Update to current version of Go library (revision 94d654be2064).

From-SVN: r171076

6 files changed, 164 insertions, 139 deletions

diff --git a/libgo/go/rpc/client.go b/libgo/go/rpc/client.go
index 601c497..6de6d13 100644
--- a/libgo/go/rpc/client.go
+++ b/libgo/go/rpc/client.go
@@ -15,6 +15,16 @@ import (
 	"sync"
 )
 
+// ServerError represents an error that has been returned from
+// the remote side of the RPC connection.
+type ServerError string
+
+func (e ServerError) String() string {
+	return string(e)
+}
+
+const ErrShutdown = os.ErrorString("connection is shut down")
+
 // Call represents an active RPC.
 type Call struct {
 	ServiceMethod string      // The name of the service and method to call.
@@ -30,12 +40,12 @@ type Call struct {
 // with a single Client.
 type Client struct {
 	mutex    sync.Mutex // protects pending, seq
-	shutdown os.Error   // non-nil if the client is shut down
 	sending  sync.Mutex
 	seq      uint64
 	codec    ClientCodec
 	pending  map[uint64]*Call
 	closing  bool
+	shutdown bool
 }
 
 // A ClientCodec implements writing of RPC requests and
@@ -43,7 +53,9 @@ type Client struct {
 // The client calls WriteRequest to write a request to the connection
 // and calls ReadResponseHeader and ReadResponseBody in pairs
 // to read responses.  The client calls Close when finished with the
-// connection.
+// connection. ReadResponseBody may be called with a nil
+// argument to force the body of the response to be read and then
+// discarded.
 type ClientCodec interface {
 	WriteRequest(*Request, interface{}) os.Error
 	ReadResponseHeader(*Response) os.Error
@@ -55,10 +67,10 @@ type ClientCodec interface {
 func (client *Client) send(c *Call) {
 	// Register this call.
 	client.mutex.Lock()
-	if client.shutdown != nil {
-		c.Error = client.shutdown
+	if client.shutdown {
+		c.Error = ErrShutdown
 		client.mutex.Unlock()
-		_ = c.Done <- c // do not block
+		c.done()
 		return
 	}
 	c.seq = client.seq
@@ -93,25 +105,30 @@ func (client *Client) input() {
 		c := client.pending[seq]
 		client.pending[seq] = c, false
 		client.mutex.Unlock()
-		err = client.codec.ReadResponseBody(c.Reply)
-		if response.Error != "" {
-			c.Error = os.ErrorString(response.Error)
-		} else if err != nil {
-			c.Error = err
+
+		if response.Error == "" {
+			err = client.codec.ReadResponseBody(c.Reply)
+			if err != nil {
+				c.Error = os.ErrorString("reading body " + err.String())
+			}
 		} else {
-			// Empty strings should turn into nil os.Errors
-			c.Error = nil
+			// We've got an error response. Give this to the request;
+			// any subsequent requests will get the ReadResponseBody
+			// error if there is one.
+			c.Error = ServerError(response.Error)
+			err = client.codec.ReadResponseBody(nil)
+			if err != nil {
+				err = os.ErrorString("reading error body: " + err.String())
+			}
 		}
-		// We don't want to block here.  It is the caller's responsibility to make
-		// sure the channel has enough buffer space. See comment in Go().
-		_ = c.Done <- c // do not block
+		c.done()
 	}
 	// Terminate pending calls.
 	client.mutex.Lock()
-	client.shutdown = err
+	client.shutdown = true
 	for _, call := range client.pending {
 		call.Error = err
-		_ = call.Done <- call // do not block
+		call.done()
 	}
 	client.mutex.Unlock()
 	if err != os.EOF || !client.closing {
@@ -119,6 +136,16 @@ func (client *Client) input() {
 	}
 }
 
