From 5058fca209664e9f2ccab680e6a920b1503f4dfa Mon Sep 17 00:00:00 2001
From: seeflood <349895584@qq.com>
Date: Fri, 17 Dec 2021 16:31:11 +0800
Subject: [PATCH 1/8] parallel tests

---
 .github/workflows/github-actions.yml | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/github-actions.yml b/.github/workflows/github-actions.yml
index 0c311740bf..352d6b29e1 100644
--- a/.github/workflows/github-actions.yml
+++ b/.github/workflows/github-actions.yml
@@ -69,6 +69,17 @@ jobs:
       - name: Post Coverage
         run: bash <(curl -s https://codecov.io/bash)
 
-      - name: integrate
-        run: make wasm-integrate
+  integrate:
+    name: integrate
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: 1.15
 
+      - name: Check out code
+        uses: actions/checkout@v2
+
+      - name: Run Integrate tests.
+        run: make wasm-integrate

From c8c1c4554b1d2c68669ec51dfc9e1f0b9eb7bfdf Mon Sep 17 00:00:00 2001
From: seeflood <349895584@qq.com>
Date: Sat, 18 Dec 2021 00:02:49 +0800
Subject: [PATCH 2/8] modify parameter

---
 pkg/grpc/dapr/dapr_api.go                | 22 ++++++--------------
 pkg/grpc/dapr/dapr_api_test.go           |  7 +++++--
 pkg/grpc/default_api/api.go              | 17 ++++------------
 pkg/grpc/grpc_api.go                     | 24 +++++++++++++---------
 pkg/integrate/api/helloworld/grpc_api.go | 23 ++-------------------
 pkg/runtime/runtime.go                   | 26 +++++++++++++-----------
 6 files changed, 45 insertions(+), 74 deletions(-)

diff --git a/pkg/grpc/dapr/dapr_api.go b/pkg/grpc/dapr/dapr_api.go
index aba19121dc..f89cbb30a3 100644
--- a/pkg/grpc/dapr/dapr_api.go
+++ b/pkg/grpc/dapr/dapr_api.go
@@ -158,28 +158,18 @@ func (d *daprGrpcAPI) InvokeBinding(ctx context.Context, in *runtime.InvokeBindi
 // NewDaprAPI_Alpha construct a grpc_api.GrpcAPI which implements DaprServer.
 // Currently it only support Dapr's InvokeService and InvokeBinding API.
 // Note: this feature is still in Alpha state and we don't recommend that you use it in your production environment.
-func NewDaprAPI_Alpha(
-	appId string,
-	hellos map[string]hello.HelloService,
-	configStores map[string]configstores.Store,
-	rpcs map[string]rpc.Invoker,
-	pubSubs map[string]pubsub.PubSub,
-	stateStores map[string]state.Store,
-	files map[string]file.File,
-	lockStores map[string]lock.LockStore,
-	sequencers map[string]sequencer.Store,
-	sendToOutputBindingFn func(name string, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error),
-) grpc_api.GrpcAPI {
+func NewDaprAPI_Alpha(ac *grpc_api.ApplicationContext) grpc_api.GrpcAPI {
 	// filter out transactionalStateStores
 	transactionalStateStores := map[string]state.TransactionalStore{}
-	for key, store := range stateStores {
+	for key, store := range ac.StateStores {
 		if state.FeatureTransactional.IsPresent(store.Features()) {
 			transactionalStateStores[key] = store.(state.TransactionalStore)
 		}
 	}
-	return NewDaprServer(appId, hellos, configStores, rpcs, pubSubs,
-		stateStores, transactionalStateStores,
-		files, lockStores, sequencers, sendToOutputBindingFn)
+	return NewDaprServer(ac.AppId,
+		ac.Hellos, ac.ConfigStores, ac.Rpcs, ac.PubSubs, ac.StateStores, transactionalStateStores,
+		ac.Files, ac.LockStores, ac.Sequencers,
+		ac.SendToOutputBindingFn)
 }
 
