PoolTxHelper.java

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package com.sun.enterprise.resource.pool;

import com.sun.enterprise.connectors.ConnectorRuntime;
import com.sun.enterprise.resource.ResourceHandle;
import com.sun.enterprise.resource.ResourceState;
import com.sun.enterprise.transaction.api.JavaEETransaction;
import com.sun.logging.LogDomains;
import org.glassfish.resourcebase.resources.api.PoolInfo;

import javax.transaction.SystemException;
import javax.transaction.Transaction;
import java.util.*;
import java.util.logging.Level;
import java.util.logging.Logger;


/**
 * Transaction helper for the pool to check various states of a resource that is taking part in the transaction.
 * @author Jagadish Ramu
 */
public class PoolTxHelper {

    private PoolInfo poolInfo;

    protected final static Logger _logger = LogDomains.getLogger(PoolTxHelper.class, LogDomains.RSR_LOGGER);

    public PoolTxHelper(PoolInfo poolInfo){
        this.poolInfo = poolInfo;
    }

    /**
     * Check whether the local resource can be put back to pool
     * If true, unenlist the resource
     *
     * @param h ResourceHandle to be verified
     * @return boolean
     */
    public boolean isLocalResourceEligibleForReuse(ResourceHandle h) {
        boolean result = false;
        if ((!isLocalResourceInTransaction(h))) {
            try {
                enforceDelistment(h);
            } catch (SystemException se) {
                if (_logger.isLoggable(Level.FINE)) {
                    _logger.log(Level.FINE, "Exception while delisting the local resource [ of pool : " + poolInfo + " ] "
                            + "forcibily from transaction", se);
                }
                return result;
            }
            h.getResourceState().setEnlisted(false);
            result = true;
        }
        return result;
    }

    /**
     * Remove the resource from book-keeping
     *
     * @param h ResourceHandle to be delisted
     * @throws javax.transaction.SystemException when not able to delist the resource
     */
    private void enforceDelistment(ResourceHandle h) throws SystemException {
        JavaEETransaction txn = (JavaEETransaction) ConnectorRuntime.getRuntime().getTransaction();
        if (txn != null) {
            Set set = txn.getResources(poolInfo);
            if (set != null)
                set.remove(h);
        }
    }

    /**
     * Check whether a local transaction is in progress.
     * 
     * @return true if a local transaction is in progress.
     */
    public boolean isLocalTransactionInProgress() {
        boolean result = false;
        try {
            JavaEETransaction txn = (JavaEETransaction) ConnectorRuntime.getRuntime().getTransaction();
            if(txn != null) {
                result = txn.isLocalTx();
            }
        } catch (SystemException e) {
            if (_logger.isLoggable(Level.FINE)) {
                _logger.log(Level.FINE, "Exception while checking whether a local "
                        + "transaction is in progress while using pool : " + poolInfo, e);
            }
        }
        return result;
    }
    /**
     * Check whether the local resource in question is the one participating in transaction.
     *
     * @param h ResourceHandle
     * @return true if the resource is  participating in the transaction
     */
    public boolean isLocalResourceInTransaction(ResourceHandle h) {
        boolean result = true;
        try {
            JavaEETransaction txn = (JavaEETransaction) ConnectorRuntime.getRuntime().getTransaction();
            if (txn != null)
                result = isNonXAResourceInTransaction(txn, h);
        } catch (SystemException e) {
            if (_logger.isLoggable(Level.FINE)) {
                _logger.log(Level.FINE, "Exception while checking whether the resource [ of pool : " + poolInfo + " ] "
                        + "is nonxa and is enlisted in transaction : ", e);
            }
        }
        return result;
    }

    /**
     * Check whether the resource is non-xa
     *
     * @param resource Resource to be verified
     * @return boolean indicating whether the resource is non-xa
     */
    public boolean isNonXAResource(ResourceHandle resource) {
        return !resource.getResourceSpec().isXA();
    }

    /**
     * Check whether the non-xa resource is enlisted in transaction.
     *
     * @param tran     Transaction
     * @param resource Resource to be verified
     * @return boolean indicating whether thegiven non-xa  resource is in transaction
     */
    private boolean isNonXAResourceInTransaction(JavaEETransaction tran, ResourceHandle resource) {

        return resource.equals(tran.getNonXAResource());
    }

    /**
     * Check whether the resource is non-xa, free and is enlisted in transaction.
     *
     * @param tran     Transaction
     * @param resource Resource to be verified
     * @return boolean indicating whether the resource is free, non-xa and is enlisted in transaction
     */
    public boolean isNonXAResourceAndFree(JavaEETransaction tran, ResourceHandle resource) {
        return resource.getResourceState().isFree() && isNonXAResource(resource) && isNonXAResourceInTransaction(tran, resource);
    }

    /**
     * this method is called when a resource is enlisted in
     * transation tran
     * @param tran Transaction to which the resource need to be enlisted
     * @param resource Resource to be enlisted in the transaction
     */
    public void resourceEnlisted(Transaction tran, ResourceHandle resource) {
        try {
            JavaEETransaction j2eetran = (JavaEETransaction) tran;
            Set set = j2eetran.getResources(poolInfo);
            if (set == null) {
                set = new HashSet();
                j2eetran.setResources(set, poolInfo);
            }
            set.add(resource);
        } catch (ClassCastException e) {
            if (_logger.isLoggable(Level.FINE)) {
                _logger.log(Level.FINE, "Pool [ " + poolInfo + " ]: resourceEnlisted:"
                        + "transaction is not J2EETransaction but a " + tran.getClass().getName(), e);
            }
        }
        ResourceState state = resource.getResourceState();
        state.setEnlisted(true);
        if (_logger.isLoggable(Level.FINE)) {
            _logger.log(Level.FINE, "Pool [ "+ poolInfo +" ]: resourceEnlisted: " + resource);
        }
    }

    /**
     * this method is called when transaction tran is completed
     * @param tran transaction which has completed
     * @param status transaction status
     * @param poolInfo Pool name
     * @return delisted resources
     */
    public List<ResourceHandle> transactionCompleted(Transaction tran, int status, PoolInfo poolInfo) {
        JavaEETransaction j2eetran;
        List<ResourceHandle> delistedResources = new ArrayList<ResourceHandle>();
        try {
             j2eetran = (JavaEETransaction) tran;
        } catch (ClassCastException e) {
            if (_logger.isLoggable(Level.FINE)) {
                _logger.log(Level.FINE, "Pool: transactionCompleted: "
                        + "transaction is not J2EETransaction but a " + tran.getClass().getName(), e);
            }
            return delistedResources;
        }
        Set set = j2eetran.getResources(poolInfo);

        if (set == null) return delistedResources;

        Iterator iter = set.iterator();
        while (iter.hasNext()) {
            ResourceHandle resource = (ResourceHandle) iter.next();
            ResourceState state = resource.getResourceState();
            state.setEnlisted(false);
            delistedResources.add(resource);
            iter.remove();
            if (_logger.isLoggable(Level.FINE)) {
                _logger.log(Level.FINE, "Pool: transactionCompleted: " + resource);
            }
        }
        return delistedResources;
    }
}