--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/CLHSDB.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/CLHSDB.java	Wed Jun 26 00:01:20 2013 +0100
@@ -31,13 +31,19 @@
 import java.util.*;
 
 public class CLHSDB {
+
+    public CLHSDB(JVMDebugger d) {
+        jvmDebugger = d;
+    }
+
     public static void main(String[] args) {
         new CLHSDB(args).run();
     }
 
-    private void run() {
-        // At this point, if pidText != null we are supposed to attach to it.
-        // Else, if execPath != null, it is the path of a jdk/bin/java
+    public void run() {
+        // If jvmDebugger is already set, we have been given a JVMDebugger.
+        // Otherwise, if pidText != null we are supposed to attach to it.
+        // Finally, if execPath != null, it is the path of a jdk/bin/java
         // and coreFilename is the pathname of a core file we are
         // supposed to attach to.
 
@@ -49,7 +55,9 @@
                 }
             });
 
-        if (pidText != null) {
+        if (jvmDebugger != null) {
+            attachDebugger(jvmDebugger);
+        } else if (pidText != null) {
             attachDebugger(pidText);
         } else if (execPath != null) {
             attachDebugger(execPath, coreFilename);
@@ -96,6 +104,7 @@
     // Internals only below this point
     //
     private HotSpotAgent agent;
+    private JVMDebugger jvmDebugger;
     private boolean      attached;
     // These had to be made data members because they are referenced in inner classes.
     private String pidText;
@@ -120,7 +129,7 @@
         case (1):
             if (args[0].equals("help") || args[0].equals("-help")) {
                 doUsage();
-                System.exit(0);
+                return;
             }
             // If all numbers, it is a PID to attach to
             // Else, it is a pathname to a .../bin/java for a core file.
@@ -142,10 +151,15 @@
         default:
             System.out.println("HSDB Error: Too many options specified");
             doUsage();
-            System.exit(1);
+            return;
         }
     }
 
+    private void attachDebugger(JVMDebugger d) {
+        agent.attach(d);
+        attached = true;
+     }
+
     /** NOTE we are in a different thread here than either the main
         thread or the Swing/AWT event handler thread, so we must be very
         careful when creating or removing widgets */

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/CommandProcessor.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/CommandProcessor.java	Wed Jun 26 00:01:20 2013 +0100
@@ -101,6 +101,9 @@
 import sun.jvm.hotspot.utilities.soql.JSJavaScriptEngine;
 
 public class CommandProcessor {
+
+    volatile boolean quit;
+
     public abstract static class DebuggerInterface {
         public abstract HotSpotAgent getAgent();
         public abstract boolean isAttached();
@@ -1135,7 +1138,7 @@
                     usage();
                 } else {
                     debugger.detach();
-                    System.exit(0);
+                    quit = true;
                 }
             }
         },
@@ -1714,7 +1717,7 @@
                         }
                         protected void quit() {
                             debugger.detach();
-                            System.exit(0);
+                            quit = true;
                         }
                         protected BufferedReader getInputReader() {
                             return in;
@@ -1781,7 +1784,7 @@
 
     public void run(boolean prompt) {
         // Process interactive commands.
-        while (true) {
+        while (!quit) {
             if (prompt) printPrompt();
             String ln = null;
             try {

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/HSDB.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/HSDB.java	Wed Jun 26 00:01:20 2013 +0100
@@ -59,8 +59,11 @@
   // Internals only below this point
   //
   private HotSpotAgent agent;
+  private JVMDebugger jvmDebugger;
   private JDesktopPane desktop;
   private boolean      attached;
+  private boolean      argError;
+  private JFrame frame;
   /** List <JMenuItem> */
   private java.util.List attachMenuItems;
   /** List <JMenuItem> */
@@ -85,6 +88,11 @@
     System.out.println("           path-to-corefile:        Debug this corefile.  The default is 'core'");
     System.out.println("        If no arguments are specified, you can select what to do from the GUI.\n");
     HotSpotAgent.showUsage();
+    argError = true;
+  }
+
+  public HSDB(JVMDebugger d) {
+    jvmDebugger = d;
   }
 
   private HSDB(String[] args) {
@@ -95,7 +103,6 @@
     case (1):
       if (args[0].equals("help") || args[0].equals("-help")) {
         doUsage();
-        System.exit(0);
       }
       // If all numbers, it is a PID to attach to
       // Else, it is a pathname to a .../bin/java for a core file.
@@ -117,24 +124,29 @@
     default:
       System.out.println("HSDB Error: Too many options specified");
       doUsage();
-      System.exit(1);
     }
   }
 
