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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 | ||
b7d619b0 MD |
180 | /* |
181 | * Minimum number of dummy nodes to touch per thread to parallelize grow/shrink. | |
182 | */ | |
6083a889 MD |
183 | #define MIN_PARTITION_PER_THREAD_ORDER 12 |
184 | #define MIN_PARTITION_PER_THREAD (1UL << MIN_PARTITION_PER_THREAD_ORDER) | |
b7d619b0 | 185 | |
4105056a MD |
186 | #ifndef min |
187 | #define min(a, b) ((a) < (b) ? (a) : (b)) | |
188 | #endif | |
189 | ||
abc490a1 MD |
190 | #ifndef max |
191 | #define max(a, b) ((a) > (b) ? (a) : (b)) | |
192 | #endif | |
2ed95849 | 193 | |
d95bd160 MD |
194 | /* |
195 | * The removed flag needs to be updated atomically with the pointer. | |
196 | * The dummy flag does not require to be updated atomically with the | |
197 | * pointer, but it is added as a pointer low bit flag to save space. | |
198 | */ | |
d37166c6 | 199 | #define REMOVED_FLAG (1UL << 0) |
f5596c94 MD |
200 | #define DUMMY_FLAG (1UL << 1) |
201 | #define FLAGS_MASK ((1UL << 2) - 1) | |
d37166c6 | 202 | |
bb7b2f26 | 203 | /* Value of the end pointer. Should not interact with flags. */ |
f9c80341 | 204 | #define END_VALUE NULL |
bb7b2f26 | 205 | |
df44348d | 206 | struct ht_items_count { |
860d07e8 | 207 | unsigned long add, del; |
df44348d MD |
208 | } __attribute__((aligned(CAA_CACHE_LINE_SIZE))); |
209 | ||
1475579c MD |
210 | struct rcu_level { |
211 | struct rcu_head head; | |
212 | struct _cds_lfht_node nodes[0]; | |
213 | }; | |
214 | ||
395270b6 | 215 | struct rcu_table { |
4105056a | 216 | unsigned long size; /* always a power of 2, shared (RCU) */ |
f9830efd | 217 | unsigned long resize_target; |
11519af6 | 218 | int resize_initiated; |
4105056a | 219 | struct rcu_level *tbl[MAX_TABLE_ORDER]; |
395270b6 MD |
220 | }; |
221 | ||
14044b37 | 222 | struct cds_lfht { |
4105056a | 223 | struct rcu_table t; |
14044b37 MD |
224 | cds_lfht_hash_fct hash_fct; |
225 | cds_lfht_compare_fct compare_fct; | |
732ad076 | 226 | unsigned long hash_seed; |
b8af5011 | 227 | int flags; |
5f511391 MD |
228 | /* |
229 | * We need to put the work threads offline (QSBR) when taking this | |
230 | * mutex, because we use synchronize_rcu within this mutex critical | |
231 | * section, which waits on read-side critical sections, and could | |
232 | * therefore cause grace-period deadlock if we hold off RCU G.P. | |
233 | * completion. | |
234 | */ | |
464a1ec9 | 235 | pthread_mutex_t resize_mutex; /* resize mutex: add/del mutex */ |
33c7c748 | 236 | unsigned int in_progress_resize, in_progress_destroy; |
14044b37 | 237 | void (*cds_lfht_call_rcu)(struct rcu_head *head, |
abc490a1 | 238 | void (*func)(struct rcu_head *head)); |
1475579c | 239 | void (*cds_lfht_synchronize_rcu)(void); |
01dbfa62 MD |
240 | void (*cds_lfht_rcu_read_lock)(void); |
241 | void (*cds_lfht_rcu_read_unlock)(void); | |
5f511391 MD |
242 | void (*cds_lfht_rcu_thread_offline)(void); |
243 | void (*cds_lfht_rcu_thread_online)(void); | |
b7d619b0 MD |
244 | void (*cds_lfht_rcu_register_thread)(void); |
245 | void (*cds_lfht_rcu_unregister_thread)(void); | |
246 | pthread_attr_t *resize_attr; /* Resize threads attributes */ | |
df44348d MD |
247 | unsigned long count; /* global approximate item count */ |
248 | struct ht_items_count *percpu_count; /* per-cpu item count */ | |
2ed95849 MD |
249 | }; |
250 | ||
abc490a1 MD |
251 | struct rcu_resize_work { |
252 | struct rcu_head head; | |
14044b37 | 253 | struct cds_lfht *ht; |
abc490a1 | 254 | }; |
2ed95849 | 255 | |
b7d619b0 MD |
256 | struct partition_resize_work { |
257 | struct rcu_head head; | |
258 | struct cds_lfht *ht; | |
259 | unsigned long i, start, len; | |
260 | void (*fct)(struct cds_lfht *ht, unsigned long i, | |
261 | unsigned long start, unsigned long len); | |
262 | }; | |
263 | ||
76a73da8 MD |
264 | static |
265 | struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht, | |
266 | unsigned long size, | |
267 | struct cds_lfht_node *node, | |
268 | int unique, int dummy); | |
269 | ||
abc490a1 MD |
270 | /* |
271 | * Algorithm to reverse bits in a word by lookup table, extended to | |
272 | * 64-bit words. | |
f9830efd | 273 | * Source: |
abc490a1 | 274 | * http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable |
f9830efd | 275 | * Originally from Public Domain. |
abc490a1 MD |
276 | */ |
277 | ||
278 | static const uint8_t BitReverseTable256[256] = | |
2ed95849 | 279 | { |
abc490a1 MD |
280 | #define R2(n) (n), (n) + 2*64, (n) + 1*64, (n) + 3*64 |
281 | #define R4(n) R2(n), R2((n) + 2*16), R2((n) + 1*16), R2((n) + 3*16) | |
282 | #define R6(n) R4(n), R4((n) + 2*4 ), R4((n) + 1*4 ), R4((n) + 3*4 ) | |
283 | R6(0), R6(2), R6(1), R6(3) | |
284 | }; | |
285 | #undef R2 | |
286 | #undef R4 | |
287 | #undef R6 | |
2ed95849 | 288 | |
abc490a1 MD |
289 | static |
290 | uint8_t bit_reverse_u8(uint8_t v) | |
291 | { | |
292 | return BitReverseTable256[v]; | |
293 | } | |
ab7d5fc6 | 294 | |
abc490a1 MD |
295 | static __attribute__((unused)) |
296 | uint32_t bit_reverse_u32(uint32_t v) | |
297 | { | |
298 | return ((uint32_t) bit_reverse_u8(v) << 24) | | |
299 | ((uint32_t) bit_reverse_u8(v >> 8) << 16) | | |
300 | ((uint32_t) bit_reverse_u8(v >> 16) << 8) | | |
301 | ((uint32_t) bit_reverse_u8(v >> 24)); | |
2ed95849 MD |
302 | } |
303 | ||
abc490a1 MD |
304 | static __attribute__((unused)) |
305 | uint64_t bit_reverse_u64(uint64_t v) | |
2ed95849 | 306 | { |
abc490a1 MD |
307 | return ((uint64_t) bit_reverse_u8(v) << 56) | |
308 | ((uint64_t) bit_reverse_u8(v >> 8) << 48) | | |
309 | ((uint64_t) bit_reverse_u8(v >> 16) << 40) | | |
310 | ((uint64_t) bit_reverse_u8(v >> 24) << 32) | | |
311 | ((uint64_t) bit_reverse_u8(v >> 32) << 24) | | |
312 | ((uint64_t) bit_reverse_u8(v >> 40) << 16) | | |
313 | ((uint64_t) bit_reverse_u8(v >> 48) << 8) | | |
314 | ((uint64_t) bit_reverse_u8(v >> 56)); | |
315 | } | |
316 | ||
317 | static | |
318 | unsigned long bit_reverse_ulong(unsigned long v) | |
319 | { | |
320 | #if (CAA_BITS_PER_LONG == 32) | |
321 | return bit_reverse_u32(v); | |
322 | #else | |
323 | return bit_reverse_u64(v); | |
324 | #endif | |
325 | } | |
326 | ||
f9830efd | 327 | /* |
24365af7 MD |
328 | * fls: returns the position of the most significant bit. |
329 | * Returns 0 if no bit is set, else returns the position of the most | |
330 | * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit). | |
f9830efd | 331 | */ |
24365af7 MD |
332 | #if defined(__i386) || defined(__x86_64) |
333 | static inline | |
334 | unsigned int fls_u32(uint32_t x) | |
f9830efd | 335 | { |
24365af7 MD |
336 | int r; |
337 | ||
338 | asm("bsrl %1,%0\n\t" | |
339 | "jnz 1f\n\t" | |
340 | "movl $-1,%0\n\t" | |
341 | "1:\n\t" | |
342 | : "=r" (r) : "rm" (x)); | |
343 | return r + 1; | |
344 | } | |
