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authorwaqas.ikram <waqas.ikram@ericsson.com>2018-06-05 16:18:01 +0100
committerwaqas.ikram <waqas.ikram@ericsson.com>2018-06-05 16:18:47 +0100
commitf94d7521936e66febee983ee7633aacaaf9d7390 (patch)
treebc93547a9541ca4f868a0f70f6e6d020458a1557 /plugins/plugins-context/context-locking/context-locking-curator
parent37d6fd9069eb30d88c4ad80b5f35099ed173cc13 (diff)
Adding apex plugins/plugins-context modules
Change-Id: I36fc295ffbd22661bf8bd091bfb20ebf6dcc7f5e Issue-ID: POLICY-862 Signed-off-by: waqas.ikram <waqas.ikram@ericsson.com>
Diffstat (limited to 'plugins/plugins-context/context-locking/context-locking-curator')
-rw-r--r--plugins/plugins-context/context-locking/context-locking-curator/pom.xml45
-rw-r--r--plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockFacade.java137
-rw-r--r--plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockManager.java185
-rw-r--r--plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockManagerParameters.java120
-rw-r--r--plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorReentrantReadWriteLock.java90
-rw-r--r--plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/package-info.java27
6 files changed, 604 insertions, 0 deletions
diff --git a/plugins/plugins-context/context-locking/context-locking-curator/pom.xml b/plugins/plugins-context/context-locking/context-locking-curator/pom.xml
new file mode 100644
index 000000000..d5d50e1a1
--- /dev/null
+++ b/plugins/plugins-context/context-locking/context-locking-curator/pom.xml
@@ -0,0 +1,45 @@
+<!--
+ ============LICENSE_START=======================================================
+ Copyright (C) 2018 Ericsson. All rights reserved.
+ ================================================================================
+ 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.
+
+ SPDX-License-Identifier: Apache-2.0
+ ============LICENSE_END=========================================================
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+ <parent>
+ <groupId>org.onap.policy.apex-pdp.plugins.plugins-context.context-locking</groupId>
+ <artifactId>context-locking</artifactId>
+ <version>2.0.0-SNAPSHOT</version>
+ </parent>
+
+ <artifactId>context-locking-curator</artifactId>
+ <name>${project.artifactId}</name>
+ <description>[${project.parent.artifactId}] Plugin for locking using Curator</description>
+
+ <dependencies>
+ <dependency>
+ <groupId>org.apache.curator</groupId>
+ <artifactId>curator-framework</artifactId>
+ <version>4.0.0</version>
+ </dependency>
+ <dependency>
+ <groupId>org.apache.curator</groupId>
+ <artifactId>curator-recipes</artifactId>
+ <version>4.0.0</version>
+ </dependency>
+ </dependencies>
+</project> \ No newline at end of file
diff --git a/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockFacade.java b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockFacade.java
new file mode 100644
index 000000000..928255031
--- /dev/null
+++ b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockFacade.java
@@ -0,0 +1,137 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.plugins.context.locking.curator;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+
+import org.apache.curator.framework.recipes.locks.InterProcessMutex;
+import org.slf4j.ext.XLogger;
+import org.slf4j.ext.XLoggerFactory;
+
+/**
+ * This class provides a facade over the {@link Lock} interface for Curator locks.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class CuratorLockFacade implements Lock {
+ // Logger for this class
+ private static final XLogger LOGGER = XLoggerFactory.getXLogger(CuratorLockFacade.class);
+
+ // The Lock ID
+ private final String lockId;
+
+ // The mutex used for Curator locking
+ private final InterProcessMutex lockMutex;
+
+ /**
+ * Create the lock Facade.
