1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <stdlib.h>
18
19 #include "apr_buckets.h"
20 #include "apr_allocator.h"
21
22 #define ALLOC_AMT (8192 - APR_MEMNODE_T_SIZE)
23
24 typedef struct node_header_t {
25 apr_size_t size;
26 apr_bucket_alloc_t *alloc;
27 apr_memnode_t *memnode;
28 struct node_header_t *next;
29 } node_header_t;
30
31 #define SIZEOF_NODE_HEADER_T APR_ALIGN_DEFAULT(sizeof(node_header_t))
32 #define SMALL_NODE_SIZE (APR_BUCKET_ALLOC_SIZE + SIZEOF_NODE_HEADER_T)
33
34 /** A list of free memory from which new buckets or private bucket
35 * structures can be allocated.
36 */
37 struct apr_bucket_alloc_t {
38 apr_pool_t *pool;
39 apr_allocator_t *allocator;
40 node_header_t *freelist;
41 apr_memnode_t *blocks;
42 };
43
alloc_cleanup(void * data)44 static apr_status_t alloc_cleanup(void *data)
45 {
46 apr_bucket_alloc_t *list = data;
47
48 apr_allocator_free(list->allocator, list->blocks);
49
50 #if APR_POOL_DEBUG
51 if (list->pool && list->allocator != apr_pool_allocator_get(list->pool)) {
52 apr_allocator_destroy(list->allocator);
53 }
54 #endif
55
56 return APR_SUCCESS;
57 }
58
apr_bucket_alloc_create(apr_pool_t * p)59 APU_DECLARE_NONSTD(apr_bucket_alloc_t *) apr_bucket_alloc_create(apr_pool_t *p)
60 {
61 apr_allocator_t *allocator = apr_pool_allocator_get(p);
62 apr_bucket_alloc_t *list;
63
64 #if APR_POOL_DEBUG
65 /* may be NULL for debug mode. */
66 if (allocator == NULL) {
67 if (apr_allocator_create(&allocator) != APR_SUCCESS) {
68 apr_abortfunc_t fn = apr_pool_abort_get(p);
69 if (fn)
70 (fn)(APR_ENOMEM);
71 abort();
72 }
73 }
74 #endif
75 list = apr_bucket_alloc_create_ex(allocator);
76 if (list == NULL) {
77 apr_abortfunc_t fn = apr_pool_abort_get(p);
78 if (fn)
79 (fn)(APR_ENOMEM);
80 abort();
81 }
82 list->pool = p;
83 apr_pool_cleanup_register(list->pool, list, alloc_cleanup,
84 apr_pool_cleanup_null);
85
86 return list;
87 }
88
apr_bucket_alloc_create_ex(apr_allocator_t * allocator)89 APU_DECLARE_NONSTD(apr_bucket_alloc_t *) apr_bucket_alloc_create_ex(
90 apr_allocator_t *allocator)
91 {
92 apr_bucket_alloc_t *list;
93 apr_memnode_t *block;
94
95 block = apr_allocator_alloc(allocator, ALLOC_AMT);
96 if (!block) {
97 return NULL;
98 }
99 list = (apr_bucket_alloc_t *)block->first_avail;
100 list->pool = NULL;
101 list->allocator = allocator;
102 list->freelist = NULL;
103 list->blocks = block;
104 block->first_avail += APR_ALIGN_DEFAULT(sizeof(*list));
105
106 return list;
107 }
108
apr_bucket_alloc_destroy(apr_bucket_alloc_t * list)109 APU_DECLARE_NONSTD(void) apr_bucket_alloc_destroy(apr_bucket_alloc_t *list)
110 {
111 if (list->pool) {
112 apr_pool_cleanup_kill(list->pool, list, alloc_cleanup);
113 }
114
115 apr_allocator_free(list->allocator, list->blocks);
116
117 #if APR_POOL_DEBUG
118 if (list->pool && list->allocator != apr_pool_allocator_get(list->pool)) {
119 apr_allocator_destroy(list->allocator);
120 }
121 #endif
122 }
123
apr_bucket_alloc(apr_size_t size,apr_bucket_alloc_t * list)124 APU_DECLARE_NONSTD(void *) apr_bucket_alloc(apr_size_t size,
125 apr_bucket_alloc_t *list)
126 {
127 node_header_t *node;
128 apr_memnode_t *active = list->blocks;
129 char *endp;
130
131 size += SIZEOF_NODE_HEADER_T;
132 if (size <= SMALL_NODE_SIZE) {
133 if (list->freelist) {
134 node = list->freelist;
135 list->freelist = node->next;
136 }
137 else {
138 endp = active->first_avail + SMALL_NODE_SIZE;
139 if (endp >= active->endp) {
140 list->blocks = apr_allocator_alloc(list->allocator, ALLOC_AMT);
141 if (!list->blocks) {
142 list->blocks = active;
143 return NULL;
144 }
145 list->blocks->next = active;
146 active = list->blocks;
147 endp = active->first_avail + SMALL_NODE_SIZE;
148 }
149 node = (node_header_t *)active->first_avail;
150 node->alloc = list;
151 node->memnode = active;
152 node->size = SMALL_NODE_SIZE;
153 active->first_avail = endp;
154 }
155 }
156 else {
157 apr_memnode_t *memnode = apr_allocator_alloc(list->allocator, size);
158 if (!memnode) {
159 return NULL;
160 }
161 node = (node_header_t *)memnode->first_avail;
162 node->alloc = list;
163 node->memnode = memnode;
164 node->size = size;
165 }
166 return ((char *)node) + SIZEOF_NODE_HEADER_T;
167 }
168
169 #ifdef APR_BUCKET_DEBUG
170 #if APR_HAVE_STDLIB_H
171 #include <stdlib.h>
172 #endif
check_not_already_free(node_header_t * node)173 static void check_not_already_free(node_header_t *node)
174 {
175 apr_bucket_alloc_t *list = node->alloc;
176 node_header_t *curr = list->freelist;
177
178 while (curr) {
179 if (node == curr) {
180 abort();
181 }
182 curr = curr->next;
183 }
184 }
185 #else
186 #define check_not_already_free(node)
187 #endif
188
apr_bucket_free(void * mem)189 APU_DECLARE_NONSTD(void) apr_bucket_free(void *mem)
190 {
191 node_header_t *node = (node_header_t *)((char *)mem - SIZEOF_NODE_HEADER_T);
192 apr_bucket_alloc_t *list = node->alloc;
193
194 if (node->size == SMALL_NODE_SIZE) {
195 check_not_already_free(node);
196 node->next = list->freelist;
197 list->freelist = node;
198 }
199 else {
200 apr_allocator_free(list->allocator, node->memnode);
201 }
202 }
203