 func NewDaprServer(
diff --git a/pkg/grpc/dapr/dapr_api_test.go b/pkg/grpc/dapr/dapr_api_test.go
index e747eb4dfe..35524cf292 100644
--- a/pkg/grpc/dapr/dapr_api_test.go
+++ b/pkg/grpc/dapr/dapr_api_test.go
@@ -24,6 +24,7 @@ import (
 	"github.com/golang/mock/gomock"
 	"github.com/phayes/freeport"
 	"github.com/stretchr/testify/assert"
+	grpc_api "mosn.io/layotto/pkg/grpc"
 	mock_state "mosn.io/layotto/pkg/mock/components/state"
 	"net"
 	"testing"
@@ -63,13 +64,15 @@ func TestNewDaprAPI_Alpha(t *testing.T) {
 		mockTxStore,
 	}
 	// construct API
-	grpcAPI := NewDaprAPI_Alpha("", nil, nil, nil, nil, map[string]state.Store{"mock": store}, nil, nil, nil,
+	grpcAPI := NewDaprAPI_Alpha(&grpc_api.ApplicationContext{
+		"", nil, nil, nil, nil,
+		map[string]state.Store{"mock": store}, nil, nil, nil,
 		func(name string, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error) {
 			if name == "error-binding" {
 				return nil, errors.New("error when invoke binding")
 			}
 			return &bindings.InvokeResponse{Data: []byte("ok")}, nil
-		})
+		}})
 	err := grpcAPI.Init(nil)
 	if err != nil {
 		t.Errorf("grpcAPI.Init error")
diff --git a/pkg/grpc/default_api/api.go b/pkg/grpc/default_api/api.go
index 3eb132db99..88c1e7c450 100644
--- a/pkg/grpc/default_api/api.go
+++ b/pkg/grpc/default_api/api.go
@@ -159,19 +159,10 @@ func (a *api) Register(s *grpc.Server, registeredServer mgrpc.RegisteredServer)
 	return registeredServer, nil
 }
 
-func NewGrpcAPI(
-	appId string,
-	hellos map[string]hello.HelloService,
-	configStores map[string]configstores.Store,
-	rpcs map[string]rpc.Invoker,
-	pubSubs map[string]pubsub.PubSub,
-	stateStores map[string]state.Store,
-	files map[string]file.File,
-	lockStores map[string]lock.LockStore,
-	sequencers map[string]sequencer.Store,
-	sendToOutputBindingFn func(name string, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error),
-) grpc_api.GrpcAPI {
-	return NewAPI(appId, hellos, configStores, rpcs, pubSubs, stateStores, files, lockStores, sequencers, sendToOutputBindingFn)
+func NewGrpcAPI(ac *grpc_api.ApplicationContext) grpc_api.GrpcAPI {
+	return NewAPI(ac.AppId,
+		ac.Hellos, ac.ConfigStores, ac.Rpcs, ac.PubSubs, ac.StateStores, ac.Files, ac.LockStores, ac.Sequencers,
+		ac.SendToOutputBindingFn)
 }
 
 func NewAPI(
diff --git a/pkg/grpc/grpc_api.go b/pkg/grpc/grpc_api.go
index 4975a51d11..09f31596fd 100644
--- a/pkg/grpc/grpc_api.go
+++ b/pkg/grpc/grpc_api.go
@@ -40,14 +40,18 @@ type GrpcAPI interface {
 
 // NewGrpcAPI is the constructor of GrpcAPI
 type NewGrpcAPI func(
-	appId string,
-	hellos map[string]hello.HelloService,
-	configStores map[string]configstores.Store,
-	rpcs map[string]rpc.Invoker,
-	pubSubs map[string]pubsub.PubSub,
-	stateStores map[string]state.Store,
-	files map[string]file.File,
-	lockStores map[string]lock.LockStore,
-	sequencers map[string]sequencer.Store,
-	sendToOutputBindingFn func(name string, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error),
+	applicationContext *ApplicationContext,
 ) GrpcAPI
+
+type ApplicationContext struct {
+	AppId                 string
+	Hellos                map[string]hello.HelloService
+	ConfigStores          map[string]configstores.Store
+	Rpcs                  map[string]rpc.Invoker
+	PubSubs               map[string]pubsub.PubSub
+	StateStores           map[string]state.Store
+	Files                 map[string]file.File
+	LockStores            map[string]lock.LockStore
+	Sequencers            map[string]sequencer.Store
+	SendToOutputBindingFn func(name string, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error)
+}
diff --git a/pkg/integrate/api/helloworld/grpc_api.go b/pkg/integrate/api/helloworld/grpc_api.go
index 52e16f7285..f12bb1a65d 100644
--- a/pkg/integrate/api/helloworld/grpc_api.go
+++ b/pkg/integrate/api/helloworld/grpc_api.go
@@ -18,33 +18,14 @@ package helloworld
 
