org.eclipse.jdt.debug/jdi/org/eclipse/jdi/internal/VirtualMachineImpl.java

/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdi.internal;


import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import com.ibm.icu.text.MessageFormat;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.eclipse.jdi.Bootstrap;
import org.eclipse.jdi.internal.connect.PacketReceiveManager;
import org.eclipse.jdi.internal.connect.PacketSendManager;
import org.eclipse.jdi.internal.event.EventQueueImpl;
import org.eclipse.jdi.internal.jdwp.JdwpCommandPacket;
import org.eclipse.jdi.internal.jdwp.JdwpObjectID;
import org.eclipse.jdi.internal.jdwp.JdwpReferenceTypeID;
import org.eclipse.jdi.internal.jdwp.JdwpReplyPacket;
import org.eclipse.jdi.internal.request.EventRequestManagerImpl;

import com.sun.jdi.BooleanValue;
import com.sun.jdi.ByteValue;
import com.sun.jdi.CharValue;
import com.sun.jdi.DoubleValue;
import com.sun.jdi.FloatValue;
import com.sun.jdi.IntegerValue;
import com.sun.jdi.LongValue;
import com.sun.jdi.ObjectCollectedException;
import com.sun.jdi.ShortValue;
import com.sun.jdi.StringReference;
import com.sun.jdi.VMDisconnectedException;
import com.sun.jdi.VirtualMachine;
import com.sun.jdi.connect.spi.Connection;
import com.sun.jdi.event.EventQueue;
import com.sun.jdi.request.EventRequestManager;

/**
 * This class implements the corresponding interfaces
 * declared by the JDI specification. See the com.sun.jdi package
 * for more information.
 *
 */
public class VirtualMachineImpl extends MirrorImpl implements VirtualMachine, org.eclipse.jdi.hcr.VirtualMachine, org.eclipse.jdi.VirtualMachine {
	/** Result flags for Classes Have Changed command. */
	public static final byte HCR_RELOAD_SUCCESS = 0;
	public static final byte HCR_RELOAD_FAILURE = 1;
	public static final byte HCR_RELOAD_IGNORED = 2;

	/* Indexes in HCR capabilities list.*/
	private static final int HCR_CAN_RELOAD_CLASSES = 0;
	private static final int HCR_CAN_GET_CLASS_VERSION = 1;
	private static final int HCR_CAN_DO_RETURN = 2;
	private static final int HCR_CAN_REENTER_ON_EXIT = 3;
	
	protected static final String JAVA_STRATUM_NAME= "Java"; //$NON-NLS-1$
	
	/** Timeout value for requests to VM if not overriden for a particular VM. */
	private int fRequestTimeout;
	/** Mapping of command codes to strings. */
	
	private static Map fgHCRResultMap = null;

	/** EventRequestManager that creates event objects on request. */
	private EventRequestManagerImpl fEventReqMgr;
	/** EventQueue that returns EventSets from the Virtual Manager. */
	private EventQueueImpl fEventQueue;
	
	/** If a launchingconnector is used, we store the process. */
	private Process fLaunchedProcess;
	
	/**
	 * The following field contains cached Mirrors.
	 * Note that these are optional: their only purpose is to speed up the debugger by
	 * being able to use the stored results of JDWP calls.
	 */
	private ValueCache fCachedReftypes = new ValueCache();
	private ValueCache fCachedObjects =  new ValueCache();

	/** The following are the stored results of JDWP calls. */
	private String fVersionDescription = null;	// Text information on the VM version.
	private int fJdwpMajorVersion;
	private int fJdwpMinorVersion;
	private String fVMVersion;	// Target VM JRE version, as in the java.version property.
	private String fVMName;		// Target VM name, as in the java.vm.name property.
	private boolean fGotIDSizes = false;
	private int fFieldIDSize;
	private int fMethodIDSize;
	private int fObjectIDSize;
	private int fReferenceTypeIDSize;
	private int fFrameIDSize;
       
	private boolean fGotCapabilities = false;
	private boolean fCanWatchFieldModification;
	private boolean fCanWatchFieldAccess;
	private boolean fCanGetBytecodes;
	private boolean fCanGetSyntheticAttribute;
	private boolean fCanGetOwnedMonitorInfo;
	private boolean fCanGetCurrentContendedMonitor;
	private boolean fCanGetMonitorInfo;
	private boolean fCanRedefineClasses;
	private boolean fCanAddMethod;
	private boolean fCanUnrestrictedlyRedefineClasses;
	private boolean fCanPopFrames;
	private boolean fCanUseInstanceFilters;
	private boolean fCanGetSourceDebugExtension;
	private boolean fCanRequestVMDeathEvent;
	private boolean fCanSetDefaultStratum;
	private boolean[] fHcrCapabilities = null;
	
	/*
	 * singletons for primitive types
	 */
	private BooleanTypeImpl fBooleanType;
	private ByteTypeImpl fByteType;
	private CharTypeImpl fCharType;
	private DoubleTypeImpl fDoubleType;
	private FloatTypeImpl fFloatType;
	private IntegerTypeImpl fIntegerType;
	private LongTypeImpl fLongType;
	private ShortTypeImpl fShortType;
	
	/**
	 * Disconnected flag
	 */
	private boolean fIsDisconnected = false;

	/**
	 * The name of the current default stratum.
	 */	
	private String fDefaultStratum;
    private PacketReceiveManager fPacketReceiveManager;
    private PacketSendManager fPacketSendManager;
	
