org.omg.CosTransactions
Interface ResourceOperations

All Known Subinterfaces:

Resource, SubtransactionAwareResource, SubtransactionAwareResourceOperations

All Known Implementing Classes:

_ResourceStub, _SubtransactionAwareResourceStub, ResourcePOA, SubtransactionAwareResourcePOA

public interface ResourceOperations

The Resource interface defines the operations invoked by the transaction service on each resource that is a participant in a transaction.

Method Summary

void	commit_one_phase() If possible, the resource should commit all changes made as part of the transaction.
void	commit() This operation is invoked to complete the two-phase commit.
void	forget() This operation is performed only if the resource raised a heuristic outcome exception to rollback, commit, commit_one_phase, or prepare.
Vote	prepare() This operation is invoked to begin the two-phase commit protocol on the resource.
void	rollback() This operation is can be invoked to complete the two-phase commit.

Method Detail

prepare

public Vote prepare()
             throws HeuristicMixed,
                    HeuristicHazard

This operation is invoked to begin the two-phase commit protocol on the resource. The resource can respond in several ways, represented by the Vote result.

If no persistent data associated with the resource has been modified by the transaction, the resource can return VoteReadOnly. After receiving this response, the Transaction Service is not required to perform any additional operations on this resource. Furthermore, the resource can forget all knowledge of the transaction.

If the resource is able to write (or has already written) all the data needed to commit the transaction to stable storage, as well as an indication that it has prepared the transaction, it can return VoteCommit. After receiving this response, the Transaction Service is required to eventually perform either the commit or the rollback operation on this object.

The resource can return VoteRollback under any circumstances, including not having any knowledge about the transaction (which might happen after a crash). If this response is returned, the transaction must be rolled back.

Throws:

HeuristicMixed

HeuristicHazard

rollback

public void rollback()
              throws HeuristicCommit,
                     HeuristicMixed,
                     HeuristicHazard

This operation is can be invoked to complete the two-phase commit. If necessary, the resource should rollback all changes made as part of the transaction.

Throws:

HeuristicCommit

HeuristicMixed

HeuristicHazard

commit

public void commit()
            throws NotPrepared,
                   HeuristicRollback,
                   HeuristicMixed,
                   HeuristicHazard

This operation is invoked to complete the two-phase commit. If necessary, the resource should commit all changes made as part of the transaction.

The NotPrepared exception is raised if the commit operation is performed without first performing the prepare operation.

Throws:

NotPrepared

HeuristicRollback

HeuristicMixed

HeuristicHazard

commit_one_phase

public void commit_one_phase()
                      throws HeuristicHazard

If possible, the resource should commit all changes made as part of the transaction.

Throws:

HeuristicHazard

forget

public void forget()

This operation is performed only if the resource raised a heuristic outcome exception to rollback, commit, commit_one_phase, or prepare. Once the coordinator has determined that the heuristic situation has been addressed, it should issue forget on the resource. The resource can forget all knowledge of the transaction.