 import (
 	"context"
-	"github.com/dapr/components-contrib/bindings"
-	"github.com/dapr/components-contrib/pubsub"
-	"github.com/dapr/components-contrib/state"
 	rawGRPC "google.golang.org/grpc"
 	pb "google.golang.org/grpc/examples/helloworld/helloworld"
-	"mosn.io/layotto/components/configstores"
-	"mosn.io/layotto/components/file"
-	"mosn.io/layotto/components/hello"
-	"mosn.io/layotto/components/lock"
-	"mosn.io/layotto/components/rpc"
-	"mosn.io/layotto/components/sequencer"
 	"mosn.io/layotto/pkg/grpc"
+	grpc_api "mosn.io/layotto/pkg/grpc"
 	mgrpc "mosn.io/mosn/pkg/filter/network/grpc"
 )
 
-func NewHelloWorldAPI(
-	appId string,
-	hellos map[string]hello.HelloService,
-	configStores map[string]configstores.Store,
-	rpcs map[string]rpc.Invoker,
-	pubSubs map[string]pubsub.PubSub,
-	stateStores map[string]state.Store,
-	files map[string]file.File,
-	lockStores map[string]lock.LockStore,
-	sequencers map[string]sequencer.Store,
-	sendToOutputBindingFn func(name string, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error),
-) grpc.GrpcAPI {
+func NewHelloWorldAPI(ac *grpc_api.ApplicationContext) grpc.GrpcAPI {
 	return &server{}
 }
 
diff --git a/pkg/runtime/runtime.go b/pkg/runtime/runtime.go
index 9ecb44a31c..5226ea8067 100644
--- a/pkg/runtime/runtime.go
+++ b/pkg/runtime/runtime.go
@@ -156,19 +156,21 @@ func (m *MosnRuntime) Run(opts ...Option) (mgrpc.RegisteredServer, error) {
 	}
 	// create GrpcAPIs
 	var apis []grpc.GrpcAPI
+	ac := &grpc.ApplicationContext{
+		m.runtimeConfig.AppManagement.AppId,
+		m.hellos,
+		m.configStores,
+		m.rpcs,
+		m.pubSubs,
+		m.states,
+		m.files,
+		m.locks,
+		m.sequencers,
+		m.sendToOutputBinding,
+	}
+
 	for _, apiFactory := range o.apiFactorys {
-		api := apiFactory(
-			m.runtimeConfig.AppManagement.AppId,
-			m.hellos,
-			m.configStores,
-			m.rpcs,
-			m.pubSubs,
-			m.states,
-			m.files,
-			m.locks,
-			m.sequencers,
-			m.sendToOutputBinding,
-		)
+		api := apiFactory(ac)
 		// init the GrpcAPI
 		if err := api.Init(m.AppCallbackConn); err != nil {
 			return nil, err

From a9508314f4b155e08f648b096912a25a9bf6c902 Mon Sep 17 00:00:00 2001
From: seeflood <349895584@qq.com>
Date: Sat, 18 Dec 2021 13:35:36 +0800
Subject: [PATCH 3/8] move helloworld to a different package

