Refactor common code from UsecasesEventManager

Created ClEventManagerWithSteps, as a subclass of
ControlLoopEventManager.  It contains the "Steps" to be performed and
also deals with outcomes.
Created ClEventManagerWithEvent, as a subclass of that.  It contains a
VirtualControlLoopEvent object, and uses that to populate data used by
the superclass.
Updates per review comments:
- made loadPolicy() protected
- refactored another level to manage operation outcomes

Issue-ID: POLICY-3262
Change-Id: Ibf5dd114746ae26e04fe37d562273fc81dd8cfbe
Signed-off-by: Jim Hahn <jrh3@att.com>

6 files changed, 2032 insertions, 0 deletions

diff --git a/controlloop/common/eventmanager/src/main/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithEvent.java b/controlloop/common/eventmanager/src/main/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithEvent.java
new file mode 100644
index 000000000..db7ec1d93
--- /dev/null
+++ b/controlloop/common/eventmanager/src/main/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithEvent.java
@@ -0,0 +1,200 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2021 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.controlloop.eventmanager;
+
+import java.util.HashMap;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.Setter;
+import org.apache.commons.lang3.StringUtils;
+import org.drools.core.WorkingMemory;
+import org.onap.policy.controlloop.ControlLoopEventStatus;
+import org.onap.policy.controlloop.ControlLoopException;
+import org.onap.policy.controlloop.ControlLoopResponse;
+import org.onap.policy.controlloop.VirtualControlLoopEvent;
+import org.onap.policy.controlloop.VirtualControlLoopNotification;
+import org.onap.policy.controlloop.actorserviceprovider.OperationOutcome;
+import org.onap.policy.controlloop.drl.legacy.ControlLoopParams;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Manager for a single control loop event. Once this has been created, the event can be
+ * retracted from working memory.
+ */
+public abstract class ClEventManagerWithEvent<T extends Step> extends ClEventManagerWithOutcome<T>
+                implements StepContext {
+
+    private static final Logger logger = LoggerFactory.getLogger(ClEventManagerWithEvent.class);
+    private static final long serialVersionUID = -1216568161322872641L;
+
+    public enum NewEventStatus {
+        FIRST_ONSET, SUBSEQUENT_ONSET, FIRST_ABATEMENT, SUBSEQUENT_ABATEMENT, SYNTAX_ERROR
+    }
+
+    @Getter
+    private final VirtualControlLoopEvent event;
+
+    @Getter
+    @Setter(AccessLevel.PROTECTED)
+    private VirtualControlLoopEvent abatement = null;
+
+
+    /**
+     * Constructs the object.
+     *
+     * @param params control loop parameters
+     * @param event event to be managed by this object
+     * @param workMem working memory to update if this changes
+     * @throws ControlLoopException if the event is invalid or if a YAML processor cannot
+     *         be created
+     */
+    public ClEventManagerWithEvent(ControlLoopParams params, VirtualControlLoopEvent event, WorkingMemory workMem)
+                    throws ControlLoopException {
+
+        super(params, event.getRequestId(), workMem);
+
+        checkEventSyntax(event);
+
+        this.event = event;
+    }
+
+    @Override
+    protected void populateNotification(VirtualControlLoopNotification notif) {
+        super.populateNotification(notif);
+
+        notif.setClosedLoopControlName(event.getClosedLoopControlName());
+        notif.setRequestId(event.getRequestId());
+        notif.setClosedLoopEventClient(event.getClosedLoopEventClient());
+        notif.setTargetType(event.getTargetType());
+        notif.setTarget(event.getTarget());
+
+        if (event.getAai() != null) {
+            notif.setAai(new HashMap<>(event.getAai()));
+        }
+        notif.setClosedLoopAlarmStart(event.getClosedLoopAlarmStart());
+        notif.setClosedLoopAlarmEnd(event.getClosedLoopAlarmEnd());
+    }
+
+    /**
+     * Stores an operation outcome in the DB.
+     *
+     * @param outcome operation outcome to store
+     * @param targetEntity target entity
+     */
+    protected void storeInDataBase(OperationOutcome2 outcome, String targetEntity) {
+        getDataManager().store(getRequestIdStr(), event.getClosedLoopControlName(), event, targetEntity,
+                        outcome.getClOperation());
+    }
+
+    @Override
+    public ControlLoopResponse makeControlLoopResponse(OperationOutcome outcome) {
+        ControlLoopResponse clRsp = super.makeControlLoopResponse(outcome);
+        clRsp.setTarget("DCAE");
+
+        clRsp.setClosedLoopControlName(event.getClosedLoopControlName());
+        clRsp.setPolicyName(event.getPolicyName());
+        clRsp.setPolicyVersion(event.getPolicyVersion());
+        clRsp.setRequestId(event.getRequestId());
+        clRsp.setVersion(event.getVersion());
+
+        return clRsp;
+    }
+
+    /**
+     * An event onset/abatement.
+     *
+     * @param newEvent the event
+     * @return the status
+     */
+    public NewEventStatus onNewEvent(VirtualControlLoopEvent newEvent) {
+        try {
+            checkEventSyntax(newEvent);
+
+            if (newEvent.getClosedLoopEventStatus() == ControlLoopEventStatus.ONSET) {
+                if (newEvent.equals(event)) {
+                    return NewEventStatus.FIRST_ONSET;
+                }
+
+                bumpOffsets();
+                return NewEventStatus.SUBSEQUENT_ONSET;
+
+            } else {
+                if (abatement == null) {
+                    abatement = newEvent;
+                    bumpAbatements();
+                    return NewEventStatus.FIRST_ABATEMENT;
+                } else {
+                    bumpAbatements();
+                    return NewEventStatus.SUBSEQUENT_ABATEMENT;
+                }
+            }
+        } catch (ControlLoopException e) {
+            logger.error("{}: onNewEvent threw an exception", this, e);
+            return NewEventStatus.SYNTAX_ERROR;
+        }
+    }
+
+    /**
+     * Check an event syntax.
+     *
+     * @param event the event syntax
+     * @throws ControlLoopException if an error occurs
+     */
+    protected void checkEventSyntax(VirtualControlLoopEvent event) throws ControlLoopException {
+        validateStatus(event);
+        if (StringUtils.isBlank(event.getClosedLoopControlName())) {
+            throw new ControlLoopException("No control loop name");
+        }
+        if (event.getRequestId() == null) {
+            throw new ControlLoopException("No request ID");
+        }
+        if (event.getClosedLoopEventStatus() == ControlLoopEventStatus.ABATED) {
+            return;
+        }
+        validateTarget(event);
+    }
+
+    /**
+     * Verifies that the event status is valid.
+     *
+     * @param event event to check
+     * @throws ControlLoopException if the status is invalid
+     */
+    protected void validateStatus(VirtualControlLoopEvent event) throws ControlLoopException {
+        if (event.getClosedLoopEventStatus() != ControlLoopEventStatus.ONSET
+                        && event.getClosedLoopEventStatus() != ControlLoopEventStatus.ABATED) {
+            throw new ControlLoopException("Invalid value in closedLoopEventStatus");
+        }
+    }
+
+    /**
+     * Verifies that the event target is valid.
+     *
+     * @param event event to check
+     * @throws ControlLoopException if the status is invalid
+     */
+    protected void validateTarget(VirtualControlLoopEvent event) throws ControlLoopException {
+        if (StringUtils.isBlank(event.getTarget())) {
+            throw new ControlLoopException("No target field");
+        }
+    }
+}
diff --git a/controlloop/common/eventmanager/src/main/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithOutcome.java b/controlloop/common/eventmanager/src/main/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithOutcome.java
new file mode 100644
index 000000000..a94598ef7
--- /dev/null
+++ b/controlloop/common/eventmanager/src/main/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithOutcome.java
@@ -0,0 +1,229 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2021 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.controlloop.eventmanager;
+
+import java.util.Deque;
+import java.util.LinkedList;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import lombok.Getter;
+import lombok.ToString;
+import org.drools.core.WorkingMemory;
+import org.onap.policy.controlloop.ControlLoopException;
+import org.onap.policy.controlloop.ControlLoopNotificationType;
+import org.onap.policy.controlloop.ControlLoopOperation;
+import org.onap.policy.controlloop.ControlLoopResponse;
+import org.onap.policy.controlloop.VirtualControlLoopNotification;
+import org.onap.policy.controlloop.actorserviceprovider.OperationOutcome;
+import org.onap.policy.controlloop.actorserviceprovider.OperationResult;
+import org.onap.policy.controlloop.drl.legacy.ControlLoopParams;
+import org.onap.policy.drools.domain.models.operational.OperationalTarget;
+
+/**
+ * Manager for a single control loop event, with operation outcomes.
