opendaylight/config/config-manager/src/main/java/org/opendaylight/controller/config/manager/impl/osgi/BlankTransactionServiceTracker.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.config.manager.impl.osgi;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import javax.management.ObjectName;
  12 import org.opendaylight.controller.config.api.ConflictingVersionException;
  13 import org.opendaylight.controller.config.api.ValidationException;
  14 import org.opendaylight.controller.config.api.jmx.CommitStatus;
  15 import org.opendaylight.controller.config.manager.impl.ConfigRegistryImpl;
  16 import org.opendaylight.controller.config.spi.ModuleFactory;
  17 import org.osgi.framework.ServiceReference;
  18 import org.osgi.util.tracker.ServiceTrackerCustomizer;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21
  22 /**
  23  * Every time factory is added or removed, blank transaction is triggered to handle
  24  * {@link org.opendaylight.controller.config.spi.ModuleFactory#getDefaultModules(org.opendaylight.controller.config.api.DependencyResolverFactory, org.osgi.framework.BundleContext)}
  25  * functionality.
  26  */
  27 public class BlankTransactionServiceTracker implements ServiceTrackerCustomizer<ModuleFactory, Object> {
  28     private static final Logger LOGGER = LoggerFactory.getLogger(BlankTransactionServiceTracker.class);
  29
  30     public static final int DEFAULT_MAX_ATTEMPTS = 10;
  31
  32     private final BlankTransaction blankTransaction;
  33     private int maxAttempts;
  34
  35     public BlankTransactionServiceTracker(final ConfigRegistryImpl configRegistry) {
  36         this(new BlankTransaction() {
  37             @Override
  38             public CommitStatus hit() throws ValidationException, ConflictingVersionException {
  39                 ObjectName tx = configRegistry.beginConfig(true);
  40                 return configRegistry.commitConfig(tx);
  41             }
  42         });
  43     }
  44
  45     public BlankTransactionServiceTracker(final BlankTransaction blankTransaction) {
  46         this(blankTransaction, DEFAULT_MAX_ATTEMPTS);
  47     }
  48
  49     @VisibleForTesting
  50     BlankTransactionServiceTracker(final BlankTransaction blankTx, final int maxAttempts) {
  51         this.blankTransaction = blankTx;
  52         this.maxAttempts = maxAttempts;
  53     }
  54
  55     @Override
  56     public Object addingService(ServiceReference<ModuleFactory> moduleFactoryServiceReference) {
  57         blankTransaction();
  58         return null;
  59     }
  60
  61     synchronized void blankTransaction() {
  62         // race condition check: config-persister might push new configuration while server is starting up.
  63         ConflictingVersionException lastException = null;
  64         for (int i = 0; i < maxAttempts; i++) {
  65             try {
  66                 // create transaction
  67                 CommitStatus commitStatus = blankTransaction.hit();
  68                 LOGGER.debug("Committed blank transaction with status {}", commitStatus);
  69                 return;
  70             } catch (ConflictingVersionException e) {
  71                 lastException = e;
  72                 try {
  73                     Thread.sleep(1000);
  74                 } catch (InterruptedException interruptedException) {
  75                     Thread.currentThread().interrupt();
  76                     throw new IllegalStateException(interruptedException);
  77                 }
  78             } catch (ValidationException e) {
  79                 LOGGER.error("Validation exception while running blank transaction indicates programming error", e);
  80                 throw new RuntimeException("Validation exception while running blank transaction indicates programming error", e);
  81             }
  82         }
  83         throw new RuntimeException("Maximal number of attempts reached and still cannot get optimistic lock from " +
  84                 "config manager",lastException);
  85     }
  86
  87     @Override
  88     public void modifiedService(ServiceReference <ModuleFactory> moduleFactoryServiceReference, Object o) {
  89         blankTransaction();
  90     }
  91
  92     @Override
  93     public void removedService(ServiceReference<ModuleFactory> moduleFactoryServiceReference, Object o) {
  94         blankTransaction();
  95     }
  96
  97     @VisibleForTesting
  98     static interface BlankTransaction {
  99         CommitStatus hit() throws ValidationException, ConflictingVersionException;
 100     }
 101 }