Daily bump.
[official-gcc.git] / gcc / alloc-pool.c
blob14876536cdd1241dd8cfaac136edcaae8ad577ea
1 /* Functions to support a pool of allocatable objects.
2 Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2003, 2004
3 Free Software Foundation, Inc.
4 Contributed by Daniel Berlin <dan@cgsoftware.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
21 02111-1307, USA. */
23 #include "config.h"
24 #include "system.h"
25 #include "alloc-pool.h"
26 #include "hashtab.h"
28 #define align_eight(x) (((x+7) >> 3) << 3)
30 /* The internal allocation object. */
31 typedef struct allocation_object_def
33 #ifdef ENABLE_CHECKING
34 /* The ID of alloc pool which the object was allocated from. */
35 ALLOC_POOL_ID_TYPE id;
36 #endif
38 union
40 /* The data of the object. */
41 char data[1];
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;
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)))
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))
61 #ifdef ENABLE_CHECKING
62 /* Last used ID. */
63 static ALLOC_POOL_ID_TYPE last_id;
64 #endif
66 #ifdef GATHER_STATISTICS
68 /* Store information about each particular alloc_pool. */
69 struct alloc_pool_descriptor
71 const char *name;
72 int allocated;
73 int created;
74 int peak;
75 int current;
78 /* Hashtable mapping alloc_pool names to descriptors. */
79 static htab_t alloc_pool_hash;
81 /* Hashtable helpers. */
82 static hashval_t
83 hash_descriptor (const void *p)
85 const struct alloc_pool_descriptor *d = p;
86 return htab_hash_pointer (d->name);
88 static int
89 eq_descriptor (const void *p1, const void *p2)
91 const struct alloc_pool_descriptor *d = p1;
92 return d->name == p2;
95 /* For given name, return descriptor, create new if needed. */
96 static struct alloc_pool_descriptor *
97 alloc_pool_descriptor (const char *name)
99 struct alloc_pool_descriptor **slot;
101 if (!alloc_pool_hash)
102 alloc_pool_hash = htab_create (10, hash_descriptor, eq_descriptor, NULL);
104 slot = (struct alloc_pool_descriptor **)
105 htab_find_slot_with_hash (alloc_pool_hash, name,
106 htab_hash_pointer (name),
108 if (*slot)
109 return *slot;
110 *slot = xcalloc (sizeof (**slot), 1);
111 (*slot)->name = name;
112 return *slot;
114 #endif
116 /* Create a pool of things of size SIZE, with NUM in each block we
117 allocate. */
119 alloc_pool
120 create_alloc_pool (const char *name, size_t size, size_t num)
122 alloc_pool pool;
123 size_t pool_size, header_size;
124 #ifdef GATHER_STATISTICS
125 struct alloc_pool_descriptor *desc;
126 #endif
128 gcc_assert (name);
130 /* Make size large enough to store the list header. */
131 if (size < sizeof (alloc_pool_list))
132 size = sizeof (alloc_pool_list);
134 /* Now align the size to a multiple of 4. */
135 size = align_eight (size);
137 #ifdef ENABLE_CHECKING
138 /* Add the aligned size of ID. */
139 size += offsetof (allocation_object, u.data);
140 #endif
142 /* Um, we can't really allocate 0 elements per block. */
143 gcc_assert (num);
145 /* Find the size of the pool structure, and the name. */
146 pool_size = sizeof (struct alloc_pool_def);
148 /* and allocate that much memory. */
149 pool = xmalloc (pool_size);
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;
160 /* List header size should be a multiple of 8. */
161 header_size = align_eight (sizeof (struct alloc_pool_list_def));
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;
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++;
177 pool->id = last_id;
178 #endif
180 return (pool);
183 /* Free all memory allocated for the given memory pool. */
184 void
185 free_alloc_pool (alloc_pool pool)
187 alloc_pool_list block, next_block;
188 #ifdef GATHER_STATISTICS
189 struct alloc_pool_descriptor *desc = alloc_pool_descriptor (pool->name);
190 #endif
192 gcc_assert (pool);
194 /* Free each block allocated to the pool. */
195 for (block = pool->block_list; block != NULL; block = next_block)
197 next_block = block->next;
198 free (block);
199 #ifdef GATHER_STATISTICS
200 desc->current -= pool->block_size;
201 #endif
203 #ifdef ENABLE_CHECKING
204 memset (pool, 0xaf, sizeof (*pool));
205 #endif
206 /* Lastly, free the pool. */
207 free (pool);
210 /* Allocates one element from the pool specified. */
211 void *
212 pool_alloc (alloc_pool pool)
214 alloc_pool_list header;
215 char *block;
216 #ifdef GATHER_STATISTICS
217 struct alloc_pool_descriptor *desc = alloc_pool_descriptor (pool->name);
219 desc->allocated+=pool->elt_size;
220 #endif
222 gcc_assert (pool);
224 /* If there are no more free elements, make some more!. */
225 if (!pool->free_list)
227 size_t i;
228 alloc_pool_list block_header;
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
240 /* Throw it on the block list. */
241 block_header->next = pool->block_list;
242 pool->block_list = block_header;
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)
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;
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;
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--;
267 #ifdef ENABLE_CHECKING
268 /* Set the ID for element. */
269 ALLOCATION_OBJECT_PTR_FROM_USER_PTR (header)->id = pool->id;
270 #endif
272 return ((void *) header);
275 /* Puts PTR back on POOL's free list. */
276 void
277 pool_free (alloc_pool pool, void *ptr)
279 alloc_pool_list header;
281 gcc_assert (ptr);
283 #ifdef ENABLE_CHECKING
284 memset (ptr, 0xaf, pool->elt_size - offsetof (allocation_object, u.data));
286 /* Check whether the PTR was allocated from POOL. */
287 gcc_assert (pool->id == ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr)->id);
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
296 header = (alloc_pool_list) ptr;
297 header->next = pool->free_list;
298 pool->free_list = header;
299 pool->elts_free++;
301 /* Output per-alloc_pool statistics. */
302 #ifdef GATHER_STATISTICS
304 /* Used to accumulate statistics about alloc_pool sizes. */
305 struct output_info
307 int count;
308 int size;
311 /* Called via htab_traverse. Output alloc_pool descriptor pointed out by SLOT
312 and update statistics. */
313 static int
314 print_statistics (void **slot, void *b)
316 struct alloc_pool_descriptor *d = (struct alloc_pool_descriptor *) *slot;
317 struct output_info *i = (struct output_info *) b;
319 if (d->allocated)
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;
326 return 1;
328 #endif
330 /* Output per-alloc_pool memory usage statistics. */
331 void dump_alloc_pool_statistics (void)
333 #ifdef GATHER_STATISTICS
334 struct output_info info;
336 fprintf (stderr, "\nAlloc-pool Kind Pools Allocated Peak Leak\n");
337 fprintf (stderr, "-------------------------------------------------------------\n");
338 info.count = 0;
339 info.size = 0;
340 htab_traverse (alloc_pool_hash, print_statistics, &info);
341 fprintf (stderr, "-------------------------------------------------------------\n");
342 fprintf (stderr, "%-20s %7d %10d\n",
343 "Total", info.count, info.size);
344 fprintf (stderr, "-------------------------------------------------------------\n");
345 #endif