freebsd-nq/usr.bin/doscmd/mem.c
1999-08-28 01:08:13 +00:00

326 lines
6.5 KiB
C

/*
* Copyright (c) 1992, 1993, 1996
* Berkeley Software Design, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Berkeley Software
* Design, Inc.
*
* THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* BSDI mem.c,v 2.2 1996/04/08 19:32:57 bostic Exp
*
* $FreeBSD$
*/
#include <stdio.h>
#include "doscmd.h"
#define Mark(x) (*(char *) (x))
#define Owner(x) (*(u_short *) ((char *)(x)+1))
#define Size(x) (*(u_short *) ((char *)(x)+3))
#define Next(x) ((char *)(x) + (Size(x)+1)*16)
/* exports */
char *dosmem;
/* locals */
static int dosmem_size;
static char *next_p = (char *)0;
static char *end_p = (char *)0xB0000L;
static char *
core_alloc(int *size)
{
char *ret;
if (*size) {
if (*size & 0xfff) {
*size = (*size & ~0xfff) + 0x1000;
}
} else {
*size = end_p - next_p;
}
if (next_p + *size > end_p) {
return NULL;
}
ret = next_p;
next_p += *size;
return ret;
}
void
mem_free_owner(int owner)
{
char *mp;
debug(D_MEMORY, " : freeow(%04x)\n", owner);
for (mp = dosmem; ; mp = Next(mp)) {
if (Owner(mp) == owner)
Owner(mp) = 0;
if (Mark(mp) != 'M')
break;
}
}
static void
mem_print(void)
{
char *mp;
for (mp = dosmem; ; mp = Next(mp)) {
debug(D_ALWAYS, "%05x: mark %c owner %04x size %04x\n",
mp, Mark(mp), Owner(mp), Size(mp));
if (Mark(mp) != 'M')
break;
}
}
void
mem_change_owner(int addr, int owner)
{
char *mp;
debug(D_MEMORY, "%04x: owner (%04x)\n", addr, owner);
addr <<= 4;
for (mp = dosmem; ; mp = Next(mp)) {
if ((int)(mp + 16) == addr)
goto found;
if (Mark(mp) != 'M')
break;
}
debug(D_ALWAYS, "%05x: illegal block in change owner\n", addr);
mem_print();
return;
found:
Owner(mp) = owner;
}
void
mem_init(void)
{
int base, avail_memory;
base = 0x600;
core_alloc(&base);
avail_memory = MAX_AVAIL_SEG * 16 - base;
dosmem = core_alloc(&avail_memory);
if (!dosmem || dosmem != (char *)base)
fatal("internal memory error\n");
dosmem_size = avail_memory / 16;
debug(D_MEMORY, "dosmem = 0x%x base = 0x%x avail = 0x%x (%dK)\n",
dosmem, base, dosmem_size, avail_memory / 1024);
Mark(dosmem) = 'Z';
Owner(dosmem) = 0;
Size(dosmem) = dosmem_size - 1;
}
static void
mem_unsplit(char *mp, int size)
{
char *nmp;
while (Mark(mp) == 'M' && Size(mp) < size) {
nmp = Next(mp);
if (Owner(nmp) != 0)
break;
Size(mp) += Size(nmp) + 1;
Mark(mp) = Mark(nmp);
}
}
static void
mem_split(char *mp, int size)
{
char *nmp;
int rest;
rest = Size(mp) - size;
Size(mp) = size;
nmp = Next(mp);
Mark(nmp) = Mark(mp);
Mark(mp) = 'M';
Owner(nmp) = 0;
Size(nmp) = rest - 1;
}
int
mem_alloc(int size, int owner, int *biggestp)
{
char *mp;
int biggest;
biggest = 0;
for (mp = dosmem; ; mp = Next(mp)) {
if (Owner(mp) == 0) {
if (Size(mp) < size)
mem_unsplit(mp, size);
if (Size(mp) >= size)
goto got;
if (Size(mp) > biggest)
biggest = Size(mp);
}
if (Mark(mp) != 'M')
break;
}
debug(D_MEMORY, "%04x: alloc(%04x, owner %04x) failed -> %d\n",
0, size, owner, biggest);
if (biggestp)
*biggestp = biggest;
return 0;
got:
if (Size(mp) > size)
mem_split(mp, size);
Owner(mp) = owner;
debug(D_MEMORY, "%04x: alloc(%04x, owner %04x)\n",
(int)mp/16 + 1, size, owner);
if (biggestp)
*biggestp = size;
return (int)mp/16 + 1;
}
int
mem_adjust(int addr, int size, int *availp)
{
char *mp;
int delta, nxtsiz;
debug(D_MEMORY, "%04x: adjust(%05x)\n", addr, size);
addr <<= 4;
for (mp = dosmem; ; mp = Next(mp)) {
if ((int)(mp + 16) == addr)
goto found;
if (Mark(mp) != 'M')
break;
}
debug(D_ALWAYS, "%05x: illegal block in adjust\n", addr);
mem_print();
return -2;
found:
if (Size(mp) < size)
mem_unsplit(mp, size);
if (Size(mp) >= size)
goto got;
debug(D_MEMORY, "%04x: adjust(%04x) failed -> %d\n",
(int)mp/16 + 1, size, Size(mp));
if (availp)
*availp = Size(mp);
return -1;
got:
if (Size(mp) > size)
mem_split(mp, size);
debug(D_MEMORY, "%04x: adjust(%04x)\n",
(int)mp/16 + 1, size);
if (availp)
*availp = size;
return 0;
}
#ifdef MEM_TEST
mem_check ()
{
struct mem_block *mp;
for (mp = mem_blocks.next; mp != &mem_blocks; mp = mp->next) {
if (mp->addr + mp->size != mp->next->addr)
break;
if (mp->inuse && mp->size == 0)
return (-1);
}
if (mp->next != &mem_blocks)
return (-1);
return (0);
}
char *blocks[10];
main ()
{
int i;
int n;
int newsize;
mem_init (0, 300);
for (i = 0; i < 100000; i++) {
n = random () % 10;
if (blocks[n]) {
newsize = random () % 20;
if ((newsize & 1) == 0)
newsize = 0;
if (0)
printf ("adjust %d %x %d\n",
n, blocks[n], newsize);
mem_adjust (blocks[n], newsize, NULL);
if (newsize == 0)
blocks[n] = NULL;
} else {
while ((newsize = random () % 20) == 0)
;
if (0)
printf ("alloc %d %d\n", n, newsize);
blocks[n] = mem_alloc (newsize, NULL);
}
if (mem_check () < 0) {
printf ("==== %d\n", i);
mem_print ();
}
}
mem_print ();
}
#endif /* MEM_TEST */