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-rw-r--r--policy-management/src/main/java/org/onap/policy/drools/features/PolicyEngineFeatureApi.java23
-rw-r--r--policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngine.java33
-rw-r--r--policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineManager.java139
-rw-r--r--policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockManager.java426
-rw-r--r--policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockManagerException.java34
-rw-r--r--policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockProperties.java52
6 files changed, 704 insertions, 3 deletions
diff --git a/policy-management/src/main/java/org/onap/policy/drools/features/PolicyEngineFeatureApi.java b/policy-management/src/main/java/org/onap/policy/drools/features/PolicyEngineFeatureApi.java
index fe31eb50..87001ad6 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/features/PolicyEngineFeatureApi.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/features/PolicyEngineFeatureApi.java
@@ -23,6 +23,7 @@ package org.onap.policy.drools.features;
import java.util.Properties;
import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
import org.onap.policy.common.utils.services.OrderedService;
+import org.onap.policy.drools.core.lock.PolicyResourceLockManager;
import org.onap.policy.drools.protocol.configuration.PdpdConfiguration;
import org.onap.policy.drools.system.PolicyEngine;
@@ -271,4 +272,26 @@ public interface PolicyEngineFeatureApi extends OrderedService {
default boolean afterOpen(PolicyEngine engine) {
return false;
}
+
+ /**
+ * Called before the PolicyEngine creates a lock manager.
+ *
+ * @return a lock manager if this feature intercepts and takes ownership of the
+ * operation preventing the invocation of lower priority features. Null,
+ * otherwise
+ */
+ default PolicyResourceLockManager beforeCreateLockManager(PolicyEngine engine, Properties properties) {
+ return null;
+ }
+
+ /**
+ * Called after the PolicyEngine creates a lock manager.
+ *
+ * @return True if this feature intercepts and takes ownership of the operation
+ * preventing the invocation of lower priority features. False, otherwise
+ */
+ default boolean afterCreateLockManager(PolicyEngine engine, Properties properties,
+ PolicyResourceLockManager lockManager) {
+ return false;
+ }
}
diff --git a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngine.java b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngine.java
index 653ff72e..cb0749d9 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngine.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngine.java
@@ -22,6 +22,7 @@ package org.onap.policy.drools.system;
import java.util.List;
import java.util.Properties;
+import java.util.concurrent.ScheduledExecutorService;
import org.onap.policy.common.capabilities.Lockable;
import org.onap.policy.common.capabilities.Startable;
import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
@@ -29,6 +30,8 @@ import org.onap.policy.common.endpoints.event.comm.TopicListener;
import org.onap.policy.common.endpoints.event.comm.TopicSink;
import org.onap.policy.common.endpoints.event.comm.TopicSource;
import org.onap.policy.common.endpoints.http.server.HttpServletServer;
+import org.onap.policy.drools.core.lock.Lock;
+import org.onap.policy.drools.core.lock.LockCallback;
import org.onap.policy.drools.features.PolicyEngineFeatureApi;
import org.onap.policy.drools.protocol.configuration.ControllerConfiguration;
import org.onap.policy.drools.protocol.configuration.PdpdConfiguration;
@@ -198,6 +201,11 @@ public interface PolicyEngine extends Startable, Lockable, TopicListener {
List<HttpServletServer> getHttpServers();
/**
+ * Gets a thread pool that can be used to execute background tasks.
+ */
+ ScheduledExecutorService getExecutorService();
+
+ /**
* get properties configuration.
*
* @return properties objects
@@ -280,6 +288,31 @@ public interface PolicyEngine extends Startable, Lockable, TopicListener {
boolean deliver(CommInfrastructure busType, String topic, String event);
/**
+ * Requests a lock on a resource. Typically, the lock is not immediately granted,
+ * though a "lock" object is always returned. Once the lock has been granted (or
+ * denied), the callback will be invoked to indicate the result.
