1 /* $NetBSD: pool.c,v 1.1.1.3 2014/12/10 03:34:43 christos Exp $ */
2
3 /*
4 * Copyright (C) 2013 Internet Systems Consortium, Inc. ("ISC")
5 *
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
11 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
12 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
13 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
14 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
15 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
16 * PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 /* Id */
20
21 /*! \file */
22
23 #include <config.h>
24
25 #include <string.h>
26
27 #include <isc/mem.h>
28 #include <isc/random.h>
29 #include <isc/pool.h>
30 #include <isc/util.h>
31
32 /***
33 *** Types.
34 ***/
35
36 struct isc_pool {
37 isc_mem_t * mctx;
38 unsigned int count;
39 isc_pooldeallocator_t free;
40 isc_poolinitializer_t init;
41 void * initarg;
42 void ** pool;
43 };
44
45 /***
46 *** Functions.
47 ***/
48
49 static isc_result_t
alloc_pool(isc_mem_t * mctx,unsigned int count,isc_pool_t ** poolp)50 alloc_pool(isc_mem_t *mctx, unsigned int count, isc_pool_t **poolp) {
51 isc_pool_t *pool;
52
53 pool = isc_mem_get(mctx, sizeof(*pool));
54 if (pool == NULL)
55 return (ISC_R_NOMEMORY);
56 pool->count = count;
57 pool->free = NULL;
58 pool->init = NULL;
59 pool->initarg = NULL;
60 pool->mctx = NULL;
61 isc_mem_attach(mctx, &pool->mctx);
62 pool->pool = isc_mem_get(mctx, count * sizeof(void *));
63 if (pool->pool == NULL) {
64 isc_mem_put(mctx, pool, sizeof(*pool));
65 return (ISC_R_NOMEMORY);
66 }
67 memset(pool->pool, 0, count * sizeof(void *));
68
69 *poolp = pool;
70 return (ISC_R_SUCCESS);
71 }
72
73 isc_result_t
isc_pool_create(isc_mem_t * mctx,unsigned int count,isc_pooldeallocator_t free,isc_poolinitializer_t init,void * initarg,isc_pool_t ** poolp)74 isc_pool_create(isc_mem_t *mctx, unsigned int count,
75 isc_pooldeallocator_t free,
76 isc_poolinitializer_t init, void *initarg,
77 isc_pool_t **poolp)
78 {
79 isc_pool_t *pool = NULL;
80 isc_result_t result;
81 unsigned int i;
82
83 INSIST(count > 0);
84
85 /* Allocate the pool structure */
86 result = alloc_pool(mctx, count, &pool);
87 if (result != ISC_R_SUCCESS)
88 return (result);
89
90 pool->free = free;
91 pool->init = init;
92 pool->initarg = initarg;
93
94 /* Populate the pool */
95 for (i = 0; i < count; i++) {
96 result = init(&pool->pool[i], initarg);
97 if (result != ISC_R_SUCCESS) {
98 isc_pool_destroy(&pool);
99 return (result);
100 }
101 }
102
103 *poolp = pool;
104 return (ISC_R_SUCCESS);
105 }
106
107 void *
isc_pool_get(isc_pool_t * pool)108 isc_pool_get(isc_pool_t *pool) {
109 isc_uint32_t i;
110 isc_random_get(&i);
111 return (pool->pool[i % pool->count]);
112 }
113
114 int
isc_pool_count(isc_pool_t * pool)115 isc_pool_count(isc_pool_t *pool) {
116 REQUIRE(pool != NULL);
117 return (pool->count);
118 }
119
120 isc_result_t
isc_pool_expand(isc_pool_t ** sourcep,unsigned int count,isc_pool_t ** targetp)121 isc_pool_expand(isc_pool_t **sourcep, unsigned int count,
122 isc_pool_t **targetp)
123 {
124 isc_result_t result;
125 isc_pool_t *pool;
126
127 REQUIRE(sourcep != NULL && *sourcep != NULL);
128 REQUIRE(targetp != NULL && *targetp == NULL);
129
130 pool = *sourcep;
131 if (count > pool->count) {
132 isc_pool_t *newpool = NULL;
133 unsigned int i;
134
135 /* Allocate a new pool structure */
136 result = alloc_pool(pool->mctx, count, &newpool);
137 if (result != ISC_R_SUCCESS)
138 return (result);
139
140 newpool->free = pool->free;
141 newpool->init = pool->init;
142 newpool->initarg = pool->initarg;
143
144 /* Copy over the objects from the old pool */
145 for (i = 0; i < pool->count; i++) {
146 newpool->pool[i] = pool->pool[i];
147 pool->pool[i] = NULL;
148 }
149
150 /* Populate the new entries */
151 for (i = pool->count; i < count; i++) {
152 result = pool->init(&newpool->pool[i], pool->initarg);
153 if (result != ISC_R_SUCCESS) {
154 isc_pool_destroy(&pool);
155 return (result);
156 }
157 }
158
159 isc_pool_destroy(&pool);
160 pool = newpool;
161 }
162
163 *sourcep = NULL;
164 *targetp = pool;
165 return (ISC_R_SUCCESS);
166 }
167
168 void
isc_pool_destroy(isc_pool_t ** poolp)169 isc_pool_destroy(isc_pool_t **poolp) {
170 unsigned int i;
171 isc_pool_t *pool = *poolp;
172 for (i = 0; i < pool->count; i++) {
173 if (pool->free != NULL && pool->pool[i] != NULL)
174 pool->free(&pool->pool[i]);
175 }
176 isc_mem_put(pool->mctx, pool->pool, pool->count * sizeof(void *));
177 isc_mem_putanddetach(&pool->mctx, pool, sizeof(*pool));
178 *poolp = NULL;
179 }
180