345 | #define HAS_FLS_U32 | |
346 | #endif | |
347 | ||
348 | #if defined(__x86_64) | |
349 | static inline | |
350 | unsigned int fls_u64(uint64_t x) | |
351 | { | |
352 | long r; | |
353 | ||
354 | asm("bsrq %1,%0\n\t" | |
355 | "jnz 1f\n\t" | |
356 | "movq $-1,%0\n\t" | |
357 | "1:\n\t" | |
358 | : "=r" (r) : "rm" (x)); | |
359 | return r + 1; | |
360 | } | |
361 | #define HAS_FLS_U64 | |
362 | #endif | |
363 | ||
364 | #ifndef HAS_FLS_U64 | |
365 | static __attribute__((unused)) | |
366 | unsigned int fls_u64(uint64_t x) | |
367 | { | |
368 | unsigned int r = 64; | |
369 | ||
370 | if (!x) | |
371 | return 0; | |
372 | ||
373 | if (!(x & 0xFFFFFFFF00000000ULL)) { | |
374 | x <<= 32; | |
375 | r -= 32; | |
376 | } | |
377 | if (!(x & 0xFFFF000000000000ULL)) { | |
378 | x <<= 16; | |
379 | r -= 16; | |
380 | } | |
381 | if (!(x & 0xFF00000000000000ULL)) { | |
382 | x <<= 8; | |
383 | r -= 8; | |
384 | } | |
385 | if (!(x & 0xF000000000000000ULL)) { | |
386 | x <<= 4; | |
387 | r -= 4; | |
388 | } | |
389 | if (!(x & 0xC000000000000000ULL)) { | |
390 | x <<= 2; | |
391 | r -= 2; | |
392 | } | |
393 | if (!(x & 0x8000000000000000ULL)) { | |
394 | x <<= 1; | |
395 | r -= 1; | |
396 | } | |
397 | return r; | |
398 | } | |
399 | #endif | |
400 | ||
401 | #ifndef HAS_FLS_U32 | |
402 | static __attribute__((unused)) | |
403 | unsigned int fls_u32(uint32_t x) | |
404 | { | |
405 | unsigned int r = 32; | |
f9830efd | 406 | |
24365af7 MD |
407 | if (!x) |
408 | return 0; | |
409 | if (!(x & 0xFFFF0000U)) { | |
410 | x <<= 16; | |
411 | r -= 16; | |
412 | } | |
413 | if (!(x & 0xFF000000U)) { | |
414 | x <<= 8; | |
415 | r -= 8; | |
416 | } | |
417 | if (!(x & 0xF0000000U)) { | |
418 | x <<= 4; | |
419 | r -= 4; | |
420 | } | |
421 | if (!(x & 0xC0000000U)) { | |
422 | x <<= 2; | |
423 | r -= 2; | |
424 | } | |
425 | if (!(x & 0x80000000U)) { | |
426 | x <<= 1; | |
427 | r -= 1; | |
428 | } | |
429 | return r; | |
430 | } | |
431 | #endif | |
432 | ||
433 | unsigned int fls_ulong(unsigned long x) | |
f9830efd | 434 | { |
24365af7 MD |
435 | #if (CAA_BITS_PER_lONG == 32) |
436 | return fls_u32(x); | |
437 | #else | |
438 | return fls_u64(x); | |
439 | #endif | |
440 | } | |
f9830efd | 441 | |
24365af7 MD |
442 | int get_count_order_u32(uint32_t x) |
443 | { | |
444 | int order; | |
445 | ||
446 | order = fls_u32(x) - 1; | |
447 | if (x & (x - 1)) | |
448 | order++; | |
449 | return order; | |
450 | } | |
451 | ||
452 | int get_count_order_ulong(unsigned long x) | |
453 | { | |
454 | int order; | |
455 | ||
456 | order = fls_ulong(x) - 1; | |
457 | if (x & (x - 1)) | |
458 | order++; | |
459 | return order; | |
f9830efd MD |
460 | } |
461 | ||
98808fb1 MD |
462 | #ifdef POISON_FREE |
463 | #define poison_free(ptr) \ | |
464 | do { \ | |
465 | memset(ptr, 0x42, sizeof(*(ptr))); \ | |
466 | free(ptr); \ | |
467 | } while (0) | |
468 | #else | |
469 | #define poison_free(ptr) free(ptr) | |
470 | #endif | |
471 | ||
f9830efd | 472 | static |
4105056a | 473 | void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth); |
f9830efd | 474 | |
df44348d MD |
475 | /* |
476 | * If the sched_getcpu() and sysconf(_SC_NPROCESSORS_CONF) calls are | |
477 | * available, then we support hash table item accounting. | |
478 | * In the unfortunate event the number of CPUs reported would be | |
479 | * inaccurate, we use modulo arithmetic on the number of CPUs we got. | |
480 | */ | |
df44348d MD |
481 | #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) |
482 | ||
f8994aee | 483 | static |
4105056a | 484 | void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size, |
f8994aee MD |
485 | unsigned long count); |
486 | ||
df44348d MD |
487 | static long nr_cpus_mask = -1; |
488 | ||
489 | static | |
490 | struct ht_items_count *alloc_per_cpu_items_count(void) | |
491 | { | |
492 | struct ht_items_count *count; | |
493 | ||
494 | switch (nr_cpus_mask) { | |
495 | case -2: | |
496 | return NULL; | |
497 | case -1: | |
498 | { | |
499 | long maxcpus; | |
500 | ||
501 | maxcpus = sysconf(_SC_NPROCESSORS_CONF); | |
502 | if (maxcpus <= 0) { | |
503 | nr_cpus_mask = -2; | |
504 | return NULL; | |
505 | } | |
506 | /* | |
507 | * round up number of CPUs to next power of two, so we | |
508 | * can use & for modulo. | |
509 | */ | |
510 | maxcpus = 1UL << get_count_order_ulong(maxcpus); | |
511 | nr_cpus_mask = maxcpus - 1; | |
512 | } | |
513 | /* Fall-through */ | |
514 | default: | |
515 | return calloc(nr_cpus_mask + 1, sizeof(*count)); | |
516 | } | |
517 | } | |
518 | ||
519 | static | |
520 | void free_per_cpu_items_count(struct ht_items_count *count) | |
521 | { | |
98808fb1 | 522 | poison_free(count); |
df44348d MD |
523 | } |
524 | ||
525 | static | |
526 | int ht_get_cpu(void) | |
527 | { | |
528 | int cpu; | |
529 | ||
530 | assert(nr_cpus_mask >= 0); | |
531 | cpu = sched_getcpu(); | |
532 | if (unlikely(cpu < 0)) | |
533 | return cpu; | |
534 | else | |
535 | return cpu & nr_cpus_mask; | |
536 | } | |
537 | ||
538 | static | |
4105056a | 539 | void ht_count_add(struct cds_lfht *ht, unsigned long size) |
df44348d | 540 | { |
3171717f | 541 | unsigned long percpu_count; |
df44348d MD |
542 | int cpu; |
543 | ||
544 | if (unlikely(!ht->percpu_count)) | |
3171717f | 545 | return; |
df44348d MD |
546 | cpu = ht_get_cpu(); |
547 | if (unlikely(cpu < 0)) | |
3171717f MD |
548 | return; |
549 | percpu_count = uatomic_add_return(&ht->percpu_count[cpu].add, 1); | |
df44348d MD |
550 | if (unlikely(!(percpu_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) { |
551 | unsigned long count; | |
552 | ||
553 | dbg_printf("add percpu %lu\n", percpu_count); | |
554 | count = uatomic_add_return(&ht->count, | |
555 | 1UL << COUNT_COMMIT_ORDER); | |
556 | /* If power of 2 */ | |
557 | if (!(count & (count - 1))) { | |
4105056a | 558 | if ((count >> CHAIN_LEN_RESIZE_THRESHOLD) < size) |
f8994aee MD |
559 | return; |
560 | dbg_printf("add set global %lu\n", count); | |
4105056a | 561 | cds_lfht_resize_lazy_count(ht, size, |
6ea6bc67 | 562 | count >> (CHAIN_LEN_TARGET - 1)); |
df44348d MD |
563 | } |
564 | } | |
565 | } | |
566 | ||
567 | static | |
860d07e8 | 568 | void ht_count_del(struct cds_lfht *ht, unsigned long size) |
df44348d MD |
569 | { |
570 | unsigned long percpu_count; | |
3171717f | 571 | int cpu; |
df44348d | 572 | |
3171717f MD |
573 | if (unlikely(!ht->percpu_count)) |
574 | return; | |
575 | cpu = ht_get_cpu(); | |
576 | if (unlikely(cpu < 0)) | |
577 | return; | |
860d07e8 | 578 | percpu_count = uatomic_add_return(&ht->percpu_count[cpu].del, -1); |
df44348d MD |
579 | if (unlikely(!(percpu_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) { |
580 | unsigned long count; | |
581 | ||
860d07e8 | 582 | dbg_printf("del percpu %lu\n", percpu_count); |
df44348d | 583 | count = uatomic_add_return(&ht->count, |
