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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2001 by Sun Microsystems, Inc.
* All rights reserved.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Portions Copyright (c) 2005 Gunnar Ritter, Freiburg i. Br., Germany
*
* Sccsid @(#)blok.c 1.7 (gritter) 6/16/05
*/
/* from OpenSolaris "blok.c 1.19 05/06/08 SMI" */
/*
* UNIX shell
*/
#include "defs.h"
/*
* storage allocator
* (circular first fit strategy)
*/
#define BUSY 01
#define busy(x) (Rcheat((x)->word) & BUSY)
unsigned brkincr = BRKINCR;
struct blk *blokp; /* current search pointer */
struct blk *bloktop; /* top of arena (last blok) */
unsigned char *brkbegin;
void *
alloc(nbytes)
size_t nbytes;
{
register unsigned rbytes = round(nbytes+BYTESPERWORD, BYTESPERWORD);
if (stakbot == 0) {
addblok((unsigned)0);
}
for (;;)
{
int c = 0;
register struct blk *p = blokp;
register struct blk *q;
do
{
if (!busy(p))
{
while (!busy(q = p->word))
p->word = q->word;
if ((char *)q - (char *)p >= rbytes)
{
blokp = (struct blk *)
((char *)p + rbytes);
if (q > blokp)
blokp->word = p->word;
p->word = (struct blk *)
(Rcheat(blokp) | BUSY);
return ((char *)(p + 1));
}
}
q = p;
p = (struct blk *)(Rcheat(p->word) & ~BUSY);
} while (p > q || (c++) == 0);
addblok(rbytes);
}
}
void
addblok(unsigned reqd)
{
if (stakbot == 0)
{
brkbegin = setbrk(3 * BRKINCR);
bloktop = (struct blk *)brkbegin;
}
if (stakbas != staktop)
{
register unsigned char *rndstak;
register struct blk *blokstak;
if (staktop >= brkend)
growstak(staktop);
pushstak(0);
rndstak = (unsigned char *)round(staktop, BYTESPERWORD);
blokstak = (struct blk *)(stakbas) - 1;
blokstak->word = stakbsy;
stakbsy = blokstak;
bloktop->word = (struct blk *)(Rcheat(rndstak) | BUSY);
bloktop = (struct blk *)(rndstak);
}
reqd += brkincr;
reqd &= ~(brkincr - 1);
blokp = bloktop;
/*
* brkend points to the first invalid address.
* make sure bloktop is valid.
*/
if ((unsigned char *)&bloktop->word >= brkend)
{
if (setbrk((unsigned)((unsigned char *)
(&bloktop->word) - brkend + sizeof (struct blk))) ==
(unsigned char *)-1)
error(nospace);
}
bloktop = bloktop->word = (struct blk *)(Rcheat(bloktop) + reqd);
if ((unsigned char *)&bloktop->word >= brkend)
{
if (setbrk((unsigned)((unsigned char *)
(&bloktop->word) - brkend + sizeof (struct blk))) ==
(unsigned char *)-1)
error(nospace);
}
bloktop->word = (struct blk *)(brkbegin + 1);
{
register unsigned char *stakadr = (unsigned char *)
(bloktop + 2);
register unsigned char *sp = stakadr;
if (reqd = (staktop-stakbot))
{
if (stakadr + reqd >= brkend)
growstak(stakadr + reqd);
while (reqd-- > 0)
*sp++ = *stakbot++;
sp--;
}
staktop = sp;
if (staktop >= brkend)
growstak(staktop);
stakbas = stakbot = stakadr;
}
}
void
free(ap)
void *ap;
{
register struct blk *p;
if ((p = (struct blk *)ap) && p < bloktop && p > (struct blk *)brkbegin)
{
#ifdef DEBUG
chkbptr(p);
#endif
--p;
p->word = (struct blk *)(Rcheat(p->word) & ~BUSY);
}
}
#ifdef DEBUG
int
chkbptr(struct blk *ptr)
{
int exf = 0;
register struct blk *p = (struct blk *)brkbegin;
register struct blk *q;
int us = 0, un = 0;
for (;;)
{
q = (struct blk *)(Rcheat(p->word) & ~BUSY);
if (p+1 == ptr)
exf++;
if (q < (struct blk *)brkbegin || q > bloktop)
abort(3);
if (p == bloktop)
break;
if (busy(p))
us += q - p;
else
un += q - p;
if (p >= q)
abort(4);
p = q;
}
if (exf == 0)
abort(1);
}
int
chkmem(void)
{
register struct blk *p = (struct blk *)brkbegin;
register struct blk *q;
int us = 0, un = 0;
for (;;) {
q = (struct blk *)(Rcheat(p->word) & ~BUSY);
if (q < (struct blk *)brkbegin || q > bloktop)
abort(3);
if (p == bloktop)
break;
if (busy(p))
us += q - p;
else
un += q - p;
if (p >= q)
abort(4);
p = q;
}
prs("un/used/avail ");
prn(un);
blank();
prn(us);
blank();
prn((char *)bloktop - brkbegin - (un + us));
newline();
}
#endif
size_t
blklen(char *q)
{
register struct blk *pp = (struct blk *)q;
register struct blk *p;
--pp;
p = (struct blk *)(Rcheat(pp->word) & ~BUSY);
return ((size_t)((long)p - (long)q));
}
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