Commit | Line | Data |
---|---|---|
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 MD |
172 | //#define MIN_TABLE_SIZE 128 |
173 | #define MIN_TABLE_SIZE 1 | |
cd95516d | 174 | |
4105056a MD |
175 | #if (CAA_BITS_PER_LONG == 32) |
176 | #define MAX_TABLE_ORDER 32 | |
177 | #else | |
178 | #define MAX_TABLE_ORDER 64 | |
179 | #endif | |
180 | ||
181 | #ifndef min | |
182 | #define min(a, b) ((a) < (b) ? (a) : (b)) | |
183 | #endif | |
184 | ||
abc490a1 MD |
185 | #ifndef max |
186 | #define max(a, b) ((a) > (b) ? (a) : (b)) | |
187 | #endif | |
2ed95849 | 188 | |
d95bd160 MD |
189 | /* |
190 | * The removed flag needs to be updated atomically with the pointer. | |
191 | * The dummy flag does not require to be updated atomically with the | |
192 | * pointer, but it is added as a pointer low bit flag to save space. | |
193 | */ | |
d37166c6 | 194 | #define REMOVED_FLAG (1UL << 0) |
f5596c94 MD |
195 | #define DUMMY_FLAG (1UL << 1) |
196 | #define FLAGS_MASK ((1UL << 2) - 1) | |
d37166c6 | 197 | |
bb7b2f26 MD |
198 | /* Value of the end pointer. Should not interact with flags. */ |
199 | #define END_VALUE 0x4 | |
200 | ||
df44348d | 201 | struct ht_items_count { |
3171717f | 202 | unsigned long add, remove; |
df44348d MD |
203 | } __attribute__((aligned(CAA_CACHE_LINE_SIZE))); |
204 | ||
1475579c MD |
205 | struct rcu_level { |
206 | struct rcu_head head; | |
207 | struct _cds_lfht_node nodes[0]; | |
208 | }; | |
209 | ||
395270b6 | 210 | struct rcu_table { |
4105056a | 211 | unsigned long size; /* always a power of 2, shared (RCU) */ |
f9830efd | 212 | unsigned long resize_target; |
11519af6 | 213 | int resize_initiated; |
4105056a | 214 | struct rcu_level *tbl[MAX_TABLE_ORDER]; |
395270b6 MD |
215 | }; |
216 | ||
14044b37 | 217 | struct cds_lfht { |
4105056a | 218 | struct rcu_table t; |
14044b37 MD |
219 | cds_lfht_hash_fct hash_fct; |
220 | cds_lfht_compare_fct compare_fct; | |
732ad076 | 221 | unsigned long hash_seed; |
b8af5011 | 222 | int flags; |
5f511391 MD |
223 | /* |
224 | * We need to put the work threads offline (QSBR) when taking this | |
225 | * mutex, because we use synchronize_rcu within this mutex critical | |
226 | * section, which waits on read-side critical sections, and could | |
227 | * therefore cause grace-period deadlock if we hold off RCU G.P. | |
228 | * completion. | |
229 | */ | |
464a1ec9 | 230 | pthread_mutex_t resize_mutex; /* resize mutex: add/del mutex */ |
33c7c748 | 231 | unsigned int in_progress_resize, in_progress_destroy; |
14044b37 | 232 | void (*cds_lfht_call_rcu)(struct rcu_head *head, |
abc490a1 | 233 | void (*func)(struct rcu_head *head)); |
1475579c | 234 | void (*cds_lfht_synchronize_rcu)(void); |
01dbfa62 MD |
235 | void (*cds_lfht_rcu_read_lock)(void); |
236 | void (*cds_lfht_rcu_read_unlock)(void); | |
5f511391 MD |
237 | void (*cds_lfht_rcu_thread_offline)(void); |
238 | void (*cds_lfht_rcu_thread_online)(void); | |
df44348d MD |
239 | unsigned long count; /* global approximate item count */ |
240 | struct ht_items_count *percpu_count; /* per-cpu item count */ | |
2ed95849 MD |
241 | }; |
242 | ||
abc490a1 MD |
243 | struct rcu_resize_work { |
244 | struct rcu_head head; | |
14044b37 | 245 | struct cds_lfht *ht; |
abc490a1 | 246 | }; |
2ed95849 | 247 | |
76a73da8 MD |
248 | static |
249 | struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht, | |
250 | unsigned long size, | |
251 | struct cds_lfht_node *node, | |
252 | int unique, int dummy); | |
253 | ||
abc490a1 MD |
254 | /* |
255 | * Algorithm to reverse bits in a word by lookup table, extended to | |
256 | * 64-bit words. | |
f9830efd | 257 | * Source: |
abc490a1 | 258 | * http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable |
f9830efd | 259 | * Originally from Public Domain. |
abc490a1 MD |
260 | */ |
261 | ||
262 | static const uint8_t BitReverseTable256[256] = | |
2ed95849 | 263 | { |
abc490a1 MD |
264 | #define R2(n) (n), (n) + 2*64, (n) + 1*64, (n) + 3*64 |
265 | #define R4(n) R2(n), R2((n) + 2*16), R2((n) + 1*16), R2((n) + 3*16) | |
266 | #define R6(n) R4(n), R4((n) + 2*4 ), R4((n) + 1*4 ), R4((n) + 3*4 ) | |
267 | R6(0), R6(2), R6(1), R6(3) | |
268 | }; | |
269 | #undef R2 | |
270 | #undef R4 | |
271 | #undef R6 | |
2ed95849 | 272 | |
abc490a1 MD |
273 | static |
274 | uint8_t bit_reverse_u8(uint8_t v) | |
275 | { | |
276 | return BitReverseTable256[v]; | |
277 | } | |
ab7d5fc6 | 278 | |
abc490a1 MD |
279 | static __attribute__((unused)) |
280 | uint32_t bit_reverse_u32(uint32_t v) | |
281 | { | |
282 | return ((uint32_t) bit_reverse_u8(v) << 24) | | |
283 | ((uint32_t) bit_reverse_u8(v >> 8) << 16) | | |
284 | ((uint32_t) bit_reverse_u8(v >> 16) << 8) | | |
285 | ((uint32_t) bit_reverse_u8(v >> 24)); | |
2ed95849 MD |
286 | } |
287 | ||
abc490a1 MD |
288 | static __attribute__((unused)) |
289 | uint64_t bit_reverse_u64(uint64_t v) | |
2ed95849 | 290 | { |
abc490a1 MD |
291 | return ((uint64_t) bit_reverse_u8(v) << 56) | |
292 | ((uint64_t) bit_reverse_u8(v >> 8) << 48) | | |
293 | ((uint64_t) bit_reverse_u8(v >> 16) << 40) | | |
294 | ((uint64_t) bit_reverse_u8(v >> 24) << 32) | | |
295 | ((uint64_t) bit_reverse_u8(v >> 32) << 24) | | |
296 | ((uint64_t) bit_reverse_u8(v >> 40) << 16) | | |
297 | ((uint64_t) bit_reverse_u8(v >> 48) << 8) | | |
298 | ((uint64_t) bit_reverse_u8(v >> 56)); | |
299 | } | |
300 | ||
301 | static | |
302 | unsigned long bit_reverse_ulong(unsigned long v) | |
303 | { | |
304 | #if (CAA_BITS_PER_LONG == 32) | |
305 | return bit_reverse_u32(v); | |
306 | #else | |
307 | return bit_reverse_u64(v); | |
308 | #endif | |
309 | } | |
310 | ||
f9830efd | 311 | /* |
24365af7 MD |
312 | * fls: returns the position of the most significant bit. |
313 | * Returns 0 if no bit is set, else returns the position of the most | |
314 | * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit). | |
f9830efd | 315 | */ |
24365af7 MD |
316 | #if defined(__i386) || defined(__x86_64) |
317 | static inline | |
318 | unsigned int fls_u32(uint32_t x) | |
f9830efd | 319 | { |
24365af7 MD |
320 | int r; |
321 | ||
322 | asm("bsrl %1,%0\n\t" | |
323 | "jnz 1f\n\t" | |
324 | "movl $-1,%0\n\t" | |
325 | "1:\n\t" | |
326 | : "=r" (r) : "rm" (x)); | |
327 | return r + 1; | |
328 | } | |
329 | #define HAS_FLS_U32 | |
330 | #endif | |
331 | ||
332 | #if defined(__x86_64) | |
333 | static inline | |
334 | unsigned int fls_u64(uint64_t x) | |
335 | { | |
336 | long r; | |
337 | ||
338 | asm("bsrq %1,%0\n\t" | |
339 | "jnz 1f\n\t" | |
340 | "movq $-1,%0\n\t" | |
341 | "1:\n\t" | |
342 | : "=r" (r) : "rm" (x)); | |
343 | return r + 1; | |
344 | } | |