3171717f | 584 | -(1UL << COUNT_COMMIT_ORDER)); |
df44348d MD |
585 | /* If power of 2 */ |
586 | if (!(count & (count - 1))) { | |
4105056a | 587 | if ((count >> CHAIN_LEN_RESIZE_THRESHOLD) >= size) |
f8994aee | 588 | return; |
860d07e8 | 589 | dbg_printf("del set global %lu\n", count); |
4105056a | 590 | cds_lfht_resize_lazy_count(ht, size, |
6ea6bc67 | 591 | count >> (CHAIN_LEN_TARGET - 1)); |
df44348d MD |
592 | } |
593 | } | |
594 | } | |
595 | ||
596 | #else /* #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */ | |
597 | ||
598 | static const long nr_cpus_mask = -1; | |
599 | ||
600 | static | |
601 | struct ht_items_count *alloc_per_cpu_items_count(void) | |
602 | { | |
603 | return NULL; | |
604 | } | |
605 | ||
606 | static | |
607 | void free_per_cpu_items_count(struct ht_items_count *count) | |
608 | { | |
609 | } | |
610 | ||
611 | static | |
4105056a | 612 | void ht_count_add(struct cds_lfht *ht, unsigned long size) |
df44348d MD |
613 | { |
614 | } | |
615 | ||
616 | static | |
860d07e8 | 617 | void ht_count_del(struct cds_lfht *ht, unsigned long size) |
df44348d MD |
618 | { |
619 | } | |
620 | ||
621 | #endif /* #else #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */ | |
622 | ||
623 | ||
f9830efd | 624 | static |
4105056a | 625 | void check_resize(struct cds_lfht *ht, unsigned long size, uint32_t chain_len) |
f9830efd | 626 | { |
f8994aee MD |
627 | unsigned long count; |
628 | ||
b8af5011 MD |
629 | if (!(ht->flags & CDS_LFHT_AUTO_RESIZE)) |
630 | return; | |
f8994aee MD |
631 | count = uatomic_read(&ht->count); |
632 | /* | |
633 | * Use bucket-local length for small table expand and for | |
634 | * environments lacking per-cpu data support. | |
635 | */ | |
636 | if (count >= (1UL << COUNT_COMMIT_ORDER)) | |
637 | return; | |
24365af7 | 638 | if (chain_len > 100) |
f0c29ed7 | 639 | dbg_printf("WARNING: large chain length: %u.\n", |
24365af7 | 640 | chain_len); |
3390d470 | 641 | if (chain_len >= CHAIN_LEN_RESIZE_THRESHOLD) |
4105056a | 642 | cds_lfht_resize_lazy(ht, size, |
01370f0b | 643 | get_count_order_u32(chain_len - (CHAIN_LEN_TARGET - 1))); |
f9830efd MD |
644 | } |
645 | ||
abc490a1 | 646 | static |
14044b37 | 647 | struct cds_lfht_node *clear_flag(struct cds_lfht_node *node) |
abc490a1 | 648 | { |
14044b37 | 649 | return (struct cds_lfht_node *) (((unsigned long) node) & ~FLAGS_MASK); |
abc490a1 MD |
650 | } |
651 | ||
652 | static | |
14044b37 | 653 | int is_removed(struct cds_lfht_node *node) |
abc490a1 | 654 | { |
d37166c6 | 655 | return ((unsigned long) node) & REMOVED_FLAG; |
abc490a1 MD |
656 | } |
657 | ||
658 | static | |
14044b37 | 659 | struct cds_lfht_node *flag_removed(struct cds_lfht_node *node) |
abc490a1 | 660 | { |
14044b37 | 661 | return (struct cds_lfht_node *) (((unsigned long) node) | REMOVED_FLAG); |
abc490a1 MD |
662 | } |
663 | ||
f5596c94 | 664 | static |
14044b37 | 665 | int is_dummy(struct cds_lfht_node *node) |
f5596c94 MD |
666 | { |
667 | return ((unsigned long) node) & DUMMY_FLAG; | |
668 | } | |
669 | ||
670 | static | |
14044b37 | 671 | struct cds_lfht_node *flag_dummy(struct cds_lfht_node *node) |
f5596c94 | 672 | { |
14044b37 | 673 | return (struct cds_lfht_node *) (((unsigned long) node) | DUMMY_FLAG); |
f5596c94 | 674 | } |
bb7b2f26 MD |
675 | |
676 | static | |
677 | struct cds_lfht_node *get_end(void) | |
678 | { | |
679 | return (struct cds_lfht_node *) END_VALUE; | |
680 | } | |
681 | ||
682 | static | |
683 | int is_end(struct cds_lfht_node *node) | |
684 | { | |
685 | return clear_flag(node) == (struct cds_lfht_node *) END_VALUE; | |
686 | } | |
687 | ||
abc490a1 | 688 | static |
f9830efd | 689 | unsigned long _uatomic_max(unsigned long *ptr, unsigned long v) |
abc490a1 MD |
690 | { |
691 | unsigned long old1, old2; | |
692 | ||
693 | old1 = uatomic_read(ptr); | |
694 | do { | |
695 | old2 = old1; | |
696 | if (old2 >= v) | |
f9830efd | 697 | return old2; |
abc490a1 | 698 | } while ((old1 = uatomic_cmpxchg(ptr, old2, v)) != old2); |
f9830efd | 699 | return v; |
abc490a1 MD |
700 | } |
701 | ||
1475579c MD |
702 | static |
703 | void cds_lfht_free_level(struct rcu_head *head) | |
704 | { | |
705 | struct rcu_level *l = | |
706 | caa_container_of(head, struct rcu_level, head); | |
98808fb1 | 707 | poison_free(l); |
1475579c MD |
708 | } |
709 | ||
273399de MD |
710 | /* |
711 | * Remove all logically deleted nodes from a bucket up to a certain node key. | |
712 | */ | |
713 | static | |
f9c80341 | 714 | void _cds_lfht_gc_bucket(struct cds_lfht_node *dummy, struct cds_lfht_node *node) |
273399de | 715 | { |
14044b37 | 716 | struct cds_lfht_node *iter_prev, *iter, *next, *new_next; |
273399de | 717 | |
c90201ac MD |
718 | assert(!is_dummy(dummy)); |
719 | assert(!is_removed(dummy)); | |
720 | assert(!is_dummy(node)); | |
721 | assert(!is_removed(node)); | |
273399de MD |
722 | for (;;) { |
723 | iter_prev = dummy; | |
724 | /* We can always skip the dummy node initially */ | |
cc4fcb10 MD |
725 | iter = rcu_dereference(iter_prev->p.next); |
726 | assert(iter_prev->p.reverse_hash <= node->p.reverse_hash); | |
bd4db153 MD |
727 | /* |
728 | * We should never be called with dummy (start of chain) | |
729 | * and logically removed node (end of path compression | |
730 | * marker) being the actual same node. This would be a | |
731 | * bug in the algorithm implementation. | |
732 | */ | |
733 | assert(dummy != node); | |
273399de | 734 | for (;;) { |
bb7b2f26 | 735 | if (unlikely(is_end(iter))) |
f9c80341 | 736 | return; |
76412f24 | 737 | if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash)) |
f9c80341 | 738 | return; |
cc4fcb10 | 739 | next = rcu_dereference(clear_flag(iter)->p.next); |
76412f24 | 740 | if (likely(is_removed(next))) |
273399de | 741 | break; |
b453eae1 | 742 | iter_prev = clear_flag(iter); |
273399de MD |
743 | iter = next; |
744 | } | |
745 | assert(!is_removed(iter)); | |
f5596c94 MD |
746 | if (is_dummy(iter)) |
747 | new_next = flag_dummy(clear_flag(next)); | |
748 | else | |
749 | new_next = clear_flag(next); | |
750 | (void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next); | |
273399de | 751 | } |
f9c80341 | 752 | return; |
273399de MD |
753 | } |
754 | ||
abc490a1 | 755 | static |
4105056a MD |
756 | struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht, |
757 | unsigned long size, | |
758 | struct cds_lfht_node *node, | |
759 | int unique, int dummy) | |
abc490a1 | 760 | { |
14044b37 | 761 | struct cds_lfht_node *iter_prev, *iter, *next, *new_node, *new_next, |
f5596c94 | 762 | *dummy_node; |
14044b37 | 763 | struct _cds_lfht_node *lookup; |
24365af7 | 764 | unsigned long hash, index, order; |
abc490a1 | 765 | |
c90201ac MD |
766 | assert(!is_dummy(node)); |
767 | assert(!is_removed(node)); | |
4105056a | 768 | if (!size) { |
f5596c94 | 769 | assert(dummy); |
