Merge pull request ethereum#134 from nonsense/p2p-sim-tcp-adapter

p2p/simulations: tcp pipe

p2p/simulations/adapters/inproc.go

@@ -72,6 +72,14 @@ func NewSocketAdapter(services map[string]ServiceFunc) *SimAdapter {
 	}
 }
 
+func NewTCPAdapter(services map[string]ServiceFunc) *SimAdapter {
+	return &SimAdapter{
+		pipe:     tcpPipe,
+		nodes:    make(map[discover.NodeID]*SimNode),
+		services: services,
+	}
+}
+
 // Name returns the name of the adapter for logging purposes
 func (s *SimAdapter) Name() string {
 	return "sim-adapter"
@@ -403,3 +411,58 @@ func netPipe() (net.Conn, net.Conn, error) {
 	p1, p2 := net.Pipe()
 	return p1, p2, nil
 }
+
+// tcpPipe creates an in process full duplex pipe based on a localhost TCP socket
+func tcpPipe() (net.Conn, net.Conn, error) {
+	type result struct {
+		conn net.Conn
+		err  error
+	}
+
+	cl := make(chan result)
+	cd := make(chan result)
+
+	start := make(chan net.Addr)
+
+	go func(res chan result, start chan net.Addr) {
+		// resolve
+		addr, err := net.ResolveTCPAddr("tcp", "localhost:0")
+		if err != nil {
+			res <- result{err: err}
+			return
+		}
+		// listen
+		l, err := net.ListenTCP("tcp", addr)
+		if err != nil {
+			res <- result{err: err}
+			return
+		}
+		start <- l.Addr()
+		c, err := l.AcceptTCP()
+		if err != nil {
+			res <- result{err: err}
+			return
+		}
+		res <- result{conn: c}
+	}(cl, start)
+
+	go func(res chan result, start chan net.Addr) {
+		addr := <-start
+		c, err := net.DialTCP("tcp", nil, addr.(*net.TCPAddr))
+		if err != nil {
+			res <- result{err: err}
+			return
+		}
+		res <- result{conn: c}
+	}(cd, start)
+
+	a := <-cl
+	if a.err != nil {
+		return nil, nil, a.err
+	}
+	b := <-cd
+	if b.err != nil {
+		return nil, nil, b.err
+	}
+	return a.conn, b.conn, nil
+}