/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.resource.connectionmanager;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Iterator;
import java.util.Map;

import javax.management.Notification;
import javax.management.NotificationFilter;
import javax.management.NotificationListener;
import javax.management.ObjectName;
import javax.resource.ResourceException;
import javax.resource.spi.ConnectionRequestInfo;
import javax.resource.spi.ManagedConnectionFactory;
import javax.security.auth.Subject;
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;

import org.jboss.deployment.DeploymentException;
import org.jboss.logging.Logger;
import org.jboss.mx.util.JMXExceptionDecoder;
import org.jboss.resource.JBossResourceException;
import org.jboss.resource.connectionmanager.InternalManagedConnectionPool.PoolParams;
import org.jboss.system.ServiceMBeanSupport;
import org.jboss.tm.TransactionLocal;

import EDU.oswego.cs.dl.util.concurrent.ConcurrentReaderHashMap;

/**
 * The JBossManagedConnectionPool mbean configures and supplies pooling of
 * JBossConnectionEventListeners to the BaseConnectionManager2 mbean.<p>
 *   
 * It may be replaced by any mbean with a readable ManagedConnectionPool attribute
 * of type ManagedConnectionPool.  Normal pooling parameters are supplied,
 * and the criteria to distinguish ManagedConnections is set in the Criteria attribute.
 *
 * @author <a href="mailto:d_jencks@users.sourceforge.net">David Jencks</a>
 * @author <a href="mailto:adrian@jboss.org">Adrian Brock</a>
 * @version $Revision$
 */
public class JBossManagedConnectionPool extends ServiceMBeanSupport 
   implements JBossManagedConnectionPoolMBean, NotificationListener
{
   /** The managed connection factory name */
   private ObjectName managedConnectionFactoryName;

   /** The pooling criteria */
   private String criteria;

   /** The pooling strategy */
   private ManagedConnectionPool poolingStrategy;

   /** The pooling parameters */
   private final InternalManagedConnectionPool.PoolParams poolParams = new InternalManagedConnectionPool.PoolParams();

   /** Whether to use separate pools for transactional and non-transaction use */
   private boolean noTxSeparatePools;

   public JBossManagedConnectionPool()
   {
   }

   public ManagedConnectionPool getManagedConnectionPool()
   {
      return poolingStrategy;
   }

   public ObjectName getManagedConnectionFactoryName()
   {
      return managedConnectionFactoryName;
   }

   public void setManagedConnectionFactoryName(ObjectName newManagedConnectionFactoryName)
   {
      this.managedConnectionFactoryName = newManagedConnectionFactoryName;
   }

   public long getAvailableConnectionCount()
   {
      return (poolingStrategy == null) ? 0 : poolingStrategy.getAvailableConnectionCount();
   }

   public long getMaxConnectionsInUseCount()
   {
      return (poolingStrategy == null) ? 0 : poolingStrategy.getMaxConnectionsInUseCount();
   }

   public long getInUseConnectionCount ()
   {
      return (poolingStrategy == null) ? 0 : poolingStrategy.getInUseConnectionCount();
   }

   public int getMinSize()
   {
      return poolParams.minSize;
   }

   public void setMinSize(int newMinSize)
   {
      poolParams.minSize = newMinSize;
   }

   public int getMaxSize()
   {
      return poolParams.maxSize;
   }

   public void setMaxSize(int newMaxSize)
   {
      poolParams.maxSize = newMaxSize;
   }

   public int getBlockingTimeoutMillis()
   {
      return poolParams.blockingTimeout;
   }

   public void setBlockingTimeoutMillis(int newBlockingTimeout)
   {
      poolParams.blockingTimeout = newBlockingTimeout;
   }

   public long getIdleTimeoutMinutes()
   {
      return poolParams.idleTimeout / (1000 * 60);
   }

   public void setIdleTimeoutMinutes(long newIdleTimeoutMinutes)
   {
      poolParams.idleTimeout = newIdleTimeoutMinutes * 1000 * 60;
   }

   /**
    * Get the IdleTimeout value.
    *
    * @return the IdleTimeout value.
    */
   public long getIdleTimeout()
   {
      return poolParams.idleTimeout;
   }

