Java tutorial
/** * Copyright (c) 2015 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, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.openflowplugin.impl.services; import com.google.common.base.Preconditions; import com.google.common.util.concurrent.Futures; import java.math.BigInteger; import java.util.concurrent.Future; import java.util.concurrent.TimeUnit; import javax.annotation.concurrent.GuardedBy; import org.opendaylight.openflowplugin.api.openflow.connection.ConnectionContext.CONNECTION_STATE; import org.opendaylight.openflowplugin.api.openflow.device.DeviceContext; import org.opendaylight.openflowplugin.api.openflow.device.RequestContextStack; import org.opendaylight.openflowplugin.api.openflow.device.Xid; import org.opendaylight.openflowplugin.impl.role.RoleChangeException; import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeId; import org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.OfHeader; import org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.RoleRequestOutput; import org.opendaylight.yang.gen.v1.urn.opendaylight.role.service.rev150727.OfpRole; import org.opendaylight.yang.gen.v1.urn.opendaylight.role.service.rev150727.SalRoleService; import org.opendaylight.yang.gen.v1.urn.opendaylight.role.service.rev150727.SetRoleInput; import org.opendaylight.yang.gen.v1.urn.opendaylight.role.service.rev150727.SetRoleOutput; import org.opendaylight.yangtools.yang.common.RpcResult; import org.opendaylight.yangtools.yang.common.RpcResultBuilder; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public final class SalRoleServiceImpl extends AbstractSimpleService<SetRoleInput, SetRoleOutput> implements SalRoleService { private static final Logger LOG = LoggerFactory.getLogger(SalRoleServiceImpl.class); private static final BigInteger MAX_GENERATION_ID = new BigInteger("ffffffffffffffff", 16); private static final int MAX_RETRIES = 42; private final DeviceContext deviceContext; private final RoleService roleService; private final NodeId nodeId; private final Short version; @GuardedBy("this") private OfpRole currentRole = OfpRole.NOCHANGE; public SalRoleServiceImpl(final RequestContextStack requestContextStack, final DeviceContext deviceContext) { super(requestContextStack, deviceContext, SetRoleOutput.class); this.deviceContext = Preconditions.checkNotNull(deviceContext); this.roleService = new RoleService(requestContextStack, deviceContext, RoleRequestOutput.class); nodeId = deviceContext.getPrimaryConnectionContext().getNodeId(); version = deviceContext.getPrimaryConnectionContext().getFeatures().getVersion(); } @Override protected OfHeader buildRequest(final Xid xid, final SetRoleInput input) { return null; } @Override public Future<RpcResult<SetRoleOutput>> setRole(final SetRoleInput input) { LOG.info("SetRole called with input:{}", input); synchronized (this) { // compare with last known role and set if different. If they are same, then return. if (currentRole == input.getControllerRole()) { LOG.info("Role to be set is same as the last known role for the device:{}. Hence ignoring.", input.getControllerRole()); return RpcResultBuilder.<SetRoleOutput>success().buildFuture(); } int retryCounter = 0; do { // Check current connection state final CONNECTION_STATE state = deviceContext.getPrimaryConnectionContext().getConnectionState(); switch (state) { case RIP: LOG.info("Device {} has been disconnected", input.getNode()); return Futures.immediateFailedFuture(new Exception(String.format( "Device connection doesn't exist anymore. Primary connection status : %s", state))); case WORKING: // We can proceed break; default: LOG.info("Device {} is in state {}, role change is not allowed", input.getNode(), state); return RpcResultBuilder.<SetRoleOutput>failed().buildFuture(); } LOG.info("Requesting state change to {}", input.getControllerRole()); try { final SetRoleOutput result = tryChangeRole(input.getControllerRole()); LOG.info("setRoleOutput received after roleChangeTask execution:{}", result); currentRole = input.getControllerRole(); return RpcResultBuilder.<SetRoleOutput>success().withResult(result).buildFuture(); } catch (RoleChangeException e) { retryCounter++; LOG.info("Exception in setRole(), will retry: {} times.", MAX_RETRIES - retryCounter, e); } catch (Exception e) { LOG.warn("Unexpected failure to set role on {}", nodeId, e); return Futures.immediateFailedFuture(e); } } while (retryCounter < MAX_RETRIES); } return Futures.immediateFailedFuture(new RoleChangeException( "Set Role failed after " + MAX_RETRIES + "tries on device " + input.getNode().getValue())); } private SetRoleOutput tryChangeRole(final OfpRole role) throws RoleChangeException { LOG.info("RoleChangeTask called on device:{} OFPRole:{}", nodeId.getValue(), role); // we cannot move ahead without having the generation id, so block the thread till we get it. final BigInteger generationId; try { generationId = roleService.getGenerationIdFromDevice(version).get(10, TimeUnit.SECONDS); LOG.info("RoleChangeTask, GenerationIdFromDevice from device is {}", generationId); } catch (Exception e) { LOG.info("Exception in getting generationId for device:{}", nodeId.getValue(), e); throw new RoleChangeException("Exception in getting generationId for device:" + nodeId.getValue(), e); } LOG.info("GenerationId received from device:{} is {}", nodeId.getValue(), generationId); final BigInteger nextGenerationId = getNextGenerationId(generationId); LOG.info("nextGenerationId received from device:{} is {}", nodeId.getValue(), nextGenerationId); final SetRoleOutput setRoleOutput; try { setRoleOutput = roleService.submitRoleChange(role, version, nextGenerationId).get(10, TimeUnit.SECONDS); LOG.info("setRoleOutput after submitRoleChange:{}", setRoleOutput); } catch (Exception e) { LOG.error("Exception in making role change for device", e); throw new RoleChangeException("Exception in making role change for device:" + nodeId.getValue()); } return setRoleOutput; } private static BigInteger getNextGenerationId(final BigInteger generationId) { if (generationId.compareTo(MAX_GENERATION_ID) < 0) { return generationId.add(BigInteger.ONE); } else { return BigInteger.ZERO; } } }