	/** 
	 * Creates a new Virtual Machine.
	 */
	public VirtualMachineImpl(Connection connection) {
		super("VirtualMachine"); //$NON-NLS-1$
		fEventReqMgr = new EventRequestManagerImpl(this);
		fEventQueue = new EventQueueImpl(this);
		fRequestTimeout = ((VirtualMachineManagerImpl) Bootstrap.virtualMachineManager()).getGlobalRequestTimeout();
		
		fPacketReceiveManager = new PacketReceiveManager(connection, this);
		Thread receiveThread = new Thread(fPacketReceiveManager, JDIMessages.VirtualMachineImpl_0);  
        receiveThread.setDaemon(true);
		fPacketReceiveManager.setPartnerThread(receiveThread);
		receiveThread.start();
		
		fPacketSendManager = new PacketSendManager(connection);
		Thread sendThread = new Thread(fPacketSendManager, JDIMessages.VirtualMachineImpl_1); 
        sendThread.setDaemon(true);
		fPacketReceiveManager.setPartnerThread(sendThread);
		sendThread.start();
	}

	/** 
	 * @return Returns size of JDWP ID.
	 */
	public final int fieldIDSize() {
		return fFieldIDSize;
	}
	
	/** 
	 * @return Returns size of JDWP ID.
	 */
	public final int methodIDSize() {
		return fMethodIDSize;
	}
	
	/** 
	 * @return Returns size of JDWP ID.
	 */
	public final int objectIDSize() {
		return fObjectIDSize;
	}
	
	/** 
	 * @return Returns size of JDWP ID.
	 */
	public final int referenceTypeIDSize() {
		return fReferenceTypeIDSize;
	}
	
	/** 
	 * @return Returns size of JDWP ID.
	 */
	public final int frameIDSize() {
		return fFrameIDSize;
	}
	
	/** 
	 * @return Returns cached mirror object, or null if method is not in cache.
	 */
	public ReferenceTypeImpl getCachedMirror(JdwpReferenceTypeID ID) {
		return (ReferenceTypeImpl)fCachedReftypes.get(ID);
	}
	
	/** 
	 * @return Returns cached mirror object, or null if method is not in cache.
	 */
	public ObjectReferenceImpl getCachedMirror(JdwpObjectID ID) {
		return (ObjectReferenceImpl)fCachedObjects.get(ID);
	}
	
	/** 
	 * Adds mirror object to cache.
	 */
	public void addCachedMirror(ReferenceTypeImpl mirror) {
		fCachedReftypes.put(mirror.getRefTypeID(), mirror);
		// tbd: It is now yet possible to only ask for unload events for
		// classes that we know of due to a limitation in the J9 VM.
		// eventRequestManagerImpl().enableInternalClasUnloadEvent(mirror);
	}
	
	/** 
	 * Adds mirror object to cache.
	 */
	public void addCachedMirror(ObjectReferenceImpl mirror) {
		fCachedObjects.put(mirror.getObjectID(), mirror);
	}
	
	/**
	 * Flushes all stored Jdwp results.
	 */
	public void flushStoredJdwpResults() {
		// All known classes also become invalid.
		Iterator iter = fCachedReftypes.values().iterator();
		while (iter.hasNext()) {
			ReferenceTypeImpl refType = (ReferenceTypeImpl)iter.next();
			refType.flushStoredJdwpResults();
		}
			
		fVersionDescription = null;
		fGotIDSizes = false;
		fHcrCapabilities = null;
	}

	/*
	 * Removes a known class.
	 * A class/interface is known if we have ever received its ReferenceTypeID and we have
	 * not received an unload event for it.
	 */
	public final void removeKnownRefType(String signature) {
		List refTypeList = classesBySignature(signature);
		if (refTypeList.isEmpty())
			return;

		// If we have only one known class for this signature, we known that this is the class
		// to be removed.
		if (refTypeList.size() == 1) {
			ReferenceTypeImpl refType = (ReferenceTypeImpl)refTypeList.get(0);
			refType.flushStoredJdwpResults();
			fCachedReftypes.remove(refType.getRefTypeID());
			return;
		}
		
		// We have more than one known class for the signature, let's find the unloaded one(s).
		Iterator iter = refTypeList.iterator();
		while (iter.hasNext()) {
			ReferenceTypeImpl refType = (ReferenceTypeImpl)iter.next();
			boolean prepared= false;
			try {
				prepared= refType.isPrepared();
			} catch (ObjectCollectedException exception) {
				// The type is unloaded. Fall through
			}
			if (!prepared) {
				refType.flushStoredJdwpResults();
				iter.remove();
				fCachedReftypes.remove(refType.getRefTypeID());
			}
		}
	}

	/*
	 * @exception Throws UnsupportedOperationException if VM does not support J9 HCR.
	 */
	public void checkHCRSupported() throws UnsupportedOperationException {
		if (!isHCRSupported())
			throw new UnsupportedOperationException(MessageFormat.format(JDIMessages.VirtualMachineImpl_Target_VM__0__does_not_support_Hot_Code_Replacement_1, new String[]{name()})); 
	}
	
	/*
	 * Returns whether J9 HCR is supported
	 */
	public boolean isHCRSupported() throws UnsupportedOperationException {
		return name().equals("j9"); //$NON-NLS-1$
	}	

	/*
	 * @return Returns Manager for receiving packets from the Virtual Machine.
	 */
	public final PacketReceiveManager packetReceiveManager() {
		return fPacketReceiveManager;
	}

