_node_flag
)
423 *child_node_flag_ptr
= child_node_flag
;
424 return rcu_dereference(*child_node_flag
);
428 struct cds_ja_inode_flag
*ja_pigeon_node_get_ith_pos(const struct cds_ja_type
*type
,
429 struct cds_ja_inode
*node
,
432 return ja_pigeon_node_get_nth(type
, node
, NULL
, i
);
436 * ja_node_get_nth: get nth item from a node.
437 * node_flag is already rcu_dereference'd.
440 struct cds_ja_inode_flag
* ja_node_get_nth(struct cds_ja_inode_flag
*node_flag
,
441 struct cds_ja_inode_flag
***child_node_flag_ptr
,
444 unsigned int type_index
;
445 struct cds_ja_inode
*node
;
446 const struct cds_ja_type
*type
;
448 node
= ja_node_ptr(node_flag
);
449 assert(node
!= NULL
);
450 type_index
= ja_node_type(node_flag
);
451 type
= &ja_types
[type_index
];
453 switch (type
->type_class
) {
455 return ja_linear_node_get_nth(type
, node
,
456 child_node_flag_ptr
, n
);
458 return ja_pool_node_get_nth(type
, node
,
459 child_node_flag_ptr
, n
);
461 return ja_pigeon_node_get_nth(type
, node
,
462 child_node_flag_ptr
, n
);
465 return (void *) -1UL;
470 int ja_linear_node_set_nth(const struct cds_ja_type
*type
,
471 struct cds_ja_inode
*node
,
472 struct cds_ja_shadow_node
*shadow_node
,
474 struct cds_ja_inode_flag
*child_node_flag
)
477 uint8_t *values
, *nr_child_ptr
;
478 struct cds_ja_inode_flag
**pointers
;
479 unsigned int i
, unused
= 0;
481 assert(type
->type_class
== RCU_JA_LINEAR
|| type
->type_class
== RCU_JA_POOL
);
483 nr_child_ptr
= &node
->u
.data
[0];
484 dbg_printf("linear set nth: nr_child_ptr %p\n", nr_child_ptr
);
485 nr_child
= *nr_child_ptr
;
486 assert(nr_child
<= type
->max_linear_child
);
488 values
= &node
->u
.data
[1];
489 pointers
= (struct cds_ja_inode_flag
**) align_ptr_size(&values
[type
->max_linear_child
]);
490 /* Check if node value is already populated */
491 for (i
= 0; i
< nr_child
; i
++) {
492 if (values
[i
] == n
) {
502 if (i
== nr_child
&& nr_child
>= type
->max_linear_child
) {
504 return -ERANGE
; /* recompact node */
506 return -ENOSPC
; /* No space left in this node type */
509 assert(pointers
[i
] == NULL
);
510 rcu_assign_pointer(pointers
[i
], child_node_flag
);
511 /* If we expanded the nr_child, increment it */
513 CMM_STORE_SHARED(values
[nr_child
], n
);
514 /* write pointer and value before nr_child */
516 CMM_STORE_SHARED(*nr_child_ptr
, nr_child
+ 1);
518 shadow_node
->nr_child
++;
519 dbg_printf("linear set nth: %u child, shadow: %u child, for node %p shadow %p\n",
520 (unsigned int) CMM_LOAD_SHARED(*nr_child_ptr
),
521 (unsigned int) shadow_node
->nr_child
,
528 int ja_pool_node_set_nth(const struct cds_ja_type
*type
,
529 struct cds_ja_inode
*node
,
530 struct cds_ja_shadow_node
*shadow_node
,
532 struct cds_ja_inode_flag
*child_node_flag
)
534 struct cds_ja_inode
*linear
;
536 assert(type
->type_class
== RCU_JA_POOL
);
537 linear
= (struct cds_ja_inode
*)
538 &node
->u
.data
[((unsigned long) n
>> (CHAR_BIT
- type
->nr_pool_order
)) << type
->pool_size_order
];
539 return ja_linear_node_set_nth(type
, linear
, shadow_node
,
544 int ja_pigeon_node_set_nth(const struct cds_ja_type
*type
,
545 struct cds_ja_inode
*node
,
546 struct cds_ja_shadow_node
*shadow_node
,
548 struct cds_ja_inode_flag
*child_node_flag
)
550 struct cds_ja_inode_flag
**ptr
;
552 assert(type
->type_class
== RCU_JA_PIGEON
);
553 ptr
= &((struct cds_ja_inode_flag
**) node
->u
.data
)[n
];
556 rcu_assign_pointer(*ptr
, child_node_flag
);
557 shadow_node
->nr_child
++;
562 * _ja_node_set_nth: set nth item within a node. Return an error
563 * (negative error value) if it is already there.