+ *
+ * @param lockMutex The lock mutex behind the facade
+ * @param lockId The ID of the lock
+ */
+ public CuratorLockFacade(final InterProcessMutex lockMutex, final String lockId) {
+ this.lockId = lockId;
+ this.lockMutex = lockMutex;
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see java.util.concurrent.locks.Lock#lock()
+ */
+ @Override
+ public void lock() {
+ try {
+ lockMutex.acquire();
+ } catch (final Exception e) {
+ LOGGER.warn("failed to acquire lock for \"" + lockId, e);
+ }
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see java.util.concurrent.locks.Lock#lockInterruptibly()
+ */
+ @Override
+ public void lockInterruptibly() throws InterruptedException {
+ LOGGER.warn("lockInterruptibly() not supported for \"" + lockId);
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see java.util.concurrent.locks.Lock#tryLock()
+ */
+ @Override
+ public boolean tryLock() {
+ try {
+ lockMutex.acquire();
+ return true;
+ } catch (final Exception e) {
+ LOGGER.warn("failed to acquire lock for \"" + lockId, e);
+ return false;
+ }
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see java.util.concurrent.locks.Lock#tryLock(long, java.util.concurrent.TimeUnit)
+ */
+ @Override
+ public boolean tryLock(final long time, final TimeUnit unit) throws InterruptedException {
+ try {
+ lockMutex.acquire(time, unit);
+ return true;
+ } catch (final Exception e) {
+ LOGGER.warn("failed to acquire lock for \"" + lockId, e);
+ return false;
+ }
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see java.util.concurrent.locks.Lock#unlock()
+ */
+ @Override
+ public void unlock() {
+ try {
+ lockMutex.release();
+ } catch (final Exception e) {
+ LOGGER.warn("failed to release lock for \"" + lockId, e);
+ }
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see java.util.concurrent.locks.Lock#newCondition()
+ */
+ @Override
+ public Condition newCondition() {
+ LOGGER.warn("newCondition() not supported for \"" + lockId);
+ return null;
+ }
+}
diff --git a/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockManager.java b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockManager.java
new file mode 100644
index 000000000..d0cc842fd
--- /dev/null
+++ b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockManager.java
@@ -0,0 +1,185 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.plugins.context.locking.curator;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.ReadWriteLock;
+
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.CuratorFrameworkFactory;
+import org.apache.curator.framework.state.ConnectionState;
+import org.apache.curator.framework.state.ConnectionStateListener;
+import org.apache.curator.retry.ExponentialBackoffRetry;
+import org.apache.curator.utils.CloseableUtils;
+import org.apache.zookeeper.CreateMode;
+import org.onap.policy.apex.context.ContextException;
+import org.onap.policy.apex.context.impl.locking.AbstractLockManager;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.service.ParameterService;
+import org.slf4j.ext.XLogger;
+import org.slf4j.ext.XLoggerFactory;
+
+/**
+ * The Class CuratorLockManager manages the Curator interface towards Zookeeper for administering
+ * the Apex Context Album instance locks..
+ */
+public class CuratorLockManager extends AbstractLockManager {
+ // Logger for this class
+ private static final XLogger LOGGER = XLoggerFactory.getXLogger(CuratorLockManager.class);
+
+ // The Curator framework used for locking
+ private CuratorFramework curatorFramework;
+
+ // The address of the Zookeeper server
+ private String curatorZookeeperAddress;
+
+ /**
+ * Constructor, set up a lock manager that uses Curator locking.
+ *
+ * @throws ContextException On errors connecting to Curator
+ */
+ public CuratorLockManager() throws ContextException {
+ LOGGER.entry("CuratorLockManager(): setting up the Curator lock manager . . .");
+
+ LOGGER.exit("CuratorLockManager(): Curator lock manager set up");
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see org.onap.policy.apex.context.impl.locking.AbstractLockManager#init(org.onap.policy.apex.
+ * model. basicmodel.concepts.AxArtifactKey)
+ */
+ @Override
+ public void init(final AxArtifactKey key) throws ContextException {
+ LOGGER.entry("init(" + key + ")");
+
+ super.init(key);
+
+ // Get the lock manager parameters
+ final CuratorLockManagerParameters lockParameters =
+ ParameterService.getParameters(CuratorLockManagerParameters.class);
+
+ // Check if the curator address has been set
+ curatorZookeeperAddress = lockParameters.getZookeeperAddress();
+ if (curatorZookeeperAddress == null || curatorZookeeperAddress.trim().length() == 0) {
+ LOGGER.warn(
+ "could not set up Curator locking, check if the curator Zookeeper address parameter is set correctly");
+ throw new ContextException(
+ "could not set up Curator locking, check if the curator Zookeeper address parameter is set correctly");
+ }
+
+ // Set up the curator framework we'll use
+ curatorFramework = CuratorFrameworkFactory.builder().connectString(curatorZookeeperAddress)