345 | #define HAS_FLS_U64 | |
346 | #endif | |
347 | ||
348 | #ifndef HAS_FLS_U64 | |
349 | static __attribute__((unused)) | |
350 | unsigned int fls_u64(uint64_t x) | |
351 | { | |
352 | unsigned int r = 64; | |
353 | ||
354 | if (!x) | |
355 | return 0; | |
356 | ||
357 | if (!(x & 0xFFFFFFFF00000000ULL)) { | |
358 | x <<= 32; | |
359 | r -= 32; | |
360 | } | |
361 | if (!(x & 0xFFFF000000000000ULL)) { | |
362 | x <<= 16; | |
363 | r -= 16; | |
364 | } | |
365 | if (!(x & 0xFF00000000000000ULL)) { | |
366 | x <<= 8; | |
367 | r -= 8; | |
368 | } | |
369 | if (!(x & 0xF000000000000000ULL)) { | |
370 | x <<= 4; | |
371 | r -= 4; | |
372 | } | |
373 | if (!(x & 0xC000000000000000ULL)) { | |
374 | x <<= 2; | |
375 | r -= 2; | |
376 | } | |
377 | if (!(x & 0x8000000000000000ULL)) { | |
378 | x <<= 1; | |
379 | r -= 1; | |
380 | } | |
381 | return r; | |
382 | } | |
383 | #endif | |
384 | ||
385 | #ifndef HAS_FLS_U32 | |
386 | static __attribute__((unused)) | |
387 | unsigned int fls_u32(uint32_t x) | |
388 | { | |
389 | unsigned int r = 32; | |
f9830efd | 390 | |
24365af7 MD |
391 | if (!x) |
392 | return 0; | |
393 | if (!(x & 0xFFFF0000U)) { | |
394 | x <<= 16; | |
395 | r -= 16; | |
396 | } | |
397 | if (!(x & 0xFF000000U)) { | |
398 | x <<= 8; | |
399 | r -= 8; | |
400 | } | |
401 | if (!(x & 0xF0000000U)) { | |
402 | x <<= 4; | |
403 | r -= 4; | |
404 | } | |
405 | if (!(x & 0xC0000000U)) { | |
406 | x <<= 2; | |
407 | r -= 2; | |
408 | } | |
409 | if (!(x & 0x80000000U)) { | |
410 | x <<= 1; | |
411 | r -= 1; | |
412 | } | |
413 | return r; | |
414 | } | |
415 | #endif | |
416 | ||
417 | unsigned int fls_ulong(unsigned long x) | |
f9830efd | 418 | { |
24365af7 MD |
419 | #if (CAA_BITS_PER_lONG == 32) |
420 | return fls_u32(x); | |
421 | #else | |
422 | return fls_u64(x); | |
423 | #endif | |
424 | } | |
f9830efd | 425 | |
24365af7 MD |
426 | int get_count_order_u32(uint32_t x) |
427 | { | |
428 | int order; | |
429 | ||
430 | order = fls_u32(x) - 1; | |
431 | if (x & (x - 1)) | |
432 | order++; | |
433 | return order; | |
434 | } | |
435 | ||
436 | int get_count_order_ulong(unsigned long x) | |
437 | { | |
438 | int order; | |
439 | ||
440 | order = fls_ulong(x) - 1; | |
441 | if (x & (x - 1)) | |
442 | order++; | |
443 | return order; | |
f9830efd MD |
444 | } |
445 | ||
98808fb1 MD |
446 | #ifdef POISON_FREE |
447 | #define poison_free(ptr) \ | |
448 | do { \ | |
449 | memset(ptr, 0x42, sizeof(*(ptr))); \ | |
450 | free(ptr); \ | |
451 | } while (0) | |
452 | #else | |
453 | #define poison_free(ptr) free(ptr) | |
454 | #endif | |
455 | ||
f9830efd | 456 | static |
4105056a | 457 | void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth); |
f9830efd | 458 | |
df44348d MD |
459 | /* |
460 | * If the sched_getcpu() and sysconf(_SC_NPROCESSORS_CONF) calls are | |
461 | * available, then we support hash table item accounting. | |
462 | * In the unfortunate event the number of CPUs reported would be | |
463 | * inaccurate, we use modulo arithmetic on the number of CPUs we got. | |
464 | */ | |
df44348d MD |
465 | #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) |
466 | ||
f8994aee | 467 | static |
4105056a | 468 | void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size, |
f8994aee MD |
469 | unsigned long count); |
470 | ||
df44348d MD |
471 | static long nr_cpus_mask = -1; |
472 | ||
473 | static | |
474 | struct ht_items_count *alloc_per_cpu_items_count(void) | |
475 | { | |
476 | struct ht_items_count *count; | |
477 | ||
478 | switch (nr_cpus_mask) { | |
479 | case -2: | |
480 | return NULL; | |
481 | case -1: | |
482 | { | |
483 | long maxcpus; | |
484 | ||
485 | maxcpus = sysconf(_SC_NPROCESSORS_CONF); | |
486 | if (maxcpus <= 0) { | |
487 | nr_cpus_mask = -2; | |
488 | return NULL; | |
489 | } | |
490 | /* | |
491 | * round up number of CPUs to next power of two, so we | |
492 | * can use & for modulo. | |
493 | */ | |
494 | maxcpus = 1UL << get_count_order_ulong(maxcpus); | |
495 | nr_cpus_mask = maxcpus - 1; | |
496 | } | |
497 | /* Fall-through */ | |
498 | default: | |
499 | return calloc(nr_cpus_mask + 1, sizeof(*count)); | |
500 | } | |
501 | } | |
502 | ||
503 | static | |
504 | void free_per_cpu_items_count(struct ht_items_count *count) | |
505 | { | |
98808fb1 | 506 | poison_free(count); |
df44348d MD |
507 | } |
508 | ||
509 | static | |
510 | int ht_get_cpu(void) | |
511 | { | |
512 | int cpu; | |
513 | ||
514 | assert(nr_cpus_mask >= 0); | |
515 | cpu = sched_getcpu(); | |
516 | if (unlikely(cpu < 0)) | |
517 | return cpu; | |
518 | else | |
519 | return cpu & nr_cpus_mask; | |
520 | } | |
521 | ||
522 | static | |
4105056a | 523 | void ht_count_add(struct cds_lfht *ht, unsigned long size) |
df44348d | 524 | { |
3171717f | 525 | unsigned long percpu_count; |
df44348d MD |
526 | int cpu; |
527 | ||
528 | if (unlikely(!ht->percpu_count)) | |
3171717f | 529 | return; |
df44348d MD |
530 | cpu = ht_get_cpu(); |
531 | if (unlikely(cpu < 0)) | |
3171717f MD |
532 | return; |
533 | percpu_count = uatomic_add_return(&ht->percpu_count[cpu].add, 1); | |
df44348d MD |
534 | if (unlikely(!(percpu_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) { |
535 | unsigned long count; | |
536 | ||
537 | dbg_printf("add percpu %lu\n", percpu_count); | |
538 | count = uatomic_add_return(&ht->count, | |
539 | 1UL << COUNT_COMMIT_ORDER); | |
540 | /* If power of 2 */ | |
541 | if (!(count & (count - 1))) { | |
4105056a | 542 | if ((count >> CHAIN_LEN_RESIZE_THRESHOLD) < size) |
f8994aee MD |
543 | return; |
544 | dbg_printf("add set global %lu\n", count); | |
4105056a | 545 | cds_lfht_resize_lazy_count(ht, size, |
6ea6bc67 | 546 | count >> (CHAIN_LEN_TARGET - 1)); |
df44348d MD |
547 | } |
548 | } | |
549 | } | |
550 | ||
551 | static | |
4105056a | 552 | void ht_count_remove(struct cds_lfht *ht, unsigned long size) |
df44348d MD |
553 | { |
554 | unsigned long percpu_count; | |
3171717f | 555 | int cpu; |
df44348d | 556 | |
3171717f MD |
557 | if (unlikely(!ht->percpu_count)) |
558 | return; | |
559 | cpu = ht_get_cpu(); | |
560 | if (unlikely(cpu < 0)) | |
561 | return; | |
562 | percpu_count = uatomic_add_return(&ht->percpu_count[cpu].remove, -1); | |
df44348d MD |
563 | if (unlikely(!(percpu_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) { |
564 | unsigned long count; | |
565 | ||
566 | dbg_printf("remove percpu %lu\n", percpu_count); | |
567 | count = uatomic_add_return(&ht->count, | |
3171717f | 568 | -(1UL << COUNT_COMMIT_ORDER)); |
df44348d MD |
569 | /* If power of 2 */ |
570 | if (!(count & (count - 1))) { | |