---
 .../api => cmd/layotto_multiple_api}/helloworld/grpc_api.go   | 0
 cmd/layotto_multiple_api/main.go                              | 2 +-
 pkg/grpc/grpc_api.go                                          | 4 +---
 3 files changed, 2 insertions(+), 4 deletions(-)
 rename {pkg/integrate/api => cmd/layotto_multiple_api}/helloworld/grpc_api.go (100%)

diff --git a/pkg/integrate/api/helloworld/grpc_api.go b/cmd/layotto_multiple_api/helloworld/grpc_api.go
similarity index 100%
rename from pkg/integrate/api/helloworld/grpc_api.go
rename to cmd/layotto_multiple_api/helloworld/grpc_api.go
diff --git a/cmd/layotto_multiple_api/main.go b/cmd/layotto_multiple_api/main.go
index bdc07e9b3a..d6a31d28c9 100644
--- a/cmd/layotto_multiple_api/main.go
+++ b/cmd/layotto_multiple_api/main.go
@@ -19,9 +19,9 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	helloworld_api "mosn.io/layotto/cmd/layotto_multiple_api/helloworld"
 	"mosn.io/layotto/pkg/grpc/dapr"
 	"mosn.io/layotto/pkg/grpc/default_api"
-	helloworld_api "mosn.io/layotto/pkg/integrate/api/helloworld"
 	"os"
 	"strconv"
 	"time"
diff --git a/pkg/grpc/grpc_api.go b/pkg/grpc/grpc_api.go
index 09f31596fd..08aa1cb611 100644
--- a/pkg/grpc/grpc_api.go
+++ b/pkg/grpc/grpc_api.go
@@ -39,9 +39,7 @@ type GrpcAPI interface {
 }
 
 // NewGrpcAPI is the constructor of GrpcAPI
-type NewGrpcAPI func(
-	applicationContext *ApplicationContext,
-) GrpcAPI
+type NewGrpcAPI func(applicationContext *ApplicationContext) GrpcAPI
 
 type ApplicationContext struct {
 	AppId                 string

From 002807d039190c350aa773db91cc459d32c72587 Mon Sep 17 00:00:00 2001
From: seeflood <349895584@qq.com>
Date: Sat, 18 Dec 2021 13:47:11 +0800
Subject: [PATCH 4/8] improve ut

---
 pkg/actuator/info/endpoint.go      | 3 +++
 pkg/actuator/info/endpoint_test.go | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/pkg/actuator/info/endpoint.go b/pkg/actuator/info/endpoint.go
index 65d6f6424e..987c74524b 100644
--- a/pkg/actuator/info/endpoint.go
+++ b/pkg/actuator/info/endpoint.go
@@ -61,5 +61,8 @@ func AddInfoContributor(name string, c Contributor) {
 
 // AddInfoContributorFunc register info.Contributor.It's not concurrent-safe,so please invoke it ONLY in init method.
 func AddInfoContributorFunc(name string, f func() (interface{}, error)) {
+	if f == nil {
+		return
+	}
 	AddInfoContributor(name, ContributorAdapter(f))
 }
diff --git a/pkg/actuator/info/endpoint_test.go b/pkg/actuator/info/endpoint_test.go
index d04ed4ef78..c49dbd5861 100644
--- a/pkg/actuator/info/endpoint_test.go
+++ b/pkg/actuator/info/endpoint_test.go
@@ -38,6 +38,11 @@ func TestEndpoint_Handle(t *testing.T) {
 	assert.True(t, err == nil)
 	assert.True(t, len(handle) == 0)
 
+	AddInfoContributorFunc("test", nil)
+	handle, err = ep.Handle(context.Background(), nil)
+	assert.True(t, err == nil)
+	assert.True(t, len(handle) == 0)
+
 	AddInfoContributor("test", nil)
 	handle, err = ep.Handle(context.Background(), nil)
 	assert.True(t, err == nil)

From 371ffa69a06376a45ef0a5e92ef0556b8de8a677 Mon Sep 17 00:00:00 2001
From: seeflood <349895584@qq.com>
Date: Sat, 18 Dec 2021 13:55:11 +0800
Subject: [PATCH 5/8] modify codecov.yml

