--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/jdk.jshell/share/classes/jdk/jshell/execution/MultiplexingOutputStream.java	Wed Jul 20 23:19:09 2016 -0700
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package jdk.jshell.execution;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.UnsupportedEncodingException;
+
+/**
+ * Packetize an OutputStream, dividing it into named channels.
+ *
+ * @author Jan Lahoda
+ */
+class MultiplexingOutputStream extends OutputStream {
+
+    private static final int PACKET_SIZE = 127;
+    private final byte[] name;
+    private final OutputStream delegate;
+
+    MultiplexingOutputStream(String name, OutputStream delegate) {
+        try {
+            this.name = name.getBytes("UTF-8");
+            this.delegate = delegate;
+        } catch (UnsupportedEncodingException ex) {
+            throw new IllegalStateException(ex); //should not happen
+        }
+    }
+
+    @Override
+    public void write(int b) throws IOException {
+        synchronized (delegate) {
+            delegate.write(name.length); //assuming the len is small enough to fit into byte
+            delegate.write(name);
+            delegate.write(1);
+            delegate.write(b);
+            delegate.flush();
+        }
+    }
+
+    @Override
+    public void write(byte[] b, int off, int len) throws IOException {
+        synchronized (delegate) {
+            int i = 0;
+            while (len > 0) {
+                int size = Math.min(PACKET_SIZE, len);
+                delegate.write(name.length); //assuming the len is small enough to fit into byte
+                delegate.write(name);
+                delegate.write(size);
+                delegate.write(b, off + i, size);
+                i += size;
+                len -= size;
+            }
+            delegate.flush();
+        }
+    }
+
+    @Override
+    public void flush() throws IOException {
+        super.flush();
+        delegate.flush();
+    }
+
+    @Override
+    public void close() throws IOException {
+        super.close();
+        delegate.close();
+    }
+
+}