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5e28c532 | 1 | /* |
abc490a1 MD |
2 | * rculfhash.c |
3 | * | |
1475579c | 4 | * Userspace RCU library - Lock-Free Resizable RCU Hash Table |
abc490a1 MD |
5 | * |
6 | * Copyright 2010-2011 - 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 | |
5e28c532 MD |
21 | */ |
22 | ||
e753ff5a MD |
23 | /* |
24 | * Based on the following articles: | |
25 | * - Ori Shalev and Nir Shavit. Split-ordered lists: Lock-free | |
26 | * extensible hash tables. J. ACM 53, 3 (May 2006), 379-405. | |
27 | * - Michael, M. M. High performance dynamic lock-free hash tables | |
28 | * and list-based sets. In Proceedings of the fourteenth annual ACM | |
29 | * symposium on Parallel algorithms and architectures, ACM Press, | |
30 | * (2002), 73-82. | |
31 | * | |
1475579c | 32 | * Some specificities of this Lock-Free Resizable RCU Hash Table |
e753ff5a MD |
33 | * implementation: |
34 | * | |
35 | * - RCU read-side critical section allows readers to perform hash | |
36 | * table lookups and use the returned objects safely by delaying | |
37 | * memory reclaim of a grace period. | |
38 | * - Add and remove operations are lock-free, and do not need to | |
39 | * allocate memory. They need to be executed within RCU read-side | |
40 | * critical section to ensure the objects they read are valid and to | |
41 | * deal with the cmpxchg ABA problem. | |
42 | * - add and add_unique operations are supported. add_unique checks if | |
43 | * the node key already exists in the hash table. It ensures no key | |
44 | * duplicata exists. | |
45 | * - The resize operation executes concurrently with add/remove/lookup. | |
46 | * - Hash table nodes are contained within a split-ordered list. This | |
47 | * list is ordered by incrementing reversed-bits-hash value. | |
48 | * - An index of dummy nodes is kept. These dummy nodes are the hash | |
49 | * table "buckets", and they are also chained together in the | |
50 | * split-ordered list, which allows recursive expansion. | |
1475579c MD |
51 | * - The resize operation for small tables only allows expanding the hash table. |
52 | * It is triggered automatically by detecting long chains in the add | |
53 | * operation. | |
54 | * - The resize operation for larger tables (and available through an | |
55 | * API) allows both expanding and shrinking the hash table. | |
56 | * - Per-CPU Split-counters are used to keep track of the number of | |
57 | * nodes within the hash table for automatic resize triggering. | |
e753ff5a MD |
58 | * - Resize operation initiated by long chain detection is executed by a |
59 | * call_rcu thread, which keeps lock-freedom of add and remove. | |
60 | * - Resize operations are protected by a mutex. | |
61 | * - The removal operation is split in two parts: first, a "removed" | |
62 | * flag is set in the next pointer within the node to remove. Then, | |
63 | * a "garbage collection" is performed in the bucket containing the | |
64 | * removed node (from the start of the bucket up to the removed node). | |
65 | * All encountered nodes with "removed" flag set in their next | |
66 | * pointers are removed from the linked-list. If the cmpxchg used for | |
67 | * removal fails (due to concurrent garbage-collection or concurrent | |
68 | * add), we retry from the beginning of the bucket. This ensures that | |
69 | * the node with "removed" flag set is removed from the hash table | |
70 | * (not visible to lookups anymore) before the RCU read-side critical | |
71 | * section held across removal ends. Furthermore, this ensures that | |
72 | * the node with "removed" flag set is removed from the linked-list | |
73 | * before its memory is reclaimed. Only the thread which removal | |
74 | * successfully set the "removed" flag (with a cmpxchg) into a node's | |
75 | * next pointer is considered to have succeeded its removal (and thus | |
76 | * owns the node to reclaim). Because we garbage-collect starting from | |
77 | * an invariant node (the start-of-bucket dummy node) up to the | |
78 | * "removed" node (or find a reverse-hash that is higher), we are sure | |
79 | * that a successful traversal of the chain leads to a chain that is | |
80 | * present in the linked-list (the start node is never removed) and | |
81 | * that is does not contain the "removed" node anymore, even if | |
82 | * concurrent delete/add operations are changing the structure of the | |
83 | * list concurrently. | |
29e669f6 MD |
84 | * - The add operation performs gargage collection of buckets if it |
85 | * encounters nodes with removed flag set in the bucket where it wants | |
86 | * to add its new node. This ensures lock-freedom of add operation by | |
87 | * helping the remover unlink nodes from the list rather than to wait | |
88 | * for it do to so. | |
e753ff5a MD |
89 | * - A RCU "order table" indexed by log2(hash index) is copied and |
90 | * expanded by the resize operation. This order table allows finding | |
91 | * the "dummy node" tables. | |
92 | * - There is one dummy node table per hash index order. The size of | |
93 | * each dummy node table is half the number of hashes contained in | |
94 | * this order. | |
95 | * - call_rcu is used to garbage-collect the old order table. | |
96 | * - The per-order dummy node tables contain a compact version of the | |
97 | * hash table nodes. These tables are invariant after they are | |
98 | * populated into the hash table. | |
1475579c MD |
99 | * |
100 | * A bit of ascii art explanation: | |
101 | * | |
102 | * Order index is the off-by-one compare to the actual power of 2 because | |
103 | * we use index 0 to deal with the 0 special-case. | |
104 | * | |
105 | * This shows the nodes for a small table ordered by reversed bits: | |
106 | * | |
107 | * bits reverse | |
108 | * 0 000 000 | |
109 | * 4 100 001 | |
110 | * 2 010 010 | |
111 | * 6 110 011 | |
112 | * 1 001 100 | |
113 | * 5 101 101 | |
114 | * 3 011 110 | |
115 | * 7 111 111 | |
116 | * | |
117 | * This shows the nodes in order of non-reversed bits, linked by | |
118 | * reversed-bit order. | |
119 | * | |
120 | * order bits reverse | |
121 | * 0 0 000 000 | |
122 | * | | |
f6fdd688 MD |
123 | * 1 | 1 001 100 <- <- |
124 | * | | | | | |
125 | * 2 | | 2 010 010 | | | |
126 | * | | | 3 011 110 | <- | | |
127 | * | | | | | | | | |
1475579c MD |
128 | * 3 -> | | | 4 100 001 | | |
129 | * -> | | 5 101 101 | | |
130 | * -> | 6 110 011 | |
131 | * -> 7 111 111 | |
e753ff5a MD |
132 | */ |
133 | ||
2ed95849 MD |
134 | #define _LGPL_SOURCE |
135 | #include <stdlib.h> | |
e0ba718a MD |
136 | #include <errno.h> |
137 | #include <assert.h> | |
138 | #include <stdio.h> | |
abc490a1 | 139 | #include <stdint.h> |
f000907d | 140 | #include <string.h> |
e0ba718a | 141 | |
df44348d | 142 | #include "config.h" |
2ed95849 | 143 | #include <urcu.h> |
abc490a1 | 144 | #include <urcu-call-rcu.h> |
a42cc659 MD |
145 | #include <urcu/arch.h> |
146 | #include <urcu/uatomic.h> | |
674f7a69 | 147 | #include <urcu/jhash.h> |
a42cc659 | 148 | #include <urcu/compiler.h> |
abc490a1 | 149 | #include <urcu/rculfhash.h> |
5e28c532 | 150 | #include <stdio.h> |
464a1ec9 | 151 | #include <pthread.h> |
44395fb7 | 152 | |
f9830efd | 153 | #ifdef DEBUG |
