improve server handling of errors now that Decoder grabs full message.

R=rsc
DELTA=23  (4 added, 7 deleted, 12 changed)
OCL=31701
CL=31703

src/pkg/rpc/client.go

@@ -66,7 +66,7 @@ func (client *Client) send(c *Call) {
 	client.sending.Unlock();
 }
 
-func (client *Client) serve() {
+func (client *Client) input() {
 	var err os.Error;
 	for err == nil {
 		response := new(Response);
@@ -107,7 +107,7 @@ func NewClient(conn io.ReadWriteCloser) *Client {
 	client.enc = gob.NewEncoder(conn);
 	client.dec = gob.NewDecoder(conn);
 	client.pending = make(map[uint64] *Call);
-	go client.serve();
+	go client.input();
 	return client;
 }
 

src/pkg/rpc/server.go

@@ -14,7 +14,6 @@ import (
 	"reflect";
 	"strings";
 	"sync";
-	"time";	// See TODO in serve()
 	"unicode";
 	"utf8";
 )
@@ -174,7 +173,7 @@ func (s *service) call(sending *sync.Mutex, function *reflect.FuncValue, req *Re
 	sendResponse(sending, req, replyv.Interface(), enc, errmsg);
 }
 
-func (server *serverType) serve(conn io.ReadWriteCloser) {
+func (server *serverType) input(conn io.ReadWriteCloser) {
 	dec := gob.NewDecoder(conn);
 	enc := gob.NewEncoder(conn);
 	sending := new(sync.Mutex);
@@ -183,28 +182,32 @@ func (server *serverType) serve(conn io.ReadWriteCloser) {
 		req := new(Request);
 		err := dec.Decode(req);
 		if err != nil {
+			if err == os.EOF || err == io.ErrUnexpectedEOF {
+				log.Stderr("rpc: ", err);
+				break;
+			}
 			s := "rpc: server cannot decode request: " + err.String();
 			sendResponse(sending, req, invalidRequest, enc, s);
-			break;
+			continue;
 		}
 		serviceMethod := strings.Split(req.ServiceMethod, ".", 0);
 		if len(serviceMethod) != 2 {
 			s := "rpc: service/method request ill:formed: " + req.ServiceMethod;
 			sendResponse(sending, req, invalidRequest, enc, s);
-			break;
+			continue;
 		}
 		// Look up the request.
 		service, ok := server.serviceMap[serviceMethod[0]];
 		if !ok {
 			s := "rpc: can't find service " + req.ServiceMethod;
 			sendResponse(sending, req, invalidRequest, enc, s);
-			break;
+			continue;
 		}
 		mtype, ok := service.method[serviceMethod[1]];
 		if !ok {
 			s := "rpc: can't find method " + req.ServiceMethod;
 			sendResponse(sending, req, invalidRequest, enc, s);
-			break;
+			continue;
 		}
 		method := mtype.method;
 		// Decode the argument value.
@@ -212,18 +215,12 @@ func (server *serverType) serve(conn io.ReadWriteCloser) {
 		replyv := _new(mtype.replyType);
 		err = dec.Decode(argv.Interface());
 		if err != nil {
-			log.Stderr("tearing down connection:", err);
+			log.Stderr("rpc: tearing down", serviceMethod[0], "connection:", err);
 			sendResponse(sending, req, replyv.Interface(), enc, err.String());
-			break;
+			continue;
 		}
 		go service.call(sending, method.Func, req, argv, replyv, enc);
 	}
-	// TODO(r):  Gobs cannot handle unexpected data yet.  Once they can, we can
-	// ignore it and the connection can persist.  For now, though, bad data
-	// ruins the connection and we must shut down.  The sleep is necessary to
-	// guarantee all the data gets out before we close the connection, so the
-	// client can see the error description.
-	time.Sleep(2e9);
 	conn.Close();
 }
 
@@ -233,7 +230,7 @@ func (server *serverType) accept(lis net.Listener) {
 		if err != nil {
 			log.Exit("rpc.Serve: accept:", err.String());	// TODO(r): exit?
 		}
-		go server.serve(conn);
+		go server.input(conn);
 	}
 }
 
@@ -250,7 +247,7 @@ func Add(rcvr interface{}) os.Error {
 // ServeConn runs the server on a single connection.  When the connection
 // completes, service terminates.
 func ServeConn(conn io.ReadWriteCloser) {
-	go server.serve(conn)
+	go server.input(conn)
 }
 
 // Accept accepts connections on the listener and serves requests
@@ -276,7 +273,7 @@ func serveHTTP(c *http.Conn, req *http.Request) {
 		return;
 	}
 	io.WriteString(conn, "HTTP/1.0 " + connected + "\n\n");
-	server.serve(conn);
+	server.input(conn);
 }
 
 // HandleHTTP registers an HTTP handler for RPC messages.