ONOS-4118 Added synchronization and resiliency to Bmv2ThriftClient

Due to the multi-threaded nature of drivers, calls to a Bmv2ThriftClient
could result in a race condition if not properly synchronized. Also,
once open, transport session might close due to several reasons. Now the
client calls are synchronized and automatically wrapped in a try/catch
that tries to re-open the session for fixed number of times before
giving up.

Change-Id: I5dcdd5a6304406dc6d9d3a0ccf7f16cdbf3b9573

@@ -20,6 +20,7 @@ import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.commons.lang3.tuple.Triple;
+import org.onosproject.bmv2.api.runtime.Bmv2Client;
 import org.onosproject.bmv2.api.runtime.Bmv2MatchKey;
 import org.onosproject.bmv2.api.runtime.Bmv2RuntimeException;
 import org.onosproject.bmv2.api.runtime.Bmv2TableEntry;
@@ -84,7 +85,7 @@ public class Bmv2FlowRuleDriver extends AbstractHandlerBehaviour
 
         DeviceId deviceId = handler().data().deviceId();
 
-        Bmv2ThriftClient deviceClient;
+        Bmv2Client deviceClient;
         try {
             deviceClient = Bmv2ThriftClient.of(deviceId);
         } catch (Bmv2RuntimeException e) {

@@ -18,6 +18,7 @@ package org.onosproject.drivers.bmv2;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
+import org.onosproject.bmv2.api.runtime.Bmv2Client;
 import org.onosproject.bmv2.api.runtime.Bmv2RuntimeException;
 import org.onosproject.bmv2.ctl.Bmv2ThriftClient;
 import org.onosproject.net.DefaultAnnotations;
@@ -41,7 +42,7 @@ public class Bmv2PortGetterDriver extends AbstractHandlerBehaviour
 
     @Override
     public List<PortDescription> getPorts() {
-        Bmv2ThriftClient deviceClient;
+        Bmv2Client deviceClient;
         try {
             deviceClient = Bmv2ThriftClient.of(handler().data().deviceId());
         } catch (Bmv2RuntimeException e) {

+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.bmv2.api.runtime;
+
+import java.util.Collection;
+
+/**
+ * RPC client to control a BMv2 device.
+ */
+public interface Bmv2Client {
+    /**
+     * Adds a new table entry.
+     *
+     * @param entry a table entry value
+     * @return table-specific entry ID
+     * @throws Bmv2RuntimeException if any error occurs
+     */
+    long addTableEntry(Bmv2TableEntry entry) throws Bmv2RuntimeException;
+
+    /**
+     * Modifies a currently installed entry by updating its action.
+     *
+     * @param tableName string value of table name
+     * @param entryId   long value of entry ID
+     * @param action    an action value
+     * @throws Bmv2RuntimeException if any error occurs
+     */
+    void modifyTableEntry(String tableName,
+                          long entryId, Bmv2Action action)
+            throws Bmv2RuntimeException;
+
+    /**
+     * Deletes currently installed entry.
+     *
+     * @param tableName string value of table name
+     * @param entryId   long value of entry ID
+     * @throws Bmv2RuntimeException if any error occurs
+     */
+    void deleteTableEntry(String tableName,
+                          long entryId) throws Bmv2RuntimeException;
+
+    /**
+     * Sets table default action.
+     *
+     * @param tableName string value of table name
+     * @param action    an action value
+     * @throws Bmv2RuntimeException if any error occurs
+     */
+    void setTableDefaultAction(String tableName, Bmv2Action action)
+            throws Bmv2RuntimeException;
+
+    /**
+     * Returns information of the ports currently configured in the switch.
+     *
+     * @return collection of port information
+     * @throws Bmv2RuntimeException if any error occurs
+     */
+    Collection<Bmv2PortInfo> getPortsInfo() throws Bmv2RuntimeException;
+
+    /**
+     * Return a string representation of a table content.
+     *
+     * @param tableName string value of table name
+     * @return table string dump
+     * @throws Bmv2RuntimeException if any error occurs
+     */
+    String dumpTable(String tableName) throws Bmv2RuntimeException;
+
+    /**
+     * Reset the state of the switch (e.g. delete all entries, etc.).
+     *
+     * @throws Bmv2RuntimeException if any error occurs
+     */
+    void resetState() throws Bmv2RuntimeException;
+}

+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed 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.
+ */
+
+/*
+ * Most of the code of this class was copied from:
+ * http://liveramp.com/engineering/reconnecting-thrift-client/
+ */
+
+package org.onosproject.bmv2.ctl;
+
+import com.google.common.collect.ImmutableSet;
+import org.apache.thrift.TServiceClient;
+import org.apache.thrift.transport.TTransport;
+import org.apache.thrift.transport.TTransportException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.util.Set;
+
+/**
+ * Thrift client wrapper that attempts a few reconnects before giving up a method call execution. It al provides
+ * synchronization between calls (automatically serialize multiple calls to the same client from different threads).
+ */
+public final class SafeThriftClient {
+
+    private static final Logger LOG = LoggerFactory.getLogger(SafeThriftClient.class);
+
+    /**
+     * List of causes which suggest a restart might fix things (defined as constants in {@link TTransportException}).
+     */
+    private static final Set<Integer> RESTARTABLE_CAUSES = ImmutableSet.of(TTransportException.NOT_OPEN,
+                                                                           TTransportException.END_OF_FILE,
+                                                                           TTransportException.TIMED_OUT,
+                                                                           TTransportException.UNKNOWN);
+
+    private SafeThriftClient() {
+        // ban constructor.
+    }
+
+    /**
+     * Reflectively wraps an already existing Thrift client.
+     *
+     * @param baseClient      the client to wrap
+     * @param clientInterface the interface that the client implements
+     * @param options         options that control behavior of the reconnecting client
+     * @param <T>
+     * @param <C>
+     * @return
+     */
+    public static <T extends TServiceClient, C> C wrap(T baseClient, Class<C> clientInterface, Options options) {
+        Object proxyObject = Proxy.newProxyInstance(clientInterface.getClassLoader(),
+                                                    new Class<?>[]{clientInterface},
+                                                    new ReconnectingClientProxy<T>(baseClient,
+                                                                                   options.getNumRetries(),
+                                                                                   options.getTimeBetweenRetries()));
+
+        return (C) proxyObject;
+    }
+
+    /**
+     * Reflectively wraps an already existing Thrift client.
+     *
+     * @param baseClient the client to wrap
+     * @param options    options that control behavior of the reconnecting client
+     * @param <T>
+     * @param <C>
+     * @return
+     */
+    public static <T extends TServiceClient, C> C wrap(T baseClient, Options options) {
+        Class<?>[] interfaces = baseClient.getClass().getInterfaces();
+
+        for (Class<?> iface : interfaces) {
+            if (iface.getSimpleName().equals("Iface")
+                    && iface.getEnclosingClass().equals(baseClient.getClass().getEnclosingClass())) {
+                return (C) wrap(baseClient, iface, options);
+            }
+        }
+
+        throw new RuntimeException("Class needs to implement Iface directly. Use wrap(TServiceClient, Class) instead.");
+    }
+
+    /**
+     * Reflectively wraps an already existing Thrift client.
+     *
+     * @param baseClient      the client to wrap
+     * @param clientInterface the interface that the client implements
+     * @param <T>
+     * @param <C>
+     * @return
+     */
+    public static <T extends TServiceClient, C> C wrap(T baseClient, Class<C> clientInterface) {
+        return wrap(baseClient, clientInterface, Options.defaults());
+    }
+
+    /**
+     * Reflectively wraps an already existing Thrift client.
+     *
+     * @param baseClient the client to wrap
+     * @param <T>
+     * @param <C>
+     * @return
+     */
+    public static <T extends TServiceClient, C> C wrap(T baseClient) {
+        return wrap(baseClient, Options.defaults());
+    }
+
+    /**
+     * Reconnection options for {@link SafeThriftClient}.
+     */
+    public static class Options {
+        private int numRetries;
+        private long timeBetweenRetries;
+
+        /**
+         * Creates new options with the given parameters.
+         *
+         * @param numRetries         the maximum number of times to try reconnecting before giving up and throwing an