---
 codecov.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/codecov.yml b/codecov.yml
index 899a28af85..67592ca474 100644
--- a/codecov.yml
+++ b/codecov.yml
@@ -12,7 +12,7 @@ coverage:
 
 ignore:
   # Configure what to ignore.
-  - "pkg/mock"         # - Testing mock.
+  - "pkg/mock/**/*"         # - Testing mock.
   # Ignore non-deterministic methods and tests
   # codecov might report unexpected changes even if no code has been changed.
   # see https://community.codecov.com/t/reported-change-in-coverage-when-no-code-changes-made/1346
@@ -24,3 +24,4 @@ ignore:
   - "pkg/grpc/dapr/proto/runtime/v1"
   - "pkg/grpc/dapr/dapr_api_unimplement.go"
   - "pkg/wasm/watcher.go"
+  - "cmd/**/*"

From fbfdb5c6156dab1c6cf60ed30b2c650778d7b6a5 Mon Sep 17 00:00:00 2001
From: seeflood <349895584@qq.com>
Date: Tue, 21 Dec 2021 14:20:00 +0800
Subject: [PATCH 6/8] fix imports

---
 cmd/layotto_multiple_api/main.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/cmd/layotto_multiple_api/main.go b/cmd/layotto_multiple_api/main.go
index dffa9af00e..c857d9dc3e 100644
--- a/cmd/layotto_multiple_api/main.go
+++ b/cmd/layotto_multiple_api/main.go
@@ -19,6 +19,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"mosn.io/api"
 	helloworld_api "mosn.io/layotto/cmd/layotto_multiple_api/helloworld"
 	"mosn.io/layotto/pkg/grpc/dapr"
 	"mosn.io/layotto/pkg/grpc/default_api"
@@ -118,6 +119,7 @@ import (
 
 	"github.com/urfave/cli"
 	"google.golang.org/grpc"
+	"mosn.io/layotto/diagnostics"
 	_ "mosn.io/layotto/pkg/filter/network/tcpcopy"
 	"mosn.io/layotto/pkg/runtime"
 	"mosn.io/mosn/pkg/featuregate"

From dcb2a229fecb3e62d1a33434fe5f044fba10d0c1 Mon Sep 17 00:00:00 2001
From: seeflood <349895584@qq.com>
Date: Tue, 21 Dec 2021 14:41:53 +0800
Subject: [PATCH 7/8] downgrade go version in workflow configuration

---
 .github/workflows/github-actions.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/github-actions.yml b/.github/workflows/github-actions.yml
index 352d6b29e1..06ac6a554c 100644
--- a/.github/workflows/github-actions.yml
+++ b/.github/workflows/github-actions.yml
@@ -15,7 +15,7 @@ jobs:
       # If you want to matrix build , you can append the following list.
       matrix:
         go_version:
-          - 1.15
+          - 1.14.13
         os:
           - ubuntu-latest
 
@@ -76,7 +76,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.15
+          go-version: 1.14.13
 
       - name: Check out code
         uses: actions/checkout@v2

From 599230261588006acf3ed86e9ee9f2d605f2b559 Mon Sep 17 00:00:00 2001
From: seeflood <349895584@qq.com>
Date: Tue, 21 Dec 2021 18:10:12 +0800
Subject: [PATCH 8/8] add comments

---
 components/rpc/callback/callback.go           |  8 ++---
 .../rpc/invoker/mosn/channel/connpool.go      |  5 +++-
 .../rpc/invoker/mosn/channel/httpchannel.go   | 30 +++++++++++++++----
 .../rpc/invoker/mosn/channel/xchannel.go      |  7 ++++-
 components/rpc/invoker/mosn/mosninvoker.go    |  6 ++--
 components/rpc/types.go                       |  6 ++--
 6 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/components/rpc/callback/callback.go b/components/rpc/callback/callback.go
index 4e97d85bf9..863eb52251 100644
--- a/components/rpc/callback/callback.go
+++ b/components/rpc/callback/callback.go
@@ -57,7 +57,7 @@ var (
 	// to storage BeforeFactory
 	beforeInvokeRegistry = map[string]BeforeFactory{}
 	// to storage AfterFactory
-	afterInvokeRegistry  = map[string]AfterFactory{}
+	afterInvokeRegistry = map[string]AfterFactory{}
 )
 
 // NewCallback is created Callback
@@ -84,7 +84,7 @@ func (c *callback) AddBeforeInvoke(conf rpc.CallbackFunc) {
 	c.beforeInvoke = append(c.beforeInvoke, f.Create())
 }
 