-  private void run() {
-    // At this point, if pidText != null we are supposed to attach to it.
-    // Else, if execPath != null, it is the path of a jdk/bin/java
-    // and coreFilename is the pathname of a core file we are
-    // supposed to attach to.
+  // close this tool without calling System.exit
+  protected void closeUI() {
+      workerThread.shutdown();
+      frame.dispose();
+  }
+
+  public void run() {
+    // Don't start the UI if there were bad arguments.
+    if (argError) {
+        return;
+    }
 
     agent = new HotSpotAgent();
     workerThread = new WorkerThread();
     attachMenuItems = new java.util.ArrayList();
     detachMenuItems = new java.util.ArrayList();
 
-    JFrame frame = new JFrame("HSDB - HotSpot Debugger");
+    frame = new JFrame("HSDB - HotSpot Debugger");
     frame.setSize(800, 600);
-    frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
+    frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
 
     JMenuBar menuBar = new JMenuBar();
 
@@ -197,7 +209,7 @@
     item = createMenuItem("Exit",
                             new ActionListener() {
                                 public void actionPerformed(ActionEvent e) {
-                                  System.exit(0);
+                                  closeUI();
                                 }
                               });
     item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X, ActionEvent.ALT_MASK));
@@ -406,7 +418,15 @@
         }
       });
 
-    if (pidText != null) {
+    // If jvmDebugger is already set, we have been given a JVMDebugger.
+    // Otherwise, if pidText != null we are supposed to attach to it.
+    // Finally, if execPath != null, it is the path of a jdk/bin/java
+    // and coreFilename is the pathname of a core file we are
+    // supposed to attach to.
+
+    if (jvmDebugger != null) {
+      attach(jvmDebugger);
+    } else if (pidText != null) {
       attach(pidText);
     } else if (execPath != null) {
       attach(execPath, coreFilename);
@@ -1113,6 +1133,12 @@
       });
   }
 
+  // Attach to existing JVMDebugger, which should be already attached to a core/process.
+  private void attach(JVMDebugger d) {
+    attached = true;
+    showThreadsDialog();
+  }
+
   /** NOTE we are in a different thread here than either the main
       thread or the Swing/AWT event handler thread, so we must be very
       careful when creating or removing widgets */

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/HotSpotAgent.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/HotSpotAgent.java	Wed Jun 26 00:01:20 2013 +0100
@@ -25,6 +25,8 @@
 package sun.jvm.hotspot;
 
 import java.rmi.RemoteException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
 
 import sun.jvm.hotspot.debugger.Debugger;
 import sun.jvm.hotspot.debugger.DebuggerException;
@@ -63,7 +65,6 @@
 
     private String os;
     private String cpu;
-    private String fileSep;
 
     // The system can work in several ways:
     //  - Attaching to local process
@@ -155,6 +156,14 @@
         go();
     }
 
+    /** This uses a JVMDebugger that is already attached to the core or process */
+    public synchronized void attach(JVMDebugger d)
+    throws DebuggerException {
+        debugger = d;
+        isServer = false;
+        go();
+    }
+
     /** This attaches to a "debug server" on a remote machine; this
       remote server has already attached to a process or opened a
       core file and is waiting for RMI calls on the Debugger object to
@@ -303,28 +312,37 @@
             // server, but not client attaching to server)
             //
 
-            try {
-                os  = PlatformInfo.getOS();
-                cpu = PlatformInfo.getCPU();
-            }
-            catch (UnsupportedPlatformException e) {
-                throw new DebuggerException(e);
-            }
-            fileSep = System.getProperty("file.separator");
+            // Handle existing or alternate JVMDebugger:
+            // these will set os, cpu independently of our PlatformInfo implementation.
+            String alternateDebugger = System.getProperty("sa.altDebugger");
+            if (debugger != null) {
+                setupDebuggerExisting();
+
+            } else if (alternateDebugger != null) {
+                setupDebuggerAlternate(alternateDebugger);
 
