archive/plugins/org.eclipse.app4mc.multicore.execution.logic.btf/src/org/eclipse/app4mc/multicore/execution/logic/btf/fsm/BtfTaskFSM.java

/*******************************************************************************
 * Copyright (c) 2017, 2018 Dortmund University of Applied Sciences and Arts and others.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *   Dortmund University of Applied Sciences and Arts - initial API and implementation
 *******************************************************************************/

package org.eclipse.app4mc.multicore.execution.logic.btf.fsm;

public class BtfTaskFSM {

	private static final BtfTaskState[][] multi = new BtfTaskState[BtfTaskState.COUNT][BtfTaskEvent.COUNT];

	static {
		// every non transition is null
		/* outgoing transitions for state POLLING */
		makeTransition(BtfTaskState.POLLING, BtfTaskEvent.RUN, BtfTaskState.RUNNING);
		makeTransition(BtfTaskState.POLLING, BtfTaskEvent.PARK, BtfTaskState.PARKING);
		/* outgoing transitions for state RUNNING */
		makeTransition(BtfTaskState.RUNNING, BtfTaskEvent.TERMINATE, BtfTaskState.TERMINATED);
		makeTransition(BtfTaskState.RUNNING, BtfTaskEvent.PREEMPT, BtfTaskState.READY);
		makeTransition(BtfTaskState.RUNNING, BtfTaskEvent.POLL, BtfTaskState.POLLING);
		makeTransition(BtfTaskState.RUNNING, BtfTaskEvent.WAIT, BtfTaskState.WAITING);
		/* outgoing transitions for state TERMINATED */
		// none
		/* outgoing transitions for state NOT_INITIALIZED */
		makeTransition(BtfTaskState.NOT_INITIALIZED, BtfTaskEvent.ACTIVATE, BtfTaskState.ACTIVE);
		/* outgoing transitions for state ACTIVE */
		makeTransition(BtfTaskState.ACTIVE, BtfTaskEvent.START, BtfTaskState.RUNNING);
		/* outgoing transitions for state READY */
		makeTransition(BtfTaskState.READY, BtfTaskEvent.RESUME, BtfTaskState.RUNNING);
		/* outgoing transitions for state PARKING */
		makeTransition(BtfTaskState.PARKING, BtfTaskEvent.RELEASE_PARKING, BtfTaskState.READY);
		makeTransition(BtfTaskState.PARKING, BtfTaskEvent.POLL_PARKING, BtfTaskState.POLLING);
		/* outgoing transitions for state WAITING */
		makeTransition(BtfTaskState.WAITING, BtfTaskEvent.RELEASE, BtfTaskState.READY);
	}

	private static void makeTransition(final BtfTaskState oldState, final BtfTaskEvent e, final BtfTaskState newState) {
		multi[oldState.val()][e.val()] = newState;
	}

	private BtfTaskState currentState;

	public BtfTaskFSM(final BtfTaskState start) {
		this.currentState = start;
	}

	public void setState(final BtfTaskState state) {
		this.currentState = state;
	}

	public BtfTaskState getState() {
		return this.currentState;
	}

	public boolean dispatchEvent(final BtfTaskEvent event) {
		final BtfTaskState newState = multi[this.currentState.val()][event.val()];
		if (newState != null) {
			this.currentState = newState;
			return true;
		}
		// no state change
		return false;
	}

}