1/* Functions to support a pool of allocatable objects. 2 Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005 3 Free Software Foundation, Inc. 4 Contributed by Daniel Berlin <dan@cgsoftware.com> 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 2, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING. If not, write to the Free 20Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2102110-1301, USA. */ 22 23#include "config.h" 24#include "system.h" 25#include "alloc-pool.h" 26#include "hashtab.h" 27 28#define align_eight(x) (((x+7) >> 3) << 3) 29 30/* The internal allocation object. */ 31typedef struct allocation_object_def 32{ 33#ifdef ENABLE_CHECKING 34 /* The ID of alloc pool which the object was allocated from. */ 35 ALLOC_POOL_ID_TYPE id; 36#endif 37 38 union 39 { 40 /* The data of the object. */ 41 char data[1]; 42 43 /* Because we want any type of data to be well aligned after the ID, 44 the following elements are here. They are never accessed so 45 the allocated object may be even smaller than this structure. */ 46 char *align_p; 47 HOST_WIDEST_INT align_i; 48 long double align_ld; 49 } u; 50} allocation_object; 51 52/* Convert a pointer to allocation_object from a pointer to user data. */ 53#define ALLOCATION_OBJECT_PTR_FROM_USER_PTR(X) \ 54 ((allocation_object *) (((char *) (X)) \ 55 - offsetof (allocation_object, u.data))) 56 57/* Convert a pointer to user data from a pointer to allocation_object. */ 58#define USER_PTR_FROM_ALLOCATION_OBJECT_PTR(X) \ 59 ((void *) (((allocation_object *) (X))->u.data)) 60 61#ifdef ENABLE_CHECKING 62/* Last used ID. */ 63static ALLOC_POOL_ID_TYPE last_id; 64#endif 65 66#ifdef GATHER_STATISTICS 67 68/* Store information about each particular alloc_pool. */ 69struct alloc_pool_descriptor 70{ 71 const char *name; 72 int allocated; 73 int created; 74 int peak; 75 int current; 76}; 77 78/* Hashtable mapping alloc_pool names to descriptors. */ 79static htab_t alloc_pool_hash; 80 81/* Hashtable helpers. */ 82static hashval_t 83hash_descriptor (const void *p) 84{ 85 const struct alloc_pool_descriptor *d = p; 86 return htab_hash_pointer (d->name); 87} 88static int 89eq_descriptor (const void *p1, const void *p2) 90{ 91 const struct alloc_pool_descriptor *d = p1; 92 return d->name == p2; 93} 94 95/* For given name, return descriptor, create new if needed. */ 96static struct alloc_pool_descriptor * 97alloc_pool_descriptor (const char *name) 98{ 99 struct alloc_pool_descriptor **slot; 100 101 if (!alloc_pool_hash) 102 alloc_pool_hash = htab_create (10, hash_descriptor, eq_descriptor, NULL); 103 104 slot = (struct alloc_pool_descriptor **) 105 htab_find_slot_with_hash (alloc_pool_hash, name, 106 htab_hash_pointer (name), 107 1); 108 if (*slot) 109 return *slot; 110 *slot = xcalloc (sizeof (**slot), 1); 111 (*slot)->name = name; 112 return *slot; 113} 114#endif 115 116/* Create a pool of things of size SIZE, with NUM in each block we 117 allocate. */ 118 119alloc_pool 120create_alloc_pool (const char *name, size_t size, size_t num) 121{ 122 alloc_pool pool; 123 size_t pool_size, header_size; 124#ifdef GATHER_STATISTICS 125 struct alloc_pool_descriptor *desc; 126#endif 127 128 gcc_assert (name); 129 130 /* Make size large enough to store the list header. */ 131 if (size < sizeof (alloc_pool_list)) 132 size = sizeof (alloc_pool_list); 133 134 /* Now align the size to a multiple of 4. */ 135 size = align_eight (size); 136 137#ifdef ENABLE_CHECKING 138 /* Add the aligned size of ID. */ 139 size += offsetof (allocation_object, u.data); 140#endif 141 142 /* Um, we can't really allocate 0 elements per block. */ 143 gcc_assert (num); 144 145 /* Find the size of the pool structure, and the name. */ 146 pool_size = sizeof (struct alloc_pool_def); 147 148 /* and allocate that much memory. */ 149 pool = xmalloc (pool_size); 150 151 /* Now init the various pieces of our pool structure. */ 152 pool->name = /*xstrdup (name)*/name; 153#ifdef GATHER_STATISTICS 154 desc = alloc_pool_descriptor (name); 155 desc->created++; 156#endif 157 pool->elt_size = size; 158 pool->elts_per_block = num; 159 160 /* List header size should be a multiple of 8. */ 161 header_size = align_eight (sizeof (struct alloc_pool_list_def)); 162 163 pool->block_size = (size * num) + header_size; 164 pool->free_list = NULL; 165 pool->elts_allocated = 0; 166 pool->elts_free = 0; 167 pool->blocks_allocated = 0; 168 pool->block_list = NULL; 169 170#ifdef ENABLE_CHECKING 171 /* Increase the last used ID and use it for this pool. 172 ID == 0 is used for free elements of pool so skip it. */ 173 last_id++; 174 if (last_id == 0) 175 last_id++; 176 177 pool->id = last_id; 178#endif 179 180 return (pool); 181} 182 183/* Free all memory allocated for the given memory pool. */ 184void 185free_alloc_pool (alloc_pool pool) 186{ 