diff --git a/client/client.go b/client/client.go
index 3f281fd..5814076 100644
--- a/client/client.go
+++ b/client/client.go
@@ -36,7 +36,8 @@ type client struct {
 	ch         ClientHandler
 	rwcHandler ClientReadWriteCloseHandler
 
-	conn interface{}
+	conn    interface{}
+	decoder interface{}
 
 	pendingRequestsCount uint32
 	pendingRequests      map[uint64]*RequestState
@@ -46,18 +47,21 @@ type client struct {
 
 	stopChan chan struct{}
 	stopWg   sync.WaitGroup
+
+	requestMtx  sync.Mutex
+	responseMtx sync.Mutex
 }
 
 func (c *client) Connect() error {
 	var err error
 
 	if nil == c.ch {
-		panic("RPC Client: Client handler must be specified.")
+		return fmt.Errorf("RPC Client: Client handler must be specified")
 	}
 	c.ch.Validate()
 
 	if nil == c.rwcHandler {
-		panic("RPC Client: Client RWC handler must be specified.")
+		return fmt.Errorf("RPC Client: Client RWC handler must be specified")
 	}
 	c.rwcHandler.Validate()
 
@@ -67,12 +71,18 @@ func (c *client) Connect() error {
 	c.ctx = c.ch.ClientContext(nil)
 
 	if err := c.ch.Init(c.ctx); nil != err {
-		logging.Logger().Panicf("RPC Client: Initialization of client has been failed %v", err)
+		return fmt.Errorf("RPC Client: Initialization of client has been failed %v", err)
 	}
 
 	if c.conn, err = c.rwcHandler.Connect(c.ctx); nil != err {
 		return err
 	}
+
+	c.decoder, err = c.rwcHandler.NewDecoder(c.ctx, c.ch.GetCodec(), c.conn)
+	if nil != err {
+		return fmt.Errorf("RPC Client: Cannot build rpc decoder")
+	}
+
 	c.stopChan = make(chan struct{})
 	c.requestQueueChan = make(chan *RequestState, c.ch.GetPendingRequests())
 	c.pendingRequests = make(map[uint64]*RequestState)
@@ -303,7 +313,9 @@ func (c *client) rpcWriter(stopChan <-chan struct{}, writerDone chan<- error) {
 			return
 		}
 
+		c.requestMtx.Lock()
 		err = c.rwcHandler.WriteRequest(c.ctx, c.ch.GetCodec(), c.conn, rs.Method, rs.Args, requestID)
+		c.requestMtx.Unlock()
 		if !rs.hasResponse {
 			rs.Error = err
 			rs.Done()
@@ -337,7 +349,9 @@ func (c *client) rpcReader(readerDone chan<- error) {
 			err = io.EOF
 			return
 		}
-		resCodec, err := c.rwcHandler.ReadResponse(c.ctx, c.ch.GetCodec(), c.conn)
+		c.responseMtx.Lock()
+		resCodec, err := c.rwcHandler.ReadResponse(c.ctx, c.ch.GetCodec(), c.decoder)
+		c.responseMtx.Unlock()
 		if nil != err {
 			if err == io.ErrUnexpectedEOF || err == io.EOF {
 				logging.Logger().Infof("Client: disconnected from server")
diff --git a/client/client_rwc_handler.go b/client/client_rwc_handler.go
index 9693c51..d5670c7 100644
--- a/client/client_rwc_handler.go
+++ b/client/client_rwc_handler.go
@@ -4,7 +4,8 @@ import "git.loafle.net/commons_go/rpc/protocol"
 
 type ClientReadWriteCloseHandler interface {
 	Connect(clientCTX ClientContext) (interface{}, error)
-	ReadResponse(clientCTX ClientContext, codec protocol.ClientCodec, conn interface{}) (protocol.ClientResponseCodec, error)
+	NewDecoder(clientCTX ClientContext, codec protocol.ClientCodec, conn interface{}) (interface{}, error)
+	ReadResponse(clientCTX ClientContext, codec protocol.ClientCodec, decoder interface{}) (protocol.ClientResponseCodec, error)
 	WriteRequest(clientCTX ClientContext, codec protocol.ClientCodec, conn interface{}, method string, params []interface{}, id interface{}) error
 	Disconnect(clientCTX ClientContext, conn interface{})
 
diff --git a/client/client_rwc_handlers.go b/client/client_rwc_handlers.go
index 6e98f42..559d5c0 100644
--- a/client/client_rwc_handlers.go
+++ b/client/client_rwc_handlers.go
@@ -2,21 +2,22 @@ package client
 
 import (
 	"fmt"
-	"sync"
 
