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bec39940 DG |
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 | ||
6c1c0768 MD |
24 | #define _GNU_SOURCE |
25 | #define _LGPL_SOURCE | |
bec39940 DG |
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_order[0] = calloc(ht->min_nr_alloc_buckets, | |
33 | sizeof(struct cds_lfht_node)); | |
34 | assert(ht->tbl_order[0]); | |
35 | } else if (order > ht->min_alloc_buckets_order) { | |
36 | ht->tbl_order[order] = calloc(1UL << (order -1), | |
37 | sizeof(struct cds_lfht_node)); | |
38 | assert(ht->tbl_order[order]); | |
39 | } | |
40 | /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */ | |
41 | } | |
42 | ||
43 | /* | |
44 | * cds_lfht_free_bucket_table() should be called with decreasing order. | |
45 | * When cds_lfht_free_bucket_table(0) is called, it means the whole | |
46 | * lfht is destroyed. | |
47 | */ | |
48 | static | |
49 | void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order) | |
50 | { | |
51 | if (order == 0) | |
52 | poison_free(ht->tbl_order[0]); | |
53 | else if (order > ht->min_alloc_buckets_order) | |
54 | poison_free(ht->tbl_order[order]); | |
55 | /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */ | |
56 | } | |
57 | ||
58 | static | |
59 | struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index) | |
60 | { | |
61 | unsigned long order; | |
62 | ||
63 | if (index < ht->min_nr_alloc_buckets) { | |
64 | dbg_printf("bucket index %lu order 0 aridx 0\n", index); | |
65 | return &ht->tbl_order[0][index]; | |
66 | } | |
67 | /* | |
68 | * equivalent to cds_lfht_get_count_order_ulong(index + 1), but | |
69 | * optimizes away the non-existing 0 special-case for | |
70 | * cds_lfht_get_count_order_ulong. | |
71 | */ | |
72 | order = cds_lfht_fls_ulong(index); | |
73 | dbg_printf("bucket index %lu order %lu aridx %lu\n", | |
74 | index, order, index & ((1UL << (order - 1)) - 1)); | |
75 | return &ht->tbl_order[order][index & ((1UL << (order - 1)) - 1)]; | |
76 | } | |
77 | ||
78 | static | |
79 | struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets, | |
80 | unsigned long max_nr_buckets) | |
81 | { | |
82 | return __default_alloc_cds_lfht( | |
83 | &cds_lfht_mm_order, sizeof(struct cds_lfht), | |
84 | min_nr_alloc_buckets, max_nr_buckets); | |
85 | } | |
86 | ||
87 | const struct cds_lfht_mm_type cds_lfht_mm_order = { | |
88 | .alloc_cds_lfht = alloc_cds_lfht, | |
89 | .alloc_bucket_table = cds_lfht_alloc_bucket_table, | |
90 | .free_bucket_table = cds_lfht_free_bucket_table, | |
91 | .bucket_at = bucket_at, | |
92 | }; |