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JPFVM.java

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

import de.fub.bytecode.*;
import de.fub.bytecode.classfile.*;
import gov.nasa.arc.ase.jpf.*;
import gov.nasa.arc.ase.util.Debug;
import java.util.*;

public class JPFVM {
  private static JPFVM jpfvm = null;
  private Hashtable loadedClasses = new Hashtable();
  private int nLoadedClasses = 0;

  public JPFVM() {
    setJPFVM(this);
  }  
  // returns the number of classes ever loaded
  public int countLoadedClasses() {
    return nLoadedClasses;
  }  
  public ClassInfo getClass(String name) {
    if (isLoaded(name)) return getLoadedClass(name);

    JavaClass jc = loadClassData(name);
    ClassInfo ci = new ClassInfo(jc);
    nLoadedClasses++;
    loadedClasses.put(name, ci);

    return ci;
  }  
  public static JPFVM getJPFVM() {
    if(jpfvm == null) {
      Debug.println(Debug.ERROR, "No JPFVM singleton created");
      System.exit(1);
    }

    return jpfvm;
  }  
  // returns the class info for an already loaded class
  public ClassInfo getLoadedClass(String name) {
    return (ClassInfo)loadedClasses.get(name);
  }  
  // checks if a class has already been loaded
  public boolean isLoaded(String name) {
    return loadedClasses.containsKey(name);
  }  
  // loads the internal rapresentation of a class
  public JavaClass loadClassData(String name) {
    JavaClass jc = null;
    if ((jc = Repository.lookupClass(name)) == null) {
      Debug.println(Debug.ERROR, "Could not load class: " + name);
      System.exit(1);
    }

    return jc;
  }  
  private static void setJPFVM(JPFVM j) {
    jpfvm = j;
  }  
}

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