shithub: mq

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initial commit

--- /dev/null

+++ b/mkfile

@@ -1,0 +1,6 @@

+</$objtype/mkfile

+

+TARG=mq

+OFILES=mq.$O

+

+</sys/src/cmd/mkone

--- /dev/null

+++ b/mq.c

@@ -1,0 +1,464 @@

+#include <u.h>

+#include <libc.h>

+#include <fcall.h>

+#include <thread.h>

+#include <9p.h>

+

+typedef struct Mq Mq;

+typedef struct Msg Msg;

+typedef struct Aux Aux;

+

+enum {

+	Qroot,

+};

+

+struct Aux {

+	Mq	*q;

+	int	id;

+};

+

+struct Msg {

+	Ref;

+	Msg	*next;

+	int	count;

+	char	data[];

+};

+

+struct Mq {

+	Qid	qid;

+	int	count;

+	usize	logsz;

+	Msg	*loghd;

+	Msg	*logtl;

+	Msg	*hd;

+	Msg	*tl;

+

+	int	nrd;

+	int	*rd;

+	Msg	**rhd;

+	Msg	**rtl;

+	Req	**wait;

+

+	char	*name;

+	char	*user;

+	char	*group;

+	int	mode;

+};

+

+Mq	**queues;

+int	nqueues;

+vlong	maxlog = -1;

+vlong	queueid = Qroot + 1;

+

+char Ebaduse[] = "invalid use of fd";

+char Einuse[] = "fid in use";

+char Eexist[] = "file already exists";

+char Enoexist[] = "file does not exists";

+

+void *

+emalloc(ulong n)

+{

+	void *v;

+	

+	v = mallocz(n, 1);

+	if(v == nil)

+		sysfatal("malloc: %r");

+	setmalloctag(v, getcallerpc(&n));

+	return v;

+}

+

+void *

+erealloc(void *p, ulong n)

+{

+	void *v;

+	

+	v = realloc(p, n);

+	if(v == nil)

+		sysfatal("realloc: %r");

+	setmalloctag(v, getcallerpc(&p));

+	return v;

+}

+

+char*

+estrdup(char *s)

+{

+	s = strdup(s);

+	if(s == nil)

+		sysfatal("strdup: %r");

+	setmalloctag(s, getcallerpc(&s));

+	return s;

+}

+

+Msg*

+msgref(Msg *m)

+{

+	incref(m);

+	return m;

+}

+

+void

+msgunref(Msg *m)

+{

+	if(decref(m) == 0)

+		free(m);

+}

+

+void

+trimlog(Mq *q)

+{

+	Msg *m, *n;

+

+	if(maxlog < 0)

+		return;

+	n = nil;

+	for(m = q->loghd; m != nil && q->logsz >= maxlog; m = n){

+		n = m->next;

+		q->logsz -= m->count;

+		msgunref(m);

+	}

+	q->loghd = n;

+	if(m == nil)

+		q->logtl = nil;

+}

+

+int

+subscribe(Mq *q)

+{

+	Msg *m;

+	int i;

+

+	for(i = 0; i < q->nrd; i++)

+		if(q->rd[i] != -1)

+			return i;

+	q->rd = erealloc(q->rd, (q->nrd+1)*sizeof(*q->rd));

+	q->wait = erealloc(q->rhd, (q->nrd+1)*sizeof(*q->wait));

+	q->rhd = erealloc(q->rhd, (q->nrd+1)*sizeof(*q->rhd));

+	q->rtl = erealloc(q->rtl, (q->nrd+1)*sizeof(*q->rtl));

+	q->wait[q->nrd] = nil;

+	q->rhd[q->nrd] = q->loghd;

+	q->rtl[q->nrd] = q->logtl;

+	for(m = q->loghd; m != nil; m = m->next)

+		msgref(m);

+	return q->nrd++;

+}

+

+Mq*

+lookup(char *name)

+{

+	int i;

+

+	for(i = 0; i < nqueues; i++)

+		if(strcmp(queues[i]->name, name) == 0)

+			return queues[i];

+	return nil;

+}

+

+void

+qstat(Dir *d, Mq *q)