+func (call *Call) done() {
+	select {
+	case call.Done <- call:
+		// ok
+	default:
+		// We don't want to block here.  It is the caller's responsibility to make
+		// sure the channel has enough buffer space. See comment in Go().
+	}
+}
+
 // NewClient returns a new Client to handle requests to the
 // set of services at the other end of the connection.
 func NewClient(conn io.ReadWriteCloser) *Client {
@@ -201,10 +228,11 @@ func Dial(network, address string) (*Client, os.Error) {
 }
 
 func (client *Client) Close() os.Error {
-	if client.shutdown != nil || client.closing {
-		return os.ErrorString("rpc: already closed")
-	}
 	client.mutex.Lock()
+	if client.shutdown || client.closing {
+		client.mutex.Unlock()
+		return ErrShutdown
+	}
 	client.closing = true
 	client.mutex.Unlock()
 	return client.codec.Close()
@@ -231,9 +259,9 @@ func (client *Client) Go(serviceMethod string, args interface{}, reply interface
 		}
 	}
 	c.Done = done
-	if client.shutdown != nil {
-		c.Error = client.shutdown
-		_ = c.Done <- c // do not block
+	if client.shutdown {
+		c.Error = ErrShutdown
+		c.done()
 		return c
 	}
 	client.send(c)
@@ -242,8 +270,8 @@ func (client *Client) Go(serviceMethod string, args interface{}, reply interface
 
 // Call invokes the named function, waits for it to complete, and returns its error status.
 func (client *Client) Call(serviceMethod string, args interface{}, reply interface{}) os.Error {
-	if client.shutdown != nil {
-		return client.shutdown
+	if client.shutdown {
+		return ErrShutdown
 	}
 	call := <-client.Go(serviceMethod, args, reply, nil).Done
 	return call.Error
diff --git a/libgo/go/rpc/debug.go b/libgo/go/rpc/debug.go
index 44b32e0..32dc8a1 100644
--- a/libgo/go/rpc/debug.go
+++ b/libgo/go/rpc/debug.go
@@ -83,7 +83,7 @@ func (server debugHTTP) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	}
 	server.Unlock()
 	sort.Sort(services)
-	err := debug.Execute(services, w)
+	err := debug.Execute(w, services)
 	if err != nil {
 		fmt.Fprintln(w, "rpc: error executing template:", err.String())
 	}
diff --git a/libgo/go/rpc/jsonrpc/client.go b/libgo/go/rpc/jsonrpc/client.go
index dcaa69f..5b806bd 100644
--- a/libgo/go/rpc/jsonrpc/client.go
+++ b/libgo/go/rpc/jsonrpc/client.go
@@ -98,6 +98,9 @@ func (c *clientCodec) ReadResponseHeader(r *rpc.Response) os.Error {
 }
 
 func (c *clientCodec) ReadResponseBody(x interface{}) os.Error {
+	if x == nil {
+		return nil
+	}
 	return json.Unmarshal(*c.resp.Result, x)
 }
 
diff --git a/libgo/go/rpc/jsonrpc/server.go b/libgo/go/rpc/jsonrpc/server.go
index bf53bda..9c6b8b4 100644
--- a/libgo/go/rpc/jsonrpc/server.go
+++ b/libgo/go/rpc/jsonrpc/server.go
@@ -85,6 +85,9 @@ func (c *serverCodec) ReadRequestHeader(r *rpc.Request) os.Error {
 }
 
 func (c *serverCodec) ReadRequestBody(x interface{}) os.Error {
+	if x == nil {
+		return nil
+	}
 	// JSON params is array value.
 	// RPC params is struct.
 	// Unmarshal into array containing struct for now.
diff --git a/libgo/go/rpc/server.go b/libgo/go/rpc/server.go
index 5c50bcc..9dcda41 100644
--- a/libgo/go/rpc/server.go
+++ b/libgo/go/rpc/server.go
@@ -73,7 +73,7 @@
 		rpc.HandleHTTP()
 		l, e := net.Listen("tcp", ":1234")
 		if e != nil {
-			log.Exit("listen error:", e)
+			log.Fatal("listen error:", e)
 		}
 		go http.Serve(l, nil)
 
@@ -82,7 +82,7 @@
 
 		client, err := rpc.DialHTTP("tcp", serverAddress + ":1234")
 		if err != nil {
-			log.Exit("dialing:", err)
+			log.Fatal("dialing:", err)
 		}
 
