domain/pools/Monitor.java

	Monitor.java revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 *ident "%Z%%M% %I% %E% SMI"
 */

package com.sun.solaris.domain.pools;

import java.util.Map;

import com.sun.solaris.service.pools.Configuration;
import com.sun.solaris.service.pools.Resource;
import com.sun.solaris.service.pools.PoolsException;

/**
 * A monitoring class. The user of this interface can retrieve
 * monitoring information related to the configuration which is
 * examined.
 */

public interface Monitor {
    /**
     * Initialize the monitoring object using details from the
     * supplied configuration.
     *
     * @param conf The configuration to be monitored.
     * @throws PoolsException If the initialize fails.
     * @throws StaleMonitorException If the resource monitors
     * cannot be accessed.
     */
    public void initialize(Configuration conf) throws PoolsException,
        StaleMonitorException;

    /**
     * Return the next sample.
     *
     * This call is a blocking call. The sample will only be
     * returned after pausing the invoking thread for the "sample
     * interval".
     *
     * @throws StaleMonitorException If the sample fails.
     * @throws PoolsException If there is an error manipulating the
     * pools configuration.
     * @throws InterruptedException If the thread is interrupted
     * while waiting for the sampling time to arrive.  The caller
     * may wish to check other conditions before possibly
     * reinitiating the sample.
     */
    public void getNext() throws StaleMonitorException, PoolsException,
        InterruptedException;

    /**
     * Return the number of samples taken.  This is the number of
     * successful calls to <code>getNext()</code>.
     */
    public int getSampleCount();

    /**
     * Return the utilization for supplied resource.
     *
     * @param res The resource to be examined.
     *
     * @throws StaleMonitorException if the resource cannot be accessed.
     */
    public double getUtilization(Resource res) throws StaleMonitorException;
    public boolean isValid();
    public ResourceMonitor get(Resource res) throws StaleMonitorException;
}

/**
 * Indicates that a monitor must be re-initialized. This can occur
 * for a number of reasons, including:
 *
 * <ul>
 * <li><p>
 * Resources created, modified, destroyed whilst sampling
 * </ul>
 */
class StaleMonitorException extends Exception {
}