| /** |
| * 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.hadoop.hbase.regionserver; |
| |
| import java.util.Random; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| import java.util.concurrent.atomic.AtomicLong; |
| import org.apache.hadoop.hbase.HBaseClassTestRule; |
| import org.apache.hadoop.hbase.testclassification.MediumTests; |
| import org.apache.hadoop.hbase.testclassification.RegionServerTests; |
| import org.junit.Assert; |
| import org.junit.ClassRule; |
| import org.junit.Test; |
| import org.junit.experimental.categories.Category; |
| |
| /** |
| * This is a hammer test that verifies MultiVersionConcurrencyControl in a |
| * multiple writer single reader scenario. |
| */ |
| @Category({RegionServerTests.class, MediumTests.class}) |
| public class TestMultiVersionConcurrencyControl { |
| |
| @ClassRule |
| public static final HBaseClassTestRule CLASS_RULE = |
| HBaseClassTestRule.forClass(TestMultiVersionConcurrencyControl.class); |
| |
| static class Writer implements Runnable { |
| final AtomicBoolean finished; |
| final MultiVersionConcurrencyControl mvcc; |
| final AtomicBoolean status; |
| |
| Writer(AtomicBoolean finished, MultiVersionConcurrencyControl mvcc, AtomicBoolean status) { |
| this.finished = finished; |
| this.mvcc = mvcc; |
| this.status = status; |
| } |
| |
| private Random rnd = new Random(); |
| public boolean failed = false; |
| |
| @Override |
| public void run() { |
| while (!finished.get()) { |
| MultiVersionConcurrencyControl.WriteEntry e = |
| mvcc.begin(); |
| // System.out.println("Begin write: " + e.getWriteNumber()); |
| // 10 usec - 500usec (including 0) |
| int sleepTime = rnd.nextInt(500); |
| // 500 * 1000 = 500,000ns = 500 usec |
| // 1 * 100 = 100ns = 1usec |
| try { |
| if (sleepTime > 0) Thread.sleep(0, sleepTime * 1000); |
| } catch (InterruptedException e1) { |
| } |
| try { |
| mvcc.completeAndWait(e); |
| } catch (RuntimeException ex) { |
| // got failure |
| System.out.println(ex.toString()); |
| ex.printStackTrace(); |
| status.set(false); |
| return; |
| // Report failure if possible. |
| } |
| } |
| } |
| } |
| |
| @Test |
| public void testParallelism() throws Exception { |
| final MultiVersionConcurrencyControl mvcc = new MultiVersionConcurrencyControl(); |
| |
| final AtomicBoolean finished = new AtomicBoolean(false); |
| |
| // fail flag for the reader thread |
| final AtomicBoolean readerFailed = new AtomicBoolean(false); |
| final AtomicLong failedAt = new AtomicLong(); |
| Runnable reader = new Runnable() { |
| @Override |
| public void run() { |
| long prev = mvcc.getReadPoint(); |
| while (!finished.get()) { |
| long newPrev = mvcc.getReadPoint(); |
| if (newPrev < prev) { |
| // serious problem. |
| System.out.println("Reader got out of order, prev: " + prev + " next was: " + newPrev); |
| readerFailed.set(true); |
| // might as well give up |
| failedAt.set(newPrev); |
| return; |
| } |
| } |
| } |
| }; |
| |
| // writer thread parallelism. |
| int n = 20; |
| Thread[] writers = new Thread[n]; |
| AtomicBoolean[] statuses = new AtomicBoolean[n]; |
| Thread readThread = new Thread(reader); |
| |
| for (int i = 0; i < n; ++i) { |
| statuses[i] = new AtomicBoolean(true); |
| writers[i] = new Thread(new Writer(finished, mvcc, statuses[i])); |
| writers[i].start(); |
| } |
| readThread.start(); |
| |
| try { |
| Thread.sleep(10 * 1000); |
| } catch (InterruptedException ex) { |
| } |
| |
| finished.set(true); |
| |
| readThread.join(); |
| for (int i = 0; i < n; ++i) { |
| writers[i].join(); |
| } |
| |
| // check failure. |
| Assert.assertFalse(readerFailed.get()); |
| for (int i = 0; i < n; ++i) { |
| Assert.assertTrue(statuses[i].get()); |
| } |
| } |
| } |