566 int _ja_node_set_nth(const struct cds_ja_type
*type
,
567 struct cds_ja_inode
*node
,
568 struct cds_ja_shadow_node
*shadow_node
,
570 struct cds_ja_inode_flag
*child_node_flag
)
572 switch (type
->type_class
) {
574 return ja_linear_node_set_nth(type
, node
, shadow_node
, n
,
577 return ja_pool_node_set_nth(type
, node
, shadow_node
, n
,
580 return ja_pigeon_node_set_nth(type
, node
, shadow_node
, n
,
593 int ja_linear_node_clear_ptr(const struct cds_ja_type
*type
,
594 struct cds_ja_inode
*node
,
595 struct cds_ja_shadow_node
*shadow_node
,
596 struct cds_ja_inode_flag
**node_flag_ptr
)
599 uint8_t *nr_child_ptr
;
601 assert(type
->type_class
== RCU_JA_LINEAR
|| type
->type_class
== RCU_JA_POOL
);
603 nr_child_ptr
= &node
->u
.data
[0];
604 dbg_printf("linear clear ptr: nr_child_ptr %p\n", nr_child_ptr
);
605 nr_child
= *nr_child_ptr
;
606 assert(nr_child
<= type
->max_linear_child
);
608 if (shadow_node
->fallback_removal_count
) {
609 shadow_node
->fallback_removal_count
--;
611 if (shadow_node
->nr_child
<= type
->min_child
) {
612 /* We need to try recompacting the node */
616 assert(*node_flag_ptr
!= NULL
);
617 rcu_assign_pointer(*node_flag_ptr
, NULL
);
619 * Value and nr_child are never changed (would cause ABA issue).
620 * Instead, we leave the pointer to NULL and recompact the node
621 * once in a while. It is allowed to set a NULL pointer to a new
622 * value without recompaction though.
623 * Only update the shadow node accounting.
625 shadow_node
->nr_child
--;
626 dbg_printf("linear clear ptr: %u child, shadow: %u child, for node %p shadow %p\n",
627 (unsigned int) CMM_LOAD_SHARED(*nr_child_ptr
),
628 (unsigned int) shadow_node
->nr_child
,
635 int ja_pool_node_clear_ptr(const struct cds_ja_type
*type
,
636 struct cds_ja_inode
*node
,
637 struct cds_ja_shadow_node
*shadow_node
,
638 struct cds_ja_inode_flag
**node_flag_ptr
,
641 struct cds_ja_inode
*linear
;
643 assert(type
->type_class
== RCU_JA_POOL
);
644 linear
= (struct cds_ja_inode
*)
645 &node
->u
.data
[((unsigned long) n
>> (CHAR_BIT
- type
->nr_pool_order
)) << type
->pool_size_order
];
646 return ja_linear_node_clear_ptr(type
, linear
, shadow_node
, node_flag_ptr
);
650 int ja_pigeon_node_clear_ptr(const struct cds_ja_type
*type
,
651 struct cds_ja_inode
*node
,
652 struct cds_ja_shadow_node
*shadow_node
,
653 struct cds_ja_inode_flag
**node_flag_ptr
)
655 assert(type
->type_class
== RCU_JA_PIGEON
);
656 rcu_assign_pointer(*node_flag_ptr
, NULL
);
657 shadow_node
->nr_child
--;
662 * _ja_node_clear_ptr: clear ptr item within a node. Return an error
663 * (negative error value) if it is not found (-ENOENT).
666 int _ja_node_clear_ptr(const struct cds_ja_type
*type
,
667 struct cds_ja_inode
*node
,
668 struct cds_ja_shadow_node
*shadow_node
,
669 struct cds_ja_inode_flag
**node_flag_ptr
,
672 switch (type
->type_class
) {
674 return ja_linear_node_clear_ptr(type
, node
, shadow_node
, node_flag_ptr
);
676 return ja_pool_node_clear_ptr(type
, node
, shadow_node
, node_flag_ptr
, n
);
678 return ja_pigeon_node_clear_ptr(type
, node
, shadow_node
, node_flag_ptr
);
690 * ja_node_recompact_add: recompact a node, adding a new child.
691 * TODO: for pool type, take selection bit(s) into account.
