[GitHub] [activemq-artemis] wy96f commented on a change in pull request #2743: ARTEMIS-2418 Race conditions between cursor movement and page writing

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wy96f commented on a change in pull request #2743: ARTEMIS-2418 Race conditions between cursor movement and page writing
URL: https://github.com/apache/activemq-artemis/pull/2743#discussion_r303727558
 
 

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 File path: tests/extra-tests/src/test/java/org/apache/activemq/artemis/tests/extras/byteman/RaceOnCursorIteratorTest.java
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+/**
+ * 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
+ * <p/>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p/>
+ * 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.activemq.artemis.tests.extras.byteman;
+
+import java.util.HashMap;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import org.apache.activemq.artemis.api.core.ActiveMQBuffer;
+import org.apache.activemq.artemis.api.core.SimpleString;
+import org.apache.activemq.artemis.api.core.client.ClientSession;
+import org.apache.activemq.artemis.api.core.client.ClientSessionFactory;
+import org.apache.activemq.artemis.api.core.client.ServerLocator;
+import org.apache.activemq.artemis.core.config.Configuration;
+import org.apache.activemq.artemis.core.message.impl.CoreMessage;
+import org.apache.activemq.artemis.core.paging.PagingStore;
+import org.apache.activemq.artemis.core.paging.cursor.PagedReference;
+import org.apache.activemq.artemis.core.server.ActiveMQServer;
+import org.apache.activemq.artemis.core.server.Queue;
+import org.apache.activemq.artemis.core.server.impl.RoutingContextImpl;
+import org.apache.activemq.artemis.core.settings.impl.AddressSettings;
+import org.apache.activemq.artemis.tests.util.ActiveMQTestBase;
+import org.apache.activemq.artemis.utils.RandomUtil;
+import org.jboss.byteman.contrib.bmunit.BMRule;
+import org.jboss.byteman.contrib.bmunit.BMRules;
+import org.jboss.byteman.contrib.bmunit.BMUnitRunner;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(BMUnitRunner.class)
+public class RaceOnCursorIteratorTest extends ActiveMQTestBase {
+
+   private static ServerLocator locator;
+
+   private static ActiveMQServer server;
+
+   private static ClientSessionFactory sf;
+
+   private static ClientSession session;
+
+   private static Queue queue;
+
+   private static final ReentrantReadWriteLock.ReadLock lock = new ReentrantReadWriteLock().readLock();
+
+   private static final int PAGE_MAX = 100 * 1024;
+
+   private static final int PAGE_SIZE = 10 * 1024;
+
+   static final SimpleString ADDRESS = new SimpleString("SimpleAddress");
+
+   static boolean skipLivePageCache = false;
+
+   static boolean skipNullPageCache = false;
+
+   static boolean moveNextPageCalled = false;
+
+   @Override
+   @Before
+   public void setUp() throws Exception {
+      super.setUp();
+      skipLivePageCache = false;
+      skipNullPageCache = false;
+      moveNextPageCalled = false;
+      locator = createInVMNonHALocator();
+
+      clearDataRecreateServerDirs();
+
+      Configuration config = createDefaultConfig(false);
+
+      config.setJournalSyncNonTransactional(false);
+
+      HashMap<String, AddressSettings> map = new HashMap<>();
+      AddressSettings value = new AddressSettings();
+      map.put(ADDRESS.toString(), value);
+      server = createServer(true, config, PAGE_SIZE, PAGE_MAX, map);
+
+      server.start();
+
+      locator = createInVMNonHALocator();
+
+      locator.setBlockOnNonDurableSend(true);
+      locator.setBlockOnDurableSend(true);
+      locator.setBlockOnAcknowledge(false);
+      locator.setConsumerWindowSize(0);
+
+      sf = createSessionFactory(locator);
+
+      session = sf.createSession(false, true, true);
+
+      session.createQueue(ADDRESS, ADDRESS, null, true);
+
+      queue = server.locateQueue(ADDRESS);
+      queue.getPageSubscription().getPagingStore().startPaging();
+   }
+
+   @Override
+   @After
+   public void tearDown() throws Exception {
+      session.close();
+      sf.close();
+      locator.close();
+      server.stop();
+      super.tearDown();
+   }
+
+   public static void raceAddLivePageCache() throws Exception {
+      if (skipLivePageCache) {
+         createMessage(1);
+
+         queue.getPageSubscription().getPagingStore().forceAnotherPage();
+
+         createMessage(2);
+      }
+      moveNextPageCalled = true;
+   }
+
+   public static void raceAddTwoCaches() throws Exception {
+      if (skipNullPageCache && moveNextPageCalled) {
+         createMessage(1);
+
+         queue.getPageSubscription().getPagingStore().forceAnotherPage();
+
+         createMessage(2);
+      }
+   }
+
+   @Test
+   @BMRules(
+      rules = {@BMRule(
+         name = "raceLiveCache",
+         targetClass = "org.apache.activemq.artemis.core.paging.cursor.impl.PageSubscriptionImpl",
+         targetMethod = "moveNextPage",
+         targetLocation = "EXIT",
+         action = "org.apache.activemq.artemis.tests.extras.byteman.RaceOnCursorIteratorTest.raceAddLivePageCache()")})
+   public void testSkipLivePageCache() {
+      skipLivePageCache = true;
+      // Simulate scenario #1 depicted in https://issues.apache.org/jira/browse/ARTEMIS-2418
+      PagedReference ref = queue.getPageSubscription().iterator().next();
+      assertTrue("first msg should not be " + (ref == null ? "null" : ref.getPagedMessage().getMessage().getMessageID()),
+                 ref == null || ref.getPagedMessage().getMessage().getMessageID() == 1);
+   }
+
+   @Test
+   @BMRules(
+      rules = {@BMRule(
 
 Review comment:
   Test testSkipLivePageCache simulates scenario 1. 
   > Meanwhile p1 is filled with message m1 and p2 is created with m2.
   This is achieved by calling raceAddLivePageCache after entry of PageSubscriptionImpl::moveNextPage.
   
   Test testSkipNullPageCache simulates scenario 2. 
   > When we call internalGetNext(), the cursor moves to position(p2, 0) and get null page cache since p2 is not yet created. Then p2 is created with m1 and p3 is created with m2 which means current writing page no. is p3
   This is achieved by calling raceAddTwoCaches after the first PageSubscriptionImpl::moveNextPage and after PageSubscriptionImpl::getPageCache.
   
   I have added the code line in the previous comment. Hope this helped to understand the race.
   
   I wrote the byteman test to justify the race conditions. As you said, the test is tricky and fragile, so it's ok for me to remove it :)
   

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