bb7b2f26 | 770 | node->p.next = flag_dummy(get_end()); |
18117871 MD |
771 | return node; /* Initial first add (head) */ |
772 | } | |
cc4fcb10 | 773 | hash = bit_reverse_ulong(node->p.reverse_hash); |
abc490a1 | 774 | for (;;) { |
f9830efd | 775 | uint32_t chain_len = 0; |
abc490a1 | 776 | |
11519af6 MD |
777 | /* |
778 | * iter_prev points to the non-removed node prior to the | |
779 | * insert location. | |
11519af6 | 780 | */ |
4105056a | 781 | index = hash & (size - 1); |
24365af7 | 782 | order = get_count_order_ulong(index + 1); |
4105056a | 783 | lookup = &ht->t.tbl[order]->nodes[index & ((!order ? 0 : (1UL << (order - 1))) - 1)]; |
14044b37 | 784 | iter_prev = (struct cds_lfht_node *) lookup; |
11519af6 | 785 | /* We can always skip the dummy node initially */ |
cc4fcb10 MD |
786 | iter = rcu_dereference(iter_prev->p.next); |
787 | assert(iter_prev->p.reverse_hash <= node->p.reverse_hash); | |
abc490a1 | 788 | for (;;) { |
bb7b2f26 | 789 | if (unlikely(is_end(iter))) |
273399de | 790 | goto insert; |
76412f24 | 791 | if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash)) |
273399de | 792 | goto insert; |
cc4fcb10 | 793 | next = rcu_dereference(clear_flag(iter)->p.next); |
76412f24 | 794 | if (unlikely(is_removed(next))) |
9dba85be | 795 | goto gc_node; |
e43f23f8 | 796 | if (unique |
1b81fe1a | 797 | && !is_dummy(next) |
e43f23f8 MD |
798 | && !ht->compare_fct(node->key, node->key_len, |
799 | clear_flag(iter)->key, | |
800 | clear_flag(iter)->key_len)) | |
18117871 | 801 | return clear_flag(iter); |
11519af6 | 802 | /* Only account for identical reverse hash once */ |
24365af7 MD |
803 | if (iter_prev->p.reverse_hash != clear_flag(iter)->p.reverse_hash |
804 | && !is_dummy(next)) | |
4105056a | 805 | check_resize(ht, size, ++chain_len); |
11519af6 | 806 | iter_prev = clear_flag(iter); |
273399de | 807 | iter = next; |
abc490a1 | 808 | } |
273399de | 809 | insert: |
7ec59d3b | 810 | assert(node != clear_flag(iter)); |
11519af6 | 811 | assert(!is_removed(iter_prev)); |
c90201ac | 812 | assert(!is_removed(iter)); |
f000907d | 813 | assert(iter_prev != node); |
f9c80341 | 814 | if (!dummy) |
1b81fe1a | 815 | node->p.next = clear_flag(iter); |
f9c80341 MD |
816 | else |
817 | node->p.next = flag_dummy(clear_flag(iter)); | |
f5596c94 MD |
818 | if (is_dummy(iter)) |
819 | new_node = flag_dummy(node); | |
820 | else | |
821 | new_node = node; | |
cc4fcb10 | 822 | if (uatomic_cmpxchg(&iter_prev->p.next, iter, |
f5596c94 | 823 | new_node) != iter) |
273399de | 824 | continue; /* retry */ |
11519af6 | 825 | else |
273399de | 826 | goto gc_end; |
9dba85be MD |
827 | gc_node: |
828 | assert(!is_removed(iter)); | |
f5596c94 MD |
829 | if (is_dummy(iter)) |
830 | new_next = flag_dummy(clear_flag(next)); | |
831 | else | |
832 | new_next = clear_flag(next); | |
833 | (void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next); | |
273399de | 834 | /* retry */ |
464a1ec9 | 835 | } |
273399de MD |
836 | gc_end: |
837 | /* Garbage collect logically removed nodes in the bucket */ | |
4105056a | 838 | index = hash & (size - 1); |
24365af7 | 839 | order = get_count_order_ulong(index + 1); |
4105056a | 840 | lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1)) - 1))]; |
14044b37 | 841 | dummy_node = (struct cds_lfht_node *) lookup; |
f9c80341 | 842 | _cds_lfht_gc_bucket(dummy_node, node); |
18117871 | 843 | return node; |
abc490a1 | 844 | } |
464a1ec9 | 845 | |
abc490a1 | 846 | static |
860d07e8 | 847 | int _cds_lfht_del(struct cds_lfht *ht, unsigned long size, |
4105056a MD |
848 | struct cds_lfht_node *node, |
849 | int dummy_removal) | |
abc490a1 | 850 | { |
14044b37 MD |
851 | struct cds_lfht_node *dummy, *next, *old; |
852 | struct _cds_lfht_node *lookup; | |
abc490a1 | 853 | int flagged = 0; |
24365af7 | 854 | unsigned long hash, index, order; |
5e28c532 | 855 | |
7ec59d3b | 856 | /* logically delete the node */ |
c90201ac MD |
857 | assert(!is_dummy(node)); |
858 | assert(!is_removed(node)); | |
cc4fcb10 | 859 | old = rcu_dereference(node->p.next); |
7ec59d3b MD |
860 | do { |
861 | next = old; | |
76412f24 | 862 | if (unlikely(is_removed(next))) |
7ec59d3b | 863 | goto end; |
1475579c MD |
864 | if (dummy_removal) |
865 | assert(is_dummy(next)); | |
866 | else | |
867 | assert(!is_dummy(next)); | |
cc4fcb10 | 868 | old = uatomic_cmpxchg(&node->p.next, next, |
7ec59d3b MD |
869 | flag_removed(next)); |
870 | } while (old != next); | |
871 | ||
872 | /* We performed the (logical) deletion. */ | |
873 | flagged = 1; | |
874 | ||
875 | /* | |
876 | * Ensure that the node is not visible to readers anymore: lookup for | |
273399de MD |
877 | * the node, and remove it (along with any other logically removed node) |
878 | * if found. | |
11519af6 | 879 | */ |
cc4fcb10 | 880 | hash = bit_reverse_ulong(node->p.reverse_hash); |
4105056a MD |
881 | assert(size > 0); |
882 | index = hash & (size - 1); | |
24365af7 | 883 | order = get_count_order_ulong(index + 1); |
4105056a | 884 | lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1)) - 1))]; |
14044b37 | 885 | dummy = (struct cds_lfht_node *) lookup; |
f9c80341 | 886 | _cds_lfht_gc_bucket(dummy, node); |
2ed95849 | 887 | end: |
11519af6 MD |
888 | /* |
889 | * Only the flagging action indicated that we (and no other) | |
890 | * removed the node from the hash. | |
891 | */ | |
7ec59d3b | 892 | if (flagged) { |
cc4fcb10 | 893 | assert(is_removed(rcu_dereference(node->p.next))); |
11519af6 | 894 | return 0; |
7ec59d3b | 895 | } else |
11519af6 | 896 | return -ENOENT; |
abc490a1 | 897 | } |
2ed95849 | 898 | |
b7d619b0 MD |
899 | static |
900 | void *partition_resize_thread(void *arg) | |
901 | { | |
902 | struct partition_resize_work *work = arg; | |
903 | ||
904 | work->ht->cds_lfht_rcu_register_thread(); | |
905 | work->fct(work->ht, work->i, work->start, work->len); | |
906 | work->ht->cds_lfht_rcu_unregister_thread(); | |
907 | return NULL; | |
908 | } | |
909 | ||
910 | static | |
911 | void partition_resize_helper(struct cds_lfht *ht, unsigned long i, | |
912 | unsigned long len, | |
913 | void (*fct)(struct cds_lfht *ht, unsigned long i, | |
914 | unsigned long start, unsigned long len)) | |
915 | { | |
916 | unsigned long partition_len; | |
917 | struct partition_resize_work *work; | |
6083a889 MD |
918 | int thread, ret; |
919 | unsigned long nr_threads; | |
b7d619b0 MD |
920 | pthread_t *thread_id; |
921 | ||
6083a889 MD |
922 | /* |
923 | * Note: nr_cpus_mask + 1 is always power of 2. | |
924 | * We spawn just the number of threads we need to satisfy the minimum | |
925 | * partition size, up to the number of CPUs in the system. | |
926 | */ | |
927 | nr_threads = min(nr_cpus_mask + 1, | |
928 | len >> MIN_PARTITION_PER_THREAD_ORDER); | |
929 | partition_len = len >> get_count_order_ulong(nr_threads); | |