-            if (os.equals("solaris")) {
-                setupDebuggerSolaris();
-            } else if (os.equals("win32")) {
-                setupDebuggerWin32();
-            } else if (os.equals("linux")) {
-                setupDebuggerLinux();
-            } else if (os.equals("bsd")) {
-                setupDebuggerBsd();
-            } else if (os.equals("darwin")) {
-                setupDebuggerDarwin();
             } else {
-                // Add support for more operating systems here
-                throw new DebuggerException("Operating system " + os + " not yet supported");
+                // Otherwise, os, cpu are those of our current platform:
+                try {
+                    os  = PlatformInfo.getOS();
+                    cpu = PlatformInfo.getCPU();
+                } catch (UnsupportedPlatformException e) {
+                   throw new DebuggerException(e);
+                }
+                if (os.equals("solaris")) {
+                    setupDebuggerSolaris();
+                } else if (os.equals("win32")) {
+                    setupDebuggerWin32();
+                } else if (os.equals("linux")) {
+                    setupDebuggerLinux();
+                } else if (os.equals("bsd")) {
+                    setupDebuggerBsd();
+                } else if (os.equals("darwin")) {
+                    setupDebuggerDarwin();
+                } else {
+                    // Add support for more operating systems here
+                    throw new DebuggerException("Operating system " + os + " not yet supported");
+                }
             }
 
             if (isServer) {
@@ -423,6 +441,41 @@
     // OS-specific debugger setup/connect routines
     //
 
+    // Use the existing JVMDebugger, as passed to our constructor.
+    // Retrieve os and cpu from that debugger, not the current platform.
+    private void setupDebuggerExisting() {
+
+        os = debugger.getOS();
+        cpu = debugger.getCPU();
+        setupJVMLibNames(os);
+        machDesc = debugger.getMachineDescription();
+    }
+
+    // Given a classname, load an alternate implementation of JVMDebugger.
+    private void setupDebuggerAlternate(String alternateName) {
+
+        try {
+            Class c = Class.forName(alternateName);
+            Constructor cons = c.getConstructor();
+            debugger = (JVMDebugger) cons.newInstance();
+            attachDebugger();
+            setupDebuggerExisting();
+
+        } catch (ClassNotFoundException cnfe) {
+            throw new DebuggerException("Cannot find alternate SA Debugger: '" + alternateName + "'");
+        } catch (NoSuchMethodException nsme) {
+            throw new DebuggerException("Alternate SA Debugger: '" + alternateName + "' has missing constructor.");
+        } catch (InstantiationException ie) {
+            throw new DebuggerException("Alternate SA Debugger: '" + alternateName + "' fails to initialise: ", ie);
+        } catch (IllegalAccessException iae) {
+            throw new DebuggerException("Alternate SA Debugger: '" + alternateName + "' fails to initialise: ", iae);
+        } catch (InvocationTargetException iae) {
+            throw new DebuggerException("Alternate SA Debugger: '" + alternateName + "' fails to initialise: ", iae);
+        }
+
+        System.err.println("Loaded alternate HotSpot SA Debugger: " + alternateName);
+    }
+
     //
     // Solaris
     //
@@ -466,6 +519,11 @@
         debugger = new RemoteDebuggerClient(remote);
         machDesc = ((RemoteDebuggerClient) debugger).getMachineDescription();
         os = debugger.getOS();
+        setupJVMLibNames(os);
+        cpu = debugger.getCPU();
+    }
+
+    private void setupJVMLibNames(String os) {
         if (os.equals("solaris")) {
             setupJVMLibNamesSolaris();
         } else if (os.equals("win32")) {
@@ -479,8 +537,6 @@
         } else {
             throw new RuntimeException("Unknown OS type");
         }
-
-        cpu = debugger.getCPU();
     }
 
     private void setupJVMLibNamesSolaris() {

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/debugger/linux/LinuxAddress.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/debugger/linux/LinuxAddress.java	Wed Jun 26 00:01:20 2013 +0100
@@ -26,11 +26,11 @@
 
 import sun.jvm.hotspot.debugger.*;
 
-class LinuxAddress implements Address {
+public class LinuxAddress implements Address {
     protected LinuxDebugger debugger;
     protected long addr;
 