+{

+	d->name = estrdup9p(q->name);

+	d->uid = estrdup9p("glenda");

+	d->gid = estrdup9p("glenda");

+	d->muid = estrdup9p("glenda");

+	d->qid = q->qid;

+	d->mtime = 0;

+	d->atime = 0;

+	d->mode = q->mode;

+}

+

+int

+rootgen(int i, Dir *d, void *)

+{

+	if(i >= nqueues)

+		return -1;

+	qstat(d, queues[i]);

+	return 0;

+}

+	

+

+char*

+mqclone(Fid *old, Fid *new)

+{

+	Aux *o, *n;

+

+	o = old->aux;

+	if(o != nil){

+		n = emalloc(sizeof(Aux));

+		n->q = o->q;

+		n->id = subscribe(o->q);

+		new->aux = n;

+	}

+	return nil;

+}

+

+char*

+mqwalk1(Fid *f, char *name, Qid *qid)

+{

+	Mq *q;

+

+	switch(f->qid.path){

+	case Qroot:

+		if(strcmp(name, "..") == 0){

+			*qid = f->qid;

+			return nil;

+		}

+		if((q = lookup(name)) == nil)

+			return Enoexist;

+		f->qid = q->qid;

+		*qid = f->qid;

+		return nil;

+	default:

+		if(strcmp(name, "..") == 0){

+			f->qid = (Qid){Qroot, 0, QTDIR};

+			*qid = f->qid;

+			return nil;

+		}

+		return "not a dir";

+	}	

+}

+

+void

+mqstat(Req *r)

+{

+	switch(r->fid->qid.path){

+	case Qroot:

+		r->d.uid = estrdup9p("glenda");

+		r->d.gid = estrdup9p("glenda");

+		r->d.muid = estrdup9p("glenda");

+		r->d.qid = r->fid->qid;

+		r->d.mtime = 0;

+		r->d.atime = 0;

+		r->d.mode = 0755;

+		break;

+	default:

+		qstat(&r->d, ((Aux*)r->fid->aux)->q);

+	}

+	respond(r, nil);

+}

+

+void

+mqflush(Req *r)

+{

+	Req *w;

+	Aux *a;

+

+	if((a = r->oldreq->fid->aux) != nil){

+		w = a->q->wait[a->id];

+		if(w != nil)

+			respond(w, "interrupted");

+		a->q->wait[a->id] = nil;

+	}

+	respond(r, nil);

+}

+

+void

+mqremove(Req *r)

+{

+	USED(r);

+	abort();

+}

+

+void

+mqwrite(Req *r)

+{

+	Msg *m;

+	Req *rr;

+	Aux *a;

+	Mq *q;

+	int i;

+

+	if((a = r->fid->aux) == nil){

+		respond(r, Ebaduse);

+		return;

+	}

+	q = a->q;

+	m = emalloc(sizeof(Msg) + r->ifcall.count);

+	m->count = r->ifcall.count;

+	memcpy(m->data, r->ifcall.data, m->count);

+	m->next = nil;

+	for(i = 0; i < q->nrd; i++){

+		rr = q->wait[i];

+		if(rr != nil){

+			rr->ofcall.data = r->ifcall.data;

+			rr->ofcall.count = r->ifcall.count;

+			respond(rr, nil);

+			q->wait[i] = nil;

+		}else{

+			if(q->rhd[i] == nil)

+				q->rhd[i] = m;

+			if(q->rtl[i] != nil)

+				q->rtl[i]->next = m;

+			q->rtl[i] = m;

+			msgref(m);

+		}

+	}

+	if(q->loghd == nil)

+		q->loghd = m;

+	if(q->logtl != nil)

+		q->logtl->next = m;

+	q->logtl = msgref(m);

+	q->logsz += m->count;

+	q->logtl = m;

+

+	trimlog(q);

+	q->qid.vers++;

+	r->ofcall.count = r->ifcall.count;

+	respond(r, nil);

+}

+

+void

+mqread(Req *r)

+{

+	Aux *a;

+	Msg *m;

+	Mq *q;

