rio: fix deadlock

we can't really change the Window *input from
outside the winctl() thread. the problem is
that the window might end up reading the
mouse (scroll, select) which makes the w->cctl
channel block once you try to talk to the
window again (from the mousethread). this also
means we have to coordinate window switchin
from the winctl proc waiting for the current
window to release the input and then take over.
thers a new Winctl message Topped that basically
does that now using Wakeup and a chan to
synchronize.

5 files changed, 71 insertions, 47 deletions

diff --git a/sys/src/cmd/rio/dat.h b/sys/src/cmd/rio/dat.h
index 363be0256..690bd4168 100644
--- a/sys/src/cmd/rio/dat.h
+++ b/sys/src/cmd/rio/dat.h
@@ -61,13 +61,14 @@ enum	/* control messages */
 	Wakeup,
 	Reshaped,
 	Moved,
+	Topped,
+	Repaint,
 	Refresh,
 	Movemouse,
 	Rawon,
 	Rawoff,
 	Holdon,
 	Holdoff,
-	Repaint,
 	Deleted,
 	Exited,
 };
@@ -76,7 +77,7 @@ struct Wctlmesg
 {
 	int		type;
 	Rectangle	r;
-	Image	*image;
+	void		*p;
 };
 
 struct Conswritemesg
@@ -132,7 +133,7 @@ struct Window
 	Mousectl		mc;
 	Mouseinfo	mouse;
 	Channel		*ck;			/* chan(char*) */
-	Channel		*cctl;		/* chan(Wctlmesg)[20] */
+	Channel		*cctl;		/* chan(Wctlmesg)[4] */
 	Channel		*conswrite;	/* chan(Conswritemesg) */
 	Channel		*consread;	/* chan(Consreadmesg) */
 	Channel		*mouseread;	/* chan(Mousereadmesg) */
@@ -188,8 +189,7 @@ char*	wcontents(Window*, int*);
 int		wbswidth(Window*, Rune);
 int		wclickmatch(Window*, int, int, int, uint*);
 int		wclose(Window*);
-int		wctlmesg(Window*, int, Rectangle, Image*);
-int		wctlmesg(Window*, int, Rectangle, Image*);
+int		wctlmesg(Window*, int, Rectangle, void*);
 uint		wbacknl(Window*, uint, uint);
 uint		winsert(Window*, Rune*, int, uint);
 void		waddraw(Window*, Rune*, int);
@@ -213,7 +213,7 @@ void		wresize(Window*, Image*, int);
 void		wscrdraw(Window*);
 void		wscroll(Window*, int);
 void		wselect(Window*);
-void		wsendctlmesg(Window*, int, Rectangle, Image*);
+void		wsendctlmesg(Window*, int, Rectangle, void*);
 void		wsetcursor(Window*, int);
 void		wsetname(Window*);
 void		wsetorigin(Window*, uint, int);
diff --git a/sys/src/cmd/rio/rio.c b/sys/src/cmd/rio/rio.c
index 119117c93..8dbbf47be 100644
--- a/sys/src/cmd/rio/rio.c
+++ b/sys/src/cmd/rio/rio.c
@@ -345,7 +345,7 @@ keyboardthread(void*)
 	while(s = recvp(kbdchan)){
 		if(*s == 'k' || *s == 'K')
 			shiftdown = utfrune(s+1, Kshift) != nil;
-		if(input == nil || input->deleted || sendp(input->ck, s) <= 0)
+		if(input == nil || sendp(input->ck, s) <= 0)
 			free(s);
 	}
 }
@@ -1113,10 +1113,8 @@ resize(void)
 		return;
 	incref(w);
 	i = sweep();
-	if(i){
+	if(i)
 		wsendctlmesg(w, Reshaped, i->r, i);
-		wcurrent(w);
-	}
 	wclose(w);
 }
 
