org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/GcConcurrentTest.java

/*
 * Copyright (C) 2012, Christian Halstrick <christian.halstrick@sap.com>
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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package org.eclipse.jgit.internal.storage.file;

import static java.lang.Integer.valueOf;
import static org.junit.Assert.assertEquals;

import java.io.IOException;
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.Callable;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.EmptyProgressMonitor;
import org.eclipse.jgit.revwalk.RevBlob;
import org.junit.Test;

public class GcConcurrentTest extends GcTestCase {
	@Test
	public void concurrentRepack() throws Exception {
		final CyclicBarrier syncPoint = new CyclicBarrier(2);

		class DoRepack extends EmptyProgressMonitor implements
				Callable<Integer> {

			@Override
			public void beginTask(String title, int totalWork) {
				if (title.equals(JGitText.get().writingObjects)) {
					try {
						syncPoint.await();
					} catch (InterruptedException e) {
						Thread.currentThread().interrupt();
					} catch (BrokenBarrierException ignored) {
						//
					}
				}
			}

			/** @return 0 for success, 1 in case of error when writing pack */
			@Override
			public Integer call() throws Exception {
				try {
					gc.setProgressMonitor(this);
					gc.repack();
					return valueOf(0);
				} catch (IOException e) {
					// leave the syncPoint in broken state so any awaiting
					// threads and any threads that call await in the future get
					// the BrokenBarrierException
					Thread.currentThread().interrupt();
					try {
						syncPoint.await();
					} catch (InterruptedException ignored) {
						//
					}
					return valueOf(1);
				}
			}
		}

		RevBlob a = tr.blob("a");
		tr.lightweightTag("t", a);

		ExecutorService pool = Executors.newFixedThreadPool(2);
		try {
			DoRepack repack1 = new DoRepack();
			DoRepack repack2 = new DoRepack();
			Future<Integer> result1 = pool.submit(repack1);
			Future<Integer> result2 = pool.submit(repack2);
			assertEquals(0, result1.get().intValue() + result2.get().intValue());
		} finally {
			pool.shutdown();
			pool.awaitTermination(Long.MAX_VALUE, TimeUnit.SECONDS);
		}
	}
}