1 /*
2 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
3 *
4 * SPDX-License-Identifier: MPL-2.0
5 *
6 * This Source Code Form is subject to the terms of the Mozilla Public
7 * License, v. 2.0. If a copy of the MPL was not distributed with this
8 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
9 *
10 * See the COPYRIGHT file distributed with this work for additional
11 * information regarding copyright ownership.
12 */
13
14 /*! \file */
15
16 #include <string.h>
17
18 #include <isc/mem.h>
19 #include <isc/pool.h>
20 #include <isc/random.h>
21 #include <isc/util.h>
22
23 /***
24 *** Types.
25 ***/
26
27 struct isc_pool {
28 isc_mem_t *mctx;
29 unsigned int count;
30 isc_pooldeallocator_t free;
31 isc_poolinitializer_t init;
32 void *initarg;
33 void **pool;
34 };
35
36 /***
37 *** Functions.
38 ***/
39
40 static isc_result_t
alloc_pool(isc_mem_t * mctx,unsigned int count,isc_pool_t ** poolp)41 alloc_pool(isc_mem_t *mctx, unsigned int count, isc_pool_t **poolp) {
42 isc_pool_t *pool;
43
44 pool = isc_mem_get(mctx, sizeof(*pool));
45 pool->count = count;
46 pool->free = NULL;
47 pool->init = NULL;
48 pool->initarg = NULL;
49 pool->mctx = NULL;
50 isc_mem_attach(mctx, &pool->mctx);
51 pool->pool = isc_mem_get(mctx, count * sizeof(void *));
52 memset(pool->pool, 0, count * sizeof(void *));
53
54 *poolp = pool;
55 return (ISC_R_SUCCESS);
56 }
57
58 isc_result_t
isc_pool_create(isc_mem_t * mctx,unsigned int count,isc_pooldeallocator_t release,isc_poolinitializer_t init,void * initarg,isc_pool_t ** poolp)59 isc_pool_create(isc_mem_t *mctx, unsigned int count,
60 isc_pooldeallocator_t release, isc_poolinitializer_t init,
61 void *initarg, isc_pool_t **poolp) {
62 isc_pool_t *pool = NULL;
63 isc_result_t result;
64 unsigned int i;
65
66 INSIST(count > 0);
67
68 /* Allocate the pool structure */
69 result = alloc_pool(mctx, count, &pool);
70 if (result != ISC_R_SUCCESS) {
71 return (result);
72 }
73
74 pool->free = release;
75 pool->init = init;
76 pool->initarg = initarg;
77
78 /* Populate the pool */
79 for (i = 0; i < count; i++) {
80 result = init(&pool->pool[i], initarg);
81 if (result != ISC_R_SUCCESS) {
82 isc_pool_destroy(&pool);
83 return (result);
84 }
85 }
86
87 *poolp = pool;
88 return (ISC_R_SUCCESS);
89 }
90
91 void *
isc_pool_get(isc_pool_t * pool)92 isc_pool_get(isc_pool_t *pool) {
93 return (pool->pool[isc_random_uniform(pool->count)]);
94 }
95
96 int
isc_pool_count(isc_pool_t * pool)97 isc_pool_count(isc_pool_t *pool) {
98 REQUIRE(pool != NULL);
99 return (pool->count);
100 }
101
102 isc_result_t
isc_pool_expand(isc_pool_t ** sourcep,unsigned int count,isc_pool_t ** targetp)103 isc_pool_expand(isc_pool_t **sourcep, unsigned int count,
104 isc_pool_t **targetp) {
105 isc_result_t result;
106 isc_pool_t *pool;
107
108 REQUIRE(sourcep != NULL && *sourcep != NULL);
109 REQUIRE(targetp != NULL && *targetp == NULL);
110
111 pool = *sourcep;
112 *sourcep = NULL;
113 if (count > pool->count) {
114 isc_pool_t *newpool = NULL;
115 unsigned int i;
116
117 /* Allocate a new pool structure */
118 result = alloc_pool(pool->mctx, count, &newpool);
119 if (result != ISC_R_SUCCESS) {
120 return (result);
121 }
122
123 newpool->free = pool->free;
124 newpool->init = pool->init;
125 newpool->initarg = pool->initarg;
126
127 /* Populate the new entries */
128 for (i = pool->count; i < count; i++) {
129 result = newpool->init(&newpool->pool[i],
130 newpool->initarg);
131 if (result != ISC_R_SUCCESS) {
132 isc_pool_destroy(&newpool);
133 return (result);
134 }
135 }
136
137 /* Copy over the objects from the old pool */
138 for (i = 0; i < pool->count; i++) {
139 newpool->pool[i] = pool->pool[i];
140 pool->pool[i] = NULL;
141 }
142
143 isc_pool_destroy(&pool);
144 pool = newpool;
145 }
146
147 *targetp = pool;
148 return (ISC_R_SUCCESS);
149 }
150
151 void
isc_pool_destroy(isc_pool_t ** poolp)152 isc_pool_destroy(isc_pool_t **poolp) {
153 unsigned int i;
154 isc_pool_t *pool = *poolp;
155 *poolp = NULL;
156 for (i = 0; i < pool->count; i++) {
157 if (pool->free != NULL && pool->pool[i] != NULL) {
158 pool->free(&pool->pool[i]);
159 }
160 }
161 isc_mem_put(pool->mctx, pool->pool, pool->count * sizeof(void *));
162 isc_mem_putanddetach(&pool->mctx, pool, sizeof(*pool));
163 }
164