	/*
	 * @return Returns Manager for sending packets to the Virtual Machine.
	 */
	public final PacketSendManager packetSendManager() {
		/*
		 * Before we send out first bytes to the VM by JDI calls, we need some initial requests:
		 * - Get the sizes of the IDs (fieldID, method ID etc.) that the VM uses;
		 * - Request class prepare and unload events. We used these to cache classes/interfaces and map their signatures.
		 */
		if (!fGotIDSizes) {
			getIDSizes();
			if (!fGotIDSizes) {	// We can't do much without them.
				disconnectVM();
				throw new VMDisconnectedException(JDIMessages.VirtualMachineImpl_Failed_to_get_ID_sizes_2); 
			}

			// tbd: This call should be moved to addKnownRefType() when it can be made specific
			// for a referencetype.
			eventRequestManagerImpl().enableInternalClasUnloadEvent();
		}

		return fPacketSendManager;
	}

	/**
	 * Returns all loaded types (classes, interfaces, and array types).
	 * For each loaded type in the target VM a ReferenceType will be placed in the returned list.
	 */
	public List allClasses() {
		// Note that this information should not be cached.
		initJdwpRequest();
		try {
			boolean withGenericSignature= virtualMachineImpl().isJdwpVersionGreaterOrEqual(1, 5);
			int jdwpCommand= withGenericSignature ? JdwpCommandPacket.VM_ALL_CLASSES_WITH_GENERIC : JdwpCommandPacket.VM_ALL_CLASSES;
		 	JdwpReplyPacket replyPacket = requestVM(jdwpCommand);
			defaultReplyErrorHandler(replyPacket.errorCode());
			DataInputStream replyData = replyPacket.dataInStream();
			int nrOfElements = readInt("elements", replyData); //$NON-NLS-1$
			List elements = new ArrayList(nrOfElements);
			for (int i = 0; i < nrOfElements; i++) {
				ReferenceTypeImpl elt = ReferenceTypeImpl.readWithTypeTagAndSignature(this, withGenericSignature, replyData);
				if (elt == null) {
					continue;
				}
				readInt("status", ReferenceTypeImpl.classStatusStrings(), replyData); //$NON-NLS-1$
				elements.add(elt);
			}
			return elements;
		} catch (IOException e) {
			defaultIOExceptionHandler(e);
			return null;
		} finally {
			handledJdwpRequest();
		}

	}

	/**
	 * @return Returns an iterator over all loaded classes.
	 */
	protected final Iterator allRefTypes() {
		return allClasses().iterator();
	}

	/**
	 * @return Returns an iterator over all cached classes.
	 */
	protected final Iterator allCachedRefTypes() {
		return fCachedReftypes.values().iterator();
	}

	/**
	 * Returns a list of the currently running threads.
	 * For each running thread in the target VM, a ThreadReference that mirrors it is placed in the list.
	 */
	public List allThreads() {
		// Note that this information should not be cached.
		initJdwpRequest();
		try {
			JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.VM_ALL_THREADS);
			defaultReplyErrorHandler(replyPacket.errorCode());
			DataInputStream replyData = replyPacket.dataInStream();
			int nrOfElements = readInt("elements", replyData); //$NON-NLS-1$
			List elements = new ArrayList(nrOfElements);
			for (int i = 0; i < nrOfElements; i++) {
				ThreadReferenceImpl elt = ThreadReferenceImpl.read(this, replyData);
				if (elt == null) {
					continue;
				}
				elements.add(elt);
			}
			return elements;
		} catch (IOException e) {
			defaultIOExceptionHandler(e);
			return null;
		} finally {
			handledJdwpRequest();
		}
	}
			
	/**
	 * Retrieve this VM's capabilities. 
	 */
	public void getCapabilities() {
		if (fGotCapabilities)
			return;
		
		int command =  JdwpCommandPacket.VM_CAPABILITIES;
		if (isJdwpVersionGreaterOrEqual(1, 4)) {
			command = JdwpCommandPacket.VM_CAPABILITIES_NEW;
		}
		
		initJdwpRequest();
		try {
			JdwpReplyPacket replyPacket = requestVM(command);
			defaultReplyErrorHandler(replyPacket.errorCode());
			DataInputStream replyData = replyPacket.dataInStream();
		
			fCanWatchFieldModification = readBoolean("watch field modification", replyData); //$NON-NLS-1$
			fCanWatchFieldAccess = readBoolean("watch field access", replyData); //$NON-NLS-1$
			fCanGetBytecodes = readBoolean("get bytecodes", replyData); //$NON-NLS-1$
			fCanGetSyntheticAttribute = readBoolean("synth. attr", replyData); //$NON-NLS-1$
			fCanGetOwnedMonitorInfo = readBoolean("owned monitor info", replyData); //$NON-NLS-1$
			fCanGetCurrentContendedMonitor = readBoolean("curr. contended monitor", replyData); //$NON-NLS-1$
			fCanGetMonitorInfo = readBoolean("monitor info", replyData); //$NON-NLS-1$
			if (command == JdwpCommandPacket.VM_CAPABILITIES_NEW) {
				// extended capabilities
				fCanRedefineClasses = readBoolean("redefine classes", replyData); //$NON-NLS-1$
				fCanAddMethod = readBoolean("add method", replyData); //$NON-NLS-1$
				fCanUnrestrictedlyRedefineClasses = readBoolean("unrestrictedly redefine classes", replyData); //$NON-NLS-1$
				fCanPopFrames = readBoolean("pop frames", replyData); //$NON-NLS-1$
				fCanUseInstanceFilters = readBoolean("use instance filters", replyData); //$NON-NLS-1$
				fCanGetSourceDebugExtension = readBoolean("get source debug extension", replyData); //$NON-NLS-1$
				fCanRequestVMDeathEvent = readBoolean("request vm death", replyData); //$NON-NLS-1$
				fCanSetDefaultStratum= readBoolean("set default stratum", replyData); //$NON-NLS-1$
			} else {
				fCanRedefineClasses = false;
				fCanAddMethod = false;
				fCanUnrestrictedlyRedefineClasses = false;
				fCanPopFrames = false;			
				fCanUseInstanceFilters = false;
				fCanGetSourceDebugExtension = false;
				fCanRequestVMDeathEvent = false;
				fCanSetDefaultStratum= false;
			}
			fGotCapabilities = true;
		} catch (IOException e) {
			fGotIDSizes = false;
			defaultIOExceptionHandler(e);
		} finally {
			handledJdwpRequest();
		}
	}
	
