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/* $OpenBSD: malloc.c,v 1.2 1996/03/04 10:37:12 mickey Exp $ */
/* $NetBSD: malloc.c,v 1.4 1994/06/29 06:41:10 cgd Exp $ */
/*
* This code is such a kludge that I don't want to put my name on it.
* It was a ridiculously fast hack and needs rewriting.
* However it does work...
*/
/*
* a simple malloc
* it might be brain-damaged but for the purposes of xebec
* it's a whole lot faster than the c library malloc
*/
#include <stdio.h>
#include "malloc.h"
#include "debug.h"
#define CHUNKSIZE 4096*2
static char *hiwat, *highend;
int bytesmalloced=0;
int byteswasted = 0;
init_alloc()
{
#ifdef LINT
hiwat = 0;
highend = 0;
#else LINT
extern char *sbrk();
hiwat = (char *) sbrk(0);
hiwat = (char *)((unsigned)(hiwat + 3) & ~0x3);
highend = hiwat;
#endif LINT
}
HIWAT(s)
char *s;
{
IFDEBUG(M)
fprintf(stdout, "HIWAT 0x%x %s\n", hiwat,s);
fflush(stdout);
ENDDEBUG
}
#define MIN(x,y) ((x<y)?x:y)
char *Malloc(x)
int x;
{
char *c;
extern char *sbrk();
static int firsttime=1;
int total = x;
int first_iter = 1;
char *returnvalue;
IFDEBUG(N)
fprintf(stdout, "Malloc 0x%x, %d, bytesmalloced %d\n",
total,total, bytesmalloced);
fflush(stdout);
ENDDEBUG
IFDEBUG(M)
fprintf(stdout, "Malloc 0x%x, %d, hiwat 0x%x\n",
total,total, hiwat);
fflush(stdout);
ENDDEBUG
if(firsttime) {
hiwat = sbrk(0);
if(((unsigned)(hiwat) & 0x3)) {
bytesmalloced = 4 - (int) ((unsigned)(hiwat) & 0x3);
hiwat = sbrk( bytesmalloced );
} else
bytesmalloced = 0;
firsttime = 0;
highend = hiwat;
}
while( total ) {
x = MIN(CHUNKSIZE, total);
if(total != x) {
IFDEBUG(N)
fprintf(stdout, "BIG Malloc tot %d, x %d, left %d net %d\n",
total,x, total-x, bytesmalloced);
fflush(stdout);
ENDDEBUG
}
if ( (hiwat + x) > highend) {
c = sbrk(CHUNKSIZE);
IFDEBUG(M)
fprintf(stdout, "hiwat 0x%x, x 0x%x, highend 0x%x, c 0x%x\n",
hiwat, x, highend, c);
fflush(stdout);
ENDDEBUG
if( c == (char *) -1 ) {
fprintf(stderr, "Ran out of memory!\n");
Exit(-1);
}
if(first_iter) {
returnvalue = c;
first_iter = 0;
}
bytesmalloced += CHUNKSIZE;
IFDEBUG(m)
if (highend != c) {
fprintf(OUT, "warning: %d wasted bytes!\n", highend - hiwat);
fprintf(OUT, " chunksize 0x%x, x 0x%x \n", CHUNKSIZE, x);
}
ENDDEBUG
highend = c + CHUNKSIZE;
hiwat = c;
}
c = hiwat;
if(first_iter) {
returnvalue = c;
first_iter = 0;
}
hiwat += x;
total -= x;
}
if((unsigned)hiwat & 0x3) {
byteswasted += (int)((unsigned)(hiwat) & 0x3);
hiwat = (char *)((unsigned)(hiwat + 3) & ~0x3);
}
IFDEBUG(M)
fprintf(stdout, "Malloc = 0x%x, bytesm 0x%x, wasted 0x%x, hiwat 0x%x\n",
returnvalue, bytesmalloced, byteswasted, hiwat);
ENDDEBUG
IFDEBUG(N)
fprintf(stdout, "Malloc returns 0x%x, sbrk(0) 0x%x\n", returnvalue, sbrk(0));
fflush(stdout);
ENDDEBUG
return(returnvalue);
}
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