+ *
+ * <p/>
+ * Notes:
+ * <dl>
+ * <li>The callback may be invoked <i>before</i> this method returns</li>
+ * <li>The implementation need not honor waitForLock={@code true}</li>
+ * </dl>
+ *
+ * @param resourceId identifier of the resource to be locked
+ * @param ownerKey information identifying the owner requesting the lock
+ * @param holdSec amount of time, in seconds, for which the lock should be held once
+ * it has been granted, after which it will automatically be released
+ * @param callback callback to be invoked once the lock is granted, or subsequently
+ * lost; must not be {@code null}
+ * @param waitForLock {@code true} to wait for the lock, if it is currently locked,
+ * {@code false} otherwise
+ * @return a new lock
+ */
+ public Lock createLock(String resourceId, String ownerKey, int holdSec, LockCallback callback,
+ boolean waitForLock);
+
+ /**
* Invoked when the host goes into the active state.
*/
void activate();
diff --git a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineManager.java b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineManager.java
index 766848c6..c924fd69 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineManager.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineManager.java
@@ -24,7 +24,6 @@ import static org.onap.policy.drools.system.PolicyEngineConstants.TELEMETRY_SERV
import static org.onap.policy.drools.system.PolicyEngineConstants.TELEMETRY_SERVER_DEFAULT_NAME;
import static org.onap.policy.drools.system.PolicyEngineConstants.TELEMETRY_SERVER_DEFAULT_PORT;
-import com.att.aft.dme2.internal.apache.commons.lang3.StringUtils;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.gson.Gson;
@@ -32,11 +31,16 @@ import com.google.gson.GsonBuilder;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.BiConsumer;
import java.util.function.Consumer;
import java.util.stream.Stream;
+import lombok.AccessLevel;
import lombok.Getter;
+import lombok.NonNull;
+import org.apache.commons.lang.StringUtils;
import org.onap.policy.common.endpoints.event.comm.Topic;
import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
import org.onap.policy.common.endpoints.event.comm.TopicEndpoint;
@@ -54,6 +58,9 @@ import org.onap.policy.drools.controller.DroolsController;
import org.onap.policy.drools.controller.DroolsControllerConstants;
import org.onap.policy.drools.core.PolicyContainer;
import org.onap.policy.drools.core.jmx.PdpJmxListener;
+import org.onap.policy.drools.core.lock.Lock;
+import org.onap.policy.drools.core.lock.LockCallback;
+import org.onap.policy.drools.core.lock.PolicyResourceLockManager;
import org.onap.policy.drools.features.PolicyControllerFeatureApi;
import org.onap.policy.drools.features.PolicyControllerFeatureApiConstants;
import org.onap.policy.drools.features.PolicyEngineFeatureApi;
@@ -67,6 +74,7 @@ import org.onap.policy.drools.protocol.configuration.ControllerConfiguration;
import org.onap.policy.drools.protocol.configuration.PdpdConfiguration;
import org.onap.policy.drools.server.restful.RestManager;
import org.onap.policy.drools.server.restful.aaf.AafTelemetryAuthFilter;
+import org.onap.policy.drools.system.internal.SimpleLockManager;
import org.onap.policy.drools.utils.PropertyUtil;
import org.onap.policy.drools.utils.logging.LoggerUtil;
import org.onap.policy.drools.utils.logging.MdcTransaction;
@@ -78,7 +86,6 @@ import org.slf4j.LoggerFactory;
* Policy Engine Manager Implementation.
*/
class PolicyEngineManager implements PolicyEngine {
-
/**
* String literals.
*/
@@ -88,6 +95,9 @@ class PolicyEngineManager implements PolicyEngine {
private static final String ENGINE_STOPPED_MSG = "Policy Engine is stopped";
private static final String ENGINE_LOCKED_MSG = "Policy Engine is locked";
+ public static final String EXECUTOR_THREAD_PROP = "executor.threads";
+ protected static final int DEFAULT_EXECUTOR_THREADS = 5;
+
/**
* logger.
*/
@@ -134,6 +144,17 @@ class PolicyEngineManager implements PolicyEngine {
private List<HttpServletServer> httpServers = new ArrayList<>();
/**
+ * Thread pool used to execute background tasks.
