updating for robustness

client.go

@@ -7,7 +7,6 @@ import "crypto/tls"
 import "encoding/json"
 import "errors"
 import "fmt"
-import "io"
 import "net"
 import "net/http"
 import "sync"
@@ -16,7 +15,9 @@ import "time"
 
 //import "github.com/google/uuid"
 import "google.golang.org/grpc"
+import "google.golang.org/grpc/codes"
 import "google.golang.org/grpc/credentials/insecure"
+import "google.golang.org/grpc/status"
 
 const PTC_LIMIT = 8192
 
@@ -94,8 +95,6 @@ type ClientRoute struct {
 	ptc_mtx        sync.Mutex
 	ptc_map        ClientPeerConnMap
 	ptc_cancel_map ClientPeerCancelFuncMap
-	//ptc_limit      int
-	//ptc_last_id    uint32
 	ptc_wg sync.WaitGroup
 
 	stop_req atomic.Bool
@@ -136,10 +135,8 @@ func NewClientRoute(cts *ServerConn, id uint32, addr *net.TCPAddr, proto ROUTE_P
 
 	r.cts = cts
 	r.id = id
-	//r.ptc_limit = PTC_LIMIT
 	r.ptc_map = make(ClientPeerConnMap)
 	r.ptc_cancel_map = make(ClientPeerCancelFuncMap)
-	//r.ptc_last_id = 0
 	r.proto = proto
 	r.peer_addr = addr
 	r.stop_req.Store(false)
@@ -149,10 +146,18 @@ func NewClientRoute(cts *ServerConn, id uint32, addr *net.TCPAddr, proto ROUTE_P
 }
 
 func (r *ClientRoute) RunTask(wg *sync.WaitGroup) {
+	var err error
+
 	// this task on the route object isn't actually necessary.
 	// most useful works are triggered by ReportEvent() and done by ConnectToPeer()
 	defer wg.Done()
 
+	err = r.cts.psc.Send(MakeRouteStartPacket(r.id, r.proto, r.peer_addr.String()))
+	if err != nil {
+		//return fmt.Errorf("unable to send route-start packet - %s", err.Error())
+		goto done;
+	}
+
 main_loop:
 	for {
 		select {
@@ -161,7 +166,12 @@ main_loop:
 		}
 	}
 
+done:
+	r.ReqStop()
 	r.ptc_wg.Wait() // wait for all peer tasks are finished
+
+	r.cts.psc.Send(MakeRouteStopPacket(r.id, r.proto, r.peer_addr.String()))
+	r.cts.RemoveClientRoute(r)
 fmt.Printf ("*** End fo Client Roue Task\n")
 }
 
@@ -171,7 +181,6 @@ func (r *ClientRoute) ReqStop() {
 		for _, ptc = range r.ptc_map {
 			ptc.ReqStop()
 		}
-
 		r.stop_chan <- true
 	}
 fmt.Printf ("*** Sent stop request to Route..\n")
@@ -404,7 +413,6 @@ func (cts *ServerConn) AddClientRoutes (peer_addrs []string) error {
 	var v string
 	var addr *net.TCPAddr
 	var proto ROUTE_PROTO
-	var r *ClientRoute
 	var err error
 
 	for i, v = range peer_addrs {
@@ -425,58 +433,37 @@ func (cts *ServerConn) AddClientRoutes (peer_addrs []string) error {
 		}
 	}
 
-// TODO: mutex protection
-	for _, r = range cts.route_map  {
-		err = cts.psc.Send(MakeRouteStartPacket(r.id, r.proto, addr.String()))
-		if err != nil {
-// TODO: remove all routes???
-			return fmt.Errorf("unable to send route-start packet - %s", err.Error())
-		}
-	}
-
 	return nil
 }
 
-func (cts *ServerConn) RemoveClientRoutes () {
+func (cts *ServerConn) disconnect_from_server() {
-	var r *ClientRoute
+	if cts.conn != nil {
-	var id uint32
+		var r* ClientRoute
 
 		cts.route_mtx.Lock()
 		for _, r = range cts.route_map {
 			r.ReqStop()
 		}
-
-	for id, r = range cts.route_map {
-		delete(cts.route_map, id)
-	}
-
-	cts.route_map = make(ClientRouteMap)
 		cts.route_mtx.Unlock()
 
