net/internal/socktest: add missing support for AcceptEx

Change-Id: I37faedc6fa316fffac80093b01e15429995b0f5b
Reviewed-on: https://go-review.googlesource.com/19705Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/net/internal/socktest/switch.go

@@ -121,7 +121,7 @@ const (
 	FilterSocket        FilterType = iota // for Socket
 	FilterConnect                         // for Connect or ConnectEx
 	FilterListen                          // for Listen
-	FilterAccept                          // for Accept or Accept4
+	FilterAccept                          // for Accept, Accept4 or AcceptEx
 	FilterGetsockoptInt                   // for GetsockoptInt
 	FilterClose                           // for Close or Closesocket
 )

src/net/internal/socktest/sys_windows.go

@@ -154,3 +154,33 @@ func (sw *Switch) Listen(s syscall.Handle, backlog int) (err error) {
 	sw.stats.getLocked(so.Cookie).Listened++
 	return nil
 }
+
+// AcceptEx wraps syscall.AcceptEx.
+func (sw *Switch) AcceptEx(ls syscall.Handle, as syscall.Handle, b *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, rcvd *uint32, overlapped *syscall.Overlapped) error {
+	so := sw.sockso(ls)
+	if so == nil {
+		return syscall.AcceptEx(ls, as, b, rxdatalen, laddrlen, raddrlen, rcvd, overlapped)
+	}
+	sw.fmu.RLock()
+	f, _ := sw.fltab[FilterAccept]
+	sw.fmu.RUnlock()
+
+	af, err := f.apply(so)
+	if err != nil {
+		return err
+	}
+	so.Err = syscall.AcceptEx(ls, as, b, rxdatalen, laddrlen, raddrlen, rcvd, overlapped)
+	if err = af.apply(so); err != nil {
+		return err
+	}
+
+	sw.smu.Lock()
+	defer sw.smu.Unlock()
+	if so.Err != nil {
+		sw.stats.getLocked(so.Cookie).AcceptFailed++
+		return so.Err
+	}
+	nso := sw.addLocked(as, so.Cookie.Family(), so.Cookie.Type(), so.Cookie.Protocol())
+	sw.stats.getLocked(nso.Cookie).Accepted++
+	return nil
+}