	/**
	 * @return Returns true if this implementation supports the retrieval of a method's bytecodes.
	 */
	public boolean canGetBytecodes() {
		getCapabilities();
		return fCanGetBytecodes;
	}
		
	/**
	 * @return Returns true if this implementation supports the retrieval of the monitor for which a thread is currently waiting.
	 */
	public boolean canGetCurrentContendedMonitor() {
		getCapabilities();
		return fCanGetCurrentContendedMonitor;
	}
	
	/**
	 * @return Returns true if this implementation supports the retrieval of the monitor information for an object.
	 */
	public boolean canGetMonitorInfo() {
		getCapabilities();
		return fCanGetMonitorInfo;
	}
	
	/**
	 * @return Returns true if this implementation supports the retrieval of the monitors owned by a thread.
	 */
	public boolean canGetOwnedMonitorInfo() {
		getCapabilities();
		return fCanGetOwnedMonitorInfo;
	}
	
	/**
	 * @return Returns true if this implementation supports the query of the synthetic attribute of a method or field.

	 */
	public boolean canGetSyntheticAttribute() {
		getCapabilities();
		return fCanGetSyntheticAttribute;
	}
	
	/**
	 * @return Returns true if this implementation supports watchpoints for field access.
	 */
	public boolean canWatchFieldAccess() {
		getCapabilities();
		return fCanWatchFieldAccess;
	}
	
	/**
	 * @return Returns true if this implementation supports watchpoints for field modification.
	 */
	public boolean canWatchFieldModification() {
		getCapabilities();
		return fCanWatchFieldModification;
	}
	
	/**
	 * @return Returns the loaded reference types that match a given signature.
	 */
	public List classesBySignature(String signature) {
		// Note that this information should not be cached.
		initJdwpRequest();
		try {
			ByteArrayOutputStream outBytes = new ByteArrayOutputStream();
			DataOutputStream outData = new DataOutputStream(outBytes);
			writeString(signature, "signature", outData); //$NON-NLS-1$

			JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.VM_CLASSES_BY_SIGNATURE, outBytes);
			defaultReplyErrorHandler(replyPacket.errorCode());
			DataInputStream replyData = replyPacket.dataInStream();
			int nrOfElements = readInt("elements", replyData); //$NON-NLS-1$
			List elements = new ArrayList(nrOfElements);
			for (int i = 0; i < nrOfElements; i++) {
				ReferenceTypeImpl elt = ReferenceTypeImpl.readWithTypeTag(this, replyData);
				readInt("status", ReferenceTypeImpl.classStatusStrings(), replyData); //$NON-NLS-1$
				if (elt == null) {
					continue;
				}
				elements.add(elt);
			}
			return elements;
		} catch (IOException e) {
			defaultIOExceptionHandler(e);
			return null;
		} finally {
			handledJdwpRequest();
		}
	}
	
	/**
	 * @return Returns the loaded reference types that match a given name.
	 */
	public List classesByName(String name) {
		String signature = TypeImpl.classNameToSignature(name);
		return classesBySignature(signature);
	}
	
	/**
	 * Invalidates this virtual machine mirror.
	 */
	public void dispose() {
		initJdwpRequest();
		try {
			requestVM(JdwpCommandPacket.VM_DISPOSE);
			disconnectVM();
		} catch (VMDisconnectedException e) {
			// The VM can exit before we receive the reply.
		} finally {
			handledJdwpRequest();
		}
	}
	
	/**
	 * @return Returns EventQueue that returns EventSets from the Virtual Manager.
	 */
	public EventQueue eventQueue() {
		return fEventQueue;
	}

	/**
	 * @return Returns EventRequestManager that creates all event objects on request.
	 */
	public EventRequestManager eventRequestManager() {
		return fEventReqMgr;
	}
	
	/**
	 * @return Returns EventRequestManagerImpl that creates all event objects on request.
	 */
	public EventRequestManagerImpl eventRequestManagerImpl() {
		return fEventReqMgr;
	}

	/**
	 * Causes the mirrored VM to terminate with the given error code. 
	 */
	public void exit(int exitCode) {
		initJdwpRequest();
		try {
			ByteArrayOutputStream outBytes = new ByteArrayOutputStream();
			DataOutputStream outData = new DataOutputStream(outBytes);
			writeInt(exitCode, "exit code", outData); //$NON-NLS-1$
			requestVM(JdwpCommandPacket.VM_EXIT, outBytes);
			disconnectVM();
		} catch (VMDisconnectedException e) {
			// The VM can exit before we receive the reply.
		} catch (IOException e) {
			defaultIOExceptionHandler(e);
		} finally {
			handledJdwpRequest();
		}
	}

	/**
	 * @return Returns newly created ByteValue for the given value. 
	 */
	public ByteValue mirrorOf(byte value) {
		return new ByteValueImpl(virtualMachineImpl(), new Byte(value));
	}

	/**
	 * @return Returns newly created CharValue for the given value. 
	 */
	public CharValue mirrorOf(char value) {
		return new CharValueImpl(virtualMachineImpl(), new Character(value));
	}