+ */
+ private ScheduledExecutorService executorService = null;
+
+ /**
+ * Lock manager used to create locks.
+ */
+ @Getter(AccessLevel.PROTECTED)
+ private PolicyResourceLockManager lockManager = null;
+
+ /**
* gson parser to decode configuration requests.
*/
private final Gson decoder = new GsonBuilder().disableHtmlEscaping().create();
@@ -214,6 +235,53 @@ class PolicyEngineManager implements PolicyEngine {
}
@Override
+ @JsonIgnore
+ @GsonJsonIgnore
+ public ScheduledExecutorService getExecutorService() {
+ return executorService;
+ }
+
+ private ScheduledExecutorService makeExecutorService(Properties properties) {
+ int nthreads = DEFAULT_EXECUTOR_THREADS;
+ try {
+ nthreads = Integer.valueOf(
+ properties.getProperty(EXECUTOR_THREAD_PROP, String.valueOf(DEFAULT_EXECUTOR_THREADS)));
+
+ } catch (NumberFormatException e) {
+ logger.error("invalid number for " + EXECUTOR_THREAD_PROP + " property", e);
+ }
+
+ return makeScheduledExecutor(nthreads);
+ }
+
+ private void createLockManager(Properties properties) {
+ for (PolicyEngineFeatureApi feature : getEngineProviders()) {
+ try {
+ this.lockManager = feature.beforeCreateLockManager(this, properties);
+ if (this.lockManager != null) {
+ return;
+ }
+ } catch (RuntimeException e) {
+ logger.error("{}: feature {} before-create-lock-manager failure because of {}", this,
+ feature.getClass().getName(), e.getMessage(), e);
+ }
+ }
+
+ try {
+ this.lockManager = new SimpleLockManager(this, properties);
+ } catch (RuntimeException e) {
+ logger.error("{}: cannot create simple lock manager because of {}", this, e.getMessage(), e);
+ this.lockManager = new SimpleLockManager(this, new Properties());
+ }
+
+ /* policy-engine dispatch post operation hook */
+ FeatureApiUtils.apply(getEngineProviders(),
+ feature -> feature.afterCreateLockManager(this, properties, this.lockManager),
+ (feature, ex) -> logger.error("{}: feature {} after-create-lock-manager failure because of {}",
+ this, feature.getClass().getName(), ex.getMessage(), ex));
+ }
+
+ @Override
public synchronized void configure(Properties properties) {
if (properties == null) {
@@ -257,6 +325,10 @@ class PolicyEngineManager implements PolicyEngine {
logger.error("{}: add-http-servers failed", this, e);
}
+ executorService = makeExecutorService(properties);
+
+ createLockManager(properties);
+
/* policy-engine dispatch post configure hook */
FeatureApiUtils.apply(getEngineProviders(),
feature -> feature.afterConfigure(this),
@@ -499,6 +571,13 @@ class PolicyEngineManager implements PolicyEngine {
AtomicReference<Boolean> success = new AtomicReference<>(true);
+ try {
+ success.compareAndSet(true, this.lockManager.start());
+ } catch (final RuntimeException e) {
+ logger.warn("{}: cannot start lock manager because of {}", this, e.getMessage(), e);
+ success.set(false);
+ }
+
/* Start Policy Engine exclusively-owned (unmanaged) http servers */
attempt(success, this.httpServers,
@@ -639,9 +718,16 @@ class PolicyEngineManager implements PolicyEngine {
(item, ex) -> logger.error("{}: cannot stop http-server {} because of {}", this, item,
ex.getMessage(), ex));
+ try {
+ success.compareAndSet(true, this.lockManager.stop());
+ } catch (final RuntimeException e) {
+ logger.warn("{}: cannot stop lock manager because of {}", this, e.getMessage(), e);
+ success.set(false);
+ }
+
// stop JMX?
