--- /dev/null 2016-07-18 08:15:00.740233585 -0700 +++ new/src/jdk.jshell/share/classes/jdk/jshell/execution/PipeInputStream.java 2016-07-19 16:57:33.182257303 -0700 @@ -0,0 +1,88 @@ +/* + * 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.InputStream; + +/** + * + * @author Jan Lahoda + */ +class PipeInputStream extends InputStream { + + private static final int INITIAL_SIZE = 128; + private int[] buffer = new int[INITIAL_SIZE]; + private int start; + private int end; + private boolean closed; + + @Override + public synchronized int read() { + while (start == end) { + if (closed) { + return -1; + } + try { + wait(); + } catch (InterruptedException ex) { + //ignore + } + } + try { + return buffer[start]; + } finally { + start = (start + 1) % buffer.length; + } + } + + public synchronized void write(int b) { + if (closed) { + throw new IllegalStateException("Already closed."); + } + int newEnd = (end + 1) % buffer.length; + if (newEnd == start) { + //overflow: + int[] newBuffer = new int[buffer.length * 2]; + int rightPart = (end > start ? end : buffer.length) - start; + int leftPart = end > start ? 0 : start - 1; + System.arraycopy(buffer, start, newBuffer, 0, rightPart); + System.arraycopy(buffer, 0, newBuffer, rightPart, leftPart); + buffer = newBuffer; + start = 0; + end = rightPart + leftPart; + newEnd = end + 1; + } + buffer[end] = b; + end = newEnd; + notifyAll(); + } + + @Override + public synchronized void close() { + closed = true; + notifyAll(); + } + +}