com.arjuna.ats.internal.jts.orbspecific.interposition.coordinator

Class ServerTransaction

java.lang.Object

com.arjuna.ats.arjuna.StateManager

com.arjuna.ats.arjuna.coordinator.BasicAction

com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator

com.arjuna.ats.internal.jts.orbspecific.coordinator.ArjunaTransactionImple

com.arjuna.ats.internal.jts.orbspecific.interposition.coordinator.ServerTransaction

All Implemented Interfaces:

ArjunaTransactionOperations, UidCoordinatorOperations, Reapable, CoordinatorOperations, TerminatorOperations

Direct Known Subclasses:

RecoveredServerTransaction, ServerTransaction

public class ServerTransaction
extends ArjunaTransactionImple

This looks like an Transaction, but is only created for interposition purposes. The classes ServerTopLevelAction and ServerNestedAction use instances of this class to drive the server-side protocol.

Since:

JTS 1.0.

Version:

$Id: ServerTransaction.java 2342 2006-03-30 13:06:17Z $

Author:

Mark Little (mark@arjuna.com)

Field Summary

Fields

Modifier and Type	Field and Description
protected RecoveryCoordinator	_recoveryCoordinator

Fields inherited from class com.arjuna.ats.internal.jts.orbspecific.coordinator.ArjunaTransactionImple

controlHandle, parentTransaction

Fields inherited from class com.arjuna.ats.arjuna.coordinator.BasicAction

failedList, heuristicList, pendingList, preparedList, readonlyList, savedIntentionList

Fields inherited from class com.arjuna.ats.arjuna.StateManager

modifyingActions, objectModel, objectUid, usingActions

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ServerTransaction(Uid recoveringActUid) Used during crash recovery.
	ServerTransaction(Uid actUid, Control myParent)
	ServerTransaction(Uid actUid, Control myParent, ArjunaTransactionImple parentImpl)

Method Summary

Modifier and Type	Method and Description
void	doAfterCompletion(Status s)
void	doBeforeCompletion()
void	doCommit(boolean report_heuristics)
void	doForget()
int	doPhase2Abort()
int	doPhase2Commit()
int	doPrepare()
void	finalize()
Uid	getSavingUid()
protected int	preparedStatus()
void	register_synchronization(Synchronization theSync) Registering a synchronization with interposition is a bit complicated! Synchronizations must be called prior to prepare; if no interposed-synchronization is used then either synchronizations would be registered locally (and then ignored by the commit protocol) or they would need to be registered remotely, which would mean a cross-address space call for each synchronization! The first time a synchronization is registered locally, we register a proxy back with the real coordinator.
boolean	restore_state(InputObjectState os, int ot) This assumes the various lists are zero length when it is called.
void	rollback()
boolean	save_state(OutputObjectState os, int ot) Redefined version of save_state and restore_state from StateManager.
void	setRecoveryCoordinator(RecoveryCoordinator recCoord)
String	toString() Overloads Object.toString()
String	type() Overloads BasicAction.type()
static String	typeName()

Methods inherited from class com.arjuna.ats.internal.jts.orbspecific.coordinator.ArjunaTransactionImple

commit, create_subtransaction, createOTSRecord, createOTSRecord, destroyAction, equals, forgetHeuristics, get_parent_status, get_status, get_top_level_status, get_transaction_name, get_txcontext, getControlHandle, getSynchronizations, hash_top_level_tran, hash_transaction, interpositionType, is_ancestor_transaction, is_descendant_transaction, is_related_transaction, is_same_transaction, is_top_level_transaction, register_resource, register_subtran_aware, rollback_only, setControlHandle, topLevelUid, uid

Methods inherited from class com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator

addSynchronization, afterCompletion, afterCompletion, asyncAfterCompletion, beforeCompletion, cancel, end, getDeferredThrowable, running, start, start

Methods inherited from class com.arjuna.ats.arjuna.coordinator.BasicAction

Abort, abortStatus, activate, activate, activeThreads, add, addChildAction, addChildThread, addChildThread, addRecord, async_prepare, Begin, checkForCurrent, childTransactions, commitStatus, criticalEnd, criticalStart, Current, deactivate, destroy, doAbort, doAbort, doCommit, doCommit, doPrepare, End, finalizeInternal, getHeuristicDecision, getHierarchy, getStore, hashCode, hierarchyDepth, insertRecord, isAncestor, maintainHeuristics, onePhaseCommit, parent, phase2Abort, phase2Cleanup, phase2Commit, prepare, preventCommit, removeChildAction, removeChildThread, removeChildThread, setCheckedAction, setHeuristicDecision, status, topLevelAction, topLevelActionUid, typeOfAction, updateHeuristic, updateState

Methods inherited from class com.arjuna.ats.arjuna.StateManager

cleanup, createLists, deactivate, deactivate, disable, forgetAction, get_uid, getMutex, getObjectModel, getStoreRoot, loadObjectState, lockMutex, modified, objectType, packHeader, persist, print, rememberAction, setStatus, setupStore, setupStore, setupStore, terminate, tryLockMutex, unlockMutex, unpackHeader

Methods inherited from class java.lang.Object

clone, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.arjuna.ats.arjuna.coordinator.Reapable

get_uid, preventCommit

Field Detail

_recoveryCoordinator

protected RecoveryCoordinator _recoveryCoordinator

Constructor Detail

ServerTransaction

public ServerTransaction(Uid actUid,
                         Control myParent)

ServerTransaction

public ServerTransaction(Uid actUid,
                         Control myParent,
                         ArjunaTransactionImple parentImpl)

ServerTransaction

protected ServerTransaction(Uid recoveringActUid)

Used during crash recovery. The Uid is the identity of the state which this transaction's log is stored in. It is not the identity of the transaction! Therefore you may pass nullUid to the base transaction and rely on activating the transaction state to set up the transaction id.