- /* policy-engine dispatch pre stop hook */
+ /* policy-engine dispatch post stop hook */
FeatureApiUtils.apply(getEngineProviders(),
feature -> feature.afterStop(this),
(feature, ex) -> logger.error("{}: feature {} after-stop failure because of {}", this,
@@ -688,6 +774,14 @@ class PolicyEngineManager implements PolicyEngine {
getTopicEndpointManager().shutdown();
getServletFactory().destroy();
+ try {
+ this.lockManager.shutdown();
+ } catch (final RuntimeException e) {
+ logger.warn("{}: cannot shutdown lock manager because of {}", this, e.getMessage(), e);
+ }
+
+ executorService.shutdownNow();
+
// Stop the JMX listener
stopPdpJmxListener();
@@ -806,6 +900,13 @@ class PolicyEngineManager implements PolicyEngine {
success = getTopicEndpointManager().lock() && success;
+ try {
+ success = (this.lockManager == null || this.lockManager.lock()) && success;
+ } catch (final RuntimeException e) {
+ logger.warn("{}: cannot lock() lock manager because of {}", this, e.getMessage(), e);
+ success = false;
+ }
+
/* policy-engine dispatch post lock hook */
FeatureApiUtils.apply(getEngineProviders(),
feature -> feature.afterLock(this),
@@ -833,6 +934,14 @@ class PolicyEngineManager implements PolicyEngine {
this.locked = false;
boolean success = true;
+
+ try {
+ success = (this.lockManager == null || this.lockManager.unlock()) && success;
+ } catch (final RuntimeException e) {
+ logger.warn("{}: cannot unlock() lock manager because of {}", this, e.getMessage(), e);
+ success = false;
+ }
+
final List<PolicyController> controllers = getControllerFactory().inventory();
for (final PolicyController controller : controllers) {
try {
@@ -1167,6 +1276,21 @@ class PolicyEngineManager implements PolicyEngine {
feature.getClass().getName(), ex.getMessage(), ex));
}
+ @Override
+ public Lock createLock(@NonNull String resourceId, @NonNull String ownerKey, int holdSec,
+ @NonNull LockCallback callback, boolean waitForLock) {
+
+ if (holdSec < 0) {
+ throw new IllegalArgumentException("holdSec is negative");
+ }
+
+ if (lockManager == null) {
+ throw new IllegalStateException("lock manager has not been initialized");
+ }
+
+ return lockManager.createLock(resourceId, ownerKey, holdSec, callback, waitForLock);
+ }
+
private boolean controllerConfig(PdpdConfiguration config) {
/* only this one supported for now */
final List<ControllerConfiguration> configControllers = config.getControllers();
@@ -1234,4 +1358,13 @@ class PolicyEngineManager implements PolicyEngine {
protected PolicyEngine getPolicyEngine() {
return PolicyEngineConstants.getManager();
}
+
+ protected ScheduledExecutorService makeScheduledExecutor(int nthreads) {
+ ScheduledThreadPoolExecutor exsvc = new ScheduledThreadPoolExecutor(nthreads);
+ exsvc.setContinueExistingPeriodicTasksAfterShutdownPolicy(false);
+ exsvc.setExecuteExistingDelayedTasksAfterShutdownPolicy(false);
+ exsvc.setRemoveOnCancelPolicy(true);
+
+ return exsvc;
+ }
}
diff --git a/policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockManager.java b/policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockManager.java
new file mode 100644
index 00000000..f5163e9b
--- /dev/null
+++ b/policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockManager.java
@@ -0,0 +1,426 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.system.internal;
+
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Properties;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.Setter;
+import org.onap.policy.common.utils.properties.exception.PropertyException;
+import org.onap.policy.common.utils.time.CurrentTime;
+import org.onap.policy.drools.core.lock.AlwaysFailLock;
+import org.onap.policy.drools.core.lock.Lock;
+import org.onap.policy.drools.core.lock.LockCallback;
+import org.onap.policy.drools.core.lock.LockImpl;
+import org.onap.policy.drools.core.lock.LockState;
+import org.onap.policy.drools.core.lock.PolicyResourceLockManager;
+import org.onap.policy.drools.system.PolicyEngine;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * Simple implementation of the Lock Feature. Locks do not span across instances of this
+ * object (i.e., locks do not span across servers).
