85 lines
2.4 KiB
C
85 lines
2.4 KiB
C
|
/* Shared pool of memory blocks for pool allocators.
|
||
|
|
Copyright (C) 2015-2023 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
This file is part of GCC.
|
||
|
|
|
||
|
|
GCC is free software; you can redistribute it and/or modify
|
||
|
|
it under the terms of the GNU General Public License as published by
|
||
|
|
the Free Software Foundation; either version 3, or (at your option)
|
||
|
|
any later version.
|
||
|
|
|
||
|
|
GCC is distributed in the hope that it will be useful,
|
||
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
GNU General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU General Public License
|
||
|
|
along with GCC; see the file COPYING3. If not see
|
||
|
|
<http://www.gnu.org/licenses/>. */
|
||
|
|
|
||
|
|
|
||
|
|
#ifndef MEMORY_BLOCK_H
|
||
|
|
#define MEMORY_BLOCK_H
|
||
|
|
|
||
|
|
/* Shared pool which allows other memory pools to reuse each others' allocated
|
||
|
|
memory blocks instead of calling free/malloc again. */
|
||
|
|
class memory_block_pool
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
/* Blocks have fixed size. This is necessary for sharing. */
|
||
|
|
static const size_t block_size = 64 * 1024;
|
||
|
|
/* Number of blocks we keep in the freelists. */
|
||
|
|
static const size_t freelist_size = 1024 * 1024 / block_size;
|
||
|
|
|
||
|
|
memory_block_pool ();
|
||
|
|
|
||
|
|
static inline void *allocate () ATTRIBUTE_MALLOC;
|
||
|
|
static inline void release (void *);
|
||
|
|
static void trim (int nblocks = freelist_size);
|
||
|
|
void reduce_free_list (int);
|
||
|
|
|
||
|
|
private:
|
||
|
|
/* memory_block_pool singleton instance, defined in memory-block.cc. */
|
||
|
|
static memory_block_pool instance;
|
||
|
|
|
||
|
|
struct block_list
|
||
|
|
{
|
||
|
|
block_list *m_next;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* Free list. */
|
||
|
|
block_list *m_blocks;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* Allocate a single block. Reuse a previously returned block, if possible. */
|
||
|
|
inline void *
|
||
|
|
memory_block_pool::allocate ()
|
||
|
|
{
|
||
|
|
if (instance.m_blocks == NULL)
|
||
|
|
return XNEWVEC (char, block_size);
|
||
|
|
|
||
|
|
void *result = instance.m_blocks;
|
||
|
|
instance.m_blocks = instance.m_blocks->m_next;
|
||
|
|
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, block_size));
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Return UNCAST_BLOCK to the pool. */
|
||
|
|
inline void
|
||
|
|
memory_block_pool::release (void *uncast_block)
|
||
|
|
{
|
||
|
|
block_list *block = new (uncast_block) block_list;
|
||
|
|
block->m_next = instance.m_blocks;
|
||
|
|
instance.m_blocks = block;
|
||
|
|
|
||
|
|
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS ((char *)uncast_block
|
||
|
|
+ sizeof (block_list),
|
||
|
|
block_size
|
||
|
|
- sizeof (block_list)));
|
||
|
|
}
|
||
|
|
|
||
|
|
extern void *mempool_obstack_chunk_alloc (size_t) ATTRIBUTE_MALLOC;
|
||
|
|
extern void mempool_obstack_chunk_free (void *);
|
||
|
|
|
||
|
|
#endif /* MEMORY_BLOCK_H */
|