+ */
+public abstract class ClEventManagerWithOutcome<T extends Step> extends ClEventManagerWithSteps<T>
+                implements StepContext {
+
+    private static final long serialVersionUID = -1216568161322872641L;
+
+    /**
+     * Number of attempts, so far, for the current step.
+     */
+    @Getter
+    private int attempts;
+
+    /**
+     * Full history of operations that have been processed by the rules. This includes the
+     * items in {@link #partialHistory}.
+     */
+    @Getter
+    private final transient Deque<OperationOutcome2> fullHistory = new LinkedList<>();
+
+    /**
+     * History of operations that have been processed by the rules for the current policy.
+     * When a step is started, its "start" outcome is added. However, once it completes,
+     * its "start" outcome is removed and the "completed" outcome is added.
+     */
+    @Getter
+    private final transient Deque<OperationOutcome2> partialHistory = new LinkedList<>();
+
+
+    /**
+     * Constructs the object.
+     *
+     * @param params control loop parameters
+     * @param requestId event request ID
+     * @param workMem working memory to update if this changes
+     * @throws ControlLoopException if the event is invalid or if a YAML processor cannot
+     *         be created
+     */
+    public ClEventManagerWithOutcome(ControlLoopParams params, UUID requestId, WorkingMemory workMem)
+                    throws ControlLoopException {
+
+        super(params, requestId, workMem);
+    }
+
+    @Override
+    protected void loadPolicy() throws ControlLoopException {
+        partialHistory.clear();
+        super.loadPolicy();
+    }
+
+    @Override
+    public boolean executeStep() {
+        attempts = 0;
+        return super.executeStep();
+    }
+
+    /**
+     * Increments the number of attempts.
+     */
+    public void bumpAttempts() {
+        ++attempts;
+    }
+
+    /**
+     * Determines if the TOSCA should be aborted due to the given outcome.
+     *
+     * @param outcome outcome to examine
+     * @return {@code true} if the TOSCA should be aborted, {@code false} otherwise
+     */
+    public boolean isAbort(OperationOutcome outcome) {
+        return (outcome.getResult() != OperationResult.SUCCESS);
+    }
+
+    /**
+     * Adds the outcome to the history.
+     *
+     * @param outcome outcome to add
+     */
+    public void addToHistory(OperationOutcome outcome) {
+        OperationOutcome2 last = partialHistory.peekLast();
+
+        if (last != null && last.getOutcome().getEnd() == null
+                        && last.getOutcome().isFor(outcome.getActor(), outcome.getOperation())) {
+            // last item was a "start" - remove it
+            partialHistory.removeLast();
+
+            if (fullHistory.peekLast() == last) {
+                fullHistory.removeLast();
+            }
+        }
+
+        OperationOutcome2 outcome2 = makeOperationOutcome2(outcome);
+        partialHistory.add(outcome2);
+        fullHistory.add(outcome2);
+    }
+
+    /**
+     * Makes a notification message for the current operation.
+     *
+     * @return a new notification
+     */
+    public VirtualControlLoopNotification makeNotification() {
+        VirtualControlLoopNotification notif = new VirtualControlLoopNotification();
+        populateNotification(notif);
+
+        if (getFinalResult() != null) {
+            return notif;
+        }
+
+        OperationOutcome2 last = partialHistory.peekLast();
+        if (last == null) {
+            return notif;
+        }
+
+        notif.setMessage(last.getClOperation().toHistory());
+        notif.setHistory(partialHistory.stream().map(OperationOutcome2::getClOperation).collect(Collectors.toList()));
+
+        return notif;
+    }
+
+    /**
+     * Populates a notification structure.
+     *
+     * @param notif the notification to populate
+     */
+    protected void populateNotification(VirtualControlLoopNotification notif) {
+        notif.setNotification(ControlLoopNotificationType.OPERATION);
+        notif.setFrom("policy");
+        notif.setPolicyVersion(getPolicyVersion());
+    }
+
+    /**
+     * Get the last operation, as a message.
+     *
+     * @return the last operation, as a message
+     */
+    public String getOperationMessage() {
+        OperationOutcome2 last = fullHistory.peekLast();
+        return (last == null ? null : last.getClOperation().toMessage());
+    }
+
+    /**
+     * Makes a control loop response.
+     *
+     * @param outcome operation outcome
+     * @return a new control loop response, or {@code null} if none is required
+     */
+    public ControlLoopResponse makeControlLoopResponse(OperationOutcome outcome) {
+        ControlLoopResponse clRsp = new ControlLoopResponse();
+        clRsp.setFrom(outcome.getActor());
+
+        return clRsp;
+    }
+
+    @Getter
+    @ToString
+    public class OperationOutcome2 {
+        private final int attempt;
+        private final OperationOutcome outcome;
+        private final ControlLoopOperation clOperation;
+
+        /**
+         * Constructs the object.
+         *
+         * @param outcome outcome of the operation
+         */
+        public OperationOutcome2(OperationOutcome outcome) {
+            this.outcome = outcome;
+            this.attempt = attempts;
+
+            clOperation = outcome.toControlLoopOperation();
+
+            // TODO encode()?
+            OperationalTarget target = getPolicy().getActorOperation().getTarget();
+            String targetStr = (target != null ? target.toString() : null);
+            clOperation.setTarget(targetStr);
+
+            if (outcome.getEnd() == null) {
+                clOperation.setOutcome("Started");
+            } else if (clOperation.getOutcome() == null) {
+                clOperation.setOutcome("");
+            }
+        }
+    }
+
+    protected OperationOutcome2 makeOperationOutcome2(OperationOutcome outcome) {
+        return new OperationOutcome2(outcome);
+    }
+}
diff --git a/controlloop/common/eventmanager/src/main/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithSteps.java b/controlloop/common/eventmanager/src/main/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithSteps.java
new file mode 100644
index 000000000..6f6cd0fda
--- /dev/null
+++ b/controlloop/common/eventmanager/src/main/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithSteps.java
@@ -0,0 +1,341 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2021 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.controlloop.eventmanager;
+
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.UUID;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NonNull;
+import lombok.Setter;
+import lombok.ToString;
+import org.drools.core.WorkingMemory;
+import org.kie.api.runtime.rule.FactHandle;
+import org.onap.policy.controlloop.ControlLoopException;
+import org.onap.policy.controlloop.actorserviceprovider.OperationFinalResult;
+import org.onap.policy.controlloop.actorserviceprovider.OperationOutcome;
+import org.onap.policy.controlloop.actorserviceprovider.OperationResult;
+import org.onap.policy.controlloop.actorserviceprovider.TargetType;
+import org.onap.policy.controlloop.actorserviceprovider.parameters.ControlLoopOperationParams;
+import org.onap.policy.controlloop.drl.legacy.ControlLoopParams;
+import org.onap.policy.drools.domain.models.operational.ActorOperation;
+import org.onap.policy.drools.domain.models.operational.Operation;
+import org.onap.policy.drools.domain.models.operational.OperationalTarget;
+import org.onap.policy.drools.system.PolicyEngine;
+import org.onap.policy.drools.system.PolicyEngineConstants;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Manager for a single control loop event. Processing progresses through each policy,
+ * which involves at least one step. As a step is processed, additional preprocessor steps
+ * may be pushed onto the queue (e.g., locks, A&AI queries, guards).
+ */
+@ToString(onlyExplicitlyIncluded = true)
+public abstract class ClEventManagerWithSteps<T extends Step> extends ControlLoopEventManager implements StepContext {
+
+    private static final Logger logger = LoggerFactory.getLogger(ClEventManagerWithSteps.class);
+    private static final long serialVersionUID = -1216568161322872641L;
+
+    /**
+     * Maximum number of steps, for a single policy, allowed in the queue at a time. This
+     * prevents an infinite loop occurring with calls to {@link #loadPreprocessorSteps()}.
+     */
+    public static final int MAX_STEPS = 30;
+
+    public enum State {
+        LOAD_POLICY, POLICY_LOADED, AWAITING_OUTCOME, DONE
+    }
+
+    /**
+     * Request ID, as a String.
+     */
+    @Getter
+    private final String requestIdStr;
+
+    @Getter
+    @Setter
+    private State state;
+
+    /**
+     * {@code True} if the event has been accepted (i.e., an "ACTIVE" notification has
+     * been delivered), {@code false} otherwise.
+     */
+    @Getter
+    @Setter
+    private boolean accepted;
+
+    /**
+     * Queue of steps waiting to be performed.