Method Detail

finalize

public void finalize()

Overrides:

finalize in class ArjunaTransactionImple

type

public String type()

Description copied from class: TwoPhaseCoordinator

Overloads BasicAction.type()

Overrides:

type in class ArjunaTransactionImple

getSavingUid

public Uid getSavingUid()

Overrides:

getSavingUid in class BasicAction

Returns:

the Uid that the transaction's intentions list will be saved under.

doPrepare

public final int doPrepare()

doForget

public final void doForget()

doPhase2Commit

public final int doPhase2Commit()

doPhase2Abort

public final int doPhase2Abort()

doCommit

public void doCommit(boolean report_heuristics)
              throws HeuristicHazard,
                     SystemException

Throws:

HeuristicHazard

SystemException

rollback

public void rollback()
              throws SystemException

Specified by:

rollback in interface TerminatorOperations

Overrides:

rollback in class ArjunaTransactionImple

Throws:

SystemException

register_synchronization

public void register_synchronization(Synchronization theSync)
                              throws Inactive,
                                     SynchronizationUnavailable,
                                     SystemException

Registering a synchronization with interposition is a bit complicated! Synchronizations must be called prior to prepare; if no interposed-synchronization is used then either synchronizations would be registered locally (and then ignored by the commit protocol) or they would need to be registered remotely, which would mean a cross-address space call for each synchronization! The first time a synchronization is registered locally, we register a proxy back with the real coordinator. When that transaction commits, it will call this proxy, which will then drive the locally registered synchronizations (actually it calls appropriate on the transaction to do this.) However, one-phase commit complicates matters even more since we call commit on the interposed coordinator, which runs through the commit and then the after_completion code before returning to the real coordinator's commit call. Rather than separate commit and synchronization code completely from the transaction (in which case we could just call the commit portion here) we let after_completion get called before returning the commit response, and simply ignore the real coordinator's subsequent call to after_completion.

Specified by:

register_synchronization in interface CoordinatorOperations

Overrides:

register_synchronization in class ArjunaTransactionImple

Throws:

Inactive

SynchronizationUnavailable

SystemException

doBeforeCompletion

public void doBeforeCompletion()
                        throws SystemException

Overrides:

doBeforeCompletion in class ArjunaTransactionImple

Throws:

SystemException

doAfterCompletion

public void doAfterCompletion(Status s)
                       throws SystemException

Overrides:

doAfterCompletion in class ArjunaTransactionImple

Throws:

SystemException

typeName

public static String typeName()

setRecoveryCoordinator

public final void setRecoveryCoordinator(RecoveryCoordinator recCoord)

save_state

public boolean save_state(OutputObjectState os,
                          int ot)

Description copied from class: BasicAction

Redefined version of save_state and restore_state from StateManager. Normal operation (no crashes): BasicAction.save_state is called after a successful prepare. This causes and BasicAction object to be saved in the object store. This object contains primarily the "intentions list" of the BasicAction. After successfully completing phase 2 of the commit protocol, the BasicAction object is deleted from the store. Failure cases: If a server crashes after successfully preparing, then upon recovery the action must be resolved (either committed or aborted) depending upon whether the co-ordinating atomic action committed or aborted. Upon server recovery, the crash recovery mechanism detects ServerBasicAction objects in the object store and attempts to activate the BasicAction object of the co-ordinating action. If this is successful then the SAA is committed else aborted. If, when processing phase 2 of the commit protocol, the co-ordinator experiences a failure to commit from one of the records then the BasicAction object is NOT deleted. It is rewritten when a new state which contains a list of the records that failed during phase 2 commit. This list is called the "failedList". The crash recovery manager will detect local BasicAction objects in addition to SAA objects in the objectstore. An attempt will be made to commit these actions. If the action contained a call to a now dead server, this action can never be resolved and the AA object can never be removed. However, if the action is purely local then after the processing is complete the removed by crash recovery.

Overrides:

save_state in class BasicAction

Returns:

true if successful, false otherwise.

restore_state

public boolean restore_state(InputObjectState os,
                             int ot)

Description copied from class: BasicAction

This assumes the various lists are zero length when it is called.

Overrides:

restore_state in class BasicAction

Returns:

true if successful, false otherwise.

toString

public String toString()

Description copied from class: BasicAction

Overloads Object.toString()

Overrides:

toString in class ArjunaTransactionImple

preparedStatus

protected final int preparedStatus()

Overrides:

preparedStatus in class BasicAction

Returns:

the transaction's prepared status.