-// TODO: mutex protection?
+		cts.conn.Close()
-	for _, r = range cts.route_map  {
+		// don't reset cts.conn to nil here
-		cts.psc.Send(MakeRouteStopPacket(r.id, r.proto, r.peer_addr.String()))
+		// if this function is called from RunTask()
+		// for reconnection, it will be set to a new value
+		// immediately after the start_over lable in it.
+		// if it's called from ReqStop(), we don't really
+		// need to care about it.
 	}
 }
 
 func (cts *ServerConn) ReqStop() {
 	if cts.stop_req.CompareAndSwap(false, true) {
-		var r *ClientRoute
+		cts.disconnect_from_server()
-
-		cts.route_mtx.Lock()
-		for _, r = range cts.route_map  {
-			cts.psc.Send(MakeRouteStopPacket(r.id, r.proto, r.peer_addr.String())) // don't care about failure
-			r.ReqStop()
-		}
-		cts.route_mtx.Unlock()
-
 		cts.stop_chan <- true
 	}
 }
 
 func (cts *ServerConn) RunTask(wg *sync.WaitGroup) {
-	var conn *grpc.ClientConn = nil
-	var hdc HoduClient
 	var psc PacketStreamClient
 	var slpctx context.Context
 	var c_seed Seed
@@ -485,23 +472,25 @@ func (cts *ServerConn) RunTask(wg *sync.WaitGroup) {
 
 	defer wg.Done() // arrange to call at the end of this function
 
-// TODO: HANDLE connection timeout..
-	//	ctx, _/*cancel*/ := context.WithTimeout(context.Background(), time.Second)
 start_over:
+	cts.cli.log.Write ("", LOG_DEBUG, "Total number of server connections = %d", len(cts.cli.cts_map))
+
 	cts.cli.log.Write("", LOG_INFO, "Connecting to server %s", cts.saddr.String())
-	conn, err = grpc.NewClient(cts.saddr.String(), grpc.WithTransportCredentials(insecure.NewCredentials()))
+	cts.conn, err = grpc.NewClient(cts.saddr.String(), grpc.WithTransportCredentials(insecure.NewCredentials()))
 	if err != nil {
-		cts.cli.log.Write("", LOG_ERROR, "Failed to connect to server %s - %s", cts.saddr.String(), err.Error())
+		cts.cli.log.Write("", LOG_ERROR, "Failed to make client to server %s - %s", cts.saddr.String(), err.Error())
 		goto reconnect_to_server
 	}
+	cts.hdc = NewHoduClient(cts.conn)
 
-	hdc = NewHoduClient(conn)
+// TODO: HANDLE connection timeout.. may have to run GetSeed or PacketStream in anther goroutnine
+//	ctx, _/*cancel*/ := context.WithTimeout(context.Background(), time.Second)
 
 	// seed exchange is for furture expansion of the protocol
 	// there is nothing to do much about it for now.
 	c_seed.Version = HODU_VERSION
 	c_seed.Flags = 0
-	s_seed, err = hdc.GetSeed(cts.cli.ctx, &c_seed)
+	s_seed, err = cts.hdc.GetSeed(cts.cli.ctx, &c_seed)
 	if err != nil {
 		cts.cli.log.Write("", LOG_ERROR, "Failed to get seed from server %s - %s", cts.saddr.String(), err.Error())
 		goto reconnect_to_server
@@ -509,7 +498,9 @@ start_over:
 	cts.s_seed = *s_seed
 	cts.c_seed = c_seed
 
-	psc, err = hdc.PacketStream(cts.cli.ctx)
+	cts.cli.log.Write("", LOG_INFO, "Got seed from server %s - ver=%#x", cts.saddr.String(), cts.s_seed.Version)
+
+	psc, err = cts.hdc.PacketStream(cts.cli.ctx)
 	if err != nil {
 		cts.cli.log.Write("", LOG_ERROR, "Failed to get packet stream from server %s - %s", cts.saddr.String(), err.Error())
 		goto reconnect_to_server
@@ -517,9 +508,6 @@ start_over:
 
 	cts.cli.log.Write("", LOG_INFO, "Got packet stream from server %s", cts.saddr.String())
 
-	cts.conn = conn
-	cts.hdc = hdc
-	//cts.psc = &GuardedPacketStreamClient{psc: psc}
 	cts.psc = &GuardedPacketStreamClient{Hodu_PacketStreamClient: psc}
 