+     */
+    @Getter
+    private final transient Deque<T> steps = new ArrayDeque<>(6);
+
+    /**
+     * Policy currently being processed.
+     */
+    @Getter(AccessLevel.PROTECTED)
+    private Operation policy;
+
+    /**
+     * Result of the last policy operation. This is just a place where the rules can store
+     * the value for passing to {@link #loadNextPolicy()}.
+     */
+    @Getter
+    @Setter
+    private OperationResult result = OperationResult.SUCCESS;
+
+    @Getter
+    @ToString.Include
+    private int numOnsets = 1;
+    @Getter
+    @ToString.Include
+    private int numAbatements = 0;
+
+    @Getter
+    private OperationFinalResult finalResult = null;
+
+    /**
+     * Message to be placed into the final notification. Typically used when something
+     * causes processing to abort.
+     */
+    @Getter
+    private String finalMessage = null;
+
+    private final transient WorkingMemory workMem;
+    private transient FactHandle factHandle;
+
+
+    /**
+     * Constructs the object.
+     *
+     * @param params control loop parameters
+     * @param requestId event request ID
+     * @param workMem working memory to update if this changes
+     * @throws ControlLoopException if the event is invalid or if a YAML processor cannot
+     *         be created
+     */
+    public ClEventManagerWithSteps(ControlLoopParams params, UUID requestId, WorkingMemory workMem)
+                    throws ControlLoopException {
+
+        super(params, requestId);
+
+        if (requestId == null) {
+            throw new ControlLoopException("No request ID");
+        }
+
+        this.workMem = workMem;
+        this.requestIdStr = getRequestId().toString();
+    }
+
+    @Override
+    public void destroy() {
+        for (T step : getSteps()) {
+            step.cancel();
+        }
+
+        super.destroy();
+    }
+
+    /**
+     * Starts the manager and loads the first policy.
+     *
+     * @throws ControlLoopException if the processor cannot get a policy
+     */
+    public void start() throws ControlLoopException {
+        if (!isActive()) {
+            throw new IllegalStateException("manager is no longer active");
+        }
+
+        if ((factHandle = workMem.getFactHandle(this)) == null) {
+            throw new IllegalStateException("manager is not in working memory");
+        }
+
+        if (!getSteps().isEmpty()) {
+            throw new IllegalStateException("manager already started");
+        }
+
+        loadPolicy();
+    }
+
+    /**
+     * Indicates that processing has been aborted.
+     *
+     * @param finalState final state
+     * @param finalResult final result
+     * @param finalMessage final message
+     */
+    public void abort(@NonNull State finalState, OperationFinalResult finalResult, String finalMessage) {
+        this.state = finalState;
+        this.finalResult = finalResult;
+        this.finalMessage = finalMessage;
+    }
+
+    /**
+     * Loads the next policy.
+     *
+     * @param lastResult result from the last policy
+     *
+     * @throws ControlLoopException if the processor cannot get a policy
+     */
+    public void loadNextPolicy(@NonNull OperationResult lastResult) throws ControlLoopException {
+        getProcessor().nextPolicyForResult(lastResult);
+        loadPolicy();
+    }
+
+    /**
+     * Loads the current policy.
+     *
+     * @throws ControlLoopException if the processor cannot get a policy
+     */
+    protected void loadPolicy() throws ControlLoopException {
+        if ((finalResult = getProcessor().checkIsCurrentPolicyFinal()) != null) {
+            // final policy - nothing more to do
+            return;
+        }
+
+        policy = getProcessor().getCurrentPolicy();
+
+        ActorOperation actor = policy.getActorOperation();
+
+        OperationalTarget target = actor.getTarget();
+        String targetType = (target != null ? target.getTargetType() : null);
+        Map<String, String> entityIds = (target != null ? target.getEntityIds() : null);
+
+        // convert policy payload from Map<String,String> to Map<String,Object>
+        Map<String, Object> payload = new LinkedHashMap<>();
+        if (actor.getPayload() != null) {
+            payload.putAll(actor.getPayload());
+        }
+
+        // @formatter:off
+        ControlLoopOperationParams params = ControlLoopOperationParams.builder()
+                        .actorService(getActorService())
+                        .actor(actor.getActor())
+                        .operation(actor.getOperation())
+                        .requestId(getRequestId())
+                        .executor(getExecutor())
+                        .retry(policy.getRetries())
+                        .timeoutSec(policy.getTimeout())
+                        .targetType(TargetType.toTargetType(targetType))
+                        .targetEntityIds(entityIds)
+                        .payload(payload)
+                        .startCallback(this::onStart)
+                        .completeCallback(this::onComplete)
+                        .build();
+        // @formatter:on
+
+        // load the policy's operation
+        loadPolicyStep(params);
+    }
+
+    /**
+     * Makes the step associated with the given parameters.
+     *
+     * @param params operation's parameters
+     * @return a new step
+     */
+    protected abstract void loadPolicyStep(ControlLoopOperationParams params);
+
+    /**
+     * Loads the preprocessor steps needed by the step that's at the front of the queue.
+     */
+    public void loadPreprocessorSteps() {
+        if (getSteps().size() >= MAX_STEPS) {
+            throw new IllegalStateException("too many steps");
+        }
+
+        // initialize the step so we can query its properties
+        getSteps().peek().init();
+    }
+
+    /**
+     * Executes the first step in the queue.
+     *
+     * @return {@code true} if the step was started, {@code false} if it is no longer
+     *         needed (or if the queue is empty)
+     */
+    public boolean executeStep() {
+        T step = getSteps().peek();
+        if (step == null) {
+            return false;
+        }
+
+        return step.start(getEndTimeMs() - System.currentTimeMillis());
+    }
+
+    /**
+     * Discards the current step, if any.
+     */
+    public void nextStep() {
+        getSteps().poll();
+    }
+
+    /**
+     * Delivers a notification to a topic.
+     *
+     * @param sinkName name of the topic sink
+     * @param notification notification to be published, or {@code null} if nothing is to
+     *        be published
+     * @param notificationType type of notification, used when logging error messages
+     * @param ruleName name of the rule doing the publishing
+     */
+    public <N> void deliver(String sinkName, N notification, String notificationType, String ruleName) {
+        try {
+            if (notification != null) {
+                getPolicyEngineManager().deliver(sinkName, notification);
+            }
+
+        } catch (RuntimeException e) {
+            logger.warn("{}: {}.{}: manager={} exception publishing {}", getClosedLoopControlName(), getPolicyName(),
+                            ruleName, this, notificationType, e);
+        }
+    }
+
+    protected int bumpOffsets() {
+        return numOnsets++;
+    }
+
+    protected int bumpAbatements() {
+        return numAbatements++;
+    }
+
+    @Override
+    public void onStart(OperationOutcome outcome) {
+        super.onStart(outcome);
+        workMem.update(factHandle, this);
+    }
+
+    @Override
+    public void onComplete(OperationOutcome outcome) {
+        super.onComplete(outcome);
+        workMem.update(factHandle, this);
+    }
+
+    // these following methods may be overridden by junit tests
+
+    protected PolicyEngine getPolicyEngineManager() {
+        return PolicyEngineConstants.getManager();
+    }
+}
diff --git a/controlloop/common/eventmanager/src/test/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithEventTest.java b/controlloop/common/eventmanager/src/test/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithEventTest.java
new file mode 100644
index 000000000..1a4c1b5b2
--- /dev/null
+++ b/controlloop/common/eventmanager/src/test/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithEventTest.java
@@ -0,0 +1,380 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2021 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.controlloop.eventmanager;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.UUID;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.atomic.AtomicReference;
+import org.drools.core.WorkingMemory;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.kie.api.runtime.rule.FactHandle;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+import org.onap.policy.common.utils.coder.Coder;
+import org.onap.policy.common.utils.coder.CoderException;
+import org.onap.policy.common.utils.coder.StandardYamlCoder;
+import org.onap.policy.common.utils.resources.ResourceUtils;
+import org.onap.policy.controlloop.ControlLoopEventStatus;
+import org.onap.policy.controlloop.ControlLoopException;
+import org.onap.policy.controlloop.ControlLoopResponse;
+import org.onap.policy.controlloop.ControlLoopTargetType;
+import org.onap.policy.controlloop.VirtualControlLoopEvent;
+import org.onap.policy.controlloop.VirtualControlLoopNotification;
+import org.onap.policy.controlloop.actorserviceprovider.ActorService;
+import org.onap.policy.controlloop.actorserviceprovider.Operation;
+import org.onap.policy.controlloop.actorserviceprovider.OperationOutcome;
+import org.onap.policy.controlloop.actorserviceprovider.OperationResult;
+import org.onap.policy.controlloop.actorserviceprovider.Operator;
+import org.onap.policy.controlloop.actorserviceprovider.parameters.ControlLoopOperationParams;
+import org.onap.policy.controlloop.actorserviceprovider.spi.Actor;
+import org.onap.policy.controlloop.drl.legacy.ControlLoopParams;
+import org.onap.policy.controlloop.eventmanager.ClEventManagerWithEvent.NewEventStatus;
+import org.onap.policy.controlloop.ophistory.OperationHistoryDataManager;
+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.system.PolicyEngine;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicy;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaServiceTemplate;
+
+@RunWith(MockitoJUnitRunner.class)
+public class ClEventManagerWithEventTest {
+    private static final UUID REQ_ID = UUID.randomUUID();
+    private static final String CL_NAME = "my-closed-loop-name";
+    private static final String POLICY_NAME = "my-policy-name";
+    private static final String POLICY_SCOPE = "my-scope";
+    private static final String POLICY_VERSION = "1.2.3";
+    private static final String SIMPLE_ACTOR = "First";
+    private static final String SIMPLE_OPERATION = "OperationA";
+    private static final String TARGET_PROP = "my-target-property";
+    private static final String MY_TARGET = "my-target";
+    private static final String EVENT_MGR_MULTI_YAML =
+                    "../eventmanager/src/test/resources/eventManager/event-mgr-multi.yaml";
+    private static final String EVENT_MGR_SIMPLE_YAML =
+                    "../eventmanager/src/test/resources/eventManager/event-mgr-simple.yaml";
+    private static final Coder yamlCoder = new StandardYamlCoder();
+    private static final String OUTCOME_MSG = "my outcome message";
+
+    @Mock
+    private PolicyEngine engineMgr;
+    @Mock
+    private WorkingMemory workMem;
+    @Mock
+    private FactHandle factHandle;
+    @Mock
+    private Operator policyOperator;
+    @Mock
+    private Operation policyOperation;
+    @Mock
+    private Actor policyActor;
+    @Mock
+    private ActorService actors;
+    @Mock
+    private OperationHistoryDataManager dataMgr;
+    @Mock
+    private ExecutorService executor;
+    @Mock
+    private MyStep stepa;
+    @Mock
+    private MyStep stepb;
+
+    private List<LockImpl> locks;
+    private ToscaPolicy tosca;
+    private ControlLoopParams params;
+    private VirtualControlLoopEvent event;
+    private ClEventManagerWithEvent<MyStep> mgr;
+
+    /**
+     * Sets up.
