net: add Pipe

R=r
CC=golang-dev
https://golang.org/cl/1004043
diff --git a/src/pkg/net/pipe_test.go b/src/pkg/net/pipe_test.go
new file mode 100644
index 0000000..7e4c6db
--- /dev/null
+++ b/src/pkg/net/pipe_test.go
@@ -0,0 +1,57 @@
+// Copyright 2010 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.
+
+package net
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"testing"
+)
+
+func checkWrite(t *testing.T, w io.Writer, data []byte, c chan int) {
+	n, err := w.Write(data)
+	if err != nil {
+		t.Errorf("write: %v", err)
+	}
+	if n != len(data) {
+		t.Errorf("short write: %d != %d", n, len(data))
+	}
+	c <- 0
+}
+
+func checkRead(t *testing.T, r io.Reader, data []byte, wantErr os.Error) {
+	buf := make([]byte, len(data)+10)
+	n, err := r.Read(buf)
+	if err != wantErr {
+		t.Errorf("read: %v", err)
+		return
+	}
+	if n != len(data) || !bytes.Equal(buf[0:n], data) {
+		t.Errorf("bad read: got %q", buf[0:n])
+		return
+	}
+}
+
+// Test a simple read/write/close sequence.
+// Assumes that the underlying io.Pipe implementation
+// is solid and we're just testing the net wrapping.
+
+func TestPipe(t *testing.T) {
+	c := make(chan int)
+	cli, srv := Pipe()
+	go checkWrite(t, cli, []byte("hello, world"), c)
+	checkRead(t, srv, []byte("hello, world"), nil)
+	<-c
+	go checkWrite(t, srv, []byte("line 2"), c)
+	checkRead(t, cli, []byte("line 2"), nil)
+	<-c
+	go checkWrite(t, cli, []byte("a third line"), c)
+	checkRead(t, srv, []byte("a third line"), nil)
+	<-c
+	go srv.Close()
+	checkRead(t, cli, nil, os.EOF)
+	cli.Close()
+}