   /**
    * Set the IdleTimeout value.
    *
    * @param newIdleTimeout The new IdleTimeout value.
    */
   public void setIdleTimeout(long newIdleTimeout)
   {
      poolParams.idleTimeout = newIdleTimeout;
   }

   public String getCriteria()
   {
      return criteria;
   }

   public void setCriteria(String newCriteria)
   {
      this.criteria = newCriteria;
   }

   public boolean getNoTxSeparatePools()
   {
      return noTxSeparatePools;
   }

   public void setNoTxSeparatePools(boolean value)
   {
      this.noTxSeparatePools = value;
   }

   public void flush()
   {
      if (poolingStrategy == null)
         throw new IllegalStateException("The connection pool is not started");
      poolingStrategy.flush();
   }

   public int getConnectionCount()
   {
      return (poolingStrategy == null)? 0: poolingStrategy.getConnectionCount();
   }

   public int getConnectionCreatedCount()
   {
      return (poolingStrategy == null)? 0: poolingStrategy.getConnectionCreatedCount();
   }

   public int getConnectionDestroyedCount()
   {
      return (poolingStrategy == null)? 0: poolingStrategy.getConnectionDestroyedCount();
   }

   public String getName()
   {
      return "JBossManagedConnectionPool";
   }

   protected void startService() throws Exception
   {
      ManagedConnectionFactory mcf = null;
      if (managedConnectionFactoryName == null)
         throw new DeploymentException("ManagedConnectionFactory not set!");

      try
      {
         //We are getting the actual mcf instance itself.  This will require
         //some work if the mcf is an xmbean of itself.
         mcf = (ManagedConnectionFactory)server.getAttribute(managedConnectionFactoryName, "McfInstance");
      }
      catch (Exception e)
      {
         JMXExceptionDecoder.rethrow(e);
      }
      getServer().addNotificationListener
      (
         managedConnectionFactoryName,
         this,
         new NotificationFilter()
         {
            private static final long serialVersionUID = -9211456539783257343L;

            public boolean isNotificationEnabled(Notification n)
            {
               return RARDeployment.MCF_ATTRIBUTE_CHANGED_NOTIFICATION.equals(n.getType())
                      && managedConnectionFactoryName.equals(n.getSource());
            }
         },
         null
      );

      if ("ByContainerAndApplication".equals(criteria))
         poolingStrategy = new PoolBySubjectAndCri(mcf, poolParams, noTxSeparatePools, log);
      else if ("ByContainer".equals(criteria))
         poolingStrategy = new PoolBySubject(mcf, poolParams, noTxSeparatePools, log);
      else if ("ByApplication".equals(criteria))
         poolingStrategy = new PoolByCri(mcf, poolParams, noTxSeparatePools, log);
      else if ("ByNothing".equals(criteria))
         poolingStrategy = new OnePool(mcf, poolParams, noTxSeparatePools, log);
      else
         throw new DeploymentException("Unknown pooling criteria: " + criteria);
   }

   protected void stopService() throws Exception
   {
      if (poolingStrategy != null)
         poolingStrategy.shutdown();
      getServer().removeNotificationListener(managedConnectionFactoryName, this);
      poolingStrategy = null;
   }

   public void handleNotification(Notification notification,
                                  Object handback)
   {
      flush();
   }

   public static class SubPoolContext
   {
      /** The subpool */
      private InternalManagedConnectionPool subPool;
      
      /** The track by transaction transaction local */
      private TransactionLocal trackByTx;

      /**
       * Create a new SubPoolContext.
       * 
       * @param tm the transaction manager
       * @param mcf the managed connection factory
       * @param clf the connection listener factory
       * @param subject the subject
       * @param cri the connection request info
       * @param poolParams the pool parameters
       * @param log the log
       */
      public SubPoolContext(TransactionManager tm, ManagedConnectionFactory mcf, ConnectionListenerFactory clf, Subject subject,
            ConnectionRequestInfo cri, PoolParams poolParams, Logger log)
      {
         subPool = new InternalManagedConnectionPool(mcf, clf, subject, cri, poolParams, log);
         if (tm != null)
            trackByTx = new TransactionLocal(tm);
      }
      
      /**
       * Get the sub pool
       * 
       * @return the sub pool
       */
      public InternalManagedConnectionPool getSubPool()
      {
         return subPool;
      }
      
