add Close() and Closed() to ChanValue

R=r
DELTA=60  (56 added, 3 deleted, 1 changed)
OCL=33868
CL=33872

src/pkg/reflect/all_test.go

@@ -726,6 +726,25 @@ func TestChan(t *testing.T) {
 				t.Errorf("TrySend 6, recv %d", i);
 			}
 		}
+
+		// Close
+		c <- 123;
+		cv.Close();
+		if cv.Closed() {
+			t.Errorf("closed too soon - 1");
+		}
+		if i := cv.Recv().(*IntValue).Get(); i != 123 {
+			t.Errorf("send 123 then close; Recv %d", i);
+		}
+		if cv.Closed() {
+			t.Errorf("closed too soon - 2");
+		}
+		if i := cv.Recv().(*IntValue).Get(); i != 0 {
+			t.Errorf("after close Recv %d", i);
+		}
+		if !cv.Closed() {
+			t.Errorf("not closed");
+		}
 	}
 
 	// check creation of unbuffered channel

src/pkg/reflect/value.go

@@ -634,6 +634,20 @@ func (v *ChanValue) Get() uintptr {
 func makechan(typ *runtime.ChanType, size uint32) (ch *byte)
 func chansend(ch, val *byte, pres *bool)
 func chanrecv(ch, val *byte, pres *bool)
+func chanclosed(ch *byte) bool
+func chanclose(ch *byte)
+
+// Closed returns the result of closed(c) on the underlying channel.
+func (v *ChanValue) Closed() bool {
+	ch := *(**byte)(v.addr);
+	return chanclosed(ch);
+}
+
+// Close closes the channel.
+func (v *ChanValue) Close() {
+	ch := *(**byte)(v.addr);
+	chanclose(ch);
+}
 
 // internal send; non-blocking if b != nil
 func (v *ChanValue) send(x Value, b *bool) {

src/pkg/runtime/chan.c

@@ -905,14 +905,24 @@ sys·closechan(Hchan *c)
 	unlock(&chanlock);
 }
 
+void
+chanclose(Hchan *c)
+{
+	sys·closechan(c);
+}
+
+bool
+chanclosed(Hchan *c)
+{
+	return (c->closed & Rclosed) != 0;
+}
+
+
 // closedchan(sel *byte) bool;
 void
 sys·closedchan(Hchan *c, bool closed)
 {
-	// test Rclosed
-	closed = 0;
-	if(c->closed & Rclosed)
-		closed = 1;
+	closed = chanclosed(c);
 	FLUSH(&closed);
 }
 

src/pkg/runtime/reflect.cgo

@@ -78,6 +78,14 @@ func chanrecv(ch *byte, val *byte, pres *bool) {
 	chanrecv((Hchan*)ch, val, pres);
 }
 
+func chanclose(ch *byte) {
+	chanclose((Hchan*)ch);
+}
+
+func chanclosed(ch *byte) (r bool) {
+	r = chanclosed((Hchan*)ch);
+}
+
 
 /*
  * Go wrappers around the functions in iface.c

src/pkg/runtime/runtime.h

@@ -73,7 +73,7 @@ typedef	struct	Hchan		Hchan;
  * amd64: allocated downwards from R15
  * x86: allocated upwards from 0(FS)
  * arm: allocated upwards from R9
- * 
+ *
  * every C file linked into a Go program must include runtime.h
  * so that the C compiler knows to avoid other uses of these registers.
  * the Go compilers know to avoid them.
@@ -491,5 +491,7 @@ Hmap*	makemap(uint32, uint32, uint32, uint32, uint32);
 Hchan*	makechan(uint32, uint32, uint32);
 void	chansend(Hchan*, void*, bool*);
 void	chanrecv(Hchan*, void*, bool*);
+void	chanclose(Hchan*);
+bool	chanclosed(Hchan*);
 
 void	ifaceE2I(struct InterfaceType*, Eface, Iface*);