692 * Return 0 on success, -EAGAIN if need to retry, or other negative
693 * error value otherwise.
696 int ja_node_recompact(enum ja_recompact mode
,
698 unsigned int old_type_index
,
699 const struct cds_ja_type
*old_type
,
700 struct cds_ja_inode
*old_node
,
701 struct cds_ja_shadow_node
*shadow_node
,
702 struct cds_ja_inode_flag
**old_node_flag
, uint8_t n
,
703 struct cds_ja_inode_flag
*child_node_flag
,
704 struct cds_ja_inode_flag
**nullify_node_flag_ptr
)
706 unsigned int new_type_index
;
707 struct cds_ja_inode
*new_node
;
708 struct cds_ja_shadow_node
*new_shadow_node
= NULL
;
709 const struct cds_ja_type
*new_type
;
710 struct cds_ja_inode_flag
*new_node_flag
;
716 new_type_index
= old_type_index
;
718 case JA_RECOMPACT_ADD
:
719 if (!shadow_node
|| old_type_index
== NODE_INDEX_NULL
) {
722 new_type_index
= old_type_index
+ 1;
725 case JA_RECOMPACT_DEL
:
726 if (old_type_index
== 0) {
727 new_type_index
= NODE_INDEX_NULL
;
729 new_type_index
= old_type_index
- 1;
736 retry
: /* for fallback */
737 dbg_printf("Recompact from type %d to type %d\n",
738 old_type_index
, new_type_index
);
739 new_type
= &ja_types
[new_type_index
];
740 if (new_type_index
!= NODE_INDEX_NULL
) {
741 new_node
= alloc_cds_ja_node(new_type
);
744 new_node_flag
= ja_node_flag(new_node
, new_type_index
);
745 dbg_printf("Recompact inherit lock from %p\n", shadow_node
);
746 new_shadow_node
= rcuja_shadow_set(ja
->ht
, new_node
, shadow_node
);
747 if (!new_shadow_node
) {
752 new_shadow_node
->fallback_removal_count
=
753 JA_FALLBACK_REMOVAL_COUNT
;
756 new_node_flag
= NULL
;
759 assert(mode
!= JA_RECOMPACT_ADD
|| old_type
->type_class
!= RCU_JA_PIGEON
);
761 if (new_type_index
== NODE_INDEX_NULL
)
764 switch (old_type
->type_class
) {
768 ja_linear_node_get_nr_child(old_type
, old_node
);
771 for (i
= 0; i
< nr_child
; i
++) {
772 struct cds_ja_inode_flag
*iter
;
775 ja_linear_node_get_ith_pos(old_type
, old_node
, i
, &v
, &iter
);
778 if (mode
== JA_RECOMPACT_DEL
&& *nullify_node_flag_ptr
== iter
)
780 ret
= _ja_node_set_nth(new_type
, new_node
,
783 if (new_type
->type_class
== RCU_JA_POOL
&& ret
) {
784 goto fallback_toosmall
;
792 unsigned int pool_nr
;
794 for (pool_nr
= 0; pool_nr
< (1U << old_type
->nr_pool_order
); pool_nr
++) {
795 struct cds_ja_inode
*pool
=
796 ja_pool_node_get_ith_pool(old_type
,
799 ja_linear_node_get_nr_child(old_type
, pool
);
802 for (j
= 0; j
< nr_child
; j
++) {
803 struct cds_ja_inode_flag
*iter
;
806 ja_linear_node_get_ith_pos(old_type
, pool
,
810 if (mode
== JA_RECOMPACT_DEL
&& *nullify_node_flag_ptr
== iter
)
812 ret
= _ja_node_set_nth(new_type
, new_node
,
815 if (new_type
->type_class
== RCU_JA_POOL
817 goto fallback_toosmall
;
825 assert(mode
== JA_RECOMPACT_ADD
);
832 assert(mode
== JA_RECOMPACT_DEL
);
833 nr_child
= shadow_node
->nr_child
;
834 for (i
= 0; i
< nr_child
; i
++) {
835 struct cds_ja_inode_flag
*iter
;
837 iter
= ja_pigeon_node_get_ith_pos(old_type
, old_node
, i
);
840 if (mode
== JA_RECOMPACT_DEL
&& *nullify_node_flag_ptr
== iter
)
842 ret
= _ja_node_set_nth(new_type
, new_node
,
845 if (new_type
->type_class
== RCU_JA_POOL
&& ret
) {
846 goto fallback_toosmall
;
859 if (JA_RECOMPACT_ADD
) {
861 ret
= _ja_node_set_nth(new_type
, new_node
,
866 /* Return pointer to new recompacted node through old_node_flag */
867 *old_node_flag
= new_node_flag
;
871 flags
= RCUJA_SHADOW_CLEAR_FREE_NODE
;
873 * It is OK to free the lock associated with a node
874 * going to NULL, since we are holding the parent lock.
