1/* Functions to support a pool of allocatable objects. 2 Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006 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/* Frees the alloc_pool, if it is empty and zero *POOL in this case. */ 211void 212free_alloc_pool_if_empty (alloc_pool *pool) 213{ 214 if ((*pool)->elts_free == (*pool)->elts_allocated) 215 { 216 free_alloc_pool (*pool); 217 *pool = NULL; 218 } 219} 220 221/* Allocates one element from the pool specified. */ 222void * 223pool_alloc (alloc_pool pool) 224{ 225 alloc_pool_list header; 226 char *block; 227#ifdef GATHER_STATISTICS 228 struct alloc_pool_descriptor *desc = alloc_pool_descriptor (pool->name); 229 230 desc->allocated+=pool->elt_size; 231#endif 232 233 gcc_assert (pool); 234 235 /* If there are no more free elements, make some more!. */ 236 if (!pool->free_list) 237 { 238 size_t i; 239 alloc_pool_list block_header; 240 241 /* Make the block. */ 242 block = XNEWVEC (char, pool->block_size); 243 block_header = (alloc_pool_list) block; 244 block += align_eight (sizeof (struct alloc_pool_list_def)); 245#ifdef GATHER_STATISTICS 246 desc->current += pool->block_size; 247 if (desc->peak < desc->current) 248 desc->peak = desc->current; 249#endif 250 251 /* Throw it on the block list. */ 252 block_header->next = pool->block_list; 253 pool->block_list = block_header; 254 255 /* Now put the actual block pieces onto the free list. */ 256 for (i = 0; i < pool->elts_per_block; i++, block += pool->elt_size) 257 { 258#ifdef ENABLE_CHECKING 259 /* Mark the element to be free. */ 260 ((allocation_object *) block)->id = 0; 261#endif 262 header = (alloc_pool_list) USER_PTR_FROM_ALLOCATION_OBJECT_PTR (block); 263 header->next = pool->free_list; 264 pool->free_list = header; 265 } 266 /* Also update the number of elements we have free/allocated, and 267 increment the allocated block count. */ 268 pool->elts_allocated += pool->elts_per_block; 269 pool->elts_free += pool->elts_per_block; 270 pool->blocks_allocated += 1; 271 } 272 273 /* Pull the first free element from the free list, and return it. */ 274 header = pool->free_list; 275 pool->free_list = header->next; 276 pool->elts_free--; 277 278#ifdef ENABLE_CHECKING 279 /* Set the ID for element. */ 280 ALLOCATION_OBJECT_PTR_FROM_USER_PTR (header)->id = pool->id; 281#endif 282 283 return ((void *) header); 284} 285 286/* Puts PTR back on POOL's free list. */ 287void 288pool_free (alloc_pool pool, void *ptr) 289{ 290 alloc_pool_list header; 291 292 gcc_assert (ptr); 293 294#ifdef ENABLE_CHECKING 295 memset (ptr, 0xaf, pool->elt_size - offsetof (allocation_object, u.data)); 296 297 /* Check whether the PTR was allocated from POOL. */ 298 gcc_assert (pool->id == ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr)->id); 299 300 /* Mark the element to be free. */ 301 ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr)->id = 0; 302#else 303 /* Check if we free more than we allocated, which is Bad (TM). */ 304 gcc_assert (pool->elts_free < pool->elts_allocated); 305#endif 306 307 header = (alloc_pool_list) ptr; 308 header->next = pool->free_list; 309 pool->free_list = header; 310 pool->elts_free++; 311} 312/* Output per-alloc_pool statistics. */ 313#ifdef GATHER_STATISTICS 314 315/* Used to accumulate statistics about alloc_pool sizes. */ 316struct output_info 317{ 318 int count; 319 int size; 320}; 321 322/* Called via htab_traverse. Output alloc_pool descriptor pointed out by SLOT 323 and update statistics. */ 324static int 325print_statistics (void **slot, void *b) 326{ 327 struct alloc_pool_descriptor *d = (struct alloc_pool_descriptor *) *slot; 328 struct output_info *i = (struct output_info *) b; 329 330 if (d->allocated) 331 { 332 fprintf (stderr, "%-21s %6d %10d %10d %10d\n", d->name, 333 d->created, d->allocated, d->peak, d->current); 334 i->size += d->allocated; 335 i->count += d->created; 336 } 337 return 1; 338} 339#endif 340 341/* Output per-alloc_pool memory usage statistics. */ 342void 343dump_alloc_pool_statistics (void) 344{ 345#ifdef GATHER_STATISTICS 346 struct output_info info; 347 348 if (!alloc_pool_hash) 349 return; 350 351 fprintf (stderr, "\nAlloc-pool Kind Pools Allocated Peak Leak\n"); 352 fprintf (stderr, "-------------------------------------------------------------\n"); 353 info.count = 0; 354 info.size = 0; 355 htab_traverse (alloc_pool_hash, print_statistics, &info); 356 fprintf (stderr, "-------------------------------------------------------------\n"); 357 fprintf (stderr, "%-20s %7d %10d\n", 358 "Total", info.count, info.size); 359 fprintf (stderr, "-------------------------------------------------------------\n"); 360#endif 361} 362