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0b6aa001 LJ |
1 | /* |
2 | * rculfhash-mm-order.c | |
3 | * | |
4 | * Order based memory management for Lock-Free RCU Hash Table | |
5 | * | |
6 | * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
7 | * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com> | |
8 | * | |
9 | * This library is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * This library is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with this library; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
22 | */ | |
23 | ||
24 | #include <rculfhash-internal.h> | |
25 | ||
26 | static | |
27 | void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order) | |
28 | { | |
29 | if (order == 0) { | |
30 | ht->tbl_order[0] = calloc(ht->min_nr_alloc_buckets, | |
31 | sizeof(struct cds_lfht_node)); | |
32 | assert(ht->tbl_order[0]); | |
33 | } else if (order > ht->min_alloc_buckets_order) { | |
34 | ht->tbl_order[order] = calloc(1UL << (order -1), | |
35 | sizeof(struct cds_lfht_node)); | |
36 | assert(ht->tbl_order[order]); | |
37 | } | |
38 | /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */ | |
39 | } | |
40 | ||
41 | /* | |
42 | * cds_lfht_free_bucket_table() should be called with decreasing order. | |
43 | * When cds_lfht_free_bucket_table(0) is called, it means the whole | |
44 | * lfht is destroyed. | |
45 | */ | |
46 | static | |
47 | void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order) | |
48 | { | |
49 | if (order == 0) | |
50 | poison_free(ht->tbl_order[0]); | |
51 | else if (order > ht->min_alloc_buckets_order) | |
52 | poison_free(ht->tbl_order[order]); | |
53 | /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */ | |
54 | } | |
55 | ||
56 | static | |
57 | struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index) | |
58 | { | |
59 | unsigned long order; | |
60 | ||
61 | if (index < ht->min_nr_alloc_buckets) { | |
62 | dbg_printf("bucket index %lu order 0 aridx 0\n", index); | |
63 | return &ht->tbl_order[0][index]; | |
64 | } | |
65 | /* | |
5bc6b66f MD |
66 | * equivalent to cds_lfht_get_count_order_ulong(index + 1), but |
67 | * optimizes away the non-existing 0 special-case for | |
68 | * cds_lfht_get_count_order_ulong. | |
0b6aa001 | 69 | */ |
5bc6b66f | 70 | order = cds_lfht_fls_ulong(index); |
0b6aa001 LJ |
71 | dbg_printf("bucket index %lu order %lu aridx %lu\n", |
72 | index, order, index & ((1UL << (order - 1)) - 1)); | |
73 | return &ht->tbl_order[order][index & ((1UL << (order - 1)) - 1)]; | |
74 | } | |
75 | ||
76 | static | |
77 | struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets, | |
78 | unsigned long max_nr_buckets) | |
79 | { | |
1228af1c LJ |
80 | return __default_alloc_cds_lfht( |
81 | &cds_lfht_mm_order, sizeof(struct cds_lfht), | |
82 | min_nr_alloc_buckets, max_nr_buckets); | |
0b6aa001 LJ |
83 | } |
84 | ||
85 | const struct cds_lfht_mm_type cds_lfht_mm_order = { | |
86 | .alloc_cds_lfht = alloc_cds_lfht, | |
87 | .alloc_bucket_table = cds_lfht_alloc_bucket_table, | |
88 | .free_bucket_table = cds_lfht_free_bucket_table, | |
89 | .bucket_at = bucket_at, | |
90 | }; |