4105056a | 571 | if ((count >> CHAIN_LEN_RESIZE_THRESHOLD) >= size) |
f8994aee MD |
572 | return; |
573 | dbg_printf("remove set global %lu\n", count); | |
4105056a | 574 | cds_lfht_resize_lazy_count(ht, size, |
6ea6bc67 | 575 | count >> (CHAIN_LEN_TARGET - 1)); |
df44348d MD |
576 | } |
577 | } | |
578 | } | |
579 | ||
580 | #else /* #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */ | |
581 | ||
582 | static const long nr_cpus_mask = -1; | |
583 | ||
584 | static | |
585 | struct ht_items_count *alloc_per_cpu_items_count(void) | |
586 | { | |
587 | return NULL; | |
588 | } | |
589 | ||
590 | static | |
591 | void free_per_cpu_items_count(struct ht_items_count *count) | |
592 | { | |
593 | } | |
594 | ||
595 | static | |
4105056a | 596 | void ht_count_add(struct cds_lfht *ht, unsigned long size) |
df44348d MD |
597 | { |
598 | } | |
599 | ||
600 | static | |
4105056a | 601 | void ht_count_remove(struct cds_lfht *ht, unsigned long size) |
df44348d MD |
602 | { |
603 | } | |
604 | ||
605 | #endif /* #else #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */ | |
606 | ||
607 | ||
f9830efd | 608 | static |
4105056a | 609 | void check_resize(struct cds_lfht *ht, unsigned long size, uint32_t chain_len) |
f9830efd | 610 | { |
f8994aee MD |
611 | unsigned long count; |
612 | ||
b8af5011 MD |
613 | if (!(ht->flags & CDS_LFHT_AUTO_RESIZE)) |
614 | return; | |
f8994aee MD |
615 | count = uatomic_read(&ht->count); |
616 | /* | |
617 | * Use bucket-local length for small table expand and for | |
618 | * environments lacking per-cpu data support. | |
619 | */ | |
620 | if (count >= (1UL << COUNT_COMMIT_ORDER)) | |
621 | return; | |
24365af7 | 622 | if (chain_len > 100) |
f0c29ed7 | 623 | dbg_printf("WARNING: large chain length: %u.\n", |
24365af7 | 624 | chain_len); |
3390d470 | 625 | if (chain_len >= CHAIN_LEN_RESIZE_THRESHOLD) |
4105056a | 626 | cds_lfht_resize_lazy(ht, size, |
01370f0b | 627 | get_count_order_u32(chain_len - (CHAIN_LEN_TARGET - 1))); |
f9830efd MD |
628 | } |
629 | ||
abc490a1 | 630 | static |
14044b37 | 631 | struct cds_lfht_node *clear_flag(struct cds_lfht_node *node) |
abc490a1 | 632 | { |
14044b37 | 633 | return (struct cds_lfht_node *) (((unsigned long) node) & ~FLAGS_MASK); |
abc490a1 MD |
634 | } |
635 | ||
636 | static | |
14044b37 | 637 | int is_removed(struct cds_lfht_node *node) |
abc490a1 | 638 | { |
d37166c6 | 639 | return ((unsigned long) node) & REMOVED_FLAG; |
abc490a1 MD |
640 | } |
641 | ||
642 | static | |
14044b37 | 643 | struct cds_lfht_node *flag_removed(struct cds_lfht_node *node) |
abc490a1 | 644 | { |
14044b37 | 645 | return (struct cds_lfht_node *) (((unsigned long) node) | REMOVED_FLAG); |
abc490a1 MD |
646 | } |
647 | ||
f5596c94 | 648 | static |
14044b37 | 649 | int is_dummy(struct cds_lfht_node *node) |
f5596c94 MD |
650 | { |
651 | return ((unsigned long) node) & DUMMY_FLAG; | |
652 | } | |
653 | ||
654 | static | |
14044b37 | 655 | struct cds_lfht_node *flag_dummy(struct cds_lfht_node *node) |
f5596c94 | 656 | { |
14044b37 | 657 | return (struct cds_lfht_node *) (((unsigned long) node) | DUMMY_FLAG); |
f5596c94 | 658 | } |
bb7b2f26 MD |
659 | |
660 | static | |
661 | struct cds_lfht_node *get_end(void) | |
662 | { | |
663 | return (struct cds_lfht_node *) END_VALUE; | |
664 | } | |
665 | ||
666 | static | |
667 | int is_end(struct cds_lfht_node *node) | |
668 | { | |
669 | return clear_flag(node) == (struct cds_lfht_node *) END_VALUE; | |
670 | } | |
671 | ||
abc490a1 | 672 | static |
f9830efd | 673 | unsigned long _uatomic_max(unsigned long *ptr, unsigned long v) |
abc490a1 MD |
674 | { |
675 | unsigned long old1, old2; | |
676 | ||
677 | old1 = uatomic_read(ptr); | |
678 | do { | |
679 | old2 = old1; | |
680 | if (old2 >= v) | |
f9830efd | 681 | return old2; |
abc490a1 | 682 | } while ((old1 = uatomic_cmpxchg(ptr, old2, v)) != old2); |
f9830efd | 683 | return v; |
abc490a1 MD |
684 | } |
685 | ||
1475579c MD |
686 | static |
687 | void cds_lfht_free_level(struct rcu_head *head) | |
688 | { | |
689 | struct rcu_level *l = | |
690 | caa_container_of(head, struct rcu_level, head); | |
98808fb1 | 691 | poison_free(l); |
1475579c MD |
692 | } |
693 | ||
273399de MD |
694 | /* |
695 | * Remove all logically deleted nodes from a bucket up to a certain node key. | |
696 | */ | |
697 | static | |
76a73da8 | 698 | int _cds_lfht_gc_bucket(struct cds_lfht_node *dummy, struct cds_lfht_node *node) |
273399de | 699 | { |
14044b37 | 700 | struct cds_lfht_node *iter_prev, *iter, *next, *new_next; |
273399de | 701 | |
c90201ac MD |
702 | assert(!is_dummy(dummy)); |
703 | assert(!is_removed(dummy)); | |
704 | assert(!is_dummy(node)); | |
705 | assert(!is_removed(node)); | |
273399de MD |
706 | for (;;) { |
707 | iter_prev = dummy; | |
708 | /* We can always skip the dummy node initially */ | |
cc4fcb10 | 709 | iter = rcu_dereference(iter_prev->p.next); |
76a73da8 MD |
710 | if (unlikely(iter == NULL)) { |
711 | /* | |
712 | * We are executing concurrently with a hash table | |
713 | * expand, so we see a dummy node with NULL next value. | |
714 | * Help expand by linking this node into the list and | |
715 | * retry. | |
716 | */ | |
717 | return 1; | |
718 | } | |
cc4fcb10 | 719 | assert(iter_prev->p.reverse_hash <= node->p.reverse_hash); |
bd4db153 MD |
720 | /* |
721 | * We should never be called with dummy (start of chain) | |
722 | * and logically removed node (end of path compression | |
723 | * marker) being the actual same node. This would be a | |
724 | * bug in the algorithm implementation. | |
725 | */ | |
726 | assert(dummy != node); | |
273399de | 727 | for (;;) { |
bb7b2f26 MD |
728 | assert(iter != NULL); |
729 | if (unlikely(is_end(iter))) | |
76a73da8 | 730 | return 0; |
76412f24 | 731 | if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash)) |
76a73da8 | 732 | return 0; |
cc4fcb10 | 733 | next = rcu_dereference(clear_flag(iter)->p.next); |
76412f24 | 734 | if (likely(is_removed(next))) |
273399de | 735 | break; |
b453eae1 | 736 | iter_prev = clear_flag(iter); |
273399de MD |
737 | iter = next; |
738 | } | |
739 | assert(!is_removed(iter)); | |
f5596c94 MD |
740 | if (is_dummy(iter)) |
741 | new_next = flag_dummy(clear_flag(next)); | |
742 | else | |
743 | new_next = clear_flag(next); | |
bb7b2f26 | 744 | assert(new_next != NULL); |
f5596c94 | 745 | (void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next); |
273399de | 746 | } |
76a73da8 | 747 | return 0; |
273399de MD |
748 | } |
749 | ||
abc490a1 | 750 | static |
4105056a MD |
751 | struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht, |
752 | unsigned long size, | |
753 | struct cds_lfht_node *node, | |