+ .retryPolicy(new ExponentialBackoffRetry(lockParameters.getZookeeperConnectSleepTime(),
+ lockParameters.getZookeeperContextRetries()))
+ .build();
+
+ // Listen for changes on the Curator connection
+ curatorFramework.getConnectionStateListenable().addListener(new CuratorManagerConnectionStateListener());
+
+ // Start the framework and specify Ephemeral nodes
+ curatorFramework.start();
+
+ // Wait for the connection to be made
+ try {
+ curatorFramework.blockUntilConnected(
+ lockParameters.getZookeeperConnectSleepTime() * lockParameters.getZookeeperContextRetries(),
+ TimeUnit.MILLISECONDS);
+ } catch (final InterruptedException e) {
+ LOGGER.warn("could not connect to Zookeeper server at \"" + curatorZookeeperAddress
+ + "\", wait for connection timed out");
+ throw new ContextException("could not connect to Zookeeper server at \"" + curatorZookeeperAddress
+ + "\", wait for connection timed out");
+ }
+
+ if (!curatorFramework.getZookeeperClient().isConnected()) {
+ LOGGER.warn("could not connect to Zookeeper server at \"" + curatorZookeeperAddress
+ + "\", see error log for details");
+ throw new ContextException("could not connect to Zookeeper server at \"" + curatorZookeeperAddress
+ + "\", see error log for details");
+ }
+
+ // We'll use Ephemeral nodes for locks on the Zookeeper server
+ curatorFramework.create().withMode(CreateMode.EPHEMERAL_SEQUENTIAL);
+
+ LOGGER.exit("init(" + key + "," + lockParameters + ")");
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see
+ * org.onap.policy.apex.core.context.impl.locking.AbstractLockManager#getReentrantReadWriteLock(
+ * java.lang.String)
+ */
+ @Override
+ public ReadWriteLock getReentrantReadWriteLock(final String lockId) throws ContextException {
+ // Check if the framework is active
+ if (curatorFramework != null && curatorFramework.getZookeeperClient().isConnected()) {
+ return new CuratorReentrantReadWriteLock(curatorFramework, "/" + lockId);
+ } else {
+ throw new ContextException("creation of lock using Zookeeper server at \"" + curatorZookeeperAddress
+ + "\", failed, see error log for details");
+ }
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see org.onap.policy.apex.core.context.LockManager#shutdown()
+ */
+ @Override
+ public void shutdown() {
+ if (curatorFramework == null) {
+ return;
+ }
+ CloseableUtils.closeQuietly(curatorFramework);
+ curatorFramework = null;
+ }
+
+ /**
+ * This class is a callback class for state changes on the curator to Zookeeper connection.
+ */
+ private class CuratorManagerConnectionStateListener implements ConnectionStateListener {
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see org.apache.curator.framework.state.ConnectionStateListener#stateChanged(org.apache.
+ * curator.framework.CuratorFramework, org.apache.curator.framework.state.ConnectionState)
+ */
+ @Override
+ public void stateChanged(final CuratorFramework incomngCuratorFramework, final ConnectionState newState) {
+ // Is the state changed for this curator framework?
+ if (!incomngCuratorFramework.equals(curatorFramework)) {
+ return;
+ }
+
+ LOGGER.info("curator state of client \"" + curatorFramework + "\" connected to \"" + curatorZookeeperAddress
+ + "\" changed to " + newState);
+
+ if (newState != ConnectionState.CONNECTED) {
+ shutdown();
+ }
+ }
+ }
+}
diff --git a/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockManagerParameters.java b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockManagerParameters.java
new file mode 100644
index 000000000..9e8d5d2af
--- /dev/null
+++ b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorLockManagerParameters.java
@@ -0,0 +1,120 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.plugins.context.locking.curator;
+
+import org.onap.policy.apex.context.parameters.LockManagerParameters;
+import org.onap.policy.apex.model.basicmodel.service.ParameterService;
+
+/**
+ * Bean class for Curator locking parameters.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class CuratorLockManagerParameters extends LockManagerParameters {
+ // @formatter:off
+ /** The default address used to connect to the Zookeeper server. */
+ public static final String DEFAULT_ZOOKEEPER_ADDRESS = "localhost:2181";
+
+ /** The default sleep time to use when connecting to the Zookeeper server. */
+ public static final int DEFAULT_ZOOKEEPER_CONNECT_SLEEP_TIME = 1000;
+
+ /** The default number of times to retry failed connections to the Zookeeper server. */
+ public static final int DEFAULT_ZOOKEEPER_CONNECT_RETRIES = 3;
+
+ // Curator parameters
+ private String zookeeperAddress = DEFAULT_ZOOKEEPER_ADDRESS;
+ private int zookeeperConnectSleepTime = DEFAULT_ZOOKEEPER_CONNECT_SLEEP_TIME;
+ private int zookeeperContextRetries = DEFAULT_ZOOKEEPER_CONNECT_RETRIES;
+ // @formatter:on
+
+ /**
+ * The Constructor.
+ */
+ public CuratorLockManagerParameters() {
+ super(CuratorLockManagerParameters.class.getCanonicalName());
+ ParameterService.registerParameters(CuratorLockManagerParameters.class, this);
+ }
+
+ /**
+ * Gets the zookeeper address.
