#include "u.h"#include "../port/lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "../port/error.h" typedef struct Aux Aux; enum {	Qroot,	Qctl,	Qevents,	Nfiles = 3,	Evsize = 256,	Nmon = 10, 	/* c->dev types */	Droot = 0,	Dmon = -1, 	Debug = 1,}; struct Aux{	union {		Queue *q;		/* root holds the event queue */		Chan *c;		/* monitored Chan */	};	ushort type;	/* real type for monitored Chan */};			 Chan *monitored[Nmon];	/* monitored Chans, indexed by monitor Chan dev */ Dirtab fopsdir[] = {	".",		{Qroot,0,QTDIR}, 0,	DMDIR|0500,	"ctl",		{Qctl}, 0, 0600,	"events",	{Qevents}, 0, 0600,}; static voidfopinit(void){} #define dbg if(Debug)print voiddbgchan(Chan *c){	Aux *a; 	if(c == nil)		return; 	dbg("chan @ %p %s dev %lud type %d mchan %s", 		c, chanpath(c), c->dev, c->type, chanpath(c->mchan));	if(c->aux){		a = c->aux;		dbg(" aux[ c %s type %d]", chanpath(a->c), a->type);	}	dbg("\n");} /* Every root of the tree has a new event queue */static Chan*fopattach(char *spec){	Chan *c;	Queue *q;	Aux *a;	ulong dev; 	dev = Droot;			/* root fop */	if(spec && *spec)		dev = atoi(spec)+1;	print("fopattach: spec %s dev %lud\n", spec, dev); 	c = devattach('O', spec);	a = malloc(sizeof(Aux)); 	if(dev == Droot){		q = qopen(Evsize, 0, 0, 0); /* event queue */		if(q == 0){			free(a);			exhausted("memory for queue");		}		a->q = q;	}else{		a->c = monitored[dev];		print("fopattach: "), dbgchan(a->c);	} 	mkqid(&c->qid, Qroot, 0, QTDIR);	c->aux = a;	c->dev = dev;	return c;} static intfopgen(Chan *c, char*, Dirtab *tab, int ntab, int i, Dir *dp){	Qid q; 	if(i == DEVDOTDOT){		dbg("fopgen: dotdot\n");		devdir(c, c->qid, "#O", 0, eve, DMDIR|0555, dp);		return 1;	} 	i++;	/* skip . */	if(tab == 0 || i >= ntab)		return -1; 	tab += i;	switch((ulong)tab->qid.path){	case Qctl:		dbg("fopgen: ctl\n");		break;	case Qevents:		dbg("fopgen: events\n");		break;	default:		break;	}	mkqid(&q, tab->qid.path, 0, QTFILE);	devdir(c, q, tab->name, 0, eve, tab->perm, dp);	return 1;} static Walkqid*fopwalk(Chan *c, Chan *nc, char **name, int nname){	Chan *mchan, *tc;	Walkqid *wq;	Aux *a;	int i; 	print(">> fopwalk: "), dbgchan(c);	for(i=0; i < nname; i++)		dbg("fopwalk: name[%d] %s\n", i, name[i]); 	switch(c->dev){	case Droot:			/* walk to the device's files */		return devwalk(c, nc, name, nname, fopsdir, Nfiles, fopgen);	case Dmon:		/* walk to the files being monitored */		a = c->aux;		dbg("fopwalk: [Dmon] walking via "), dbgchan(a->c);		//return nil; 	/*	wq = devtab[a->type]->walk(a->c, nc, name, nname);		if(wq == nil){			print("could not walk\n");			return nil;		}		return wq;	*/		return devwalk(a->c, nc, name, nname, 0, 0, 0); 	default:		/*		 * more os less a transition state, we associate		 * our device, say #O0, with a dir in the namespace		 */		a = c->aux;		print("fopwalk: aux "), dbgchan(a->c);		mchan = a->c->mchan;		tc = a->c; 		wq = devwalk(a->c, nc, name, nname, 0, 0, 0);		if(wq == nil){			print("could not walk\n");			return nil;		} 		a = malloc(sizeof(Aux));		if(a == nil)			exhausted("fopwalk: no memory for Aux"); 		wq->clone->aux = a;		a->type = wq->clone->type;		a->c = tc;		a->c->type = a->type; 		/* patch dev for new Chan in order for us to own it */		wq->clone->dev = Dmon;		wq->clone->type = c->type;		wq->clone->mchan = mchan;		return wq;	}	// not reached	return devwalk(c, nc, name, nname, fopsdir, Nfiles, fopgen);} static intfopstat(Chan *c, uchar *db, int n){	Dir dir;	Aux *a; 	dbg(">> fopstat "), dbgchan(c); 	switch((ulong)c->qid.path){	case Qroot:		devdir(c, c->qid, ".", 0, eve, DMDIR|0555, &dir);		break;	case Qctl:		devdir(c, c->qid, "ctl", 0, eve, 0600, &dir);		break;	case Qevents:		devdir(c, c->qid, "events", qlen((Queue*)c->aux), eve, 0600, &dir);		break;	default:		a = c->aux;		return devtab[a->type]->stat(c, db, n);	}	n = convD2M(&dir, db, n);	if(n < BIT16SZ)		error(Eshortstat);	return n;} static Chan*fopopen(Chan *c, int omode){	print("fopopen\n");	if(c->qid.type == QTDIR){		if(omode != OREAD)			error(Eisdir);		c->mode = omode;		c->flag |= COPEN;		c->offset = 0;		return c;	} 	c->mode = openmode(omode);	c->flag |= COPEN;	c->offset = 0;	return c;} static voidfopclose(Chan*){	print("fopclose\n");} static longfopread(Chan *c, void *va, long n, vlong off){	Chan *cnew;	print("fopread\n"); 	USED(off);	switch((ulong)c->qid.path){	case Qroot:		return devdirread(c, va, n, fopsdir, Nfiles, fopgen);	case Qctl:		/* from sysfile.c:/^bindmount */		monitored[1] = namec("/cfg", Amount, 0, 0);		cnew = namec("#O0", Abind, 0, 0);		cmount(&cnew, monitored[1], MREPL, nil); // check errors		return 0;	case Qevents:		return qread((Queue*)c->aux, va, n);	default:		panic("fopread");	}	return -1; /* not reached */} static longfopwrite(Chan *c, void *va, long n, vlong off){	USED(c); USED(va); USED(n); USED(off);	print("fopwrite\n");	switch((ulong)c->qid.path){	case Qctl:		return qwrite((Queue*)c->aux, va, n);	case Qevents:		return -1;	default:		panic("fopwrite");	}	return 0;}  Dev fopdevtab = {	'O',	"fop", 	devreset,	fopinit,	devshutdown,	fopattach,	fopwalk,	fopstat,	fopopen,	devcreate,	fopclose,	fopread,	devbread,	fopwrite,	devbwrite,	devremove,	devwstat,};