Commit | Line | Data |
---|---|---|
61009379 MD |
1 | /* |
2 | * rcuja/rcuja.c | |
3 | * | |
4 | * Userspace RCU library - RCU Judy Array | |
5 | * | |
6 | * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
7 | * | |
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. | |
12 | * | |
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. | |
17 | * | |
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 | |
21 | */ | |
22 | ||
e5227865 | 23 | #include <stdint.h> |
8e519e3c | 24 | #include <errno.h> |
d68c6810 | 25 | #include <limits.h> |
61009379 | 26 | #include <urcu/rcuja.h> |
d68c6810 MD |
27 | #include <urcu/compiler.h> |
28 | #include <urcu/arch.h> | |
29 | #include <assert.h> | |
8e519e3c MD |
30 | #include <urcu-pointer.h> |
31 | ||
61009379 | 32 | #include "rcuja-internal.h" |
d68c6810 | 33 | #include "bitfield.h" |
61009379 | 34 | |
d68c6810 | 35 | enum rcu_ja_type_class { |
e5227865 | 36 | RCU_JA_LINEAR = 0, /* Type A */ |
fd800776 MD |
37 | /* 32-bit: 1 to 25 children, 8 to 128 bytes */ |
38 | /* 64-bit: 1 to 28 children, 16 to 256 bytes */ | |
39 | RCU_JA_POOL = 1, /* Type B */ | |
40 | /* 32-bit: 26 to 100 children, 256 to 512 bytes */ | |
41 | /* 64-bit: 29 to 112 children, 512 to 1024 bytes */ | |
e5227865 | 42 | RCU_JA_PIGEON = 2, /* Type C */ |
fd800776 MD |
43 | /* 32-bit: 101 to 256 children, 1024 bytes */ |
44 | /* 64-bit: 113 to 256 children, 2048 bytes */ | |
e5227865 | 45 | /* Leaf nodes are implicit from their height in the tree */ |
1db4943c | 46 | RCU_JA_NR_TYPES, |
e5227865 MD |
47 | }; |
48 | ||
d68c6810 MD |
49 | struct rcu_ja_type { |
50 | enum rcu_ja_type_class type_class; | |
8e519e3c MD |
51 | uint16_t min_child; /* minimum number of children: 1 to 256 */ |
52 | uint16_t max_child; /* maximum number of children: 1 to 256 */ | |
53 | uint16_t max_linear_child; /* per-pool max nr. children: 1 to 256 */ | |
54 | uint16_t order; /* node size is (1 << order), in bytes */ | |
fd800776 MD |
55 | uint16_t nr_pool_order; /* number of pools */ |
56 | uint16_t pool_size_order; /* pool size */ | |
e5227865 MD |
57 | }; |
58 | ||
d68c6810 MD |
59 | /* |
60 | * Number of least significant pointer bits reserved to represent the | |
61 | * child type. | |
62 | */ | |
63 | #define JA_TYPE_BITS 3 | |
64 | #define JA_TYPE_MAX_NR (1U << JA_TYPE_BITS) | |
65 | #define JA_TYPE_MASK (JA_TYPE_MAX_NR - 1) | |
66 | #define JA_PTR_MASK (~JA_TYPE_MASK) | |
67 | ||
68 | #define JA_ENTRY_PER_NODE 256UL | |
69 | ||
e5227865 MD |
70 | /* |
71 | * Iteration on the array to find the right node size for the number of | |
d68c6810 | 72 | * children stops when it reaches .max_child == 256 (this is the largest |
e5227865 | 73 | * possible node size, which contains 256 children). |
d68c6810 MD |
74 | * The min_child overlaps with the previous max_child to provide an |
75 | * hysteresis loop to reallocation for patterns of cyclic add/removal | |
76 | * within the same node. | |
77 | * The node the index within the following arrays is represented on 3 | |
78 | * bits. It identifies the node type, min/max number of children, and | |
79 | * the size order. | |
3d45251f MD |
80 | * The max_child values for the RCU_JA_POOL below result from |
81 | * statistical approximation: over million populations, the max_child | |
82 | * covers between 97% and 99% of the populations generated. Therefore, a | |
83 | * fallback should exist to cover the rare extreme population unbalance | |
84 | * cases, but it will not have a major impact on speed nor space | |
85 | * consumption, since those are rare cases. | |
e5227865 | 86 | */ |
e5227865 | 87 | |
d68c6810 MD |
88 | #if (CAA_BITS_PER_LONG < 64) |