930 | work = calloc(nr_threads, sizeof(*work)); | |
931 | thread_id = calloc(nr_threads, sizeof(*thread_id)); | |
b7d619b0 | 932 | assert(work); |
6083a889 MD |
933 | for (thread = 0; thread < nr_threads; thread++) { |
934 | work[thread].ht = ht; | |
935 | work[thread].i = i; | |
936 | work[thread].len = partition_len; | |
937 | work[thread].start = thread * partition_len; | |
938 | work[thread].fct = fct; | |
939 | ret = pthread_create(&thread_id[thread], ht->resize_attr, | |
940 | partition_resize_thread, &work[thread]); | |
b7d619b0 MD |
941 | assert(!ret); |
942 | } | |
6083a889 MD |
943 | for (thread = 0; thread < nr_threads; thread++) { |
944 | ret = pthread_join(thread_id[thread], NULL); | |
b7d619b0 MD |
945 | assert(!ret); |
946 | } | |
947 | free(work); | |
948 | free(thread_id); | |
949 | } | |
950 | ||
e8de508e MD |
951 | /* |
952 | * Holding RCU read lock to protect _cds_lfht_add against memory | |
953 | * reclaim that could be performed by other call_rcu worker threads (ABA | |
954 | * problem). | |
9ee0fc9a | 955 | * |
b7d619b0 | 956 | * When we reach a certain length, we can split this population phase over |
9ee0fc9a MD |
957 | * many worker threads, based on the number of CPUs available in the system. |
958 | * This should therefore take care of not having the expand lagging behind too | |
959 | * many concurrent insertion threads by using the scheduler's ability to | |
960 | * schedule dummy node population fairly with insertions. | |
e8de508e | 961 | */ |
4105056a | 962 | static |
b7d619b0 MD |
963 | void init_table_populate_partition(struct cds_lfht *ht, unsigned long i, |
964 | unsigned long start, unsigned long len) | |
4105056a MD |
965 | { |
966 | unsigned long j; | |
967 | ||
968 | ht->cds_lfht_rcu_read_lock(); | |
b7d619b0 | 969 | for (j = start; j < start + len; j++) { |
4105056a MD |
970 | struct cds_lfht_node *new_node = |
971 | (struct cds_lfht_node *) &ht->t.tbl[i]->nodes[j]; | |
972 | ||
dc1da8f6 | 973 | dbg_printf("init populate: i %lu j %lu hash %lu\n", |
4105056a | 974 | i, j, !i ? 0 : (1UL << (i - 1)) + j); |
dc1da8f6 MD |
975 | new_node->p.reverse_hash = |
976 | bit_reverse_ulong(!i ? 0 : (1UL << (i - 1)) + j); | |
4105056a MD |
977 | (void) _cds_lfht_add(ht, !i ? 0 : (1UL << (i - 1)), |
978 | new_node, 0, 1); | |
979 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) | |
980 | break; | |
981 | } | |
982 | ht->cds_lfht_rcu_read_unlock(); | |
b7d619b0 MD |
983 | } |
984 | ||
985 | static | |
986 | void init_table_populate(struct cds_lfht *ht, unsigned long i, | |
987 | unsigned long len) | |
988 | { | |
989 | assert(nr_cpus_mask != -1); | |
6083a889 | 990 | if (nr_cpus_mask < 0 || len < 2 * MIN_PARTITION_PER_THREAD) { |
b7d619b0 MD |
991 | ht->cds_lfht_rcu_thread_online(); |
992 | init_table_populate_partition(ht, i, 0, len); | |
993 | ht->cds_lfht_rcu_thread_offline(); | |
994 | return; | |
995 | } | |
996 | partition_resize_helper(ht, i, len, init_table_populate_partition); | |
4105056a MD |
997 | } |
998 | ||
abc490a1 | 999 | static |
4105056a | 1000 | void init_table(struct cds_lfht *ht, |
24365af7 MD |
1001 | unsigned long first_order, unsigned long len_order) |
1002 | { | |
1003 | unsigned long i, end_order; | |
1004 | ||
f0c29ed7 | 1005 | dbg_printf("init table: first_order %lu end_order %lu\n", |
24365af7 MD |
1006 | first_order, first_order + len_order); |
1007 | end_order = first_order + len_order; | |
24365af7 | 1008 | for (i = first_order; i < end_order; i++) { |
4105056a | 1009 | unsigned long len; |
24365af7 MD |
1010 | |
1011 | len = !i ? 1 : 1UL << (i - 1); | |
f0c29ed7 | 1012 | dbg_printf("init order %lu len: %lu\n", i, len); |
4d676753 MD |
1013 | |
1014 | /* Stop expand if the resize target changes under us */ | |
1015 | if (CMM_LOAD_SHARED(ht->t.resize_target) < (!i ? 1 : (1UL << i))) | |
1016 | break; | |
1017 | ||
4105056a | 1018 | ht->t.tbl[i] = calloc(1, sizeof(struct rcu_level) |
1475579c | 1019 | + (len * sizeof(struct _cds_lfht_node))); |
b7d619b0 | 1020 | assert(ht->t.tbl[i]); |
4105056a | 1021 | |
4105056a | 1022 | /* |
dc1da8f6 MD |
1023 | * Set all dummy nodes reverse hash values for a level and |
1024 | * link all dummy nodes into the table. | |
4105056a | 1025 | */ |
dc1da8f6 | 1026 | init_table_populate(ht, i, len); |
4105056a | 1027 | |
f9c80341 MD |
1028 | /* |
1029 | * Update table size. | |
1030 | */ | |
1031 | cmm_smp_wmb(); /* populate data before RCU size */ | |
1032 | CMM_STORE_SHARED(ht->t.size, !i ? 1 : (1UL << i)); | |
1033 | ||
4105056a MD |
1034 | dbg_printf("init new size: %lu\n", !i ? 1 : (1UL << i)); |
1035 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) | |
1036 | break; | |
1037 | } | |
1038 | } | |
1039 | ||
e8de508e MD |
1040 | /* |
1041 | * Holding RCU read lock to protect _cds_lfht_remove against memory | |
1042 | * reclaim that could be performed by other call_rcu worker threads (ABA | |
1043 | * problem). | |
1044 | * For a single level, we logically remove and garbage collect each node. | |
1045 | * | |
1046 | * As a design choice, we perform logical removal and garbage collection on a | |
1047 | * node-per-node basis to simplify this algorithm. We also assume keeping good | |
1048 | * cache locality of the operation would overweight possible performance gain | |
1049 | * that could be achieved by batching garbage collection for multiple levels. | |
1050 | * However, this would have to be justified by benchmarks. | |
1051 | * | |
1052 | * Concurrent removal and add operations are helping us perform garbage | |
1053 | * collection of logically removed nodes. We guarantee that all logically | |
1054 | * removed nodes have been garbage-collected (unlinked) before call_rcu is | |
1055 | * invoked to free a hole level of dummy nodes (after a grace period). | |
1056 | * | |
1057 | * Logical removal and garbage collection can therefore be done in batch or on a | |
1058 | * node-per-node basis, as long as the guarantee above holds. | |
9ee0fc9a | 1059 | * |
b7d619b0 MD |
1060 | * When we reach a certain length, we can split this removal over many worker |
1061 | * threads, based on the number of CPUs available in the system. This should | |
1062 | * take care of not letting resize process lag behind too many concurrent | |
9ee0fc9a | 1063 | * updater threads actively inserting into the hash table. |
e8de508e | 1064 | */ |
4105056a | 1065 | static |
b7d619b0 MD |
1066 | void remove_table_partition(struct cds_lfht *ht, unsigned long i, |
1067 | unsigned long start, unsigned long len) | |
4105056a MD |
1068 | { |
1069 | unsigned long j; | |
1070 | ||
1071 | ht->cds_lfht_rcu_read_lock(); | |
b7d619b0 | 1072 | for (j = start; j < start + len; j++) { |
4105056a MD |
1073 | struct cds_lfht_node *fini_node = |
1074 | (struct cds_lfht_node *) &ht->t.tbl[i]->nodes[j]; | |
1075 | ||
