#include "../h/param.h"#include "../h/systm.h"#include "../h/conf.h"#include "../h/buf.h"#define	XPRI	30#define	NBLOCKS	10int	bwaiting, wcount;struct	buf *bufps[NBLOCKS];char	*nbase[NBLOCKS];	/* normal allocations */short	nmap[NBLOCKS];		/* 1 bit == 32 bytes */char log[] ={0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4};#define	FULL	-1#define	LOCK	s = spl6()#define	UNLOCK	splx(s)/* * getepack: get empty packet * with size specified by bitmask. */char *getepack(bits){register i;int	s, savbits;char	**base;short	*map;	base = nbase; map = nmap;	savbits = bits;	/*	 * search for space	 */	LOCK;	for(;;) {		if (bits == FULL)			goto force;		for(i=0; i<NBLOCKS; i++) {			register m;			register unsigned n;			register offset;			m = map[i];			if (m==FULL || base[i]==NULL)				continue;			if (bits == 1) {				n = m;				m |= m+1;				n = m-n;				for (offset=0; n > 16; n >>= 4) 					offset += 4;				offset += log[n];			} else {				bits = savbits;				for(n=17; --n; bits <<= 1)					if ((m&bits)==0)						goto found;				continue;			found:				offset = 16-n;				m |= bits;			}			map[i] = m;			UNLOCK;			return(base[i] + 32*offset);		}		/*		 * grab another block from the system		 */	force:		for(i=0;i<NBLOCKS;i++) {			register struct buf *bp;			if (bufps[i]!=NULL)				continue;			bufps[i] = bp = geteblk();			bp->b_flags |= B_PACK;			bp->b_flags |= B_PBUSY;			map[i] = bits;			base[i] = bp->b_un.b_addr;			UNLOCK;			return(bp->b_un.b_addr);		}		/*		 * sleep until something is released		 */		bwaiting++;		wcount++;		sleep((caddr_t)&bwaiting, XPRI);		bwaiting--;	}}/* * freepack: release space beginning * at address p with length specified * by bits. */freepack(p, bits)char *p;{register i, d, s;char	**base;short	*map;	if (p==NULL)		return;	LOCK;	base = nbase; map = nmap;	for(i=0;i<NBLOCKS;i++) {		d = p-base[i];		if (d>=0 && d<=512) 			goto found;	}	goto out;found:	d >>= 5;	d = (bits<<d);	map[i] &= ~d;	if (map[i]==0) {		register struct buf *bp;		bp = bufps[i];		bp->b_flags &= ~B_PBUSY;		base[i] = NULL;		bufps[i] = NULL;		brelse(bp);	}	if (bwaiting)		wakeup((caddr_t)&bwaiting);out:	splx(s);}/* * integer to bitmap conversion */dtom(d)register d;{register m;	m = 1;	while (d>32) {		d -= 32;		m |= m+1;	}	return(m);}#define NRECS	160int reclist[NRECS];int recbits[NRECS];