+ *
+ * <p/>
+ * Note: this implementation does <i>not</i> honor the waitForLocks={@code true}
+ * parameter.
+ *
+ * <p/>
+ * When a lock is deserialized, it will not initially appear in this feature's map; it
+ * will be added to the map once free() or extend() is invoked, provided there isn't
+ * already an entry.
+ */
+public class SimpleLockManager implements PolicyResourceLockManager {
+
+ private static final Logger logger = LoggerFactory.getLogger(SimpleLockManager.class);
+
+ private static final String NOT_LOCKED_MSG = "not locked";
+ private static final String LOCK_LOST_MSG = "lock lost";
+
+ /**
+ * Provider of current time. May be overridden by junit tests.
+ */
+ private static CurrentTime currentTime = new CurrentTime();
+
+ @Getter(AccessLevel.PROTECTED)
+ @Setter(AccessLevel.PROTECTED)
+ private static SimpleLockManager latestInstance = null;
+
+
+ /**
+ * Engine with which this manager is associated.
+ */
+ private final PolicyEngine engine;
+
+ /**
+ * Feature properties.
+ */
+ private final SimpleLockProperties featProps;
+
+ /**
+ * Maps a resource to the lock that owns it.
+ */
+ private final Map<String, SimpleLock> resource2lock = new ConcurrentHashMap<>();
+
+ /**
+ * Thread pool used to check for lock expiration and to notify owners when locks are
+ * lost.
+ */
+ private ScheduledExecutorService exsvc = null;
+
+ /**
+ * Used to cancel the expiration checker on shutdown.
+ */
+ private ScheduledFuture<?> checker = null;
+
+
+ /**
+ * Constructs the object.
+ *
+ * @param engine engine with which this manager is associated
+ * @param properties properties used to configure the manager
+ */
+ public SimpleLockManager(PolicyEngine engine, Properties properties) {
+ try {
+ this.engine = engine;
+ this.featProps = new SimpleLockProperties(properties);
+
+ } catch (PropertyException e) {
+ throw new SimpleLockManagerException(e);
+ }
+ }
+
+ @Override
+ public boolean isAlive() {
+ return (checker != null);
+ }
+
+ @Override
+ public boolean start() {
+ if (checker != null) {
+ return false;
+ }
+
+ exsvc = getThreadPool();
+
+ checker = exsvc.scheduleWithFixedDelay(this::checkExpired, featProps.getExpireCheckSec(),
+ featProps.getExpireCheckSec(), TimeUnit.SECONDS);
+
+ setLatestInstance(this);
+
+ return true;
+ }
+
+ /**
+ * Stops the expiration checker. Does <i>not</i> invoke any lock call-backs.
+ */
+ @Override
+ public synchronized boolean stop() {
+ exsvc = null;
+
+ if (checker == null) {
+ return false;
+ }
+
+ ScheduledFuture<?> checker2 = checker;
+ checker = null;
+
+ checker2.cancel(true);
+
+ return true;
+ }
+
+ @Override
+ public void shutdown() {
+ stop();
+ }
+
+ @Override
+ public boolean isLocked() {
+ return false;
+ }
+
+ @Override
+ public boolean lock() {
+ return true;
+ }
+
+ @Override
+ public boolean unlock() {
+ return true;
+ }
+
+ @Override
+ public Lock createLock(String resourceId, String ownerKey, int holdSec, LockCallback callback,
+ boolean waitForLock) {
+
+ if (latestInstance != this) {
+ AlwaysFailLock lock = new AlwaysFailLock(resourceId, ownerKey, holdSec, callback);
+ lock.notifyUnavailable();
+ return lock;
+ }
+
+ SimpleLock lock = makeLock(LockState.WAITING, resourceId, ownerKey, holdSec, callback);
+
+ SimpleLock existingLock = resource2lock.putIfAbsent(resourceId, lock);
+
+ if (existingLock == null) {
+ lock.grant();
+ } else {
+ lock.deny("resource is busy");
+ }
+
+ return lock;
+ }
+
+ /**
+ * Checks for expired locks.
