1 /* Functions to support a pool of allocatable objects.
2 Copyright (C) 1987-2015 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dan@cgsoftware.com>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
24 #include "alloc-pool.h"
25 #include "hash-table.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
;
40 /* The data of the object. */
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 We do not care about alignment for floating-point types. */
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
63 static ALLOC_POOL_ID_TYPE last_id
;
66 /* Store information about each particular alloc_pool. Note that this
67 will underestimate the amount the amount of storage used by a small amount:
68 1) The overhead in a pool is not accounted for.
69 2) The unallocated elements in a block are not accounted for. Note
70 that this can at worst case be one element smaller that the block
71 size for that pool. */
72 struct alloc_pool_descriptor
74 /* Number of pools allocated. */
75 unsigned long created
;
76 /* Gross allocated storage. */
77 unsigned long allocated
;
78 /* Amount of currently active storage. */
79 unsigned long current
;
80 /* Peak amount of storage used. */
82 /* Size of element in the pool. */
86 /* Hashtable mapping alloc_pool names to descriptors. */
87 static hash_map
<const char *, alloc_pool_descriptor
> *alloc_pool_hash
;
89 /* For given name, return descriptor, create new if needed. */
90 static struct alloc_pool_descriptor
*
91 allocate_pool_descriptor (const char *name
)
94 alloc_pool_hash
= new hash_map
<const char *, alloc_pool_descriptor
> (10,
98 return &alloc_pool_hash
->get_or_insert (name
);
101 /* Create a pool of things of size SIZE, with NUM in each block we
105 create_alloc_pool (const char *name
, size_t size
, size_t num
)
110 gcc_checking_assert (name
);
112 /* Make size large enough to store the list header. */
113 if (size
< sizeof (alloc_pool_list
))
114 size
= sizeof (alloc_pool_list
);
116 /* Now align the size to a multiple of 4. */
117 size
= align_eight (size
);
119 #ifdef ENABLE_CHECKING
120 /* Add the aligned size of ID. */
121 size
+= offsetof (allocation_object
, u
.data
);
124 /* Um, we can't really allocate 0 elements per block. */
125 gcc_checking_assert (num
);
127 /* Allocate memory for the pool structure. */
128 pool
= XNEW (struct alloc_pool_def
);
130 /* Now init the various pieces of our pool structure. */
131 pool
->name
= /*xstrdup (name)*/name
;
132 pool
->elt_size
= size
;
133 pool
->elts_per_block
= num
;
135 if (GATHER_STATISTICS
)
137 struct alloc_pool_descriptor
*desc
= allocate_pool_descriptor (name
);
138 desc
->elt_size
= size
;
142 /* List header size should be a multiple of 8. */
143 header_size
= align_eight (sizeof (struct alloc_pool_list_def
));
145 pool
->block_size
= (size
* num
) + header_size
;
146 pool
->returned_free_list
= NULL
;
147 pool
->virgin_free_list
= NULL
;
148 pool
->virgin_elts_remaining
= 0;
149 pool
->elts_allocated
= 0;
151 pool
->blocks_allocated
= 0;
152 pool
->block_list
= NULL
;
154 #ifdef ENABLE_CHECKING
155 /* Increase the last used ID and use it for this pool.
156 ID == 0 is used for free elements of pool so skip it. */
167 /* Free all memory allocated for the given memory pool. */
169 empty_alloc_pool (alloc_pool pool
)
171 alloc_pool_list block
, next_block
;
173 gcc_checking_assert (pool
);
175 /* Free each block allocated to the pool. */
176 for (block
= pool
->block_list
; block
!= NULL
; block
= next_block
)
178 next_block
= block
->next
;
182 if (GATHER_STATISTICS
)
184 struct alloc_pool_descriptor
*desc
= allocate_pool_descriptor (pool
->name
);
185 desc
->current
-= (pool
->elts_allocated
- pool
->elts_free
) * pool
->elt_size
;
188 pool
->returned_free_list
= NULL
;
189 pool
->virgin_free_list
= NULL
;
190 pool
->virgin_elts_remaining
= 0;
191 pool
->elts_allocated
= 0;
193 pool
->blocks_allocated
= 0;
194 pool
->block_list
= NULL
;
197 /* Free all memory allocated for the given memory pool and the pool itself. */
199 free_alloc_pool (alloc_pool pool
)
201 /* First empty the pool. */
202 empty_alloc_pool (pool
);
203 #ifdef ENABLE_CHECKING
204 memset (pool
, 0xaf, sizeof (*pool
));
206 /* Lastly, free the pool. */
210 /* Frees the alloc_pool, if it is empty and zero *POOL in this case. */
212 free_alloc_pool_if_empty (alloc_pool
*pool
)
214 if ((*pool
)->elts_free
== (*pool
)->elts_allocated
)
216 free_alloc_pool (*pool
);
221 /* Allocates one element from the pool specified. */
223 pool_alloc (alloc_pool pool
)
225 alloc_pool_list header
;
226 #ifdef ENABLE_VALGRIND_ANNOTATIONS
230 if (GATHER_STATISTICS
)
232 struct alloc_pool_descriptor
*desc
= allocate_pool_descriptor (pool
->name
);
234 desc
->allocated
+= pool
->elt_size