      /**
       * Get the track by transaction
       * 
       * @return the transaction local
       */
      public TransactionLocal getTrackByTx()
      {
         return trackByTx;
      }
      
      /**
       * Initialize the subpool context
       */
      public void initialize()
      {
         subPool.initialize();
      }
   }
   
   /**
    * The base pool implementation
    */
   public abstract static class BasePool implements ManagedConnectionPool
   {
      /** The subpools */
      private final Map subPools = new ConcurrentReaderHashMap();

      /** The managed connection factory */
      private final ManagedConnectionFactory mcf;
      
      /** The connection listener factory */
      private ConnectionListenerFactory clf;

      /** The pool parameters */
      private final InternalManagedConnectionPool.PoolParams poolParams;

      /** Whether to use separate pools for transactional and non-transaction use */
      private boolean noTxSeparatePools;

      /** The logger */
      private final Logger log;

      /** Is trace enabled */
      private boolean traceEnabled = false;

      /**
       * Create a new base pool
       * 
       * @param mcf the managed connection factory
       * @param poolParams the pooling parameters
       * @param log the log
       */
      public BasePool(final ManagedConnectionFactory mcf, final InternalManagedConnectionPool.PoolParams poolParams,
                      final boolean noTxSeparatePools, final Logger log)
      {
         this.mcf = mcf;
         this.poolParams = poolParams;
         this.noTxSeparatePools = noTxSeparatePools;
         this.log = log;
         this.traceEnabled = log.isTraceEnabled();
      }

      /**
       * Retrieve the key for this request
       * 
       * @param subject the subject 
       * @param cri the connection request information
       * @return the key
       * @throws ResourceException for any error
       */
      protected abstract Object getKey(Subject subject, ConnectionRequestInfo cri, boolean separateNoTx) throws ResourceException;

      public ManagedConnectionFactory getManagedConnectionFactory()
      {
         return mcf;
      }

      public void setConnectionListenerFactory(ConnectionListenerFactory clf)
      {
         this.clf = clf;
      }

      public ConnectionListener getConnection(Transaction trackByTransaction, Subject subject, ConnectionRequestInfo cri)
         throws ResourceException
      {
         // Determine the pool key for this request
         boolean separateNoTx = false;
         if (noTxSeparatePools)
            separateNoTx = clf.isTransactional();
         Object key = getKey(subject, cri, separateNoTx);
         SubPoolContext subPool = getSubPool(key, subject, cri);
         
         InternalManagedConnectionPool mcp = subPool.getSubPool();
         
         // Are we doing track by connection?
         TransactionLocal trackByTx = subPool.getTrackByTx();

         // Simple case
         if (trackByTransaction == null || trackByTx == null)
         {
            ConnectionListener cl = mcp.getConnection(subject, cri);
            if (traceEnabled)
               dump("Got connection from pool " + cl);
            return cl;
         }

         // Track by transaction
         try
         {
            trackByTx.lock(trackByTransaction);
         }
         catch (Throwable t)
         {
            JBossResourceException.rethrowAsResourceException("Unable to get connection from the pool for tx=" + trackByTransaction, t);
         }
         try
         {
            // Already got one
            ConnectionListener cl = (ConnectionListener) trackByTx.get(trackByTransaction);
            if (cl != null)
            {
               if (traceEnabled)
                  dump("Previous connection tracked by transaction " + cl + " tx=" + trackByTransaction);
               return cl;
            }
         }
         finally
         {
            trackByTx.unlock(trackByTransaction);
         }

         // Need a new one for this transaction
         // This must be done outside the tx local lock, otherwise
         // the tx timeout won't work and get connection can do a lot of other work
         // with many opportunities for deadlocks.
         // Instead we do a double check after we got the transaction to see
         // whether another thread beat us to the punch.
         ConnectionListener cl = mcp.getConnection(subject, cri);
         if (traceEnabled)
            dump("Got connection from pool tracked by transaction " + cl + " tx=" + trackByTransaction);
         
