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 #include "apr_version.h"
22
23 #define ALLOC_AMT (8192 - APR_MEMNODE_T_SIZE)
24
25 typedef struct node_header_t {
26 apr_size_t size;
27 apr_bucket_alloc_t *alloc;
28 apr_memnode_t *memnode;
29 struct node_header_t *next;
30 } node_header_t;
31
32 #define SIZEOF_NODE_HEADER_T APR_ALIGN_DEFAULT(sizeof(node_header_t))
33 #define SMALL_NODE_SIZE (APR_BUCKET_ALLOC_SIZE + SIZEOF_NODE_HEADER_T)
34
35 /** A list of free memory from which new buckets or private bucket
36 * structures can be allocated.
37 */
38 struct apr_bucket_alloc_t {
39 apr_pool_t *pool;
40 apr_allocator_t *allocator;
41 node_header_t *freelist;
42 apr_memnode_t *blocks;
43 };
44
alloc_cleanup(void * data)45 static apr_status_t alloc_cleanup(void *data)
46 {
47 apr_bucket_alloc_t *list = data;
48
49 apr_allocator_free(list->allocator, list->blocks);
50
51 #if APR_POOL_DEBUG
52 if (list->pool && list->allocator != apr_pool_allocator_get(list->pool)) {
53 apr_allocator_destroy(list->allocator);
54 }
55 #endif
56
57 return APR_SUCCESS;
58 }
59
apr_bucket_alloc_create(apr_pool_t * p)60 APU_DECLARE_NONSTD(apr_bucket_alloc_t *) apr_bucket_alloc_create(apr_pool_t *p)
61 {
62 apr_allocator_t *allocator = apr_pool_allocator_get(p);
63 apr_bucket_alloc_t *list;
64
65 #if APR_POOL_DEBUG
66 /* may be NULL for debug mode. */
67 if (allocator == NULL) {
68 if (apr_allocator_create(&allocator) != APR_SUCCESS) {
69 apr_abortfunc_t fn = apr_pool_abort_get(p);
70 if (fn)
71 (fn)(APR_ENOMEM);
72 abort();
73 }
74 }
75 #endif
76 list = apr_bucket_alloc_create_ex(allocator);
77 if (list == NULL) {
78 apr_abortfunc_t fn = apr_pool_abort_get(p);
79 if (fn)
80 (fn)(APR_ENOMEM);
81 abort();
82 }
83 list->pool = p;
84 apr_pool_cleanup_register(list->pool, list, alloc_cleanup,
85 apr_pool_cleanup_null);
86
87 return list;
88 }
89
apr_bucket_alloc_create_ex(apr_allocator_t * allocator)90 APU_DECLARE_NONSTD(apr_bucket_alloc_t *) apr_bucket_alloc_create_ex(
91 apr_allocator_t *allocator)
92 {
93 apr_bucket_alloc_t *list;
94 apr_memnode_t *block;
95
96 block = apr_allocator_alloc(allocator, ALLOC_AMT);
97 if (!block) {
98 return NULL;
99 }
100 list = (apr_bucket_alloc_t *)block->first_avail;
101 list->pool = NULL;
102 list->allocator = allocator;
103 list->freelist = NULL;
104 list->blocks = block;
105 block->first_avail += APR_ALIGN_DEFAULT(sizeof(*list));
106
107 return list;
108 }
109
apr_bucket_alloc_destroy(apr_bucket_alloc_t * list)110 APU_DECLARE_NONSTD(void) apr_bucket_alloc_destroy(apr_bucket_alloc_t *list)
111 {
112 if (list->pool) {
113 apr_pool_cleanup_kill(list->pool, list, alloc_cleanup);
114 }
115
116 apr_allocator_free(list->allocator, list->blocks);
117
118 #if APR_POOL_DEBUG
119 if (list->pool && list->allocator != apr_pool_allocator_get(list->pool)) {
120 apr_allocator_destroy(list->allocator);
121 }
122 #endif
123 }
124
apr_bucket_alloc_aligned_floor(apr_bucket_alloc_t * list,apr_size_t size)125 APU_DECLARE_NONSTD(apr_size_t) apr_bucket_alloc_aligned_floor(apr_bucket_alloc_t *list,
126 apr_size_t size)
127 {
128 if (size <= SMALL_NODE_SIZE) {
129 size = SMALL_NODE_SIZE;
130 }
131 else {
132 #if APR_VERSION_AT_LEAST(1,6,0)
133 if (size < APR_MEMNODE_T_SIZE) {
134 size = apr_allocator_align(list->allocator, 0);
135 }
136 else {
137 size = apr_allocator_align(list->allocator,
138 size - APR_MEMNODE_T_SIZE);
139 }
140 #else
141 /* Assumes the minimum (default) allocator's boundary of 4K and
142 * minimum (immutable before APR-1.6.x) allocation size of 8K,
143 * hence possibly (yet unlikely) under-estimating the floor...
