ARTEMIS-5873 mitigate infinite loop on shutdown

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/FileLockNodeManager.java

@@ -20,6 +20,8 @@
 import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.nio.ByteBuffer;
+import java.nio.channels.Channel;
+import java.nio.channels.ClosedChannelException;
 import java.nio.channels.FileChannel;
 import java.nio.channels.FileLock;
 import java.util.Date;
@@ -233,7 +235,7 @@ public void startBackup() throws NodeManagerException {
       ActiveMQServerLogger.LOGGER.waitingToBecomeBackup();
       try {
          backupLock = lock(FileLockNodeManager.BACKUP_LOCK_POS);
-      } catch (ActiveMQLockAcquisitionTimeoutException e) {
+      } catch (ClosedChannelException | ActiveMQLockAcquisitionTimeoutException e) {
          throw new NodeManagerException(e);
       }
       ActiveMQServerLogger.LOGGER.gotBackupLock();
@@ -267,7 +269,7 @@ public void activationComplete() {
                }
             }
          };
-      } catch (ActiveMQLockAcquisitionTimeoutException e) {
+      } catch (ClosedChannelException | ActiveMQLockAcquisitionTimeoutException e) {
          throw new NodeManagerException(e);
       }
    }
@@ -328,7 +330,7 @@ private void writeFileLockStatus(byte status) throws NodeManagerException {
       bb.put(status);
       bb.position(0);
       try {
-         if (!channel.isOpen()) {
+         if (channel == null || !channel.isOpen()) {
             setUpServerLockFile();
          }
          FileLock lock = null;
@@ -412,7 +414,7 @@ protected FileLock tryLock(final int lockPos) throws IOException {
       }
    }
 
-   protected FileLock lock(final int lockPosition) throws ActiveMQLockAcquisitionTimeoutException {
+   protected FileLock lock(final int lockPosition) throws ClosedChannelException, ActiveMQLockAcquisitionTimeoutException {
       long start = System.nanoTime();
       boolean isRecurringFailure = false;
 
@@ -437,6 +439,9 @@ protected FileLock lock(final int lockPosition) throws ActiveMQLockAcquisitionTi
             } else {
                return lock;
             }
+         } catch (ClosedChannelException e) {
+            // This is an unrecoverable error as there's no guarantee the channel will ever be opened again.
+            throw e;
          } catch (IOException e) {
             // IOException during trylock() may be a temporary issue, e.g. NFS volume not being accessible
 
@@ -575,4 +580,8 @@ private boolean hasBeenModified(byte state) {
          return modified;
       }
    }
+
+   protected Channel getChannel() {
+      return channel;
+   }
 }

artemis-server/src/test/java/org/apache/activemq/artemis/core/server/impl/FileLockNodeManagerTest.java

@@ -0,0 +1,47 @@
+/*
+ * 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.activemq.artemis.core.server.impl;
+
+import java.io.File;
+import java.nio.channels.ClosedChannelException;
+
+import org.apache.activemq.artemis.tests.extensions.TargetTempDirFactory;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
+import org.junit.jupiter.api.io.TempDir;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class FileLockNodeManagerTest {
+
+   @TempDir(factory = TargetTempDirFactory.class)
+   public File temporaryFolder;
+
+   @Test
+   @Timeout(3)
+   public void testChannelClosed() throws Exception {
+      FileLockNodeManager manager = new FileLockNodeManager(temporaryFolder, false);
+
+      // calling this method sets up the internal FileChannel as it would be in normal usage
+      manager.pausePrimaryServer();
+
+      // now close the channel so we can ensure it throws
+      manager.getChannel().close();
+
+      assertThrows(ClosedChannelException.class, () -> manager.lock(0));
+   }
+}