 	"git.loafle.net/commons_go/rpc/protocol"
 )
 
 type ClientReadWriteCloseHandlers struct {
-	ReadMtx  sync.Mutex
-	WriteMtx sync.Mutex
 }
 
 func (crwch *ClientReadWriteCloseHandlers) Connect(clientCTX ClientContext) (interface{}, error) {
 	return nil, fmt.Errorf("RPC Client RWC Handler: ClientHandlers method[Connect] is not implement")
 }
 
-func (crwch *ClientReadWriteCloseHandlers) ReadResponse(clientCTX ClientContext, codec protocol.ClientCodec, conn interface{}) (protocol.ClientResponseCodec, error) {
+func (crwch *ClientReadWriteCloseHandlers) NewDecoder(clientCTX ClientContext, codec protocol.ClientCodec, conn interface{}) (interface{}, error) {
+	return nil, fmt.Errorf("RPC Client RWC Handler: NewDecoder is not implemented")
+}
+
+func (crwch *ClientReadWriteCloseHandlers) ReadResponse(clientCTX ClientContext, codec protocol.ClientCodec, decoder interface{}) (protocol.ClientResponseCodec, error) {
 	return nil, fmt.Errorf("RPC Client RWC Handler: ClientHandlers method[ReadResponse] is not implement")
 }
 
diff --git a/client/rwc/socket/client_rwc_handlers.go b/client/rwc/socket/client_rwc_handlers.go
index 95d2516..56a52eb 100644
--- a/client/rwc/socket/client_rwc_handlers.go
+++ b/client/rwc/socket/client_rwc_handlers.go
@@ -24,12 +24,14 @@ func (crwch *ClientReadWriteCloseHandlers) Connect(clientCTX client.ClientContex
 	return csc.NewSocket(crwch.SocketBuilder, clientCTX)
 }
 
-func (crwch *ClientReadWriteCloseHandlers) ReadResponse(clientCTX client.ClientContext, codec protocol.ClientCodec, conn interface{}) (protocol.ClientResponseCodec, error) {
+func (crwch *ClientReadWriteCloseHandlers) NewDecoder(clientCTX client.ClientContext, codec protocol.ClientCodec, conn interface{}) (interface{}, error) {
 	soc := conn.(csc.Socket)
 
-	crwch.ReadMtx.Lock()
-	resCodec, err := codec.NewResponse(soc)
-	crwch.ReadMtx.Unlock()
+	return codec.NewDecoder(soc), nil
+}
+
+func (crwch *ClientReadWriteCloseHandlers) ReadResponse(clientCTX client.ClientContext, codec protocol.ClientCodec, decoder interface{}) (protocol.ClientResponseCodec, error) {
+	resCodec, err := codec.NewResponse(decoder)
 
 	return resCodec, err
 }
@@ -40,9 +42,7 @@ func (crwch *ClientReadWriteCloseHandlers) WriteRequest(clientCTX client.ClientC
 	)
 	soc := conn.(csc.Socket)
 
-	crwch.WriteMtx.Lock()
 	wErr = codec.WriteRequest(soc, method, params, id)
-	crwch.WriteMtx.Unlock()
 
 	return wErr
 }
diff --git a/client/rwc/websocket/fasthttp/client_rwc_handlers.go b/client/rwc/websocket/fasthttp/client_rwc_handlers.go
index 05c85f8..d216301 100644
--- a/client/rwc/websocket/fasthttp/client_rwc_handlers.go
+++ b/client/rwc/websocket/fasthttp/client_rwc_handlers.go
@@ -27,13 +27,18 @@ func (crwch *ClientReadWriteCloseHandlers) Connect(clientCTX client.ClientContex
 	return cwfc.NewSocket(crwch.SocketBuilder, clientCTX)
 }
 