+

+	if(r->fid->qid.path == Qroot){

+		dirread9p(r, rootgen, nil);

+		respond(r, nil);

+		return;

+	}

+	if((a = r->fid->aux) == nil){

+		respond(r, Ebaduse);

+		return;

+	}

+	q = a->q;

+	if(q->rhd[a->id] != nil){

+		m = q->rhd[a->id];

+		r->ofcall.data = m->data;

+		r->ofcall.count = m->count;

+		respond(r, nil);

+		q->rhd[a->id] = m->next;

+		if(q->rhd[a->id] == nil)

+			q->rtl[a->id] = nil;

+		msgunref(m);

+		return;

+	}

+	q->wait[a->id] = r;

+}

+

+void

+mqcreate(Req *r)

+{

+	Aux *a;

+	Mq *q;

+	int m;

+

+	if(lookup(r->ifcall.name) != nil){

+		respond(r, Eexist);

+		return;

+	}

+	m = r->ifcall.mode & OMASK;

+	q = emalloc(sizeof(Mq));

+	q->name = estrdup(r->ifcall.name);

+	q->mode = r->ifcall.mode;

+	q->qid.path = queueid++;

+	q->qid.vers = 0;

+	q->qid.type = QTFILE;

+	a = emalloc(sizeof(Aux));

+	a->q = q;

+	if(m == OREAD || m == ORDWR || m == OEXEC)

+		a->id = subscribe(q);

+	r->ofcall.qid = q->qid;

+	r->fid->qid = q->qid;

+	r->fid->aux = a;

+	queues = erealloc(queues, ++nqueues*sizeof(Mq*));

+	queues[nqueues-1] = q;

+

+	respond(r, nil);

+}

+

+void

+mqopen(Req *r)

+{

+	Aux *a;

+	vlong p;

+	int m;

+

+	if(r->fid->aux != nil){

+		respond(r, Einuse);

+		return;

+	}

+	m = r->ifcall.mode & OMASK;

+	p = r->fid->qid.path;

+	a = emalloc(sizeof(Aux));

+	if(p != Qroot){

+		a->q = queues[p-1];

+		if(m == OREAD || m == ORDWR || m == OMASK)

+			a->id = subscribe(a->q);

+		r->fid->aux = a;

+	}

+	r->ofcall.qid = r->fid->qid;

+	respond(r, nil);

+}

+

+void

+destroyfid(Fid *f)

+{

+	Aux *a;

+	int m;

+

+	a = f->aux;

+	m = f->omode & OMASK;

+	if(m != OREAD && m != ORDWR && m != OEXEC)

+		return;

+	if(a != nil)

+		a->q->rd[a->id] = -1;

+}

+

+void

+mqattach(Req *r)

+{

+	r->ofcall.qid = (Qid){Qroot, 0, QTDIR};

+	r->fid->qid = r->ofcall.qid;

+	r->fid->aux = nil;

+	respond(r, nil);

+}

+

+Srv mq  = {

+	.attach=mqattach,

+	.open=mqopen,

+	.create=mqcreate,

+	.read=mqread,

+	.write=mqwrite,

+	.remove=mqremove,

+	.flush=mqflush,

+	.stat=mqstat,

+	.walk1=mqwalk1,

+	.clone=mqclone,

+	.destroyfid=destroyfid,

+};

+

+void

+usage(void)

+{

+	fprint(2, "usage: %s [-s srv] [-m mtpt]\n", argv0);

+	exits("usage");

+}

+

+void

+main(int argc, char **argv)

+{

+	char *srvname, *mntpt;

+

+	srvname = nil;

+	mntpt = "/mnt/mq";

+	ARGBEGIN{

+	case 'd':

+		chatty9p++;

+		break;

+	case 's':

+		srvname=EARGF(usage());

+		break;

+	case 'm':

+		mntpt = EARGF(usage());

+		break;

+	case 'r':

+		maxlog = atoi(EARGF(usage()));

+		break;

+	default:

+		usage();

+	}ARGEND;

+

+	postmountsrv(&mq, srvname, mntpt, MCREATE|MREPL);

+}