/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include	<u.h>#include	<libc.h>#include	<bio.h> static	Biobufhdr*	wbufs[20];static	int		atexitflag; staticvoidbatexit(void){	Biobufhdr *bp;	int i; 	for(i=0; i<nelem(wbufs); i++) {		bp = wbufs[i];		if(bp != 0) {			wbufs[i] = 0;			Bflush(bp);		}	}} staticvoiddeinstall(Biobufhdr *bp){	int i; 	for(i=0; i<nelem(wbufs); i++)		if(wbufs[i] == bp)			wbufs[i] = 0;} staticvoidinstall(Biobufhdr *bp){	int i; 	deinstall(bp);	for(i=0; i<nelem(wbufs); i++)		if(wbufs[i] == 0) {			wbufs[i] = bp;			break;		}	if(atexitflag == 0) {		atexitflag = 1;		atexit(batexit);	}} intBinits(Biobufhdr *bp, int f, int mode, uchar *p, int size){ 	p += Bungetsize;	/* make room for Bungets */	size -= Bungetsize; 	switch(mode&~(OCEXEC|ORCLOSE|OTRUNC)) {	default:		fprint(2, "Binits: unknown mode %d\n", mode);		return Beof; 	case OREAD:		bp->state = Bractive;		bp->ocount = 0;		break; 	case OWRITE:		install(bp);		bp->state = Bwactive;		bp->ocount = -size;		break;	}	bp->bbuf = p;	bp->ebuf = p+size;	bp->bsize = size;	bp->icount = 0;	bp->gbuf = bp->ebuf;	bp->fid = f;	bp->flag = 0;	bp->rdline = 0;	bp->offset = 0;	bp->runesize = 0;	return 0;}  intBinit(Biobuf *bp, int f, int mode){	return Binits(bp, f, mode, bp->b, sizeof(bp->b));} Biobuf*Bopen(char *name, int mode){	Biobuf *bp;	int f; 	switch(mode&~(OCEXEC|ORCLOSE|OTRUNC)) {	default:		fprint(2, "Bopen: unknown mode %#x\n", mode);		return 0;	case OREAD:		f = open(name, mode);		break;	case OWRITE:		f = create(name, mode, 0666);		break;	}	if(f < 0)		return 0;	bp = malloc(sizeof(Biobuf));	Binits(bp, f, mode, bp->b, sizeof(bp->b));	bp->flag = Bmagic;			/* mark bp open & malloced */	return bp;} intBterm(Biobufhdr *bp){	int r; 	deinstall(bp);	r = Bflush(bp);	if(bp->flag == Bmagic) {		bp->flag = 0;		close(bp->fid);		bp->fid = -1;			/* prevent accidents */		free(bp);	}	/* otherwise opened with Binit(s) */	return r;}