f0c29ed7 | 154 | #define dbg_printf(fmt, args...) printf("[debug rculfhash] " fmt, ## args) |
f9830efd | 155 | #else |
e753ff5a | 156 | #define dbg_printf(fmt, args...) |
f9830efd MD |
157 | #endif |
158 | ||
f8994aee MD |
159 | /* |
160 | * Per-CPU split-counters lazily update the global counter each 1024 | |
161 | * addition/removal. It automatically keeps track of resize required. | |
162 | * We use the bucket length as indicator for need to expand for small | |
163 | * tables and machines lacking per-cpu data suppport. | |
164 | */ | |
165 | #define COUNT_COMMIT_ORDER 10 | |
6ea6bc67 MD |
166 | #define CHAIN_LEN_TARGET 1 |
167 | #define CHAIN_LEN_RESIZE_THRESHOLD 3 | |
2ed95849 | 168 | |
cd95516d | 169 | /* |
76a73da8 | 170 | * Define the minimum table size. |
cd95516d | 171 | */ |
c9edd44a | 172 | #define MIN_TABLE_SIZE 1 |
cd95516d | 173 | |
4105056a MD |
174 | #if (CAA_BITS_PER_LONG == 32) |
175 | #define MAX_TABLE_ORDER 32 | |
176 | #else | |
177 | #define MAX_TABLE_ORDER 64 | |
178 | #endif | |
179 | ||
180 | #ifndef min | |
181 | #define min(a, b) ((a) < (b) ? (a) : (b)) | |
182 | #endif | |
183 | ||
abc490a1 MD |
184 | #ifndef max |
185 | #define max(a, b) ((a) > (b) ? (a) : (b)) | |
186 | #endif | |
2ed95849 | 187 | |
d95bd160 MD |
188 | /* |
189 | * The removed flag needs to be updated atomically with the pointer. | |
190 | * The dummy flag does not require to be updated atomically with the | |
191 | * pointer, but it is added as a pointer low bit flag to save space. | |
192 | */ | |
d37166c6 | 193 | #define REMOVED_FLAG (1UL << 0) |
f5596c94 MD |
194 | #define DUMMY_FLAG (1UL << 1) |
195 | #define FLAGS_MASK ((1UL << 2) - 1) | |
d37166c6 | 196 | |
bb7b2f26 | 197 | /* Value of the end pointer. Should not interact with flags. */ |
f9c80341 | 198 | #define END_VALUE NULL |
bb7b2f26 | 199 | |
df44348d | 200 | struct ht_items_count { |
3171717f | 201 | unsigned long add, remove; |
df44348d MD |
202 | } __attribute__((aligned(CAA_CACHE_LINE_SIZE))); |
203 | ||
1475579c MD |
204 | struct rcu_level { |
205 | struct rcu_head head; | |
206 | struct _cds_lfht_node nodes[0]; | |
207 | }; | |
208 | ||
395270b6 | 209 | struct rcu_table { |
4105056a | 210 | unsigned long size; /* always a power of 2, shared (RCU) */ |
f9830efd | 211 | unsigned long resize_target; |
11519af6 | 212 | int resize_initiated; |
4105056a | 213 | struct rcu_level *tbl[MAX_TABLE_ORDER]; |
395270b6 MD |
214 | }; |
215 | ||
14044b37 | 216 | struct cds_lfht { |
4105056a | 217 | struct rcu_table t; |
14044b37 MD |
218 | cds_lfht_hash_fct hash_fct; |
219 | cds_lfht_compare_fct compare_fct; | |
732ad076 | 220 | unsigned long hash_seed; |
b8af5011 | 221 | int flags; |
5f511391 MD |
222 | /* |
223 | * We need to put the work threads offline (QSBR) when taking this | |
224 | * mutex, because we use synchronize_rcu within this mutex critical | |
225 | * section, which waits on read-side critical sections, and could | |
226 | * therefore cause grace-period deadlock if we hold off RCU G.P. | |
227 | * completion. | |
228 | */ | |
464a1ec9 | 229 | pthread_mutex_t resize_mutex; /* resize mutex: add/del mutex */ |
33c7c748 | 230 | unsigned int in_progress_resize, in_progress_destroy; |
14044b37 | 231 | void (*cds_lfht_call_rcu)(struct rcu_head *head, |
abc490a1 | 232 | void (*func)(struct rcu_head *head)); |
1475579c | 233 | void (*cds_lfht_synchronize_rcu)(void); |
01dbfa62 MD |
234 | void (*cds_lfht_rcu_read_lock)(void); |
235 | void (*cds_lfht_rcu_read_unlock)(void); | |
5f511391 MD |
236 | void (*cds_lfht_rcu_thread_offline)(void); |
237 | void (*cds_lfht_rcu_thread_online)(void); | |
df44348d MD |
238 | unsigned long count; /* global approximate item count */ |
239 | struct ht_items_count *percpu_count; /* per-cpu item count */ | |
2ed95849 MD |
240 | }; |
241 | ||
abc490a1 MD |
242 | struct rcu_resize_work { |
243 | struct rcu_head head; | |
14044b37 | 244 | struct cds_lfht *ht; |
abc490a1 | 245 | }; |
2ed95849 | 246 | |
76a73da8 MD |
247 | static |
248 | struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht, | |
249 | unsigned long size, | |
250 | struct cds_lfht_node *node, | |
251 | int unique, int dummy); | |
252 | ||
abc490a1 MD |
253 | /* |
254 | * Algorithm to reverse bits in a word by lookup table, extended to | |
255 | * 64-bit words. | |
f9830efd | 256 | * Source: |
abc490a1 | 257 | * http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable |
f9830efd | 258 | * Originally from Public Domain. |
abc490a1 MD |
259 | */ |
260 | ||
261 | static const uint8_t BitReverseTable256[256] = | |
2ed95849 | 262 | { |
abc490a1 MD |
263 | #define R2(n) (n), (n) + 2*64, (n) + 1*64, (n) + 3*64 |
264 | #define R4(n) R2(n), R2((n) + 2*16), R2((n) + 1*16), R2((n) + 3*16) | |
265 | #define R6(n) R4(n), R4((n) + 2*4 ), R4((n) + 1*4 ), R4((n) + 3*4 ) | |
266 | R6(0), R6(2), R6(1), R6(3) | |
267 | }; | |
268 | #undef R2 | |
269 | #undef R4 | |
270 | #undef R6 | |
2ed95849 | 271 | |
abc490a1 MD |
272 | static |
273 | uint8_t bit_reverse_u8(uint8_t v) | |
274 | { | |
275 | return BitReverseTable256[v]; | |
276 | } | |
ab7d5fc6 | 277 | |
abc490a1 MD |
278 | static __attribute__((unused)) |
279 | uint32_t bit_reverse_u32(uint32_t v) | |
280 | { | |
281 | return ((uint32_t) bit_reverse_u8(v) << 24) | | |
282 | ((uint32_t) bit_reverse_u8(v >> 8) << 16) | | |
283 | ((uint32_t) bit_reverse_u8(v >> 16) << 8) | | |
284 | ((uint32_t) bit_reverse_u8(v >> 24)); | |
2ed95849 MD |
285 | } |
286 | ||
abc490a1 MD |
287 | static __attribute__((unused)) |
288 | uint64_t bit_reverse_u64(uint64_t v) | |
2ed95849 | 289 | { |
abc490a1 MD |
290 | return ((uint64_t) bit_reverse_u8(v) << 56) | |
291 | ((uint64_t) bit_reverse_u8(v >> 8) << 48) | | |
292 | ((uint64_t) bit_reverse_u8(v >> 16) << 40) | | |
293 | ((uint64_t) bit_reverse_u8(v >> 24) << 32) | | |
294 | ((uint64_t) bit_reverse_u8(v >> 32) << 24) | | |
295 | ((uint64_t) bit_reverse_u8(v >> 40) << 16) | | |
296 | ((uint64_t) bit_reverse_u8(v >> 48) << 8) | | |
297 | ((uint64_t) bit_reverse_u8(v >> 56)); | |
298 | } | |
299 | ||
300 | static | |
301 | unsigned long bit_reverse_ulong(unsigned long v) | |
302 | { | |
303 | #if (CAA_BITS_PER_LONG == 32) | |
304 | return bit_reverse_u32(v); | |
305 | #else | |
306 | return bit_reverse_u64(v); | |
307 | #endif | |
308 | } | |
309 | ||
f9830efd | 310 | /* |
24365af7 MD |
311 | * fls: returns the position of the most significant bit. |
312 | * Returns 0 if no bit is set, else returns the position of the most | |
313 | * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit). | |
f9830efd | 314 | */ |
24365af7 MD |
315 | #if defined(__i386) || defined(__x86_64) |
316 | static inline | |
317 | unsigned int fls_u32(uint32_t x) | |
f9830efd | 318 | { |
24365af7 MD |
319 | int r; |
320 | ||
321 | asm("bsrl %1,%0\n\t" | |
322 | "jnz 1f\n\t" | |
323 | "movl $-1,%0\n\t" | |
324 | "1:\n\t" | |
325 | : "=r" (r) : "rm" (x)); | |
326 | return r + 1; | |
327 | } | |
328 | #define HAS_FLS_U32 | |
329 | #endif | |
330 | ||
331 | #if defined(__x86_64) | |
332 | static inline | |
333 | unsigned int fls_u64(uint64_t x) | |
334 | { | |
335 | long r; | |
336 | ||
337 | asm("bsrq %1,%0\n\t" | |
338 | "jnz 1f\n\t" | |
339 | "movq $-1,%0\n\t" | |
340 | "1:\n\t" | |
341 | : "=r" (r) : "rm" (x)); | |
342 | return r + 1; | |
343 | } | |