         // Relock and check/set status
         try
         {
            trackByTx.lock(trackByTransaction);
         }
         catch (Throwable t)
         {
            mcp.returnConnection(cl, false);
            if (traceEnabled)
               dump("Had to return connection tracked by transaction " + cl + " tx=" + trackByTransaction + " error=" + t.getMessage());
            JBossResourceException.rethrowAsResourceException("Unable to get connection from the pool for tx=" + trackByTransaction, t);
         }
         try
         {
            // Check we weren't racing with another transaction
            ConnectionListener other = (ConnectionListener) trackByTx.get(trackByTransaction);
            if (other != null)
            {
               mcp.returnConnection(cl, false);
               if (traceEnabled)
                  dump("Another thread already got a connection tracked by transaction " + other + " tx=" + trackByTransaction);
               return other;
            }
            
            // This is the connection for this transaction
            cl.setTrackByTx(true);
            trackByTx.set(cl);
            if (traceEnabled)
               dump("Using connection from pool tracked by transaction " + cl + " tx=" + trackByTransaction);
            return cl;
         }
         finally
         {
            trackByTx.unlock(trackByTransaction);
         }
      }

      public void returnConnection(ConnectionListener cl, boolean kill) throws ResourceException
      {
         cl.setTrackByTx(false);
         InternalManagedConnectionPool mcp = (InternalManagedConnectionPool) cl.getContext();
         mcp.returnConnection(cl, kill);
         if (traceEnabled)
            dump("Returning connection to pool " + cl);
      }
      
      /**
       * Return the inuse count
       * 
       * @return the count
       */
      public int getInUseConnectionCount()
      {
         int count = 0;
         synchronized (subPools)
         {
            for (Iterator i = subPools.values().iterator(); i.hasNext(); )
            {
               SubPoolContext subPool = (SubPoolContext) i.next();
               count += subPool.getSubPool().getConnectionInUseCount();
            }
         }
         return count;
      }
      
      public int getConnectionCount()
      {
         int count = 0;
         synchronized (subPools)
         {
            for (Iterator i = subPools.values().iterator(); i.hasNext(); )
            {
               SubPoolContext subPool = (SubPoolContext) i.next();
               count += subPool.getSubPool().getConnectionCount();
            }
         }
         return count;
      }

      public int getConnectionCreatedCount()
      {
         int count = 0;
         synchronized (subPools)
         {
            for (Iterator i = subPools.values().iterator(); i.hasNext(); )
            {
               SubPoolContext subPool = (SubPoolContext) i.next();
               count += subPool.getSubPool().getConnectionCreatedCount();
            }
         }
         return count;
      }

      public int getConnectionDestroyedCount()
      {
         int count = 0;
         synchronized (subPools)
         {
            for (Iterator i = subPools.values().iterator(); i.hasNext(); )
            {
               SubPoolContext subPool = (SubPoolContext) i.next();
               count += subPool.getSubPool().getConnectionDestroyedCount();
            }
         }
         return count;
      }

      public long getAvailableConnectionCount()
      {
         long count = 0;
         synchronized (subPools)
         {
            if (subPools.size() == 0)
               return poolParams.maxSize;
            for (Iterator i = subPools.values().iterator(); i.hasNext(); )
            {
               SubPoolContext subPool = (SubPoolContext) i.next();
               count += subPool.getSubPool().getAvailableConnections();
            }
         }
         return count;
      }

      public int getMaxConnectionsInUseCount()
      {
         int count = 0;
         synchronized (subPools)
         {
            for (Iterator i = subPools.values().iterator(); i.hasNext(); )
            {
               SubPoolContext subPool = (SubPoolContext) i.next();
               count += subPool.getSubPool().getMaxConnectionsInUseCount();
            }
         }
         return count;
      }
      
      public void shutdown()
      {
         synchronized (subPools)
         {
            for (Iterator i = subPools.values().iterator(); i.hasNext(); )
            {
               SubPoolContext subPool = (SubPoolContext) i.next();
               subPool.getSubPool().shutdown();
            }
            subPools.clear();
         }
      }

      public void flush()
      {
         synchronized (subPools)
         {
            for (Iterator i = subPools.values().iterator(); i.hasNext(); )
            {
               SubPoolContext subPool = (SubPoolContext) i.next();
               subPool.getSubPool().shutdown();
            }
            subPools.clear();
         }
      }