-// AddAfterInvoke is add beforeInvoke into callback.afterInvoke
+// AddAfterInvoke is used to add beforeInvoke into callback.afterInvoke
 func (c *callback) AddAfterInvoke(conf rpc.CallbackFunc) {
 	f, ok := afterInvokeRegistry[conf.Name]
 	if !ok {
@@ -98,7 +98,7 @@ func (c *callback) AddAfterInvoke(conf rpc.CallbackFunc) {
 	c.afterInvoke = append(c.afterInvoke, f.Create())
 }
 
-// BeforeInvoke is get RPCRequest in callback.beforeInvoke
+// BeforeInvoke is used to invoke beforeInvoke callbacks
 func (c *callback) BeforeInvoke(request *rpc.RPCRequest) (*rpc.RPCRequest, error) {
 	var err error
 	for _, cb := range c.beforeInvoke {
@@ -109,7 +109,7 @@ func (c *callback) BeforeInvoke(request *rpc.RPCRequest) (*rpc.RPCRequest, error
 	return request, err
 }
 
-// AfterInvoke is get RPCResponse in callback.afterInvoke
+// AfterInvoke is used to invoke afterInvoke callbacks
 func (c *callback) AfterInvoke(response *rpc.RPCResponse) (*rpc.RPCResponse, error) {
 	var err error
 	for _, cb := range c.afterInvoke {
diff --git a/components/rpc/invoker/mosn/channel/connpool.go b/components/rpc/invoker/mosn/channel/connpool.go
index dcf163ea0a..3d4de6bde4 100644
--- a/components/rpc/invoker/mosn/channel/connpool.go
+++ b/components/rpc/invoker/mosn/channel/connpool.go
@@ -88,7 +88,6 @@ func newConnPool(
 	return p
 }
 
-
 // connPool is connected pool
 type connPool struct {
 	maxActive   int
@@ -131,6 +130,7 @@ func (p *connPool) Get(ctx context.Context) (*wrapConn, error) {
 	if p.stateFunc != nil {
 		wc.state = p.stateFunc()
 	}
+	// start a readloop gorountine to read and handle data
 	if p.onDataFunc != nil {
 		utils.GoWithRecover(func() {
 			p.readloop(wc)
@@ -171,6 +171,7 @@ func (p *connPool) readloop(c *wrapConn) {
 
 	c.buf = buffer.NewIoBuffer(defaultBufSize)
 	for {
+		// read data from connection
 		n, readErr := c.buf.ReadOnce(c)
 		if readErr != nil {
 			err = readErr
@@ -182,6 +183,8 @@ func (p *connPool) readloop(c *wrapConn) {
 		}
 
 		if n > 0 {
+			// handle data.
+			// it will delegate to hstate if it's constructed by httpchannel
 			if onDataErr := p.onDataFunc(c); onDataErr != nil {
 				err = onDataErr
 				log.DefaultLogger.Errorf("[runtime][rpc]connpool onData err: %s", onDataErr.Error())
diff --git a/components/rpc/invoker/mosn/channel/httpchannel.go b/components/rpc/invoker/mosn/channel/httpchannel.go
index c3310688bf..c2745fe543 100644
--- a/components/rpc/invoker/mosn/channel/httpchannel.go
+++ b/components/rpc/invoker/mosn/channel/httpchannel.go
@@ -36,8 +36,11 @@ func init() {
 	RegistChannel("http", newHttpChannel)
 }
 
+// hstate is a pipe for readloop goroutine to communicate with request goroutine
 type hstate struct {
+	// request goroutine will read data from it
 	reader net.Conn
+	// readloop goroutine will write data to it
 	writer net.Conn
 }
 