344 | #define HAS_FLS_U64 | |
345 | #endif | |
346 | ||
347 | #ifndef HAS_FLS_U64 | |
348 | static __attribute__((unused)) | |
349 | unsigned int fls_u64(uint64_t x) | |
350 | { | |
351 | unsigned int r = 64; | |
352 | ||
353 | if (!x) | |
354 | return 0; | |
355 | ||
356 | if (!(x & 0xFFFFFFFF00000000ULL)) { | |
357 | x <<= 32; | |
358 | r -= 32; | |
359 | } | |
360 | if (!(x & 0xFFFF000000000000ULL)) { | |
361 | x <<= 16; | |
362 | r -= 16; | |
363 | } | |
364 | if (!(x & 0xFF00000000000000ULL)) { | |
365 | x <<= 8; | |
366 | r -= 8; | |
367 | } | |
368 | if (!(x & 0xF000000000000000ULL)) { | |
369 | x <<= 4; | |
370 | r -= 4; | |
371 | } | |
372 | if (!(x & 0xC000000000000000ULL)) { | |
373 | x <<= 2; | |
374 | r -= 2; | |
375 | } | |
376 | if (!(x & 0x8000000000000000ULL)) { | |
377 | x <<= 1; | |
378 | r -= 1; | |
379 | } | |
380 | return r; | |
381 | } | |
382 | #endif | |
383 | ||
384 | #ifndef HAS_FLS_U32 | |
385 | static __attribute__((unused)) | |
386 | unsigned int fls_u32(uint32_t x) | |
387 | { | |
388 | unsigned int r = 32; | |
f9830efd | 389 | |
24365af7 MD |
390 | if (!x) |
391 | return 0; | |
392 | if (!(x & 0xFFFF0000U)) { | |
393 | x <<= 16; | |
394 | r -= 16; | |
395 | } | |
396 | if (!(x & 0xFF000000U)) { | |
397 | x <<= 8; | |
398 | r -= 8; | |
399 | } | |
400 | if (!(x & 0xF0000000U)) { | |
401 | x <<= 4; | |
402 | r -= 4; | |
403 | } | |
404 | if (!(x & 0xC0000000U)) { | |
405 | x <<= 2; | |
406 | r -= 2; | |
407 | } | |
408 | if (!(x & 0x80000000U)) { | |
409 | x <<= 1; | |
410 | r -= 1; | |
411 | } | |
412 | return r; | |
413 | } | |
414 | #endif | |
415 | ||
416 | unsigned int fls_ulong(unsigned long x) | |
f9830efd | 417 | { |
24365af7 MD |
418 | #if (CAA_BITS_PER_lONG == 32) |
419 | return fls_u32(x); | |
420 | #else | |
421 | return fls_u64(x); | |
422 | #endif | |
423 | } | |
f9830efd | 424 | |
24365af7 MD |
425 | int get_count_order_u32(uint32_t x) |
426 | { | |
427 | int order; | |
428 | ||
429 | order = fls_u32(x) - 1; | |
430 | if (x & (x - 1)) | |
431 | order++; | |
432 | return order; | |
433 | } | |
434 | ||
435 | int get_count_order_ulong(unsigned long x) | |
436 | { | |
437 | int order; | |
438 | ||
439 | order = fls_ulong(x) - 1; | |
440 | if (x & (x - 1)) | |
441 | order++; | |
442 | return order; | |
f9830efd MD |
443 | } |
444 | ||
98808fb1 MD |
445 | #ifdef POISON_FREE |
446 | #define poison_free(ptr) \ | |
447 | do { \ | |
448 | memset(ptr, 0x42, sizeof(*(ptr))); \ | |
449 | free(ptr); \ | |
450 | } while (0) | |
451 | #else | |
452 | #define poison_free(ptr) free(ptr) | |
453 | #endif | |
454 | ||
f9830efd | 455 | static |
4105056a | 456 | void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth); |
f9830efd | 457 | |
df44348d MD |
458 | /* |
459 | * If the sched_getcpu() and sysconf(_SC_NPROCESSORS_CONF) calls are | |
460 | * available, then we support hash table item accounting. | |
461 | * In the unfortunate event the number of CPUs reported would be | |
462 | * inaccurate, we use modulo arithmetic on the number of CPUs we got. | |
463 | */ | |
df44348d MD |
464 | #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) |
465 | ||
f8994aee | 466 | static |
4105056a | 467 | void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size, |
f8994aee MD |
468 | unsigned long count); |
469 | ||
df44348d MD |
470 | static long nr_cpus_mask = -1; |
471 | ||
472 | static | |
473 | struct ht_items_count *alloc_per_cpu_items_count(void) | |
474 | { | |
475 | struct ht_items_count *count; | |
476 | ||
477 | switch (nr_cpus_mask) { | |
478 | case -2: | |
479 | return NULL; | |
480 | case -1: | |
481 | { | |
482 | long maxcpus; | |
483 | ||
484 | maxcpus = sysconf(_SC_NPROCESSORS_CONF); | |
485 | if (maxcpus <= 0) { | |
486 | nr_cpus_mask = -2; | |
487 | return NULL; | |
488 | } | |
489 | /* | |
490 | * round up number of CPUs to next power of two, so we | |
491 | * can use & for modulo. | |
492 | */ | |
493 | maxcpus = 1UL << get_count_order_ulong(maxcpus); | |
494 | nr_cpus_mask = maxcpus - 1; | |
495 | } | |
496 | /* Fall-through */ | |
497 | default: | |
498 | return calloc(nr_cpus_mask + 1, sizeof(*count)); | |
499 | } | |
500 | } | |
501 | ||
502 | static | |
503 | void free_per_cpu_items_count(struct ht_items_count *count) | |
504 | { | |
98808fb1 | 505 | poison_free(count); |
df44348d MD |
506 | } |
507 | ||
508 | static | |
509 | int ht_get_cpu(void) | |
510 | { | |
511 | int cpu; | |
512 | ||
513 | assert(nr_cpus_mask >= 0); | |
514 | cpu = sched_getcpu(); | |
515 | if (unlikely(cpu < 0)) | |
516 | return cpu; | |
517 | else | |
518 | return cpu & nr_cpus_mask; | |
519 | } | |
520 | ||
521 | static | |
4105056a | 522 | void ht_count_add(struct cds_lfht *ht, unsigned long size) |
df44348d | 523 | { |
3171717f | 524 | unsigned long percpu_count; |
df44348d MD |
525 | int cpu; |
526 | ||
527 | if (unlikely(!ht->percpu_count)) | |
3171717f | 528 | return; |
df44348d MD |
529 | cpu = ht_get_cpu(); |
530 | if (unlikely(cpu < 0)) | |
3171717f MD |
531 | return; |
532 | percpu_count = uatomic_add_return(&ht->percpu_count[cpu].add, 1); | |
df44348d MD |
533 | if (unlikely(!(percpu_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) { |
534 | unsigned long count; | |
535 | ||
536 | dbg_printf("add percpu %lu\n", percpu_count); | |
537 | count = uatomic_add_return(&ht->count, | |
538 | 1UL << COUNT_COMMIT_ORDER); | |
539 | /* If power of 2 */ | |
540 | if (!(count & (count - 1))) { | |
4105056a | 541 | if ((count >> CHAIN_LEN_RESIZE_THRESHOLD) < size) |
f8994aee MD |
542 | return; |
543 | dbg_printf("add set global %lu\n", count); | |
4105056a | 544 | cds_lfht_resize_lazy_count(ht, size, |
6ea6bc67 | 545 | count >> (CHAIN_LEN_TARGET - 1)); |
df44348d MD |
546 | } |
547 | } | |
548 | } | |
549 | ||
550 | static | |
4105056a | 551 | void ht_count_remove(struct cds_lfht *ht, unsigned long size) |
df44348d MD |
552 | { |
553 | unsigned long percpu_count; | |
3171717f | 554 | int cpu; |
df44348d | 555 | |
3171717f MD |
556 | if (unlikely(!ht->percpu_count)) |
557 | return; | |
558 | cpu = ht_get_cpu(); | |
559 | if (unlikely(cpu < 0)) | |
560 | return; | |
561 | percpu_count = uatomic_add_return(&ht->percpu_count[cpu].remove, -1); | |
df44348d MD |
562 | if (unlikely(!(percpu_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) { |
563 | unsigned long count; | |
564 | ||
565 | dbg_printf("remove percpu %lu\n", percpu_count); | |
566 | count = uatomic_add_return(&ht->count, | |
3171717f | 567 | -(1UL << COUNT_COMMIT_ORDER)); |
df44348d MD |
568 | /* If power of 2 */ |
569 | if (!(count & (count - 1))) { | |
4105056a | 570 | if ((count >> CHAIN_LEN_RESIZE_THRESHOLD) >= size) |
f8994aee MD |
571 | return; |
572 | dbg_printf("remove set global %lu\n", count); | |
4105056a | 573 | cds_lfht_resize_lazy_count(ht, size, |
6ea6bc67 | 574 | count >> (CHAIN_LEN_TARGET - 1)); |
df44348d MD |
575 | } |
576 | } | |
577 | } | |
578 | ||
579 | #else /* #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */ | |
580 | ||
581 | static const long nr_cpus_mask = -1; | |
582 | ||
583 | static | |
584 | struct ht_items_count *alloc_per_cpu_items_count(void) | |
585 | { | |
586 | return NULL; | |
587 | } | |
588 | ||
589 | static | |
590 | void free_per_cpu_items_count(struct ht_items_count *count) | |