187 alloc_pool_list block, next_block; 188#ifdef GATHER_STATISTICS 189 struct alloc_pool_descriptor *desc = alloc_pool_descriptor (pool->name); 190#endif 191 192 gcc_assert (pool); 193 194 /* Free each block allocated to the pool. */ 195 for (block = pool->block_list; block != NULL; block = next_block) 196 { 197 next_block = block->next; 198 free (block); 199#ifdef GATHER_STATISTICS 200 desc->current -= pool->block_size; 201#endif 202 } 203#ifdef ENABLE_CHECKING 204 memset (pool, 0xaf, sizeof (*pool)); 205#endif 206 /* Lastly, free the pool. */ 207 free (pool); 208} 209 210/* Allocates one element from the pool specified. */ 211void * 212pool_alloc (alloc_pool pool) 213{ 214 alloc_pool_list header; 215 char *block; 216#ifdef GATHER_STATISTICS 217 struct alloc_pool_descriptor *desc = alloc_pool_descriptor (pool->name); 218 219 desc->allocated+=pool->elt_size; 220#endif 221 222 gcc_assert (pool); 223 224 /* If there are no more free elements, make some more!. */ 225 if (!pool->free_list) 226 { 227 size_t i; 228 alloc_pool_list block_header; 229 230 /* Make the block. */ 231 block = xmalloc (pool->block_size); 232 block_header = (alloc_pool_list) block; 233 block += align_eight (sizeof (struct alloc_pool_list_def)); 234#ifdef GATHER_STATISTICS 235 desc->current += pool->block_size; 236 if (desc->peak < desc->current) 237 desc->peak = desc->current; 238#endif 239 240 /* Throw it on the block list. */ 241 block_header->next = pool->block_list; 242 pool->block_list = block_header; 243 244 /* Now put the actual block pieces onto the free list. */ 245 for (i = 0; i < pool->elts_per_block; i++, block += pool->elt_size) 246 { 247#ifdef ENABLE_CHECKING 248 /* Mark the element to be free. */ 249 ((allocation_object *) block)->id = 0; 250#endif 251 header = (alloc_pool_list) USER_PTR_FROM_ALLOCATION_OBJECT_PTR (block); 252 header->next = pool->free_list; 253 pool->free_list = header; 254 } 255 /* Also update the number of elements we have free/allocated, and 256 increment the allocated block count. */ 257 pool->elts_allocated += pool->elts_per_block; 258 pool->elts_free += pool->elts_per_block; 259 pool->blocks_allocated += 1; 260 } 261 262 /* Pull the first free element from the free list, and return it. */ 263 header = pool->free_list; 264 pool->free_list = header->next; 265 pool->elts_free--; 266 267#ifdef ENABLE_CHECKING 268 /* Set the ID for element. */ 269 ALLOCATION_OBJECT_PTR_FROM_USER_PTR (header)->id = pool->id; 270#endif 271 272 return ((void *) header); 273} 274 275/* Puts PTR back on POOL's free list. */ 276void 277pool_free (alloc_pool pool, void *ptr) 278{ 279 alloc_pool_list header; 280 281 gcc_assert (ptr); 282 283#ifdef ENABLE_CHECKING 284 memset (ptr, 0xaf, pool->elt_size - offsetof (allocation_object, u.data)); 285 286 /* Check whether the PTR was allocated from POOL. */ 287 gcc_assert (pool->id == ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr)->id); 288 289 /* Mark the element to be free. */ 290 ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr)->id = 0; 291#else 292 /* Check if we free more than we allocated, which is Bad (TM). */ 293 gcc_assert (pool->elts_free < pool->elts_allocated); 294#endif 295 296 header = (alloc_pool_list) ptr; 297 header->next = pool->free_list; 298 pool->free_list = header; 299 pool->elts_free++; 300} 301/* Output per-alloc_pool statistics. */ 302#ifdef GATHER_STATISTICS 303 304/* Used to accumulate statistics about alloc_pool sizes. */ 305struct output_info 306{ 307 int count; 308 int size; 309}; 310 311/* Called via htab_traverse. Output alloc_pool descriptor pointed out by SLOT 312 and update statistics. */ 313static int 314print_statistics (void **slot, void *b) 315{ 316 struct alloc_pool_descriptor *d = (struct alloc_pool_descriptor *) *slot; 317 struct output_info *i = (struct output_info *) b; 318 319 if (d->allocated) 320 { 321 fprintf (stderr, "%-21s %6d %10d %10d %10d\n", d->name, 322 d->created, d->allocated, d->peak, d->current); 323 i->size += d->allocated; 324 i->count += d->created; 325 } 326 return 1; 327} 328#endif 329 330/* Output per-alloc_pool memory usage statistics. */ 331void dump_alloc_pool_statistics (void) 332{ 333#ifdef GATHER_STATISTICS 334 struct output_info info; 335 336 if (!alloc_pool_hash) 337 return; 338 339 fprintf (stderr, "\nAlloc-pool Kind Pools Allocated Peak Leak\n"); 340 fprintf (stderr, "-------------------------------------------------------------\n"); 341 info.count = 0; 342 info.size = 0; 343 htab_traverse (alloc_pool_hash, print_statistics, &info); 344 fprintf (stderr, "-------------------------------------------------------------\n"); 345 fprintf (stderr, "%-20s %7d %10d\n", 346 "Total", info.count, info.size); 347 fprintf (stderr, "-------------------------------------------------------------\n"); 348#endif 349} 350