@@ -60,11 +63,12 @@ type httpChannel struct {
 	pool *connPool
 }
 
-// newHttpChannel is create rpc.Channel by ChannelConfig
+// newHttpChannel is used to create rpc.Channel according to ChannelConfig
 func newHttpChannel(config ChannelConfig) (rpc.Channel, error) {
 	hc := &httpChannel{}
 	hc.pool = newConnPool(
 		config.Size,
+		// dialFunc
 		func() (net.Conn, error) {
 			local, remote := net.Pipe()
 			localTcpConn := &fakeTcpConn{c: local}
@@ -72,8 +76,17 @@ func newHttpChannel(config ChannelConfig) (rpc.Channel, error) {
 			if err := acceptFunc(remoteTcpConn, config.Listener); err != nil {
 				return nil, err
 			}
+			// the goroutine model is:
+			// request goroutine --->  localTcpConn ---> mosn
+			//		^										|
+			//		|										|
+			//		|										|
+			// 		hstate <-- readloop goroutine 	<------
 			return localTcpConn, nil
-		}, func() interface{} {
+		},
+		// stateFunc
+		func() interface{} {
+			// hstate is a pipe for readloop goroutine to communicate with request goroutine
 			s := &hstate{}
 			s.reader, s.writer = net.Pipe()
 			return s
@@ -84,17 +97,21 @@ func newHttpChannel(config ChannelConfig) (rpc.Channel, error) {
 	return hc, nil
 }
 
-// Do is handle RPCRequest to RPCResponse
+// Do is used to handle RPCRequest and return RPCResponse
 func (h *httpChannel) Do(req *rpc.RPCRequest) (*rpc.RPCResponse, error) {
+	// 1. context.WithTimeout
 	timeout := time.Duration(req.Timeout) * time.Millisecond
 	ctx, cancel := context.WithTimeout(req.Ctx, timeout)
 	defer cancel()
 
+	// 2. get a fake connection with mosn
+	// The pool will start a readloop gorountine,
+	// which aims to read data from mosn and then write data to the hstate.writer
 	conn, err := h.pool.Get(ctx)
 	if err != nil {
 		return nil, err
 	}
-
+	// 3. set deadline before write data to this connection
 	hstate := conn.state.(*hstate)
 	deadline, _ := ctx.Deadline()
 	if err = conn.SetWriteDeadline(deadline); err != nil {
@@ -102,7 +119,7 @@ func (h *httpChannel) Do(req *rpc.RPCRequest) (*rpc.RPCResponse, error) {
 		h.pool.Put(conn, true)
 		return nil, common.Error(common.UnavailebleCode, err.Error())
 	}
-
+	// 4. write data to this fake connection
 	httpReq := h.constructReq(req)
 	defer fasthttp.ReleaseRequest(httpReq)
 
@@ -112,6 +129,7 @@ func (h *httpChannel) Do(req *rpc.RPCRequest) (*rpc.RPCResponse, error) {
 		return nil, common.Error(common.UnavailebleCode, err.Error())
 	}
 
+	// 5. read response data and parse it into fasthttp.Response
 	httpResp := &fasthttp.Response{}
 	hstate.reader.SetReadDeadline(deadline)
 
@@ -121,6 +139,8 @@ func (h *httpChannel) Do(req *rpc.RPCRequest) (*rpc.RPCResponse, error) {
 		return nil, common.Error(common.UnavailebleCode, err.Error())
 	}
 	h.pool.Put(conn, false)
+
+	// 6. convert result to rpc.RPCResponse,which is the response of rpc invoker
 	body := httpResp.Body()
 	if httpResp.StatusCode() != http.StatusOK {
 		return nil, common.Errorf(common.UnavailebleCode, "http response code %d, body: %s", httpResp.StatusCode(), string(body))
diff --git a/components/rpc/invoker/mosn/channel/xchannel.go b/components/rpc/invoker/mosn/channel/xchannel.go
index 36c17f9ba5..839628d51e 100644
--- a/components/rpc/invoker/mosn/channel/xchannel.go
+++ b/components/rpc/invoker/mosn/channel/xchannel.go
@@ -51,6 +51,7 @@ func newXChannel(config ChannelConfig) (rpc.Channel, error) {
 	m := &xChannel{proto: proto}
 	m.pool = newConnPool(
 		config.Size,
+		// dialFunc
 		func() (net.Conn, error) {
 			local, remote := net.Pipe()
 			localTcpConn := &fakeTcpConn{c: local}
@@ -60,6 +61,7 @@ func newXChannel(config ChannelConfig) (rpc.Channel, error) {
 			}
 			return localTcpConn, nil
 		},
+		// stateFunc
 		func() interface{} {
 			return &xstate{calls: map[uint32]chan call{}}
 		},
@@ -90,10 +92,12 @@ type xChannel struct {
 