-func (crwch *ClientReadWriteCloseHandlers) ReadResponse(clientCTX client.ClientContext, codec protocol.ClientCodec, conn interface{}) (protocol.ClientResponseCodec, error) {
+func (crwch *ClientReadWriteCloseHandlers) NewDecoder(clientCTX client.ClientContext, codec protocol.ClientCodec, conn interface{}) (interface{}, error) {
 	soc := conn.(cwfc.Socket)
-
-	crwch.ReadMtx.Lock()
 	_, r, err := soc.NextReader()
-	resCodec, err := codec.NewResponse(r)
-	crwch.ReadMtx.Unlock()
+	if nil != err {
+		return nil, err
+	}
+
+	return codec.NewDecoder(r), nil
+}
+
+func (crwch *ClientReadWriteCloseHandlers) ReadResponse(clientCTX client.ClientContext, codec protocol.ClientCodec, decoder interface{}) (protocol.ClientResponseCodec, error) {
+	resCodec, err := codec.NewResponse(decoder)
 
 	return resCodec, err
 }
@@ -45,10 +50,8 @@ func (crwch *ClientReadWriteCloseHandlers) WriteRequest(clientCTX client.ClientC
 	)
 	soc := conn.(cwfc.Socket)
 
-	crwch.WriteMtx.Lock()
 	wc, wErr = soc.NextWriter(websocket.TextMessage)
 	if nil != wErr {
-		crwch.WriteMtx.Unlock()
 		return wErr
 	}
 	defer func() {
@@ -57,8 +60,6 @@ func (crwch *ClientReadWriteCloseHandlers) WriteRequest(clientCTX client.ClientC
 
 	wErr = codec.WriteRequest(wc, method, params, id)
 
-	crwch.WriteMtx.Unlock()
-
 	return wErr
 }
 
diff --git a/codec/codec.go b/codec/codec.go
deleted file mode 100644
index 52643d0..0000000
--- a/codec/codec.go
+++ /dev/null
@@ -1,23 +0,0 @@
-package codec
-
-import "io"
-
-// Codec interface contains the encoder for response or decoder for request.
-// Eg. gzip, flate compressions.
-type Codec interface {
-	Encode(w io.Writer) io.Writer
-	Decode(r io.Reader) io.Reader
-}
-
-type codec struct {
-}
-
-func (_ *codec) Encode(w io.Writer) io.Writer {
-	return w
-}
-
-func (_ *codec) Decode(r io.Reader) io.Reader {
-	return r
-}
-
-var DefaultCodec = &codec{}
diff --git a/codec/selector.go b/codec/selector.go
deleted file mode 100644
index 902117f..0000000
--- a/codec/selector.go
+++ /dev/null
@@ -1,25 +0,0 @@
-package codec
-
-import "io"
-
-// CodecSelector interface provides a way to select encoder using the http
-// request. Typically people can use this to check HEADER of the request and
-// figure out client capabilities.
-// Eg. "Accept-Encoding" tells about supported compressions.
-type CodecSelector interface {
-	SelectByReader(r io.Reader) Codec
-	SelectByWriter(w io.Writer) Codec
-}
-
-type codecSelector struct {
-}
-
-func (_ *codecSelector) SelectByReader(_ io.Reader) Codec {
-	return DefaultCodec
-}
-
-func (_ *codecSelector) SelectByWriter(_ io.Writer) Codec {
-	return DefaultCodec
-}
-
-var DefaultCodecSelector = &codecSelector{}
diff --git a/protocol/client_codec.go b/protocol/client_codec.go
index b5a58bc..db3b291 100644
--- a/protocol/client_codec.go
+++ b/protocol/client_codec.go
@@ -6,8 +6,10 @@ import (
 
 // ClientCodec creates a ClientCodecRequest to process each request.
 type ClientCodec interface {
+	NewDecoder(r io.Reader) interface{}
+
 	WriteRequest(w io.Writer, method string, args []interface{}, id interface{}) error
-	NewResponse(rc io.Reader) (ClientResponseCodec, error)
+	NewResponse(decoder interface{}) (ClientResponseCodec, error)
 }
 
 type ClientResponseCodec interface {
diff --git a/protocol/json/client.go b/protocol/json/client.go
index 3ead2d6..1a8f1c0 100644
--- a/protocol/json/client.go
+++ b/protocol/json/client.go
@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"io"
 