875 * This synchronizes removal with re-add of that node.
877 if (new_type_index
== NODE_INDEX_NULL
)
878 flags
= RCUJA_SHADOW_CLEAR_FREE_LOCK
;
879 ret
= rcuja_shadow_clear(ja
->ht
, old_node
, shadow_node
,
889 /* fallback if next pool is too small */
890 assert(new_shadow_node
);
891 ret
= rcuja_shadow_clear(ja
->ht
, new_node
, new_shadow_node
,
892 RCUJA_SHADOW_CLEAR_FREE_NODE
);
895 /* Choose fallback type: pigeon */
896 new_type_index
= (1UL << JA_TYPE_BITS
) - 1;
897 dbg_printf("Fallback to type %d\n", new_type_index
);
898 uatomic_inc(&ja
->nr_fallback
);
904 * Return 0 on success, -EAGAIN if need to retry, or other negative
905 * error value otherwise.
908 int ja_node_set_nth(struct cds_ja
*ja
,
909 struct cds_ja_inode_flag
**node_flag
, uint8_t n
,
910 struct cds_ja_inode_flag
*child_node_flag
,
911 struct cds_ja_shadow_node
*shadow_node
)
914 unsigned int type_index
;
915 const struct cds_ja_type
*type
;
916 struct cds_ja_inode
*node
;
918 dbg_printf("ja_node_set_nth for n=%u, node %p, shadow %p\n",
919 (unsigned int) n
, ja_node_ptr(*node_flag
), shadow_node
);
921 node
= ja_node_ptr(*node_flag
);
922 type_index
= ja_node_type(*node_flag
);
923 type
= &ja_types
[type_index
];
924 ret
= _ja_node_set_nth(type
, node
, shadow_node
,
928 /* Not enough space in node, need to recompact. */
929 ret
= ja_node_recompact(JA_RECOMPACT_ADD
, ja
, type_index
, type
, node
,
930 shadow_node
, node_flag
, n
, child_node_flag
, NULL
);
933 /* Node needs to be recompacted. */
934 ret
= ja_node_recompact(JA_RECOMPACT
, ja
, type_index
, type
, node
,
935 shadow_node
, node_flag
, n
, child_node_flag
, NULL
);
942 * Return 0 on success, -EAGAIN if need to retry, or other negative
943 * error value otherwise.
946 int ja_node_clear_ptr(struct cds_ja
*ja
,
947 struct cds_ja_inode_flag
**node_flag_ptr
, /* Pointer to location to nullify */
948 struct cds_ja_inode_flag
**parent_node_flag_ptr
, /* Address of parent ptr in its parent */
949 struct cds_ja_shadow_node
*shadow_node
, /* of parent */
953 unsigned int type_index
;
954 const struct cds_ja_type
*type
;
955 struct cds_ja_inode
*node
;
957 dbg_printf("ja_node_clear_ptr for node %p, shadow %p, target ptr %p\n",
958 ja_node_ptr(*parent_node_flag_ptr
), shadow_node
, node_flag_ptr
);
960 node
= ja_node_ptr(*parent_node_flag_ptr
);
961 type_index
= ja_node_type(*parent_node_flag_ptr
);
962 type
= &ja_types
[type_index
];
963 ret
= _ja_node_clear_ptr(type
, node
, shadow_node
, node_flag_ptr
, n
);
965 /* Should to try recompaction. */
966 ret
= ja_node_recompact(JA_RECOMPACT_DEL
, ja
, type_index
, type
, node
,
967 shadow_node
, parent_node_flag_ptr
, n
, NULL
,
973 struct cds_hlist_head
cds_ja_lookup(struct cds_ja
*ja
, uint64_t key
)
975 unsigned int tree_depth
, i
;
976 struct cds_ja_inode_flag
*node_flag
;
977 struct cds_hlist_head head
= { NULL
};
979 if (caa_unlikely(key
> ja
->key_max
))
981 tree_depth
= ja
->tree_depth
;
982 node_flag
= rcu_dereference(ja
->root
);
984 /* level 0: root node */
985 if (!ja_node_ptr(node_flag
))
988 for (i
= 1; i
< tree_depth
; i
++) {
991 iter_key
= (uint8_t) (key
>> (JA_BITS_PER_BYTE
* (tree_depth
- i
- 1)));
992 node_flag
= ja_node_get_nth(node_flag
, NULL
,
994 dbg_printf("cds_ja_lookup iter key lookup %u finds node_flag %p\n",
995 (unsigned int) iter_key
, node_flag
);
996 if (!ja_node_ptr(node_flag
))
1000 /* Last level lookup succeded. We got an actual match. */
1001 head
.next
= (struct cds_hlist_node
*) node_flag
;
1006 * We reached an unpopulated node. Create it and the children we need,
1007 * and then attach the entire branch to the current node. This may
1008 * trigger recompaction of the current node. Locks needed: node lock
1009 * (for add), and, possibly, parent node lock (to update pointer due to
1010 * node recompaction).