591 | { | |
592 | } | |
593 | ||
594 | static | |
4105056a | 595 | void ht_count_add(struct cds_lfht *ht, unsigned long size) |
df44348d MD |
596 | { |
597 | } | |
598 | ||
599 | static | |
4105056a | 600 | void ht_count_remove(struct cds_lfht *ht, unsigned long size) |
df44348d MD |
601 | { |
602 | } | |
603 | ||
604 | #endif /* #else #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */ | |
605 | ||
606 | ||
f9830efd | 607 | static |
4105056a | 608 | void check_resize(struct cds_lfht *ht, unsigned long size, uint32_t chain_len) |
f9830efd | 609 | { |
f8994aee MD |
610 | unsigned long count; |
611 | ||
b8af5011 MD |
612 | if (!(ht->flags & CDS_LFHT_AUTO_RESIZE)) |
613 | return; | |
f8994aee MD |
614 | count = uatomic_read(&ht->count); |
615 | /* | |
616 | * Use bucket-local length for small table expand and for | |
617 | * environments lacking per-cpu data support. | |
618 | */ | |
619 | if (count >= (1UL << COUNT_COMMIT_ORDER)) | |
620 | return; | |
24365af7 | 621 | if (chain_len > 100) |
f0c29ed7 | 622 | dbg_printf("WARNING: large chain length: %u.\n", |
24365af7 | 623 | chain_len); |
3390d470 | 624 | if (chain_len >= CHAIN_LEN_RESIZE_THRESHOLD) |
4105056a | 625 | cds_lfht_resize_lazy(ht, size, |
01370f0b | 626 | get_count_order_u32(chain_len - (CHAIN_LEN_TARGET - 1))); |
f9830efd MD |
627 | } |
628 | ||
abc490a1 | 629 | static |
14044b37 | 630 | struct cds_lfht_node *clear_flag(struct cds_lfht_node *node) |
abc490a1 | 631 | { |
14044b37 | 632 | return (struct cds_lfht_node *) (((unsigned long) node) & ~FLAGS_MASK); |
abc490a1 MD |
633 | } |
634 | ||
635 | static | |
14044b37 | 636 | int is_removed(struct cds_lfht_node *node) |
abc490a1 | 637 | { |
d37166c6 | 638 | return ((unsigned long) node) & REMOVED_FLAG; |
abc490a1 MD |
639 | } |
640 | ||
641 | static | |
14044b37 | 642 | struct cds_lfht_node *flag_removed(struct cds_lfht_node *node) |
abc490a1 | 643 | { |
14044b37 | 644 | return (struct cds_lfht_node *) (((unsigned long) node) | REMOVED_FLAG); |
abc490a1 MD |
645 | } |
646 | ||
f5596c94 | 647 | static |
14044b37 | 648 | int is_dummy(struct cds_lfht_node *node) |
f5596c94 MD |
649 | { |
650 | return ((unsigned long) node) & DUMMY_FLAG; | |
651 | } | |
652 | ||
653 | static | |
14044b37 | 654 | struct cds_lfht_node *flag_dummy(struct cds_lfht_node *node) |
f5596c94 | 655 | { |
14044b37 | 656 | return (struct cds_lfht_node *) (((unsigned long) node) | DUMMY_FLAG); |
f5596c94 | 657 | } |
bb7b2f26 MD |
658 | |
659 | static | |
660 | struct cds_lfht_node *get_end(void) | |
661 | { | |
662 | return (struct cds_lfht_node *) END_VALUE; | |
663 | } | |
664 | ||
665 | static | |
666 | int is_end(struct cds_lfht_node *node) | |
667 | { | |
668 | return clear_flag(node) == (struct cds_lfht_node *) END_VALUE; | |
669 | } | |
670 | ||
abc490a1 | 671 | static |
f9830efd | 672 | unsigned long _uatomic_max(unsigned long *ptr, unsigned long v) |
abc490a1 MD |
673 | { |
674 | unsigned long old1, old2; | |
675 | ||
676 | old1 = uatomic_read(ptr); | |
677 | do { | |
678 | old2 = old1; | |
679 | if (old2 >= v) | |
f9830efd | 680 | return old2; |
abc490a1 | 681 | } while ((old1 = uatomic_cmpxchg(ptr, old2, v)) != old2); |
f9830efd | 682 | return v; |
abc490a1 MD |
683 | } |
684 | ||
1475579c MD |
685 | static |
686 | void cds_lfht_free_level(struct rcu_head *head) | |
687 | { | |
688 | struct rcu_level *l = | |
689 | caa_container_of(head, struct rcu_level, head); | |
98808fb1 | 690 | poison_free(l); |
1475579c MD |
691 | } |
692 | ||
273399de MD |
693 | /* |
694 | * Remove all logically deleted nodes from a bucket up to a certain node key. | |
695 | */ | |
696 | static | |
f9c80341 | 697 | void _cds_lfht_gc_bucket(struct cds_lfht_node *dummy, struct cds_lfht_node *node) |
273399de | 698 | { |
14044b37 | 699 | struct cds_lfht_node *iter_prev, *iter, *next, *new_next; |
273399de | 700 | |
c90201ac MD |
701 | assert(!is_dummy(dummy)); |
702 | assert(!is_removed(dummy)); | |
703 | assert(!is_dummy(node)); | |
704 | assert(!is_removed(node)); | |
273399de MD |
705 | for (;;) { |
706 | iter_prev = dummy; | |
707 | /* We can always skip the dummy node initially */ | |
cc4fcb10 MD |
708 | iter = rcu_dereference(iter_prev->p.next); |
709 | assert(iter_prev->p.reverse_hash <= node->p.reverse_hash); | |
bd4db153 MD |
710 | /* |
711 | * We should never be called with dummy (start of chain) | |
712 | * and logically removed node (end of path compression | |
713 | * marker) being the actual same node. This would be a | |
714 | * bug in the algorithm implementation. | |
715 | */ | |
716 | assert(dummy != node); | |
273399de | 717 | for (;;) { |
bb7b2f26 | 718 | if (unlikely(is_end(iter))) |
f9c80341 | 719 | return; |
76412f24 | 720 | if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash)) |
f9c80341 | 721 | return; |
cc4fcb10 | 722 | next = rcu_dereference(clear_flag(iter)->p.next); |
76412f24 | 723 | if (likely(is_removed(next))) |
273399de | 724 | break; |
b453eae1 | 725 | iter_prev = clear_flag(iter); |
273399de MD |
726 | iter = next; |
727 | } | |
728 | assert(!is_removed(iter)); | |
f5596c94 MD |
729 | if (is_dummy(iter)) |
730 | new_next = flag_dummy(clear_flag(next)); | |
731 | else | |
732 | new_next = clear_flag(next); | |
733 | (void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next); | |
273399de | 734 | } |
f9c80341 | 735 | return; |
273399de MD |
736 | } |
737 | ||
abc490a1 | 738 | static |
4105056a MD |
739 | struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht, |
740 | unsigned long size, | |
741 | struct cds_lfht_node *node, | |
742 | int unique, int dummy) | |
abc490a1 | 743 | { |
14044b37 | 744 | struct cds_lfht_node *iter_prev, *iter, *next, *new_node, *new_next, |
f5596c94 | 745 | *dummy_node; |
14044b37 | 746 | struct _cds_lfht_node *lookup; |
24365af7 | 747 | unsigned long hash, index, order; |
abc490a1 | 748 | |
c90201ac MD |
749 | assert(!is_dummy(node)); |
750 | assert(!is_removed(node)); | |
4105056a | 751 | if (!size) { |
f5596c94 | 752 | assert(dummy); |
bb7b2f26 | 753 | node->p.next = flag_dummy(get_end()); |
18117871 MD |
754 | return node; /* Initial first add (head) */ |
755 | } | |
cc4fcb10 | 756 | hash = bit_reverse_ulong(node->p.reverse_hash); |
abc490a1 | 757 | for (;;) { |
f9830efd | 758 | uint32_t chain_len = 0; |
abc490a1 | 759 | |
11519af6 MD |
760 | /* |
761 | * iter_prev points to the non-removed node prior to the | |
762 | * insert location. | |
11519af6 | 763 | */ |
4105056a | 764 | index = hash & (size - 1); |
24365af7 | 765 | order = get_count_order_ulong(index + 1); |
4105056a | 766 | lookup = &ht->t.tbl[order]->nodes[index & ((!order ? 0 : (1UL << (order - 1))) - 1)]; |
14044b37 | 767 | iter_prev = (struct cds_lfht_node *) lookup; |
11519af6 | 768 | /* We can always skip the dummy node initially */ |
cc4fcb10 MD |
769 | iter = rcu_dereference(iter_prev->p.next); |
770 | assert(iter_prev->p.reverse_hash <= node->p.reverse_hash); | |
abc490a1 | 771 | for (;;) { |
bb7b2f26 | 772 | if (unlikely(is_end(iter))) |
273399de | 773 | goto insert; |
76412f24 | 774 | if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash)) |
273399de | 775 | goto insert; |
cc4fcb10 | 776 | next = rcu_dereference(clear_flag(iter)->p.next); |
76412f24 | 777 | if (unlikely(is_removed(next))) |
