Add Connect and Disconnect functionality

GODRIVER-285

Change-Id: I1d2eae1cc94a93c0664665541b12682131a49018

core/connection/connection.go

@@ -50,6 +50,14 @@ type Dialer interface {
 	DialContext(ctx context.Context, network, address string) (net.Conn, error)
 }
 
+// DialerFunc is a type implemented by functions that can be used as a Dialer.
+type DialerFunc func(ctx context.Context, network, address string) (net.Conn, error)
+
+// DialContext implements the Dialer interface.
+func (df DialerFunc) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+	return df(ctx, network, address)
+}
+
 // DefaultDialer is the Dialer implementation that is used by this package. Changing this
 // will also change the Dialer used for this package. This should only be changed why all
 // of the connections being made need to use a different Dialer. Most of the time, using a

core/connection/connection_test.go

@@ -7,26 +7,83 @@
 package connection
 
 import (
+	"context"
 	"net"
+	"sync"
 	"testing"
 )
 
 // bootstrapConnection creates a listener that will listen for a single connection
 // on the return address. The user provided run function will be called with the accepted
 // connection. The user is responsible for closing the connection.
-func bootstrapConnection(t *testing.T, run func(net.Conn)) net.Addr {
-	l, err := net.Listen("tcp", ":0")
+func bootstrapConnections(t *testing.T, num int, run func(net.Conn)) net.Addr {
+	l, err := net.Listen("tcp", "localhost:0")
 	if err != nil {
 		t.Errorf("Could not set up a listener: %v", err)
 		t.FailNow()
 	}
 	go func() {
-		c, err := l.Accept()
-		if err != nil {
-			t.Errorf("Could not accept a connection: %v", err)
+		for i := 0; i < num; i++ {
+			c, err := l.Accept()
+			if err != nil {
+				t.Errorf("Could not accept a connection: %v", err)
+			}
+			go run(c)
 		}
 		_ = l.Close()
-		run(c)
 	}()
 	return l.Addr()
 }
+
+type netconn struct {
+	net.Conn
+	closed chan struct{}
+	d      *dialer
+}
+
+func (nc *netconn) Close() error {
+	nc.closed <- struct{}{}
+	nc.d.connclosed(nc)
+	return nc.Conn.Close()
+}
+
+type dialer struct {
+	Dialer
+	opened map[*netconn]struct{}
+	closed map[*netconn]struct{}
+	sync.Mutex
+}
+
+func newdialer(d Dialer) *dialer {
+	return &dialer{Dialer: d, opened: make(map[*netconn]struct{}), closed: make(map[*netconn]struct{})}
+}
+
+func (d *dialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+	d.Lock()
+	defer d.Unlock()
+	c, err := d.Dialer.DialContext(ctx, network, address)
+	if err != nil {
+		return nil, err
+	}
+	nc := &netconn{Conn: c, closed: make(chan struct{}, 1), d: d}
+	d.opened[nc] = struct{}{}
+	return nc, nil
+}
+
+func (d *dialer) connclosed(nc *netconn) {
+	d.Lock()
+	defer d.Unlock()
+	d.closed[nc] = struct{}{}
+}
+
+func (d *dialer) lenopened() int {
+	d.Lock()
+	defer d.Unlock()
+	return len(d.opened)
+}
+
+func (d *dialer) lenclosed() int {
+	d.Lock()
+	defer d.Unlock()
+	return len(d.closed)
+}

core/connection/error.go

@@ -34,3 +34,8 @@ type NetworkError struct {
 func (ne NetworkError) Error() string {
 	return fmt.Sprintf("connection(%s): %s", ne.ConnectionID, ne.Wrapped.Error())
 }
+
+// PoolError is an error returned from a Pool method.
+type PoolError string
+
+func (pe PoolError) Error() string { return string(pe) }