754 | int unique, int dummy) | |
abc490a1 | 755 | { |
14044b37 | 756 | struct cds_lfht_node *iter_prev, *iter, *next, *new_node, *new_next, |
f5596c94 | 757 | *dummy_node; |
14044b37 | 758 | struct _cds_lfht_node *lookup; |
24365af7 | 759 | unsigned long hash, index, order; |
bb7b2f26 | 760 | int force_dummy = 0; |
abc490a1 | 761 | |
c90201ac MD |
762 | assert(!is_dummy(node)); |
763 | assert(!is_removed(node)); | |
4105056a | 764 | if (!size) { |
f5596c94 | 765 | assert(dummy); |
bb7b2f26 | 766 | node->p.next = flag_dummy(get_end()); |
18117871 MD |
767 | return node; /* Initial first add (head) */ |
768 | } | |
cc4fcb10 | 769 | hash = bit_reverse_ulong(node->p.reverse_hash); |
abc490a1 | 770 | for (;;) { |
f9830efd | 771 | uint32_t chain_len = 0; |
abc490a1 | 772 | |
11519af6 MD |
773 | /* |
774 | * iter_prev points to the non-removed node prior to the | |
775 | * insert location. | |
11519af6 | 776 | */ |
4105056a | 777 | index = hash & (size - 1); |
24365af7 | 778 | order = get_count_order_ulong(index + 1); |
4105056a | 779 | lookup = &ht->t.tbl[order]->nodes[index & ((!order ? 0 : (1UL << (order - 1))) - 1)]; |
14044b37 | 780 | iter_prev = (struct cds_lfht_node *) lookup; |
11519af6 | 781 | /* We can always skip the dummy node initially */ |
cc4fcb10 | 782 | iter = rcu_dereference(iter_prev->p.next); |
76a73da8 MD |
783 | if (unlikely(iter == NULL)) { |
784 | /* | |
785 | * We are executing concurrently with a hash table | |
786 | * expand, so we see a dummy node with NULL next value. | |
787 | * Help expand by linking this node into the list and | |
788 | * retry. | |
789 | */ | |
790 | (void) _cds_lfht_add(ht, size >> 1, iter_prev, 0, 1); | |
791 | continue; /* retry */ | |
792 | } | |
cc4fcb10 | 793 | assert(iter_prev->p.reverse_hash <= node->p.reverse_hash); |
abc490a1 | 794 | for (;;) { |
bb7b2f26 | 795 | assert(iter != NULL); |
76a73da8 MD |
796 | /* |
797 | * When adding a dummy node, we allow concurrent | |
798 | * add/removal to help. If we find the dummy node in | |
799 | * place, skip its insertion. | |
800 | */ | |
801 | if (unlikely(dummy && clear_flag(iter) == node)) | |
802 | return node; | |
bb7b2f26 | 803 | if (unlikely(is_end(iter))) |
273399de | 804 | goto insert; |
76412f24 | 805 | if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash)) |
273399de | 806 | goto insert; |
cc4fcb10 | 807 | next = rcu_dereference(clear_flag(iter)->p.next); |
76412f24 | 808 | if (unlikely(is_removed(next))) |
9dba85be | 809 | goto gc_node; |
e43f23f8 | 810 | if (unique |
1b81fe1a | 811 | && !is_dummy(next) |
e43f23f8 MD |
812 | && !ht->compare_fct(node->key, node->key_len, |
813 | clear_flag(iter)->key, | |
814 | clear_flag(iter)->key_len)) | |
18117871 | 815 | return clear_flag(iter); |
11519af6 | 816 | /* Only account for identical reverse hash once */ |
24365af7 MD |
817 | if (iter_prev->p.reverse_hash != clear_flag(iter)->p.reverse_hash |
818 | && !is_dummy(next)) | |
4105056a | 819 | check_resize(ht, size, ++chain_len); |
11519af6 | 820 | iter_prev = clear_flag(iter); |
273399de | 821 | iter = next; |
abc490a1 | 822 | } |
273399de | 823 | insert: |
7ec59d3b | 824 | assert(node != clear_flag(iter)); |
11519af6 | 825 | assert(!is_removed(iter_prev)); |
c90201ac | 826 | assert(!is_removed(iter)); |
f000907d | 827 | assert(iter_prev != node); |
bb7b2f26 | 828 | if (!dummy) { |
1b81fe1a | 829 | node->p.next = clear_flag(iter); |
bb7b2f26 MD |
830 | } else { |
831 | /* | |
832 | * Dummy node insertion is performed concurrently (help | |
833 | * scheme). We try to link its next node, and if this | |
834 | * succeeds, it _means_ it's us who link this dummy node | |
835 | * into the table. force_dummy is set as soon as we | |
836 | * succeed this cmpxchg within this function. | |
837 | */ | |
838 | if (!force_dummy) { | |
839 | if (uatomic_cmpxchg(&node->p.next, NULL, | |
840 | flag_dummy(clear_flag(iter))) != NULL) { | |
841 | return NULL; | |
842 | } | |
843 | force_dummy = 1; | |
844 | } else { | |
845 | node->p.next = flag_dummy(clear_flag(iter)); | |
846 | } | |
847 | } | |
f5596c94 MD |
848 | if (is_dummy(iter)) |
849 | new_node = flag_dummy(node); | |
850 | else | |
851 | new_node = node; | |
bb7b2f26 | 852 | assert(new_node != NULL); |
cc4fcb10 | 853 | if (uatomic_cmpxchg(&iter_prev->p.next, iter, |
f5596c94 | 854 | new_node) != iter) |
273399de | 855 | continue; /* retry */ |
11519af6 | 856 | else |
273399de | 857 | goto gc_end; |
9dba85be MD |
858 | gc_node: |
859 | assert(!is_removed(iter)); | |
f5596c94 MD |
860 | if (is_dummy(iter)) |
861 | new_next = flag_dummy(clear_flag(next)); | |
862 | else | |
863 | new_next = clear_flag(next); | |
bb7b2f26 | 864 | assert(new_next != NULL); |
f5596c94 | 865 | (void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next); |
273399de | 866 | /* retry */ |
464a1ec9 | 867 | } |
273399de MD |
868 | gc_end: |
869 | /* Garbage collect logically removed nodes in the bucket */ | |
4105056a | 870 | index = hash & (size - 1); |
24365af7 | 871 | order = get_count_order_ulong(index + 1); |
4105056a | 872 | lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1)) - 1))]; |
14044b37 | 873 | dummy_node = (struct cds_lfht_node *) lookup; |
76a73da8 MD |
874 | if (_cds_lfht_gc_bucket(dummy_node, node)) { |
875 | /* Help expand */ | |
876 | (void) _cds_lfht_add(ht, size >> 1, dummy_node, 0, 1); | |
877 | goto gc_end; /* retry */ | |
878 | } | |
18117871 | 879 | return node; |
abc490a1 | 880 | } |
464a1ec9 | 881 | |
abc490a1 | 882 | static |
4105056a MD |
883 | int _cds_lfht_remove(struct cds_lfht *ht, unsigned long size, |
884 | struct cds_lfht_node *node, | |
885 | int dummy_removal) | |
abc490a1 | 886 | { |
14044b37 MD |
887 | struct cds_lfht_node *dummy, *next, *old; |
888 | struct _cds_lfht_node *lookup; | |
abc490a1 | 889 | int flagged = 0; |
24365af7 | 890 | unsigned long hash, index, order; |
5e28c532 | 891 | |
7ec59d3b | 892 | /* logically delete the node */ |
c90201ac MD |
893 | assert(!is_dummy(node)); |
894 | assert(!is_removed(node)); | |
cc4fcb10 | 895 | old = rcu_dereference(node->p.next); |
7ec59d3b MD |
896 | do { |
897 | next = old; | |
76412f24 | 898 | if (unlikely(is_removed(next))) |
7ec59d3b | 899 | goto end; |
1475579c MD |
900 | if (dummy_removal) |
901 | assert(is_dummy(next)); | |
902 | else | |
903 | assert(!is_dummy(next)); | |
bb7b2f26 | 904 | assert(next != NULL); |
cc4fcb10 | 905 | old = uatomic_cmpxchg(&node->p.next, next, |
7ec59d3b MD |
906 | flag_removed(next)); |
907 | } while (old != next); | |
908 | ||
909 | /* We performed the (logical) deletion. */ | |
910 | flagged = 1; | |