9dba85be | 778 | goto gc_node; |
e43f23f8 | 779 | if (unique |
1b81fe1a | 780 | && !is_dummy(next) |
e43f23f8 MD |
781 | && !ht->compare_fct(node->key, node->key_len, |
782 | clear_flag(iter)->key, | |
783 | clear_flag(iter)->key_len)) | |
18117871 | 784 | return clear_flag(iter); |
11519af6 | 785 | /* Only account for identical reverse hash once */ |
24365af7 MD |
786 | if (iter_prev->p.reverse_hash != clear_flag(iter)->p.reverse_hash |
787 | && !is_dummy(next)) | |
4105056a | 788 | check_resize(ht, size, ++chain_len); |
11519af6 | 789 | iter_prev = clear_flag(iter); |
273399de | 790 | iter = next; |
abc490a1 | 791 | } |
273399de | 792 | insert: |
7ec59d3b | 793 | assert(node != clear_flag(iter)); |
11519af6 | 794 | assert(!is_removed(iter_prev)); |
c90201ac | 795 | assert(!is_removed(iter)); |
f000907d | 796 | assert(iter_prev != node); |
f9c80341 | 797 | if (!dummy) |
1b81fe1a | 798 | node->p.next = clear_flag(iter); |
f9c80341 MD |
799 | else |
800 | node->p.next = flag_dummy(clear_flag(iter)); | |
f5596c94 MD |
801 | if (is_dummy(iter)) |
802 | new_node = flag_dummy(node); | |
803 | else | |
804 | new_node = node; | |
cc4fcb10 | 805 | if (uatomic_cmpxchg(&iter_prev->p.next, iter, |
f5596c94 | 806 | new_node) != iter) |
273399de | 807 | continue; /* retry */ |
11519af6 | 808 | else |
273399de | 809 | goto gc_end; |
9dba85be MD |
810 | gc_node: |
811 | assert(!is_removed(iter)); | |
f5596c94 MD |
812 | if (is_dummy(iter)) |
813 | new_next = flag_dummy(clear_flag(next)); | |
814 | else | |
815 | new_next = clear_flag(next); | |
816 | (void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next); | |
273399de | 817 | /* retry */ |
464a1ec9 | 818 | } |
273399de MD |
819 | gc_end: |
820 | /* Garbage collect logically removed nodes in the bucket */ | |
4105056a | 821 | index = hash & (size - 1); |
24365af7 | 822 | order = get_count_order_ulong(index + 1); |
4105056a | 823 | lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1)) - 1))]; |
14044b37 | 824 | dummy_node = (struct cds_lfht_node *) lookup; |
f9c80341 | 825 | _cds_lfht_gc_bucket(dummy_node, node); |
18117871 | 826 | return node; |
abc490a1 | 827 | } |
464a1ec9 | 828 | |
abc490a1 | 829 | static |
4105056a MD |
830 | int _cds_lfht_remove(struct cds_lfht *ht, unsigned long size, |
831 | struct cds_lfht_node *node, | |
832 | int dummy_removal) | |
abc490a1 | 833 | { |
14044b37 MD |
834 | struct cds_lfht_node *dummy, *next, *old; |
835 | struct _cds_lfht_node *lookup; | |
abc490a1 | 836 | int flagged = 0; |
24365af7 | 837 | unsigned long hash, index, order; |
5e28c532 | 838 | |
7ec59d3b | 839 | /* logically delete the node */ |
c90201ac MD |
840 | assert(!is_dummy(node)); |
841 | assert(!is_removed(node)); | |
cc4fcb10 | 842 | old = rcu_dereference(node->p.next); |
7ec59d3b MD |
843 | do { |
844 | next = old; | |
76412f24 | 845 | if (unlikely(is_removed(next))) |
7ec59d3b | 846 | goto end; |
1475579c MD |
847 | if (dummy_removal) |
848 | assert(is_dummy(next)); | |
849 | else | |
850 | assert(!is_dummy(next)); | |
cc4fcb10 | 851 | old = uatomic_cmpxchg(&node->p.next, next, |
7ec59d3b MD |
852 | flag_removed(next)); |
853 | } while (old != next); | |
854 | ||
855 | /* We performed the (logical) deletion. */ | |
856 | flagged = 1; | |
857 | ||
858 | /* | |
859 | * Ensure that the node is not visible to readers anymore: lookup for | |
273399de MD |
860 | * the node, and remove it (along with any other logically removed node) |
861 | * if found. | |
11519af6 | 862 | */ |
cc4fcb10 | 863 | hash = bit_reverse_ulong(node->p.reverse_hash); |
4105056a MD |
864 | assert(size > 0); |
865 | index = hash & (size - 1); | |
24365af7 | 866 | order = get_count_order_ulong(index + 1); |
4105056a | 867 | lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1)) - 1))]; |
14044b37 | 868 | dummy = (struct cds_lfht_node *) lookup; |
f9c80341 | 869 | _cds_lfht_gc_bucket(dummy, node); |
2ed95849 | 870 | end: |
11519af6 MD |
871 | /* |
872 | * Only the flagging action indicated that we (and no other) | |
873 | * removed the node from the hash. | |
874 | */ | |
7ec59d3b | 875 | if (flagged) { |
cc4fcb10 | 876 | assert(is_removed(rcu_dereference(node->p.next))); |
11519af6 | 877 | return 0; |
7ec59d3b | 878 | } else |
11519af6 | 879 | return -ENOENT; |
abc490a1 | 880 | } |
2ed95849 | 881 | |
e8de508e MD |
882 | /* |
883 | * Holding RCU read lock to protect _cds_lfht_add against memory | |
884 | * reclaim that could be performed by other call_rcu worker threads (ABA | |
885 | * problem). | |
9ee0fc9a MD |
886 | * |
887 | * TODO: when we reach a certain length, we can split this population phase over | |
888 | * many worker threads, based on the number of CPUs available in the system. | |
889 | * This should therefore take care of not having the expand lagging behind too | |
890 | * many concurrent insertion threads by using the scheduler's ability to | |
891 | * schedule dummy node population fairly with insertions. | |
e8de508e | 892 | */ |
4105056a | 893 | static |
dc1da8f6 | 894 | void init_table_populate(struct cds_lfht *ht, unsigned long i, unsigned long len) |
4105056a MD |
895 | { |
896 | unsigned long j; | |
897 | ||
5f511391 | 898 | ht->cds_lfht_rcu_thread_online(); |
4105056a MD |
899 | ht->cds_lfht_rcu_read_lock(); |
900 | for (j = 0; j < len; j++) { | |
901 | struct cds_lfht_node *new_node = | |
902 | (struct cds_lfht_node *) &ht->t.tbl[i]->nodes[j]; | |
903 | ||
dc1da8f6 | 904 | dbg_printf("init populate: i %lu j %lu hash %lu\n", |
4105056a | 905 | i, j, !i ? 0 : (1UL << (i - 1)) + j); |
dc1da8f6 MD |
906 | new_node->p.reverse_hash = |
907 | bit_reverse_ulong(!i ? 0 : (1UL << (i - 1)) + j); | |
4105056a MD |
908 | (void) _cds_lfht_add(ht, !i ? 0 : (1UL << (i - 1)), |
909 | new_node, 0, 1); | |
910 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) | |
911 | break; | |
912 | } | |
913 | ht->cds_lfht_rcu_read_unlock(); | |
5f511391 | 914 | ht->cds_lfht_rcu_thread_offline(); |
4105056a MD |
915 | } |
916 | ||
abc490a1 | 917 | static |
4105056a | 918 | void init_table(struct cds_lfht *ht, |
24365af7 MD |
919 | unsigned long first_order, unsigned long len_order) |
920 | { | |
921 | unsigned long i, end_order; | |
922 | ||
f0c29ed7 | 923 | dbg_printf("init table: first_order %lu end_order %lu\n", |
24365af7 MD |
924 | first_order, first_order + len_order); |
925 | end_order = first_order + len_order; | |
24365af7 | 926 | for (i = first_order; i < end_order; i++) { |
4105056a | 927 | unsigned long len; |
24365af7 MD |
928 | |
929 | len = !i ? 1 : 1UL << (i - 1); | |
f0c29ed7 | 930 | dbg_printf("init order %lu len: %lu\n", i, len); |
4d676753 MD |
931 | |
932 | /* Stop expand if the resize target changes under us */ | |
933 | if (CMM_LOAD_SHARED(ht->t.resize_target) < (!i ? 1 : (1UL << i))) | |
934 | break; | |
935 | ||
4105056a | 936 | ht->t.tbl[i] = calloc(1, sizeof(struct rcu_level) |
1475579c | 937 | + (len * sizeof(struct _cds_lfht_node))); |
4105056a | 938 | |
4105056a | 939 | /* |
dc1da8f6 MD |
940 | * Set all dummy nodes reverse hash values for a level and |
941 | * link all dummy nodes into the table. | |
4105056a | 942 | */ |
dc1da8f6 | 943 | init_table_populate(ht, i, len); |
4105056a | 944 | |
f9c80341 MD |
945 | /* |
946 | * Update table size. | |
947 | */ | |
