1 | /* Shared pool of memory blocks for pool allocators. |
2 | Copyright (C) 2015-2023 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | 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 | #include "config.h" |
21 | #include "system.h" |
22 | #include "coretypes.h" |
23 | #include "memory-block.h" |
24 | #include "obstack.h" |
25 | |
26 | /* Global singleton-like instance. */ |
27 | memory_block_pool memory_block_pool::instance; |
28 | |
29 | memory_block_pool::memory_block_pool () : m_blocks (NULL) {} |
30 | |
31 | /* Reduce free list to NUM blocks and return remaining to malloc. */ |
32 | void |
33 | memory_block_pool::reduce_free_list (int num) |
34 | { |
35 | block_list **blocks = &m_blocks; |
36 | |
37 | /* First skip NUM blocks. */ |
38 | |
39 | for (;num > 0 && *blocks; num--) |
40 | blocks = &(*blocks)->m_next; |
41 | |
42 | if (!*blocks) |
43 | return; |
44 | |
45 | /* And free the remainder of them. */ |
46 | |
47 | block_list *to_free = *blocks; |
48 | *blocks = NULL; |
49 | |
50 | while (to_free) |
51 | { |
52 | block_list *next = to_free->m_next; |
53 | XDELETEVEC (to_free); |
54 | to_free = next; |
55 | } |
56 | } |
57 | |
58 | /* Allocate a chunk for obstack. Use the pool if requested chunk size matches |
59 | the size of blocks in the pool. */ |
60 | void * |
61 | mempool_obstack_chunk_alloc (size_t size) |
62 | { |
63 | if (size == memory_block_pool::block_size) |
64 | return memory_block_pool::allocate (); |
65 | else |
66 | return XNEWVEC (char, size); |
67 | } |
68 | |
69 | /* Free previously allocated obstack chunk. */ |
70 | void |
71 | mempool_obstack_chunk_free (void *chunk) |
72 | { |
73 | size_t size = (reinterpret_cast<_obstack_chunk *> (chunk)->limit |
74 | - reinterpret_cast<char *> (chunk)); |
75 | if (size == memory_block_pool::block_size) |
76 | memory_block_pool::release (uncast_block: chunk); |
77 | else |
78 | XDELETEVEC (chunk); |
79 | } |
80 | |
81 | /* Return allocated memory back to malloc (and to system). */ |
82 | void |
83 | memory_block_pool::trim (int num) |
84 | { |
85 | instance.reduce_free_list (num); |
86 | } |
87 | |