89 | /* 32-bit pointers */ | |
1db4943c MD |
90 | enum { |
91 | ja_type_0_max_child = 1, | |
92 | ja_type_1_max_child = 3, | |
93 | ja_type_2_max_child = 6, | |
94 | ja_type_3_max_child = 12, | |
95 | ja_type_4_max_child = 25, | |
96 | ja_type_5_max_child = 48, | |
97 | ja_type_6_max_child = 92, | |
98 | ja_type_7_max_child = 256, | |
99 | }; | |
100 | ||
8e519e3c MD |
101 | enum { |
102 | ja_type_0_max_linear_child = 1, | |
103 | ja_type_1_max_linear_child = 3, | |
104 | ja_type_2_max_linear_child = 6, | |
105 | ja_type_3_max_linear_child = 12, | |
106 | ja_type_4_max_linear_child = 25, | |
107 | ja_type_5_max_linear_child = 24, | |
108 | ja_type_6_max_linear_child = 23, | |
109 | }; | |
110 | ||
1db4943c MD |
111 | enum { |
112 | ja_type_5_nr_pool_order = 1, | |
113 | ja_type_6_nr_pool_order = 2, | |
114 | }; | |
115 | ||
d68c6810 | 116 | const struct rcu_ja_type ja_types[] = { |
8e519e3c MD |
117 | { .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, }, |
118 | { .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, }, | |
119 | { .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, }, | |
120 | { .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, }, | |
121 | { .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, }, | |
e5227865 | 122 | |
fd800776 | 123 | /* Pools may fill sooner than max_child */ |
8e519e3c MD |
124 | { .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, }, |
125 | { .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, }, | |
3d45251f MD |
126 | |
127 | /* | |
128 | * TODO: Upon node removal below min_child, if child pool is | |
129 | * filled beyond capacity, we need to roll back to pigeon. | |
130 | */ | |
1db4943c | 131 | { .type_class = RCU_JA_PIGEON, .min_child = 89, .max_child = ja_type_7_max_child, .order = 10, }, |
d68c6810 | 132 | }; |
d68c6810 MD |
133 | #else /* !(CAA_BITS_PER_LONG < 64) */ |
134 | /* 64-bit pointers */ | |
1db4943c MD |
135 | enum { |
136 | ja_type_0_max_child = 1, | |
137 | ja_type_1_max_child = 3, | |
138 | ja_type_2_max_child = 7, | |
139 | ja_type_3_max_child = 14, | |
140 | ja_type_4_max_child = 28, | |
141 | ja_type_5_max_child = 54, | |
142 | ja_type_6_max_child = 104, | |
143 | ja_type_7_max_child = 256, | |
144 | }; | |
145 | ||
8e519e3c MD |
146 | enum { |
147 | ja_type_0_max_linear_child = 1, | |
148 | ja_type_1_max_linear_child = 3, | |
149 | ja_type_2_max_linear_child = 7, | |
150 | ja_type_3_max_linear_child = 14, | |
151 | ja_type_4_max_linear_child = 28, | |
152 | ja_type_5_max_linear_child = 27, | |
153 | ja_type_6_max_linear_child = 26, | |
154 | }; | |
155 | ||
1db4943c MD |
156 | enum { |
157 | ja_type_5_nr_pool_order = 1, | |
158 | ja_type_6_nr_pool_order = 2, | |
159 | }; | |
160 | ||
d68c6810 | 161 | const struct rcu_ja_type ja_types[] = { |
8e519e3c MD |
162 | { .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, }, |
163 | { .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, }, | |
164 | { .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, }, | |
165 | { .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, }, | |
166 | { .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, }, | |
e5227865 | 167 | |
3d45251f | 168 | /* Pools may fill sooner than max_child. */ |
8e519e3c MD |
169 | { .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, }, |
170 | { .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, }, | |
e5227865 | 171 | |
3d45251f MD |
172 | /* |
173 | * TODO: Upon node removal below min_child, if child pool is | |
174 | * filled beyond capacity, we need to roll back to pigeon. | |
175 | */ | |
1db4943c | 176 | { .type_class = RCU_JA_PIGEON, .min_child = 101, .max_child = ja_type_7_max_child, .order = 11, }, |