-    LinuxAddress(LinuxDebugger debugger, long addr) {
+    public LinuxAddress(LinuxDebugger debugger, long addr) {
         this.debugger = debugger;
         this.addr = addr;
     }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/debugger/linux/LinuxOopHandle.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/debugger/linux/LinuxOopHandle.java	Wed Jun 26 00:01:20 2013 +0100
@@ -26,8 +26,8 @@
 
 import sun.jvm.hotspot.debugger.*;
 
-class LinuxOopHandle extends LinuxAddress implements OopHandle {
-  LinuxOopHandle(LinuxDebugger debugger, long addr) {
+public class LinuxOopHandle extends LinuxAddress implements OopHandle {
+  public LinuxOopHandle(LinuxDebugger debugger, long addr) {
     super(debugger, addr);
   }
 

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/runtime/VM.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/runtime/VM.java	Wed Jun 26 00:01:20 2013 +0100
@@ -246,7 +246,7 @@
      }
   }
 
-  private static final boolean disableDerivedPrinterTableCheck;
+  private static final boolean disableDerivedPointerTableCheck;
   private static final Properties saProps;
 
   static {
@@ -256,12 +256,12 @@
        url = VM.class.getClassLoader().getResource("sa.properties");
        saProps.load(new BufferedInputStream(url.openStream()));
      } catch (Exception e) {
-       throw new RuntimeException("Unable to load properties  " +
+       System.err.println("Unable to load properties  " +
                                   (url == null ? "null" : url.toString()) +
                                   ": " + e.getMessage());
      }
 
-     disableDerivedPrinterTableCheck = System.getProperty("sun.jvm.hotspot.runtime.VM.disableDerivedPointerTableCheck") != null;
+     disableDerivedPointerTableCheck = System.getProperty("sun.jvm.hotspot.runtime.VM.disableDerivedPointerTableCheck") != null;
   }
 
   private VM(TypeDataBase db, JVMDebugger debugger, boolean isBigEndian) {
@@ -371,7 +371,8 @@
   /** This is used by the debugging system */
   public static void initialize(TypeDataBase db, JVMDebugger debugger) {
     if (soleInstance != null) {
-      throw new RuntimeException("Attempt to initialize VM twice");
+      // Using multiple SA Tool classes in the same process creates a call here.
+      return;
     }
     soleInstance = new VM(db, debugger, debugger.getMachineDescription().isBigEndian());
 
@@ -683,7 +684,7 @@
 
   /** Returns true if C2 derived pointer table should be used, false otherwise */
   public boolean useDerivedPointerTable() {
-    return !disableDerivedPrinterTableCheck;
+    return !disableDerivedPointerTableCheck;
   }
 
   /** Returns the code cache; should not be used if is core build */

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/ClassLoaderStats.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/ClassLoaderStats.java	Wed Jun 26 00:01:20 2013 +0100
@@ -41,6 +41,14 @@
 public class ClassLoaderStats extends Tool {
    boolean verbose = true;
 
+   public ClassLoaderStats() {
+      super();
+   }
+
+   public ClassLoaderStats(JVMDebugger d) {
+      super(d);
+   }
+
    public static void main(String[] args) {
       ClassLoaderStats cls = new ClassLoaderStats();
       cls.start(args);

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/FinalizerInfo.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/FinalizerInfo.java	Wed Jun 26 00:01:20 2013 +0100
@@ -24,6 +24,7 @@
 
 package sun.jvm.hotspot.tools;
 
+import sun.jvm.hotspot.debugger.JVMDebugger;
 import sun.jvm.hotspot.tools.*;
 
 import sun.jvm.hotspot.oops.*;
@@ -42,6 +43,15 @@
  * summary of these objects in the form of a histogram.
  */
 public class FinalizerInfo extends Tool {
+
+    public FinalizerInfo() {
+        super();
+    }
+
+    public FinalizerInfo(JVMDebugger d) {
+        super(d);
+    }
+
     public static void main(String[] args) {
         FinalizerInfo finfo = new FinalizerInfo();
         finfo.start(args);

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/FlagDumper.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/FlagDumper.java	Wed Jun 26 00:01:20 2013 +0100
@@ -25,10 +25,19 @@
 package sun.jvm.hotspot.tools;
 
 import java.io.PrintStream;
+import sun.jvm.hotspot.debugger.JVMDebugger;
 import sun.jvm.hotspot.runtime.*;
 
 public class FlagDumper extends Tool {
 
+    public FlagDumper() {
+        super();
+    }
+
+    public FlagDumper(JVMDebugger d) {
+        super(d);
+    }
+
    public void run() {
       VM.Flag[] flags = VM.getVM().getCommandLineFlags();
       PrintStream out = System.out;