911 | ||
912 | /* | |
913 | * Ensure that the node is not visible to readers anymore: lookup for | |
273399de MD |
914 | * the node, and remove it (along with any other logically removed node) |
915 | * if found. | |
11519af6 | 916 | */ |
76a73da8 | 917 | gc_retry: |
cc4fcb10 | 918 | hash = bit_reverse_ulong(node->p.reverse_hash); |
4105056a MD |
919 | assert(size > 0); |
920 | index = hash & (size - 1); | |
24365af7 | 921 | order = get_count_order_ulong(index + 1); |
4105056a | 922 | lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1)) - 1))]; |
14044b37 | 923 | dummy = (struct cds_lfht_node *) lookup; |
76a73da8 MD |
924 | if (_cds_lfht_gc_bucket(dummy, node)) { |
925 | /* Help expand */ | |
926 | (void) _cds_lfht_add(ht, size >> 1, dummy, 0, 1); | |
927 | goto gc_retry; /* retry */ | |
928 | } | |
2ed95849 | 929 | end: |
11519af6 MD |
930 | /* |
931 | * Only the flagging action indicated that we (and no other) | |
932 | * removed the node from the hash. | |
933 | */ | |
7ec59d3b | 934 | if (flagged) { |
cc4fcb10 | 935 | assert(is_removed(rcu_dereference(node->p.next))); |
11519af6 | 936 | return 0; |
7ec59d3b | 937 | } else |
11519af6 | 938 | return -ENOENT; |
abc490a1 | 939 | } |
2ed95849 | 940 | |
4105056a MD |
941 | static |
942 | void init_table_hash(struct cds_lfht *ht, unsigned long i, | |
943 | unsigned long len) | |
944 | { | |
945 | unsigned long j; | |
946 | ||
947 | for (j = 0; j < len; j++) { | |
948 | struct cds_lfht_node *new_node = | |
949 | (struct cds_lfht_node *) &ht->t.tbl[i]->nodes[j]; | |
950 | ||
951 | dbg_printf("init hash entry: i %lu j %lu hash %lu\n", | |
952 | i, j, !i ? 0 : (1UL << (i - 1)) + j); | |
953 | new_node->p.reverse_hash = | |
954 | bit_reverse_ulong(!i ? 0 : (1UL << (i - 1)) + j); | |
955 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) | |
956 | break; | |
957 | } | |
958 | } | |
959 | ||
e8de508e MD |
960 | /* |
961 | * Holding RCU read lock to protect _cds_lfht_add against memory | |
962 | * reclaim that could be performed by other call_rcu worker threads (ABA | |
963 | * problem). | |
964 | */ | |
4105056a MD |
965 | static |
966 | void init_table_link(struct cds_lfht *ht, unsigned long i, unsigned long len) | |
967 | { | |
968 | unsigned long j; | |
969 | ||
5f511391 | 970 | ht->cds_lfht_rcu_thread_online(); |
4105056a MD |
971 | ht->cds_lfht_rcu_read_lock(); |
972 | for (j = 0; j < len; j++) { | |
973 | struct cds_lfht_node *new_node = | |
974 | (struct cds_lfht_node *) &ht->t.tbl[i]->nodes[j]; | |
975 | ||
976 | dbg_printf("init link: i %lu j %lu hash %lu\n", | |
977 | i, j, !i ? 0 : (1UL << (i - 1)) + j); | |
978 | (void) _cds_lfht_add(ht, !i ? 0 : (1UL << (i - 1)), | |
979 | new_node, 0, 1); | |
980 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) | |
981 | break; | |
982 | } | |
983 | ht->cds_lfht_rcu_read_unlock(); | |
5f511391 | 984 | ht->cds_lfht_rcu_thread_offline(); |
4105056a MD |
985 | } |
986 | ||
abc490a1 | 987 | static |
4105056a | 988 | void init_table(struct cds_lfht *ht, |
24365af7 MD |
989 | unsigned long first_order, unsigned long len_order) |
990 | { | |
991 | unsigned long i, end_order; | |
992 | ||
f0c29ed7 | 993 | dbg_printf("init table: first_order %lu end_order %lu\n", |
24365af7 MD |
994 | first_order, first_order + len_order); |
995 | end_order = first_order + len_order; | |
24365af7 | 996 | for (i = first_order; i < end_order; i++) { |
4105056a | 997 | unsigned long len; |
24365af7 MD |
998 | |
999 | len = !i ? 1 : 1UL << (i - 1); | |
f0c29ed7 | 1000 | dbg_printf("init order %lu len: %lu\n", i, len); |
4d676753 MD |
1001 | |
1002 | /* Stop expand if the resize target changes under us */ | |
1003 | if (CMM_LOAD_SHARED(ht->t.resize_target) < (!i ? 1 : (1UL << i))) | |
1004 | break; | |
1005 | ||
4105056a | 1006 | ht->t.tbl[i] = calloc(1, sizeof(struct rcu_level) |
1475579c | 1007 | + (len * sizeof(struct _cds_lfht_node))); |
4105056a MD |
1008 | |
1009 | /* Set all dummy nodes reverse hash values for a level */ | |
1010 | init_table_hash(ht, i, len); | |
1011 | ||
76a73da8 MD |
1012 | /* |
1013 | * Update table size. At this point, concurrent add/remove see | |
1014 | * dummy nodes with correctly initialized reverse hash value, | |
1015 | * but with NULL next pointers. If they do, they can help us | |
1016 | * link the dummy nodes into the list and retry. | |
1017 | */ | |
1018 | cmm_smp_wmb(); /* populate data before RCU size */ | |
1019 | CMM_STORE_SHARED(ht->t.size, !i ? 1 : (1UL << i)); | |
1020 | ||
4105056a MD |
1021 | /* |
1022 | * Link all dummy nodes into the table. Concurrent | |
1023 | * add/remove are helping us. | |
1024 | */ | |
1025 | init_table_link(ht, i, len); | |
1026 | ||
4105056a MD |
1027 | dbg_printf("init new size: %lu\n", !i ? 1 : (1UL << i)); |
1028 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) | |
1029 | break; | |
1030 | } | |
1031 | } | |
1032 | ||
e8de508e MD |
1033 | /* |
1034 | * Holding RCU read lock to protect _cds_lfht_remove against memory | |
1035 | * reclaim that could be performed by other call_rcu worker threads (ABA | |
1036 | * problem). | |
1037 | * For a single level, we logically remove and garbage collect each node. | |
1038 | * | |
1039 | * As a design choice, we perform logical removal and garbage collection on a | |
1040 | * node-per-node basis to simplify this algorithm. We also assume keeping good | |
1041 | * cache locality of the operation would overweight possible performance gain | |
1042 | * that could be achieved by batching garbage collection for multiple levels. | |
1043 | * However, this would have to be justified by benchmarks. | |
1044 | * | |
1045 | * Concurrent removal and add operations are helping us perform garbage | |
1046 | * collection of logically removed nodes. We guarantee that all logically | |
1047 | * removed nodes have been garbage-collected (unlinked) before call_rcu is | |
1048 | * invoked to free a hole level of dummy nodes (after a grace period). | |
1049 | * | |
1050 | * Logical removal and garbage collection can therefore be done in batch or on a | |
1051 | * node-per-node basis, as long as the guarantee above holds. | |
1052 | */ | |
4105056a MD |
1053 | static |
1054 | void remove_table(struct cds_lfht *ht, unsigned long i, unsigned long len) | |
1055 | { | |
1056 | unsigned long j; | |
1057 | ||
5f511391 | 1058 | ht->cds_lfht_rcu_thread_online(); |
4105056a MD |
1059 | ht->cds_lfht_rcu_read_lock(); |
1060 | for (j = 0; j < len; j++) { | |
1061 | struct cds_lfht_node *fini_node = | |
1062 | (struct cds_lfht_node *) &ht->t.tbl[i]->nodes[j]; | |
1063 | ||
1064 | dbg_printf("remove entry: i %lu j %lu hash %lu\n", | |