@@ -1132,10 +1130,8 @@ move(void)
 		return;
 	incref(w);
 	i = drag(w, &r);
-	if(i){
+	if(i)
 		wsendctlmesg(w, Moved, r, i);
-		wcurrent(w);
-	}
 	cornercursor(w, mouse->xy, 1);
 	wclose(w);
 }
@@ -1154,8 +1150,6 @@ whide(Window *w)
 	incref(w);
 	i = allocimage(display, w->screenr, w->i->chan, 0, DNofill);
 	if(i){
-		if(w == input)
-			input = nil;
 		hidden[nhidden++] = w;
 		wsendctlmesg(w, Reshaped, ZR, i);
 	}
@@ -1180,7 +1174,6 @@ wunhide(Window *w)
 		--nhidden;
 		memmove(hidden+j, hidden+j+1, (nhidden-j)*sizeof(Window*));
 		wsendctlmesg(w, Reshaped, w->i->r, i);
-		wcurrent(w);
 	}
 	wclose(w);
 	return i!=0;
@@ -1257,7 +1250,6 @@ new(Image *i, int hideit, int scrollit, int pid, char *dir, char *cmd, char **ar
 	threadcreate(winctl, w, 8192);
 	if(!hideit)
 		wcurrent(w);
-	flushimage(display, 1);
 	if(pid == 0){
 		arg = emalloc(5*sizeof(void*));
 		arg[0] = w;
diff --git a/sys/src/cmd/rio/wctl.c b/sys/src/cmd/rio/wctl.c
index efe6949ff..9d1cf796e 100644
--- a/sys/src/cmd/rio/wctl.c
+++ b/sys/src/cmd/rio/wctl.c
@@ -388,6 +388,7 @@ wctlcmd(Window *w, Rectangle r, int cmd, char *err)
 		wbottomme(w);
 		return 1;
 	case Current:
+		wtopme(w);
 		wcurrent(w);
 		return 1;
 	case Hide:
diff --git a/sys/src/cmd/rio/wind.c b/sys/src/cmd/rio/wind.c
index 313247576..fab34f95a 100644
--- a/sys/src/cmd/rio/wind.c
+++ b/sys/src/cmd/rio/wind.c
@@ -113,10 +113,7 @@ wresize(Window *w, Image *i, int move)
 		wsetselect(w, w->q0, w->q1);
 		wscrdraw(w);
 	}
-	if(w == input)
-		wborder(w, Selborder);
-	else
-		wborder(w, Unselborder);
+	wborder(w, Selborder);
 	wsetname(w);
 	w->topped = ++topped;
 	w->resized = TRUE;
@@ -312,7 +309,7 @@ winctl(void *arg)
 			send(mrm.cm, &m.Mouse);
 			continue;
 		case WCtl:
-			if(wctlmesg(w, wcm.type, wcm.r, wcm.image) == Exited){
+			if(wctlmesg(w, wcm.type, wcm.r, wcm.p) == Exited){
 				for(i=0; i<nelem(kbdq); i++)
 					free(kbdq[i]);
 				chanfree(crm.c1);
@@ -1058,26 +1055,29 @@ wselect(Window *w)
 }
 
 void
-wsendctlmesg(Window *w, int type, Rectangle r, Image *image)
+wsendctlmesg(Window *w, int type, Rectangle r, void *p)
 {
 	Wctlmesg wcm;
 
 	wcm.type = type;
 	wcm.r = r;
-	wcm.image = image;
+	wcm.p = p;
 	send(w->cctl, &wcm);
 }
 
 int
-wctlmesg(Window *w, int m, Rectangle r, Image *i)
+wctlmesg(Window *w, int m, Rectangle r, void *p)
 {
 	char buf[64];
+	Image *i = p;
 