1012 * First take node lock, check if recompaction is needed, then take
1013 * parent lock (if needed). Then we can proceed to create the new
1014 * branch. Publish the new branch, and release locks.
1015 * TODO: we currently always take the parent lock even when not needed.
1018 int ja_attach_node(struct cds_ja
*ja
,
1019 struct cds_ja_inode_flag
**node_flag_ptr
,
1020 struct cds_ja_inode_flag
*node_flag
,
1021 struct cds_ja_inode_flag
*parent_node_flag
,
1024 struct cds_ja_node
*child_node
)
1026 struct cds_ja_shadow_node
*shadow_node
= NULL
,
1027 *parent_shadow_node
= NULL
;
1028 struct cds_ja_inode
*node
= ja_node_ptr(node_flag
);
1029 struct cds_ja_inode
*parent_node
= ja_node_ptr(parent_node_flag
);
1030 struct cds_hlist_head head
;
1031 struct cds_ja_inode_flag
*iter_node_flag
, *iter_dest_node_flag
;
1033 struct cds_ja_inode_flag
*created_nodes
[JA_MAX_DEPTH
];
1034 int nr_created_nodes
= 0;
1036 dbg_printf("Attach node at level %u (node %p, node_flag %p)\n",
1037 level
, node
, node_flag
);
1040 shadow_node
= rcuja_shadow_lookup_lock(ja
->ht
, node
);
1046 parent_shadow_node
= rcuja_shadow_lookup_lock(ja
->ht
,
1048 if (!parent_shadow_node
) {
1054 /* Create new branch, starting from bottom */
1055 CDS_INIT_HLIST_HEAD(&head
);
1056 cds_hlist_add_head_rcu(&child_node
->list
, &head
);
1057 iter_node_flag
= (struct cds_ja_inode_flag
*) head
.next
;
1059 for (i
= ja
->tree_depth
; i
> (int) level
; i
--) {
1062 iter_key
= (uint8_t) (key
>> (JA_BITS_PER_BYTE
* (ja
->tree_depth
- i
)));
1063 dbg_printf("branch creation level %d, key %u\n",
1064 i
- 1, (unsigned int) iter_key
);
1065 iter_dest_node_flag
= NULL
;
1066 ret
= ja_node_set_nth(ja
, &iter_dest_node_flag
,
1072 created_nodes
[nr_created_nodes
++] = iter_dest_node_flag
;
1073 iter_node_flag
= iter_dest_node_flag
;
1079 iter_key
= (uint8_t) (key
>> (JA_BITS_PER_BYTE
* (ja
->tree_depth
- level
)));
1080 /* We need to use set_nth on the previous level. */
1081 iter_dest_node_flag
= node_flag
;
1082 ret
= ja_node_set_nth(ja
, &iter_dest_node_flag
,
1088 created_nodes
[nr_created_nodes
++] = iter_dest_node_flag
;
1089 iter_node_flag
= iter_dest_node_flag
;
1092 /* Publish new branch */
1093 dbg_printf("Publish branch %p, replacing %p\n",
1094 iter_node_flag
, *node_flag_ptr
);
1095 rcu_assign_pointer(*node_flag_ptr
, iter_node_flag
);
1102 for (i
= 0; i
< nr_created_nodes
; i
++) {
1106 flags
= RCUJA_SHADOW_CLEAR_FREE_LOCK
;
1108 flags
|= RCUJA_SHADOW_CLEAR_FREE_NODE
;
1109 tmpret
= rcuja_shadow_clear(ja
->ht
,
1110 ja_node_ptr(created_nodes
[i
]),
1116 if (parent_shadow_node
)
1117 rcuja_shadow_unlock(parent_shadow_node
);
1120 rcuja_shadow_unlock(shadow_node
);
1126 * Lock the parent containing the hlist head pointer, and add node to list of
1127 * duplicates. Failure can happen if concurrent update changes the
1128 * parent before we get the lock. We return -EAGAIN in that case.