+     */
+    @Before
+    public void setUp() throws ControlLoopException, CoderException {
+        when(workMem.getFactHandle(any())).thenReturn(factHandle);
+
+        event = new VirtualControlLoopEvent();
+        event.setRequestId(REQ_ID);
+        event.setTarget(TARGET_PROP);
+        event.setAai(new TreeMap<>(Map.of(TARGET_PROP, MY_TARGET)));
+        event.setClosedLoopEventStatus(ControlLoopEventStatus.ONSET);
+        event.setClosedLoopControlName(CL_NAME);
+        event.setTargetType(ControlLoopTargetType.VNF);
+
+        params = new ControlLoopParams();
+        params.setClosedLoopControlName(CL_NAME);
+        params.setPolicyName(POLICY_NAME);
+        params.setPolicyScope(POLICY_SCOPE);
+        params.setPolicyVersion(POLICY_VERSION);
+
+        loadPolicy(EVENT_MGR_SIMPLE_YAML);
+
+        locks = new ArrayList<>();
+
+        mgr = new MyManager(params, event, workMem);
+    }
+
+    @Test
+    public void testConstructor() {
+        assertEquals(POLICY_NAME, mgr.getPolicyName());
+        assertSame(event, mgr.getEvent());
+
+        // valid
+        assertThatCode(() -> mgr.checkEventSyntax(event)).doesNotThrowAnyException();
+
+        // invalid
+        event.setTarget("");
+        assertThatThrownBy(() -> new MyManager(params, event, workMem)).isInstanceOf(ControlLoopException.class);
+    }
+
+    @Test
+    public void testPopulateNotification() throws Exception {
+        loadPolicy(EVENT_MGR_MULTI_YAML);
+        mgr = new MyManager(params, event, workMem);
+
+        // before started
+        assertNotNull(mgr.makeNotification());
+
+        mgr.start();
+
+        mgr.addToHistory(makeCompletedOutcome());
+        mgr.addToHistory(makeCompletedOutcome());
+        mgr.addToHistory(makeCompletedOutcome());
+
+        // check notification while running
+        VirtualControlLoopNotification notif = mgr.makeNotification();
+        assertThat(notif.getMessage()).contains(SIMPLE_ACTOR);
+        assertThat(notif.getHistory()).hasSize(3);
+        assertThat(notif.getAai()).isEqualTo(event.getAai());
+        assertThat(notif.getClosedLoopAlarmEnd()).isEqualTo(event.getClosedLoopAlarmEnd());
+        assertThat(notif.getClosedLoopAlarmStart()).isEqualTo(event.getClosedLoopAlarmStart());
+        assertThat(notif.getClosedLoopControlName()).isEqualTo(event.getClosedLoopControlName());
+        assertThat(notif.getClosedLoopEventClient()).isEqualTo(event.getClosedLoopEventClient());
+        assertThat(notif.getFrom()).isEqualTo("policy");
+        assertThat(notif.getTarget()).isEqualTo(event.getTarget());
+        assertThat(notif.getTargetType()).isEqualTo(event.getTargetType());
+
+        // indicate success and load the next policy - should clear the partial history
+        mgr.loadNextPolicy(OperationResult.SUCCESS);
+
+        // check notification
+        notif = mgr.makeNotification();
+        assertNull(notif.getMessage());
+        assertThat(notif.getHistory()).isEmpty();
+
+        // add outcomes and check again
+        mgr.addToHistory(makeCompletedOutcome());
+        mgr.addToHistory(makeCompletedOutcome());
+
+        notif = mgr.makeNotification();
+        assertNotNull(notif.getMessage());
+
+        // should only have history for last two outcomes
+        assertThat(notif.getHistory()).hasSize(2);
+
+        // indicate failure - should go to final state
+        mgr.loadNextPolicy(OperationResult.FAILURE);
+
+        // check notification
+        notif = mgr.makeNotification();
+        assertNull(notif.getMessage());
+
+        // should be no history
+        assertThat(notif.getHistory()).isEmpty();
+
+        // null case
+        assertThatThrownBy(() -> mgr.loadNextPolicy(null)).isInstanceOf(NullPointerException.class)
+                        .hasMessageContaining("lastResult");
+    }
+
+    @Test
+    public void testStoreInDataBase() throws ControlLoopException {
+        mgr.start();
+        OperationOutcome outcome = makeOutcome();
+        mgr.addToHistory(outcome);
+
+        mgr.storeInDataBase(mgr.getPartialHistory().peekLast(), MY_TARGET);
+
+        verify(dataMgr).store(REQ_ID.toString(), event.getClosedLoopControlName(), event, MY_TARGET,
+                        mgr.getPartialHistory().peekLast().getClOperation());
+    }
+
+    @Test
+    public void testMakeControlLoopResponse() {
+        final OperationOutcome outcome = new OperationOutcome();
+
+        ControlLoopResponse resp = mgr.makeControlLoopResponse(outcome);
+        assertNotNull(resp);
+        assertEquals("DCAE", resp.getTarget());
+        assertEquals(event.getClosedLoopControlName(), resp.getClosedLoopControlName());
+        assertEquals(event.getPolicyName(), resp.getPolicyName());
+        assertEquals(event.getPolicyVersion(), resp.getPolicyVersion());
+        assertEquals(REQ_ID, resp.getRequestId());
+        assertEquals(event.getVersion(), resp.getVersion());
+    }
+
+    @Test
+    public void testOnNewEvent() {
+        VirtualControlLoopEvent event2 = new VirtualControlLoopEvent(event);
+        assertEquals(NewEventStatus.FIRST_ONSET, mgr.onNewEvent(event2));
+
+        event2.setPayload("other payload");
+        assertEquals(NewEventStatus.SUBSEQUENT_ONSET, mgr.onNewEvent(event2));
+        assertEquals(NewEventStatus.SUBSEQUENT_ONSET, mgr.onNewEvent(event2));
+        assertEquals(NewEventStatus.FIRST_ONSET, mgr.onNewEvent(event));
+
+        event2.setClosedLoopEventStatus(ControlLoopEventStatus.ABATED);
+        assertEquals(NewEventStatus.FIRST_ABATEMENT, mgr.onNewEvent(event2));
+
+        assertEquals(NewEventStatus.SUBSEQUENT_ABATEMENT, mgr.onNewEvent(event2));
+        assertEquals(NewEventStatus.SUBSEQUENT_ABATEMENT, mgr.onNewEvent(event2));
+
+        event2.setClosedLoopEventStatus(null);
+        assertEquals(NewEventStatus.SYNTAX_ERROR, mgr.onNewEvent(event2));
+    }
+
+    @Test
+    public void testCheckEventSyntax() {
+        // initially, it's valid
+        assertThatCode(() -> mgr.checkEventSyntax(event)).doesNotThrowAnyException();
+
+        event.setTarget(null);
+        assertThatCode(() -> mgr.checkEventSyntax(event)).isInstanceOf(ControlLoopException.class)
+                        .hasMessage("No target field");
+
+        // abated supersedes previous errors - so it shouldn't throw an exception
+        event.setClosedLoopEventStatus(ControlLoopEventStatus.ABATED);
+        assertThatCode(() -> mgr.checkEventSyntax(event)).doesNotThrowAnyException();
+
+        event.setRequestId(null);
+        assertThatCode(() -> mgr.checkEventSyntax(event)).isInstanceOf(ControlLoopException.class)
+                        .hasMessage("No request ID");
+
+        event.setClosedLoopControlName(null);
+        assertThatCode(() -> mgr.checkEventSyntax(event)).isInstanceOf(ControlLoopException.class)
+                        .hasMessage("No control loop name");
+    }
+
+    @Test
+    public void testValidateStatus() {