1076 | dbg_printf("remove entry: i %lu j %lu hash %lu\n", | |
1077 | i, j, !i ? 0 : (1UL << (i - 1)) + j); | |
1078 | fini_node->p.reverse_hash = | |
1079 | bit_reverse_ulong(!i ? 0 : (1UL << (i - 1)) + j); | |
860d07e8 | 1080 | (void) _cds_lfht_del(ht, !i ? 0 : (1UL << (i - 1)), |
4105056a | 1081 | fini_node, 1); |
33c7c748 MD |
1082 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) |
1083 | break; | |
abc490a1 | 1084 | } |
4105056a | 1085 | ht->cds_lfht_rcu_read_unlock(); |
b7d619b0 MD |
1086 | } |
1087 | ||
1088 | static | |
1089 | void remove_table(struct cds_lfht *ht, unsigned long i, unsigned long len) | |
1090 | { | |
1091 | ||
1092 | assert(nr_cpus_mask != -1); | |
6083a889 | 1093 | if (nr_cpus_mask < 0 || len < 2 * MIN_PARTITION_PER_THREAD) { |
b7d619b0 MD |
1094 | ht->cds_lfht_rcu_thread_online(); |
1095 | remove_table_partition(ht, i, 0, len); | |
1096 | ht->cds_lfht_rcu_thread_offline(); | |
1097 | return; | |
1098 | } | |
1099 | partition_resize_helper(ht, i, len, remove_table_partition); | |
2ed95849 MD |
1100 | } |
1101 | ||
1475579c | 1102 | static |
4105056a | 1103 | void fini_table(struct cds_lfht *ht, |
1475579c MD |
1104 | unsigned long first_order, unsigned long len_order) |
1105 | { | |
1106 | long i, end_order; | |
1107 | ||
1108 | dbg_printf("fini table: first_order %lu end_order %lu\n", | |
1109 | first_order, first_order + len_order); | |
1110 | end_order = first_order + len_order; | |
1111 | assert(first_order > 0); | |
1475579c | 1112 | for (i = end_order - 1; i >= first_order; i--) { |
4105056a | 1113 | unsigned long len; |
1475579c MD |
1114 | |
1115 | len = !i ? 1 : 1UL << (i - 1); | |
1116 | dbg_printf("fini order %lu len: %lu\n", i, len); | |
4105056a | 1117 | |
4d676753 MD |
1118 | /* Stop shrink if the resize target changes under us */ |
1119 | if (CMM_LOAD_SHARED(ht->t.resize_target) > (1UL << (i - 1))) | |
1120 | break; | |
1121 | ||
1122 | cmm_smp_wmb(); /* populate data before RCU size */ | |
1123 | CMM_STORE_SHARED(ht->t.size, 1UL << (i - 1)); | |
1124 | ||
1125 | /* | |
1126 | * We need to wait for all add operations to reach Q.S. (and | |
1127 | * thus use the new table for lookups) before we can start | |
1128 | * releasing the old dummy nodes. Otherwise their lookup will | |
1129 | * return a logically removed node as insert position. | |
1130 | */ | |
1131 | ht->cds_lfht_synchronize_rcu(); | |
1132 | ||
21263e21 | 1133 | /* |
4105056a MD |
1134 | * Set "removed" flag in dummy nodes about to be removed. |
1135 | * Unlink all now-logically-removed dummy node pointers. | |
1136 | * Concurrent add/remove operation are helping us doing | |
1137 | * the gc. | |
21263e21 | 1138 | */ |
4105056a MD |
1139 | remove_table(ht, i, len); |
1140 | ||
1141 | ht->cds_lfht_call_rcu(&ht->t.tbl[i]->head, cds_lfht_free_level); | |
1142 | ||
1143 | dbg_printf("fini new size: %lu\n", 1UL << i); | |
1475579c MD |
1144 | if (CMM_LOAD_SHARED(ht->in_progress_destroy)) |
1145 | break; | |
1146 | } | |
1475579c MD |
1147 | } |
1148 | ||
7a9dcf9b | 1149 | struct cds_lfht *_cds_lfht_new(cds_lfht_hash_fct hash_fct, |
14044b37 MD |
1150 | cds_lfht_compare_fct compare_fct, |
1151 | unsigned long hash_seed, | |
1152 | unsigned long init_size, | |
b8af5011 | 1153 | int flags, |
14044b37 | 1154 | void (*cds_lfht_call_rcu)(struct rcu_head *head, |
1475579c | 1155 | void (*func)(struct rcu_head *head)), |
01dbfa62 MD |
1156 | void (*cds_lfht_synchronize_rcu)(void), |
1157 | void (*cds_lfht_rcu_read_lock)(void), | |
5f511391 MD |
1158 | void (*cds_lfht_rcu_read_unlock)(void), |
1159 | void (*cds_lfht_rcu_thread_offline)(void), | |
b7d619b0 MD |
1160 | void (*cds_lfht_rcu_thread_online)(void), |
1161 | void (*cds_lfht_rcu_register_thread)(void), | |
1162 | void (*cds_lfht_rcu_unregister_thread)(void), | |
1163 | pthread_attr_t *attr) | |
abc490a1 | 1164 | { |
14044b37 | 1165 | struct cds_lfht *ht; |
24365af7 | 1166 | unsigned long order; |
abc490a1 | 1167 | |
8129be4e | 1168 | /* init_size must be power of two */ |
49619ea0 | 1169 | if (init_size && (init_size & (init_size - 1))) |
8129be4e | 1170 | return NULL; |
14044b37 | 1171 | ht = calloc(1, sizeof(struct cds_lfht)); |
b7d619b0 | 1172 | assert(ht); |
abc490a1 | 1173 | ht->hash_fct = hash_fct; |
732ad076 MD |
1174 | ht->compare_fct = compare_fct; |
1175 | ht->hash_seed = hash_seed; | |
14044b37 | 1176 | ht->cds_lfht_call_rcu = cds_lfht_call_rcu; |
1475579c | 1177 | ht->cds_lfht_synchronize_rcu = cds_lfht_synchronize_rcu; |
01dbfa62 MD |
1178 | ht->cds_lfht_rcu_read_lock = cds_lfht_rcu_read_lock; |
1179 | ht->cds_lfht_rcu_read_unlock = cds_lfht_rcu_read_unlock; | |
5f511391 MD |
1180 | ht->cds_lfht_rcu_thread_offline = cds_lfht_rcu_thread_offline; |
1181 | ht->cds_lfht_rcu_thread_online = cds_lfht_rcu_thread_online; | |
b7d619b0 MD |
1182 | ht->cds_lfht_rcu_register_thread = cds_lfht_rcu_register_thread; |
1183 | ht->cds_lfht_rcu_unregister_thread = cds_lfht_rcu_unregister_thread; | |
1184 | ht->resize_attr = attr; | |
df44348d | 1185 | ht->percpu_count = alloc_per_cpu_items_count(); |
abc490a1 MD |
1186 | /* this mutex should not nest in read-side C.S. */ |
1187 | pthread_mutex_init(&ht->resize_mutex, NULL); | |
cd95516d | 1188 | order = get_count_order_ulong(max(init_size, MIN_TABLE_SIZE)) + 1; |
b8af5011 | 1189 | ht->flags = flags; |
5f511391 | 1190 | ht->cds_lfht_rcu_thread_offline(); |
f000907d | 1191 | pthread_mutex_lock(&ht->resize_mutex); |
4d676753 | 1192 | ht->t.resize_target = 1UL << (order - 1); |
4105056a | 1193 | init_table(ht, 0, order); |
f000907d | 1194 | pthread_mutex_unlock(&ht->resize_mutex); |
5f511391 | 1195 | ht->cds_lfht_rcu_thread_online(); |
abc490a1 MD |
1196 | return ht; |
1197 | } | |
1198 | ||
14044b37 | 1199 | struct cds_lfht_node *cds_lfht_lookup(struct cds_lfht *ht, void *key, size_t key_len) |
2ed95849 | 1200 | { |
bb7b2f26 | 1201 | struct cds_lfht_node *node, *next, *dummy_node; |
14044b37 | 1202 | struct _cds_lfht_node *lookup; |
4105056a | 1203 | unsigned long hash, reverse_hash, index, order, size; |
2ed95849 | 1204 | |
732ad076 | 1205 | hash = ht->hash_fct(key, key_len, ht->hash_seed); |
abc490a1 | 1206 | reverse_hash = bit_reverse_ulong(hash); |
464a1ec9 | 1207 | |
4105056a MD |
1208 | size = rcu_dereference(ht->t.size); |
1209 | index = hash & (size - 1); | |
24365af7 | 1210 | order = get_count_order_ulong(index + 1); |
4105056a | 1211 | lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1))) - 1)]; |
f0c29ed7 | 1212 | dbg_printf("lookup hash %lu index %lu order %lu aridx %lu\n", |
554c284e | 1213 | hash, index, order, index & (!order ? 0 : ((1UL << (order - 1)) - 1))); |
bb7b2f26 MD |
1214 | dummy_node = (struct cds_lfht_node *) lookup; |
1215 | /* We can always skip the dummy node initially */ | |
1216 | node = rcu_dereference(dummy_node->p.next); | |