 	Then it can make a remote call:
@@ -92,7 +92,7 @@
 		var reply int
 		err = client.Call("Arith.Multiply", args, &reply)
 		if err != nil {
-			log.Exit("arith error:", err)
+			log.Fatal("arith error:", err)
 		}
 		fmt.Printf("Arith: %d*%d=%d", args.A, args.B, *reply)
 
@@ -225,7 +225,7 @@ func (server *Server) register(rcvr interface{}, name string, useName bool) os.E
 		sname = name
 	}
 	if sname == "" {
-		log.Exit("rpc: no service name for type", s.typ.String())
+		log.Fatal("rpc: no service name for type", s.typ.String())
 	}
 	if s.typ.PkgPath() != "" && !isExported(sname) && !useName {
 		s := "rpc Register: type " + sname + " is not exported"
@@ -299,10 +299,10 @@ func (server *Server) register(rcvr interface{}, name string, useName bool) os.E
 
 // A value sent as a placeholder for the response when the server receives an invalid request.
 type InvalidRequest struct {
-	marker int
+	Marker int
 }
 
-var invalidRequest = InvalidRequest{1}
+var invalidRequest = InvalidRequest{}
 
 func _new(t *reflect.PtrType) *reflect.PtrValue {
 	v := reflect.MakeZero(t).(*reflect.PtrValue)
@@ -316,6 +316,7 @@ func sendResponse(sending *sync.Mutex, req *Request, reply interface{}, codec Se
 	resp.ServiceMethod = req.ServiceMethod
 	if errmsg != "" {
 		resp.Error = errmsg
+		reply = invalidRequest
 	}
 	resp.Seq = req.Seq
 	sending.Lock()
@@ -389,54 +390,74 @@ func (server *Server) ServeConn(conn io.ReadWriteCloser) {
 func (server *Server) ServeCodec(codec ServerCodec) {
 	sending := new(sync.Mutex)
 	for {
-		// Grab the request header.
-		req := new(Request)
-		err := codec.ReadRequestHeader(req)
+		req, service, mtype, err := server.readRequest(codec)
 		if err != nil {
+			if err != os.EOF {
+				log.Println("rpc:", err)
+			}
 			if err == os.EOF || err == io.ErrUnexpectedEOF {
-				if err == io.ErrUnexpectedEOF {
-					log.Println("rpc:", err)
-				}
 				break
 			}
-			s := "rpc: server cannot decode request: " + err.String()
-			sendResponse(sending, req, invalidRequest, codec, s)
-			break
-		}
-		serviceMethod := strings.Split(req.ServiceMethod, ".", -1)
-		if len(serviceMethod) != 2 {
-			s := "rpc: service/method request ill-formed: " + req.ServiceMethod
-			sendResponse(sending, req, invalidRequest, codec, s)
-			continue
-		}
-		// Look up the request.
-		server.Lock()
-		service, ok := server.serviceMap[serviceMethod[0]]
-		server.Unlock()
-		if !ok {
-			s := "rpc: can't find service " + req.ServiceMethod
-			sendResponse(sending, req, invalidRequest, codec, s)
-			continue
-		}
-		mtype, ok := service.method[serviceMethod[1]]
-		if !ok {
-			s := "rpc: can't find method " + req.ServiceMethod
-			sendResponse(sending, req, invalidRequest, codec, s)
+			// discard body
+			codec.ReadRequestBody(nil)
+
+			// send a response if we actually managed to read a header.
+			if req != nil {
+				sendResponse(sending, req, invalidRequest, codec, err.String())
+			}
 			continue
 		}
+
 		// Decode the argument value.
 		argv := _new(mtype.ArgType)
 		replyv := _new(mtype.ReplyType)
 		err = codec.ReadRequestBody(argv.Interface())
 		if err != nil {
-			log.Println("rpc: tearing down", serviceMethod[0], "connection:", err)
+			if err == os.EOF || err == io.ErrUnexpectedEOF {
+				if err == io.ErrUnexpectedEOF {
+					log.Println("rpc:", err)
+				}
+				break
+			}
 			sendResponse(sending, req, replyv.Interface(), codec, err.String())
-			break
+			continue
 		}
 		go service.call(sending, mtype, req, argv, replyv, codec)
 	}
 	codec.Close()
 }
+func (server *Server) readRequest(codec ServerCodec) (req *Request, service *service, mtype *methodType, err os.Error) {
+	// Grab the request header.
+	req = new(Request)
+	err = codec.ReadRequestHeader(req)
+	if err != nil {
+		req = nil
+		if err == os.EOF || err == io.ErrUnexpectedEOF {
+			return
+		}
+		err = os.ErrorString("rpc: server cannot decode request: " + err.String())
+		return
+	}
+
+	serviceMethod := strings.Split(req.ServiceMethod, ".", -1)
+	if len(serviceMethod) != 2 {
+		err = os.ErrorString("rpc: service/method request ill-formed: " + req.ServiceMethod)
+		return
+	}
+	// Look up the request.
+	server.Lock()
+	service = server.serviceMap[serviceMethod[0]]
+	server.Unlock()
+	if service == nil {
+		err = os.ErrorString("rpc: can't find service " + req.ServiceMethod)
+		return
+	}
+	mtype = service.method[serviceMethod[1]]
+	if mtype == nil {
+		err = os.ErrorString("rpc: can't find method " + req.ServiceMethod)
+	}
+	return
+}
 