144 */
145 size = APR_ALIGN(size, 4096);
146 if (size < 8192) {
147 size = 8192;
148 }
149 #endif
150 size -= APR_MEMNODE_T_SIZE;
151 }
152 size -= SIZEOF_NODE_HEADER_T;
153 return size;
154 }
155
apr_bucket_alloc(apr_size_t size,apr_bucket_alloc_t * list)156 APU_DECLARE_NONSTD(void *) apr_bucket_alloc(apr_size_t size,
157 apr_bucket_alloc_t *list)
158 {
159 node_header_t *node;
160 apr_memnode_t *active = list->blocks;
161 char *endp;
162
163 size += SIZEOF_NODE_HEADER_T;
164 if (size <= SMALL_NODE_SIZE) {
165 if (list->freelist) {
166 node = list->freelist;
167 list->freelist = node->next;
168 }
169 else {
170 endp = active->first_avail + SMALL_NODE_SIZE;
171 if (endp >= active->endp) {
172 list->blocks = apr_allocator_alloc(list->allocator, ALLOC_AMT);
173 if (!list->blocks) {
174 list->blocks = active;
175 return NULL;
176 }
177 list->blocks->next = active;
178 active = list->blocks;
179 endp = active->first_avail + SMALL_NODE_SIZE;
180 }
181 node = (node_header_t *)active->first_avail;
182 node->alloc = list;
183 node->memnode = active;
184 node->size = SMALL_NODE_SIZE;
185 active->first_avail = endp;
186 }
187 }
188 else {
189 apr_memnode_t *memnode = apr_allocator_alloc(list->allocator, size);
190 if (!memnode) {
191 return NULL;
192 }
193 node = (node_header_t *)memnode->first_avail;
194 node->alloc = list;
195 node->memnode = memnode;
196 node->size = size;
197 }
198 return ((char *)node) + SIZEOF_NODE_HEADER_T;
199 }
200
201 #ifdef APR_BUCKET_DEBUG
202 #if APR_HAVE_STDLIB_H
203 #include <stdlib.h>
204 #endif
check_not_already_free(node_header_t * node)205 static void check_not_already_free(node_header_t *node)
206 {
207 apr_bucket_alloc_t *list = node->alloc;
208 node_header_t *curr = list->freelist;
209
210 while (curr) {
211 if (node == curr) {
212 abort();
213 }
214 curr = curr->next;
215 }
216 }
217 #else
218 #define check_not_already_free(node)
219 #endif
220
apr_bucket_free(void * mem)221 APU_DECLARE_NONSTD(void) apr_bucket_free(void *mem)
222 {
223 node_header_t *node = (node_header_t *)((char *)mem - SIZEOF_NODE_HEADER_T);
224 apr_bucket_alloc_t *list = node->alloc;
225
226 if (node->size == SMALL_NODE_SIZE) {
227 check_not_already_free(node);
228 node->next = list->freelist;
229 list->freelist = node;
230 }
231 else {
232 apr_allocator_free(list->allocator, node->memnode);
233 }
234 }
235