 	switch(m){
 	default:
 		error("unknown control message");
 		break;
 	case Wakeup:
+		if(p!=nil)
+			sendp((Channel*)p, w);
 		break;
 	case Moved:
 	case Reshaped:
@@ -1090,6 +1090,55 @@ wctlmesg(Window *w, int m, Rectangle r, Image *i)
 		wresize(w, i, m==Moved);
 		proccreate(deletetimeoutproc, estrdup(buf), 4096);
 		flushimage(display, 1);
+		if(Dx(r)<=0){	/* window got hidden, if we had the input, drop it */
+			if(w==input)
+				input = nil;
+			break;
+		}
+		/* fall through to get input if needed */
+	case Topped:
+		if(w->deleted || w==input)
+			break;
+		if(input!=nil){
+			Window *oi;
+			Channel *c;
+	
+			oi = input;
+			incref(oi);
+
+			/*
+			 * have to wait until old input responds before
+			 * changing input to us because the window might
+			 * currently be mouse tracking and it is not
+			 * prepared for getting its input revoked.
+			 */
+			c = chancreate(sizeof(void*), 0);
+			wsendctlmesg(oi, Wakeup, ZR, c);
+			recv(c, nil);
+			chanfree(c);
+
+			/*
+			 * if we are still top window and nobody else has taken
+			 * input from original window, take the input.
+			 */
+			if(!w->deleted && w->topped==topped && oi==input){
+				input = w;
+
+				oi->wctlready = 1;
+				wsendctlmesg(oi, Repaint, ZR, nil);
+			}
+			wclose(oi);
+		} else
+			input = w;
+		w->wctlready = 1;
+		if(m!=Topped && w==input)
+			break;
+		/* fall thrugh for redraw after input change */
+	case Repaint:
+		if(w->deleted || Dx(w->screenr)<=0)
+			break;
+		wrepaint(w);
+		flushimage(display, 1);
 		break;
 	case Refresh:
 		if(w->deleted || Dx(w->screenr)<=0 || !rectclip(&r, w->i->r) || w->mouseopen)
@@ -1114,12 +1163,10 @@ wctlmesg(Window *w, int m, Rectangle r, Image *i)
 		break;
 	case Holdon:
 	case Holdoff:
-		if(w == input)
-			wsetcursor(w, 0);
-		/* no break */
-	case Repaint:
 		if(w->deleted)
 			break;
+		if(w==input)
+			wsetcursor(w, 0);
 		wrepaint(w);
 		flushimage(display, 1);
 		break;
@@ -1206,22 +1253,8 @@ wpointto(Point pt)
 void
 wcurrent(Window *w)
 {
-	Window *oi;
-
-	if(wkeyboard!=nil && w==wkeyboard)
-		return;
-	oi = input;
-	input = w;
-	if(w != oi){
-		if(oi){
-			oi->wctlready = 1;
-			wsendctlmesg(oi, Repaint, ZR, nil);
-		}
-		if(w){
-			w->wctlready = 1;
-			wsendctlmesg(w, Repaint, ZR, nil);
-		}
-	}
+	if(w!=nil && w!=input)
+		wsendctlmesg(w, Topped, ZR, nil);
 }
 
 void
diff --git a/sys/src/cmd/rio/xfid.c b/sys/src/cmd/rio/xfid.c
index 9359bc12c..a0da0c5fd 100644
--- a/sys/src/cmd/rio/xfid.c
+++ b/sys/src/cmd/rio/xfid.c
@@ -190,7 +190,6 @@ xfidattach(Xfid *x)
 				if(pid == 0)
 					pid = -1;	/* make sure we don't pop a shell! - UGH */
 				w = new(i, hideit, scrollit, pid, nil, nil, nil);
-				flushimage(display, 1);
 				newlymade = TRUE;
 			}else
 				err = Ewindow;
@@ -550,7 +549,6 @@ xfidwrite(Xfid *x)
 			filsysrespond(x->fs, x, &fc, buf);
 			return;
 		}
-		flushimage(display, 1);
 		break;
 
 	default: