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.jikesrvm;
014    
015    import org.vmmagic.pragma.RuntimeFinal;
016    
017    /**
018     * Flags that control the behavior of our virtual machine.
019     *
020     * Typically these are properties that can be set from the command line
021     * (and thus are NOT final).  All final properties should be
022     * declared in Configuration
023     */
024    public class Properties extends Options {
025    
026      // The VM class hierarchy is used in three ways:
027      //    - by boot image writer to create an executable vm image
028      //    - by tools that wish use VM classes for generic java programming
029      //    - by vm image itself, at execution time
030      // The following flags specify which behavior is desired.
031      //
032    
033      /**
034       * use classes for boot image generation? (see BootImageWriter)
035       */
036      @RuntimeFinal(false)
037      public static boolean writingBootImage;
038      /**
039       * use classes for generic java programming?
040       */
041      @RuntimeFinal(false)
042      public static boolean runningTool;
043      /**
044       * use classes for running actual VM?
045       */
046      @RuntimeFinal(true)
047      public static boolean runningVM;
048      /**
049       * are we in the boot-image-writing portion of boot-image-creation
050       */
051      @RuntimeFinal(false)
052      public static boolean writingImage = false;
053      /**
054       * is the running VM fully booted?
055       * Set by VM.boot when the VM is fully booted.
056       */
057      public static boolean fullyBooted = false;
058    
059      /**
060       * Is it safe to create a java.lang.Thread now?  Set by VM.boot at the
061       * appropriate time.
062       */
063      public static boolean safeToAllocateJavaThread = false;
064    
065      /**
066       * The following is set on by -X:verboseBoot= command line arg.
067       * When true, it generates messages to the sysWrite stream summarizing
068       * progress during the execution of VM.boot
069       */
070      public static int verboseBoot = 0;
071    
072      /**
073       * The following is set on by -verbose:class command line arg.
074       * When true, it generates messages to the sysWrite stream summarizing
075       * class loading activities
076       */
077      public static boolean verboseClassLoading = false;
078    
079      /**
080       * The following is set on by -verbose:jni command line arg.
081       * When true, it generates messages to the sysWrite stream summarizing
082       * jni activities
083       */
084      public static boolean verboseJNI = false;
085    
086      // Runtime subsystem tracing.
087      //
088      public static final boolean TraceDictionaries = false;
089      public static final boolean TraceStatics = false;
090      public static final boolean TraceFileSystem = false;
091      public static final boolean TraceThreads = false;
092      public static final boolean TraceStackTrace = false;
093      public static final boolean TraceExceptionDelivery = false;
094    
095      // Baseline compiler reference map tracing.
096      //
097      public static final boolean TraceStkMaps = false;
098      public static final boolean ReferenceMapsStatistics = false;
099      public static final boolean ReferenceMapsBitStatistics = false;
100    
101      public static final boolean TraceOnStackReplacement = false;
102    
103      /** How much farther? */
104      public static final int maxSystemTroubleRecursionDepthBeforeWeStopVMSysWrite = 3;
105    }