e5227865 | 177 | }; |
d68c6810 | 178 | #endif /* !(BITS_PER_LONG < 64) */ |
e5227865 | 179 | |
1db4943c MD |
180 | static inline __attribute__((unused)) |
181 | void static_array_size_check(void) | |
182 | { | |
183 | CAA_BUILD_BUG_ON(CAA_ARRAY_SIZE(ja_types) > JA_TYPE_MAX_NR); | |
184 | } | |
185 | ||
186 | /* Never declared. Opaque type used to store flagged node pointers. */ | |
187 | struct rcu_ja_node_flag; | |
188 | ||
e5227865 | 189 | /* |
1db4943c MD |
190 | * The rcu_ja_node contains the compressed node data needed for |
191 | * read-side. For linear and pool node configurations, it starts with a | |
192 | * byte counting the number of children in the node. Then, the | |
193 | * node-specific data is placed. | |
194 | * The node mutex, if any is needed, protecting concurrent updated of | |
195 | * each node is placed in a separate hash table indexed by node address. | |
196 | * For the pigeon configuration, the number of children is also kept in | |
197 | * a separate hash table, indexed by node address, because it is only | |
198 | * required for updates. | |
e5227865 | 199 | */ |
1db4943c MD |
200 | |
201 | #define DECLARE_LINEAR_NODE(index) \ | |
202 | struct { \ | |
203 | uint8_t nr_child; \ | |
8e519e3c MD |
204 | uint8_t child_value[ja_type_## index ##_max_linear_child]; \ |
205 | struct rcu_ja_node_flag *child_ptr[ja_type_## index ##_max_linear_child]; \ | |
1db4943c MD |
206 | } |
207 | ||
208 | #define DECLARE_POOL_NODE(index) \ | |
209 | struct { \ | |
210 | struct { \ | |
211 | uint8_t nr_child; \ | |
8e519e3c MD |
212 | uint8_t child_value[ja_type_## index ##_max_linear_child]; \ |
213 | struct rcu_ja_node_flag *child_ptr[ja_type_## index ##_max_linear_child]; \ | |
1db4943c MD |
214 | } linear[1U << ja_type_## index ##_nr_pool_order]; \ |
215 | } | |
216 | ||
e5227865 | 217 | struct rcu_ja_node { |
1db4943c MD |
218 | union { |
219 | /* Linear configuration */ | |
220 | DECLARE_LINEAR_NODE(0) conf_0; | |
221 | DECLARE_LINEAR_NODE(1) conf_1; | |
222 | DECLARE_LINEAR_NODE(2) conf_2; | |
223 | DECLARE_LINEAR_NODE(3) conf_3; | |
224 | DECLARE_LINEAR_NODE(4) conf_4; | |
225 | ||
226 | /* Pool configuration */ | |
227 | DECLARE_POOL_NODE(5) conf_5; | |
228 | DECLARE_POOL_NODE(6) conf_6; | |
229 | ||
230 | /* Pigeon configuration */ | |
231 | struct { | |
232 | struct rcu_ja_node_flag *child[ja_type_7_max_child]; | |
233 | } conf_7; | |
234 | /* data aliasing nodes for computed accesses */ | |
235 | uint8_t data[sizeof(struct rcu_ja_node_flag *) * ja_type_7_max_child]; | |
236 | } u; | |
e5227865 MD |
237 | }; |
238 | ||
d68c6810 | 239 | static |
8e519e3c MD |
240 | struct rcu_ja_node_flag *ja_node_flag(struct rcu_ja_node *node, |
241 | unsigned int type) | |
d68c6810 | 242 | { |
1db4943c | 243 | assert(type < RCU_JA_NR_TYPES); |
d68c6810 MD |
244 | return (struct rcu_ja_node_flag *) (((unsigned long) node) | type); |
245 | } | |
246 | ||
247 | static | |
248 | unsigned int ja_node_type(struct rcu_ja_node_flag *node) | |
249 | { | |
250 | unsigned int type; | |
251 | ||
252 | type = (unsigned int) ((unsigned long) node & JA_TYPE_MASK); | |
1db4943c | 253 | assert(type < RCU_JA_NR_TYPES); |
d68c6810 MD |
254 | return type; |
255 | } | |
256 | ||
257 | static | |
258 | struct rcu_ja_node *ja_node_ptr(struct rcu_ja_node_flag *node) | |
259 | { | |
260 | return (struct rcu_ja_node *) (((unsigned long) node) | JA_PTR_MASK); | |
261 | } | |
262 | ||
263 | struct rcu_ja_node *alloc_rcu_ja_node(struct rcu_ja_type *ja_type) | |
e5227865 | 264 | { |
1db4943c | 265 | return calloc(1U << ja_type->order, sizeof(char)); |
e5227865 MD |
266 | } |
267 | ||