+        event.setClosedLoopEventStatus(ControlLoopEventStatus.ONSET);
+        assertThatCode(() -> mgr.checkEventSyntax(event)).doesNotThrowAnyException();
+
+        event.setClosedLoopEventStatus(ControlLoopEventStatus.ABATED);
+        assertThatCode(() -> mgr.checkEventSyntax(event)).doesNotThrowAnyException();
+
+        event.setClosedLoopEventStatus(null);
+        assertThatCode(() -> mgr.checkEventSyntax(event)).isInstanceOf(ControlLoopException.class)
+                        .hasMessage("Invalid value in closedLoopEventStatus");
+    }
+
+    private void loadPolicy(String fileName) throws CoderException {
+        ToscaServiceTemplate template =
+                        yamlCoder.decode(ResourceUtils.getResourceAsString(fileName), ToscaServiceTemplate.class);
+        tosca = template.getToscaTopologyTemplate().getPolicies().get(0).values().iterator().next();
+
+        params.setToscaPolicy(tosca);
+    }
+
+    private OperationOutcome makeCompletedOutcome() {
+        OperationOutcome outcome = makeOutcome();
+        outcome.setEnd(outcome.getStart());
+
+        return outcome;
+    }
+
+    private OperationOutcome makeOutcome() {
+        OperationOutcome outcome = new OperationOutcome();
+        outcome.setActor(SIMPLE_ACTOR);
+        outcome.setOperation(SIMPLE_OPERATION);
+        outcome.setMessage(OUTCOME_MSG);
+        outcome.setResult(OperationResult.SUCCESS);
+        outcome.setStart(Instant.now());
+        outcome.setTarget(MY_TARGET);
+
+        return outcome;
+    }
+
+
+    private class MyManager extends ClEventManagerWithEvent<MyStep> {
+        private static final long serialVersionUID = 1L;
+
+        public MyManager(ControlLoopParams params, VirtualControlLoopEvent event, WorkingMemory workMem)
+                        throws ControlLoopException {
+
+            super(params, event, workMem);
+        }
+
+        @Override
+        protected ExecutorService getBlockingExecutor() {
+            return executor;
+        }
+
+        @Override
+        protected void makeLock(String targetEntity, String requestId, int holdSec, LockCallback callback) {
+            LockImpl lock = new LockImpl(LockState.ACTIVE, targetEntity, requestId, holdSec, callback);
+            locks.add(lock);
+            callback.lockAvailable(lock);
+        }
+
+        @Override
+        public ActorService getActorService() {
+            return actors;
+        }
+
+        @Override
+        public OperationHistoryDataManager getDataManager() {
+            return dataMgr;
+        }
+
+        @Override
+        protected PolicyEngine getPolicyEngineManager() {
+            return engineMgr;
+        }
+
+        @Override
+        protected void loadPolicyStep(ControlLoopOperationParams params) {
+            getSteps().add(new MyStep(this, params, getEvent()));
+        }
+    }
+
+    private static class MyStep extends Step {
+        public MyStep(StepContext stepContext, ControlLoopOperationParams params, VirtualControlLoopEvent event) {
+            super(params, new AtomicReference<>());
+        }
+    }
+}
diff --git a/controlloop/common/eventmanager/src/test/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithOutcomeTest.java b/controlloop/common/eventmanager/src/test/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithOutcomeTest.java
new file mode 100644
index 000000000..d64d2bbc5
--- /dev/null
+++ b/controlloop/common/eventmanager/src/test/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithOutcomeTest.java
@@ -0,0 +1,400 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2021 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.controlloop.eventmanager;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.atomic.AtomicReference;
+import org.drools.core.WorkingMemory;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.kie.api.runtime.rule.FactHandle;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+import org.onap.policy.common.utils.coder.Coder;
+import org.onap.policy.common.utils.coder.CoderException;
+import org.onap.policy.common.utils.coder.StandardYamlCoder;
+import org.onap.policy.common.utils.resources.ResourceUtils;
+import org.onap.policy.controlloop.ControlLoopException;
+import org.onap.policy.controlloop.ControlLoopResponse;
+import org.onap.policy.controlloop.VirtualControlLoopNotification;
+import org.onap.policy.controlloop.actorserviceprovider.ActorService;
+import org.onap.policy.controlloop.actorserviceprovider.Operation;
+import org.onap.policy.controlloop.actorserviceprovider.OperationOutcome;
+import org.onap.policy.controlloop.actorserviceprovider.OperationResult;
+import org.onap.policy.controlloop.actorserviceprovider.Operator;
+import org.onap.policy.controlloop.actorserviceprovider.parameters.ControlLoopOperationParams;
+import org.onap.policy.controlloop.actorserviceprovider.spi.Actor;
+import org.onap.policy.controlloop.drl.legacy.ControlLoopParams;
+import org.onap.policy.controlloop.ophistory.OperationHistoryDataManager;
+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.system.PolicyEngine;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicy;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaServiceTemplate;
+
+@RunWith(MockitoJUnitRunner.class)
+public class ClEventManagerWithOutcomeTest {
+    private static final UUID REQ_ID = UUID.randomUUID();
+    private static final String CL_NAME = "my-closed-loop-name";
+    private static final String POLICY_NAME = "my-policy-name";
+    private static final String POLICY_SCOPE = "my-scope";
+    private static final String POLICY_VERSION = "1.2.3";
+    private static final String SIMPLE_ACTOR = "First";
+    private static final String SIMPLE_OPERATION = "OperationA";
+    private static final String MY_TARGET = "my-target";
+    private static final String EVENT_MGR_MULTI_YAML =
+                    "../eventmanager/src/test/resources/eventManager/event-mgr-multi.yaml";
+    private static final String EVENT_MGR_SIMPLE_YAML =
+                    "../eventmanager/src/test/resources/eventManager/event-mgr-simple.yaml";
+    private static final Coder yamlCoder = new StandardYamlCoder();
+    private static final String OUTCOME_MSG = "my outcome message";
+
+    @Mock
+    private PolicyEngine engineMgr;
+    @Mock
+    private WorkingMemory workMem;
+    @Mock
+    private FactHandle factHandle;
+    @Mock
+    private Operator policyOperator;
+    @Mock
+    private Operation policyOperation;
+    @Mock
+    private Actor policyActor;
+    @Mock
+    private ActorService actors;
+    @Mock
+    private OperationHistoryDataManager dataMgr;
+    @Mock
+    private ExecutorService executor;
+    @Mock
+    private MyStep stepa;
+    @Mock
+    private MyStep stepb;
+
+    private List<LockImpl> locks;
+    private ToscaPolicy tosca;
+    private ControlLoopParams params;
+    private ClEventManagerWithOutcome<MyStep> mgr;
+
+    /**
+     * Sets up.