1065 | i, j, !i ? 0 : (1UL << (i - 1)) + j); | |
1066 | fini_node->p.reverse_hash = | |
1067 | bit_reverse_ulong(!i ? 0 : (1UL << (i - 1)) + j); | |
1068 | (void) _cds_lfht_remove(ht, !i ? 0 : (1UL << (i - 1)), | |
1069 | fini_node, 1); | |
33c7c748 MD |
1070 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) |
1071 | break; | |
abc490a1 | 1072 | } |
4105056a | 1073 | ht->cds_lfht_rcu_read_unlock(); |
5f511391 | 1074 | ht->cds_lfht_rcu_thread_offline(); |
2ed95849 MD |
1075 | } |
1076 | ||
1475579c | 1077 | static |
4105056a | 1078 | void fini_table(struct cds_lfht *ht, |
1475579c MD |
1079 | unsigned long first_order, unsigned long len_order) |
1080 | { | |
1081 | long i, end_order; | |
1082 | ||
1083 | dbg_printf("fini table: first_order %lu end_order %lu\n", | |
1084 | first_order, first_order + len_order); | |
1085 | end_order = first_order + len_order; | |
1086 | assert(first_order > 0); | |
1475579c | 1087 | for (i = end_order - 1; i >= first_order; i--) { |
4105056a | 1088 | unsigned long len; |
1475579c MD |
1089 | |
1090 | len = !i ? 1 : 1UL << (i - 1); | |
1091 | dbg_printf("fini order %lu len: %lu\n", i, len); | |
4105056a | 1092 | |
4d676753 MD |
1093 | /* Stop shrink if the resize target changes under us */ |
1094 | if (CMM_LOAD_SHARED(ht->t.resize_target) > (1UL << (i - 1))) | |
1095 | break; | |
1096 | ||
1097 | cmm_smp_wmb(); /* populate data before RCU size */ | |
1098 | CMM_STORE_SHARED(ht->t.size, 1UL << (i - 1)); | |
1099 | ||
1100 | /* | |
1101 | * We need to wait for all add operations to reach Q.S. (and | |
1102 | * thus use the new table for lookups) before we can start | |
1103 | * releasing the old dummy nodes. Otherwise their lookup will | |
1104 | * return a logically removed node as insert position. | |
1105 | */ | |
1106 | ht->cds_lfht_synchronize_rcu(); | |
1107 | ||
21263e21 | 1108 | /* |
4105056a MD |
1109 | * Set "removed" flag in dummy nodes about to be removed. |
1110 | * Unlink all now-logically-removed dummy node pointers. | |
1111 | * Concurrent add/remove operation are helping us doing | |
1112 | * the gc. | |
21263e21 | 1113 | */ |
4105056a MD |
1114 | remove_table(ht, i, len); |
1115 | ||
1116 | ht->cds_lfht_call_rcu(&ht->t.tbl[i]->head, cds_lfht_free_level); | |
1117 | ||
1118 | dbg_printf("fini new size: %lu\n", 1UL << i); | |
1475579c MD |
1119 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) |
1120 | break; | |
1121 | } | |
1475579c MD |
1122 | } |
1123 | ||
14044b37 MD |
1124 | struct cds_lfht *cds_lfht_new(cds_lfht_hash_fct hash_fct, |
1125 | cds_lfht_compare_fct compare_fct, | |
1126 | unsigned long hash_seed, | |
1127 | unsigned long init_size, | |
b8af5011 | 1128 | int flags, |
14044b37 | 1129 | void (*cds_lfht_call_rcu)(struct rcu_head *head, |
1475579c | 1130 | void (*func)(struct rcu_head *head)), |
01dbfa62 MD |
1131 | void (*cds_lfht_synchronize_rcu)(void), |
1132 | void (*cds_lfht_rcu_read_lock)(void), | |
5f511391 MD |
1133 | void (*cds_lfht_rcu_read_unlock)(void), |
1134 | void (*cds_lfht_rcu_thread_offline)(void), | |
1135 | void (*cds_lfht_rcu_thread_online)(void)) | |
abc490a1 | 1136 | { |
14044b37 | 1137 | struct cds_lfht *ht; |
24365af7 | 1138 | unsigned long order; |
abc490a1 | 1139 | |
8129be4e | 1140 | /* init_size must be power of two */ |
49619ea0 | 1141 | if (init_size && (init_size & (init_size - 1))) |
8129be4e | 1142 | return NULL; |
14044b37 | 1143 | ht = calloc(1, sizeof(struct cds_lfht)); |
abc490a1 | 1144 | ht->hash_fct = hash_fct; |
732ad076 MD |
1145 | ht->compare_fct = compare_fct; |
1146 | ht->hash_seed = hash_seed; | |
14044b37 | 1147 | ht->cds_lfht_call_rcu = cds_lfht_call_rcu; |
1475579c | 1148 | ht->cds_lfht_synchronize_rcu = cds_lfht_synchronize_rcu; |
01dbfa62 MD |
1149 | ht->cds_lfht_rcu_read_lock = cds_lfht_rcu_read_lock; |
1150 | ht->cds_lfht_rcu_read_unlock = cds_lfht_rcu_read_unlock; | |
5f511391 MD |
1151 | ht->cds_lfht_rcu_thread_offline = cds_lfht_rcu_thread_offline; |
1152 | ht->cds_lfht_rcu_thread_online = cds_lfht_rcu_thread_online; | |
df44348d | 1153 | ht->percpu_count = alloc_per_cpu_items_count(); |
abc490a1 MD |
1154 | /* this mutex should not nest in read-side C.S. */ |
1155 | pthread_mutex_init(&ht->resize_mutex, NULL); | |
cd95516d | 1156 | order = get_count_order_ulong(max(init_size, MIN_TABLE_SIZE)) + 1; |
b8af5011 | 1157 | ht->flags = flags; |
5f511391 | 1158 | ht->cds_lfht_rcu_thread_offline(); |
f000907d | 1159 | pthread_mutex_lock(&ht->resize_mutex); |
4d676753 | 1160 | ht->t.resize_target = 1UL << (order - 1); |
4105056a | 1161 | init_table(ht, 0, order); |
f000907d | 1162 | pthread_mutex_unlock(&ht->resize_mutex); |
5f511391 | 1163 | ht->cds_lfht_rcu_thread_online(); |
abc490a1 MD |
1164 | return ht; |
1165 | } | |
1166 | ||
14044b37 | 1167 | struct cds_lfht_node *cds_lfht_lookup(struct cds_lfht *ht, void *key, size_t key_len) |
2ed95849 | 1168 | { |
bb7b2f26 | 1169 | struct cds_lfht_node *node, *next, *dummy_node; |
14044b37 | 1170 | struct _cds_lfht_node *lookup; |
4105056a | 1171 | unsigned long hash, reverse_hash, index, order, size; |
2ed95849 | 1172 | |
732ad076 | 1173 | hash = ht->hash_fct(key, key_len, ht->hash_seed); |
abc490a1 | 1174 | reverse_hash = bit_reverse_ulong(hash); |
464a1ec9 | 1175 | |
bb7b2f26 | 1176 | restart: |
4105056a MD |
1177 | size = rcu_dereference(ht->t.size); |
1178 | index = hash & (size - 1); | |
24365af7 | 1179 | order = get_count_order_ulong(index + 1); |
4105056a | 1180 | lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1))) - 1)]; |
f0c29ed7 | 1181 | dbg_printf("lookup hash %lu index %lu order %lu aridx %lu\n", |
554c284e | 1182 | hash, index, order, index & (!order ? 0 : ((1UL << (order - 1)) - 1))); |
bb7b2f26 MD |
1183 | dummy_node = (struct cds_lfht_node *) lookup; |
1184 | /* We can always skip the dummy node initially */ | |
1185 | node = rcu_dereference(dummy_node->p.next); | |
1186 | if (unlikely(node == NULL)) { | |
1187 | /* | |
1188 | * We are executing concurrently with a hash table | |
1189 | * expand, so we see a dummy node with NULL next value. | |
1190 | * Help expand by linking this node into the list and | |
1191 | * retry. | |
1192 | */ | |
1193 | (void) _cds_lfht_add(ht, size >> 1, dummy_node, 0, 1); | |
1194 | goto restart; /* retry */ | |
1195 | } | |
1196 | node = clear_flag(node); | |
2ed95849 | 1197 | for (;;) { |
bb7b2f26 MD |
1198 | if (unlikely(is_end(node))) { |
1199 | node = NULL; | |
abc490a1 | 1200 | break; |
bb7b2f26 | 1201 | } |
cc4fcb10 | 1202 | if (unlikely(node->p.reverse_hash > reverse_hash)) { |
abc490a1 MD |
1203 | node = NULL; |
1204 | break; | |
