| Clover coverage report - Ledge Components - SNAPSHOT |
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| Source file | Conditionals | Statements | Methods | TOTAL | |||||||||||||||
| ConcurrencyControlValve.java | 0% | 0% | 0% | 0% |
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| 1 | // | |
| 2 | // Copyright (c) 2003-2005, Caltha - Gajda, Krzewski, Mach, Potempski Sp.J. | |
| 3 | // All rights reserved. | |
| 4 | // | |
| 5 | // Redistribution and use in source and binary forms, with or without modification, | |
| 6 | // are permitted provided that the following conditions are met: | |
| 7 | // | |
| 8 | // * Redistributions of source code must retain the above copyright notice, | |
| 9 | // this list of conditions and the following disclaimer. | |
| 10 | // * Redistributions in binary form must reproduce the above copyright notice, | |
| 11 | // this list of conditions and the following disclaimer in the documentation | |
| 12 | // and/or other materials provided with the distribution. | |
| 13 | // * Neither the name of the Caltha - Gajda, Krzewski, Mach, Potempski Sp.J. | |
| 14 | // nor the names of its contributors may be used to endorse or promote products | |
| 15 | // derived from this software without specific prior written permission. | |
| 16 | // | |
| 17 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
| 18 | // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
| 19 | // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
| 20 | // IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, | |
| 21 | // INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, | |
| 22 | // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, | |
| 23 | // OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, | |
| 24 | // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| 25 | // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| 26 | // POSSIBILITY OF SUCH DAMAGE. | |
| 27 | // | |
| 28 | package org.objectledge.pipeline; | |
| 29 | ||
| 30 | import java.util.concurrent.Semaphore; | |
| 31 | ||
| 32 | import org.jcontainer.dna.Configuration; | |
| 33 | import org.jcontainer.dna.ConfigurationException; | |
| 34 | import org.objectledge.context.Context; | |
| 35 | import org.objectledge.statistics.DataSource; | |
| 36 | import org.objectledge.statistics.Graph; | |
| 37 | import org.objectledge.statistics.ReflectiveStatisticsProvider; | |
| 38 | ||
| 39 | /** | |
| 40 | * A valve that provides control over the number of threads executing another valve. | |
| 41 | * | |
| 42 | * @author <a href="mailto:rafal@caltha.pl">Rafal Krzewski</a> | |
| 43 | * @version $Id: ConcurrencyControlValve.java,v 1.8 2005/08/04 11:54:09 rafal Exp $ | |
| 44 | */ | |
| 45 | public class ConcurrencyControlValve | |
| 46 | extends ReflectiveStatisticsProvider | |
| 47 | implements Valve | |
| 48 | { | |
| 49 | private final Valve nestedValve; | |
| 50 | ||
| 51 | private final Semaphore semaphore; | |
| 52 | ||
| 53 | private final int limit; | |
| 54 | ||
| 55 | private volatile int threadCount = 0; | |
| 56 | ||
| 57 | /** | |
| 58 | * Creates new ConcurrencyControlValve instance. | |
| 59 | * | |
| 60 | * @param nestedValve the valve to control. | |
| 61 | * @param limit the maximum number of threads allowed to execute, or 0 for unlimited. | |
| 62 | */ | |
| 63 | 0 | public ConcurrencyControlValve(final Valve nestedValve, final int limit) |
| 64 | { | |
| 65 | 0 | this.nestedValve = nestedValve; |
| 66 | 0 | this.limit = limit; |
| 67 | 0 | if(limit > 0) |
| 68 | { | |
