Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.jackrabbit.core.data; import java.io.ByteArrayInputStream; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.HashSet; import java.util.Random; import java.util.Set; import junit.framework.TestCase; import org.apache.commons.io.FileUtils; import org.apache.jackrabbit.core.data.db.DbDataStore; import org.apache.jackrabbit.core.util.db.ConnectionFactory; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Tests concurrent garbage collection, see JCR-2026 */ public class ConcurrentGcTest extends TestCase { static final Logger LOG = LoggerFactory.getLogger(ConcurrentGcTest.class); private static final String TEST_DIR = "target/ConcurrentGcTest"; protected DataStore store; private Thread gcLoopThread; protected Set<DataIdentifier> ids = Collections.synchronizedSet(new HashSet<DataIdentifier>()); protected volatile boolean gcLoopStop; protected volatile Exception gcException; public void setUp() throws IOException { deleteAll(); } public void tearDown() throws IOException { deleteAll(); } private void deleteAll() throws IOException { FileUtils.deleteDirectory(new File(TEST_DIR)); } public void testDatabases() throws Exception { // doTestDatabase( // "org.h2.Driver", // "jdbc:h2:" + TEST_DIR + "/db", // "sa", "sa"); // not enabled by default // doTestDatabase( // "org.postgresql.Driver", // "jdbc:postgresql:test", // "sa", "sa"); // not enabled by default // doTestDatabase( // "com.mysql.jdbc.Driver", // "jdbc:postgresql:test", // "sa", "sa"); // fails with a deadlock // doTestDatabase( // "org.apache.derby.jdbc.EmbeddedDriver", // "jdbc:derby:" + TEST_DIR + "/db;create=true", // "sa", "sa"); } private void doTestDatabase(String driver, String url, String user, String password) throws Exception { ConnectionFactory pool = new ConnectionFactory(); try { DbDataStore store = new DbDataStore(); store.setConnectionFactory(pool); ids.clear(); store.setDriver(driver); store.setUrl(url); store.setUser(user); store.setPassword(password); store.init("target/test-db-datastore"); store.setMinRecordLength(0); doTest(store); } finally { pool.close(); } } public void testFile() throws Exception { FileDataStore store = new FileDataStore(); store.setPath(TEST_DIR + "/fs"); store.init(TEST_DIR + "/fs"); store.setMinRecordLength(0); doTest(store); } void doTest(DataStore store) throws Exception { this.store = store; Random r = new Random(); concurrentGcLoopStart(); int len = 100; if (getTestScale() > 1) { len = 1000; } for (int i = 0; i < len && gcException == null; i++) { LOG.info("test " + i); byte[] data = new byte[3]; r.nextBytes(data); DataRecord rec = store.addRecord(new ByteArrayInputStream(data)); LOG.debug(" added " + rec.getIdentifier()); if (r.nextBoolean()) { LOG.debug(" added " + rec.getIdentifier() + " -> keep reference"); ids.add(rec.getIdentifier()); store.getRecord(rec.getIdentifier()); } if (r.nextInt(100) == 0) { LOG.debug("clear i: " + i); ids.clear(); } } concurrentGcLoopStop(); store.close(); } private void concurrentGcLoopStart() { gcLoopStop = false; gcException = null; gcLoopThread = new Thread() { public void run() { try { while (!gcLoopStop) { if (ids.size() > 0) { // store.clearInUse(); long now = System.currentTimeMillis(); LOG.debug("gc now: " + now); store.updateModifiedDateOnAccess(now); for (DataIdentifier id : new ArrayList<DataIdentifier>(ids)) { LOG.debug(" gc touch " + id); store.getRecord(id); } int count = store.deleteAllOlderThan(now); LOG.debug("gc now: " + now + " done, deleted: " + count); } } } catch (DataStoreException e) { gcException = e; } } }; gcLoopThread.start(); } private void concurrentGcLoopStop() throws Exception { gcLoopStop = true; gcLoopThread.join(); if (gcException != null) { throw gcException; } } static int getTestScale() { return Integer.parseInt(System.getProperty("jackrabbit.test.scale", "1")); } }