268 | void free_rcu_ja_node(struct rcu_ja_node *node) | |
269 | { | |
270 | free(node); | |
271 | } | |
272 | ||
d68c6810 MD |
273 | #define __JA_ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask)) |
274 | #define JA_ALIGN(v, align) __JA_ALIGN_MASK(v, (typeof(v)) (align) - 1) | |
275 | #define __JA_FLOOR_MASK(v, mask) ((v) & ~(mask)) | |
276 | #define JA_FLOOR(v, align) __JA_FLOOR_MASK(v, (typeof(v)) (align) - 1) | |
277 | ||
278 | static | |
1db4943c | 279 | uint8_t *align_ptr_size(uint8_t *ptr) |
d68c6810 | 280 | { |
1db4943c | 281 | return (uint8_t *) JA_ALIGN((unsigned long) ptr, sizeof(void *)); |
d68c6810 MD |
282 | } |
283 | ||
284 | static | |
285 | struct rcu_ja_node_flag *ja_linear_node_get_nth(const struct rcu_ja_type *type, | |
8e519e3c MD |
286 | struct rcu_ja_node *node, |
287 | uint8_t n) | |
d68c6810 MD |
288 | { |
289 | uint8_t nr_child; | |
290 | uint8_t *values; | |
1db4943c | 291 | struct rcu_ja_node_flag **pointers; |
d68c6810 MD |
292 | struct rcu_ja_node_flag *ptr; |
293 | unsigned int i; | |
294 | ||
8e519e3c | 295 | assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL); |
d68c6810 | 296 | |
1db4943c | 297 | nr_child = node->u.data[0]; |
d68c6810 | 298 | cmm_smp_rmb(); /* read nr_child before values */ |
8e519e3c MD |
299 | assert(nr_child <= type->max_linear_child); |
300 | assert(type->type_class != RCU_JA_LINEAR || nr_child >= type->min_child); | |
d68c6810 | 301 | |
1db4943c | 302 | values = &node->u.data[1]; |
d68c6810 MD |
303 | for (i = 0; i < nr_child; i++) { |
304 | if (values[i] == n) | |
305 | break; | |
306 | } | |
307 | if (i >= nr_child) | |
308 | return NULL; | |
309 | cmm_smp_rmb(); /* read values before pointer */ | |
8e519e3c | 310 | pointers = (struct rcu_ja_node_flag **) align_ptr_size(&values[type->max_linear_child]); |
d68c6810 MD |
311 | ptr = pointers[i]; |
312 | assert(ja_node_ptr(ptr) != NULL); | |
313 | return ptr; | |
314 | } | |
315 | ||
d68c6810 | 316 | static |
fd800776 | 317 | struct rcu_ja_node_flag *ja_pool_node_get_nth(const struct rcu_ja_type *type, |
8e519e3c MD |
318 | struct rcu_ja_node *node, |
319 | uint8_t n) | |
d68c6810 | 320 | { |
fd800776 | 321 | struct rcu_ja_node *linear; |
d68c6810 | 322 | |
fd800776 MD |
323 | assert(type->type_class == RCU_JA_POOL); |
324 | linear = (struct rcu_ja_node *) | |
1db4943c | 325 | &node->u.data[((unsigned long) n >> (CHAR_BIT - type->nr_pool_order)) << type->pool_size_order]; |
8e519e3c | 326 | return ja_linear_node_get_nth(type, linear, n); |
d68c6810 MD |
327 | } |
328 | ||
329 | static | |
330 | struct rcu_ja_node_flag *ja_pigeon_node_get_nth(const struct rcu_ja_type *type, | |
8e519e3c MD |
331 | struct rcu_ja_node *node, |
332 | uint8_t n) | |
d68c6810 MD |
333 | { |
334 | assert(type->type_class == RCU_JA_PIGEON); | |
1db4943c | 335 | return ((struct rcu_ja_node_flag **) node->u.data)[n]; |
d68c6810 MD |
336 | } |
337 | ||
338 | /* ja_node_get_nth: get nth item from a node */ | |
339 | static | |
340 | struct rcu_ja_node_flag *ja_node_get_nth(struct rcu_ja_node_flag *node_flag, | |
8e519e3c | 341 | uint8_t n) |
d68c6810 MD |
342 | { |
343 | unsigned int type_index; | |
344 | struct rcu_ja_node *node; | |
345 | const struct rcu_ja_type *type; | |
346 | ||
347 | node_flag = rcu_dereference(node_flag); | |
348 | node = ja_node_ptr(node_flag); | |
349 | assert(node != NULL); | |
350 | type_index = ja_node_type(node_flag); | |
351 | type = &ja_types[type_index]; | |
352 | ||
353 | switch (type->type_class) { | |
354 | case RCU_JA_LINEAR: | |
355 | return ja_linear_node_get_nth(type, node, n); | |
fd800776 MD |
356 | case RCU_JA_POOL: |
357 | return ja_pool_node_get_nth(type, node, n); | |