	/**
	 * @return Returns newly created DoubleValue for the given value. 
	 */
	public DoubleValue mirrorOf(double value) {
		return new DoubleValueImpl(virtualMachineImpl(), new Double(value));
	}

	/**
	 * @return Returns newly created FloatValue for the given value. 
	 */
	public FloatValue mirrorOf(float value) {
		return new FloatValueImpl(virtualMachineImpl(), new Float(value));
	}

	/**
	 * @return Returns newly created IntegerValue for the given value. 
	 */
	public IntegerValue mirrorOf(int value) {
		return new IntegerValueImpl(virtualMachineImpl(), new Integer(value));
	}

	/**
	 * @return Returns newly created LongValue for the given value. 
	 */
	public LongValue mirrorOf(long value) {
		return new LongValueImpl(virtualMachineImpl(), new Long(value));
	}

	/**
	 * @return Returns newly created ShortValue for the given value. 
	 */
	public ShortValue mirrorOf(short value) {
		return new ShortValueImpl(virtualMachineImpl(), new Short(value));
	}

	/**
	 * @return Returns newly created BooleanValue for the given value. 
	 */
	public BooleanValue mirrorOf(boolean value) {
		return new BooleanValueImpl(virtualMachineImpl(), Boolean.valueOf(value));
	}
		
	/**
	 * @return Returns newly created StringReference for the given value. 
	 */
	public StringReference mirrorOf(String value) {
		initJdwpRequest();
		try {
			ByteArrayOutputStream outBytes = new ByteArrayOutputStream();
			DataOutputStream outData = new DataOutputStream(outBytes);
			writeString(value, "string value", outData); //$NON-NLS-1$
	
			JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.VM_CREATE_STRING, outBytes);
			defaultReplyErrorHandler(replyPacket.errorCode());
			
			DataInputStream replyData = replyPacket.dataInStream();
			StringReference result = StringReferenceImpl.read(this, replyData);
			return result;
		} catch (IOException e) {
			defaultIOExceptionHandler(e);
			return null;
		} finally {
			handledJdwpRequest();
		}
	}

	/**
	 * @return Returns the Process object for this virtual machine if launched by a LaunchingConnector.
	 */
	public Process process() {
	 	return fLaunchedProcess;
	}
	 	
	/**
	 * Sets Process object for this virtual machine if launched by a LaunchingConnector.
	 */
	public void setLaunchedProcess(Process proc) {
		fLaunchedProcess = proc;
	}
	
	/** 
	 * Continues the execution of the application running in this virtual machine. 
	 */
	public void resume() {
		initJdwpRequest();
		try {
			resetThreadEventFlags();
			JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.VM_RESUME);
			defaultReplyErrorHandler(replyPacket.errorCode());
		} finally {
			handledJdwpRequest();
		}
	}
		
	public void setDebugTraceMode(int traceFlags) {
		// We don't have trace info.
	}

	/** 
	 * Suspends all threads.
	 */
	public void suspend() {
		initJdwpRequest();
		try {
			JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.VM_SUSPEND);
			defaultReplyErrorHandler(replyPacket.errorCode());
		} finally {
			handledJdwpRequest();
		}
	}
		
	public List topLevelThreadGroups() {
		// Note that this information should not be cached.
		initJdwpRequest();
		try {
			JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.VM_TOP_LEVEL_THREAD_GROUPS);
			defaultReplyErrorHandler(replyPacket.errorCode());
			
			DataInputStream replyData = replyPacket.dataInStream();
			int nrGroups = readInt("nr of groups", replyData); //$NON-NLS-1$
			ArrayList result = new ArrayList(nrGroups);
			for (int i = 0; i < nrGroups; i++) {
				ThreadGroupReferenceImpl threadGroup = ThreadGroupReferenceImpl.read(this, replyData);
				result.add(threadGroup);
			}
			return result;
		} catch (IOException e) {
			defaultIOExceptionHandler(e);
			return null;
		} finally {
			handledJdwpRequest();
		}
	}

	/** 
	 * @return Returns the name of the target VM as reported by the property java.vm.name.
	 */
	public String name() {
		getVersionInfo();
		return fVMName;
	}
		
	/** 
	 * @return Returns the version of the Java Runtime Environment in the target VM as reported by the property java.version.
	 */
	public String version() {
		getVersionInfo();
		return fVMVersion;
	}
			
	/** 
	 * @return Returns text information on the target VM and the debugger support that mirrors it. 
	 */
	public String description() {
		getVersionInfo();
		return fVersionDescription;
	}
			
	/**
	 * Reset event flags of all threads.
	 */
	private void resetThreadEventFlags() {
		Iterator iter = allThreads().iterator();
		ThreadReferenceImpl thread;
		while (iter.hasNext()) {
			thread = (ThreadReferenceImpl)iter.next();
			thread.resetEventFlags();
		}
	}

	/**
	 * Request and fetch ID sizes of Virtual Machine.
	 */
	private void getIDSizes() {
		if (fGotIDSizes)
			return;

		/*
		 * fGotIDSizes must first be assigned true to prevent an invinite loop
		 * because getIDSizes() calls requestVM which calls packetSendManager.
		 */
		fGotIDSizes = true;
		 