2ed95849 | 1205 | } |
1b81fe1a MD |
1206 | next = rcu_dereference(node->p.next); |
1207 | if (likely(!is_removed(next)) | |
1208 | && !is_dummy(next) | |
49c2e2d6 | 1209 | && likely(!ht->compare_fct(node->key, node->key_len, key, key_len))) { |
273399de | 1210 | break; |
2ed95849 | 1211 | } |
1b81fe1a | 1212 | node = clear_flag(next); |
2ed95849 | 1213 | } |
1b81fe1a | 1214 | assert(!node || !is_dummy(rcu_dereference(node->p.next))); |
abc490a1 MD |
1215 | return node; |
1216 | } | |
e0ba718a | 1217 | |
a481e5ff MD |
1218 | struct cds_lfht_node *cds_lfht_next(struct cds_lfht *ht, |
1219 | struct cds_lfht_node *node) | |
1220 | { | |
1221 | struct cds_lfht_node *next; | |
1222 | unsigned long reverse_hash; | |
1223 | void *key; | |
1224 | size_t key_len; | |
1225 | ||
1226 | reverse_hash = node->p.reverse_hash; | |
1227 | key = node->key; | |
1228 | key_len = node->key_len; | |
1229 | next = rcu_dereference(node->p.next); | |
1230 | node = clear_flag(next); | |
1231 | ||
1232 | for (;;) { | |
bb7b2f26 MD |
1233 | if (unlikely(is_end(node))) { |
1234 | node = NULL; | |
a481e5ff | 1235 | break; |
bb7b2f26 | 1236 | } |
a481e5ff MD |
1237 | if (unlikely(node->p.reverse_hash > reverse_hash)) { |
1238 | node = NULL; | |
1239 | break; | |
1240 | } | |
1241 | next = rcu_dereference(node->p.next); | |
1242 | if (likely(!is_removed(next)) | |
1243 | && !is_dummy(next) | |
1244 | && likely(!ht->compare_fct(node->key, node->key_len, key, key_len))) { | |
1245 | break; | |
1246 | } | |
1247 | node = clear_flag(next); | |
1248 | } | |
1249 | assert(!node || !is_dummy(rcu_dereference(node->p.next))); | |
1250 | return node; | |
1251 | } | |
1252 | ||
14044b37 | 1253 | void cds_lfht_add(struct cds_lfht *ht, struct cds_lfht_node *node) |
abc490a1 | 1254 | { |
4105056a | 1255 | unsigned long hash, size; |
ab7d5fc6 | 1256 | |
49c2e2d6 | 1257 | hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed); |
cc4fcb10 | 1258 | node->p.reverse_hash = bit_reverse_ulong((unsigned long) hash); |
2ed95849 | 1259 | |
4105056a MD |
1260 | size = rcu_dereference(ht->t.size); |
1261 | (void) _cds_lfht_add(ht, size, node, 0, 0); | |
1262 | ht_count_add(ht, size); | |
3eca1b8c MD |
1263 | } |
1264 | ||
14044b37 MD |
1265 | struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht, |
1266 | struct cds_lfht_node *node) | |
3eca1b8c | 1267 | { |
4105056a | 1268 | unsigned long hash, size; |
df44348d | 1269 | struct cds_lfht_node *ret; |
3eca1b8c | 1270 | |
49c2e2d6 | 1271 | hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed); |
cc4fcb10 | 1272 | node->p.reverse_hash = bit_reverse_ulong((unsigned long) hash); |
3eca1b8c | 1273 | |
4105056a MD |
1274 | size = rcu_dereference(ht->t.size); |
1275 | ret = _cds_lfht_add(ht, size, node, 1, 0); | |
df44348d | 1276 | if (ret != node) |
4105056a | 1277 | ht_count_add(ht, size); |
df44348d | 1278 | return ret; |
2ed95849 MD |
1279 | } |
1280 | ||
14044b37 | 1281 | int cds_lfht_remove(struct cds_lfht *ht, struct cds_lfht_node *node) |
2ed95849 | 1282 | { |
4105056a | 1283 | unsigned long size; |
df44348d | 1284 | int ret; |
abc490a1 | 1285 | |
4105056a MD |
1286 | size = rcu_dereference(ht->t.size); |
1287 | ret = _cds_lfht_remove(ht, size, node, 0); | |
df44348d | 1288 | if (!ret) |
4105056a | 1289 | ht_count_remove(ht, size); |
df44348d | 1290 | return ret; |
2ed95849 | 1291 | } |
ab7d5fc6 | 1292 | |
abc490a1 | 1293 | static |
14044b37 | 1294 | int cds_lfht_delete_dummy(struct cds_lfht *ht) |
674f7a69 | 1295 | { |
14044b37 MD |
1296 | struct cds_lfht_node *node; |
1297 | struct _cds_lfht_node *lookup; | |
4105056a | 1298 | unsigned long order, i, size; |
674f7a69 | 1299 | |
abc490a1 | 1300 | /* Check that the table is empty */ |
4105056a | 1301 | lookup = &ht->t.tbl[0]->nodes[0]; |
14044b37 | 1302 | node = (struct cds_lfht_node *) lookup; |
abc490a1 | 1303 | do { |
1b81fe1a MD |
1304 | node = clear_flag(node)->p.next; |
1305 | if (!is_dummy(node)) | |
abc490a1 | 1306 | return -EPERM; |
273399de | 1307 | assert(!is_removed(node)); |
bb7b2f26 | 1308 | } while (!is_end(node)); |
4105056a MD |
1309 | /* |
1310 | * size accessed without rcu_dereference because hash table is | |
1311 | * being destroyed. | |
1312 | */ | |
1313 | size = ht->t.size; | |
abc490a1 | 1314 | /* Internal sanity check: all nodes left should be dummy */ |
4105056a | 1315 | for (order = 0; order < get_count_order_ulong(size) + 1; order++) { |
24365af7 MD |
1316 | unsigned long len; |
1317 | ||
1318 | len = !order ? 1 : 1UL << (order - 1); | |
1319 | for (i = 0; i < len; i++) { | |
f0c29ed7 | 1320 | dbg_printf("delete order %lu i %lu hash %lu\n", |
24365af7 | 1321 | order, i, |
4105056a MD |
1322 | bit_reverse_ulong(ht->t.tbl[order]->nodes[i].reverse_hash)); |
1323 | assert(is_dummy(ht->t.tbl[order]->nodes[i].next)); | |
24365af7 | 1324 | } |
4105056a | 1325 | poison_free(ht->t.tbl[order]); |
674f7a69 | 1326 | } |
abc490a1 | 1327 | return 0; |
674f7a69 MD |
1328 | } |
1329 | ||
1330 | /* | |
1331 | * Should only be called when no more concurrent readers nor writers can | |
1332 | * possibly access the table. | |
1333 | */ | |
14044b37 | 1334 | int cds_lfht_destroy(struct cds_lfht *ht) |
674f7a69 | 1335 | { |
5e28c532 MD |
1336 | int ret; |
1337 | ||
848d4088 | 1338 | /* Wait for in-flight resize operations to complete */ |
33c7c748 | 1339 | CMM_STORE_SHARED(ht->in_progress_destroy, 1); |
848d4088 MD |
1340 | while (uatomic_read(&ht->in_progress_resize)) |
1341 | poll(NULL, 0, 100); /* wait for 100ms */ | |
14044b37 | 1342 | ret = cds_lfht_delete_dummy(ht); |
abc490a1 MD |
1343 | if (ret) |
1344 | return ret; | |
df44348d | 1345 | free_per_cpu_items_count(ht->percpu_count); |
98808fb1 | 1346 | poison_free(ht); |
5e28c532 | 1347 | return ret; |
674f7a69 MD |
1348 | } |
1349 | ||
14044b37 | 1350 | void cds_lfht_count_nodes(struct cds_lfht *ht, |
273399de MD |
1351 | unsigned long *count, |
1352 | unsigned long *removed) | |
1353 | { | |
14044b37 MD |
1354 | struct cds_lfht_node *node, *next; |
1355 | struct _cds_lfht_node *lookup; | |
24365af7 | 1356 | unsigned long nr_dummy = 0; |
273399de MD |
1357 | |
1358 | *count = 0; | |
1359 | *removed = 0; | |
1360 | ||
24365af7 | 1361 | /* Count non-dummy nodes in the table */ |
4105056a | 1362 | lookup = &ht->t.tbl[0]->nodes[0]; |
14044b37 | 1363 | node = (struct cds_lfht_node *) lookup; |
273399de | 1364 | do { |
cc4fcb10 | 1365 | next = rcu_dereference(node->p.next); |
273399de | 1366 | if (is_removed(next)) { |
1b81fe1a | 1367 | assert(!is_dummy(next)); |
273399de | 1368 | (*removed)++; |
1b81fe1a | 1369 | } else if (!is_dummy(next)) |
273399de | 1370 | (*count)++; |
