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public class: XactXAResourceManager [javadoc | source]

All Implemented Interfaces:

The XactXAResourceManager implements the Access XAResource interface, which provides offline control over two phase commit transactions. It is expected to be used by TM's (transaction manager's), to recover if systems fail while transactions are still in-doubt (prepared).

This interface allows access to commit,prepare,abort global transactions as part of a two phase commit protocol. These interfaces have been chosen to be exact implementations required to implement the XAResource interfaces as part of the JTA standard extension.

It is expected that the following interfaces are only used during the recovery portion of 2 phase commit, when the transaction manager is cleaning up after a runtime crash - it is expected that no current context managers exist for the Xid's being operated on. The "online" two phase commit protocol will be implemented by calls directly on a TransactionController.

The XAResource interface is a Java mapping of the industry standard XA resource manager interface. Please refer to: X/Open CAE Specification - Distributed Transaction Processing: The XA Specification, X/Open Document No. XO/CAE/91/300 or ISBN 1 872630 24 3.

 public XactXAResourceManager(RawStoreFactory rsf,
    TransactionTable tt) 
    Constructors for This class:
Method from org.apache.derby.impl.store.raw.xact.XactXAResourceManager Summary:
commit,   find,   forget,   recover,   rollback
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from org.apache.derby.impl.store.raw.xact.XactXAResourceManager Detail:
 public  void commit(ContextManager cm,
    Xid xid,
    boolean onePhase) throws StandardException 
    This method is called to commit the global transaction specified by xid.

    RESOLVE - how do we map to the "right" XAExceptions.

 public ContextManager find(Xid xid) 
    Find the given Xid in the transaction table.

    This routine is used to find a in-doubt transaction from the list of Xid's returned from the recover() routine.

    In the current implementation it is up to the calling routine to make the returned ContextManager the "current" ContextManager before calls to commit,abort, or forget. The caller is responsible for error handling, ie. calling cleanupOnError() on the correct ContextManager.

    If the Xid is not in the system, "null" is returned. RESOLVE - find out from sku if she wants a exception instead?

 public  void forget(ContextManager cm,
    Xid xid) throws StandardException 
    This method is called to remove the given transaction from the transaction table/log.

    Used to let the store remove all record from log and transaction table of the given transaction. This should only be used to clean up heuristically completed transactions, otherwise commit or abort should be used to act on other transactions.

 public Xid[] recover(int flags) throws StandardException 
    This method is called to obtain a list of prepared transactions.

    This call returns a complete list of global transactions which are either prepared or heuristically complete.

    The XAResource interface expects a scan type interface, but our implementation only returns a complete list of transactions. So to simulate the scan the following state is maintained. If TMSTARTSCAN is specified the complete list is returned. If recover is called with TMNOFLAGS is ever called a 0 length array is returned.

 public  void rollback(ContextManager cm,
    Xid xid) throws StandardException 
    rollback the transaction identified by Xid.

    The given transaction is roll'ed back and it's history is not maintained in the transaction table or long term log.