1 /* 2 * regional.c -- region based memory allocator. 3 * 4 * Copyright (c) 2001-2006, NLnet Labs. All rights reserved. 5 * 6 * Copyright (c) 2007, NLnet Labs. All rights reserved. 7 * 8 * This software is open source. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 14 * Redistributions of source code must retain the above copyright notice, 15 * this list of conditions and the following disclaimer. 16 * 17 * Redistributions in binary form must reproduce the above copyright notice, 18 * this list of conditions and the following disclaimer in the documentation 19 * and/or other materials provided with the distribution. 20 * 21 * Neither the name of the NLNET LABS nor the names of its contributors may 22 * be used to endorse or promote products derived from this software without 23 * specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 29 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 31 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 32 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 33 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 34 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 35 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 /** 39 * \file 40 * Regional allocator. Allocates small portions of of larger chunks. 41 */ 42 43 #include "config.h" 44 #include "util/log.h" 45 #include "util/regional.h" 46 47 #ifdef ALIGNMENT 48 # undef ALIGNMENT 49 #endif 50 /** increase size until it fits alignment of s bytes */ 51 #define ALIGN_UP(x, s) (((x) + s - 1) & (~(s - 1))) 52 /** what size to align on; make sure a char* fits in it. */ 53 #define ALIGNMENT (sizeof(uint64_t)) 54 55 /** Default reasonable size for chunks */ 56 #define REGIONAL_CHUNK_SIZE 8192 57 #ifdef UNBOUND_ALLOC_NONREGIONAL 58 /** All objects allocated outside of chunks, for debug */ 59 #define REGIONAL_LARGE_OBJECT_SIZE 0 60 #else 61 /** Default size for large objects - allocated outside of chunks. */ 62 #define REGIONAL_LARGE_OBJECT_SIZE 2048 63 #endif 64 65 struct regional* 66 regional_create(void) 67 { 68 return regional_create_custom(REGIONAL_CHUNK_SIZE); 69 } 70 71 /** init regional struct with first block */ 72 static void 73 regional_init(struct regional* r) 74 { 75 size_t a = ALIGN_UP(sizeof(struct regional), ALIGNMENT); 76 r->data = (char*)r + a; 77 r->available = r->first_size - a; 78 r->next = NULL; 79 r->large_list = NULL; 80 r->total_large = 0; 81 } 82 83 /** 84 * Create a new region, with custom first block and large-object sizes. 85 * @param size: length of first block. 86 * @param large_object_size: outside of chunk allocation threshold. 87 * @return: newly allocated regional. 88 */ 89 static struct regional* 90 regional_create_custom_large_object(size_t size, size_t large_object_size) 91 { 92 struct regional* r; 93 size = ALIGN_UP(size, ALIGNMENT); 94 r = (struct regional*)malloc(size); 95 log_assert(sizeof(struct regional) <= size); 96 if(!r) return NULL; 97 r->first_size = size; 98 r->large_object_size = large_object_size; 99 regional_init(r); 100 return r; 101 } 102 103 struct regional* 104 regional_create_custom(size_t size) 105 { 106 return regional_create_custom_large_object(size, 107 REGIONAL_LARGE_OBJECT_SIZE); 108 } 109 110 struct regional* 111 regional_create_nochunk(size_t size) 112 { 113 return regional_create_custom_large_object(size, 0); 114 } 115 116 void 117 regional_free_all(struct regional *r) 118 { 119 char* p = r->next, *np; 120 while(p) { 121 np = *(char**)p; 122 free(p); 123 p = np; 124 } 125 p = r->large_list; 126 while(p) { 127 np = *(char**)p; 128 free(p); 129 p = np; 130 } 131 regional_init(r); 132 } 133 134 void 135 regional_destroy(struct regional *r) 136 { 137 if(!r) return; 138 regional_free_all(r); 139 free(r); 140 } 141 142 void * 143 regional_alloc(struct regional *r, size_t size) 144 { 145 size_t a; 146 void *s; 147 if( 148 #if SIZEOF_SIZE_T == 8 149 (unsigned long long)size >= 0xffffffffffffff00ULL 150 #else 151 (unsigned)size >= (unsigned)0xffffff00UL 152 #endif 153 ) 154 return NULL; /* protect against integer overflow in 155 malloc and ALIGN_UP */ 156 a = ALIGN_UP(size, ALIGNMENT); 157 /* large objects */ 158 if(a > r->large_object_size) { 159 s = malloc(ALIGNMENT + size); 160 if(!s) return NULL; 161 r->total_large += ALIGNMENT+size; 162 *(char**)s = r->large_list; 163 r->large_list = (char*)s; 164 return (char*)s+ALIGNMENT; 165 } 166 /* create a new chunk */ 167 if(a > r->available) { 168 s = malloc(REGIONAL_CHUNK_SIZE); 169 if(!s) return NULL; 170 *(char**)s = r->next; 171 r->next = (char*)s; 172 r->data = (char*)s + ALIGNMENT; 173 r->available = REGIONAL_CHUNK_SIZE - ALIGNMENT; 174 } 175 /* put in this chunk */ 176 r->available -= a; 177 s = r->data; 178 r->data += a; 179 return s; 180 } 181 182 void * 183 regional_alloc_init(struct regional* r, const void *init, size_t size) 184 { 185 void *s = regional_alloc(r, size); 186 if(!s) return NULL; 187 memcpy(s, init, size); 188 return s; 189 } 190 191 void * 192 regional_alloc_zero(struct regional *r, size_t size) 193 { 194 void *s = regional_alloc(r, size); 195 if(!s) return NULL; 196 memset(s, 0, size); 197 return s; 198 } 199 200 char * 201 regional_strdup(struct regional *r, const char *string) 202 { 203 return (char*)regional_alloc_init(r, string, strlen(string)+1); 204 } 205 206 /** 207 * reasonably slow, but stats and get_mem are not supposed to be fast 208 * count the number of chunks in use 209 */ 210 static size_t 211 count_chunks(struct regional* r) 212 { 213 size_t c = 1; 214 char* p = r->next; 215 while(p) { 216 c++; 217 p = *(char**)p; 218 } 219 return c; 220 } 221 222 /** 223 * also reasonably slow, counts the number of large objects 224 */ 225 static size_t 226 count_large(struct regional* r) 227 { 228 size_t c = 0; 229 char* p = r->large_list; 230 while(p) { 231 c++; 232 p = *(char**)p; 233 } 234 return c; 235 } 236 237 void 238 regional_log_stats(struct regional *r) 239 { 240 /* some basic assertions put here (non time critical code) */ 241 log_assert(ALIGNMENT >= sizeof(char*)); 242 log_assert(REGIONAL_CHUNK_SIZE > ALIGNMENT); 243 log_assert(REGIONAL_CHUNK_SIZE-ALIGNMENT > r->large_object_size); 244 log_assert(REGIONAL_CHUNK_SIZE >= sizeof(struct regional)); 245 /* debug print */ 246 log_info("regional %u chunks, %u large", 247 (unsigned)count_chunks(r), (unsigned)count_large(r)); 248 } 249 250 size_t 251 regional_get_mem(struct regional* r) 252 { 253 return r->first_size + (count_chunks(r)-1)*REGIONAL_CHUNK_SIZE 254 + r->total_large; 255 } 256