-	"git.loafle.net/commons_go/rpc/codec"
 	"git.loafle.net/commons_go/rpc/protocol"
 )
 
@@ -12,19 +11,17 @@ import (
 // Codec
 // ----------------------------------------------------------------------------
 
-// NewCustomClientCodec returns a new JSON Codec based on passed encoder selector.
-func NewCustomClientCodec(codecSel codec.CodecSelector) protocol.ClientCodec {
-	return &ClientCodec{codecSel: codecSel}
-}
-
 // NewClientCodec returns a new JSON Codec.
 func NewClientCodec() protocol.ClientCodec {
-	return NewCustomClientCodec(codec.DefaultCodecSelector)
+	return &ClientCodec{}
 }
 
 // ClientCodec creates a ClientCodecRequest to process each request.
 type ClientCodec struct {
-	codecSel codec.CodecSelector
+}
+
+func (cc *ClientCodec) NewDecoder(r io.Reader) interface{} {
+	return json.NewDecoder(r)
 }
 
 func (cc *ClientCodec) WriteRequest(w io.Writer, method string, args []interface{}, id interface{}) error {
@@ -40,7 +37,7 @@ func (cc *ClientCodec) WriteRequest(w io.Writer, method string, args []interface
 		ID:      id,
 	}
 
-	encoder := json.NewEncoder(cc.codecSel.SelectByWriter(w).Encode(w))
+	encoder := json.NewEncoder(w)
 	if err := encoder.Encode(req); nil != err {
 		return err
 	}
@@ -49,6 +46,6 @@ func (cc *ClientCodec) WriteRequest(w io.Writer, method string, args []interface
 }
 
 // NewMessage returns a ClientMessageCodec.
-func (cc *ClientCodec) NewResponse(r io.Reader) (protocol.ClientResponseCodec, error) {
-	return newClientResponseCodec(r, cc.codecSel.SelectByReader(r))
+func (cc *ClientCodec) NewResponse(decoder interface{}) (protocol.ClientResponseCodec, error) {
+	return newClientResponseCodec(decoder.(*json.Decoder))
 }
diff --git a/protocol/json/client_notification.go b/protocol/json/client_notification.go
index 0c96da2..1229427 100644
--- a/protocol/json/client_notification.go
+++ b/protocol/json/client_notification.go
@@ -3,7 +3,6 @@ package json
 import (
 	"encoding/json"
 
-	"git.loafle.net/commons_go/rpc/codec"
 	crp "git.loafle.net/commons_go/rpc/protocol"
 	cuej "git.loafle.net/commons_go/util/encoding/json"
 )
@@ -21,9 +20,8 @@ type clientNotification struct {
 
 // ClientNotificationCodec decodes and encodes a single notification.
 type ClientNotificationCodec struct {
-	noti  *clientNotification
-	err   error
-	codec codec.Codec
+	noti *clientNotification
+	err  error
 }
 
 func (cnc *ClientNotificationCodec) HasResponse() bool {
diff --git a/protocol/json/client_response.go b/protocol/json/client_response.go
index eddb1da..2ec41d3 100644
--- a/protocol/json/client_response.go
+++ b/protocol/json/client_response.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 
-	"git.loafle.net/commons_go/rpc/codec"
 	"git.loafle.net/commons_go/rpc/protocol"
 	crp "git.loafle.net/commons_go/rpc/protocol"
 )
@@ -23,9 +22,8 @@ type clientResponse struct {
 
 // ClientResponseCodec decodes and encodes a single request.
 type ClientResponseCodec struct {
-	res   *clientResponse
-	err   error
-	codec codec.Codec
+	res *clientResponse
+	err error
 }
 
 func (crc *ClientResponseCodec) ID() interface{} {
@@ -61,15 +59,11 @@ func (crc *ClientResponseCodec) Notification() (protocol.ClientNotificationCodec
 		return nil, err
 	}
 
