1 /* Functions to support a pool of allocatable objects.
2 Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2003
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
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
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
25 #include "alloc-pool.h"
27 /* Redefine abort to report an internal error w/o coredump, and
28 reporting the location of the error in the source file. This logic
29 is duplicated in rtl.h and tree.h because every file that needs the
30 special abort includes one or both. toplev.h gets too few files,
31 system.h gets too many. */
33 extern void fancy_abort (const char *, int, const char *)
35 #define abort() fancy_abort (__FILE__, __LINE__, __FUNCTION__)
37 #define align_four(x) (((x+3) >> 2) << 2)
38 #define align_eight(x) (((x+7) >> 3) << 3)
40 /* The internal allocation object. */
41 typedef struct allocation_object_def
43 #ifdef ENABLE_CHECKING
44 /* The ID of alloc pool which the object was allocated from. */
45 ALLOC_POOL_ID_TYPE id;
50 /* The data of the object. */
53 /* Because we want any type of data to be well aligned after the ID,
54 the following elements are here. They are never accessed so
55 the allocated object may be even smaller than this structure. */
58 HOST_WIDEST_INT align_i;
59 #ifdef HAVE_LONG_DOUBLE
65 /* Convert a pointer to allocation_object from a pointer to user data. */
66 #define ALLOCATION_OBJECT_PTR_FROM_USER_PTR(X) \
67 ((allocation_object *) (((char *) (X)) \
68 - offsetof (allocation_object, u.data)))
70 /* Convert a pointer to user data from a pointer to allocation_object. */
71 #define USER_PTR_FROM_ALLOCATION_OBJECT_PTR(X) \
72 ((void *) (((allocation_object *) (X))->u.data))
74 #ifdef ENABLE_CHECKING
76 static ALLOC_POOL_ID_TYPE last_id;
79 /* Create a pool of things of size SIZE, with NUM in each block we
83 create_alloc_pool (const char *name, size_t size, size_t num)
86 size_t pool_size, header_size;
91 /* Make size large enough to store the list header. */
92 if (size < sizeof (alloc_pool_list))
93 size = sizeof (alloc_pool_list);
95 /* Now align the size to a multiple of 4. */
96 size = align_four (size);
98 #ifdef ENABLE_CHECKING
99 /* Add the aligned size of ID. */
100 size += offsetof (allocation_object, u.data);
103 /* Um, we can't really allocate 0 elements per block. */
107 /* Find the size of the pool structure, and the name. */
108 pool_size = sizeof (struct alloc_pool_def);
110 /* and allocate that much memory. */
111 pool = (alloc_pool) xmalloc (pool_size);
113 /* Now init the various pieces of our pool structure. */
114 pool->name = xstrdup (name);
115 pool->elt_size = size;
116 pool->elts_per_block = num;
118 /* List header size should be a multiple of 8 */
119 header_size = align_eight (sizeof (struct alloc_pool_list_def));
121 pool->block_size = (size * num) + header_size;
122 pool->free_list = NULL;
123 pool->elts_allocated = 0;
125 pool->blocks_allocated = 0;
126 pool->block_list = NULL;
128 #ifdef ENABLE_CHECKING
129 /* Increase the last used ID and use it for this pool.
130 ID == 0 is used for free elements of pool so skip it. */
141 /* Free all memory allocated for the given memory pool. */
143 free_alloc_pool (alloc_pool pool)
145 alloc_pool_list block, next_block;
147 #ifdef ENABLE_CHECKING
152 /* Free each block allocated to the pool. */
153 for (block = pool->block_list; block != NULL; block = next_block)
155 next_block = block->next;
158 /* Lastly, free the pool and the name. */
163 /* Allocates one element from the pool specified. */
165 pool_alloc (alloc_pool pool)
167 alloc_pool_list header;
170 #ifdef ENABLE_CHECKING
175 /* If there are no more free elements, make some more!. */
176 if (!pool->free_list)
179 alloc_pool_list block_header;
182 block = (char *) xmalloc (pool->block_size);
183 block_header = (alloc_pool_list) block;
184 block += align_eight (sizeof (struct alloc_pool_list_def));
186 /* Throw it on the block list */
187 block_header->next = pool->block_list;
188 pool->block_list = block_header;
190 /* Now put the actual block pieces onto the free list. */
191 for (i = 0; i < pool->elts_per_block; i++, block += pool->elt_size)
193 #ifdef ENABLE_CHECKING
194 /* Mark the element to be free. */
195 ((allocation_object *) block)->id = 0;
197 header = (alloc_pool_list) USER_PTR_FROM_ALLOCATION_OBJECT_PTR (block);
198 header->next = pool->free_list;
199 pool->free_list = header;
201 /* Also update the number of elements we have free/allocated, and
202 increment the allocated block count. */
203 pool->elts_allocated += pool->elts_per_block;
204 pool->elts_free += pool->elts_per_block;
205 pool->blocks_allocated += 1;
208 /* Pull the first free element from the free list, and return it. */
209 header = pool->free_list;
210 pool->free_list = header->next;
213 #ifdef ENABLE_CHECKING
214 /* Set the ID for element. */
215 ALLOCATION_OBJECT_PTR_FROM_USER_PTR (header)->id = pool->id;
218 return ((void *) header);
221 /* Puts PTR back on POOL's free list. */
223 pool_free (alloc_pool pool, void *ptr)
225 alloc_pool_list header;
227 #ifdef ENABLE_CHECKING
231 /* Check whether the PTR was allocated from POOL. */
232 if (pool->id != ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr)->id)
235 /* Mark the element to be free. */
236 ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr)->id = 0;
238 /* Check if we free more than we allocated, which is Bad (TM). */
239 if (pool->elts_free + 1 > pool->elts_allocated)
243 header = (alloc_pool_list) ptr;
244 header->next = pool->free_list;
245 pool->free_list = header;