| 69 | 0 | semaphore = new Semaphore(limit, true); |
| 70 | } | |
| 71 | else | |
| 72 | { | |
| 73 | 0 | semaphore = null; |
| 74 | } | |
| 75 | } | |
| 76 | ||
| 77 | /** | |
| 78 | * Creates a new ConcurrencyControlValve instance. | |
| 79 | * | |
| 80 | * @param nestedValve the valve to control. | |
| 81 | * @param config the confguration object. | |
| 82 | * @throws ConfigurationException if the configuration is incorrect. | |
| 83 | */ | |
| 84 | 0 | public ConcurrencyControlValve(final Valve nestedValve, final Configuration config) |
| 85 | throws ConfigurationException | |
| 86 | { | |
| 87 | 0 | this(nestedValve, config.getChild("limit").getValueAsInteger()); |
| 88 | } | |
| 89 | ||
| 90 | /** | |
| 91 | * {@inheritDoc} | |
| 92 | */ | |
| 93 | 0 | public void process(Context context) |
| 94 | throws ProcessingException | |
| 95 | { | |
| 96 | 0 | if(semaphore != null) |
| 97 | { | |
| 98 | 0 | try |
| 99 | { | |
| 100 | 0 | semaphore.acquireUninterruptibly(); |
| 101 | 0 | nestedValve.process(context); |
| 102 | } | |
| 103 | finally | |
| 104 | { | |
| 105 | 0 | semaphore.release(); |
| 106 | } | |
| 107 | } | |
| 108 | else | |
| 109 | { | |
| 110 | 0 | try |
| 111 | { | |
| 112 | 0 | threadCount++; |
| 113 | 0 | nestedValve.process(context); |
| 114 | } | |
| 115 | finally | |
| 116 | { | |
| 117 | 0 | threadCount--; |
| 118 | } | |
| 119 | } | |
| 120 | } | |
| 121 | ||
| 122 | // statistics /////////////////////////////////////////////////////////////////////////////// | |
| 123 | ||
| 124 | /** | |
| 125 | * {@inheritDoc} | |
| 126 | */ | |
| 127 | 0 | public String getName() |
| 128 | { | |
| 129 | 0 | return "Concurrency control"; |
| 130 | } | |
| 131 | ||
| 132 | private static final DataSource[] DATA_SOURCES = { | |
| 133 | new DataSource("concurrency_threads_running", "Running threads", | |
| 134 | DataSource.Type.GAUGE, DataSource.Graph.LINE1), | |
| 135 | new DataSource("concurrency_threads_waiting", "Waiting threads", | |
| 136 | DataSource.Type.GAUGE, DataSource.Graph.LINE1) }; | |
| 137 | ||
| 138 | private static final Graph[] GRAPHS = { new Graph("concurrency", "Execution concurrency", null, | |
| 139 | DATA_SOURCES, "threads") }; | |
| 140 | ||
| 141 | /** | |
| 142 | * {@inheritDoc} | |
| 143 | */ | |
| 144 | 0 | public Graph[] getGraphs() |
| 145 | { | |
| 146 | 0 | return GRAPHS; |
| 147 | } | |
| 148 | ||
| 149 | /** | |
| 150 | * {@inheritDoc} | |
| 151 | */ | |
| 152 | 0 | public DataSource[] getDataSources() |
| 153 | { | |
| 154 | 0 | return DATA_SOURCES; |
| 155 | } | |
| 156 | ||
| 157 | /** | |
| 158 | * Returns the number of concurrently executing threads. | |
| 159 | * | |
| 160 | * @return the number of concurrently executing threads. | |
| 161 | */ | |
| 162 | 0 | public Number getConcurrencyThreadsRunning() |
| 163 | { | |
| 164 | 0 | if(semaphore != null) |
| 165 | { | |
| 166 | 0 | return new Integer(limit - semaphore.availablePermits()); |
| 167 | } | |
| 168 | else | |
| 169 | { | |
| 170 | 0 | return threadCount; |
| 171 | } | |
| 172 | } | |
| 173 | ||
| 174 | /** | |
| 175 | * Returns the number of threads waiting for execution. | |
| 176 | * | |
| 177 | * @return the number of threads waiting for execution. | |
| 178 | */ | |
| 179 | 0 | public Number getConcurrencyThreadsWaiting() |
| 180 | { | |
| 181 | 0 | if(semaphore != null) |
| 182 | { | |
| 183 | 0 | return new Integer(semaphore.getQueueLength()); |
| 184 | } | |
| 185 | else | |
| 186 | { | |
| 187 | 0 | return 0; |
| 188 | } | |
| 189 | } | |
| 190 | } |
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