		// We use a different mirror to avoid having verbose output mixed with the initiating command.
		MirrorImpl mirror = new VoidValueImpl(this);
		
		mirror.initJdwpRequest();
		try {
			JdwpReplyPacket replyPacket = mirror.requestVM(JdwpCommandPacket.VM_ID_SIZES);
			mirror.defaultReplyErrorHandler(replyPacket.errorCode());
			DataInputStream replyData = replyPacket.dataInStream();
		
			fFieldIDSize = mirror.readInt("field ID size", replyData); //$NON-NLS-1$
			fMethodIDSize = mirror.readInt("method ID size", replyData); //$NON-NLS-1$
			fObjectIDSize = mirror.readInt("object ID size", replyData); //$NON-NLS-1$
			fReferenceTypeIDSize = mirror.readInt("refType ID size", replyData); //$NON-NLS-1$
			fFrameIDSize = mirror.readInt("frame ID size", replyData); //$NON-NLS-1$
		} catch (IOException e) {
			fGotIDSizes = false;
			mirror.defaultIOExceptionHandler(e);
		} finally {
			mirror.handledJdwpRequest();
		}
	}
	
	/**
	 * Retrieves version info of the VM.
	 */
	public void getVersionInfo() {
		if (fVersionDescription != null)
			return;
			
		initJdwpRequest();
		try {
			JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.VM_VERSION);
			defaultReplyErrorHandler(replyPacket.errorCode());
			DataInputStream replyData = replyPacket.dataInStream();
		
			fVersionDescription = readString("version descr.", replyData); //$NON-NLS-1$
			fJdwpMajorVersion = readInt("major version", replyData); //$NON-NLS-1$
			fJdwpMinorVersion = readInt("minor version", replyData); //$NON-NLS-1$
			fVMVersion = readString("version", replyData); //$NON-NLS-1$
			fVMName = readString("name", replyData); //$NON-NLS-1$
			
			if ((fVMName != null) && fVMName.equals("KVM")) { //$NON-NLS-1$
				// KVM requires class preparation events in order
				// to resolve things correctly
				eventRequestManagerImpl().enableInternalClassPrepareEvent();
			}

		} catch (IOException e) {
e.printStackTrace();		    
			fVersionDescription = null;
			defaultIOExceptionHandler(e);
		} finally {
			handledJdwpRequest();
		}
	}
		
	/**
	 * Retrieves the HCR capabilities of the VM.
	 */
	public void getHCRCapabilities() {
		if (fHcrCapabilities != null)
			return;
		fHcrCapabilities = new boolean[HCR_CAN_REENTER_ON_EXIT + 1];
		
		if (isHCRSupported()) {
			initJdwpRequest();
			try {
				JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.HCR_CAPABILITIES);
				defaultReplyErrorHandler(replyPacket.errorCode());
				DataInputStream replyData = replyPacket.dataInStream();
			
				fHcrCapabilities[HCR_CAN_RELOAD_CLASSES] = readBoolean("reload classes", replyData); //$NON-NLS-1$
				fHcrCapabilities[HCR_CAN_GET_CLASS_VERSION] = readBoolean("get class version", replyData); //$NON-NLS-1$
				fHcrCapabilities[HCR_CAN_DO_RETURN] = readBoolean("do return", replyData); //$NON-NLS-1$
				fHcrCapabilities[HCR_CAN_REENTER_ON_EXIT] = readBoolean("reenter on exit", replyData); //$NON-NLS-1$
			} catch (IOException e) {
				fHcrCapabilities = null;
				defaultIOExceptionHandler(e);
			} finally {
				handledJdwpRequest();
			}
		} else {
			for (int i = 0; i < fHcrCapabilities.length; i++) {
				fHcrCapabilities[i] = false;
			}
		}
	}
	
	/**
	 * @return Returns Whether VM can deal with the 'Classes have Changed' command.
	 */
	public boolean canReloadClasses() {
		getHCRCapabilities();
		return fHcrCapabilities[HCR_CAN_RELOAD_CLASSES];
	}
	
	/**
	 * @return Returns Whether VM can get the version of a given class file.
	 */
	public boolean canGetClassFileVersion() {
		getHCRCapabilities();
		return fHcrCapabilities[HCR_CAN_GET_CLASS_VERSION];
	}
	
	/**
	 * @return Returns Whether VM can do a return in the middle of executing a method.
	 */
	public boolean canDoReturn() {
		getHCRCapabilities();
		return fHcrCapabilities[HCR_CAN_DO_RETURN];
	}
	
	/**
	 * @return Returns Whether VM can reenter a method on exit.
	 */
	public boolean canReenterOnExit() {
		getHCRCapabilities();
		return fHcrCapabilities[HCR_CAN_REENTER_ON_EXIT];
	}
	
	/**
	 * Notify the VM that classes have changed due to Hot Code Replacement.
	 * @return Returns RELOAD_SUCCESS, RELOAD_FAILURE or RELOAD_IGNORED.
	 */
	public int classesHaveChanged(String[] names) {
		checkHCRSupported();
		// We convert the class/interface names to signatures.
		String[] signatures = new String[names.length];
		
		initJdwpRequest();
		try {
			ByteArrayOutputStream outBytes = new ByteArrayOutputStream();
			DataOutputStream outData = new DataOutputStream(outBytes);
			writeInt(names.length, "length", outData); //$NON-NLS-1$
			for (int i = 0; i < names.length; i++) {
				signatures[i] = TypeImpl.classNameToSignature(names[i]);
				writeString(signatures[i], "signature", outData); //$NON-NLS-1$
			}
		
			JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.HCR_CLASSES_HAVE_CHANGED, outBytes);
			defaultReplyErrorHandler(replyPacket.errorCode());
			DataInputStream replyData = replyPacket.dataInStream();
		
			byte resultFlag = readByte("result", resultHCRMap(), replyData); //$NON-NLS-1$
			switch (resultFlag) {
				case HCR_RELOAD_SUCCESS:
					return RELOAD_SUCCESS;
				case HCR_RELOAD_FAILURE:
					return RELOAD_FAILURE;
				case HCR_RELOAD_IGNORED:
					return RELOAD_IGNORED;
			}
			throw new InternalError(JDIMessages.VirtualMachineImpl_Invalid_result_flag_in_Classes_Have_Changed_response___3 + resultFlag + JDIMessages.VirtualMachineImpl__4); // 
		} catch (IOException e) {
			defaultIOExceptionHandler(e);
			return 0;
		} finally {
			handledJdwpRequest();
		}
	}