948 | cmm_smp_wmb(); /* populate data before RCU size */ | |
949 | CMM_STORE_SHARED(ht->t.size, !i ? 1 : (1UL << i)); | |
950 | ||
4105056a MD |
951 | dbg_printf("init new size: %lu\n", !i ? 1 : (1UL << i)); |
952 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) | |
953 | break; | |
954 | } | |
955 | } | |
956 | ||
e8de508e MD |
957 | /* |
958 | * Holding RCU read lock to protect _cds_lfht_remove against memory | |
959 | * reclaim that could be performed by other call_rcu worker threads (ABA | |
960 | * problem). | |
961 | * For a single level, we logically remove and garbage collect each node. | |
962 | * | |
963 | * As a design choice, we perform logical removal and garbage collection on a | |
964 | * node-per-node basis to simplify this algorithm. We also assume keeping good | |
965 | * cache locality of the operation would overweight possible performance gain | |
966 | * that could be achieved by batching garbage collection for multiple levels. | |
967 | * However, this would have to be justified by benchmarks. | |
968 | * | |
969 | * Concurrent removal and add operations are helping us perform garbage | |
970 | * collection of logically removed nodes. We guarantee that all logically | |
971 | * removed nodes have been garbage-collected (unlinked) before call_rcu is | |
972 | * invoked to free a hole level of dummy nodes (after a grace period). | |
973 | * | |
974 | * Logical removal and garbage collection can therefore be done in batch or on a | |
975 | * node-per-node basis, as long as the guarantee above holds. | |
9ee0fc9a MD |
976 | * |
977 | * TODO: when we reach a certain length, we can split this removal over many | |
978 | * worker threads, based on the number of CPUs available in the system. This | |
979 | * should take care of not letting resize process lag behind too many concurrent | |
980 | * updater threads actively inserting into the hash table. | |
e8de508e | 981 | */ |
4105056a MD |
982 | static |
983 | void remove_table(struct cds_lfht *ht, unsigned long i, unsigned long len) | |
984 | { | |
985 | unsigned long j; | |
986 | ||
5f511391 | 987 | ht->cds_lfht_rcu_thread_online(); |
4105056a MD |
988 | ht->cds_lfht_rcu_read_lock(); |
989 | for (j = 0; j < len; j++) { | |
990 | struct cds_lfht_node *fini_node = | |
991 | (struct cds_lfht_node *) &ht->t.tbl[i]->nodes[j]; | |
992 | ||
993 | dbg_printf("remove entry: i %lu j %lu hash %lu\n", | |
994 | i, j, !i ? 0 : (1UL << (i - 1)) + j); | |
995 | fini_node->p.reverse_hash = | |
996 | bit_reverse_ulong(!i ? 0 : (1UL << (i - 1)) + j); | |
997 | (void) _cds_lfht_remove(ht, !i ? 0 : (1UL << (i - 1)), | |
998 | fini_node, 1); | |
33c7c748 MD |
999 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) |
1000 | break; | |
abc490a1 | 1001 | } |
4105056a | 1002 | ht->cds_lfht_rcu_read_unlock(); |
5f511391 | 1003 | ht->cds_lfht_rcu_thread_offline(); |
2ed95849 MD |
1004 | } |
1005 | ||
1475579c | 1006 | static |
4105056a | 1007 | void fini_table(struct cds_lfht *ht, |
1475579c MD |
1008 | unsigned long first_order, unsigned long len_order) |
1009 | { | |
1010 | long i, end_order; | |
1011 | ||
1012 | dbg_printf("fini table: first_order %lu end_order %lu\n", | |
1013 | first_order, first_order + len_order); | |
1014 | end_order = first_order + len_order; | |
1015 | assert(first_order > 0); | |
1475579c | 1016 | for (i = end_order - 1; i >= first_order; i--) { |
4105056a | 1017 | unsigned long len; |
1475579c MD |
1018 | |
1019 | len = !i ? 1 : 1UL << (i - 1); | |
1020 | dbg_printf("fini order %lu len: %lu\n", i, len); | |
4105056a | 1021 | |
4d676753 MD |
1022 | /* Stop shrink if the resize target changes under us */ |
1023 | if (CMM_LOAD_SHARED(ht->t.resize_target) > (1UL << (i - 1))) | |
1024 | break; | |
1025 | ||
1026 | cmm_smp_wmb(); /* populate data before RCU size */ | |
1027 | CMM_STORE_SHARED(ht->t.size, 1UL << (i - 1)); | |
1028 | ||
1029 | /* | |
1030 | * We need to wait for all add operations to reach Q.S. (and | |
1031 | * thus use the new table for lookups) before we can start | |
1032 | * releasing the old dummy nodes. Otherwise their lookup will | |
1033 | * return a logically removed node as insert position. | |
1034 | */ | |
1035 | ht->cds_lfht_synchronize_rcu(); | |
1036 | ||
21263e21 | 1037 | /* |
4105056a MD |
1038 | * Set "removed" flag in dummy nodes about to be removed. |
1039 | * Unlink all now-logically-removed dummy node pointers. | |
1040 | * Concurrent add/remove operation are helping us doing | |
1041 | * the gc. | |
21263e21 | 1042 | */ |
4105056a MD |
1043 | remove_table(ht, i, len); |
1044 | ||
1045 | ht->cds_lfht_call_rcu(&ht->t.tbl[i]->head, cds_lfht_free_level); | |
1046 | ||
1047 | dbg_printf("fini new size: %lu\n", 1UL << i); | |
1475579c MD |
1048 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) |
1049 | break; | |
1050 | } | |
1475579c MD |
1051 | } |
1052 | ||
7a9dcf9b | 1053 | struct cds_lfht *_cds_lfht_new(cds_lfht_hash_fct hash_fct, |
14044b37 MD |
1054 | cds_lfht_compare_fct compare_fct, |
1055 | unsigned long hash_seed, | |
1056 | unsigned long init_size, | |
b8af5011 | 1057 | int flags, |
14044b37 | 1058 | void (*cds_lfht_call_rcu)(struct rcu_head *head, |
1475579c | 1059 | void (*func)(struct rcu_head *head)), |
01dbfa62 MD |
1060 | void (*cds_lfht_synchronize_rcu)(void), |
1061 | void (*cds_lfht_rcu_read_lock)(void), | |
5f511391 MD |
1062 | void (*cds_lfht_rcu_read_unlock)(void), |
1063 | void (*cds_lfht_rcu_thread_offline)(void), | |
1064 | void (*cds_lfht_rcu_thread_online)(void)) | |
abc490a1 | 1065 | { |
14044b37 | 1066 | struct cds_lfht *ht; |
24365af7 | 1067 | unsigned long order; |
abc490a1 | 1068 | |
8129be4e | 1069 | /* init_size must be power of two */ |
49619ea0 | 1070 | if (init_size && (init_size & (init_size - 1))) |
8129be4e | 1071 | return NULL; |
14044b37 | 1072 | ht = calloc(1, sizeof(struct cds_lfht)); |
abc490a1 | 1073 | ht->hash_fct = hash_fct; |
732ad076 MD |
1074 | ht->compare_fct = compare_fct; |
1075 | ht->hash_seed = hash_seed; | |
14044b37 | 1076 | ht->cds_lfht_call_rcu = cds_lfht_call_rcu; |
1475579c | 1077 | ht->cds_lfht_synchronize_rcu = cds_lfht_synchronize_rcu; |
01dbfa62 MD |
1078 | ht->cds_lfht_rcu_read_lock = cds_lfht_rcu_read_lock; |
1079 | ht->cds_lfht_rcu_read_unlock = cds_lfht_rcu_read_unlock; | |
5f511391 MD |
1080 | ht->cds_lfht_rcu_thread_offline = cds_lfht_rcu_thread_offline; |
1081 | ht->cds_lfht_rcu_thread_online = cds_lfht_rcu_thread_online; | |
df44348d | 1082 | ht->percpu_count = alloc_per_cpu_items_count(); |
abc490a1 MD |
1083 | /* this mutex should not nest in read-side C.S. */ |
1084 | pthread_mutex_init(&ht->resize_mutex, NULL); | |
cd95516d | 1085 | order = get_count_order_ulong(max(init_size, MIN_TABLE_SIZE)) + 1; |
b8af5011 | 1086 | ht->flags = flags; |
5f511391 | 1087 | ht->cds_lfht_rcu_thread_offline(); |
f000907d | 1088 | pthread_mutex_lock(&ht->resize_mutex); |
4d676753 | 1089 | ht->t.resize_target = 1UL << (order - 1); |
4105056a | 1090 | init_table(ht, 0, order); |
f000907d | 1091 | pthread_mutex_unlock(&ht->resize_mutex); |
5f511391 | 1092 | ht->cds_lfht_rcu_thread_online(); |
abc490a1 MD |
1093 | return ht; |
1094 | } | |
1095 | ||
14044b37 | 1096 | struct cds_lfht_node *cds_lfht_lookup(struct cds_lfht *ht, void *key, size_t key_len) |
