runtime: always set *received in chanrecv.

Also fix comment.

The only caller of chanrecv initializes the value to false, so
this patch makes no difference at present.  But it seems like
the right thing to do.

R=rsc
CC=golang-dev
https://golang.org/cl/4312053

diff --git a/src/pkg/runtime/chan.c b/src/pkg/runtime/chan.c
index 9630c436f6831ad5c6da6fbc051a64575a36e570..abb1b690ddbe5928f8b5b88665e347c269fd1439 100644 (file)
--- a/src/pkg/runtime/chan.c
+++ b/src/pkg/runtime/chan.c
@@ -366,6 +366,8 @@ asynch:
                if(selected != nil) {
                        runtime·unlock(c);
                        *selected = false;
+                       if(received != nil)
+                               *received = false;
                        return;
                }
                sg = allocsg(c);
@@ -521,7 +523,7 @@ runtime·selectnbrecv(byte *v, Hchan *c, bool selected)
 // compiler implements
 //
 //     select {
-//     case v = <-c:
+//     case v, ok = <-c:
 //             ... foo
 //     default:
 //             ... bar
@@ -529,7 +531,7 @@ runtime·selectnbrecv(byte *v, Hchan *c, bool selected)
 //
 // as
 //
-//     if c != nil && selectnbrecv(&v, c) {
+//     if c != nil && selectnbrecv2(&v, &ok, c) {
 //             ... foo
 //     } else {
 //             ... bar