+     */
+    @Before
+    public void setUp() throws ControlLoopException, CoderException {
+        when(workMem.getFactHandle(any())).thenReturn(factHandle);
+
+        params = new ControlLoopParams();
+        params.setClosedLoopControlName(CL_NAME);
+        params.setPolicyName(POLICY_NAME);
+        params.setPolicyScope(POLICY_SCOPE);
+        params.setPolicyVersion(POLICY_VERSION);
+
+        loadPolicy(EVENT_MGR_SIMPLE_YAML);
+
+        locks = new ArrayList<>();
+
+        mgr = new MyManager(params, REQ_ID, workMem);
+    }
+
+    @Test
+    public void testConstructor() {
+        assertEquals(POLICY_NAME, mgr.getPolicyName());
+
+        // invalid
+        assertThatThrownBy(() -> new MyManager(params, null, workMem)).isInstanceOf(ControlLoopException.class);
+    }
+
+    @Test
+    public void testLoadNextPolicy_testGetFullHistory_testGetPartialHistory() throws Exception {
+        loadPolicy(EVENT_MGR_MULTI_YAML);
+        mgr = new MyManager(params, REQ_ID, workMem);
+
+        // start and load step for first policy
+        mgr.start();
+        assertEquals("OperationA", mgr.getSteps().poll().getOperationName());
+        assertNull(mgr.getFinalResult());
+
+        // add an outcome
+        OperationOutcome outcome = makeOutcome();
+        mgr.addToHistory(outcome);
+
+        // indicate success and load next policy
+        mgr.loadNextPolicy(OperationResult.SUCCESS);
+        assertEquals("OperationB", mgr.getSteps().poll().getOperationName());
+        assertNull(mgr.getFinalResult());
+
+        // loadPolicy() should clear the partial history, but not the full history
+        assertThat(mgr.getPartialHistory()).isEmpty();
+        assertThat(mgr.getFullHistory()).hasSize(1);
+    }
+
+    @Test
+    public void testExecuteStep() {
+        mgr.bumpAttempts();
+
+        // no steps to execute
+        assertFalse(mgr.executeStep());
+        assertEquals(0, mgr.getAttempts());
+    }
+
+    @Test
+    public void testBumpAttempts() {
+        assertEquals(0, mgr.getAttempts());
+
+        mgr.bumpAttempts();
+        mgr.bumpAttempts();
+        assertEquals(2, mgr.getAttempts());
+    }
+
+    @Test
+    public void testIsAbort() {
+        OperationOutcome outcome = makeCompletedOutcome();
+
+        outcome.setResult(OperationResult.FAILURE);
+        assertTrue(mgr.isAbort(outcome));
+
+        // no effect for success
+        outcome.setResult(OperationResult.SUCCESS);
+        assertFalse(mgr.isAbort(outcome));
+    }
+
+    @Test
+    public void testAddToHistory() throws ControlLoopException {
+        mgr.start();
+
+        // add a "start" outcome
+        OperationOutcome outcome = makeOutcome();
+        mgr.addToHistory(outcome);
+
+        assertThat(mgr.getPartialHistory()).hasSize(1);
+        assertThat(mgr.getFullHistory()).hasSize(1);
+
+        // add a "completion" outcome - should replace the start
+        outcome = makeCompletedOutcome();
+        mgr.addToHistory(outcome);
+
+        assertThat(mgr.getPartialHistory()).hasSize(1);
+        assertThat(mgr.getFullHistory()).hasSize(1);
+        assertSame(outcome, mgr.getPartialHistory().peek().getOutcome());
+        assertSame(outcome, mgr.getFullHistory().peek().getOutcome());
+
+        // add another start
+        outcome = makeOutcome();
+        mgr.addToHistory(outcome);
+
+        assertThat(mgr.getPartialHistory()).hasSize(2);
+        assertThat(mgr.getFullHistory()).hasSize(2);
+        assertSame(outcome, mgr.getPartialHistory().peekLast().getOutcome());
+        assertSame(outcome, mgr.getFullHistory().peekLast().getOutcome());
+
+        // remove the last item from the full history and then add a "completion"
+        mgr.getFullHistory().removeLast();
+        outcome = makeCompletedOutcome();
+        mgr.addToHistory(outcome);
+        assertThat(mgr.getPartialHistory()).hasSize(2);
+        assertThat(mgr.getFullHistory()).hasSize(2);
+
+        // add another "start"
+        outcome = makeOutcome();
+        mgr.addToHistory(outcome);
+        assertThat(mgr.getPartialHistory()).hasSize(3);
+        assertThat(mgr.getFullHistory()).hasSize(3);
+
+        // add a "completion" for a different actor - should NOT replace the start
+        outcome = makeCompletedOutcome();
+        outcome.setActor("different-actor");
+        mgr.addToHistory(outcome);
+        assertThat(mgr.getPartialHistory()).hasSize(4);
+        assertThat(mgr.getFullHistory()).hasSize(4);
+        assertSame(outcome, mgr.getPartialHistory().peekLast().getOutcome());
+        assertSame(outcome, mgr.getFullHistory().peekLast().getOutcome());
+    }
+
+    @Test
+    public void testMakeNotification() throws Exception {
+        loadPolicy(EVENT_MGR_MULTI_YAML);
+        mgr = new MyManager(params, REQ_ID, workMem);
+
+        // before started
+        assertNotNull(mgr.makeNotification());
+
+        mgr.start();
+
+        mgr.addToHistory(makeCompletedOutcome());
+        mgr.addToHistory(makeCompletedOutcome());
+        mgr.addToHistory(makeCompletedOutcome());
+
+        // check notification while running
+        VirtualControlLoopNotification notif = mgr.makeNotification();
+        assertThat(notif.getMessage()).contains(SIMPLE_ACTOR);
+        assertThat(notif.getHistory()).hasSize(3);
+
+        // indicate success and load the next policy - should clear the partial history
+        mgr.loadNextPolicy(OperationResult.SUCCESS);
+
+        // check notification
+        notif = mgr.makeNotification();
+        assertNull(notif.getMessage());
+        assertThat(notif.getHistory()).isEmpty();
+
+        // add outcomes and check again
+        mgr.addToHistory(makeCompletedOutcome());
+        mgr.addToHistory(makeCompletedOutcome());
+
+        notif = mgr.makeNotification();
+        assertNotNull(notif.getMessage());
+
+        // should only have history for last two outcomes
+        assertThat(notif.getHistory()).hasSize(2);
+
+        // indicate failure - should go to final state
+        mgr.loadNextPolicy(OperationResult.FAILURE);
+
+        // check notification
+        notif = mgr.makeNotification();
+        assertNull(notif.getMessage());
+
+        // should be no history
+        assertThat(notif.getHistory()).isEmpty();
+
+        // null case
+        assertThatThrownBy(() -> mgr.loadNextPolicy(null)).isInstanceOf(NullPointerException.class)
+                        .hasMessageContaining("lastResult");
+    }
+
+    @Test
+    public void testGetOperationMessage() throws ControlLoopException {
+        // no history yet
+        assertNull(mgr.getOperationMessage());
+
+        // add an outcome
+        mgr.start();
+        OperationOutcome outcome = makeOutcome();
+        mgr.addToHistory(outcome);
+
+        assertThat(mgr.getOperationMessage()).contains("actor=" + SIMPLE_ACTOR)
+                        .contains("operation=" + SIMPLE_OPERATION);
+    }
+
+    @Test
+    public void testMakeControlLoopResponse() {
+        final OperationOutcome outcome = new OperationOutcome();
+        outcome.setActor(SIMPLE_ACTOR);
+
+        ControlLoopResponse resp = mgr.makeControlLoopResponse(outcome);
+        assertNotNull(resp);
+        assertEquals(SIMPLE_ACTOR, resp.getFrom());
+    }
+
+    private void loadPolicy(String fileName) throws CoderException {
+        ToscaServiceTemplate template =
+                        yamlCoder.decode(ResourceUtils.getResourceAsString(fileName), ToscaServiceTemplate.class);
+        tosca = template.getToscaTopologyTemplate().getPolicies().get(0).values().iterator().next();
+
+        params.setToscaPolicy(tosca);
+    }
+
+    private OperationOutcome makeCompletedOutcome() {
+        OperationOutcome outcome = makeOutcome();
+        outcome.setEnd(outcome.getStart());
+
+        return outcome;
+    }
+
+    private OperationOutcome makeOutcome() {
+        OperationOutcome outcome = new OperationOutcome();
+        outcome.setActor(SIMPLE_ACTOR);
+        outcome.setOperation(SIMPLE_OPERATION);
+        outcome.setMessage(OUTCOME_MSG);
+        outcome.setResult(OperationResult.SUCCESS);
+        outcome.setStart(Instant.now());
+        outcome.setTarget(MY_TARGET);
+
+        return outcome;
+    }
+
+
