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7f22efe1 | 1 | /* Functions to support a pool of allocatable objects. |
76abd4c6 JZ |
2 | Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2003 |
3 | Free Software Foundation, Inc. | |
7f22efe1 DB |
4 | Contributed by Daniel Berlin <dan@cgsoftware.com> |
5 | ||
6 | This file is part of GCC. | |
7 | ||
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. | |
12 | ||
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. | |
17 | ||
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. */ | |
22 | ||
7f22efe1 DB |
23 | #include "config.h" |
24 | #include "system.h" | |
25 | #include "alloc-pool.h" | |
26 | ||
76abd4c6 JZ |
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. */ | |
32 | ||
4682ae04 | 33 | extern void fancy_abort (const char *, int, const char *) |
76abd4c6 JZ |
34 | ATTRIBUTE_NORETURN; |
35 | #define abort() fancy_abort (__FILE__, __LINE__, __FUNCTION__) | |
36 | ||
7f22efe1 DB |
37 | #define align_four(x) (((x+3) >> 2) << 2) |
38 | #define align_eight(x) (((x+7) >> 3) << 3) | |
39 | ||
76abd4c6 JZ |
40 | /* The internal allocation object. */ |
41 | typedef struct allocation_object_def | |
42 | { | |
43 | #ifdef ENABLE_CHECKING | |
44 | /* The ID of alloc pool which the object was allocated from. */ | |
45 | ALLOC_POOL_ID_TYPE id; | |
46 | #endif | |
47 | ||
48 | union | |
49 | { | |
50 | /* The data of the object. */ | |
51 | char data[1]; | |
52 | ||
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. */ | |
56 | char *align_p; | |
76abd4c6 | 57 | HOST_WIDEST_INT align_i; |
76abd4c6 | 58 | long double align_ld; |
76abd4c6 JZ |
59 | } u; |
60 | } allocation_object; | |
61 | ||
62 | /* Convert a pointer to allocation_object from a pointer to user data. */ | |
63 | #define ALLOCATION_OBJECT_PTR_FROM_USER_PTR(X) \ | |
64 | ((allocation_object *) (((char *) (X)) \ | |
65 | - offsetof (allocation_object, u.data))) | |
66 | ||
67 | /* Convert a pointer to user data from a pointer to allocation_object. */ | |
68 | #define USER_PTR_FROM_ALLOCATION_OBJECT_PTR(X) \ | |
69 | ((void *) (((allocation_object *) (X))->u.data)) | |
70 | ||
517958ba | 71 | #ifdef ENABLE_CHECKING |
76abd4c6 JZ |
72 | /* Last used ID. */ |
73 | static ALLOC_POOL_ID_TYPE last_id; | |
517958ba | 74 | #endif |
76abd4c6 | 75 | |
7f22efe1 DB |
76 | /* Create a pool of things of size SIZE, with NUM in each block we |
77 | allocate. */ | |
78 | ||
79 | alloc_pool | |
4682ae04 | 80 | create_alloc_pool (const char *name, size_t size, size_t num) |
7f22efe1 DB |
81 | { |
82 | alloc_pool pool; | |
83 | size_t pool_size, header_size; | |
84 | ||
85 | if (!name) | |
86 | abort (); | |
87 | ||
88 | /* Make size large enough to store the list header. */ | |
89 | if (size < sizeof (alloc_pool_list)) | |
90 | size = sizeof (alloc_pool_list); | |
91 | ||
92 | /* Now align the size to a multiple of 4. */ | |
93 | size = align_four (size); | |
94 | ||
76abd4c6 JZ |
95 | #ifdef ENABLE_CHECKING |
96 | /* Add the aligned size of ID. */ | |
97 | size += offsetof (allocation_object, u.data); | |
98 | #endif | |
99 | ||
7f22efe1 DB |
100 | /* Um, we can't really allocate 0 elements per block. */ |
101 | if (num == 0) | |
102 | abort (); | |
103 | ||
104 | /* Find the size of the pool structure, and the name. */ | |
105 | pool_size = sizeof (struct alloc_pool_def); | |
106 | ||
107 | /* and allocate that much memory. */ | |
703ad42b | 108 | pool = xmalloc (pool_size); |
7f22efe1 DB |
109 | |
110 | /* Now init the various pieces of our pool structure. */ | |
111 | pool->name = xstrdup (name); | |
112 | pool->elt_size = size; | |
113 | pool->elts_per_block = num; | |
114 | ||
6614fd40 | 115 | /* List header size should be a multiple of 8. */ |
7f22efe1 DB |
116 | header_size = align_eight (sizeof (struct alloc_pool_list_def)); |
117 | ||
118 | pool->block_size = (size * num) + header_size; | |
119 | pool->free_list = NULL; | |
120 | pool->elts_allocated = 0; | |
121 | pool->elts_free = 0; | |
122 | pool->blocks_allocated = 0; | |
123 | pool->block_list = NULL; | |
124 | ||
76abd4c6 JZ |
125 | #ifdef ENABLE_CHECKING |
126 | /* Increase the last used ID and use it for this pool. | |
