Fix: relayd: don't call lttng_ht_destroy in RCU read-side C.S.
[lttng-tools.git] / src / common / hashtable / rculfhash-mm-chunk.c
1 /*
2 * rculfhash-mm-chunk.c
3 *
4 * Chunk based memory management for Lock-Free RCU Hash Table
5 *
6 * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #define _GNU_SOURCE
24 #define _LGPL_SOURCE
25 #include <stddef.h>
26 #include "rculfhash-internal.h"
27
28 static
29 void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order)
30 {
31 if (order == 0) {
32 ht->tbl_chunk[0] = calloc(ht->min_nr_alloc_buckets,
33 sizeof(struct cds_lfht_node));
34 assert(ht->tbl_chunk[0]);
35 } else if (order > ht->min_alloc_buckets_order) {
36 unsigned long i, len = 1UL << (order - 1 - ht->min_alloc_buckets_order);
37
38 for (i = len; i < 2 * len; i++) {
39 ht->tbl_chunk[i] = calloc(ht->min_nr_alloc_buckets,
40 sizeof(struct cds_lfht_node));
41 assert(ht->tbl_chunk[i]);
42 }
43 }
44 /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
45 }
46
47 /*
48 * cds_lfht_free_bucket_table() should be called with decreasing order.
49 * When cds_lfht_free_bucket_table(0) is called, it means the whole
50 * lfht is destroyed.
51 */
52 static
53 void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order)
54 {
55 if (order == 0)
56 poison_free(ht->tbl_chunk[0]);
57 else if (order > ht->min_alloc_buckets_order) {
58 unsigned long i, len = 1UL << (order - 1 - ht->min_alloc_buckets_order);
59
60 for (i = len; i < 2 * len; i++)
61 poison_free(ht->tbl_chunk[i]);
62 }
63 /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
64 }
65
66 static
67 struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index)
68 {
69 unsigned long chunk, offset;
70
71 chunk = index >> ht->min_alloc_buckets_order;
72 offset = index & (ht->min_nr_alloc_buckets - 1);
73 return &ht->tbl_chunk[chunk][offset];
74 }
75
76 static
77 struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets,
78 unsigned long max_nr_buckets)
79 {
80 unsigned long nr_chunks, cds_lfht_size;
81
82 min_nr_alloc_buckets = max(min_nr_alloc_buckets,
83 max_nr_buckets / MAX_CHUNK_TABLE);
84 nr_chunks = max_nr_buckets / min_nr_alloc_buckets;
85 cds_lfht_size = offsetof(struct cds_lfht, tbl_chunk) +
86 sizeof(struct cds_lfht_node *) * nr_chunks;
87 cds_lfht_size = max(cds_lfht_size, sizeof(struct cds_lfht));
88
89 return __default_alloc_cds_lfht(
90 &cds_lfht_mm_chunk, cds_lfht_size,
91 min_nr_alloc_buckets, max_nr_buckets);
92 }
93
94 const struct cds_lfht_mm_type cds_lfht_mm_chunk = {
95 .alloc_cds_lfht = alloc_cds_lfht,
96 .alloc_bucket_table = cds_lfht_alloc_bucket_table,
97 .free_bucket_table = cds_lfht_free_bucket_table,
98 .bucket_at = bucket_at,
99 };
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