+         *                           exception
+         * @param timeBetweenRetries the number of milliseconds to wait in between reconnection attempts.
+         */
+        public Options(int numRetries, long timeBetweenRetries) {
+            this.numRetries = numRetries;
+            this.timeBetweenRetries = timeBetweenRetries;
+        }
+
+        private static Options defaults() {
+            return new Options(5, 10000L);
+        }
+
+        private int getNumRetries() {
+            return numRetries;
+        }
+
+        private long getTimeBetweenRetries() {
+            return timeBetweenRetries;
+        }
+    }
+
+    /**
+     * Helper proxy class. Attempts to call method on proxy object wrapped in try/catch. If it fails, it attempts a
+     * reconnect and tries the method again.
+     *
+     * @param <T>
+     */
+    private static class ReconnectingClientProxy<T extends TServiceClient> implements InvocationHandler {
+        private final T baseClient;
+        private final int maxRetries;
+        private final long timeBetweenRetries;
+
+        public ReconnectingClientProxy(T baseClient, int maxRetries, long timeBetweenRetries) {
+            this.baseClient = baseClient;
+            this.maxRetries = maxRetries;
+            this.timeBetweenRetries = timeBetweenRetries;
+        }
+
+        private static void reconnectOrThrowException(TTransport transport, int maxRetries, long timeBetweenRetries)
+                throws TTransportException {
+            int errors = 0;
+            transport.close();
+
+            while (errors < maxRetries) {
+                try {
+                    LOG.debug("Attempting to reconnect...");
+                    transport.open();
+                    LOG.debug("Reconnection successful");
+                    break;
+                } catch (TTransportException e) {
+                    LOG.error("Error while reconnecting:", e);
+                    errors++;
+
+                    if (errors < maxRetries) {
+                        try {
+                            LOG.debug("Sleeping for {} milliseconds before retrying", timeBetweenRetries);
+                            Thread.sleep(timeBetweenRetries);
+                        } catch (InterruptedException e2) {
+                            Thread.currentThread().interrupt();
+                            throw new RuntimeException(e);
+                        }
+                    }
+                }
+            }
+
+            if (errors >= maxRetries) {
+                throw new TTransportException("Failed to reconnect");
+            }
+        }
+
+        @Override
+        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+
+            // With Thrift clients must be instantiated for each different transport session, i.e. server instance.
+            // Hence, using baseClient as lock, only calls towards the same server will be synchronized.
+
+            synchronized (baseClient) {
+
+                LOG.debug("Invoking client method... > method={}, fromThread={}",
+                          method.getName(), Thread.currentThread().getId());
+
+                Object result = null;
+
+                try {
+                    result = method.invoke(baseClient, args);
+
+                } catch (InvocationTargetException e) {
+                    if (e.getTargetException() instanceof TTransportException) {
+                        TTransportException cause = (TTransportException) e.getTargetException();
+
+                        if (RESTARTABLE_CAUSES.contains(cause.getType())) {
+                            reconnectOrThrowException(baseClient.getInputProtocol().getTransport(),
+                                                      maxRetries,
+                                                      timeBetweenRetries);
+                            result = method.invoke(baseClient, args);
+                        }
+                    }
+
+                    if (result == null) {
+                        LOG.debug("Exception while invoking client method: {} > method={}, fromThread={}",
+                                  e, method.getName(), Thread.currentThread().getId());
+                        throw e.getTargetException();
+                    }
+                }
+
+                LOG.debug("Method invoke complete! > method={}, fromThread={}",
+                          method.getName(), Thread.currentThread().getId());
+
+                return result;
+            }
+        }
+    }
+}