142 lines
2.9 KiB
C
142 lines
2.9 KiB
C
/* $NetBSD: malloc.c,v 1.10 2005/12/11 12:25:16 christos Exp $ */
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/*
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* This code is such a kludge that I don't want to put my name on it.
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* It was a ridiculously fast hack and needs rewriting.
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* However it does work...
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*/
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/*
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* a simple malloc
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* it might be brain-damaged but for the purposes of xebec
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* it's a whole lot faster than the c library malloc
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: malloc.c,v 1.10 2005/12/11 12:25:16 christos Exp $");
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#include <stdio.h>
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#include "malloc.h"
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#include "debug.h"
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#include "main.h"
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#define CHUNKSIZE 4096*2
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static char *hiwat, *highend;
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int bytesmalloced=0;
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int byteswasted = 0;
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void
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init_alloc()
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{
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#ifdef LINT
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hiwat = 0;
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highend = 0;
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#else /* !LINT */
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extern char *sbrk();
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hiwat = (char *) sbrk(0);
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hiwat = (char *)((unsigned)(hiwat + 3) & ~0x3);
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highend = hiwat;
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#endif /* LINT */
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}
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void
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HIWAT(s)
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char *s;
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{
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IFDEBUG(M)
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fprintf(stdout, "HIWAT %p %s\n", hiwat,s);
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fflush(stdout);
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ENDDEBUG
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}
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#define MIN(x,y) ((x<y)?x:y)
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char *Malloc(x)
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int x;
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{
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char *c;
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extern char *sbrk();
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static int firsttime=1;
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int total = x;
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int first_iter = 1;
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char *returnvalue;
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IFDEBUG(N)
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fprintf(stdout, "Malloc 0x%x, %d, bytesmalloced %d\n",
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total,total, bytesmalloced);
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fflush(stdout);
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ENDDEBUG
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IFDEBUG(M)
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fprintf(stdout, "Malloc 0x%x, %d, hiwat %p\n",
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total,total, hiwat);
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fflush(stdout);
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ENDDEBUG
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if(firsttime) {
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hiwat = sbrk(0);
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if(((unsigned)(hiwat) & 0x3)) {
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bytesmalloced = 4 - (int) ((unsigned)(hiwat) & 0x3);
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hiwat = sbrk( bytesmalloced );
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} else
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bytesmalloced = 0;
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firsttime = 0;
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highend = hiwat;
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}
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while( total ) {
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x = MIN(CHUNKSIZE, total);
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if(total != x) {
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IFDEBUG(N)
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fprintf(stdout, "BIG Malloc tot %d, x %d, left %d net %d\n",
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total,x, total-x, bytesmalloced);
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fflush(stdout);
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ENDDEBUG
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}
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if ( (hiwat + x) > highend) {
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c = sbrk(CHUNKSIZE);
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IFDEBUG(M)
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fprintf(stdout, "hiwat %p, x 0x%x, highend %p, c %p\n",
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hiwat, x, highend, c);
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fflush(stdout);
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ENDDEBUG
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if( c == (char *) -1 ) {
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fprintf(stderr, "Ran out of memory!\n");
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Exit(-1);
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}
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if(first_iter) {
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returnvalue = c;
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first_iter = 0;
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}
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bytesmalloced += CHUNKSIZE;
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IFDEBUG(m)
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if (highend != c) {
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fprintf(OUT, "warning: %d wasted bytes!\n", highend - hiwat);
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fprintf(OUT, " chunksize 0x%x, x 0x%x \n", CHUNKSIZE, x);
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}
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ENDDEBUG
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highend = c + CHUNKSIZE;
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hiwat = c;
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}
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c = hiwat;
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if(first_iter) {
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returnvalue = c;
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first_iter = 0;
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}
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hiwat += x;
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total -= x;
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}
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if((unsigned)hiwat & 0x3) {
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byteswasted += (int)((unsigned)(hiwat) & 0x3);
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hiwat = (char *)((unsigned)(hiwat + 3) & ~0x3);
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}
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IFDEBUG(M)
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fprintf(stdout, "Malloc = %p, bytesm 0x%x, wasted 0x%x, hiwat %p\n",
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returnvalue, bytesmalloced, byteswasted, hiwat);
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ENDDEBUG
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IFDEBUG(N)
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fprintf(stdout, "Malloc returns %p, sbrk(0) %p\n", returnvalue, sbrk(0));
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fflush(stdout);
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ENDDEBUG
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return(returnvalue);
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}
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