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/HeapDumper.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/HeapDumper.java	Wed Jun 26 00:01:20 2013 +0100
@@ -25,6 +25,7 @@
 package sun.jvm.hotspot.tools;
 
 import sun.jvm.hotspot.utilities.HeapHprofBinWriter;
+import sun.jvm.hotspot.debugger.JVMDebugger;
 import java.io.IOException;
 
 /*
@@ -42,6 +43,11 @@
         this.dumpFile = dumpFile;
     }
 
+    public HeapDumper(String dumpFile, JVMDebugger d) {
+        super(d);
+        this.dumpFile = dumpFile;
+    }
+
     protected void printFlagsUsage() {
         System.out.println("    <no option>\tto dump heap to " +
             DEFAULT_DUMP_FILE);

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/HeapSummary.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/HeapSummary.java	Wed Jun 26 00:01:20 2013 +0100
@@ -29,12 +29,21 @@
 import sun.jvm.hotspot.gc_implementation.g1.*;
 import sun.jvm.hotspot.gc_implementation.parallelScavenge.*;
 import sun.jvm.hotspot.gc_implementation.shared.*;
+import sun.jvm.hotspot.debugger.JVMDebugger;
 import sun.jvm.hotspot.memory.*;
 import sun.jvm.hotspot.oops.*;
 import sun.jvm.hotspot.runtime.*;
 
 public class HeapSummary extends Tool {
 
+   public HeapSummary() {
+      super();
+   }
+
+   public HeapSummary(JVMDebugger d) {
+      super(d);
+   }
+
    public static void main(String[] args) {
       HeapSummary hs = new HeapSummary();
       hs.start(args);

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/JInfo.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/JInfo.java	Wed Jun 26 00:01:20 2013 +0100
@@ -25,12 +25,21 @@
 package sun.jvm.hotspot.tools;
 
 import sun.jvm.hotspot.runtime.*;
+import sun.jvm.hotspot.debugger.JVMDebugger;
 
 public class JInfo extends Tool {
+    public JInfo() {
+        super();
+    }
+
     public JInfo(int m) {
         mode = m;
     }
 
+    public JInfo(JVMDebugger d) {
+        super(d);
+    }
+
     protected boolean needsJavaPrefix() {
         return false;
     }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/JMap.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/JMap.java	Wed Jun 26 00:01:20 2013 +0100
@@ -25,6 +25,7 @@
 package sun.jvm.hotspot.tools;
 
 import java.io.*;
+import sun.jvm.hotspot.debugger.JVMDebugger;
 import sun.jvm.hotspot.utilities.*;
 
 public class JMap extends Tool {
@@ -36,6 +37,10 @@
         this(MODE_PMAP);
     }
 
+    public JMap(JVMDebugger d) {
+        super(d);
+    }
+
     protected boolean needsJavaPrefix() {
         return false;
     }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/JSnap.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/JSnap.java	Wed Jun 26 00:01:20 2013 +0100
@@ -25,9 +25,19 @@
 package sun.jvm.hotspot.tools;
 
 import java.io.*;
+import sun.jvm.hotspot.debugger.JVMDebugger;
 import sun.jvm.hotspot.runtime.*;
 
 public class JSnap extends Tool {
+
+    public JSnap() {
+        super();
+    }
+
+    public JSnap(JVMDebugger d) {
+        super(d);
+    }
+
     public void run() {
         final PrintStream out = System.out;
         if (PerfMemory.initialized()) {

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/JStack.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/JStack.java	Wed Jun 26 00:01:20 2013 +0100
@@ -24,6 +24,8 @@
 
 package sun.jvm.hotspot.tools;
 
+import sun.jvm.hotspot.debugger.JVMDebugger;
+
 public class JStack extends Tool {
     public JStack(boolean mixedMode, boolean concurrentLocks) {
         this.mixedMode = mixedMode;
@@ -34,6 +36,10 @@
         this(true, true);
     }
 
