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bec39940 DG |
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 | ||
6c1c0768 MD |
23 | #define _GNU_SOURCE |
24 | #define _LGPL_SOURCE | |
bec39940 DG |
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 | }; |