1129 * Return 0 on success, negative error value on failure.
1132 int ja_chain_node(struct cds_ja
*ja
,
1133 struct cds_ja_inode_flag
*parent_node_flag
,
1134 struct cds_hlist_head
*head
,
1135 struct cds_ja_node
*node
)
1137 struct cds_ja_shadow_node
*shadow_node
;
1139 shadow_node
= rcuja_shadow_lookup_lock(ja
->ht
,
1140 ja_node_ptr(parent_node_flag
));
1143 cds_hlist_add_head_rcu(&node
->list
, head
);
1144 rcuja_shadow_unlock(shadow_node
);
1148 int cds_ja_add(struct cds_ja
*ja
, uint64_t key
,
1149 struct cds_ja_node
*new_node
)
1151 unsigned int tree_depth
, i
;
1152 struct cds_ja_inode_flag
**node_flag_ptr
; /* in parent */
1153 struct cds_ja_inode_flag
*node_flag
,
1158 if (caa_unlikely(key
> ja
->key_max
))
1160 tree_depth
= ja
->tree_depth
;
1163 dbg_printf("cds_ja_add attempt: key %" PRIu64
", node %p\n",
1165 parent2_node_flag
= NULL
;
1167 (struct cds_ja_inode_flag
*) &ja
->root
; /* Use root ptr address as key for mutex */
1168 node_flag_ptr
= &ja
->root
;
1169 node_flag
= rcu_dereference(ja
->root
);
1171 /* Iterate on all internal levels */
1172 for (i
= 1; i
< tree_depth
; i
++) {
1175 dbg_printf("cds_ja_add iter node_flag_ptr %p node_flag %p\n",
1176 *node_flag_ptr
, node_flag
);
1177 if (!ja_node_ptr(node_flag
)) {
1178 ret
= ja_attach_node(ja
, node_flag_ptr
,
1179 parent_node_flag
, parent2_node_flag
,
1181 if (ret
== -EAGAIN
|| ret
== -EEXIST
)
1186 iter_key
= (uint8_t) (key
>> (JA_BITS_PER_BYTE
* (tree_depth
- i
- 1)));
1187 parent2_node_flag
= parent_node_flag
;
1188 parent_node_flag
= node_flag
;
1189 node_flag
= ja_node_get_nth(node_flag
,
1192 dbg_printf("cds_ja_add iter key lookup %u finds node_flag %p node_flag_ptr %p\n",
1193 (unsigned int) iter_key
, node_flag
, *node_flag_ptr
);
1197 * We reached bottom of tree, simply add node to last internal
1198 * level, or chain it if key is already present.
1200 if (!ja_node_ptr(node_flag
)) {
1201 dbg_printf("cds_ja_add last node_flag_ptr %p node_flag %p\n",
1202 *node_flag_ptr
, node_flag
);
1203 ret
= ja_attach_node(ja
, node_flag_ptr
, parent_node_flag
,
1204 parent2_node_flag
, key
, i
, new_node
);
1206 ret
= ja_chain_node(ja
,
1208 (struct cds_hlist_head
*) node_flag_ptr
,
1218 * Note: there is no need to lookup the pointer address associated with
1219 * each node's nth item after taking the lock: it's already been done by
1220 * cds_ja_del while holding the rcu read-side lock, and our node rules
1221 * ensure that when a match value -> pointer is found in a node, it is
1222 * _NEVER_ changed for that node without recompaction, and recompaction
1223 * reallocates the node.
1226 int ja_detach_node(struct cds_ja
*ja
,
1227 struct cds_ja_inode_flag
**snapshot
,
1228 struct cds_ja_inode_flag
***snapshot_ptr
,
1229 uint8_t *snapshot_n
,
1232 struct cds_ja_node
*node
)
1234 struct cds_ja_shadow_node
*shadow_nodes
[JA_MAX_DEPTH
];
1235 struct cds_ja_inode_flag
**node_flag_ptr
= NULL
,
1236 *parent_node_flag
= NULL
,
1237 **parent_node_flag_ptr
= NULL
;
1238 struct cds_ja_inode_flag
*iter_node_flag
;
1239 int ret
, i
, nr_shadow
= 0, nr_clear
= 0;
1242 assert(nr_snapshot
== ja
->tree_depth
- 1);
1245 * From the last internal level node going up, get the node
1246 * lock, check if the node has only one child left. If it is the
1247 * case, we continue iterating upward. When we reach a node
1248 * which has more that one child left, we lock the parent, and
1249 * proceed to the node deletion (removing its children too).
