88 lines
3.1 KiB
Java
88 lines
3.1 KiB
Java
/*
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* Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/*
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* @test
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* @bug 6823609
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* @summary Selector.select can hangs on Windows for cases where a helper thread
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* becomes redudant but a new helper is immediately needed.
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*/
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import java.nio.channels.*;
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import java.io.IOException;
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public class HelperSlowToDie {
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private static final int CHANNELS_PER_THREAD = 1023;
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private static final int TEST_ITERATIONS = 200;
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private static volatile boolean done;
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public static void main(String[] args) throws IOException {
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if (!System.getProperty("os.name").startsWith("Windows")) {
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System.out.println("Test skipped as it verifies a Windows specific bug");
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return;
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}
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Selector sel = Selector.open();
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// register channels
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SocketChannel[] channels = new SocketChannel[CHANNELS_PER_THREAD];
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for (int i=0; i<CHANNELS_PER_THREAD; i++) {
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SocketChannel sc = SocketChannel.open();
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sc.configureBlocking(false);
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sc.register(sel, SelectionKey.OP_CONNECT);
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channels[i] = sc;
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}
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sel.selectNow();
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// Start threads to swamp all cores but one. This improves the chances
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// of duplicating the bug.
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Runnable busy = new Runnable() {
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public void run() {
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while (!done) ; // no nothing
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}
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};
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int ncores = Runtime.getRuntime().availableProcessors();
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for (int i=0; i<ncores-1; i++)
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new Thread(busy).start();
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// Loop changing the number of channels from 1023 to 1024 and back.
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for (int i=0; i<TEST_ITERATIONS; i++) {
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SocketChannel sc = SocketChannel.open();
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sc.configureBlocking(false);
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sc.register(sel, SelectionKey.OP_CONNECT);
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sel.selectNow(); // cause helper to spin up
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sc.close();
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sel.selectNow(); // cause helper to retire
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}
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// terminate busy threads
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done = true;
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// clean-up
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for (int i=0; i<CHANNELS_PER_THREAD; i++) {
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channels[i].close();
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}
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sel.close();
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}
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}
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