public abstract class StateManager
{
public boolean activate ();
public boolean deactivate (boolean commit);

public Uid get_uid (); // object’s identifier.

// methods to be provided by a derived class

public boolean restore_state (InputObjectState os);
public boolean save_state (OutputObjectState os);

protected StateManager ();
protected StateManager (Uid id);
};

public boolean save_state(OutputObjectState o)
{
    if (!super.save_state(o))
	return false;
      
    try
	{
	    o.packInt(A);
	    o.packInt(B);
	    o.packInt(C));
}
catch (Exception e)
    {
	return false;
    }
      
return true;
}                      

public class Example extends LockManager
{
    public boolean foobar ()
    {
	AtomicAction A = new AtomicAction;
	boolean result = false;
      
	A.begin();
      
	if (setlock(new Lock(LockMode.WRITE), 0) == Lock.GRANTED)
	    {
		/*
		 * Do some work, and TXOJ will
		 * guarantee ACID properties.
		 */
      
		// automatically aborts if fails
      
		if (A.commit() == AtomicAction.COMMITTED)
		    {
			result = true;
		    }
	    }
	else
	    A.rollback();
      
	return result;
    }
}

{
      . . .
      O1 objct1 = new objct1(Name-A);/* (i) bind to "old" persistent object A */
      O2 objct2 = new objct2();	 /* create a "new" persistent object */
      OTS.current().begin();		 /* (ii) start of atomic action */
      
      objct1.op(...);		      /* (iii) object activation and invocations */
      objct2.op(...);
      . . .
      OTS.current().commit(true); 	/* (iv) tx commits & objects deactivated */
      } 					/* (v) */

StateManager		// Basic naming, persistence and recovery control
LockManager		// Basic two-phase locking concurrency control service
User-Defined Classes
Lock			// Standard lock type for multiple readers/single writer
User-Defined Lock Classes
AbstractRecord		// Important utility class, similar to Resource
RecoveryRecord	            // handles object recovery
LockRecord		// handles object locking
RecordList		// Intentions list
other management record types
AtomicAction		// Implements transaction control abstraction
TopLevelTransaction
Input/OutputBuffer // Architecture neutral representation of an objects’ state
Input/OutputObjectState	// Convenient interface to Buffer
ObjectStore			// Interface to the object storage services
      

public class OutputBuffer
{
    public OutputBuffer ();

    public final synchronized boolean valid ();
    public synchronized byte[] buffer();
    public synchronized int length ();

    /* pack operations for standard Java types */

    public synchronized void packByte (byte b) throws IOException;
    public synchronized void packBytes (byte[] b) throws IOException;
    public synchronized void packBoolean (boolean b) throws IOException;
    public synchronized void packChar (char c) throws IOException;
    public synchronized void packShort (short s) throws IOException;
    public synchronized void packInt (int i) throws IOException;
    public synchronized void packLong (long l) throws IOException;
    public synchronized void packFloat (float f) throws IOException;
    public synchronized void packDouble (double d) throws IOException;
    public synchronized void packString (String s) throws IOException;
};

public class InputBuffer
{
    public InputBuffer ();

    public final synchronized boolean valid ();
    public synchronized byte[] buffer();
    public synchronized int length ();

    /* unpack operations for standard Java types */

    public synchronized byte unpackByte () throws IOException;
    public synchronized byte[] unpackBytes () throws IOException;
    public synchronized boolean unpackBoolean () throws IOException;
    public synchronized char unpackChar () throws IOException;
    public synchronized short unpackShort () throws IOException;
    public synchronized int unpackInt () throws IOException;
    public synchronized long unpackLong () throws IOException;
    public synchronized float unpackFloat () throws IOException;
    public synchronized double unpackDouble () throws IOException;
    public synchronized String unpackString () throws IOException;
};

class OutputObjectState extends OutputBuffer
{
    public OutputObjectState (Uid newUid, String typeName);

    public boolean notempty ();
    public int size ();
    public Uidpublic class InputBuffer
    {
	public InputBuffer ();

	public final synchronized boolean valid ();
	public synchronized byte[] buffer();
	public synchronized int length ();

