]>
Commit | Line | Data |
---|---|---|
1dc6c44d | 1 | /* Shared pool of memory blocks for pool allocators. |
fbd26352 | 2 | Copyright (C) 2015-2019 Free Software Foundation, Inc. |
1dc6c44d | 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; | |
31 | ||
32 | memory_block_pool (); | |
33 | ||
34 | static inline void *allocate () ATTRIBUTE_MALLOC; | |
35 | static inline void release (void *); | |
36 | void clear_free_list (); | |
37 | ||
38 | private: | |
39 | /* memory_block_pool singleton instance, defined in memory-block.cc. */ | |
40 | static memory_block_pool instance; | |
41 | ||
42 | struct block_list | |
43 | { | |
44 | block_list *m_next; | |
45 | }; | |
46 | ||
47 | /* Free list. */ | |
48 | block_list *m_blocks; | |
49 | }; | |
50 | ||
51 | /* Allocate a single block. Reuse a previously returned block, if possible. */ | |
52 | inline void * | |
53 | memory_block_pool::allocate () | |
54 | { | |
55 | if (instance.m_blocks == NULL) | |
56 | return XNEWVEC (char, block_size); | |
57 | ||
58 | void *result = instance.m_blocks; | |
59 | instance.m_blocks = instance.m_blocks->m_next; | |
b030c82b | 60 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, block_size)); |
1dc6c44d | 61 | return result; |
62 | } | |
63 | ||
64 | /* Return UNCAST_BLOCK to the pool. */ | |
65 | inline void | |
66 | memory_block_pool::release (void *uncast_block) | |
67 | { | |
68 | block_list *block = new (uncast_block) block_list; | |
69 | block->m_next = instance.m_blocks; | |
70 | instance.m_blocks = block; | |
b3b6c6ff | 71 | |
72 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS ((char *)uncast_block | |
73 | + sizeof (block_list), | |
74 | block_size | |
75 | - sizeof (block_list))); | |
1dc6c44d | 76 | } |
77 | ||
78 | extern void *mempool_obstack_chunk_alloc (size_t) ATTRIBUTE_MALLOC; | |
79 | extern void mempool_obstack_chunk_free (void *); | |
80 | ||
81 | #endif /* MEMORY_BLOCK_H */ |