      /**
       * For testing
       */
      protected void shutdownWithoutClear()
      {
         synchronized (subPools)
         {
            for (Iterator i = subPools.values().iterator(); i.hasNext(); )
            {
               SubPoolContext subPool = (SubPoolContext) i.next();
               subPool.getSubPool().shutdown();
            }
         }
      }
      
      /**
       * Get any transaction manager associated with the pool
       * 
       * @return the transaction manager
       */
      protected TransactionManager getTransactionManager()
      {
         if (clf != null)
            return clf.getTransactionManagerInstance();
         else
            return null;
      }

      /**
       * Determine the correct pool for this request,
       * creates a new one when necessary
       * 
       * @param key the key to the pool
       * @param subject the subject of the pool
       * @param cri the connection request info
       * @return the subpool context
       * @throws ResourceException for any error
       */
      private SubPoolContext getSubPool(Object key, Subject subject, ConnectionRequestInfo cri) throws ResourceException
      {
         SubPoolContext subPool = (SubPoolContext) subPools.get(key);
         if (subPool == null)
         {
            TransactionManager tm = getTransactionManager();
            subPool = new SubPoolContext(tm, mcf, clf, subject, cri, poolParams, log);
            synchronized (subPools)
            {
               if (subPools.containsKey(key))
                  subPool = (SubPoolContext) subPools.get(key);
               else
               {
                  subPool.initialize();
                  subPools.put(key, subPool);
               }
            }
         }
         return subPool;
      }

      /**
       * Dump the stats to the trace log
       * 
       * @param info some context
       */
      private void dump(String info)
      {
         if (traceEnabled)
         {
            StringBuffer toLog = new StringBuffer(100);
            toLog.append(info).append(" [InUse/Available/Max]: [");
            toLog.append(this.getInUseConnectionCount()).append("/");
            toLog.append(this.getAvailableConnectionCount()).append("/");
            toLog.append(this.poolParams.maxSize);
            toLog.append("]");;
            log.trace(toLog);
         }
      }
   }

   /**
    * Pooling by subject and connection request information
    */
   public static class PoolBySubjectAndCri
      extends BasePool
   {
      public PoolBySubjectAndCri(final ManagedConnectionFactory mcf,
                                 final InternalManagedConnectionPool.PoolParams poolParams,
                                 final boolean noTxSeparatePools, 
                                 final Logger log)
      {
         super(mcf, poolParams, noTxSeparatePools, log);
      }

      protected Object getKey(final Subject subject, final ConnectionRequestInfo cri, final boolean separateNoTx) throws ResourceException
      {
         return new SubjectCriKey(subject, cri, separateNoTx);
      }
   }

   /**
    * Pool by subject and criteria
    */
   private static class SubjectCriKey
   {
      /** Identifies no subject */
      private static final Subject NOSUBJECT = new Subject();
      
      /** Identifies no connection request information */
      private static final Object NOCRI = new Object();

      /** The subject */
      private final Subject subject;
      
      /** The connection request information */
      private final Object cri;
      
      /** The cached hashCode */
      private int hashCode = Integer.MAX_VALUE;

      /** Separate no tx */
      private boolean separateNoTx;

      SubjectCriKey(Subject subject, ConnectionRequestInfo cri, boolean separateNoTx)
      {
         this.subject = (subject == null)? NOSUBJECT:subject;
         this.cri = (cri == null)? NOCRI:cri;
         this.separateNoTx = separateNoTx;
      }

      public int hashCode()
      {
         if (hashCode == Integer.MAX_VALUE)
            hashCode = SubjectActions.hashCode(subject) ^ cri.hashCode();
         return hashCode;
      }

      public boolean equals(Object obj)
      {
         if (this == obj)
            return true;
         if (obj == null || (obj instanceof SubjectCriKey) == false)
            return false;
         SubjectCriKey other = (SubjectCriKey) obj;
         return SubjectActions.equals(subject, other.subject) 
            && cri.equals(other.cri)
            && separateNoTx == other.separateNoTx;
      }
   }

   /**
    * Pool by subject
    */
   public static class PoolBySubject
      extends BasePool
   {

      public PoolBySubject(final ManagedConnectionFactory mcf,
                           final InternalManagedConnectionPool.PoolParams poolParams,
                           final boolean noTxSeparatePools, 
                           final Logger log)
      {
         super(mcf, poolParams, noTxSeparatePools, log);
      }

      protected Object getKey(final Subject subject, final ConnectionRequestInfo cri, boolean separateNoTx)
      {
         return new SubjectKey(subject, separateNoTx);
      }
   }