+ */
+ private void checkExpired() {
+ long currentMs = currentTime.getMillis();
+ logger.info("checking for expired locks at {}", currentMs);
+
+ /*
+ * Could do this via an iterator, but using compute() guarantees that the lock
+ * doesn't get extended while it's being removed from the map.
+ */
+ for (Entry<String, SimpleLock> ent : resource2lock.entrySet()) {
+ if (!ent.getValue().expired(currentMs)) {
+ continue;
+ }
+
+ AtomicReference<SimpleLock> lockref = new AtomicReference<>(null);
+
+ resource2lock.computeIfPresent(ent.getKey(), (resourceId, lock) -> {
+ if (lock.expired(currentMs)) {
+ lockref.set(lock);
+ return null;
+ }
+
+ return lock;
+ });
+
+ SimpleLock lock = lockref.get();
+ if (lock != null) {
+ lock.deny("lock expired");
+ }
+ }
+ }
+
+ /**
+ * Simple Lock implementation.
+ */
+ public static class SimpleLock extends LockImpl {
+ private static final long serialVersionUID = 1L;
+
+ /**
+ * Time, in milliseconds, when the lock expires.
+ */
+ @Getter
+ private long holdUntilMs;
+
+ /**
+ * Feature containing this lock. May be {@code null} until the feature is
+ * identified. Note: this can only be null if the lock has been de-serialized.
+ */
+ private transient SimpleLockManager feature;
+
+ /**
+ * Constructs the object.
+ */
+ public SimpleLock() {
+ this.holdUntilMs = 0;
+ this.feature = null;
+ }
+
+ /**
+ * Constructs the object.
+ *
+ * @param state initial state of the lock
+ * @param resourceId identifier of the resource to be locked
+ * @param ownerKey information identifying the owner requesting the lock
+ * @param holdSec amount of time, in seconds, for which the lock should be held,
+ * after which it will automatically be released
+ * @param callback callback to be invoked once the lock is granted, or
+ * subsequently lost; must not be {@code null}
+ * @param feature feature containing this lock
+ */
+ public SimpleLock(LockState state, String resourceId, String ownerKey, int holdSec, LockCallback callback,
+ SimpleLockManager feature) {
+ super(state, resourceId, ownerKey, holdSec, callback);
+ this.feature = feature;
+ }
+
+ /**
+ * Determines if the owner's lock has expired.
+ *
+ * @param currentMs current time, in milliseconds
+ * @return {@code true} if the owner's lock has expired, {@code false} otherwise
+ */
+ public boolean expired(long currentMs) {
+ return (holdUntilMs <= currentMs);
+ }
+
+ /**
+ * Grants this lock. The notification is <i>always</i> invoked via a background
+ * thread.
+ */
+ protected synchronized void grant() {
+ if (isUnavailable()) {
+ return;
+ }
+
+ setState(LockState.ACTIVE);
+ holdUntilMs = currentTime.getMillis() + TimeUnit.SECONDS.toMillis(getHoldSec());
+
+ logger.info("lock granted: {}", this);
+
+ feature.exsvc.execute(this::notifyAvailable);
+ }
+
+ /**
+ * Permanently denies this lock. The notification is invoked via a background
+ * thread, if a feature instance is attached, otherwise it uses the foreground
+ * thread.