	/**
	 * @return Returns description of Mirror object.
	 */
	public String toString() {
		try {
			return name();
		} catch (Exception e) {
			return fDescription;
		}
	}

	/**
	 * Retrieves constant mappings.
	 */
	public static void getConstantMaps() {
		if (fgHCRResultMap != null) {
			return;
		}
		
		Field[] fields = VirtualMachineImpl.class.getDeclaredFields();
		fgHCRResultMap = new HashMap();
		for (int i = 0; i < fields.length; i++) {
			Field field = fields[i];
			if ((field.getModifiers() & Modifier.PUBLIC) == 0 || (field.getModifiers() & Modifier.STATIC) == 0 || (field.getModifiers() & Modifier.FINAL) == 0) {
				continue;
			}
				
			try {
				String name = field.getName();
				if (name.startsWith("HCR_RELOAD_")) { //$NON-NLS-1$
					Integer intValue = new Integer(field.getInt(null));
					name = name.substring(4);
					fgHCRResultMap.put(intValue, name);
				}
			} catch (IllegalAccessException e) {
				// Will not occur for own class.
			} catch (IllegalArgumentException e) {
				// Should not occur.
				// We should take care that all public static final constants
				// in this class are numbers that are convertible to int.
			}
		}
	}
	
	/**
	 * @return Returns a map with string representations of tags.
	 */
	 public static Map resultHCRMap() {
	 	getConstantMaps();
	 	return fgHCRResultMap;
	 }
	 
	/**
	 * Sets request timeout in ms.
	 */
	public void setRequestTimeout(int timeout) {
		fRequestTimeout = timeout;
	}
	
	/**
	 * @return Returns request timeout in ms.
	 */
	public int getRequestTimeout() {
		return fRequestTimeout;
	}
	
	/**
	 * Returns whether the JDWP version is greater
	 * than or equal to the specified major/minor
	 * version numbers.
	 * 
	 * @return whether the JDWP version is greater
	 * than or equal to the specified major/minor
	 * version numbers
	 */
	public boolean isJdwpVersionGreaterOrEqual(int major, int minor) {
		getVersionInfo();
		return (fJdwpMajorVersion > major) ||
			(fJdwpMajorVersion == major && fJdwpMinorVersion >= minor);
	}
	
	/*
	 * @see VirtualMachine#redefineClasses(Map)
	 */
	public void redefineClasses(Map typesToBytes) {
		if (!canRedefineClasses()) {
			throw new UnsupportedOperationException();
		}
		
		initJdwpRequest();
		try {
			ByteArrayOutputStream outBytes = new ByteArrayOutputStream();
			DataOutputStream outData = new DataOutputStream(outBytes);
			writeInt(typesToBytes.size(), "classes", outData); //$NON-NLS-1$
			
			Set types = typesToBytes.keySet();
			Iterator iter = types.iterator();
			while (iter.hasNext()) {
				ReferenceTypeImpl type = (ReferenceTypeImpl) iter.next();
				type.write(this, outData);
				byte[] bytes = (byte[]) typesToBytes.get(type);
				writeInt(bytes.length, "classfile", outData); //$NON-NLS-1$
				for (int i=0; i < bytes.length; i++) {
					writeByte(bytes[i], "classByte", outData); //$NON-NLS-1$
				}
				fCachedReftypes.remove(type.getRefTypeID()); // flush local cache of redefined types
			}
			
			JdwpReplyPacket reply = requestVM(JdwpCommandPacket.VM_REDEFINE_CLASSES, outBytes);
			switch (reply.errorCode()) {
				case JdwpReplyPacket.UNSUPPORTED_VERSION:
					throw new UnsupportedClassVersionError();
				case JdwpReplyPacket.INVALID_CLASS_FORMAT:
					throw new ClassFormatError();
				case JdwpReplyPacket.CIRCULAR_CLASS_DEFINITION:
					throw new ClassCircularityError();
				case JdwpReplyPacket.FAILS_VERIFICATION:
					throw new VerifyError();
				case JdwpReplyPacket.NAMES_DONT_MATCH:
					throw new NoClassDefFoundError();
				case JdwpReplyPacket.ADD_METHOD_NOT_IMPLEMENTED:
					throw new UnsupportedOperationException(JDIMessages.VirtualMachineImpl_Add_method_not_implemented_1); 
				case JdwpReplyPacket.SCHEMA_CHANGE_NOT_IMPLEMENTED:
					throw new UnsupportedOperationException(JDIMessages.VirtualMachineImpl_Scheme_change_not_implemented_2); 
				case JdwpReplyPacket.HIERARCHY_CHANGE_NOT_IMPLEMENTED:
					throw new UnsupportedOperationException(JDIMessages.VirtualMachineImpl_Hierarchy_change_not_implemented_3); 
				case JdwpReplyPacket.DELETE_METHOD_NOT_IMPLEMENTED:
					throw new UnsupportedOperationException(JDIMessages.VirtualMachineImpl_Delete_method_not_implemented_4); 
				case JdwpReplyPacket.CLASS_MODIFIERS_CHANGE_NOT_IMPLEMENTED:
					throw new UnsupportedOperationException(JDIMessages.VirtualMachineImpl_Class_modifiers_change_not_implemented_5); 
				case JdwpReplyPacket.METHOD_MODIFIERS_CHANGE_NOT_IMPLEMENTED:
					throw new UnsupportedOperationException(JDIMessages.VirtualMachineImpl_Method_modifiers_change_not_implemented_6); 
				default:
					defaultReplyErrorHandler(reply.errorCode());
			}
		} catch (IOException ioe) {
			defaultIOExceptionHandler(ioe);
			return;
		} finally {
			handledJdwpRequest();
		}
	}

