StatisticMonitoredAttribute.java revision 672:2bb058ce572e 
1/*
2 * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
25package com.sun.corba.se.spi.monitoring;
26
27import java.util.*;
28
29/**
30 * @author Hemanth Puttaswamy
31 *
32 * StatisticsMonitoredAttribute is provided as a convenience to collect the
33 * Statistics of any entity. The getValue() call will be delegated to the
34 * StatisticsAccumulator set by the user.
35 */
36public class StatisticMonitoredAttribute extends MonitoredAttributeBase {
37
38
39    // Every StatisticMonitoredAttribute will have a StatisticAccumulator. User
40    // will use Statisticsaccumulator to accumulate the samples associated with
41    // this Monitored Attribute
42    private StatisticsAccumulator statisticsAccumulator;
43
44    // Mutex is passed from the user class which is providing the sample values.
45    // getValue() and clearState() is synchronized on this user provided mutex
46    private Object  mutex;
47
48
49  ///////////////////////////////////////
50  // operations
51
52
53/**
54 * Constructs the StaisticMonitoredAttribute, builds the required
55 * MonitoredAttributeInfo with Long as the class type and is always
56 * readonly attribute.
57 *
58 * @param name Of this attribute
59 * @param desc should provide a good description on the kind of statistics
60 * collected, a good example is "Connection Response Time Stats will Provide the
61 * detailed stats based on the samples provided from every request completion
62 * time"
63 * @param s is the StatisticsAcumulator that user will use to accumulate the
64 * samples and this Attribute Object will get the computed statistics values
65 * from.
66 * @param mutex using which clearState() and getValue() calls need to be locked.
67 */
68    public  StatisticMonitoredAttribute(String name, String desc,
69        StatisticsAccumulator s, Object mutex)
70    {
71        super( name );
72        MonitoredAttributeInfoFactory f =
73            MonitoringFactories.getMonitoredAttributeInfoFactory();
74        MonitoredAttributeInfo maInfo = f.createMonitoredAttributeInfo(
75                desc, String.class, false, true );
76
77        this.setMonitoredAttributeInfo( maInfo );
78        this.statisticsAccumulator = s;
79        this.mutex = mutex;
80    } // end StatisticMonitoredAttribute
81
82
83
84/**
85 *  Gets the value from the StatisticsAccumulator, the value will be a formatted
86 *  String with the computed statistics based on the samples accumulated in the
87 *  Statistics Accumulator.
88 */
89    public Object getValue( ) {
90        synchronized( mutex ) {
91            return statisticsAccumulator.getValue( );
92        }
93    }
94
95/**
96 *  Clears the state on Statistics Accumulator, After this call all samples are
97 *  treated fresh and the old sample computations are disregarded.
98 */
99    public void clearState( ) {
100        synchronized( mutex ) {
101            statisticsAccumulator.clearState( );
102        }
103    }
104
105/**
106 *  Gets the statistics accumulator associated with StatisticMonitoredAttribute.
107 *  Usually, the user don't need to use this method as they can keep the handle
108 *  to Accumulator to collect the samples.
109 */
110    public StatisticsAccumulator getStatisticsAccumulator( ) {
111        return statisticsAccumulator;
112    }
113} // end StatisticMonitoredAttribute
114