Allow late connecting

client/client.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net"
 	"sync"
+	"time"
 
 	. "github.com/tendermint/go-common"
 	"github.com/tendermint/tmsp/types"
@@ -25,47 +26,70 @@ type Client struct {
 	QuitService
 	sync.Mutex // [EB]: is this even used?
 
-	reqQueue   chan *ReqRes
-	flushTimer *ThrottleTimer
+	reqQueue    chan *ReqRes
+	flushTimer  *ThrottleTimer
+	mustConnect bool
 
-	mtx       sync.Mutex
-	addr      string
-	conn      net.Conn
-	bufWriter *bufio.Writer
-	err       error
-	reqSent   *list.List
-	resCb     func(*types.Request, *types.Response) // listens to all callbacks
+	mtx     sync.Mutex
+	addr    string
+	conn    net.Conn
+	err     error
+	reqSent *list.List
+	resCb   func(*types.Request, *types.Response) // listens to all callbacks
 }
 
-func NewClient(addr string) (*Client, error) {
-	conn, err := Connect(addr)
-	if err != nil {
-		return nil, err
-	}
+func NewClient(addr string, mustConnect bool) (*Client, error) {
 	cli := &Client{
-		reqQueue:   make(chan *ReqRes, reqQueueSize),
-		flushTimer: NewThrottleTimer("Client", flushThrottleMS),
+		reqQueue:    make(chan *ReqRes, reqQueueSize),
+		flushTimer:  NewThrottleTimer("Client", flushThrottleMS),
+		mustConnect: mustConnect,
 
-		conn:      conn,
-		bufWriter: bufio.NewWriter(conn),
-		reqSent:   list.New(),
-		resCb:     nil,
+		addr:    addr,
+		reqSent: list.New(),
+		resCb:   nil,
 	}
 	cli.QuitService = *NewQuitService(nil, "Client", cli)
-	cli.Start() // Just start it, it's confusing for callers to remember to start.
-	return cli, nil
+	_, err := cli.Start() // Just start it, it's confusing for callers to remember to start.
+	if mustConnect {
+		return nil, err
+	} else {
+		return cli, nil
+	}
 }
 
-func (cli *Client) OnStart() error {
+func (cli *Client) OnStart() (err error) {
 	cli.QuitService.OnStart()
-	go cli.sendRequestsRoutine()
-	go cli.recvResponseRoutine()
-	return nil
+	doneCh := make(chan struct{})
+	go func() {
+	RETRY_LOOP:
+		for {
+			conn, err_ := Connect(cli.addr)
+			if err_ != nil {
+				if cli.mustConnect {
+					err = err_ // OnStart() will return this.
+					close(doneCh)
+					return
+				} else {
+					fmt.Printf("tmsp.Client failed to connect to %v.  Retrying...\n", cli.addr)
+					time.Sleep(time.Second * 3)
+					continue RETRY_LOOP
+				}
+			}
+			go cli.sendRequestsRoutine(conn)
+			go cli.recvResponseRoutine(conn)
+			close(doneCh) // OnStart() will return no error.
+			return
+		}
+	}()
+	<-doneCh
+	return // err
 }
 
 func (cli *Client) OnStop() {
 	cli.QuitService.OnStop()
-	cli.conn.Close()
+	if cli.conn != nil {
+		cli.conn.Close()
+	}
 }
 
 // Set listener for all responses
@@ -78,7 +102,7 @@ func (cli *Client) SetResponseCallback(resCb Callback) {
 
 func (cli *Client) StopForError(err error) {
 	cli.mtx.Lock()
-	// log.Error("Stopping Client for error.", "error", err)
+	fmt.Printf("Stopping tmsp.Client for error: %v\n", err.Error())
 	if cli.err == nil {
 		cli.err = err
 	}
@@ -94,7 +118,8 @@ func (cli *Client) Error() error {
 
 //----------------------------------------
 
-func (cli *Client) sendRequestsRoutine() {
+func (cli *Client) sendRequestsRoutine(conn net.Conn) {
+	w := bufio.NewWriter(conn)
 	for {
 		select {
 		case <-cli.flushTimer.Ch:
@@ -107,14 +132,14 @@ func (cli *Client) sendRequestsRoutine() {
 			return
 		case reqres := <-cli.reqQueue:
 			cli.willSendReq(reqres)
-			err := types.WriteMessage(reqres.Request, cli.bufWriter)
+			err := types.WriteMessage(reqres.Request, w)
 			if err != nil {
 				cli.StopForError(err)
 				return
 			}
 			// log.Debug("Sent request", "requestType", reflect.TypeOf(reqres.Request), "request", reqres.Request)
 			if reqres.Request.Type == types.MessageType_Flush {
-				err = cli.bufWriter.Flush()
+				err = w.Flush()
 				if err != nil {
 					cli.StopForError(err)
 					return
@@ -124,8 +149,8 @@ func (cli *Client) sendRequestsRoutine() {
 	}
 }
 
-func (cli *Client) recvResponseRoutine() {
-	r := bufio.NewReader(cli.conn) // Buffer reads
+func (cli *Client) recvResponseRoutine(conn net.Conn) {
+	r := bufio.NewReader(conn) // Buffer reads
 	for {
 		var res = &types.Response{}
 		err := types.ReadMessage(r, res)

tests/test_counter.go

@@ -70,7 +70,7 @@ func startApp() *process.Process {
 
 func startClient() *tmspcli.Client {
 	// Start client
-	client, err := tmspcli.NewClient("tcp://127.0.0.1:46658")
+	client, err := tmspcli.NewClient("tcp://127.0.0.1:46658", true)
 	if err != nil {
 		panic("connecting to counter_app: " + err.Error())
 	}