1 files changed, 12 insertions, 59 deletions

diff --git a/libgo/go/net/fd_plan9.go b/libgo/go/net/fd_plan9.go
index cec8860..7533232 100644
--- a/libgo/go/net/fd_plan9.go
+++ b/libgo/go/net/fd_plan9.go
@@ -1,4 +1,4 @@
-// Copyright 2009 The Go Authors.  All rights reserved.
+// Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
@@ -32,12 +32,6 @@ func sysInit() {
 	netdir = "/net"
 }
 
-func dial(net string, ra Addr, dialer func(time.Time) (Conn, error), deadline time.Time) (Conn, error) {
-	// On plan9, use the relatively inefficient
-	// goroutine-racing implementation.
-	return dialChannel(net, ra, dialer, deadline)
-}
-
 func newFD(net, name string, ctl, data *os.File, laddr, raddr Addr) (*netFD, error) {
 	return &netFD{net: net, n: name, dir: netdir + "/" + net + "/" + name, ctl: ctl, data: data, laddr: laddr, raddr: raddr}, nil
 }
@@ -74,55 +68,6 @@ func (fd *netFD) destroy() {
 	fd.data = nil
 }
 
-// Add a reference to this fd.
-// Returns an error if the fd cannot be used.
-func (fd *netFD) incref() error {
-	if !fd.fdmu.Incref() {
-		return errClosing
-	}
-	return nil
-}
-
-// Remove a reference to this FD and close if we've been asked to do so
-// (and there are no references left).
-func (fd *netFD) decref() {
-	if fd.fdmu.Decref() {
-		fd.destroy()
-	}
-}
-
-// Add a reference to this fd and lock for reading.
-// Returns an error if the fd cannot be used.
-func (fd *netFD) readLock() error {
-	if !fd.fdmu.RWLock(true) {
-		return errClosing
-	}
-	return nil
-}
-
-// Unlock for reading and remove a reference to this FD.
-func (fd *netFD) readUnlock() {
-	if fd.fdmu.RWUnlock(true) {
-		fd.destroy()
-	}
-}
-
-// Add a reference to this fd and lock for writing.
-// Returns an error if the fd cannot be used.
-func (fd *netFD) writeLock() error {
-	if !fd.fdmu.RWLock(false) {
-		return errClosing
-	}
-	return nil
-}
-
-// Unlock for writing and remove a reference to this FD.
-func (fd *netFD) writeUnlock() {
-	if fd.fdmu.RWUnlock(false) {
-		fd.destroy()
-	}
-}
-
 func (fd *netFD) Read(b []byte) (n int, err error) {
 	if !fd.ok() || fd.data == nil {
 		return 0, syscall.EINVAL
@@ -131,7 +76,13 @@ func (fd *netFD) Read(b []byte) (n int, err error) {
 		return 0, err
 	}
 	defer fd.readUnlock()
+	if len(b) == 0 {
+		return 0, nil
+	}
 	n, err = fd.data.Read(b)
+	if isHangup(err) {
+		err = io.EOF
+	}
 	if fd.net == "udp" && err == io.EOF {
 		n = 0
 		err = nil
@@ -165,7 +116,7 @@ func (fd *netFD) closeWrite() error {
 }
 
 func (fd *netFD) Close() error {
-	if !fd.fdmu.IncrefAndClose() {
+	if !fd.fdmu.increfAndClose() {
 		return errClosing
 	}
 	if !fd.ok() {
@@ -206,9 +157,7 @@ func (l *TCPListener) dup() (*os.File, error) {
 }
 
 func (fd *netFD) file(f *os.File, s string) (*os.File, error) {
-	syscall.ForkLock.RLock()
 	dfd, err := syscall.Dup(int(f.Fd()), -1)
-	syscall.ForkLock.RUnlock()
 	if err != nil {
 		return nil, os.NewSyscallError("dup", err)
 	}
@@ -234,3 +183,7 @@ func setReadBuffer(fd *netFD, bytes int) error {
 func setWriteBuffer(fd *netFD, bytes int) error {
 	return syscall.EPLAN9
 }
+
+func isHangup(err error) bool {
+	return err != nil && stringsHasSuffix(err.Error(), "Hangup")
+}