127 | ID == 0 is used for free elements of pool so skip it. */ | |
128 | last_id++; | |
129 | if (last_id == 0) | |
130 | last_id++; | |
131 | ||
132 | pool->id = last_id; | |
133 | #endif | |
134 | ||
7f22efe1 DB |
135 | return (pool); |
136 | } | |
137 | ||
138 | /* Free all memory allocated for the given memory pool. */ | |
139 | void | |
4682ae04 | 140 | free_alloc_pool (alloc_pool pool) |
7f22efe1 DB |
141 | { |
142 | alloc_pool_list block, next_block; | |
143 | ||
76abd4c6 | 144 | #ifdef ENABLE_CHECKING |
7f22efe1 DB |
145 | if (!pool) |
146 | abort (); | |
76abd4c6 | 147 | #endif |
7f22efe1 DB |
148 | |
149 | /* Free each block allocated to the pool. */ | |
150 | for (block = pool->block_list; block != NULL; block = next_block) | |
151 | { | |
152 | next_block = block->next; | |
153 | free (block); | |
154 | } | |
155 | /* Lastly, free the pool and the name. */ | |
156 | free (pool->name); | |
157 | free (pool); | |
158 | } | |
159 | ||
160 | /* Allocates one element from the pool specified. */ | |
161 | void * | |
4682ae04 | 162 | pool_alloc (alloc_pool pool) |
7f22efe1 DB |
163 | { |
164 | alloc_pool_list header; | |
165 | char *block; | |
166 | ||
76abd4c6 | 167 | #ifdef ENABLE_CHECKING |
7f22efe1 DB |
168 | if (!pool) |
169 | abort (); | |
76abd4c6 | 170 | #endif |
7f22efe1 DB |
171 | |
172 | /* If there are no more free elements, make some more!. */ | |
173 | if (!pool->free_list) | |
174 | { | |
175 | size_t i; | |
176 | alloc_pool_list block_header; | |
177 | ||
f9da5064 | 178 | /* Make the block. */ |
703ad42b | 179 | block = xmalloc (pool->block_size); |
7f22efe1 DB |
180 | block_header = (alloc_pool_list) block; |
181 | block += align_eight (sizeof (struct alloc_pool_list_def)); | |
182 | ||
f9da5064 | 183 | /* Throw it on the block list. */ |
7f22efe1 DB |
184 | block_header->next = pool->block_list; |
185 | pool->block_list = block_header; | |
186 | ||
187 | /* Now put the actual block pieces onto the free list. */ | |
188 | for (i = 0; i < pool->elts_per_block; i++, block += pool->elt_size) | |
189 | { | |
76abd4c6 JZ |
190 | #ifdef ENABLE_CHECKING |
191 | /* Mark the element to be free. */ | |
192 | ((allocation_object *) block)->id = 0; | |
193 | #endif | |
194 | header = (alloc_pool_list) USER_PTR_FROM_ALLOCATION_OBJECT_PTR (block); | |
7f22efe1 DB |
195 | header->next = pool->free_list; |
196 | pool->free_list = header; | |
197 | } | |
198 | /* Also update the number of elements we have free/allocated, and | |
199 | increment the allocated block count. */ | |
200 | pool->elts_allocated += pool->elts_per_block; | |
201 | pool->elts_free += pool->elts_per_block; | |
202 | pool->blocks_allocated += 1; | |
203 | } | |
204 | ||
205 | /* Pull the first free element from the free list, and return it. */ | |
206 | header = pool->free_list; | |
207 | pool->free_list = header->next; | |
208 | pool->elts_free--; | |
76abd4c6 JZ |
209 | |
210 | #ifdef ENABLE_CHECKING | |
211 | /* Set the ID for element. */ | |
212 | ALLOCATION_OBJECT_PTR_FROM_USER_PTR (header)->id = pool->id; | |
213 | #endif | |
214 | ||
7f22efe1 DB |
215 | return ((void *) header); |
216 | } | |
217 | ||
218 | /* Puts PTR back on POOL's free list. */ | |
219 | void | |
4682ae04 | 220 | pool_free (alloc_pool pool, void *ptr) |
7f22efe1 DB |
221 | { |
222 | alloc_pool_list header; | |
223 | ||
76abd4c6 | 224 | #ifdef ENABLE_CHECKING |
7f22efe1 DB |
225 | if (!ptr) |
226 | abort (); | |
227 | ||
76abd4c6 JZ |
228 | /* Check whether the PTR was allocated from POOL. */ |
229 | if (pool->id != ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr)->id) | |
230 | abort (); | |
231 | ||
232 | /* Mark the element to be free. */ | |
233 | ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr)->id = 0; | |
234 | #else | |
7f22efe1 DB |
235 | /* Check if we free more than we allocated, which is Bad (TM). */ |
236 | if (pool->elts_free + 1 > pool->elts_allocated) | |
237 | abort (); | |
76abd4c6 JZ |
238 | #endif |
239 | ||
7f22efe1 DB |
240 | header = (alloc_pool_list) ptr; |
241 | header->next = pool->free_list; | |
242 | pool->free_list = header; | |
243 | pool->elts_free++; | |
244 | } |