 // Accept accepts connections on the listener and serves requests
 // for each incoming connection.  Accept blocks; the caller typically
@@ -445,7 +466,7 @@ func (server *Server) Accept(lis net.Listener) {
 	for {
 		conn, err := lis.Accept()
 		if err != nil {
-			log.Exit("rpc.Serve: accept:", err.String()) // TODO(r): exit?
+			log.Fatal("rpc.Serve: accept:", err.String()) // TODO(r): exit?
 		}
 		go server.ServeConn(conn)
 	}
@@ -465,7 +486,8 @@ func RegisterName(name string, rcvr interface{}) os.Error {
 // The server calls ReadRequestHeader and ReadRequestBody in pairs
 // to read requests from the connection, and it calls WriteResponse to
 // write a response back.  The server calls Close when finished with the
-// connection.
+// connection. ReadRequestBody may be called with a nil
+// argument to force the body of the request to be read and discarded.
 type ServerCodec interface {
 	ReadRequestHeader(*Request) os.Error
 	ReadRequestBody(interface{}) os.Error
diff --git a/libgo/go/rpc/server_test.go b/libgo/go/rpc/server_test.go
index 355d51c..05aaebc 100644
--- a/libgo/go/rpc/server_test.go
+++ b/libgo/go/rpc/server_test.go
@@ -72,7 +72,7 @@ func (t *Arith) Error(args *Args, reply *Reply) os.Error {
 func listenTCP() (net.Listener, string) {
 	l, e := net.Listen("tcp", "127.0.0.1:0") // any available address
 	if e != nil {
-		log.Exitf("net.Listen tcp :0: %v", e)
+		log.Fatalf("net.Listen tcp :0: %v", e)
 	}
 	return l, l.Addr().String()
 }
@@ -134,14 +134,25 @@ func testRPC(t *testing.T, addr string) {
 		t.Errorf("Add: expected %d got %d", reply.C, args.A+args.B)
 	}
 
-	args = &Args{7, 8}
+	// Nonexistent method
+	args = &Args{7, 0}
 	reply = new(Reply)
-	err = client.Call("Arith.Mul", args, reply)
-	if err != nil {
-		t.Errorf("Mul: expected no error but got string %q", err.String())
+	err = client.Call("Arith.BadOperation", args, reply)
+	// expect an error
+	if err == nil {
+		t.Error("BadOperation: expected error")
+	} else if !strings.HasPrefix(err.String(), "rpc: can't find method ") {
+		t.Errorf("BadOperation: expected can't find method error; got %q", err)
 	}
-	if reply.C != args.A*args.B {
-		t.Errorf("Mul: expected %d got %d", reply.C, args.A*args.B)
+
+	// Unknown service
+	args = &Args{7, 8}
+	reply = new(Reply)
+	err = client.Call("Arith.Unknown", args, reply)
+	if err == nil {
+		t.Error("expected error calling unknown service")
+	} else if strings.Index(err.String(), "method") < 0 {
+		t.Error("expected error about method; got", err)
 	}
 
