---

DynamicArea.java

package gov.nasa.arc.ase.jpf.jvm;

import java.util.BitSet;
import gov.nasa.arc.ase.util.Debug;
import gov.nasa.arc.ase.jpf.Engine;
import gov.nasa.arc.ase.jpf.jvm.bytecode.Instruction;
//#ifdef RACE



//#endif RACE
//#ifdef MARK_N_SWEEP || REFERENCE_COUNT
import gov.nasa.arc.ase.util.BSet;
import gov.nasa.arc.ase.util.FalseBSet;
import gov.nasa.arc.ase.util.TrueBSet;
//#endif MARK_N_SWEEP || REFERENCE_COUNT

public class DynamicArea extends Area {
//#ifdef MARK_N_SWEEP
  
  /**
   * Used to store which objects are currently referenced.
   */
  public BitSet isUsed = null;
  
  public DynamicArea(DynamicArea da) {
    super(da);
    isUsed = da.isUsed;
  }  
//#endif MARK_N_SWEEP

  /**
   * Creates a new empty dynamic area.
   */
  public DynamicArea(KernelState ks) {
    super(ks, false);
  }  
  public Object clone() {
    return new DynamicArea(this);
  }  
//#ifdef MARK_N_SWEEP
  /**
   * Executes the mark and sweep garbage collection algorithm.
   */
  public void gc() {
    int length = elements.length;

    isUsed = new BitSet(length);

    ks.tl.mark();
    ks.sa.mark();

    int count = 0;

    for(int i = 0; i < length; i++)
      if(!isUsed.get(i)) {
    if(elements[i] != null) {
      count++;

      remove(i);
    }
      }

    Engine.getJPF().status.GCs += count;

    isUsed = null;
  }  
  public ElementInfo get(int index) {
    if(index == -1) return null;

    return super.get(index);
  }  
//#endif MARK_N_SWEEP

//#ifdef NO_DYNAMIC_SYMMETRY










//#else NO_DYNAMIC_SYMMETRY

  private int indexFor(ThreadInfo th) {
    Instruction pc = null;
    if(th != null) pc = th.getPC();

    DynamicMapIndex i = new DynamicMapIndex(pc,
//#ifdef THREAD_SYMMETRY
    th == null ? 0 : th.index, 
//#endif THREAD_SYMMETRY
    0);

    synchronized(DynamicMap.class) {
      if(!DynamicMap.hasEntry(i)) return DynamicMap.addEntry(i);

      int index = DynamicMap.getEntry(i);
      int length = elements.length;

      if(index < length)
    while(elements[index] != null) {
      i.next();

      if(!DynamicMap.hasEntry(i)) return DynamicMap.addEntry(i);

      index = DynamicMap.getEntry(i);

      if(index >= length) return index;
    }

      return index;
    }
  }  
//#endif NO_DYNAMIC_SYMMETRY

  public void log() {
    Debug.println(Debug.MESSAGE, "DA");
    for(int i = 0; i < elements.length; i++)
      if(elements[i] != null)
    elements[i].log();
  }  
  public void mark(int objref) {
    if(objref == -1) return;

    if(isUsed.get(objref)) return;

    isUsed.set(objref);

    elements[objref].mark();
  }  
  /**
   * Creates a new array object at a given address.
   */
  private int newArray(int index, String type, int size) {
    int ts = Types.getTypeSize(type);
    boolean ir = Types.isReference(type);

    Fields f = new Fields("["+type, ClassInfo.getClassInfo("java.lang.Object"),
    size * ts, size, false
//#ifdef MARK_N_SWEEP || REFERENCE_COUNT
    , ir ? (BSet)new TrueBSet() : (BSet)new FalseBSet()
//#endif MARK_N_SWEEP || REFERENCE_COUNT
    );
    Monitor m = new Monitor();
//#ifdef RACE







//#endif RACE

    ElementInfo e = new ElementInfo(f, m 
//#ifdef RACE

//#endif RACE
      );
    add(index, e);
    
    return index;
  }  
  /**
   * Creates a new array of the given type.
   */
  public int newArray(String type, int size, ThreadInfo th) {
    return newArray(indexFor(th), type, size);
  }  
  /**
   * Creates a new class object.
   */
  //** missing: this code does not exist yet.               **//
  public int newClass(String cname, ThreadInfo th) {
    return -1;
  }  
  /**
   * Creates a new object at the given address.
   */ 
  private int newObject(int index, ClassInfo ci) {
    ks.sa.get(ci.getName());

    Fields f = ci.createObjectFields();
    Monitor m = new Monitor();
//#ifdef RACE



//#endif RACE

    add(index, new ElementInfo(f, m
//#ifdef RACE

//#endif RACE
      ));

    return index;
  }  
  /**
   * Creates a new object of the given class.
   */
  public int newObject(ClassInfo ci, ThreadInfo th) {
    return newObject(indexFor(th), ci);
  }  
  /**
   * Creates a new string constant.
   */
  public int newString(String str, ThreadInfo th) {
    int length = str.length();
    int index = newObject(ClassInfo.getClassInfo("java.lang.String"), th);
    int value = newArray("C", length, th);

    ElementInfo e = get(index);
    e.setField("value", value);
    e.setField("offset", 0);
    e.setField("count", length);

    e = get(value);
    for(int i = 0; i < length; i++)
      e.setField(i, str.charAt(i));

    return index;
  }  
}

---