	/* unpack operations for standard Java types */

	public synchronized byte unpackByte () throws IOException;
	public synchronized byte[] unpackBytes () throws IOException;
	public synchronized boolean unpackBoolean () throws IOException;
	public synchronized char unpackChar () throws IOException;
	public synchronized short unpackShort () throws IOException;
	public synchronized int unpackInt () throws IOException;
	public synchronized long unpackLong () throws IOException;
	public synchronized float unpackFloat () throws IOException;
	public synchronized double unpackDouble () throws IOException;
	public synchronized String unpackString () throws IOException;
    };

class InputObjectState extends InputBuffer
{
    public InputObjectState (Uid newUid, String typeName, byte[] b);

    public boolean notempty ();
    public int size ();
    public Uid stateUid ();
    public String type ();
};

public boolean save_state ( OutputObjectState os, int ObjectType )
{
    if (!super.save_state(os, ObjectType))
	return false;
      
    try
	{
	    os.packInt(A);
	    os.packString(B);
	    os.packFloat(C);
      
	    return true;
	}
    catch (IOException e)
	{
	    return false;
	}
}

{
    ObjectName attr = new ObjectName(“SNS:myObjectName”);
      
    attr.setLongAttribute(ArjunaNames.StateManager_objectModel(),
			  ObjectModel.SINGLE);
      
    AtomicObject obj = new AtomicObject(ObjectType.ANDPERSISTENT, attr);
}

public class Array extends StateManager
{
    public Array ();
    public Array (Uid objUid);
    public void finalize ( super.terminate(); };
      
    /* Class specific operations. */
      
    public boolean set (int index, int value);
    public int get (int index);
      
    /* State management specific operations. */
      
    public boolean save_state (OutputObjectState os, int ObjectType);
    public boolean restore_state (InputObjectState os, int ObjectType);
    public String type ();
      
    public static final int ARRAY_SIZE = 10;
      
    private int[] elements = new int[ARRAY_SIZE];
    private int highestIndex;
};

/* Ignore ObjectType parameter for simplicity */

public boolean save_state (OutputObjectState os, int ObjectType)
{
    if (!super.save_state(os, ObjectType))
	return false;
      
    try
	{    
	    packInt(highestIndex);

	    /*
	     * Traverse array state that we wish to save. Only save active elements
	     */

	    for (int i = 0; i <= highestIndex; i++)
		os.packInt(elements[i]);
      
	    return true;
	}
    catch (IOException e)
	{
	    return false;
	}
}
      
public boolean restore_state (InputObjectState os, int ObjectType)
{
    if (!super.restore_state(os, ObjectType))
	return false;
      
    try
	{
	    int i = 0;
      
	    highestIndex = os.unpackInt();
      
	    while (i < ARRAY_SIZE)
		{
		    if (i <= highestIndex)
			elements[i] =  os.unpackInt();
		    else
			elements[i] = 0;
		    i++;
		}
      
	    return true;
	}
    catch (IOException e)
	{
	    return false;
	}
}
      
public String type ()
{
    return '/StateManager/Array';
}

public class LockResult
{
    public static final int GRANTED;
    public static final int REFUSED;
    public static final int RELEASED;
};

public class ConflictType
{
    public static final int CONFLICT;
    public static final int COMPATIBLE;
    public static final int PRESENT;
};

public abstract class LockManager extends StateManager
{
    public static final int defaultTimeout;
    public static final int defaultRetry;
    public static final int waitTotalTimeout;

    public synchronized int setlock (Lock l);
    public synchronized int setlock (Lock l, int retry);
    public synchronized int setlock (Lock l, int retry, int sleepTime);
    public synchronized boolean releaselock (Uid uid);

    /* abstract methods inherited from StateManager */

    public boolean restore_state (InputObjectState os, int ObjectType);
    public boolean save_state (OutputObjectState os, int ObjectType);
    public String type ();

    protected LockManager ();
    protected LockManager (int ObjectType, ObjectName attr);
    protected LockManager (Uid storeUid);
    protected LockManager (Uid storeUid, int ObjectType, ObjectName attr);
    . . .
};

res = setlock(new Lock(WRITE), 10); 
// Attempts to set a write
// lock 11 times (10 retries)
// before giving up.
      