24365af7 MD |
1371 | else |
1372 | (nr_dummy)++; | |
273399de | 1373 | node = clear_flag(next); |
bb7b2f26 | 1374 | } while (!is_end(node)); |
f0c29ed7 | 1375 | dbg_printf("number of dummy nodes: %lu\n", nr_dummy); |
273399de MD |
1376 | } |
1377 | ||
1475579c | 1378 | /* called with resize mutex held */ |
abc490a1 | 1379 | static |
4105056a | 1380 | void _do_cds_lfht_grow(struct cds_lfht *ht, |
1475579c | 1381 | unsigned long old_size, unsigned long new_size) |
abc490a1 | 1382 | { |
1475579c | 1383 | unsigned long old_order, new_order; |
1475579c MD |
1384 | |
1385 | old_order = get_count_order_ulong(old_size) + 1; | |
1386 | new_order = get_count_order_ulong(new_size) + 1; | |
1387 | printf("resize from %lu (order %lu) to %lu (order %lu) buckets\n", | |
1388 | old_size, old_order, new_size, new_order); | |
1475579c | 1389 | assert(new_size > old_size); |
4105056a | 1390 | init_table(ht, old_order, new_order - old_order); |
abc490a1 MD |
1391 | } |
1392 | ||
1393 | /* called with resize mutex held */ | |
1394 | static | |
4105056a | 1395 | void _do_cds_lfht_shrink(struct cds_lfht *ht, |
1475579c | 1396 | unsigned long old_size, unsigned long new_size) |
464a1ec9 | 1397 | { |
1475579c | 1398 | unsigned long old_order, new_order; |
464a1ec9 | 1399 | |
cd95516d | 1400 | new_size = max(new_size, MIN_TABLE_SIZE); |
24365af7 | 1401 | old_order = get_count_order_ulong(old_size) + 1; |
24365af7 | 1402 | new_order = get_count_order_ulong(new_size) + 1; |
df44348d | 1403 | printf("resize from %lu (order %lu) to %lu (order %lu) buckets\n", |
df03fab8 | 1404 | old_size, old_order, new_size, new_order); |
1475579c | 1405 | assert(new_size < old_size); |
1475579c | 1406 | |
4105056a MD |
1407 | /* Remove and unlink all dummy nodes to remove. */ |
1408 | fini_table(ht, new_order, old_order - new_order); | |
464a1ec9 MD |
1409 | } |
1410 | ||
1475579c MD |
1411 | |
1412 | /* called with resize mutex held */ | |
1413 | static | |
1414 | void _do_cds_lfht_resize(struct cds_lfht *ht) | |
1415 | { | |
1416 | unsigned long new_size, old_size; | |
4105056a MD |
1417 | |
1418 | /* | |
1419 | * Resize table, re-do if the target size has changed under us. | |
1420 | */ | |
1421 | do { | |
1422 | ht->t.resize_initiated = 1; | |
1423 | old_size = ht->t.size; | |
1424 | new_size = CMM_LOAD_SHARED(ht->t.resize_target); | |
1425 | if (old_size < new_size) | |
1426 | _do_cds_lfht_grow(ht, old_size, new_size); | |
1427 | else if (old_size > new_size) | |
1428 | _do_cds_lfht_shrink(ht, old_size, new_size); | |
1429 | ht->t.resize_initiated = 0; | |
1430 | /* write resize_initiated before read resize_target */ | |
1431 | cmm_smp_mb(); | |
4d676753 | 1432 | } while (ht->t.size != CMM_LOAD_SHARED(ht->t.resize_target)); |
1475579c MD |
1433 | } |
1434 | ||
abc490a1 | 1435 | static |
4105056a | 1436 | unsigned long resize_target_update(struct cds_lfht *ht, unsigned long size, |
f9830efd | 1437 | int growth_order) |
464a1ec9 | 1438 | { |
4105056a MD |
1439 | return _uatomic_max(&ht->t.resize_target, |
1440 | size << growth_order); | |
464a1ec9 MD |
1441 | } |
1442 | ||
1475579c | 1443 | static |
4105056a | 1444 | void resize_target_update_count(struct cds_lfht *ht, |
b8af5011 | 1445 | unsigned long count) |
1475579c | 1446 | { |
cd95516d | 1447 | count = max(count, MIN_TABLE_SIZE); |
4105056a | 1448 | uatomic_set(&ht->t.resize_target, count); |
1475579c MD |
1449 | } |
1450 | ||
1451 | void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size) | |
464a1ec9 | 1452 | { |
4105056a MD |
1453 | resize_target_update_count(ht, new_size); |
1454 | CMM_STORE_SHARED(ht->t.resize_initiated, 1); | |
5f511391 | 1455 | ht->cds_lfht_rcu_thread_offline(); |
1475579c MD |
1456 | pthread_mutex_lock(&ht->resize_mutex); |
1457 | _do_cds_lfht_resize(ht); | |
1458 | pthread_mutex_unlock(&ht->resize_mutex); | |
5f511391 | 1459 | ht->cds_lfht_rcu_thread_online(); |
abc490a1 | 1460 | } |
464a1ec9 | 1461 | |
abc490a1 MD |
1462 | static |
1463 | void do_resize_cb(struct rcu_head *head) | |
1464 | { | |
1465 | struct rcu_resize_work *work = | |
1466 | caa_container_of(head, struct rcu_resize_work, head); | |
14044b37 | 1467 | struct cds_lfht *ht = work->ht; |
abc490a1 | 1468 | |
5f511391 | 1469 | ht->cds_lfht_rcu_thread_offline(); |
abc490a1 | 1470 | pthread_mutex_lock(&ht->resize_mutex); |
14044b37 | 1471 | _do_cds_lfht_resize(ht); |
abc490a1 | 1472 | pthread_mutex_unlock(&ht->resize_mutex); |
5f511391 | 1473 | ht->cds_lfht_rcu_thread_online(); |
98808fb1 | 1474 | poison_free(work); |
848d4088 MD |
1475 | cmm_smp_mb(); /* finish resize before decrement */ |
1476 | uatomic_dec(&ht->in_progress_resize); | |
464a1ec9 MD |
1477 | } |
1478 | ||
abc490a1 | 1479 | static |
4105056a | 1480 | void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth) |
ab7d5fc6 | 1481 | { |
abc490a1 | 1482 | struct rcu_resize_work *work; |
f9830efd | 1483 | unsigned long target_size; |
abc490a1 | 1484 | |
4105056a MD |
1485 | target_size = resize_target_update(ht, size, growth); |
1486 | /* Store resize_target before read resize_initiated */ | |
1487 | cmm_smp_mb(); | |
1488 | if (!CMM_LOAD_SHARED(ht->t.resize_initiated) && size < target_size) { | |
848d4088 MD |
1489 | uatomic_inc(&ht->in_progress_resize); |
1490 | cmm_smp_mb(); /* increment resize count before calling it */ | |
f9830efd MD |
1491 | work = malloc(sizeof(*work)); |
1492 | work->ht = ht; | |
14044b37 | 1493 | ht->cds_lfht_call_rcu(&work->head, do_resize_cb); |
4105056a | 1494 | CMM_STORE_SHARED(ht->t.resize_initiated, 1); |
f9830efd | 1495 | } |
ab7d5fc6 | 1496 | } |
3171717f | 1497 | |
f8994aee MD |
1498 | #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) |
1499 | ||
3171717f | 1500 | static |
4105056a | 1501 | void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size, |
3171717f MD |
1502 | unsigned long count) |
1503 | { | |
1504 | struct rcu_resize_work *work; | |
3171717f | 1505 | |
b8af5011 MD |
1506 | if (!(ht->flags & CDS_LFHT_AUTO_RESIZE)) |
1507 | return; | |
4105056a MD |
1508 | resize_target_update_count(ht, count); |
1509 | /* Store resize_target before read resize_initiated */ | |
1510 | cmm_smp_mb(); | |
1511 | if (!CMM_LOAD_SHARED(ht->t.resize_initiated)) { | |
3171717f MD |
1512 | uatomic_inc(&ht->in_progress_resize); |
1513 | cmm_smp_mb(); /* increment resize count before calling it */ | |
1514 | work = malloc(sizeof(*work)); | |
1515 | work->ht = ht; | |
1516 | ht->cds_lfht_call_rcu(&work->head, do_resize_cb); | |
4105056a | 1517 | CMM_STORE_SHARED(ht->t.resize_initiated, 1); |
3171717f MD |
1518 | } |
1519 | } | |
f8994aee MD |
1520 | |
1521 | #endif |