bb7b2f26 | 1217 | node = clear_flag(node); |
2ed95849 | 1218 | for (;;) { |
bb7b2f26 MD |
1219 | if (unlikely(is_end(node))) { |
1220 | node = NULL; | |
abc490a1 | 1221 | break; |
bb7b2f26 | 1222 | } |
cc4fcb10 | 1223 | if (unlikely(node->p.reverse_hash > reverse_hash)) { |
abc490a1 MD |
1224 | node = NULL; |
1225 | break; | |
2ed95849 | 1226 | } |
1b81fe1a MD |
1227 | next = rcu_dereference(node->p.next); |
1228 | if (likely(!is_removed(next)) | |
1229 | && !is_dummy(next) | |
49c2e2d6 | 1230 | && likely(!ht->compare_fct(node->key, node->key_len, key, key_len))) { |
273399de | 1231 | break; |
2ed95849 | 1232 | } |
1b81fe1a | 1233 | node = clear_flag(next); |
2ed95849 | 1234 | } |
1b81fe1a | 1235 | assert(!node || !is_dummy(rcu_dereference(node->p.next))); |
abc490a1 MD |
1236 | return node; |
1237 | } | |
e0ba718a | 1238 | |
a481e5ff MD |
1239 | struct cds_lfht_node *cds_lfht_next(struct cds_lfht *ht, |
1240 | struct cds_lfht_node *node) | |
1241 | { | |
1242 | struct cds_lfht_node *next; | |
1243 | unsigned long reverse_hash; | |
1244 | void *key; | |
1245 | size_t key_len; | |
1246 | ||
1247 | reverse_hash = node->p.reverse_hash; | |
1248 | key = node->key; | |
1249 | key_len = node->key_len; | |
1250 | next = rcu_dereference(node->p.next); | |
1251 | node = clear_flag(next); | |
1252 | ||
1253 | for (;;) { | |
bb7b2f26 MD |
1254 | if (unlikely(is_end(node))) { |
1255 | node = NULL; | |
a481e5ff | 1256 | break; |
bb7b2f26 | 1257 | } |
a481e5ff MD |
1258 | if (unlikely(node->p.reverse_hash > reverse_hash)) { |
1259 | node = NULL; | |
1260 | break; | |
1261 | } | |
1262 | next = rcu_dereference(node->p.next); | |
1263 | if (likely(!is_removed(next)) | |
1264 | && !is_dummy(next) | |
1265 | && likely(!ht->compare_fct(node->key, node->key_len, key, key_len))) { | |
1266 | break; | |
1267 | } | |
1268 | node = clear_flag(next); | |
1269 | } | |
1270 | assert(!node || !is_dummy(rcu_dereference(node->p.next))); | |
1271 | return node; | |
1272 | } | |
1273 | ||
14044b37 | 1274 | void cds_lfht_add(struct cds_lfht *ht, struct cds_lfht_node *node) |
abc490a1 | 1275 | { |
4105056a | 1276 | unsigned long hash, size; |
ab7d5fc6 | 1277 | |
49c2e2d6 | 1278 | hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed); |
cc4fcb10 | 1279 | node->p.reverse_hash = bit_reverse_ulong((unsigned long) hash); |
2ed95849 | 1280 | |
4105056a MD |
1281 | size = rcu_dereference(ht->t.size); |
1282 | (void) _cds_lfht_add(ht, size, node, 0, 0); | |
1283 | ht_count_add(ht, size); | |
3eca1b8c MD |
1284 | } |
1285 | ||
14044b37 MD |
1286 | struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht, |
1287 | struct cds_lfht_node *node) | |
3eca1b8c | 1288 | { |
4105056a | 1289 | unsigned long hash, size; |
df44348d | 1290 | struct cds_lfht_node *ret; |
3eca1b8c | 1291 | |
49c2e2d6 | 1292 | hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed); |
cc4fcb10 | 1293 | node->p.reverse_hash = bit_reverse_ulong((unsigned long) hash); |
3eca1b8c | 1294 | |
4105056a MD |
1295 | size = rcu_dereference(ht->t.size); |
1296 | ret = _cds_lfht_add(ht, size, node, 1, 0); | |
17f31d1b | 1297 | if (ret == node) |
4105056a | 1298 | ht_count_add(ht, size); |
df44348d | 1299 | return ret; |
2ed95849 MD |
1300 | } |
1301 | ||
860d07e8 | 1302 | int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_node *node) |
2ed95849 | 1303 | { |
4105056a | 1304 | unsigned long size; |
df44348d | 1305 | int ret; |
abc490a1 | 1306 | |
4105056a | 1307 | size = rcu_dereference(ht->t.size); |
860d07e8 | 1308 | ret = _cds_lfht_del(ht, size, node, 0); |
df44348d | 1309 | if (!ret) |
860d07e8 | 1310 | ht_count_del(ht, size); |
df44348d | 1311 | return ret; |
2ed95849 | 1312 | } |
ab7d5fc6 | 1313 | |
abc490a1 | 1314 | static |
14044b37 | 1315 | int cds_lfht_delete_dummy(struct cds_lfht *ht) |
674f7a69 | 1316 | { |
14044b37 MD |
1317 | struct cds_lfht_node *node; |
1318 | struct _cds_lfht_node *lookup; | |
4105056a | 1319 | unsigned long order, i, size; |
674f7a69 | 1320 | |
abc490a1 | 1321 | /* Check that the table is empty */ |
4105056a | 1322 | lookup = &ht->t.tbl[0]->nodes[0]; |
14044b37 | 1323 | node = (struct cds_lfht_node *) lookup; |
abc490a1 | 1324 | do { |
1b81fe1a MD |
1325 | node = clear_flag(node)->p.next; |
1326 | if (!is_dummy(node)) | |
abc490a1 | 1327 | return -EPERM; |
273399de | 1328 | assert(!is_removed(node)); |
bb7b2f26 | 1329 | } while (!is_end(node)); |
4105056a MD |
1330 | /* |
1331 | * size accessed without rcu_dereference because hash table is | |
1332 | * being destroyed. | |
1333 | */ | |
1334 | size = ht->t.size; | |
abc490a1 | 1335 | /* Internal sanity check: all nodes left should be dummy */ |
4105056a | 1336 | for (order = 0; order < get_count_order_ulong(size) + 1; order++) { |
24365af7 MD |
1337 | unsigned long len; |
1338 | ||
1339 | len = !order ? 1 : 1UL << (order - 1); | |
1340 | for (i = 0; i < len; i++) { | |
f0c29ed7 | 1341 | dbg_printf("delete order %lu i %lu hash %lu\n", |
24365af7 | 1342 | order, i, |
4105056a MD |
1343 | bit_reverse_ulong(ht->t.tbl[order]->nodes[i].reverse_hash)); |
1344 | assert(is_dummy(ht->t.tbl[order]->nodes[i].next)); | |
24365af7 | 1345 | } |
4105056a | 1346 | poison_free(ht->t.tbl[order]); |
674f7a69 | 1347 | } |
abc490a1 | 1348 | return 0; |
674f7a69 MD |
1349 | } |
1350 | ||
1351 | /* | |
1352 | * Should only be called when no more concurrent readers nor writers can | |
1353 | * possibly access the table. | |
1354 | */ | |
b7d619b0 | 1355 | int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr) |
674f7a69 | 1356 | { |
5e28c532 MD |
1357 | int ret; |
1358 | ||
848d4088 | 1359 | /* Wait for in-flight resize operations to complete */ |
33c7c748 | 1360 | CMM_STORE_SHARED(ht->in_progress_destroy, 1); |
848d4088 MD |
1361 | while (uatomic_read(&ht->in_progress_resize)) |
1362 | poll(NULL, 0, 100); /* wait for 100ms */ | |
14044b37 | 1363 | ret = cds_lfht_delete_dummy(ht); |
abc490a1 MD |
1364 | if (ret) |
1365 | return ret; | |
df44348d | 1366 | free_per_cpu_items_count(ht->percpu_count); |
b7d619b0 MD |
1367 | if (attr) |
1368 | *attr = ht->resize_attr; | |
98808fb1 | 1369 | poison_free(ht); |
5e28c532 | 1370 | return ret; |
674f7a69 MD |
1371 | } |
1372 | ||
14044b37 | 1373 | void cds_lfht_count_nodes(struct cds_lfht *ht, |
273399de MD |
1374 | unsigned long *count, |
1375 | unsigned long *removed) | |
1376 | { | |
14044b37 MD |
1377 | struct cds_lfht_node *node, *next; |
1378 | struct _cds_lfht_node *lookup; | |
24365af7 | 1379 | unsigned long nr_dummy = 0; |
273399de MD |
1380 | |
1381 | *count = 0; | |
1382 | *removed = 0; | |
1383 | ||
24365af7 | 1384 | /* Count non-dummy nodes in the table */ |
4105056a | 1385 | lookup = &ht->t.tbl[0]->nodes[0]; |
14044b37 | 1386 | node = (struct cds_lfht_node *) lookup; |
273399de | 1387 | do { |
cc4fcb10 | 1388 | next = rcu_dereference(node->p.next); |