 	// Out of order.
@@ -178,6 +189,15 @@ func testRPC(t *testing.T, addr string) {
 		t.Error("Div: expected divide by zero error; got", err)
 	}
 
+	// Bad type.
+	reply = new(Reply)
+	err = client.Call("Arith.Add", reply, reply) // args, reply would be the correct thing to use
+	if err == nil {
+		t.Error("expected error calling Arith.Add with wrong arg type")
+	} else if strings.Index(err.String(), "type") < 0 {
+		t.Error("expected error about type; got", err)
+	}
+
 	// Non-struct argument
 	const Val = 12345
 	str := fmt.Sprint(Val)
@@ -200,9 +220,19 @@ func testRPC(t *testing.T, addr string) {
 	if str != expect {
 		t.Errorf("String: expected %s got %s", expect, str)
 	}
+
+	args = &Args{7, 8}
+	reply = new(Reply)
+	err = client.Call("Arith.Mul", args, reply)
+	if err != nil {
+		t.Errorf("Mul: expected no error but got string %q", err.String())
+	}
+	if reply.C != args.A*args.B {
+		t.Errorf("Mul: expected %d got %d", reply.C, args.A*args.B)
+	}
 }
 
-func TestHTTPRPC(t *testing.T) {
+func TestHTTP(t *testing.T) {
 	once.Do(startServer)
 	testHTTPRPC(t, "")
 	newOnce.Do(startNewServer)
@@ -233,65 +263,6 @@ func testHTTPRPC(t *testing.T, path string) {
 	}
 }
 
-func TestCheckUnknownService(t *testing.T) {
-	once.Do(startServer)
-
-	conn, err := net.Dial("tcp", "", serverAddr)
-	if err != nil {
-		t.Fatal("dialing:", err)
-	}
-
-	client := NewClient(conn)
-
-	args := &Args{7, 8}
-	reply := new(Reply)
-	err = client.Call("Unknown.Add", args, reply)
-	if err == nil {
-		t.Error("expected error calling unknown service")
-	} else if strings.Index(err.String(), "service") < 0 {
-		t.Error("expected error about service; got", err)
-	}
-}
-
-func TestCheckUnknownMethod(t *testing.T) {
-	once.Do(startServer)
-
-	conn, err := net.Dial("tcp", "", serverAddr)
-	if err != nil {
-		t.Fatal("dialing:", err)
-	}
-
-	client := NewClient(conn)
-
-	args := &Args{7, 8}
-	reply := new(Reply)
-	err = client.Call("Arith.Unknown", args, reply)
-	if err == nil {
-		t.Error("expected error calling unknown service")
-	} else if strings.Index(err.String(), "method") < 0 {
-		t.Error("expected error about method; got", err)
-	}
-}
-
-func TestCheckBadType(t *testing.T) {
-	once.Do(startServer)
-
-	conn, err := net.Dial("tcp", "", serverAddr)
-	if err != nil {
-		t.Fatal("dialing:", err)
-	}
-
-	client := NewClient(conn)
-
-	reply := new(Reply)
-	err = client.Call("Arith.Add", reply, reply) // args, reply would be the correct thing to use
-	if err == nil {
-		t.Error("expected error calling Arith.Add with wrong arg type")
-	} else if strings.Index(err.String(), "type") < 0 {
-		t.Error("expected error about type; got", err)
-	}
-}
-
 type ArgNotPointer int
 type ReplyNotPointer int
 type ArgNotPublic int
@@ -364,14 +335,12 @@ func TestSendDeadlock(t *testing.T) {
 		testSendDeadlock(client)
 		done <- true
 	}()
-	for i := 0; i < 50; i++ {
-		time.Sleep(100 * 1e6)
-		_, ok := <-done
-		if ok {
-			return
-		}
+	select {
+	case <-done:
+		return
+	case <-time.After(5e9):
+		t.Fatal("deadlock")
 	}
-	t.Fatal("deadlock")
 }
 
 func testSendDeadlock(client *Client) {