+ *
+ * @return the zookeeper address
+ */
+ public String getZookeeperAddress() {
+ return zookeeperAddress;
+ }
+
+ /**
+ * Sets the zookeeper address.
+ *
+ * @param zookeeperAddress the zookeeper address
+ */
+ public void setZookeeperAddress(final String zookeeperAddress) {
+ this.zookeeperAddress = zookeeperAddress;
+ }
+
+ /**
+ * Gets the zookeeper connect sleep time.
+ *
+ * @return the zookeeper connect sleep time
+ */
+ public int getZookeeperConnectSleepTime() {
+ return zookeeperConnectSleepTime;
+ }
+
+ /**
+ * Sets the zookeeper connect sleep time.
+ *
+ * @param zookeeperConnectSleepTime the zookeeper connect sleep time
+ */
+ public void setZookeeperConnectSleepTime(final int zookeeperConnectSleepTime) {
+ this.zookeeperConnectSleepTime = zookeeperConnectSleepTime;
+ }
+
+ /**
+ * Gets the zookeeper context retries.
+ *
+ * @return the zookeeper context retries
+ */
+ public int getZookeeperContextRetries() {
+ return zookeeperContextRetries;
+ }
+
+ /**
+ * Sets the zookeeper context retries.
+ *
+ * @param zookeeperContextRetries the zookeeper context retries
+ */
+ public void setZookeeperContextRetries(final int zookeeperContextRetries) {
+ this.zookeeperContextRetries = zookeeperContextRetries;
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see org.onap.policy.apex.context.parameters.LockManagerParameters#toString()
+ */
+ @Override
+ public String toString() {
+ return "CuratorLockManagerParameters [zookeeperAddress=" + zookeeperAddress + ", zookeeperConnectSleepTime="
+ + zookeeperConnectSleepTime + ", zookeeperContextRetries=" + zookeeperContextRetries + "]";
+ }
+}
diff --git a/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorReentrantReadWriteLock.java b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorReentrantReadWriteLock.java
new file mode 100644
index 000000000..22bf5e596
--- /dev/null
+++ b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/CuratorReentrantReadWriteLock.java
@@ -0,0 +1,90 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.plugins.context.locking.curator;
+
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReadWriteLock;
+
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.recipes.locks.InterProcessReadWriteLock;
+
+/**
+ * This class maps a Curator {@link InterProcessReadWriteLock} to a Java {@link ReadWriteLock}.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class CuratorReentrantReadWriteLock implements ReadWriteLock {
+ // The Lock ID
+ private final String lockID;
+
+ // The Curator lock
+ private final InterProcessReadWriteLock curatorReadWriteLock;
+
+ // The Curator Lock facades for read and write locks
+ private final CuratorLockFacade readLockFacade;
+ private final CuratorLockFacade writeLockFacade;
+
+ /**
+ * Create a Curator lock.
+ *
+ * @param curatorFramework the Curator framework to use to create the lock
+ * @param lockId The unique ID of the lock.
+ */
+ public CuratorReentrantReadWriteLock(final CuratorFramework curatorFramework, final String lockId) {
+ lockID = lockId;
+
+ // Create the Curator lock
+ curatorReadWriteLock = new InterProcessReadWriteLock(curatorFramework, lockId);
+
+ // Create the lock facades
+ readLockFacade = new CuratorLockFacade(curatorReadWriteLock.readLock(), lockId);
+ writeLockFacade = new CuratorLockFacade(curatorReadWriteLock.writeLock(), lockId);
+ }
+
+ /**
+ * Get the lock Id of the lock.
+ *
+ * @return the lock ID
+ */
+ public String getLockID() {
+ return lockID;
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see java.util.concurrent.locks.ReadWriteLock#readLock()
+ */
+ @Override
+ public Lock readLock() {
+ return readLockFacade;
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see java.util.concurrent.locks.ReadWriteLock#writeLock()
+ */
+ @Override
+ public Lock writeLock() {
+ return writeLockFacade;
+ }
+}
diff --git a/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/package-info.java b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/package-info.java
new file mode 100644
index 000000000..d867c396a
--- /dev/null
+++ b/plugins/plugins-context/context-locking/context-locking-curator/src/main/java/org/onap/policy/apex/plugins/context/locking/curator/package-info.java
@@ -0,0 +1,27 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+/**
+ * Implements locking on context items in APEX context albums using
+ * <a href="http://curator.apache.org/">Curator</a> centralized locking.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+package org.onap.policy.apex.plugins.context.locking.curator;