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fcb87c50 | 1 | /* Shared pool of memory blocks for pool allocators. |
aeee4812 | 2 | Copyright (C) 2015-2023 Free Software Foundation, Inc. |
fcb87c50 MM |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 3, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GCC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GCC; see the file COPYING3. If not see | |
18 | <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | ||
21 | #ifndef MEMORY_BLOCK_H | |
22 | #define MEMORY_BLOCK_H | |
23 | ||
24 | /* Shared pool which allows other memory pools to reuse each others' allocated | |
25 | memory blocks instead of calling free/malloc again. */ | |
26 | class memory_block_pool | |
27 | { | |
28 | public: | |
29 | /* Blocks have fixed size. This is necessary for sharing. */ | |
30 | static const size_t block_size = 64 * 1024; | |
9fd052e7 JH |
31 | /* Number of blocks we keep in the freelists. */ |
32 | static const size_t freelist_size = 1024 * 1024 / block_size; | |
fcb87c50 MM |
33 | |
34 | memory_block_pool (); | |
35 | ||
36 | static inline void *allocate () ATTRIBUTE_MALLOC; | |
37 | static inline void release (void *); | |
9fd052e7 JH |
38 | static void trim (int nblocks = freelist_size); |
39 | void reduce_free_list (int); | |
fcb87c50 MM |
40 | |
41 | private: | |
42 | /* memory_block_pool singleton instance, defined in memory-block.cc. */ | |
43 | static memory_block_pool instance; | |
44 | ||
45 | struct block_list | |
46 | { | |
47 | block_list *m_next; | |
48 | }; | |
49 | ||
50 | /* Free list. */ | |
51 | block_list *m_blocks; | |
52 | }; | |
53 | ||
54 | /* Allocate a single block. Reuse a previously returned block, if possible. */ | |
55 | inline void * | |
56 | memory_block_pool::allocate () | |
57 | { | |
58 | if (instance.m_blocks == NULL) | |
59 | return XNEWVEC (char, block_size); | |
60 | ||
61 | void *result = instance.m_blocks; | |
62 | instance.m_blocks = instance.m_blocks->m_next; | |
0c6126b4 | 63 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, block_size)); |
fcb87c50 MM |
64 | return result; |
65 | } | |
66 | ||
67 | /* Return UNCAST_BLOCK to the pool. */ | |
68 | inline void | |
69 | memory_block_pool::release (void *uncast_block) | |
70 | { | |
71 | block_list *block = new (uncast_block) block_list; | |
72 | block->m_next = instance.m_blocks; | |
73 | instance.m_blocks = block; | |
d6092256 ML |
74 | |
75 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS ((char *)uncast_block | |
76 | + sizeof (block_list), | |
77 | block_size | |
78 | - sizeof (block_list))); | |
fcb87c50 MM |
79 | } |
80 | ||
81 | extern void *mempool_obstack_chunk_alloc (size_t) ATTRIBUTE_MALLOC; | |
82 | extern void mempool_obstack_chunk_free (void *); | |
83 | ||
84 | #endif /* MEMORY_BLOCK_H */ |