+    public JStack(JVMDebugger d) {
+        super(d);
+    }
+
     protected boolean needsJavaPrefix() {
         return false;
     }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/ObjectHistogram.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/ObjectHistogram.java	Wed Jun 26 00:01:20 2013 +0100
@@ -33,6 +33,14 @@
     an object histogram from a remote or crashed VM. */
 public class ObjectHistogram extends Tool {
 
+    public ObjectHistogram() {
+       super();
+    }
+
+    public ObjectHistogram(JVMDebugger d) {
+       super(d);
+    }
+
    public void run() {
       run(System.out, System.err);
    }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/PMap.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/PMap.java	Wed Jun 26 00:01:20 2013 +0100
@@ -31,6 +31,15 @@
 import sun.jvm.hotspot.runtime.*;
 
 public class PMap extends Tool {
+
+   public PMap() {
+       super();
+   }
+
+   public PMap(JVMDebugger d) {
+       super(d);
+   }
+
    public void run() {
       run(System.out);
    }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/PStack.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/PStack.java	Wed Jun 26 00:01:20 2013 +0100
@@ -45,6 +45,10 @@
       this(true, true);
    }
 
+   public PStack(JVMDebugger d) {
+      super(d);
+   }
+
    public void run() {
       run(System.out);
    }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/StackTrace.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/StackTrace.java	Wed Jun 26 00:01:20 2013 +0100
@@ -45,6 +45,16 @@
         run(System.out);
     }
 
+    public StackTrace(JVMDebugger d) {
+        super(d);
+    }
+
+    public StackTrace(JVMDebugger d, boolean v, boolean concurrentLocks) {
+        super(d);
+        this.verbose = v;
+        this.concurrentLocks = concurrentLocks;
+    }
+
     public void run(java.io.PrintStream tty) {
         // Ready to go with the database...
         try {

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/SysPropsDumper.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/SysPropsDumper.java	Wed Jun 26 00:01:20 2013 +0100
@@ -27,10 +27,19 @@
 import java.io.PrintStream;
 import java.util.*;
 
+import sun.jvm.hotspot.debugger.JVMDebugger;
 import sun.jvm.hotspot.runtime.*;
 
 public class SysPropsDumper extends Tool {
 
+   public SysPropsDumper() {
+      super();
+   }
+
+   public SysPropsDumper(JVMDebugger d) {
+      super(d);
+   }
+
    public void run() {
       Properties sysProps = VM.getVM().getSystemProperties();
       PrintStream out = System.out;

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/Tool.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/Tool.java	Wed Jun 26 00:01:20 2013 +0100
@@ -35,6 +35,7 @@
 
 public abstract class Tool implements Runnable {
    private HotSpotAgent agent;
+   private JVMDebugger jvmDebugger;
    private int debugeeType;
 
    // debugeeType is one of constants below
@@ -42,6 +43,13 @@
    protected static final int DEBUGEE_CORE   = 1;
    protected static final int DEBUGEE_REMOTE = 2;
 
+   public Tool() {
+   }
+
+   public Tool(JVMDebugger d) {
+      jvmDebugger = d;
+   }
+
    public String getName() {
       return getClass().getName();
    }
@@ -90,7 +98,6 @@
 
    protected void usage() {
       printUsage();
-      System.exit(1);
    }
 
    /*
@@ -106,13 +113,13 @@
    protected void stop() {
       if (agent != null) {
          agent.detach();
-         System.exit(0);
       }
    }
 
    protected void start(String[] args) {
       if ((args.length < 1) || (args.length > 2)) {
          usage();
+         return;
       }
 
       // Attempt to handle -h or -help or some invalid flag
@@ -185,13 +192,31 @@
         }
         if (e.getMessage() != null) {
           err.print(e.getMessage());
+          e.printStackTrace();
         }
         err.println();
-        System.exit(1);
+        return;
       }
 
       err.println("Debugger attached successfully.");
+      startInternal();
+   }
 
+   // When using an existing JVMDebugger.
+   public void start() {
+
+      if (jvmDebugger == null) {
+         throw new RuntimeException("Tool.start() called with no JVMDebugger set.");
+      }
+      agent = new HotSpotAgent();
+      agent.attach(jvmDebugger);
+      startInternal();
+   }
+
+   // Remains of the start mechanism, common to both start methods.
+   private void startInternal() {
+
+      PrintStream err = System.err;
       VM vm = VM.getVM();
       if (vm.isCore()) {
         err.println("Core build detected.");