+ *
+ * @param reason the reason the lock was denied
+ */
+ protected void deny(String reason) {
+ synchronized (this) {
+ setState(LockState.UNAVAILABLE);
+ }
+
+ logger.info("{}: {}", reason, this);
+
+ if (feature == null) {
+ notifyUnavailable();
+
+ } else {
+ feature.exsvc.execute(this::notifyUnavailable);
+ }
+ }
+
+ @Override
+ public boolean free() {
+ // do a quick check of the state
+ if (isUnavailable()) {
+ return false;
+ }
+
+ logger.info("releasing lock: {}", this);
+
+ if (!attachFeature()) {
+ setState(LockState.UNAVAILABLE);
+ return false;
+ }
+
+ AtomicBoolean result = new AtomicBoolean(false);
+
+ feature.resource2lock.computeIfPresent(getResourceId(), (resourceId, curlock) -> {
+
+ if (curlock == this) {
+ // this lock was the owner - resource is now available
+ result.set(true);
+ setState(LockState.UNAVAILABLE);
+ return null;
+
+ } else {
+ return curlock;
+ }
+ });
+
+ return result.get();
+ }
+
+ @Override
+ public void extend(int holdSec, LockCallback callback) {
+ if (holdSec < 0) {
+ throw new IllegalArgumentException("holdSec is negative");
+ }
+
+ setHoldSec(holdSec);
+ setCallback(callback);
+
+ // do a quick check of the state
+ if (isUnavailable() || !attachFeature()) {
+ deny(LOCK_LOST_MSG);
+ return;
+ }
+
+ if (feature.resource2lock.get(getResourceId()) == this) {
+ grant();
+ } else {
+ deny(NOT_LOCKED_MSG);
+ }
+ }
+
+ /**
+ * Attaches to the feature instance, if not already attached.
+ *
+ * @return {@code true} if the lock is now attached to a feature, {@code false}
+ * otherwise
+ */
+ private synchronized boolean attachFeature() {
+ if (feature != null) {
+ // already attached
+ return true;
+ }
+
+ feature = latestInstance;
+ if (feature == null) {
+ logger.warn("no feature yet for {}", this);
+ return false;
+ }
+
+ // put this lock into the map
+ feature.resource2lock.putIfAbsent(getResourceId(), this);
+
+ return true;
+ }
+
+ @Override
+ public String toString() {
+ return "SimpleLock [state=" + getState() + ", resourceId=" + getResourceId() + ", ownerKey=" + getOwnerKey()
+ + ", holdSec=" + getHoldSec() + ", holdUntilMs=" + holdUntilMs + "]";
+ }
+ }
+
+ // these may be overridden by junit tests
+
+ protected ScheduledExecutorService getThreadPool() {
+ return engine.getExecutorService();
+ }
+
+ protected SimpleLock makeLock(LockState waiting, String resourceId, String ownerKey, int holdSec,
+ LockCallback callback) {
+ return new SimpleLock(waiting, resourceId, ownerKey, holdSec, callback, this);
+ }
+}
diff --git a/policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockManagerException.java b/policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockManagerException.java
new file mode 100644
index 00000000..ff02f39e
--- /dev/null
+++ b/policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockManagerException.java
@@ -0,0 +1,34 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.system.internal;
+
+public class SimpleLockManagerException extends RuntimeException {
+ private static final long serialVersionUID = 1L;
+
+ /**
+ * Constructor.
+ *
+ * @param ex exception to be wrapped
+ */
+ public SimpleLockManagerException(Exception ex) {
+ super(ex);
+ }
+}
diff --git a/policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockProperties.java b/policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockProperties.java
new file mode 100644
index 00000000..0d1ca89b
--- /dev/null
+++ b/policy-management/src/main/java/org/onap/policy/drools/system/internal/SimpleLockProperties.java
@@ -0,0 +1,52 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.system.internal;
+
+import java.util.Properties;
+import lombok.Getter;
+import lombok.Setter;
+import org.onap.policy.common.utils.properties.BeanConfigurator;
+import org.onap.policy.common.utils.properties.Property;
+import org.onap.policy.common.utils.properties.exception.PropertyException;
+
+
+@Getter
+@Setter
+public class SimpleLockProperties {
+ public static final String PREFIX = "simple.locking.";
+ public static final String EXPIRE_CHECK_SEC = PREFIX + "expire.check.seconds";
+
+ /**
+ * Time, in seconds, to wait between checks for expired locks.
+ */
+ @Property(name = EXPIRE_CHECK_SEC, defaultValue = "900")
+ private int expireCheckSec;
+
+ /**
+ * Constructs the object, populating fields from the properties.
+ *
+ * @param props properties from which to configure this
+ * @throws PropertyException if an error occurs
+ */
+ public SimpleLockProperties(Properties props) throws PropertyException {
+ new BeanConfigurator().configureFromProperties(this, props);
+ }
+}