Fix checkstyle issues to enforce it

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

diff --git a/opendaylight/config/config-manager/src/main/java/org/opendaylight/controller/config/manager/impl/osgi/BlankTransactionServiceTracker.java b/opendaylight/config/config-manager/src/main/java/org/opendaylight/controller/config/manager/impl/osgi/BlankTransactionServiceTracker.java
index de1a425ce64813f5c783c710367cee51232e66fc..2649b145d0509badbcd88897ca99a83282bed6b5 100644 (file)
--- a/opendaylight/config/config-manager/src/main/java/org/opendaylight/controller/config/manager/impl/osgi/BlankTransactionServiceTracker.java
+++ b/opendaylight/config/config-manager/src/main/java/org/opendaylight/controller/config/manager/impl/osgi/BlankTransactionServiceTracker.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
+ * Copyright (c) 2013, 2017 Cisco Systems, Inc. and others.  All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
@@ -7,6 +7,13 @@
  */
 package org.opendaylight.controller.config.manager.impl.osgi;
 
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import javax.management.ObjectName;
+import org.opendaylight.controller.config.api.ConflictingVersionException;
+import org.opendaylight.controller.config.api.ValidationException;
 import org.opendaylight.controller.config.api.jmx.CommitStatus;
 import org.opendaylight.controller.config.manager.impl.ConfigRegistryImpl;
 import org.opendaylight.controller.config.spi.ModuleFactory;
@@ -15,42 +22,91 @@ import org.osgi.util.tracker.ServiceTrackerCustomizer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import javax.management.ObjectName;
-
 /**
- * Every time factory is added or removed, blank transaction is triggered to handle
- * {@link org.opendaylight.controller.config.spi.ModuleFactory#getDefaultModules(org.opendaylight.controller.config.api.DependencyResolverFactory)}
- * functionality.
+ * Every time factory is added or removed, blank transaction is triggered to
+ * handle.
  */
 public class BlankTransactionServiceTracker implements ServiceTrackerCustomizer<ModuleFactory, Object> {
-    private static final Logger logger = LoggerFactory.getLogger(BlankTransactionServiceTracker.class);
+    private static final Logger LOG = LoggerFactory.getLogger(BlankTransactionServiceTracker.class);
+
+    public static final int DEFAULT_MAX_ATTEMPTS = 10;
 
-    private final ConfigRegistryImpl configRegistry;
+    private final BlankTransaction blankTransaction;
+    private final ExecutorService txExecutor;
+    private final int maxAttempts;
 
-    public BlankTransactionServiceTracker(ConfigRegistryImpl configRegistry) {
-        this.configRegistry = configRegistry;
+    public BlankTransactionServiceTracker(final ConfigRegistryImpl configRegistry) {
+        this(() -> {
+            ObjectName tx = configRegistry.beginConfig(true);
+            return configRegistry.commitConfig(tx);
+        });
+    }
+
+    public BlankTransactionServiceTracker(final BlankTransaction blankTransaction) {
+        this(blankTransaction, DEFAULT_MAX_ATTEMPTS, Executors
+                .newSingleThreadExecutor(new ThreadFactoryBuilder().setNameFormat("config-blank-txn-%d").build()));
+    }
+
+    @VisibleForTesting
+    BlankTransactionServiceTracker(final BlankTransaction blankTx, final int maxAttempts,
+            final ExecutorService txExecutor) {
+        this.blankTransaction = blankTx;
+        this.maxAttempts = maxAttempts;
+        this.txExecutor = txExecutor;
     }
 
     @Override
-    public Object addingService(ServiceReference<ModuleFactory> moduleFactoryServiceReference) {
-        blankTransaction();
+    public Object addingService(final ServiceReference<ModuleFactory> moduleFactoryServiceReference) {
+        blankTransactionAsync();
         return null;
     }
 
-    private synchronized void blankTransaction() {
-        // create transaction
-        ObjectName tx = configRegistry.beginConfig();
-        CommitStatus commitStatus = configRegistry.commitConfig(tx);
-        logger.debug("Committed blank transaction with status {}", commitStatus);
+    private void blankTransactionAsync() {
+        txExecutor.execute(this::blankTransactionSync);
+    }
+
+    void blankTransactionSync() {
+        // race condition check: config-persister might push new configuration while
+        // server is starting up.
+        ConflictingVersionException lastException = null;
+        for (int i = 0; i < maxAttempts; i++) {
+            try {
+                // create transaction
+                CommitStatus commitStatus = blankTransaction.hit();
+                LOG.debug("Committed blank transaction with status {}", commitStatus);
+                return;
+            } catch (final ConflictingVersionException e) {
+                lastException = e;
+                try {
+                    Thread.sleep(1000);
+                } catch (final InterruptedException interruptedException) {
+                    Thread.currentThread().interrupt();
+                    LOG.debug("blankTransactionSync was interrupted");
+                    return;
+                }
+            } catch (final ValidationException e) {
+                LOG.error("Validation exception while running blank transaction indicates programming error", e);
+            }
+        }
+
+        LOG.error("Maximal number of attempts reached and still cannot get optimistic lock from config manager",
+                lastException);
     }
 
     @Override
-    public void modifiedService(ServiceReference<ModuleFactory> moduleFactoryServiceReference, Object o) {
-        blankTransaction();
+    public void modifiedService(final ServiceReference<ModuleFactory> moduleFactoryServiceReference,
+            final Object object) {
+        blankTransactionAsync();
     }
 
     @Override
-    public void removedService(ServiceReference<ModuleFactory> moduleFactoryServiceReference, Object o) {
-        blankTransaction();
+    public void removedService(final ServiceReference<ModuleFactory> moduleFactoryServiceReference,
+            final Object object) {
+        blankTransactionAsync();
+    }
+
+    @VisibleForTesting
+    interface BlankTransaction {
+        CommitStatus hit() throws ValidationException, ConflictingVersionException;
     }
 }