# AbstractRuntime.java

    /*******************************************************************************
     * Copyright (c) 2009, 2013 Mountainminds GmbH & Co. KG and Contributors
     * All rights reserved. This program and the accompanying materials
     * are made available under the terms of the Eclipse Public License v1.0
     * which accompanies this distribution, and is available at
     * http://www.eclipse.org/legal/epl-v10.html
     *
     * Contributors:
     *    Marc R. Hoffmann - initial API and implementation
     *
     *******************************************************************************/
    package org.jacoco.core.runtime;

    import java.lang.reflect.Field;
    import java.util.Random;

    import org.jacoco.core.internal.instr.InstrSupport;

    /**
     * Base {@link IRuntime} implementation.
     */
    public abstract class AbstractRuntime implements IRuntime {

    	/** access to the runtime data */
    	protected RuntimeData data;

    	public void disconnect(final Class<?> type) throws Exception {
    		if (!type.isInterface()) {
    			final Field dataField = type
    					.getDeclaredField(InstrSupport.DATAFIELD_NAME);
    			dataField.setAccessible(true);
    			dataField.set(null, null);
    		}
    	}

    	/**
    	 * Subclasses must call this method when overwriting it.
    	 */
    	public void startup(final RuntimeData data) throws Exception {
    		this.data = data;
    	}

    	private static final Random RANDOM = new Random();

    	/**
    	 * Creates a random session identifier.
    	 *
    	 * @return random session identifier
    	 */
    	public static String createRandomId() {
    		return Integer.toHexString(RANDOM.nextInt());
    	}

    }