allocated bigger blocks if it needed (486c9c3c) · Commits · Software / OSDI20 Artifacts / mariadb

include/my_alloc.h

0 → 100644

+39 −0

Original line number	Diff line number	Diff line
		/* 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 ST_USED_MEM_DEFINED
		#define ST_USED_MEM_DEFINED
		typedef 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 */

		void (*error_handler)(void);
		} MEM_ROOT;
		#endif

include/my_sys.h

+1 −20

Original line number	Diff line number	Diff line
		@@ -464,26 +464,7 @@ typedef struct st_changeable_var {
		} CHANGEABLE_VAR;


		/* structs for alloc_root */

		#ifndef ST_USED_MEM_DEFINED
		#define ST_USED_MEM_DEFINED
		typedef struct st_used_mem { /* struct for once_alloc */
		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;
		USED_MEM *used;
		USED_MEM *pre_alloc;
		unsigned int min_malloc;
		unsigned int block_size;

		void (*error_handler)(void);
		} MEM_ROOT;
		#endif
		#include "my_alloc.h"

		/* Prototypes for mysys and my_func functions */

include/mysql.h

+1 −17

Original line number	Diff line number	Diff line
		@@ -100,23 +100,7 @@ typedef struct st_mysql_rows {

		typedef MYSQL_ROWS MYSQL_ROW_OFFSET; / offset to current row */

		#ifndef ST_USED_MEM_DEFINED
		#define ST_USED_MEM_DEFINED
		typedef struct st_used_mem { /* struct for once_alloc */
		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;
		USED_MEM *used;
		USED_MEM *pre_alloc;
		unsigned int min_malloc;
		unsigned int block_size;

		void (*error_handler)(void);
		} MEM_ROOT;
		#endif
		#include "my_alloc.h"

		typedef struct st_mysql_data {
		my_ulonglong rows;

mysys/my_alloc.c

+8 −8

Original line number	Diff line number	Diff line
		@@ -29,6 +29,7 @@ void init_alloc_root(MEM_ROOT *mem_root, uint block_size,
		mem_root->min_malloc=32;
		mem_root->block_size=block_size-MALLOC_OVERHEAD-sizeof(USED_MEM)-8;
		mem_root->error_handler=0;
		mem_root->block_num= 0;
		#if !(defined(HAVE_purify) && defined(EXTRA_DEBUG))
		if (pre_alloc_size)
		{
		@@ -61,25 +62,20 @@ gptr alloc_root(MEM_ROOT *mem_root,unsigned int Size)
		mem_root->used=next;
		return (gptr) (((char*) next)+ALIGN_SIZE(sizeof(USED_MEM)));
		#else
		uint get_size,max_left;
		uint get_size, block_size;
		gptr point;
		reg1 USED_MEM *next;
		reg2 USED_MEM **prev;

		Size= ALIGN_SIZE(Size);
		prev= &mem_root->free;
		max_left=0;
		for (next= *prev ; next && next->left < Size ; next= next->next)
		{
		if (next->left > max_left)
		max_left=next->left;
		prev= &next->next;
		}
		if (! next)
		{ /* Time to alloc new block */
		block_size= mem_root->block_size*((mem_root->block_num>>2)+1);
		get_size= Size+ALIGN_SIZE(sizeof(USED_MEM));
		if (max_left*4 < mem_root->block_size && get_size < mem_root->block_size)
		get_size=mem_root->block_size; /* Normal alloc */
		get_size= max(get_size, block_size);

		if (!(next = (USED_MEM*) my_malloc(get_size,MYF(MY_WME))))
		{
		@@ -87,6 +83,7 @@ gptr alloc_root(MEM_ROOT *mem_root,unsigned int Size)
		(*mem_root->error_handler)();
		return((gptr) 0); /* purecov: inspected */
		}
		mem_root->block_num++;
		next->next= *prev;
		next->size= get_size;
		next->left= get_size-ALIGN_SIZE(sizeof(USED_MEM));
		@@ -165,7 +162,10 @@ void free_root(MEM_ROOT *root, myf MyFlags)
		root->free=root->pre_alloc;
		root->free->left=root->pre_alloc->size-ALIGN_SIZE(sizeof(USED_MEM));
		root->free->next=0;
		root->block_num= 1;
		}
		else
		root->block_num= 0;
		DBUG_VOID_RETURN;
		}