-	return &ClientNotificationCodec{noti: noti, err: err, codec: crc.codec}, nil
+	return &ClientNotificationCodec{noti: noti, err: err}, nil
 }
 
 // newClientMessageCodec returns a new ClientMessageCodec.
-func newClientResponseCodec(r io.Reader, codec codec.Codec) (protocol.ClientResponseCodec, error) {
-	decoder := json.NewDecoder(r)
-	if nil == r {
-		return nil, io.EOF
-	}
+func newClientResponseCodec(decoder *json.Decoder) (protocol.ClientResponseCodec, error) {
 	decoder.UseNumber()
 
 	res := &clientResponse{}
@@ -92,5 +86,5 @@ func newClientResponseCodec(r io.Reader, codec codec.Codec) (protocol.ClientResp
 		}
 	}
 
-	return &ClientResponseCodec{res: res, err: err, codec: codec}, nil
+	return &ClientResponseCodec{res: res, err: err}, nil
 }
diff --git a/protocol/json/server.go b/protocol/json/server.go
index cbc38f9..1eb5fb2 100644
--- a/protocol/json/server.go
+++ b/protocol/json/server.go
@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"io"
 
-	"git.loafle.net/commons_go/rpc/codec"
 	"git.loafle.net/commons_go/rpc/protocol"
 )
 
@@ -14,24 +13,22 @@ var null = json.RawMessage([]byte("null"))
 // Codec
 // ----------------------------------------------------------------------------
 
-// NewCustomServerCodec returns a new JSON Codec based on passed encoder selector.
-func NewCustomServerCodec(codecSel codec.CodecSelector) protocol.ServerCodec {
-	return &ServerCodec{codecSel: codecSel}
-}
-
 // NewServerCodec returns a new JSON Codec.
 func NewServerCodec() protocol.ServerCodec {
-	return NewCustomServerCodec(codec.DefaultCodecSelector)
+	return &ServerCodec{}
 }
 
 // ServerCodec creates a ServerRequestCodec to process each request.
 type ServerCodec struct {
-	codecSel codec.CodecSelector
+}
+
+func (sc *ServerCodec) NewDecoder(r io.Reader) interface{} {
+	return json.NewDecoder(r)
 }
 
 // NewRequest returns a ServerRequestCodec.
-func (sc *ServerCodec) NewRequest(r io.Reader) (protocol.ServerRequestCodec, error) {
-	return newServerRequestCodec(r, sc.codecSel.SelectByReader(r))
+func (sc *ServerCodec) NewRequest(decoder interface{}) (protocol.ServerRequestCodec, error) {
+	return newServerRequestCodec(decoder.(*json.Decoder))
 }
 
 // WriteNotification send a notification from server to client.
@@ -44,7 +41,7 @@ func (sc *ServerCodec) WriteNotification(w io.Writer, method string, args []inte
 	noti := &serverNotification{Method: method, Params: params}
 	res := &serverResponse{Version: Version, Result: noti}
 
-	encoder := json.NewEncoder(sc.codecSel.SelectByWriter(w).Encode(w))
+	encoder := json.NewEncoder(w)
 	// Not sure in which case will this happen. But seems harmless.
 	if err := encoder.Encode(res); nil != err {
 		return err
diff --git a/protocol/json/server_request.go b/protocol/json/server_request.go
index a446101..1361527 100644
--- a/protocol/json/server_request.go
+++ b/protocol/json/server_request.go
@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"io"
 
-	"git.loafle.net/commons_go/rpc/codec"
 	"git.loafle.net/commons_go/rpc/protocol"
 	crp "git.loafle.net/commons_go/rpc/protocol"
 	cuej "git.loafle.net/commons_go/util/encoding/json"
@@ -36,14 +35,8 @@ type serverRequest struct {
 // ----------------------------------------------------------------------------
 
 // newRequestCodec returns a new ServerRequestCodec.
-func newServerRequestCodec(r io.Reader, codec codec.Codec) (protocol.ServerRequestCodec, error) {
+func newServerRequestCodec(decoder *json.Decoder) (protocol.ServerRequestCodec, error) {
 	// Decode the request body and check if RPC method is valid.
-	decoder := json.NewDecoder(r)
-	if nil == r {
-		return nil, io.EOF
-	}
-	decoder.UseNumber()
-
 	req := &serverRequest{}
 	err := decoder.Decode(req)
 	if err == io.ErrUnexpectedEOF || err == io.EOF {
@@ -64,14 +57,13 @@ func newServerRequestCodec(r io.Reader, codec codec.Codec) (protocol.ServerReque
 		}
 	}
 
