Commit | Line | Data |
---|---|---|
10544ee8 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-or-later |
10544ee8 | 3 | * |
c0c0989a MJ |
4 | * Copyright 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
5 | * Copyright 2011 Lai Jiangshan <laijs@cn.fujitsu.com> | |
10544ee8 | 6 | * |
c0c0989a | 7 | * Internal header for Lock-Free RCU Hash Table |
10544ee8 MD |
8 | */ |
9 | ||
c0c0989a MJ |
10 | #ifndef _LTTNG_UST_RCULFHASH_INTERNAL_H |
11 | #define _LTTNG_UST_RCULFHASH_INTERNAL_H | |
12 | ||
10544ee8 MD |
13 | #include "rculfhash.h" |
14 | #include <stdio.h> | |
15 | #include <stdlib.h> | |
16 | #include <assert.h> | |
d2dd7baa | 17 | #include "helper.h" |
10544ee8 MD |
18 | |
19 | #ifdef DEBUG | |
20 | #define dbg_printf(fmt, args...) printf("[debug lttng-ust rculfhash] " fmt, ## args) | |
21 | #else | |
22 | #define dbg_printf(fmt, args...) \ | |
23 | do { \ | |
24 | /* do nothing but check printf format */ \ | |
25 | if (0) \ | |
26 | printf("[debug lttng-ust rculfhash] " fmt, ## args); \ | |
27 | } while (0) | |
28 | #endif | |
29 | ||
30 | #if (CAA_BITS_PER_LONG == 32) | |
31 | #define MAX_TABLE_ORDER 32 | |
32 | #else | |
33 | #define MAX_TABLE_ORDER 64 | |
34 | #endif | |
35 | ||
36 | #define MAX_CHUNK_TABLE (1UL << 10) | |
37 | ||
38 | #ifndef min | |
39 | #define min(a, b) ((a) < (b) ? (a) : (b)) | |
40 | #endif | |
41 | ||
42 | #ifndef max | |
43 | #define max(a, b) ((a) > (b) ? (a) : (b)) | |
44 | #endif | |
45 | ||
46 | /* | |
47 | * lttng_ust_lfht: Top-level data structure representing a lock-free hash | |
48 | * table. Defined in the implementation file to make it be an opaque | |
49 | * cookie to users. | |
50 | * | |
51 | * The fields used in fast-paths are placed near the end of the | |
52 | * structure, because we need to have a variable-sized union to contain | |
53 | * the mm plugin fields, which are used in the fast path. | |
54 | */ | |
55 | struct lttng_ust_lfht { | |
56 | /* Initial configuration items */ | |
57 | unsigned long max_nr_buckets; | |
58 | const struct lttng_ust_lfht_mm_type *mm; /* memory management plugin */ | |
59 | const struct rcu_flavor_struct *flavor; /* RCU flavor */ | |
60 | ||
61 | /* | |
62 | * We need to put the work threads offline (QSBR) when taking this | |
63 | * mutex, because we use synchronize_rcu within this mutex critical | |
64 | * section, which waits on read-side critical sections, and could | |
65 | * therefore cause grace-period deadlock if we hold off RCU G.P. | |
66 | * completion. | |
67 | */ | |
68 | pthread_mutex_t resize_mutex; /* resize mutex: add/del mutex */ | |
69 | unsigned int in_progress_destroy; | |
70 | unsigned long resize_target; | |
71 | int resize_initiated; | |
72 | ||
73 | /* | |
74 | * Variables needed for add and remove fast-paths. | |
75 | */ | |
76 | int flags; | |
77 | unsigned long min_alloc_buckets_order; | |
78 | unsigned long min_nr_alloc_buckets; | |
79 | ||
80 | /* | |
81 | * Variables needed for the lookup, add and remove fast-paths. | |
82 | */ | |
83 | unsigned long size; /* always a power of 2, shared (RCU) */ | |
84 | /* | |
85 | * bucket_at pointer is kept here to skip the extra level of | |
