shithub: mq

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mq: fix some bugs and crashes

--- a/mq.c

+++ b/mq.c

@@ -11,8 +11,14 @@

 enum {

 	Qroot,

+	Maxqid,

 };

+enum {

+	Cclose,

+	Ctrunc,

+};

+

 struct Aux {

 	Mq	*q;

 	int	id;

@@ -35,8 +41,9 @@

 };

 struct Mq {

+	Ref;

 	Qid	qid;

-	int	count;

+	int	moribund;

 	usize	logsz;

 	Msg	*loghd;

 	Msg	*logtl;

@@ -55,12 +62,16 @@

 Mq	**queues;

 int	nqueues;

 vlong	maxlog = -1;

-vlong	queueid = Qroot + 1;

+vlong	queueid = Maxqid;

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

 char Einuse[] = "fid in use";

 char Eexist[] = "file already exists";

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

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

+char Eintr[] = "interrupted";

+char Enotdir[] = "not a directory";

+char Ebadcmd[] = "unknown command";

+char Enomem[] = "out of memory";

 void *

 emalloc(ulong n)

@@ -96,21 +107,7 @@

 	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;

@@ -121,7 +118,8 @@

 		m = q->loghd;

 		q->loghd = m->next;

 		q->logsz -= m->count;

-		msgunref(m);

+		if(decref(m) == 0)

+			free(m);

 	}

 	if(q->loghd == nil)

 		q->logtl = nil;

@@ -151,7 +149,7 @@

 	rd->hd = q->loghd;

 	rd->tl = q->logtl;

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

-		msgref(m);

+		incref(m);

 	return rd->id;

 }

@@ -214,12 +212,12 @@

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

 			*qid = f->qid;

 			return nil;

+		}else if((q = lookup(name)) != nil){

+			f->qid = q->qid;

+			*qid = f->qid;

+			return nil;

 		}

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

-			return Enoexist;

-		f->qid = q->qid;

-		*qid = f->qid;

-		return nil;

+		return Enoexist;

 	default:

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

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

@@ -226,7 +224,7 @@

 			*qid = f->qid;

 			return nil;

 		}

-		return "not a dir";

+		return Enotdir;

 	}	

 }

@@ -267,8 +265,24 @@

 void

 mqremove(Req *r)

 {

-	USED(r);

-	abort();

+	vlong path;

+	int i, o;

+

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

+	if(path == Qroot){

+		respond(r, Ebaduse);

+		return;

+	}

+	o = 0;

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

+		if(queues[i]->qid.path == path){

+			queues[i]->moribund = 1;

+			continue;

+		}

+		queues[o++] = queues[i];

+	}

+	nqueues--;

+	respond(r, nil);

 }

 void

@@ -311,13 +325,14 @@

 		if(q->rd[i].tl != nil)

 			q->rd[i].tl->next = m;

 		q->rd[i].tl = m;

-		msgref(m);

+		incref(m);

 	}

 	if(q->loghd == nil)

 		q->loghd = m;

 	if(q->logtl != nil)

 		q->logtl->next = m;

-	q->logtl = msgref(m);

+	incref(m);

+	q->logtl = m;

 	q->logsz += m->count;

 	q->logtl = m;

@@ -369,7 +384,8 @@

 		rd->hd = m->next;

 		if(rd->hd == nil)

 			rd->tl = nil;

-		msgunref(m);

+		if(decref(m) == 0)

+			free(m);

 	}

 }

@@ -419,7 +435,8 @@

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

 	a = emalloc(sizeof(Aux));

 	if(p != Qroot){

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

+		incref(queues[p-Maxqid]);

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

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

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

 		r->fid->aux = a;

@@ -497,4 +514,5 @@

 	}ARGEND;

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

+	exits(nil);

 }