1/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
2
3 This program is free software; you can redistribute it and/or modify
4 it under the terms of the GNU General Public License as published by
5 the Free Software Foundation; version 2 of the License.
6
7 This program is distributed in the hope that it will be useful,
8 but WITHOUT ANY WARRANTY; without even the implied warranty of
9 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 GNU General Public License for more details.
11
12 You should have received a copy of the GNU General Public License
13 along with this program; if not, write to the Free Software
14 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
15
16/*
17 Data structures for mysys/my_alloc.c (root memory allocator)
18*/
19
20#ifndef _my_alloc_h
21#define _my_alloc_h
22
23#define ALLOC_MAX_BLOCK_TO_DROP 4096
24#define ALLOC_MAX_BLOCK_USAGE_BEFORE_DROP 10
25
26#ifdef __cplusplus
27extern "C" {
28#endif
29
30typedef struct st_used_mem
31{ /* struct for once_alloc (block) */
32 struct st_used_mem *next; /* Next block in use */
33 unsigned int left; /* memory left in block */
34 unsigned int size; /* size of block */
35} USED_MEM;
36
37
38typedef struct st_mem_root
39{
40 USED_MEM *free; /* blocks with free memory in it */
41 USED_MEM *used; /* blocks almost without free memory */
42 USED_MEM *pre_alloc; /* preallocated block */
43 /* if block have less memory it will be put in 'used' list */
44 size_t min_malloc;
45 size_t block_size; /* initial block size */
46 unsigned int block_num; /* allocated blocks counter */
47 /*
48 first free block in queue test counter (if it exceed
49 MAX_BLOCK_USAGE_BEFORE_DROP block will be dropped in 'used' list)
50 */
51 unsigned int first_block_usage;
52
53 void (*error_handler)(void);
54} MEM_ROOT;
55
56#ifdef __cplusplus
57}
58#endif
59
60#endif
61