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/*
* AT&T Unix 7th Edition memory allocation routines.
*
* Modified for ex by Gunnar Ritter, Freiburg i. Br., Germany,
* July 2000.
*
* Copyright(C) Caldera International Inc. 2001-2002. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* Redistributions of source code and documentation must retain the
* above copyright notice, this list of conditions and the following
* disclaimer.
* 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.
* All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed or owned by Caldera
* International, Inc.
* Neither the name of Caldera International, Inc. nor the names of
* other contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
* INTERNATIONAL, INC. AND CONTRIBUTORS ``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 CALDERA INTERNATIONAL, 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.
*
* @(#)malloc.c 1.19 (gritter) 2/20/05
*/
#ifdef VMUNIX
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include "config.h"
#ifdef LANGMSG
#include <nl_types.h>
extern nl_catd catd;
#else
#define catgets(a, b, c, d) (d)
#endif
/*
* Since ex makes use of sbrk(), the C library's version of malloc()
* must be avoided.
*
* In ex, malloc() calls sbrk() only one time with an argument of
* POOL. Ex itselves never uses malloc() internally, so POOL
* must be sufficient for library calls like setlocale() only.
*
* Known problem: If linking against ncurses, changing the terminal
* type repeatedly outruns the pool. Even that is not really a
* problem since the work continues with the old terminal type, so
* there is no need for a large pool here.
*/
#define POOL 32768
#ifdef debug
#define ASSERT(p) if(!(p))botch("p");else
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int
botch(char *s)
{
const char msg[] = "assertion botched\n";
write(2, msg, sizeof msg - 1);
/*printf("assertion botched: %s\n",s);*/
abort();
}
static int allock(void);
#else
#define ASSERT(p)
#endif
/* avoid break bug */
#ifdef pdp11
#define GRANULE 64
#else
#define GRANULE 0
#endif
/* C storage allocator
* circular first-fit strategy
* works with noncontiguous, but monotonically linked, arena
* each block is preceded by a ptr to the (pointer of)
* the next following block
* blocks are exact number of words long
* aligned to the data type requirements of ALIGN
* pointers to blocks must have BUSY bit 0
* bit in ptr is 1 for busy, 0 for idle
* gaps in arena are merely noted as busy blocks
* last block of arena (pointed to by alloct) is empty and
* has a pointer to first
* idle blocks are coalesced during space search
*
* a different implementation may need to redefine
* ALIGN, NALIGN, BLOCK, BUSY, INT
* where INT is integer type to which a pointer can be cast
*/
#define INT intptr_t
#define ALIGN intptr_t
#define NALIGN 1
#define WORD sizeof (union store)
#define BLOCK 1024 /* a multiple of WORD*/
#define BUSY ((intptr_t)1)
#ifdef NULL
#undef NULL
#endif
#define NULL 0
#define testbusy(p) ((INT)(p)&BUSY)
#define setbusy(p) (union store *)((INT)(p)|BUSY)
#define clearbusy(p) (union store *)((INT)(p)&~BUSY)
union store { union store *ptr;
ALIGN dummy[NALIGN];
INT callocsp; /*calloc clears an array of integers*/
};
static union store allocs[2]; /*initial arena*/
static union store *allocp; /*search ptr*/
static union store *alloct; /*arena top*/
static union store *allocx; /*for benefit of realloc*/
extern int error(char *, ...);
char *
poolsbrk(intptr_t inc)
{
static char *pool;
static intptr_t ps;