 // Do is handle RPCRequest to RPCResponse
 func (m *xChannel) Do(req *rpc.RPCRequest) (*rpc.RPCResponse, error) {
+	// 1. context.WithTimeout
 	timeout := time.Duration(req.Timeout) * time.Millisecond
 	ctx, cancel := context.WithTimeout(req.Ctx, timeout)
 	defer cancel()
 
+	// 2. get fake connection with mosn
 	conn, err := m.pool.Get(ctx)
 	if err != nil {
 		return nil, err
@@ -101,7 +105,7 @@ func (m *xChannel) Do(req *rpc.RPCRequest) (*rpc.RPCResponse, error) {
 
 	xstate := conn.state.(*xstate)
 
-	// encode request
+	// 3. encode request
 	frame := m.proto.ToFrame(req)
 	id := atomic.AddUint32(&xstate.reqid, 1)
 	frame.SetRequestId(uint64(id))
@@ -131,6 +135,7 @@ func (m *xChannel) Do(req *rpc.RPCRequest) (*rpc.RPCResponse, error) {
 	}
 	m.pool.Put(conn, false)
 
+	// read response and decode it
 	select {
 	case res := <-callChan:
 		if res.err != nil {
diff --git a/components/rpc/invoker/mosn/mosninvoker.go b/components/rpc/invoker/mosn/mosninvoker.go
index 18ac934459..6a1c3b1d23 100644
--- a/components/rpc/invoker/mosn/mosninvoker.go
+++ b/components/rpc/invoker/mosn/mosninvoker.go
@@ -89,24 +89,26 @@ func (m *mosnInvoker) Invoke(ctx context.Context, req *rpc.RPCRequest) (resp *rp
 		}
 	}()
 
+	// 1. validate request
 	if req.Timeout == 0 {
 		req.Timeout = 3000
 	}
 	req.Ctx = ctx
 	log.DefaultLogger.Debugf("[runtime][rpc]request %+v", req)
+	// 2. beforeInvoke callback
 	req, err = m.cb.BeforeInvoke(req)
 	if err != nil {
 		log.DefaultLogger.Errorf("[runtime][rpc]before filter error %s", err.Error())
 		return nil, err
 	}
-
+	// 3. do invocation
 	resp, err = m.channel.Do(req)
 	if err != nil {
 		log.DefaultLogger.Errorf("[runtime][rpc]error %s", err.Error())
 		return nil, err
 	}
-
 	resp.Ctx = req.Ctx
+	// 4. afterInvoke callback
 	resp, err = m.cb.AfterInvoke(resp)
 	if err != nil {
 		log.DefaultLogger.Errorf("[runtime][rpc]after filter error %s", err.Error())
diff --git a/components/rpc/types.go b/components/rpc/types.go
index abb8644b75..150b28fb23 100644
--- a/components/rpc/types.go
+++ b/components/rpc/types.go
@@ -53,7 +53,7 @@ func (r RPCHeader) Get(key string) string {
 // RPCRequest is request info
 type RPCRequest struct {
 	// context
-	Ctx         context.Context
+	Ctx context.Context
 	// request id
 	Id          string
 	Timeout     int32
@@ -88,9 +88,9 @@ type Callback interface {
 	// AddAfterInvoke is add AfterInvoke func
 	AddAfterInvoke(CallbackFunc)
 
-	// BeforeInvoke is get BeforeInvoke by RPCRequest
+	// BeforeInvoke is used to invoke beforeInvoke callbacks
 	BeforeInvoke(*RPCRequest) (*RPCRequest, error)
-	// AfterInvoke is get AfterInvoke by RPCRequest
+	// AfterInvoke is used to invoke afterInvoke callbacks
 	AfterInvoke(*RPCResponse) (*RPCResponse, error)
 }