-	return &ServerRequestCodec{req: req, err: err, codec: codec}, nil
+	return &ServerRequestCodec{req: req, err: err}, nil
 }
 
 // ServerRequestCodec decodes and encodes a single request.
 type ServerRequestCodec struct {
-	req   *serverRequest
-	err   error
-	codec codec.Codec
+	req *serverRequest
+	err error
 }
 
 func (src *ServerRequestCodec) HasResponse() bool {
@@ -155,7 +147,7 @@ func (src *ServerRequestCodec) WriteError(w io.Writer, status int, err error) er
 func (src *ServerRequestCodec) writeServerResponse(w io.Writer, res *serverResponse) error {
 	// ID is null for notifications and they don't have a response.
 	if src.req.ID != nil {
-		encoder := json.NewEncoder(src.codec.Encode(w))
+		encoder := json.NewEncoder(w)
 		// Not sure in which case will this happen. But seems harmless.
 		if err := encoder.Encode(res); nil != err {
 			return err
diff --git a/protocol/server_codec.go b/protocol/server_codec.go
index 92f98de..15d74b7 100644
--- a/protocol/server_codec.go
+++ b/protocol/server_codec.go
@@ -6,7 +6,9 @@ import (
 
 // ServerCodec creates a ServerRequestCodec to process each request.
 type ServerCodec interface {
-	NewRequest(r io.Reader) (ServerRequestCodec, error)
+	NewDecoder(r io.Reader) interface{}
+
+	NewRequest(decoder interface{}) (ServerRequestCodec, error)
 	WriteNotification(w io.Writer, method string, args []interface{}) error
 }
 
diff --git a/server/rwc/socket/servlet_rwc_handlers.go b/server/rwc/socket/servlet_rwc_handlers.go
index e3b9b1c..7206ceb 100644
--- a/server/rwc/socket/servlet_rwc_handlers.go
+++ b/server/rwc/socket/servlet_rwc_handlers.go
@@ -14,12 +14,14 @@ type ServletReadWriteCloseHandlers struct {
 	rpc.ServletReadWriteCloseHandlers
 }
 
-func (srwch *ServletReadWriteCloseHandlers) ReadRequest(servletCTX rpc.ServletContext, codec protocol.ServerCodec, conn interface{}) (protocol.ServerRequestCodec, error) {
+func (srwch *ServletReadWriteCloseHandlers) NewDecoder(servletCTX rpc.ServletContext, codec protocol.ServerCodec, conn interface{}) (interface{}, error) {
 	soc := conn.(server.Socket)
 
-	srwch.ReadMtx.Lock()
-	reqCodec, err := codec.NewRequest(soc)
-	srwch.ReadMtx.Unlock()
+	return codec.NewDecoder(soc), nil
+}
+
+func (srwch *ServletReadWriteCloseHandlers) ReadRequest(servletCTX rpc.ServletContext, codec protocol.ServerCodec, decoder interface{}) (protocol.ServerRequestCodec, error) {
+	reqCodec, err := codec.NewRequest(decoder)
 
 	return reqCodec, err
 }
@@ -30,13 +32,11 @@ func (srwch *ServletReadWriteCloseHandlers) WriteResponse(servletCTX rpc.Servlet
 	)
 	soc := conn.(server.Socket)
 
-	srwch.WriteMtx.Lock()
 	if nil != err {
 		wErr = reqCodec.WriteError(soc, 500, err)
 	} else {
 		wErr = reqCodec.WriteResponse(soc, result)
 	}
-	srwch.WriteMtx.Unlock()
 
 	return wErr
 }
@@ -47,9 +47,7 @@ func (srwch *ServletReadWriteCloseHandlers) WriteNotification(servletCTX rpc.Ser
 	)
 	soc := conn.(server.Socket)
 