273399de | 1389 | if (is_removed(next)) { |
1b81fe1a | 1390 | assert(!is_dummy(next)); |
273399de | 1391 | (*removed)++; |
1b81fe1a | 1392 | } else if (!is_dummy(next)) |
273399de | 1393 | (*count)++; |
24365af7 MD |
1394 | else |
1395 | (nr_dummy)++; | |
273399de | 1396 | node = clear_flag(next); |
bb7b2f26 | 1397 | } while (!is_end(node)); |
f0c29ed7 | 1398 | dbg_printf("number of dummy nodes: %lu\n", nr_dummy); |
273399de MD |
1399 | } |
1400 | ||
1475579c | 1401 | /* called with resize mutex held */ |
abc490a1 | 1402 | static |
4105056a | 1403 | void _do_cds_lfht_grow(struct cds_lfht *ht, |
1475579c | 1404 | unsigned long old_size, unsigned long new_size) |
abc490a1 | 1405 | { |
1475579c | 1406 | unsigned long old_order, new_order; |
1475579c MD |
1407 | |
1408 | old_order = get_count_order_ulong(old_size) + 1; | |
1409 | new_order = get_count_order_ulong(new_size) + 1; | |
1410 | printf("resize from %lu (order %lu) to %lu (order %lu) buckets\n", | |
1411 | old_size, old_order, new_size, new_order); | |
1475579c | 1412 | assert(new_size > old_size); |
4105056a | 1413 | init_table(ht, old_order, new_order - old_order); |
abc490a1 MD |
1414 | } |
1415 | ||
1416 | /* called with resize mutex held */ | |
1417 | static | |
4105056a | 1418 | void _do_cds_lfht_shrink(struct cds_lfht *ht, |
1475579c | 1419 | unsigned long old_size, unsigned long new_size) |
464a1ec9 | 1420 | { |
1475579c | 1421 | unsigned long old_order, new_order; |
464a1ec9 | 1422 | |
cd95516d | 1423 | new_size = max(new_size, MIN_TABLE_SIZE); |
24365af7 | 1424 | old_order = get_count_order_ulong(old_size) + 1; |
24365af7 | 1425 | new_order = get_count_order_ulong(new_size) + 1; |
df44348d | 1426 | printf("resize from %lu (order %lu) to %lu (order %lu) buckets\n", |
df03fab8 | 1427 | old_size, old_order, new_size, new_order); |
1475579c | 1428 | assert(new_size < old_size); |
1475579c | 1429 | |
4105056a MD |
1430 | /* Remove and unlink all dummy nodes to remove. */ |
1431 | fini_table(ht, new_order, old_order - new_order); | |
464a1ec9 MD |
1432 | } |
1433 | ||
1475579c MD |
1434 | |
1435 | /* called with resize mutex held */ | |
1436 | static | |
1437 | void _do_cds_lfht_resize(struct cds_lfht *ht) | |
1438 | { | |
1439 | unsigned long new_size, old_size; | |
4105056a MD |
1440 | |
1441 | /* | |
1442 | * Resize table, re-do if the target size has changed under us. | |
1443 | */ | |
1444 | do { | |
1445 | ht->t.resize_initiated = 1; | |
1446 | old_size = ht->t.size; | |
1447 | new_size = CMM_LOAD_SHARED(ht->t.resize_target); | |
1448 | if (old_size < new_size) | |
1449 | _do_cds_lfht_grow(ht, old_size, new_size); | |
1450 | else if (old_size > new_size) | |
1451 | _do_cds_lfht_shrink(ht, old_size, new_size); | |
1452 | ht->t.resize_initiated = 0; | |
1453 | /* write resize_initiated before read resize_target */ | |
1454 | cmm_smp_mb(); | |
4d676753 | 1455 | } while (ht->t.size != CMM_LOAD_SHARED(ht->t.resize_target)); |
1475579c MD |
1456 | } |
1457 | ||
abc490a1 | 1458 | static |
4105056a | 1459 | unsigned long resize_target_update(struct cds_lfht *ht, unsigned long size, |
f9830efd | 1460 | int growth_order) |
464a1ec9 | 1461 | { |
4105056a MD |
1462 | return _uatomic_max(&ht->t.resize_target, |
1463 | size << growth_order); | |
464a1ec9 MD |
1464 | } |
1465 | ||
1475579c | 1466 | static |
4105056a | 1467 | void resize_target_update_count(struct cds_lfht *ht, |
b8af5011 | 1468 | unsigned long count) |
1475579c | 1469 | { |
cd95516d | 1470 | count = max(count, MIN_TABLE_SIZE); |
4105056a | 1471 | uatomic_set(&ht->t.resize_target, count); |
1475579c MD |
1472 | } |
1473 | ||
1474 | void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size) | |
464a1ec9 | 1475 | { |
4105056a MD |
1476 | resize_target_update_count(ht, new_size); |
1477 | CMM_STORE_SHARED(ht->t.resize_initiated, 1); | |
5f511391 | 1478 | ht->cds_lfht_rcu_thread_offline(); |
1475579c MD |
1479 | pthread_mutex_lock(&ht->resize_mutex); |
1480 | _do_cds_lfht_resize(ht); | |
1481 | pthread_mutex_unlock(&ht->resize_mutex); | |
5f511391 | 1482 | ht->cds_lfht_rcu_thread_online(); |
abc490a1 | 1483 | } |
464a1ec9 | 1484 | |
abc490a1 MD |
1485 | static |
1486 | void do_resize_cb(struct rcu_head *head) | |
1487 | { | |
1488 | struct rcu_resize_work *work = | |
1489 | caa_container_of(head, struct rcu_resize_work, head); | |
14044b37 | 1490 | struct cds_lfht *ht = work->ht; |
abc490a1 | 1491 | |
5f511391 | 1492 | ht->cds_lfht_rcu_thread_offline(); |
abc490a1 | 1493 | pthread_mutex_lock(&ht->resize_mutex); |
14044b37 | 1494 | _do_cds_lfht_resize(ht); |
abc490a1 | 1495 | pthread_mutex_unlock(&ht->resize_mutex); |
5f511391 | 1496 | ht->cds_lfht_rcu_thread_online(); |
98808fb1 | 1497 | poison_free(work); |
848d4088 MD |
1498 | cmm_smp_mb(); /* finish resize before decrement */ |
1499 | uatomic_dec(&ht->in_progress_resize); | |
464a1ec9 MD |
1500 | } |
1501 | ||
abc490a1 | 1502 | static |
4105056a | 1503 | void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth) |
ab7d5fc6 | 1504 | { |
abc490a1 | 1505 | struct rcu_resize_work *work; |
f9830efd | 1506 | unsigned long target_size; |
abc490a1 | 1507 | |
4105056a MD |
1508 | target_size = resize_target_update(ht, size, growth); |
1509 | /* Store resize_target before read resize_initiated */ | |
1510 | cmm_smp_mb(); | |
1511 | if (!CMM_LOAD_SHARED(ht->t.resize_initiated) && size < target_size) { | |
848d4088 MD |
1512 | uatomic_inc(&ht->in_progress_resize); |
1513 | cmm_smp_mb(); /* increment resize count before calling it */ | |
f9830efd MD |
1514 | work = malloc(sizeof(*work)); |
1515 | work->ht = ht; | |
14044b37 | 1516 | ht->cds_lfht_call_rcu(&work->head, do_resize_cb); |
4105056a | 1517 | CMM_STORE_SHARED(ht->t.resize_initiated, 1); |
f9830efd | 1518 | } |
ab7d5fc6 | 1519 | } |
3171717f | 1520 | |
f8994aee MD |
1521 | #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) |
1522 | ||
3171717f | 1523 | static |
4105056a | 1524 | void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size, |
3171717f MD |
1525 | unsigned long count) |
1526 | { | |
1527 | struct rcu_resize_work *work; | |
3171717f | 1528 | |
b8af5011 MD |
1529 | if (!(ht->flags & CDS_LFHT_AUTO_RESIZE)) |
1530 | return; | |
4105056a MD |
1531 | resize_target_update_count(ht, count); |
1532 | /* Store resize_target before read resize_initiated */ | |
1533 | cmm_smp_mb(); | |
1534 | if (!CMM_LOAD_SHARED(ht->t.resize_initiated)) { | |
3171717f MD |
1535 | uatomic_inc(&ht->in_progress_resize); |
1536 | cmm_smp_mb(); /* increment resize count before calling it */ | |
1537 | work = malloc(sizeof(*work)); | |
1538 | work->ht = ht; | |
1539 | ht->cds_lfht_call_rcu(&work->head, do_resize_cb); | |
4105056a | 1540 | CMM_STORE_SHARED(ht->t.resize_initiated, 1); |
3171717f MD |
1541 | } |
1542 | } | |
f8994aee MD |
1543 | |
1544 | #endif |