001    /*
002     *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003     *
004     *  This file is licensed to You under the Eclipse Public License (EPL);
005     *  You may not use this file except in compliance with the License. You
006     *  may obtain a copy of the License at
007     *
008     *      http://www.opensource.org/licenses/eclipse-1.0.php
009     *
010     *  See the COPYRIGHT.txt file distributed with this work for information
011     *  regarding copyright ownership.
012     */
013    package org.mmtk.utility.options;
014    
015    import static org.mmtk.policy.immix.ImmixConstants.DEFAULT_DEFRAG_HEADROOM_FRACTION;
016    
017    public class DefragHeadroomFraction extends org.vmutil.options.FloatOption {
018      /**
019       * Create the option.
020       */
021      public DefragHeadroomFraction() {
022        super(Options.set, "Defrag Headroom Fraction",
023              "Allow the defrag this fraction of the heap as headroom during defrag.",
024              DEFAULT_DEFRAG_HEADROOM_FRACTION);
025      }
026    
027      /**
028       * Ensure the value is valid.
029       */
030      @Override
031      protected void validate() {
032        failIf((this.value < 0 || this.value > 1.0), "Ratio must be a float between 0 and 1");
033      }
034    }