libgo: update to Go 1.11

    
    Reviewed-on: https://go-review.googlesource.com/136435

gotools/:
	* Makefile.am (mostlyclean-local): Run chmod on check-go-dir to
	make sure it is writable.
	(check-go-tools): Likewise.
	(check-vet): Copy internal/objabi to check-vet-dir.
	* Makefile.in: Rebuild.

From-SVN: r264546

2 files changed, 11 insertions, 3 deletions

diff --git a/libgo/go/net/rpc/client.go b/libgo/go/net/rpc/client.go
index fce6a48..cad2d45 100644
--- a/libgo/go/net/rpc/client.go
+++ b/libgo/go/net/rpc/client.go
@@ -59,8 +59,8 @@ type Client struct {
 // connection. ReadResponseBody may be called with a nil
 // argument to force the body of the response to be read and then
 // discarded.
+// See NewClient's comment for information about concurrent access.
 type ClientCodec interface {
-	// WriteRequest must be safe for concurrent use by multiple goroutines.
 	WriteRequest(*Request, interface{}) error
 	ReadResponseHeader(*Response) error
 	ReadResponseBody(interface{}) error
@@ -75,8 +75,8 @@ func (client *Client) send(call *Call) {
 	// Register this call.
 	client.mutex.Lock()
 	if client.shutdown || client.closing {
-		call.Error = ErrShutdown
 		client.mutex.Unlock()
+		call.Error = ErrShutdown
 		call.done()
 		return
 	}
@@ -185,6 +185,11 @@ func (call *Call) done() {
 // set of services at the other end of the connection.
 // It adds a buffer to the write side of the connection so
 // the header and payload are sent as a unit.
+//
+// The read and write halves of the connection are serialized independently,
+// so no interlocking is required. However each half may be accessed
+// concurrently so the implementation of conn should protect against
+// concurrent reads or concurrent writes.
 func NewClient(conn io.ReadWriteCloser) *Client {
 	encBuf := bufio.NewWriter(conn)
 	client := &gobClientCodec{conn, gob.NewDecoder(conn), gob.NewEncoder(encBuf), encBuf}
diff --git a/libgo/go/net/rpc/server.go b/libgo/go/net/rpc/server.go
index 96e6973..7bb6476 100644
--- a/libgo/go/net/rpc/server.go
+++ b/libgo/go/net/rpc/server.go
@@ -444,6 +444,7 @@ func (c *gobServerCodec) Close() error {
 // The caller typically invokes ServeConn in a go statement.
 // ServeConn uses the gob wire format (see package gob) on the
 // connection. To use an alternate codec, use ServeCodec.
+// See NewClient's comment for information about concurrent access.
 func (server *Server) ServeConn(conn io.ReadWriteCloser) {
 	buf := bufio.NewWriter(conn)
 	srv := &gobServerCodec{
@@ -653,12 +654,13 @@ func RegisterName(name string, rcvr interface{}) error {
 // write a response back. The server calls Close when finished with the
 // connection. ReadRequestBody may be called with a nil
 // argument to force the body of the request to be read and discarded.
+// See NewClient's comment for information about concurrent access.
 type ServerCodec interface {
 	ReadRequestHeader(*Request) error
 	ReadRequestBody(interface{}) error
-	// WriteResponse must be safe for concurrent use by multiple goroutines.
 	WriteResponse(*Response, interface{}) error
 
+	// Close can be called multiple times and must be idempotent.
 	Close() error
 }
 
@@ -667,6 +669,7 @@ type ServerCodec interface {
 // The caller typically invokes ServeConn in a go statement.
 // ServeConn uses the gob wire format (see package gob) on the
 // connection. To use an alternate codec, use ServeCodec.
+// See NewClient's comment for information about concurrent access.
 func ServeConn(conn io.ReadWriteCloser) {
 	DefaultServer.ServeConn(conn)
 }