-	srwch.WriteMtx.Lock()
 	wErr = codec.WriteNotification(soc, method, params)
-	srwch.WriteMtx.Unlock()
 
 	return wErr
 }
diff --git a/server/rwc/websocket/fasthttp/servlet_rwc_handlers.go b/server/rwc/websocket/fasthttp/servlet_rwc_handlers.go
index 2b4f0c2..3a8e120 100644
--- a/server/rwc/websocket/fasthttp/servlet_rwc_handlers.go
+++ b/server/rwc/websocket/fasthttp/servlet_rwc_handlers.go
@@ -17,13 +17,18 @@ type ServletReadWriteCloseHandlers struct {
 	rpc.ServletReadWriteCloseHandlers
 }
 
-func (srwch *ServletReadWriteCloseHandlers) ReadRequest(servletCTX rpc.ServletContext, codec protocol.ServerCodec, conn interface{}) (protocol.ServerRequestCodec, error) {
+func (srwch *ServletReadWriteCloseHandlers) NewDecoder(servletCTX rpc.ServletContext, codec protocol.ServerCodec, conn interface{}) (interface{}, error) {
 	soc := conn.(cwf.Socket)
-
-	srwch.ReadMtx.Lock()
 	_, r, err := soc.NextReader()
-	requestCodec, err := codec.NewRequest(r)
-	srwch.ReadMtx.Unlock()
+	if nil != err {
+		return nil, err
+	}
+
+	return codec.NewDecoder(r), nil
+}
+
+func (srwch *ServletReadWriteCloseHandlers) ReadRequest(servletCTX rpc.ServletContext, codec protocol.ServerCodec, decoder interface{}) (protocol.ServerRequestCodec, error) {
+	requestCodec, err := codec.NewRequest(decoder)
 
 	return requestCodec, err
 }
@@ -35,10 +40,8 @@ func (srwch *ServletReadWriteCloseHandlers) WriteResponse(servletCTX rpc.Servlet
 	)
 	soc := conn.(cwf.Socket)
 
-	srwch.WriteMtx.Lock()
 	wc, wErr = soc.NextWriter(websocket.TextMessage)
 	if nil != wErr {
-		srwch.WriteMtx.Unlock()
 		return wErr
 	}
 
@@ -51,7 +54,6 @@ func (srwch *ServletReadWriteCloseHandlers) WriteResponse(servletCTX rpc.Servlet
 	} else {
 		wErr = requestCodec.WriteResponse(wc, result)
 	}
-	srwch.WriteMtx.Unlock()
 
 	return wErr
 }
@@ -63,10 +65,8 @@ func (srwch *ServletReadWriteCloseHandlers) WriteNotification(servletCTX rpc.Ser
 	)
 	soc := conn.(cwf.Socket)
 
-	srwch.WriteMtx.Lock()
 	wc, wErr = soc.NextWriter(websocket.TextMessage)
 	if nil != wErr {
-		srwch.WriteMtx.Unlock()
 		return wErr
 	}
 
@@ -75,7 +75,6 @@ func (srwch *ServletReadWriteCloseHandlers) WriteNotification(servletCTX rpc.Ser
 	}()
 
 	wErr = codec.WriteNotification(wc, method, params)
-	srwch.WriteMtx.Unlock()
 
 	return wErr
 }
diff --git a/servlet.go b/servlet.go
index 2574b8c..1e5f5d6 100644
--- a/servlet.go
+++ b/servlet.go
@@ -36,11 +36,13 @@ type rpcServlet struct {
 
 	conn        interface{}
 	serverCodec protocol.ServerCodec
+	decoder     interface{}
 
 	stopChan chan struct{}
 	stopWg   sync.WaitGroup
 
-	sendMtx sync.RWMutex
+	requestMtx  sync.Mutex
+	responseMTX sync.Mutex
 }
 
 func (s *rpcServlet) Context() ServletContext {
@@ -70,6 +72,10 @@ func (s *rpcServlet) Start(parentCTX cuc.Context, conn interface{}, doneChan cha
 
 	s.conn = conn
 	s.serverCodec = sc
+	s.decoder, err = s.rwcSH.NewDecoder(s.ctx, sc, conn)
+	if nil != err {
+		return fmt.Errorf("RPC Servlet: Cannot build rpc decoder")
+	}
 
 	if err := s.sh.Init(s.ctx); nil != err {
 		return fmt.Errorf("RPC Servlet: Initialization of servlet has been failed %v", err)
@@ -168,7 +174,9 @@ func handleReader(s *rpcServlet, stopChan chan struct{}, doneChan chan error) {
 			return
 		}
 