+    private class MyManager extends ClEventManagerWithOutcome<MyStep> {
+        private static final long serialVersionUID = 1L;
+
+        public MyManager(ControlLoopParams params, UUID requestId, WorkingMemory workMem) throws ControlLoopException {
+
+            super(params, requestId, workMem);
+        }
+
+        @Override
+        protected ExecutorService getBlockingExecutor() {
+            return executor;
+        }
+
+        @Override
+        protected void makeLock(String targetEntity, String requestId, int holdSec, LockCallback callback) {
+            LockImpl lock = new LockImpl(LockState.ACTIVE, targetEntity, requestId, holdSec, callback);
+            locks.add(lock);
+            callback.lockAvailable(lock);
+        }
+
+        @Override
+        public ActorService getActorService() {
+            return actors;
+        }
+
+        @Override
+        public OperationHistoryDataManager getDataManager() {
+            return dataMgr;
+        }
+
+        @Override
+        protected PolicyEngine getPolicyEngineManager() {
+            return engineMgr;
+        }
+
+        @Override
+        protected void loadPolicyStep(ControlLoopOperationParams params) {
+            getSteps().add(new MyStep(this, params));
+        }
+    }
+
+
+    private static class MyStep extends Step {
+        public MyStep(StepContext stepContext, ControlLoopOperationParams params) {
+            super(params, new AtomicReference<>());
+        }
+    }
+}
diff --git a/controlloop/common/eventmanager/src/test/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithStepsTest.java b/controlloop/common/eventmanager/src/test/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithStepsTest.java
new file mode 100644
index 000000000..06dc838e2
--- /dev/null
+++ b/controlloop/common/eventmanager/src/test/java/org/onap/policy/controlloop/eventmanager/ClEventManagerWithStepsTest.java
@@ -0,0 +1,482 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2021 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.controlloop.eventmanager;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Deque;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.atomic.AtomicReference;
+import org.drools.core.WorkingMemory;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.kie.api.runtime.rule.FactHandle;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+import org.onap.policy.common.utils.coder.Coder;
+import org.onap.policy.common.utils.coder.CoderException;
+import org.onap.policy.common.utils.coder.StandardYamlCoder;
+import org.onap.policy.common.utils.io.Serializer;
+import org.onap.policy.common.utils.resources.ResourceUtils;
+import org.onap.policy.controlloop.ControlLoopException;
+import org.onap.policy.controlloop.actorserviceprovider.ActorService;
+import org.onap.policy.controlloop.actorserviceprovider.Operation;
+import org.onap.policy.controlloop.actorserviceprovider.OperationFinalResult;
+import org.onap.policy.controlloop.actorserviceprovider.OperationOutcome;
+import org.onap.policy.controlloop.actorserviceprovider.OperationResult;
+import org.onap.policy.controlloop.actorserviceprovider.Operator;
+import org.onap.policy.controlloop.actorserviceprovider.parameters.ControlLoopOperationParams;
+import org.onap.policy.controlloop.actorserviceprovider.spi.Actor;
+import org.onap.policy.controlloop.drl.legacy.ControlLoopParams;
+import org.onap.policy.controlloop.ophistory.OperationHistoryDataManager;
+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.system.PolicyEngine;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicy;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaServiceTemplate;
+
+@RunWith(MockitoJUnitRunner.class)
+public class ClEventManagerWithStepsTest {
+    private static final UUID REQ_ID = UUID.randomUUID();
+    private static final String CL_NAME = "my-closed-loop-name";
+    private static final String POLICY_NAME = "my-policy-name";
+    private static final String POLICY_SCOPE = "my-scope";
+    private static final String POLICY_VERSION = "1.2.3";
+    private static final String SIMPLE_ACTOR = "First";
+    private static final String SIMPLE_OPERATION = "OperationA";
+    private static final String MY_TARGET = "my-target";
+    private static final String EVENT_MGR_MULTI_YAML =
+                    "../eventmanager/src/test/resources/eventManager/event-mgr-multi.yaml";
+    private static final String EVENT_MGR_SIMPLE_YAML =
+                    "../eventmanager/src/test/resources/eventManager/event-mgr-simple.yaml";
+    private static final Coder yamlCoder = new StandardYamlCoder();
+    private static final String OUTCOME_MSG = "my outcome message";
+    private static final String MY_SINK = "my-topic-sink";
+
+    @Mock
+    private PolicyEngine engineMgr;
+    @Mock
+    private WorkingMemory workMem;
+    @Mock
+    private FactHandle factHandle;
+    @Mock
+    private Operator policyOperator;
+    @Mock
+    private Operation policyOperation;
+    @Mock
+    private Actor policyActor;
+    @Mock
+    private ActorService actors;
+    @Mock
+    private OperationHistoryDataManager dataMgr;
+    @Mock
+    private ExecutorService executor;
+    @Mock
+    private MyStep stepa;
+    @Mock
+    private MyStep stepb;
+
+    private List<LockImpl> locks;
+    private ToscaPolicy tosca;
+    private ControlLoopParams params;
+    private ClEventManagerWithSteps<MyStep> mgr;
+
+    /**
+     * Sets up.
+     */
+    @Before
+    public void setUp() throws ControlLoopException, CoderException {
+        when(workMem.getFactHandle(any())).thenReturn(factHandle);
+
+        params = new ControlLoopParams();
+        params.setClosedLoopControlName(CL_NAME);
+        params.setPolicyName(POLICY_NAME);
+        params.setPolicyScope(POLICY_SCOPE);
+        params.setPolicyVersion(POLICY_VERSION);
+
+        loadPolicy(EVENT_MGR_SIMPLE_YAML);
+
+        locks = new ArrayList<>();
+
+        mgr = new MyManager(params, REQ_ID, workMem);
+    }
+
+    @Test
+    public void testConstructor() {
+        assertEquals(POLICY_NAME, mgr.getPolicyName());
+
+        // invalid
+        assertThatThrownBy(() -> new MyManager(params, null, workMem)).isInstanceOf(ControlLoopException.class);
+    }
+
+    @Test
+    public void testDestroy_testGetSteps() {
+        // add some steps to the queue
+        mgr.getSteps().add(stepa);
+        mgr.getSteps().add(stepb);
+
+        mgr.destroy();
+
+        verify(stepa).cancel();
+        verify(stepb).cancel();
+
+        // if superclass destroy() was invoked, then freeLock() should have been submitted
+        // to the executor
+        verify(executor).execute(any());
+    }
+
+    @Test
+    public void testOnStart() throws ControlLoopException {
+        OperationOutcome outcome = makeOutcome();
+
+        mgr.start();
+        mgr.onStart(outcome);
+
+        assertSame(outcome, mgr.getOutcomes().poll());
+        assertThat(mgr.getOutcomes()).isEmpty();
+
+        verify(workMem).update(factHandle, mgr);
+    }
+
+    @Test
+    public void testOnComplete() throws ControlLoopException {
+        OperationOutcome outcome = makeCompletedOutcome();
+
+        mgr.start();
+        mgr.onComplete(outcome);
+
+        assertSame(outcome, mgr.getOutcomes().poll());
+        assertThat(mgr.getOutcomes()).isEmpty();
+
+        verify(workMem).update(factHandle, mgr);
+    }
+
+    @Test
+    public void testToString() {
+        assertNotNull(mgr.toString());
+    }
+
+    @Test
+    public void testStart() throws ControlLoopException {
+        // start it
+        mgr.start();
+
+        // cannot re-start
+        assertThatCode(() -> mgr.start()).isInstanceOf(IllegalStateException.class)
+                        .hasMessage("manager already started");
+    }
+
+    /**
+     * Tests start() when the manager is not in working memory.
+     */
+    @Test
+    public void testStartNotInWorkingMemory() throws ControlLoopException {
+        when(workMem.getFactHandle(any())).thenReturn(null);
+
+        assertThatCode(() -> mgr.start()).isInstanceOf(IllegalStateException.class)
+                        .hasMessage("manager is not in working memory");
+    }
+
+    /**
+     * Tests start() when the manager is not active.