1251 for (i
= nr_snapshot
- 1; i
>= 1; i
--) {
1252 struct cds_ja_shadow_node
*shadow_node
;
1254 shadow_node
= rcuja_shadow_lookup_lock(ja
->ht
,
1255 ja_node_ptr(snapshot
[i
]));
1260 assert(shadow_node
->nr_child
> 0);
1261 shadow_nodes
[nr_shadow
++] = shadow_node
;
1263 if (i
== nr_snapshot
- 1) {
1265 * Re-check that last internal node level has
1266 * only one child, else trigger a retry.
1268 if (shadow_node
->nr_child
!= 1) {
1273 if (shadow_node
->nr_child
> 1 || i
== 1) {
1274 /* Lock parent and break */
1275 shadow_node
= rcuja_shadow_lookup_lock(ja
->ht
,
1276 ja_node_ptr(snapshot
[i
- 1]));
1281 shadow_nodes
[nr_shadow
++] = shadow_node
;
1282 node_flag_ptr
= snapshot_ptr
[i
];
1284 parent_node_flag_ptr
= snapshot_ptr
[i
- 1];
1285 parent_node_flag
= snapshot
[i
- 1];
1288 * Lock parent's parent, in case we need
1289 * to recompact parent.
1291 shadow_node
= rcuja_shadow_lookup_lock(ja
->ht
,
1292 ja_node_ptr(snapshot
[i
- 2]));
1297 shadow_nodes
[nr_shadow
++] = shadow_node
;
1304 * At this point, we want to delete all nodes in shadow_nodes
1305 * (except the last one, which is either the root or the parent
1306 * of the upmost node with 1 child). OK to as to free lock here,
1307 * because RCU read lock is held, and free only performed in
1311 for (i
= 0; i
< nr_clear
; i
++) {
1312 ret
= rcuja_shadow_clear(ja
->ht
,
1313 shadow_nodes
[i
]->node
,
1315 RCUJA_SHADOW_CLEAR_FREE_NODE
1316 | RCUJA_SHADOW_CLEAR_FREE_LOCK
);
1320 iter_node_flag
= parent_node_flag
;
1321 /* Remove from parent */
1322 ret
= ja_node_clear_ptr(ja
,
1323 node_flag_ptr
, /* Pointer to location to nullify */
1324 &iter_node_flag
, /* Old new parent ptr in its parent */
1325 shadow_nodes
[nr_clear
], /* of parent */
1328 /* Update address of parent ptr in its parent */
1329 rcu_assign_pointer(*parent_node_flag_ptr
, iter_node_flag
);
1332 for (i
= 0; i
< nr_shadow
; i
++)
1333 rcuja_shadow_unlock(shadow_nodes
[i
]);
1338 int ja_unchain_node(struct cds_ja
*ja
,
1339 struct cds_ja_inode_flag
*parent_node_flag
,
1340 struct cds_ja_node
*node
)
1342 struct cds_ja_shadow_node
*shadow_node
;
1345 shadow_node
= rcuja_shadow_lookup_lock(ja
->ht
,
1346 ja_node_ptr(parent_node_flag
));
1350 * Retry if another thread removed all but one of duplicates
1353 if (shadow_node
->nr_child
== 1) {
1357 cds_hlist_del_rcu(&node
->list
);
1359 rcuja_shadow_unlock(shadow_node
);
1364 * Called with RCU read lock held.