res = setlock(new Lock(READ), 0); 
// Attempts to set a read lock
// 1 time (no retries) before
// giving up.
      
res = setlock(new Lock(WRITE); 
// Attempts to set a write lock
// 101 times (default of 100
// retries) before giving up.

public class TxStats
{

    // Returns the number of transactions (top-level and nested)
    // created so far.

    public static int numberOfTransactions ();

    // Returns the number of nested (sub) transactions created so far.

    public static int numberOfNestedTransactions ();

    // Returns the number of transactions which have terminated with
    // heuristic outcomes.

    public static int numberOfHeuristics ();

    // Returns the number of committed transactions.

    public static int numberOfCommittedTransactions ();

    // Returns the number of transactions which have rolled back.

    public static int numberOfAbortedTransactions ();

}

try
    {
	boolean success = false;
	AtomicAction A = new AtomicAction();
	OnePhase opRes = new OnePhase();  // used OnePhase interface
      
	System.err.println("Starting top-level action.");
      
	A.begin();
	A.add(new LastResourceRecord(opRes));
	A.add(new ShutdownRecord(ShutdownRecord.FAIL_IN_PREPARE));
      
	A.commit();
    }

public boolean set (int index, int value)
{
    boolean result = false;
    AtomicAction A = new AtomicAction();

    A.begin();

    // We need to set a WRITE lock as we want to modify the state.

    if (setlock(new Lock(LockMode.WRITE), 0) == LockResult.GRANTED)
	{
	    elements[index] = value;
	    if ((value > 0) && (index > highestIndex))
		highestIndex = index;
	    A.commit(true);
	    result = true;
	}
    else
	A.rollback();

    return result;
}

public int get (int index)  // assume -1 means error
{
    AtomicAction A = new AtomicAction();

    A.begin();

    // We only need a READ lock as the state is unchanged.

    if (setlock(new Lock(LockMode.READ), 0) == LockResult.GRANTED)
	{
	    A.commit(true);

	    return elements[index];
	}
    else
	A.rollback();

    return -1;
}

AtomicAction A = new AtomicAction();
Object obj1;
Object obj2;

obj1 = new Object();			// create new object
obj2 = new Object("old");		// existing object

A.begin(0);
obj2.remember(obj1.get_uid());	// obj2 now contains reference to obj1
A.commit(true);				// obj2 saved but obj1 is not

public class Test
{
    public Test (String s);
    ...
	private String s1;
    private String s2;
};

public Test (String s)
{
    s1 = s;
    s2 = s;
}

	  public class TransactionalQueue extends LockManager
	  {
	  public TransactionalQueue (Uid uid);
	  public TransactionalQueue ();
	  public void finalize ();
	  
	  public void enqueue (int v) throws OverFlow, UnderFlow,
	  QueueError, Conflict;
	  public int dequeue  () throws OverFlow, UnderFlow,
	  QueueError, Conflict;
	  
	  public int queueSize ();
	  public int inspectValue (int i) throws OverFlow,
	  UnderFlow, QueueError, Conflict;
	  public void setValue (int i, int v) throws OverFlow,
	  UnderFlow, QueueError, Conflict;
	  
	  public boolean save_state (OutputObjectState os, int ObjectType);
	  public boolean restore_state (InputObjectState os, int ObjectType);
	  public String type ();
	  
	  public static final int QUEUE_SIZE = 40; // maximum size of the queue
	  
	  private int[QUEUE_SIZE] elements;
	  private int numberOfElements;
	  };

	  public TransactionalQueue (Uid u)
	  {
	  super(u);
	  
	  numberOfElements = 0;
	  }

	  public TransactionalQueue ()
	  {
	  super(ObjectType.ANDPERSISTENT);
	  
	  numberOfElements = 0;
	  
	  try
	  {
	  AtomicAction A = new AtomicAction();
	  