;
235 desc
->current
+= pool
->elt_size
;
236 if (desc
->peak
< desc
->current
)
237 desc
->peak
= desc
->current
;
240 gcc_checking_assert (pool
);
241 #ifdef ENABLE_VALGRIND_ANNOTATIONS
242 size
= pool
->elt_size
- offsetof (allocation_object
, u
.data
);
245 /* If there are no more free elements, make some more!. */
246 if (!pool
->returned_free_list
)
249 if (!pool
->virgin_elts_remaining
)
251 alloc_pool_list block_header
;
253 /* Make the block. */
254 block
= XNEWVEC (char, pool
->block_size
);
255 block_header
= (alloc_pool_list
) block
;
256 block
+= align_eight (sizeof (struct alloc_pool_list_def
));
258 /* Throw it on the block list. */
259 block_header
->next
= pool
->block_list
;
260 pool
->block_list
= block_header
;
262 /* Make the block available for allocation. */
263 pool
->virgin_free_list
= block
;
264 pool
->virgin_elts_remaining
= pool
->elts_per_block
;
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;
274 /* We now know that we can take the first elt off the virgin list and
275 put it on the returned list. */
276 block
= pool
->virgin_free_list
;
277 header
= (alloc_pool_list
) USER_PTR_FROM_ALLOCATION_OBJECT_PTR (block
);
279 #ifdef ENABLE_CHECKING
280 /* Mark the element to be free. */
281 ((allocation_object
*) block
)->id
= 0;
283 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (header
,size
));
284 pool
->returned_free_list
= header
;
285 pool
->virgin_free_list
+= pool
->elt_size
;
286 pool
->virgin_elts_remaining
--;
290 /* Pull the first free element from the free list, and return it. */
291 header
= pool
->returned_free_list
;
292 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (header
, sizeof (*header
)));
293 pool
->returned_free_list
= header
->next
;
296 #ifdef ENABLE_CHECKING
297 /* Set the ID for element. */
298 ALLOCATION_OBJECT_PTR_FROM_USER_PTR (header
)->id
= pool
->id
;
300 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (header
, size
));
302 return ((void *) header
);
305 /* Puts PTR back on POOL's free list. */
307 pool_free (alloc_pool pool
, void *ptr
)
309 alloc_pool_list header
;
310 #if defined(ENABLE_VALGRIND_ANNOTATIONS) || defined(ENABLE_CHECKING)
312 size
= pool
->elt_size
- offsetof (allocation_object
, u
.data
);
315 #ifdef ENABLE_CHECKING
317 /* Check if we free more than we allocated, which is Bad (TM). */
318 && pool
->elts_free
< pool
->elts_allocated
319 /* Check whether the PTR was allocated from POOL. */
320 && pool
->id
== ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr
)->id
);
322 memset (ptr
, 0xaf, size
);
324 /* Mark the element to be free. */
325 ALLOCATION_OBJECT_PTR_FROM_USER_PTR (ptr
)->id
= 0;
328 header
= (alloc_pool_list
) ptr
;
329 header
->next
= pool
->returned_free_list
;
330 pool
->returned_free_list
= header
;
331 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (ptr
, size
));
334 if (GATHER_STATISTICS
)
336 struct alloc_pool_descriptor
*desc
= allocate_pool_descriptor (pool
->name
);
337 desc
->current
-= pool
->elt_size
;
341 /* Output per-alloc_pool statistics. */
343 /* Used to accumulate statistics about alloc_pool sizes. */
344 struct pool_output_info
346 unsigned long total_created
;
347 unsigned long total_allocated
;
350 /* Called via hash_map.traverse. Output alloc_pool descriptor pointed out by
351 SLOT and update statistics. */
353 print_alloc_pool_statistics (const char *const &name
,
354 const alloc_pool_descriptor
&d
,
355 struct pool_output_info
*i
)
360 "%-22s %6d %10lu %10lu(%10lu) %10lu(%10lu) %10lu(%10lu)\n",
361 name
, d
.elt_size
, d
.created
, d
.allocated
,
362 d
.allocated
/ d
.elt_size
, d
.peak
, d
.peak
/ d
.elt_size
,
363 d
.current
, d
.current
/ d
.elt_size
);
364 i
->total_allocated
+= d
.allocated
;
365 i
->total_created
+= d
.created
;
370 /* Output per-alloc_pool memory usage statistics. */
372 dump_alloc_pool_statistics (void)
374 struct pool_output_info info
;
376 if (! GATHER_STATISTICS
)
379 if (!alloc_pool_hash
)
382 fprintf (stderr
, "\nAlloc-pool Kind Elt size Pools Allocated (elts) Peak (elts) Leak (elts)\n");
383 fprintf (stderr
, "--------------------------------------------------------------------------------------------------------------\n");
384 info
.total_created
= 0;
385 info
.total_allocated
= 0;
386 alloc_pool_hash
->traverse
<struct pool_output_info
*,
387 print_alloc_pool_statistics
> (&info
);
388 fprintf (stderr
, "--------------------------------------------------------------------------------------------------------------\n");
389 fprintf (stderr
, "%-22s %7lu %10lu\n",
390 "Total", info
.total_created
, info
.total_allocated
);
391 fprintf (stderr
, "--------------------------------------------------------------------------------------------------------------\n");