   /**
    * Pool by subject
    */
   private static class SubjectKey
   {
      /** Identifies no subject */
      private static final Subject NOSUBJECT = new Subject();

      /** The subject */
      private final Subject subject;

      /** Separate no tx */
      private boolean separateNoTx;
      
      /** The cached hashCode */
      private int hashCode = Integer.MAX_VALUE;

      SubjectKey(Subject subject, boolean separateNoTx)
      {
         this.subject = (subject == null)? NOSUBJECT:subject;
         this.separateNoTx = separateNoTx;
      }

      public int hashCode()
      {
         if (hashCode == Integer.MAX_VALUE)
            hashCode = SubjectActions.hashCode(subject);
         return hashCode;
      }

      public boolean equals(Object obj)
      {
         if (this == obj)
            return true;
         if (obj == null || (obj instanceof SubjectKey) == false)
            return false;
         SubjectKey other = (SubjectKey) obj;
         return SubjectActions.equals(subject, other.subject)
            && separateNoTx == other.separateNoTx;
      }
   }

   /**
    * Pool by connection request information
    */
   public static class PoolByCri
      extends BasePool
   {
      public PoolByCri(final ManagedConnectionFactory mcf,
                       final InternalManagedConnectionPool.PoolParams poolParams,
                       final boolean noTxSeparatePools, 
                       final Logger log)
      {
         super(mcf, poolParams, noTxSeparatePools, log);
      }

      protected Object getKey(final Subject subject, final ConnectionRequestInfo cri, boolean separateNoTx)
      {
         return new CriKey(cri, separateNoTx);
      }
   }

   /**
    * Pool by subject and criteria
    */
   private static class CriKey
   {
      /** Identifies no connection request information */
      private static final Object NOCRI = new Object();
      
      /** The connection request information */
      private final Object cri;

      /** Separate no tx */
      private boolean separateNoTx;
      
      /** The cached hashCode */
      private int hashCode = Integer.MAX_VALUE;

      CriKey(ConnectionRequestInfo cri, boolean separateNoTx) 
      {
         this.cri = (cri == null)? NOCRI:cri;
         this.separateNoTx = separateNoTx;
      }

      public int hashCode()
      {
         if (hashCode == Integer.MAX_VALUE)
            hashCode = cri.hashCode();
         return hashCode;
      }

      public boolean equals(Object obj)
      {
         if (this == obj)
            return true;
         if (obj == null || (obj instanceof CriKey) == false)
            return false;
         CriKey other = (CriKey) obj;
         return cri.equals(other.cri) && separateNoTx == other.separateNoTx;
      }
   }

   /**
    * One pool
    */
   public static class OnePool
      extends BasePool
   {
      public OnePool(final ManagedConnectionFactory mcf,
                     final InternalManagedConnectionPool.PoolParams poolParams,
                     final boolean noTxSeparatePools, 
                     final Logger log)
      {
         super(mcf, poolParams, noTxSeparatePools, log);
      }

      protected Object getKey(final Subject subject, final ConnectionRequestInfo cri, boolean separateNoTx)
      {
         if (separateNoTx)
            return Boolean.TRUE;
         else
            return Boolean.FALSE;
      }
   }

   private static class SubjectActions implements PrivilegedAction
   {
      Subject subject;
      Subject other;
      SubjectActions(Subject subject, Subject other)
      {
         this.subject = subject;
         this.other = other;
      }
      public Object run()
      {
         Object value = null;
         if( other == null )
            value = new Integer(subject.hashCode());
         else
            value = new Boolean(subject.equals(other));
         return value;
      }
      static int hashCode(Subject subject)
      {
         SubjectActions action = new SubjectActions(subject, null);
         Integer hash = (Integer) AccessController.doPrivileged(action);
         return hash.intValue();
      }
      static boolean equals(Subject subject, Subject other)
      {
         SubjectActions action = new SubjectActions(subject, other);
         Boolean equals = (Boolean) AccessController.doPrivileged(action);
         return equals.booleanValue();
      }
   }
}