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/jcore/ClassDump.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/jcore/ClassDump.java	Wed Jun 26 00:01:20 2013 +0100
@@ -25,6 +25,7 @@
 package sun.jvm.hotspot.tools.jcore;
 
 import java.io.*;
+import java.lang.reflect.Constructor;
 import java.util.jar.JarOutputStream;
 import java.util.jar.JarEntry;
 import java.util.jar.Manifest;
@@ -38,6 +39,16 @@
     private ClassFilter classFilter;
     private String      outputDirectory;
     private JarOutputStream jarStream;
+    private String      pkgList;
+
+    public ClassDump() {
+        super();
+    }
+
+    public ClassDump(JVMDebugger d, String pkgList) {
+        super(d);
+        this.pkgList = pkgList;
+    }
 
     public void setClassFilter(ClassFilter cf) {
         classFilter = cf;
@@ -63,6 +74,25 @@
     public void run() {
         // Ready to go with the database...
         try {
+            // The name of the filter always comes from a System property.
+            // If we have a pkgList, pass it, otherwise let the filter read
+            // its own System property for the list of classes.
+            String filterClassName = System.getProperty("sun.jvm.hotspot.tools.jcore.filter",
+                                                        "sun.jvm.hotspot.tools.jcore.PackageNameFilter");
+            try {
+                Class filterClass = Class.forName(filterClassName);
+                if (pkgList == null) {
+                    classFilter = (ClassFilter) filterClass.newInstance();
+                } else {
+                    Constructor con = filterClass.getConstructor(String.class);
+                    classFilter = (ClassFilter) con.newInstance(pkgList);
+                }
+            } catch(Exception exp) {
+                System.err.println("Warning: Can not create class filter!");
+            }
+
+            String outputDirectory = System.getProperty("sun.jvm.hotspot.tools.jcore.outputDir", ".");
+            setOutputDirectory(outputDirectory);
 
             // walk through the system dictionary
             SystemDictionary dict = VM.getVM().getSystemDictionary();
@@ -139,26 +169,8 @@
     }
 
     public static void main(String[] args) {
-        // load class filters
-        ClassFilter classFilter = null;
-        String filterClassName = System.getProperty("sun.jvm.hotspot.tools.jcore.filter");
-        if (filterClassName != null) {
-            try {
-                Class filterClass = Class.forName(filterClassName);
-                classFilter = (ClassFilter) filterClass.newInstance();
-            } catch(Exception exp) {
-                System.err.println("Warning: Can not create class filter!");
-            }
-        }
-
-        String outputDirectory = System.getProperty("sun.jvm.hotspot.tools.jcore.outputDir");
-        if (outputDirectory == null)
-            outputDirectory = ".";
-
 
         ClassDump cd = new ClassDump();
-        cd.setClassFilter(classFilter);
-        cd.setOutputDirectory(outputDirectory);
         cd.start(args);
         cd.stop();
     }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/soql/JSDB.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/soql/JSDB.java	Wed Jun 26 00:01:20 2013 +0100
@@ -24,12 +24,22 @@
 
 package sun.jvm.hotspot.tools.soql;
 
+import sun.jvm.hotspot.debugger.JVMDebugger;
 import sun.jvm.hotspot.tools.*;
 import sun.jvm.hotspot.utilities.*;
 import sun.jvm.hotspot.utilities.soql.*;
 
 /** This is command line JavaScript debugger console */
 public class JSDB extends Tool {
+
+    public JSDB() {
+        super();
+    }
+
+    public JSDB(JVMDebugger d) {
+        super(d);
+    }
+
     public static void main(String[] args) {
         JSDB jsdb = new JSDB();
         jsdb.start(args);

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/soql/SOQL.java	Tue Jun 25 14:11:57 2013 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/soql/SOQL.java	Wed Jun 26 00:01:20 2013 +0100
@@ -44,6 +44,14 @@
       soql.stop();
    }
 
+   public SOQL() {
+      super();
+   }
+
+   public SOQL(JVMDebugger d) {
+      super(d);
+   }
+
    protected SOQLEngine soqlEngine;
    protected BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    protected PrintStream out       = System.out;