StatisticMonitoredAttribute.java revision 608:7e06bf1dcb09 
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 * <p>
31 *
32 * @author Hemanth Puttaswamy
33 * </p>
34 * <p>
35 * StatisticsMonitoredAttribute is provided as a convenience to collect the
36 * Statistics of any entity. The getValue() call will be delegated to the
37 * StatisticsAccumulator set by the user.
38 * </p>
39 */
40public class StatisticMonitoredAttribute extends MonitoredAttributeBase {
41
42
43    // Every StatisticMonitoredAttribute will have a StatisticAccumulator. User
44    // will use Statisticsaccumulator to accumulate the samples associated with
45    // this Monitored Attribute
46    private StatisticsAccumulator statisticsAccumulator;
47
48    // Mutex is passed from the user class which is providing the sample values.
49    // getValue() and clearState() is synchronized on this user provided mutex
50    private Object  mutex;
51
52
53  ///////////////////////////////////////
54  // operations
55
56
57/**
58 * <p>
59 * Constructs the StaisticMonitoredAttribute, builds the required
60 * MonitoredAttributeInfo with Long as the class type and is always
61 * readonly attribute.
62 * </p>
63 * <p>
64 *
65 * @param name Of this attribute
66 * </p>
67 * <p>
68 * @return a StatisticMonitoredAttribute
69 * </p>
70 * <p>
71 * @param desc should provide a good description on the kind of statistics
72 * collected, a good example is "Connection Response Time Stats will Provide the
73 * detailed stats based on the samples provided from every request completion
74 * time"
75 * </p>
76 * <p>
77 * @param s is the StatisticsAcumulator that user will use to accumulate the
78 * samples and this Attribute Object will get the computed statistics values
79 * from.
80 * </p>
81 * <p>
82 * @param mutex using which clearState() and getValue() calls need to be locked.
83 * </p>
84 */
85    public  StatisticMonitoredAttribute(String name, String desc,
86        StatisticsAccumulator s, Object mutex)
87    {
88        super( name );
89        MonitoredAttributeInfoFactory f =
90            MonitoringFactories.getMonitoredAttributeInfoFactory();
91        MonitoredAttributeInfo maInfo = f.createMonitoredAttributeInfo(
92                desc, String.class, false, true );
93
94        this.setMonitoredAttributeInfo( maInfo );
95        this.statisticsAccumulator = s;
96        this.mutex = mutex;
97    } // end StatisticMonitoredAttribute
98
99
100
101/**
102 *  Gets the value from the StatisticsAccumulator, the value will be a formatted
103 *  String with the computed statistics based on the samples accumulated in the
104 *  Statistics Accumulator.
105 */
106    public Object getValue( ) {
107        synchronized( mutex ) {
108            return statisticsAccumulator.getValue( );
109        }
110    }
111
112/**
113 *  Clears the state on Statistics Accumulator, After this call all samples are
114 *  treated fresh and the old sample computations are disregarded.
115 */
116    public void clearState( ) {
117        synchronized( mutex ) {
118            statisticsAccumulator.clearState( );
119        }
120    }
121
122/**
123 *  Gets the statistics accumulator associated with StatisticMonitoredAttribute.
124 *  Usually, the user don't need to use this method as they can keep the handle
125 *  to Accumulator to collect the samples.
126 */
127    public StatisticsAccumulator getStatisticsAccumulator( ) {
128        return statisticsAccumulator;
129    }
130} // end StatisticMonitoredAttribute
131