	  A.begin(0);	// Try to start atomic action
	  
	  // Try to set lock
	  
	  if (setlock(new Lock(LockMode.WRITE), 0) == LockResult.GRANTED)
	  {
	  A.commit(true);	// Commit
	  }
	  else 	// Lock refused so abort the atomic action
	  A.rollback();
	  }
	  catch (Exception e)
	  {
	  System.err.println(“Object construction error: “+e);
	  System.exit(1);
	  }
	  }

	  public void finalize ()
	  {
	  super.terminate();
	  }

	  public boolean save_state (OutputObjectState os, int ObjectType)
	  {
	  if (!super.save_state(os, ObjectType))
	  return false;
	  
	  try
	  {
	  os.packInt(numberOfElements);
	  
	  if (numberOfElements > 0)
	  {
	  for (int i = 0; i < numberOfElements; i++)
	  os.packInt(elements[i]);
	  }
	  
	  return true;
	  }
	  catch (IOException e)
	  {
	  return false;
	  }
	  }

	  public boolean restore_state (InputObjectState os, int ObjectType)
	  {
	  if (!super.restore_state(os, ObjectType))
	  return false;
	  
	  try
	  {
	  numberOfElements = os.unpackInt();
	  
	  if (numberOfElements > 0)
	  {
	  for (int i = 0; i < numberOfElements; i++)
	  elements[i] = os.unpackInt();
	  }
	  
	  return true;
	  }
	  catch (IOException e)
	  {
	  return false;
	  }
	  }

	  public String type ()
	  {
	  return "/StateManager/LockManager/TransactionalQueue";
	  }

	  public void enqueue (int v) throws OverFlow, UnderFlow, QueueError
	  {
	  AtomicAction A = new AtomicAction();
	  boolean res = false;
	  
	  try
	  {
	  A.begin(0);
	  
	  if (setlock(new Lock(LockMode.WRITE), 0) == LockResult.GRANTED)
	  {
	  if (numberOfElements < QUEUE_SIZE)
	  {
	  elements[numberOfElements] = v;
	  numberOfElements++;
	  res = true;
	  }
	  else
	  {
	  A.rollback();
	  throw new UnderFlow();
	  }
	  }
	  
	  if (res)
	  A.commit(true);
	  else
	  {
	  A.rollback();
	  throw new Conflict();
	  }
	  }
	  catch (Exception e1)
	  {
	  throw new QueueError();
	  }
	  }

	  public static void main (String[] args)
	  {
	  TransactionalQueue myQueue = new TransactionalQueue();

	  AtomicAction A = new AtomicAction();
	  int size = 0;
	  
	  try
	  {
	  A.begin(0);
	  s
	  try
	  {
	  size = queue.queueSize();
	  }
	  catch (Exception e)
	  {
	  }
	  
	  if (size >= 0)
	  {
	  A.commit(true);
	  
	  System.out.println(“Size of queue: “+size);
	  }
	  else
	  A.rollback();
	  }
	  catch (Exception e)
	  {
	  System.err.println(“Caught unexpected exception!”);
	  }

<!-- Activation Service portType Declaration --> 
<wsdl:portType name="ActivationCoordinatorPortType"> 
  <wsdl:operation name="CreateCoordinationContext"> 
    <wsdl:input message="wscoor:CreateCoordinationContext"/> 
    <wsdl:output message="wscoor:CreateCoordinationContextResponse"/> 
  </wsdl:operation> 
</wsdl:portType> 

<!-- Registration Service portType Declaration --> 
<wsdl:portType name="RegistrationCoordinatorPortType"> 
  <wsdl:operation name="Register"> 
    <wsdl:input message="wscoor:Register"/> 
    <wsdl:output message="wscoor:RegisterResponse"/> 
  </wsdl:operation> 
</wsdl:portType> 

public Vote prepare () throws WrongStateException, SystemException
{
  // Some participant logic here

  if(/* some condition based on the outcome of the business logic */)
  {
    // Vote to confirm
    return new com.arjuna.wst.Prepared();
  }
  else if(/*another condition based on the outcome of the business logic*/)
  {
    // Resign
    return new com.arjuna.wst.ReadOnly();
  }
  else
  {
    // Vote to cancel
    return new com.arjuna.wst.Aborted();
  }
}