1366 int cds_ja_del(struct cds_ja
*ja
, uint64_t key
,
1367 struct cds_ja_node
*node
)
1369 unsigned int tree_depth
, i
;
1370 struct cds_ja_inode_flag
*snapshot
[JA_MAX_DEPTH
];
1371 struct cds_ja_inode_flag
**snapshot_ptr
[JA_MAX_DEPTH
];
1372 uint8_t snapshot_n
[JA_MAX_DEPTH
];
1373 struct cds_ja_inode_flag
*node_flag
;
1374 struct cds_ja_inode_flag
**prev_node_flag_ptr
;
1375 int nr_snapshot
= 0;
1378 if (caa_unlikely(key
> ja
->key_max
))
1380 tree_depth
= ja
->tree_depth
;
1383 dbg_printf("cds_ja_del attempt: key %" PRIu64
", node %p\n",
1386 /* snapshot for level 0 is only for shadow node lookup */
1387 snapshot_n
[nr_snapshot
] = 0;
1388 snapshot_ptr
[nr_snapshot
] = NULL
;
1389 snapshot
[nr_snapshot
++] = (struct cds_ja_inode_flag
*) &ja
->root
;
1390 node_flag
= rcu_dereference(ja
->root
);
1391 prev_node_flag_ptr
= &ja
->root
;
1393 /* Iterate on all internal levels */
1394 for (i
= 1; i
< tree_depth
; i
++) {
1397 dbg_printf("cds_ja_del iter node_flag %p\n",
1399 if (!ja_node_ptr(node_flag
)) {
1402 iter_key
= (uint8_t) (key
>> (JA_BITS_PER_BYTE
* (tree_depth
- i
- 1)));
1403 if (nr_snapshot
<= 1)
1404 snapshot_n
[nr_snapshot
] = 0;
1406 snapshot_n
[nr_snapshot
- 1] = iter_key
;
1408 snapshot_ptr
[nr_snapshot
] = prev_node_flag_ptr
;
1409 snapshot
[nr_snapshot
++] = node_flag
;
1410 node_flag
= ja_node_get_nth(node_flag
,
1411 &prev_node_flag_ptr
,
1413 dbg_printf("cds_ja_del iter key lookup %u finds node_flag %p, prev_node_flag_ptr %p\n",
1414 (unsigned int) iter_key
, node_flag
,
1415 prev_node_flag_ptr
);
1419 * We reached bottom of tree, try to find the node we are trying
1420 * to remove. Fail if we cannot find it.
1422 if (!ja_node_ptr(node_flag
)) {
1425 struct cds_hlist_head
*hlist_head
;
1426 struct cds_hlist_node
*hlist_node
;
1427 struct cds_ja_node
*entry
, *match
= NULL
;
1430 hlist_head
= (struct cds_hlist_head
*) ja_node_ptr(node_flag
);
1431 cds_hlist_for_each_entry_rcu(entry
,
1444 * Removing last of duplicates.
1446 snapshot_ptr
[nr_snapshot
] = prev_node_flag_ptr
;
1447 snapshot
[nr_snapshot
++] = node_flag
;
1448 ret
= ja_detach_node(ja
, snapshot
, snapshot_ptr
,
1449 snapshot_n
, nr_snapshot
, key
, node
);
1451 ret
= ja_unchain_node(ja
, node_flag
, entry
);
1459 struct cds_ja
*_cds_ja_new(unsigned int key_bits
,
1460 const struct rcu_flavor_struct
*flavor
)
1464 struct cds_ja_shadow_node
*root_shadow_node
;
1466 ja
= calloc(sizeof(*ja
), 1);
1472 ja
->key_max
= UINT8_MAX
;
1475 ja
->key_max
= UINT16_MAX
;
1478 ja
->key_max
= UINT32_MAX
;
1481 ja
->key_max
= UINT64_MAX
;
1487 /* ja->root is NULL */
1488 /* tree_depth 0 is for pointer to root node */
1489 ja
->tree_depth
= (key_bits
>> JA_LOG2_BITS_PER_BYTE
) + 1;
1490 assert(ja
->tree_depth
<= JA_MAX_DEPTH
);
1491 ja
->ht
= rcuja_create_ht(flavor
);
1496 * Note: we should not free this node until judy array destroy.
1498 root_shadow_node
= rcuja_shadow_set(ja
->ht
,
1499 ja_node_ptr((struct cds_ja_inode_flag
*) &ja
->root
),
1501 if (!root_shadow_node
) {
1505 root_shadow_node
->is_root
= 1;
1510 ret
= rcuja_delete_ht(ja
->ht
);
1520 * There should be no more concurrent add to the judy array while it is
1521 * being destroyed (ensured by the caller).
1523 int cds_ja_destroy(struct cds_ja
*ja
)
1527 rcuja_shadow_prune(ja
->ht
,
1528 RCUJA_SHADOW_CLEAR_FREE_NODE
| RCUJA_SHADOW_CLEAR_FREE_LOCK
);
1529 ret
= rcuja_delete_ht(ja
->ht
);
1532 if (uatomic_read(&ja
->nr_fallback
))
1534 "[warning] RCU Judy Array used %lu fallback node(s)\n",
1535 uatomic_read(&ja
->nr_fallback
));