/* Copyright (C) 2000 MySQL AB   This program 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 2 of the License, or   (at your option) any later version.   This program 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 this program; if not, write to the Free Software   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA *//*    Data structures for mysys/my_alloc.c (root memory allocator)*/#ifndef _my_alloc_h#define _my_alloc_h#define ALLOC_MAX_BLOCK_TO_DROP			4096#define ALLOC_MAX_BLOCK_USAGE_BEFORE_DROP	10typedef struct st_used_mem{				   /* struct for once_alloc (block) */  struct st_used_mem *next;	   /* Next block in use */  unsigned int	left;		   /* memory left in block  */  unsigned int	size;		   /* size of block */} USED_MEM;typedef struct st_mem_root{  USED_MEM *free;                  /* blocks with free memory in it */  USED_MEM *used;                  /* blocks almost without free memory */  USED_MEM *pre_alloc;             /* preallocated block */  /* if block have less memory it will be put in 'used' list */  unsigned int min_malloc;  unsigned int block_size;         /* initial block size */  unsigned int block_num;          /* allocated blocks counter */  /*      first free block in queue test counter (if it exceed      MAX_BLOCK_USAGE_BEFORE_DROP block will be dropped in 'used' list)  */  unsigned int first_block_usage;  void (*error_handler)(void);} MEM_ROOT;#endif