d68c6810 MD |
358 | case RCU_JA_PIGEON: |
359 | return ja_pigeon_node_get_nth(type, node, n); | |
360 | default: | |
361 | assert(0); | |
362 | return (void *) -1UL; | |
363 | } | |
364 | } | |
365 | ||
8e519e3c MD |
366 | static |
367 | int ja_linear_node_set_nth(const struct rcu_ja_type *type, | |
368 | struct rcu_ja_node *node, | |
369 | uint8_t n, | |
370 | struct rcu_ja_node_flag *child_node_flag) | |
371 | { | |
372 | uint8_t nr_child; | |
373 | uint8_t *values, *nr_child_ptr; | |
374 | struct rcu_ja_node_flag **pointers; | |
375 | unsigned int i; | |
376 | ||
377 | assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL); | |
378 | ||
379 | nr_child_ptr = &node->u.data[0]; | |
380 | nr_child = *nr_child_ptr; | |
381 | assert(nr_child <= type->max_linear_child); | |
382 | assert(type->type_class != RCU_JA_LINEAR || nr_child >= type->min_child); | |
383 | ||
384 | values = &node->u.data[1]; | |
385 | for (i = 0; i < nr_child; i++) { | |
386 | if (values[i] == n) | |
387 | return -EEXIST; | |
388 | } | |
389 | if (nr_child >= type->max_linear_child) { | |
390 | /* No space left in this node type */ | |
391 | return -ENOSPC; | |
392 | } | |
393 | pointers = (struct rcu_ja_node_flag **) align_ptr_size(&values[type->max_linear_child]); | |
394 | pointers[nr_child] = child_node_flag; | |
395 | (*nr_child_ptr)++; | |
396 | return 0; | |
397 | } | |
398 | ||
399 | static | |
400 | int ja_pool_node_set_nth(const struct rcu_ja_type *type, | |
401 | struct rcu_ja_node *node, | |
402 | uint8_t n, | |
403 | struct rcu_ja_node_flag *child_node_flag) | |
404 | { | |
405 | struct rcu_ja_node *linear; | |
406 | ||
407 | assert(type->type_class == RCU_JA_POOL); | |
408 | linear = (struct rcu_ja_node *) | |
409 | &node->u.data[((unsigned long) n >> (CHAR_BIT - type->nr_pool_order)) << type->pool_size_order]; | |
410 | return ja_linear_node_set_nth(type, linear, n, child_node_flag); | |
411 | } | |
412 | ||
413 | static | |
414 | int ja_pigeon_node_set_nth(const struct rcu_ja_type *type, | |
415 | struct rcu_ja_node *node, | |
416 | uint8_t n, | |
417 | struct rcu_ja_node_flag *child_node_flag) | |
418 | { | |
419 | struct rcu_ja_node_flag **ptr; | |
420 | ||
421 | assert(type->type_class == RCU_JA_PIGEON); | |
422 | ptr = &((struct rcu_ja_node_flag **) node->u.data)[n]; | |
423 | if (*ptr != NULL) | |
424 | return -EEXIST; | |
425 | rcu_assign_pointer(*ptr, child_node_flag); | |
426 | return 0; | |
427 | } | |
428 | ||
d68c6810 | 429 | /* |
8e519e3c MD |
430 | * ja_node_set_nth: set nth item within a node. Return an error |
431 | * (negative error value) if it is already there. | |
432 | * TODO: exclusive access on node. | |
d68c6810 | 433 | */ |
8e519e3c MD |
434 | static |
435 | int ja_node_set_nth(struct rcu_ja_node_flag *node_flag, uint8_t n, | |
436 | struct rcu_ja_node_flag *child_node_flag) | |
437 | { | |
438 | unsigned int type_index; | |
439 | struct rcu_ja_node *node; | |
440 | const struct rcu_ja_type *type; | |
e5227865 | 441 | |
8e519e3c MD |
442 | node = ja_node_ptr(node_flag); |
443 | assert(node != NULL); | |
444 | type_index = ja_node_type(node_flag); | |
445 | type = &ja_types[type_index]; | |
446 | ||
447 | switch (type->type_class) { | |
448 | case RCU_JA_LINEAR: | |
449 | return ja_linear_node_set_nth(type, node, n, | |
450 | child_node_flag); | |
451 | case RCU_JA_POOL: | |
452 | return ja_pool_node_set_nth(type, node, n, | |
453 | child_node_flag); | |
454 | case RCU_JA_PIGEON: | |
455 | return ja_pigeon_node_set_nth(type, node, n, | |
456 | child_node_flag); | |
457 | default: | |
458 | assert(0); | |
459 | return -EINVAL; | |
460 | } | |
461 | ||
462 | return 0; | |
463 | } |