	/*
	 * @see VirtualMachine#canRedefineClasses()
	 */
	public boolean canRedefineClasses() {
		getCapabilities();
		return fCanRedefineClasses;
	}

	/*
	 * @see VirtualMachine#canUseInstanceFilters()
	 */
	public boolean canUseInstanceFilters() {
		getCapabilities();
		return fCanUseInstanceFilters;
	}

	/*
	 * @see VirtualMachine#canAddMethod()
	 */
	public boolean canAddMethod() {
		getCapabilities();
		return fCanAddMethod;
	}

	/*
	 * @see VirtualMachine#canUnrestrictedlyRedefineClasses()
	 */
	public boolean canUnrestrictedlyRedefineClasses() {
		getCapabilities();
		return fCanUnrestrictedlyRedefineClasses;
	}

	/*
	 * @see VirtualMachine#canPopFrames()
	 */
	public boolean canPopFrames() {
		getCapabilities();
		return fCanPopFrames;
	}

	/*
	 * @see VirtualMachine#canGetSourceDebugExtension()
	 */
	public boolean canGetSourceDebugExtension() {
		getCapabilities();
		return fCanGetSourceDebugExtension;
	}

	/*
	 * @see VirtualMachine#canRequestVMDeathEvent()
	 */
	public boolean canRequestVMDeathEvent() {
		getCapabilities();
		return fCanRequestVMDeathEvent;
	}
	
	public boolean canSetDefaultStratum() {
		getCapabilities();
		return fCanSetDefaultStratum;
	}

	/*
	 * @see VirtualMachine#setDefaultStratum(String)
	 */
	public void setDefaultStratum(String stratum) {
		fDefaultStratum= stratum;
		
		if (!canSetDefaultStratum()) {
			// TODO: how to inform the user that the VM doesn't manage setDefaultStartum ?
			return;
		}
		if (stratum == null) {
			stratum= ""; //$NON-NLS-1$
		}
		initJdwpRequest();
		try {
			ByteArrayOutputStream outBytes = new ByteArrayOutputStream();
			DataOutputStream outData = new DataOutputStream(outBytes);
			writeString(stratum, "stratum ID", outData); //$NON-NLS-1$
	
			JdwpReplyPacket replyPacket = requestVM(JdwpCommandPacket.VM_SET_DEFAULT_STRATUM, outBytes);
			defaultReplyErrorHandler(replyPacket.errorCode());
			
		} catch (IOException e) {
			defaultIOExceptionHandler(e);
		} finally {
			handledJdwpRequest();
		}
	}
	
	/*
	 * @see VirtualMachine#getDefaultStratum()
	 */
	public String getDefaultStratum() {
		return fDefaultStratum;
	}
	
	/**
	 * Returns whether this VM is disconnected.
	 * 
	 * @return whether this VM is disconnected
	 */
	public boolean isDisconnected() {
		return fIsDisconnected;
	}

	/**
	 * Sets whether this VM is disconnected.
	 * 
	 * @param disconected whether this VM is disconnected
	 */
	public synchronized void setDisconnected(boolean disconnected) {
		fIsDisconnected = disconnected;
	}
	
	/**
	 * Return the boolean type for this VM.
	 */
	protected BooleanTypeImpl getBooleanType() {
		if (fBooleanType == null) {
			fBooleanType= new BooleanTypeImpl(this);
		}
		return fBooleanType;
	}

	/**
	 * Return the byte type for this VM.
	 */
	protected ByteTypeImpl getByteType() {
		if (fByteType == null) {
			fByteType= new ByteTypeImpl(this);
		}
		return fByteType;
	}

	/**
	 * Return the char type for this VM.
	 */
	protected CharTypeImpl getCharType() {
		if (fCharType == null) {
			fCharType= new CharTypeImpl(this);
		}
		return fCharType;
	}

	/**
	 * Return the double type for this VM.
	 */
	protected DoubleTypeImpl getDoubleType() {
		if (fDoubleType == null) {
			fDoubleType= new DoubleTypeImpl(this);
		}
		return fDoubleType;
	}

	/**
	 * Return the float type for this VM.
	 */
	protected FloatTypeImpl getFloatType() {
		if (fFloatType == null) {
			fFloatType= new FloatTypeImpl(this);
		}
		return fFloatType;
	}

	/**
	 * Return the integer type for this VM.
	 */
	protected IntegerTypeImpl getIntegerType() {
		if (fIntegerType == null) {
			fIntegerType= new IntegerTypeImpl(this);
		}
		return fIntegerType;
	}

	/**
	 * Return the long type for this VM.
	 */
	protected LongTypeImpl getLongType() {
		if (fLongType == null) {
			fLongType= new LongTypeImpl(this);
		}
		return fLongType;
	}

	/**
	 * Return the short type for this VM.
	 */
	protected ShortTypeImpl getShortType() {
		if (fShortType == null) {
			fShortType= new ShortTypeImpl(this);
		}
		return fShortType;
	}
	
	/*
	 *  (non-Javadoc)
	 * @see com.sun.jdi.VirtualMachine#canBeModified()
	 */
	public boolean canBeModified() {
		return true;
	}

}