86 | * dereference needed to get to "mm" (this is a fast-path). | |
87 | */ | |
88 | struct lttng_ust_lfht_node *(*bucket_at)(struct lttng_ust_lfht *ht, | |
89 | unsigned long index); | |
90 | /* | |
91 | * Dynamic length "tbl_chunk" needs to be at the end of | |
92 | * lttng_ust_lfht. | |
93 | */ | |
94 | union { | |
95 | /* | |
96 | * Contains the per order-index-level bucket node table. | |
97 | * The size of each bucket node table is half the number | |
98 | * of hashes contained in this order (except for order 0). | |
99 | * The minimum allocation buckets size parameter allows | |
100 | * combining the bucket node arrays of the lowermost | |
101 | * levels to improve cache locality for small index orders. | |
102 | */ | |
103 | struct lttng_ust_lfht_node *tbl_order[MAX_TABLE_ORDER]; | |
104 | ||
105 | /* | |
106 | * Contains the bucket node chunks. The size of each | |
107 | * bucket node chunk is ->min_alloc_size (we avoid to | |
108 | * allocate chunks with different size). Chunks improve | |
109 | * cache locality for small index orders, and are more | |
110 | * friendly with environments where allocation of large | |
111 | * contiguous memory areas is challenging due to memory | |
112 | * fragmentation concerns or inability to use virtual | |
113 | * memory addressing. | |
114 | */ | |
115 | struct lttng_ust_lfht_node *tbl_chunk[0]; | |
116 | ||
117 | /* | |
118 | * Memory mapping with room for all possible buckets. | |
119 | * Their memory is allocated when needed. | |
120 | */ | |
121 | struct lttng_ust_lfht_node *tbl_mmap; | |
122 | }; | |
123 | /* | |
124 | * End of variables needed for the lookup, add and remove | |
125 | * fast-paths. | |
126 | */ | |
127 | }; | |
128 | ||
d2dd7baa | 129 | LTTNG_HIDDEN |
10544ee8 | 130 | extern unsigned int lttng_ust_lfht_fls_ulong(unsigned long x); |
d2dd7baa MJ |
131 | LTTNG_HIDDEN |
132 | extern int lttng_ust_lfht_get_count_order_u32(uint32_t x); | |
133 | LTTNG_HIDDEN | |
10544ee8 MD |
134 | extern int lttng_ust_lfht_get_count_order_ulong(unsigned long x); |
135 | ||
136 | #ifdef POISON_FREE | |
137 | #define poison_free(ptr) \ | |
138 | do { \ | |
139 | if (ptr) { \ | |
140 | memset(ptr, 0x42, sizeof(*(ptr))); \ | |
141 | free(ptr); \ | |
142 | } \ | |
143 | } while (0) | |
144 | #else | |
145 | #define poison_free(ptr) free(ptr) | |
146 | #endif | |
147 | ||
148 | static inline | |
149 | struct lttng_ust_lfht *__default_alloc_lttng_ust_lfht( | |
150 | const struct lttng_ust_lfht_mm_type *mm, | |
151 | unsigned long lttng_ust_lfht_size, | |
152 | unsigned long min_nr_alloc_buckets, | |
153 | unsigned long max_nr_buckets) | |
154 | { | |
155 | struct lttng_ust_lfht *ht; | |
156 | ||
157 | ht = calloc(1, lttng_ust_lfht_size); | |
158 | assert(ht); | |
159 | ||
160 | ht->mm = mm; | |
161 | ht->bucket_at = mm->bucket_at; | |
162 | ht->min_nr_alloc_buckets = min_nr_alloc_buckets; | |
163 | ht->min_alloc_buckets_order = | |
164 | lttng_ust_lfht_get_count_order_ulong(min_nr_alloc_buckets); | |
165 | ht->max_nr_buckets = max_nr_buckets; | |
166 | ||
167 | return ht; | |
168 | } | |
169 | ||
170 | #endif /* _LTTNG_UST_RCULFHASH_INTERNAL_H */ |