2ed95849 | 1097 | { |
bb7b2f26 | 1098 | struct cds_lfht_node *node, *next, *dummy_node; |
14044b37 | 1099 | struct _cds_lfht_node *lookup; |
4105056a | 1100 | unsigned long hash, reverse_hash, index, order, size; |
2ed95849 | 1101 | |
732ad076 | 1102 | hash = ht->hash_fct(key, key_len, ht->hash_seed); |
abc490a1 | 1103 | reverse_hash = bit_reverse_ulong(hash); |
464a1ec9 | 1104 | |
4105056a MD |
1105 | size = rcu_dereference(ht->t.size); |
1106 | index = hash & (size - 1); | |
24365af7 | 1107 | order = get_count_order_ulong(index + 1); |
4105056a | 1108 | lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1))) - 1)]; |
f0c29ed7 | 1109 | dbg_printf("lookup hash %lu index %lu order %lu aridx %lu\n", |
554c284e | 1110 | hash, index, order, index & (!order ? 0 : ((1UL << (order - 1)) - 1))); |
bb7b2f26 MD |
1111 | dummy_node = (struct cds_lfht_node *) lookup; |
1112 | /* We can always skip the dummy node initially */ | |
1113 | node = rcu_dereference(dummy_node->p.next); | |
bb7b2f26 | 1114 | node = clear_flag(node); |
2ed95849 | 1115 | for (;;) { |
bb7b2f26 MD |
1116 | if (unlikely(is_end(node))) { |
1117 | node = NULL; | |
abc490a1 | 1118 | break; |
bb7b2f26 | 1119 | } |
cc4fcb10 | 1120 | if (unlikely(node->p.reverse_hash > reverse_hash)) { |
abc490a1 MD |
1121 | node = NULL; |
1122 | break; | |
2ed95849 | 1123 | } |
1b81fe1a MD |
1124 | next = rcu_dereference(node->p.next); |
1125 | if (likely(!is_removed(next)) | |
1126 | && !is_dummy(next) | |
49c2e2d6 | 1127 | && likely(!ht->compare_fct(node->key, node->key_len, key, key_len))) { |
273399de | 1128 | break; |
2ed95849 | 1129 | } |
1b81fe1a | 1130 | node = clear_flag(next); |
2ed95849 | 1131 | } |
1b81fe1a | 1132 | assert(!node || !is_dummy(rcu_dereference(node->p.next))); |
abc490a1 MD |
1133 | return node; |
1134 | } | |
e0ba718a | 1135 | |
a481e5ff MD |
1136 | struct cds_lfht_node *cds_lfht_next(struct cds_lfht *ht, |
1137 | struct cds_lfht_node *node) | |
1138 | { | |
1139 | struct cds_lfht_node *next; | |
1140 | unsigned long reverse_hash; | |
1141 | void *key; | |
1142 | size_t key_len; | |
1143 | ||
1144 | reverse_hash = node->p.reverse_hash; | |
1145 | key = node->key; | |
1146 | key_len = node->key_len; | |
1147 | next = rcu_dereference(node->p.next); | |
1148 | node = clear_flag(next); | |
1149 | ||
1150 | for (;;) { | |
bb7b2f26 MD |
1151 | if (unlikely(is_end(node))) { |
1152 | node = NULL; | |
a481e5ff | 1153 | break; |
bb7b2f26 | 1154 | } |
a481e5ff MD |
1155 | if (unlikely(node->p.reverse_hash > reverse_hash)) { |
1156 | node = NULL; | |
1157 | break; | |
1158 | } | |
1159 | next = rcu_dereference(node->p.next); | |
1160 | if (likely(!is_removed(next)) | |
1161 | && !is_dummy(next) | |
1162 | && likely(!ht->compare_fct(node->key, node->key_len, key, key_len))) { | |
1163 | break; | |
1164 | } | |
1165 | node = clear_flag(next); | |
1166 | } | |
1167 | assert(!node || !is_dummy(rcu_dereference(node->p.next))); | |
1168 | return node; | |
1169 | } | |
1170 | ||
14044b37 | 1171 | void cds_lfht_add(struct cds_lfht *ht, struct cds_lfht_node *node) |
abc490a1 | 1172 | { |
4105056a | 1173 | unsigned long hash, size; |
ab7d5fc6 | 1174 | |
49c2e2d6 | 1175 | hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed); |
cc4fcb10 | 1176 | node->p.reverse_hash = bit_reverse_ulong((unsigned long) hash); |
2ed95849 | 1177 | |
4105056a MD |
1178 | size = rcu_dereference(ht->t.size); |
1179 | (void) _cds_lfht_add(ht, size, node, 0, 0); | |
1180 | ht_count_add(ht, size); | |
3eca1b8c MD |
1181 | } |
1182 | ||
14044b37 MD |
1183 | struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht, |
1184 | struct cds_lfht_node *node) | |
3eca1b8c | 1185 | { |
4105056a | 1186 | unsigned long hash, size; |
df44348d | 1187 | struct cds_lfht_node *ret; |
3eca1b8c | 1188 | |
49c2e2d6 | 1189 | hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed); |
cc4fcb10 | 1190 | node->p.reverse_hash = bit_reverse_ulong((unsigned long) hash); |
3eca1b8c | 1191 | |
4105056a MD |
1192 | size = rcu_dereference(ht->t.size); |
1193 | ret = _cds_lfht_add(ht, size, node, 1, 0); | |
17f31d1b | 1194 | if (ret == node) |
4105056a | 1195 | ht_count_add(ht, size); |
df44348d | 1196 | return ret; |
2ed95849 MD |
1197 | } |
1198 | ||
14044b37 | 1199 | int cds_lfht_remove(struct cds_lfht *ht, struct cds_lfht_node *node) |
2ed95849 | 1200 | { |
4105056a | 1201 | unsigned long size; |
df44348d | 1202 | int ret; |
abc490a1 | 1203 | |
4105056a MD |
1204 | size = rcu_dereference(ht->t.size); |
1205 | ret = _cds_lfht_remove(ht, size, node, 0); | |
df44348d | 1206 | if (!ret) |
4105056a | 1207 | ht_count_remove(ht, size); |
df44348d | 1208 | return ret; |
2ed95849 | 1209 | } |
ab7d5fc6 | 1210 | |
abc490a1 | 1211 | static |
14044b37 | 1212 | int cds_lfht_delete_dummy(struct cds_lfht *ht) |
674f7a69 | 1213 | { |
14044b37 MD |
1214 | struct cds_lfht_node *node; |
1215 | struct _cds_lfht_node *lookup; | |
4105056a | 1216 | unsigned long order, i, size; |
674f7a69 | 1217 | |
abc490a1 | 1218 | /* Check that the table is empty */ |
4105056a | 1219 | lookup = &ht->t.tbl[0]->nodes[0]; |
14044b37 | 1220 | node = (struct cds_lfht_node *) lookup; |
abc490a1 | 1221 | do { |
1b81fe1a MD |
1222 | node = clear_flag(node)->p.next; |
1223 | if (!is_dummy(node)) | |
abc490a1 | 1224 | return -EPERM; |
273399de | 1225 | assert(!is_removed(node)); |
bb7b2f26 | 1226 | } while (!is_end(node)); |
4105056a MD |
1227 | /* |
1228 | * size accessed without rcu_dereference because hash table is | |
1229 | * being destroyed. | |
1230 | */ | |
1231 | size = ht->t.size; | |
abc490a1 | 1232 | /* Internal sanity check: all nodes left should be dummy */ |
4105056a | 1233 | for (order = 0; order < get_count_order_ulong(size) + 1; order++) { |
24365af7 MD |
1234 | unsigned long len; |
1235 | ||
1236 | len = !order ? 1 : 1UL << (order - 1); | |
1237 | for (i = 0; i < len; i++) { | |
f0c29ed7 | 1238 | dbg_printf("delete order %lu i %lu hash %lu\n", |
24365af7 | 1239 | order, i, |
4105056a MD |
1240 | bit_reverse_ulong(ht->t.tbl[order]->nodes[i].reverse_hash)); |
1241 | assert(is_dummy(ht->t.tbl[order]->nodes[i].next)); | |
24365af7 | 1242 | } |
4105056a | 1243 | poison_free(ht->t.tbl[order]); |
674f7a69 | 1244 | } |
abc490a1 | 1245 | return 0; |
674f7a69 MD |
1246 | } |
1247 | ||
1248 | /* | |
1249 | * Should only be called when no more concurrent readers nor writers can | |
1250 | * possibly access the table. | |
1251 | */ | |
14044b37 | 1252 | int cds_lfht_destroy(struct cds_lfht *ht) |
674f7a69 | 1253 | { |
5e28c532 MD |
1254 | int ret; |
1255 | ||
848d4088 | 1256 | /* Wait for in-flight resize operations to complete */ |
33c7c748 | 1257 | CMM_STORE_SHARED(ht->in_progress_destroy, 1); |
848d4088 MD |
1258 | while (uatomic_read(&ht->in_progress_resize)) |
1259 | poll(NULL, 0, 100); /* wait for 100ms */ | |
14044b37 | 1260 | ret = cds_lfht_delete_dummy(ht); |
abc490a1 MD |
1261 | if (ret) |
1262 | return ret; | |
df44348d | 1263 | free_per_cpu_items_count(ht->percpu_count); |
98808fb1 | 1264 | poison_free(ht); |
5e28c532 | 1265 | return ret; |
674f7a69 MD |
1266 | } |
1267 | ||
14044b37 | 1268 | void cds_lfht_count_nodes(struct cds_lfht *ht, |
273399de MD |
1269 | unsigned long *count, |
1270 | unsigned long *removed) | |
1271 | { | |
14044b37 MD |