 	// the connection structure to a server is ready.
@@ -550,7 +538,7 @@ fmt.Printf("context doine... error - %s\n", cts.cli.ctx.Err().Error())
 
 		pkt, err = psc.Recv()
 		if err != nil {
-			if errors.Is(err, io.EOF) {
+			if status.Code(err) == codes.Canceled || errors.Is(err, net.ErrClosed) {
 				goto reconnect_to_server
 			} else {
 				cts.cli.log.Write("", LOG_INFO, "Failed to receive packet form server %s - %s", cts.saddr.String(), err.Error())
@@ -660,14 +648,16 @@ fmt.Printf("context doine... error - %s\n", cts.cli.ctx.Err().Error())
 
 done:
 	cts.cli.log.Write("", LOG_INFO, "Disconnected from server %s", cts.saddr.String())
-	cts.RemoveClientRoutes()
+	//cts.RemoveClientRoutes()
-	if conn != nil { conn.Close() }
+	cts.ReqStop()
+wait_for_termination:
 	cts.route_wg.Wait() // wait until all route tasks are finished
+	cts.cli.RemoveServerConn(cts)
 	return
 
 reconnect_to_server:
-	cts.RemoveClientRoutes()
+	cts.disconnect_from_server()
-	if conn != nil { conn.Close() }
+
 	// wait for 2 seconds
 	slpctx, _ = context.WithTimeout(cts.cli.ctx, 2 * time.Second)
 	select {
@@ -675,7 +665,9 @@ reconnect_to_server:
 			fmt.Printf("context doine... error - %s\n", cts.cli.ctx.Err().Error())
 			goto done
 		case <-cts.stop_chan:
-			goto done
+			// this signal indicates that ReqStop() has been called
+			// so jumt to the waiting label
+			goto wait_for_termination
 		case <- slpctx.Done():
 			// do nothing
 	}
@@ -700,35 +692,12 @@ func (cts *ServerConn) ReportEvent (route_id uint32, pts_id uint32, event_type P
 
 func (r *ClientRoute) AddNewClientPeerConn (c *net.TCPConn, pts_id uint32) (*ClientPeerConn, error) {
 	var ptc *ClientPeerConn
-	//var ok bool
-	//var start_id uint32
 
 	r.ptc_mtx.Lock()
 	defer r.ptc_mtx.Unlock()
 
-/*
-	if len(r.ptc_map) >= r.ptc_limit {
-		return nil, fmt.Errorf("peer-to-client connection table full")
-	}
-
-	start_id = r.ptc_last_id
-	for {
-		_, ok = r.ptc_map[r.ptc_last_id]
-		if !ok {
-			break
-		}
-		r.ptc_last_id++
-		if r.ptc_last_id == start_id {
-			// unlikely to happen but it cycled through the whole range.
-			return nil, fmt.Errorf("failed to assign peer-to-table connection id")
-		}
-	}
-
-	ptc = NewClientPeerConn(r, c, r.ptc_last_id)
-*/
 	ptc = NewClientPeerConn(r, c, pts_id)
 	r.ptc_map[ptc.conn_id] = ptc
-	//r.ptc_last_id++
 
 	return ptc, nil
 }
@@ -777,7 +746,7 @@ fmt.Printf ("ADD total servers %d\n", len(c.cts_map))
 func (c *Client) RemoveServerConn(cts *ServerConn) {
 	c.cts_mtx.Lock()
 	delete(c.cts_map, cts.saddr)
-fmt.Printf ("REMOVE total servers %d\n", len(c.cts_map))
+fmt.Printf ("REMOVEDDDDDD CONNECTION FROM %s total servers %d\n", cts.saddr, len(c.cts_map))
 	c.cts_mtx.Unlock()
 }
 
@@ -793,7 +762,6 @@ func (c *Client) ReqStop() {
 			cts.ReqStop()
 		}
 
-		// TODO: notify the server.. send term command???
 		c.stop_chan <- true
 		c.ctx_cancel()
 	}

server.go

@@ -18,7 +18,6 @@ import "google.golang.org/grpc/peer"
 import "google.golang.org/grpc/stats"
 
 const PTS_LIMIT = 8192
-//const CTS_LIMIT = 2048
 
 type ClientConnMap = map[net.Addr]*ClientConn
 type ServerPeerConnMap = map[uint32]*ServerPeerConn