intptr_t os, ns;
if (pool == NULL)
if ((pool = sbrk(POOL)) == (char *)-1)
error(catgets(catd, 1, 241,
"No memory pool"));
if (inc == 0)
return pool + ps;
os = ps;
ns = ps + inc;
if (ns >= POOL)
error(catgets(catd, 1, 242,
"Memory pool exhausted"));
ps = ns;
return pool + os;
}
void *
malloc(size_t nbytes)
{
register union store *p, *q;
register int nw;
static int temp; /*coroutines assume no auto*/
if(allocs[0].ptr==0) { /*first time*/
allocs[0].ptr = setbusy(&allocs[1]);
allocs[1].ptr = setbusy(&allocs[0]);
alloct = &allocs[1];
allocp = &allocs[0];
}
nw = (nbytes+WORD+WORD-1)/WORD;
ASSERT(allocp>=allocs && allocp<=alloct);
ASSERT(allock());
for(p=allocp; ; ) {
for(temp=0; ; ) {
if(!testbusy(p->ptr)) {
while(!testbusy((q=p->ptr)->ptr)) {
int ua = p->ptr==allocp;
ASSERT(q>p&&q<alloct);
p->ptr = q->ptr;
if (ua)
allocp = p->ptr;
}
if(q>=p+nw && p+nw>=p)
goto found;
}
q = p;
p = clearbusy(p->ptr);
if(p>q)
ASSERT(p<=alloct);
else if(q!=alloct || p!=allocs) {
ASSERT(q==alloct&&p==allocs);
errno = ENOMEM;
return(NULL);
} else if(++temp>1)
break;
}
temp = ((nw+BLOCK/WORD)/(BLOCK/WORD))*(BLOCK/WORD);
q = (union store *)poolsbrk(0);
if(q+temp+GRANULE < q) {
errno = ENOMEM;
return(NULL);
}
q = (union store *)poolsbrk(temp*WORD);
if((INT)q == -1) {
errno = ENOMEM;
return(NULL);
}
ASSERT(q>alloct);
alloct->ptr = q;
if(q!=alloct+1)
alloct->ptr = setbusy(alloct->ptr);
alloct = q->ptr = q+temp-1;
alloct->ptr = setbusy(allocs);
}
found:
allocp = p + nw;
ASSERT(allocp<=alloct);
if(q>allocp) {
allocx = allocp->ptr;
allocp->ptr = p->ptr;
}
p->ptr = setbusy(allocp);
return((char *)(p+1));
}
/* freeing strategy tuned for LIFO allocation
*/
void
free(register void *ap)
{
register union store *p = ap;
if (ap == NULL)
return;
ASSERT(p>clearbusy(allocs[1].ptr)&&p<=alloct);
ASSERT(allock());
allocp = --p;
ASSERT(testbusy(p->ptr));
p->ptr = clearbusy(p->ptr);
ASSERT(p->ptr > allocp && p->ptr <= alloct);
}
/* realloc(p, nbytes) reallocates a block obtained from malloc()
* and freed since last call of malloc()
* to have new size nbytes, and old content
* returns new location, or 0 on failure
*/
void *
realloc(void *ap, size_t nbytes)
{
register union store *p = ap;
register union store *q;
union store *s, *t;
register size_t nw;
size_t onw;
if (p == NULL)
return malloc(nbytes);
if (nbytes == 0) {
free(p);
return NULL;
}
if(testbusy(p[-1].ptr))
free(p);
onw = p[-1].ptr - p;
q = malloc(nbytes);
if(q==NULL || q==p)
return(q);
s = p;
t = q;
nw = (nbytes+WORD-1)/WORD;
if(nw<onw)
onw = nw;
while(onw--!=0)
*t++ = *s++;
if(q<p && q+nw>=p)
(q+(q+nw-p))->ptr = allocx;
return(q);
}
#ifdef debug
int
allock(void)
{
#ifdef longdebug
register union store *p;
int x;
x = 0;
for(p= &allocs[0]; clearbusy(p->ptr) > p; p=clearbusy(p->ptr)) {
if(p==allocp)
x++;
}
ASSERT(p==alloct);
return(x==1|p==allocp);
#else
return(1);
#endif
}
#endif
/* calloc - allocate and clear memory block
*/
#define CHARPERINT (sizeof(INT)/sizeof(char))
void *
calloc(size_t num, size_t size)
{
register char *mp;
register INT *q;
register int m;
num *= size;
mp = malloc(num);
if(mp == NULL)
return(NULL);
q = (INT *) mp;
m = (num+CHARPERINT-1)/CHARPERINT;
while(--m >= 0)
*q++ = 0;
return(mp);
}
#ifdef notdef
/*ARGSUSED*/
void
cfree(char *p, size_t num, size_t size)
{
free(p);
}
/*
* Just in case ...
*/
char *
memalign(size_t alignment, size_t size)
{
return NULL;
}
char *
valloc(size_t size)
{
return NULL;
}
char *
mallinfo(void)
{
return NULL;
}
int
mallopt(void)
{
return -1;
}
#endif /* notdef */
#endif /* VMUNIX */