1272 | struct cds_lfht_node *node, *next; |
1273 | struct _cds_lfht_node *lookup; | |
24365af7 | 1274 | unsigned long nr_dummy = 0; |
273399de MD |
1275 | |
1276 | *count = 0; | |
1277 | *removed = 0; | |
1278 | ||
24365af7 | 1279 | /* Count non-dummy nodes in the table */ |
4105056a | 1280 | lookup = &ht->t.tbl[0]->nodes[0]; |
14044b37 | 1281 | node = (struct cds_lfht_node *) lookup; |
273399de | 1282 | do { |
cc4fcb10 | 1283 | next = rcu_dereference(node->p.next); |
273399de | 1284 | if (is_removed(next)) { |
1b81fe1a | 1285 | assert(!is_dummy(next)); |
273399de | 1286 | (*removed)++; |
1b81fe1a | 1287 | } else if (!is_dummy(next)) |
273399de | 1288 | (*count)++; |
24365af7 MD |
1289 | else |
1290 | (nr_dummy)++; | |
273399de | 1291 | node = clear_flag(next); |
bb7b2f26 | 1292 | } while (!is_end(node)); |
f0c29ed7 | 1293 | dbg_printf("number of dummy nodes: %lu\n", nr_dummy); |
273399de MD |
1294 | } |
1295 | ||
1475579c | 1296 | /* called with resize mutex held */ |
abc490a1 | 1297 | static |
4105056a | 1298 | void _do_cds_lfht_grow(struct cds_lfht *ht, |
1475579c | 1299 | unsigned long old_size, unsigned long new_size) |
abc490a1 | 1300 | { |
1475579c | 1301 | unsigned long old_order, new_order; |
1475579c MD |
1302 | |
1303 | old_order = get_count_order_ulong(old_size) + 1; | |
1304 | new_order = get_count_order_ulong(new_size) + 1; | |
1305 | printf("resize from %lu (order %lu) to %lu (order %lu) buckets\n", | |
1306 | old_size, old_order, new_size, new_order); | |
1475579c | 1307 | assert(new_size > old_size); |
4105056a | 1308 | init_table(ht, old_order, new_order - old_order); |
abc490a1 MD |
1309 | } |
1310 | ||
1311 | /* called with resize mutex held */ | |
1312 | static | |
4105056a | 1313 | void _do_cds_lfht_shrink(struct cds_lfht *ht, |
1475579c | 1314 | unsigned long old_size, unsigned long new_size) |
464a1ec9 | 1315 | { |
1475579c | 1316 | unsigned long old_order, new_order; |
464a1ec9 | 1317 | |
cd95516d | 1318 | new_size = max(new_size, MIN_TABLE_SIZE); |
24365af7 | 1319 | old_order = get_count_order_ulong(old_size) + 1; |
24365af7 | 1320 | new_order = get_count_order_ulong(new_size) + 1; |
df44348d | 1321 | printf("resize from %lu (order %lu) to %lu (order %lu) buckets\n", |
df03fab8 | 1322 | old_size, old_order, new_size, new_order); |
1475579c | 1323 | assert(new_size < old_size); |
1475579c | 1324 | |
4105056a MD |
1325 | /* Remove and unlink all dummy nodes to remove. */ |
1326 | fini_table(ht, new_order, old_order - new_order); | |
464a1ec9 MD |
1327 | } |
1328 | ||
1475579c MD |
1329 | |
1330 | /* called with resize mutex held */ | |
1331 | static | |
1332 | void _do_cds_lfht_resize(struct cds_lfht *ht) | |
1333 | { | |
1334 | unsigned long new_size, old_size; | |
4105056a MD |
1335 | |
1336 | /* | |
1337 | * Resize table, re-do if the target size has changed under us. | |
1338 | */ | |
1339 | do { | |
1340 | ht->t.resize_initiated = 1; | |
1341 | old_size = ht->t.size; | |
1342 | new_size = CMM_LOAD_SHARED(ht->t.resize_target); | |
1343 | if (old_size < new_size) | |
1344 | _do_cds_lfht_grow(ht, old_size, new_size); | |
1345 | else if (old_size > new_size) | |
1346 | _do_cds_lfht_shrink(ht, old_size, new_size); | |
1347 | ht->t.resize_initiated = 0; | |
1348 | /* write resize_initiated before read resize_target */ | |
1349 | cmm_smp_mb(); | |
4d676753 | 1350 | } while (ht->t.size != CMM_LOAD_SHARED(ht->t.resize_target)); |
1475579c MD |
1351 | } |
1352 | ||
abc490a1 | 1353 | static |
4105056a | 1354 | unsigned long resize_target_update(struct cds_lfht *ht, unsigned long size, |
f9830efd | 1355 | int growth_order) |
464a1ec9 | 1356 | { |
4105056a MD |
1357 | return _uatomic_max(&ht->t.resize_target, |
1358 | size << growth_order); | |
464a1ec9 MD |
1359 | } |
1360 | ||
1475579c | 1361 | static |
4105056a | 1362 | void resize_target_update_count(struct cds_lfht *ht, |
b8af5011 | 1363 | unsigned long count) |
1475579c | 1364 | { |
cd95516d | 1365 | count = max(count, MIN_TABLE_SIZE); |
4105056a | 1366 | uatomic_set(&ht->t.resize_target, count); |
1475579c MD |
1367 | } |
1368 | ||
1369 | void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size) | |
464a1ec9 | 1370 | { |
4105056a MD |
1371 | resize_target_update_count(ht, new_size); |
1372 | CMM_STORE_SHARED(ht->t.resize_initiated, 1); | |
5f511391 | 1373 | ht->cds_lfht_rcu_thread_offline(); |
1475579c MD |
1374 | pthread_mutex_lock(&ht->resize_mutex); |
1375 | _do_cds_lfht_resize(ht); | |
1376 | pthread_mutex_unlock(&ht->resize_mutex); | |
5f511391 | 1377 | ht->cds_lfht_rcu_thread_online(); |
abc490a1 | 1378 | } |
464a1ec9 | 1379 | |
abc490a1 MD |
1380 | static |
1381 | void do_resize_cb(struct rcu_head *head) | |
1382 | { | |
1383 | struct rcu_resize_work *work = | |
1384 | caa_container_of(head, struct rcu_resize_work, head); | |
14044b37 | 1385 | struct cds_lfht *ht = work->ht; |
abc490a1 | 1386 | |
5f511391 | 1387 | ht->cds_lfht_rcu_thread_offline(); |
abc490a1 | 1388 | pthread_mutex_lock(&ht->resize_mutex); |
14044b37 | 1389 | _do_cds_lfht_resize(ht); |
abc490a1 | 1390 | pthread_mutex_unlock(&ht->resize_mutex); |
5f511391 | 1391 | ht->cds_lfht_rcu_thread_online(); |
98808fb1 | 1392 | poison_free(work); |
848d4088 MD |
1393 | cmm_smp_mb(); /* finish resize before decrement */ |
1394 | uatomic_dec(&ht->in_progress_resize); | |
464a1ec9 MD |
1395 | } |
1396 | ||
abc490a1 | 1397 | static |
4105056a | 1398 | void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth) |
ab7d5fc6 | 1399 | { |
abc490a1 | 1400 | struct rcu_resize_work *work; |
f9830efd | 1401 | unsigned long target_size; |
abc490a1 | 1402 | |
4105056a MD |
1403 | target_size = resize_target_update(ht, size, growth); |
1404 | /* Store resize_target before read resize_initiated */ | |
1405 | cmm_smp_mb(); | |
1406 | if (!CMM_LOAD_SHARED(ht->t.resize_initiated) && size < target_size) { | |
848d4088 MD |
1407 | uatomic_inc(&ht->in_progress_resize); |
1408 | cmm_smp_mb(); /* increment resize count before calling it */ | |
f9830efd MD |
1409 | work = malloc(sizeof(*work)); |
1410 | work->ht = ht; | |
14044b37 | 1411 | ht->cds_lfht_call_rcu(&work->head, do_resize_cb); |
4105056a | 1412 | CMM_STORE_SHARED(ht->t.resize_initiated, 1); |
f9830efd | 1413 | } |
ab7d5fc6 | 1414 | } |
3171717f | 1415 | |
f8994aee MD |
1416 | #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) |
1417 | ||
3171717f | 1418 | static |
4105056a | 1419 | void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size, |
3171717f MD |
1420 | unsigned long count) |
1421 | { | |
1422 | struct rcu_resize_work *work; | |
3171717f | 1423 | |
b8af5011 MD |
1424 | if (!(ht->flags & CDS_LFHT_AUTO_RESIZE)) |
1425 | return; | |
4105056a MD |
1426 | resize_target_update_count(ht, count); |
1427 | /* Store resize_target before read resize_initiated */ | |
1428 | cmm_smp_mb(); | |
1429 | if (!CMM_LOAD_SHARED(ht->t.resize_initiated)) { | |
3171717f MD |
1430 | uatomic_inc(&ht->in_progress_resize); |
1431 | cmm_smp_mb(); /* increment resize count before calling it */ | |
1432 | work = malloc(sizeof(*work)); | |
1433 | work->ht = ht; | |
1434 | ht->cds_lfht_call_rcu(&work->head, do_resize_cb); | |
4105056a | 1435 | CMM_STORE_SHARED(ht->t.resize_initiated, 1); |
3171717f MD |
1436 | } |
1437 | } | |
f8994aee MD |
1438 | |
1439 | #endif |