#include	"u.h"#include	"lib.h"#include	"mem.h"#include	"dat.h"#include	"fns.h" static	char	bbarena[10000];static	char	bbused[10]; void*bbmalloc(int n){	char *a;	int s, i; 	s = splhi();	a = memchr(bbused, 0, sizeof(bbused));	if(a) {		i = a - bbused;		a = bbarena + i*n;		if(a+n <= bbarena+sizeof(bbarena)) {			bbused[i] = 1;			splx(s);			return a;		}	}	splx(s);	print("too many bbmallocs\n");	return bbarena;} voidbbfree(void *va, int n){	int s, i; 	s = splhi();	i = ((char*)va - bbarena) /n;	if(i >= 0 && i < sizeof(bbused) && bbused[i]){		bbused[i] = 0;		splx(s);		return;	}	splx(s);	print("sanity bbfree\n");} void*bbdflush(void *p, int n){	return p;}