-		requestCodec, err := s.rwcSH.ReadRequest(s.ctx, s.serverCodec, s.conn)
+		s.requestMtx.Lock()
+		requestCodec, err := s.rwcSH.ReadRequest(s.ctx, s.serverCodec, s.decoder)
+		s.requestMtx.Unlock()
 		if nil != err {
 			if err == io.ErrUnexpectedEOF || err == io.EOF {
 				err = fmt.Errorf("RPC Server: Disconnected from client")
@@ -221,6 +229,7 @@ func handleWriter(s *rpcServlet, stopChan chan struct{}, doneChan chan error) {
 			return
 		}
 
+		s.responseMTX.Lock()
 		if nil != rs.requestCodec {
 			if err := s.rwcSH.WriteResponse(s.ctx, s.conn, rs.requestCodec, rs.result, rs.err); nil != err {
 				logging.Logger().Errorf("RPC Servlet: response error %v", err)
@@ -230,9 +239,9 @@ func handleWriter(s *rpcServlet, stopChan chan struct{}, doneChan chan error) {
 				logging.Logger().Errorf("RPC Servlet: notification error %v", err)
 			}
 		}
+		s.responseMTX.Unlock()
 
 	}
-
 }
 
 func handleRequest(s *rpcServlet, requestCodec protocol.ServerRequestCodec) {
diff --git a/servlet_rwc_handler.go b/servlet_rwc_handler.go
index c0e2ef7..cd2b2b5 100644
--- a/servlet_rwc_handler.go
+++ b/servlet_rwc_handler.go
@@ -3,7 +3,9 @@ package rpc
 import "git.loafle.net/commons_go/rpc/protocol"
 
 type ServletReadWriteCloseHandler interface {
-	ReadRequest(servletCTX ServletContext, codec protocol.ServerCodec, conn interface{}) (protocol.ServerRequestCodec, error)
+	NewDecoder(servletCTX ServletContext, codec protocol.ServerCodec, conn interface{}) (interface{}, error)
+
+	ReadRequest(servletCTX ServletContext, codec protocol.ServerCodec, decoder interface{}) (protocol.ServerRequestCodec, error)
 	WriteResponse(servletCTX ServletContext, conn interface{}, requestCodec protocol.ServerRequestCodec, result interface{}, err error) error
 	WriteNotification(servletCTX ServletContext, conn interface{}, codec protocol.ServerCodec, method string, params []interface{}) error
 
diff --git a/servlet_rwc_handlers.go b/servlet_rwc_handlers.go
index 59a2973..d97649f 100644
--- a/servlet_rwc_handlers.go
+++ b/servlet_rwc_handlers.go
@@ -2,17 +2,20 @@ package rpc
 
 import (
 	"fmt"
-	"sync"
 
+	"git.loafle.net/commons_go/logging"
 	"git.loafle.net/commons_go/rpc/protocol"
 )
 
 type ServletReadWriteCloseHandlers struct {
-	ReadMtx  sync.Mutex
-	WriteMtx sync.Mutex
 }
 
-func (srwch *ServletReadWriteCloseHandlers) ReadRequest(servletCTX ServletContext, codec protocol.ServerCodec, conn interface{}) (protocol.ServerRequestCodec, error) {
+func (srwch *ServletReadWriteCloseHandlers) NewDecoder(servletCTX ServletContext, codec protocol.ServerCodec, conn interface{}) interface{} {
+	logging.Logger().Errorf("Servlet RWC Handler: NewDecoder is not implemented")
+	return nil
+}
+
+func (srwch *ServletReadWriteCloseHandlers) ReadRequest(servletCTX ServletContext, codec protocol.ServerCodec, decoder interface{}) (protocol.ServerRequestCodec, error) {
 	return nil, fmt.Errorf("Servlet RWC Handler: ReadRequest is not implemented")
 }