+     */
+    @Test
+    public void testStartInactive() throws Exception {
+        // make an inactive manager by deserializing it
+        RealManager mgr2 = Serializer.roundTrip(new RealManager(params, REQ_ID, workMem));
+        mgr = mgr2;
+
+        // cannot re-start
+        assertThatCode(() -> mgr.start()).isInstanceOf(IllegalStateException.class)
+                        .hasMessage("manager is no longer active");
+    }
+
+    @Test
+    public void testAbort() {
+        mgr.abort(ClEventManagerWithSteps.State.DONE, OperationFinalResult.FINAL_FAILURE_GUARD, "some message");
+
+        assertEquals(ClEventManagerWithSteps.State.DONE, mgr.getState());
+        assertEquals(OperationFinalResult.FINAL_FAILURE_GUARD, mgr.getFinalResult());
+        assertEquals("some message", mgr.getFinalMessage());
+
+        // try null state
+        assertThatThrownBy(() -> mgr.abort(null, OperationFinalResult.FINAL_FAILURE_GUARD, ""))
+                        .isInstanceOf(NullPointerException.class).hasMessageContaining("finalState");
+    }
+
+    @Test
+    public void testLoadNextPolicy() throws Exception {
+        loadPolicy(EVENT_MGR_MULTI_YAML);
+        mgr = new MyManager(params, REQ_ID, workMem);
+
+        // start and load step for first policy
+        mgr.start();
+        assertEquals("OperationA", mgr.getSteps().poll().getOperationName());
+        assertNull(mgr.getFinalResult());
+
+        // indicate success and load next policy
+        mgr.loadNextPolicy(OperationResult.SUCCESS);
+        assertEquals("OperationB", mgr.getSteps().poll().getOperationName());
+        assertNull(mgr.getFinalResult());
+
+        // indicate failure - should go to final failure
+        mgr.loadNextPolicy(OperationResult.FAILURE);
+        assertEquals(OperationFinalResult.FINAL_FAILURE, mgr.getFinalResult());
+    }
+
+    @Test
+    public void testLoadPolicy() throws ControlLoopException {
+        // start() will invoke loadPolicy()
+        mgr.start();
+
+        assertNull(mgr.getFinalResult());
+
+        MyStep step = mgr.getSteps().peek();
+        assertNotNull(step);
+        assertEquals("First", step.getActorName());
+        assertEquals("OperationA", step.getOperationName());
+
+        ControlLoopOperationParams params2 = step.getParams();
+        assertSame(actors, params2.getActorService());
+        assertSame(REQ_ID, params2.getRequestId());
+        assertSame(ForkJoinPool.commonPool(), params2.getExecutor());
+        assertNotNull(params2.getTargetType());
+        assertNotNull(params2.getTargetEntityIds());
+        assertEquals(Integer.valueOf(300), params2.getTimeoutSec());
+        assertEquals(Integer.valueOf(0), params2.getRetry());
+        assertThat(params2.getPayload()).isEmpty();
+        assertNotNull(params2.getStartCallback());
+        assertNotNull(params2.getCompleteCallback());
+    }
+
+    @Test
+    public void testLoadPreprocessorSteps() {
+        stepa = new MyStep(mgr, ControlLoopOperationParams.builder().build()) {
+            @Override
+            protected Operation buildOperation() {
+                return policyOperation;
+            }
+        };
+
+        Deque<MyStep> steps = mgr.getSteps();
+        steps.add(stepa);
+        steps.add(stepb);
+
+        mgr.loadPreprocessorSteps();
+
+        // no additional steps should have been loaded
+        assertThat(steps).hasSize(2);
+
+        assertSame(stepa, steps.poll());
+        assertSame(stepb, steps.poll());
+        assertThat(steps).isEmpty();
+
+        assertNotNull(stepa.getOperation());
+        assertNull(stepb.getOperation());
+    }
+
+    /**
+     * Tests loadPreprocessorSteps() when there are too many steps in the queue.
+     */
+    @Test
+    public void testLoadPreprocessorStepsTooManySteps() {
+        stepa = new MyStep(mgr, ControlLoopOperationParams.builder().build()) {
+            @Override
+            protected Operation buildOperation() {
+                return policyOperation;
+            }
+        };
+
+        Deque<MyStep> steps = mgr.getSteps();
+
+        // load up a bunch of steps
+        for (int nsteps = 0; nsteps < ClEventManagerWithSteps.MAX_STEPS; ++nsteps) {
+            steps.add(stepa);
+        }
+
+        // should fail
+        assertThatIllegalStateException().isThrownBy(() -> mgr.loadPreprocessorSteps()).withMessage("too many steps");
+
+        // add another step, should still fail
+        steps.add(stepa);
+        assertThatIllegalStateException().isThrownBy(() -> mgr.loadPreprocessorSteps()).withMessage("too many steps");
+
+        // remove two steps - should now succeed
+        steps.remove();
+        steps.remove();
+
+        int nsteps = steps.size();
+
+        mgr.loadPreprocessorSteps();
+        assertEquals(nsteps, steps.size());
+    }
+
+    @Test
+    public void testExecuteStep() {
+        // no steps to execute
+        assertFalse(mgr.executeStep());
+
+        // add a step to the queue
+        mgr.getSteps().add(stepa);
+
+        // step returns false
+        when(stepa.start(anyLong())).thenReturn(false);
+        assertFalse(mgr.executeStep());
+
+        // step returns true
+        when(stepa.start(anyLong())).thenReturn(true);
+        assertTrue(mgr.executeStep());
+    }
+
+    @Test
+    public void testNextStep() {
+        mgr.getSteps().add(stepa);
+
+        mgr.nextStep();
+
+        assertThat(mgr.getSteps()).isEmpty();
+    }
+
+    @Test
+    public void testDeliver() {
+        mgr.deliver(MY_SINK, null, "null notification", "null rule");
+        verify(engineMgr, never()).deliver(any(), any());
+
+        mgr.deliver(MY_SINK, "publishA", "A notification", "A rule");
+        verify(engineMgr).deliver(MY_SINK, "publishA");
+
+        // cause deliver() to throw an exception
+        when(engineMgr.deliver(any(), any())).thenThrow(new IllegalStateException("expected exception"));
+        assertThatCode(() -> mgr.deliver(MY_SINK, "publishB", "B notification", "B rule")).doesNotThrowAnyException();
+    }
+
+    private void loadPolicy(String fileName) throws CoderException {
+        ToscaServiceTemplate template =
+                        yamlCoder.decode(ResourceUtils.getResourceAsString(fileName), ToscaServiceTemplate.class);
+        tosca = template.getToscaTopologyTemplate().getPolicies().get(0).values().iterator().next();
+
+        params.setToscaPolicy(tosca);
+    }
+
+    private OperationOutcome makeCompletedOutcome() {
+        OperationOutcome outcome = makeOutcome();
+        outcome.setEnd(outcome.getStart());
+
+        return outcome;
+    }
+
+    private OperationOutcome makeOutcome() {
+        OperationOutcome outcome = new OperationOutcome();
+        outcome.setActor(SIMPLE_ACTOR);
+        outcome.setOperation(SIMPLE_OPERATION);
+        outcome.setMessage(OUTCOME_MSG);
+        outcome.setResult(OperationResult.SUCCESS);
+        outcome.setStart(Instant.now());
+        outcome.setTarget(MY_TARGET);
+
+        return outcome;
+    }
+
+
+    private class MyManager extends ClEventManagerWithSteps<MyStep> {
+        private static final long serialVersionUID = 1L;
+
+        public MyManager(ControlLoopParams params, UUID requestId, WorkingMemory workMem) throws ControlLoopException {
+
+            super(params, requestId, workMem);
+        }
+
+        @Override
+        protected ExecutorService getBlockingExecutor() {
+            return executor;
+        }
+
+        @Override
+        protected void makeLock(String targetEntity, String requestId, int holdSec, LockCallback callback) {
+            LockImpl lock = new LockImpl(LockState.ACTIVE, targetEntity, requestId, holdSec, callback);
+            locks.add(lock);
+            callback.lockAvailable(lock);
+        }
+
+        @Override
+        public ActorService getActorService() {
+            return actors;
+        }
+
+        @Override
+        public OperationHistoryDataManager getDataManager() {
+            return dataMgr;
+        }
+
+        @Override
+        protected PolicyEngine getPolicyEngineManager() {
+            return engineMgr;
+        }
+
+        @Override
+        protected void loadPolicyStep(ControlLoopOperationParams params) {
+            getSteps().add(new MyStep(this, params));
+        }
+    }
+
+
+    private static class RealManager extends ClEventManagerWithSteps<MyStep> {
+        private static final long serialVersionUID = 1L;
+
+        public RealManager(ControlLoopParams params, UUID requestId, WorkingMemory workMem)
+                        throws ControlLoopException {
+
+            super(params, requestId, workMem);
+        }
+
+        @Override
+        protected void loadPolicyStep(ControlLoopOperationParams params) {
+            getSteps().add(new MyStep(this, params));
+        }
+    }
+
+    private static class MyStep extends Step {
+        public MyStep(StepContext stepContext, ControlLoopOperationParams params) {
+            super(params, new AtomicReference<>());
+        }
+    }
+}