com.arjuna.ats.arjuna

Class AtomicAction

java.lang.Object

com.arjuna.ats.arjuna.StateManager

com.arjuna.ats.arjuna.coordinator.BasicAction

com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator

com.arjuna.ats.arjuna.AtomicAction

All Implemented Interfaces:

Reapable

Direct Known Subclasses:

RecoverAtomicAction, TopLevelAction

public class AtomicAction
extends TwoPhaseCoordinator

This is a user-level transaction class, unlike BasicAction. AtomicAction takes care of thread-to-action scoping. This is a "one-shot" object, i.e., once terminated, the instance cannot be re-used for another transaction. An instance of this class is a transaction that can be started and terminated (either committed or rolled back). There are also methods to allow participants (AbstractRecords) to be enlisted with the transaction and to associate/disassociate threads with the transaction.

Since:

JTS 1.0.

Version:

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

Author:

Mark Little (mark@arjuna.com)

Field Summary

Fields

Modifier and Type	Field and Description
static int	NO_TIMEOUT

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
	AtomicAction() Create a new transaction.
protected	AtomicAction(int at) Create a new transaction of the specified type.
	AtomicAction(Uid objUid) AtomicAction constructor with a Uid.

Method Summary

Methods

Modifier and Type	Method and Description
int	abort() Abort (rollback) the transaction.
boolean	addThread() Register the current thread with the transaction.
boolean	addThread(Thread t) Register the specified thread with the transaction.
int	begin() Start the transaction running.
int	begin(int timeout) Start the transaction running.
int	cancel()
protected boolean	checkForCurrent() By default the BasicAction class only allows the termination of a transaction if it's the one currently associated with the thread.
int	commit() Commit the transaction, and have heuristic reporting.
int	commit(boolean report_heuristics) Commit the transaction.
int	end(boolean report_heuristics)
int	getTimeout()
boolean	removeThread() Unregister the current thread from the transaction.
boolean	removeThread(Thread t) Unregister the specified thread from the transaction.
static boolean	resume(AtomicAction act) Resume transaction association on the current thread.
static AtomicAction	suspend() Suspend all transaction association from the invoking thread.
String	type() The type of the class is used to locate the state of the transaction log in the object store.

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

addSynchronization, afterCompletion, afterCompletion, beforeCompletion, getDeferredThrowable, getSynchronizations, 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, childTransactions, commitStatus, criticalEnd, criticalStart, Current, deactivate, destroy, doAbort, doAbort, doCommit, doCommit, doPrepare, End, equals, finalizeInternal, forgetHeuristics, getHeuristicDecision, getHierarchy, getSavingUid, getStore, hashCode, hierarchyDepth, insertRecord, isAncestor, maintainHeuristics, onePhaseCommit, parent, phase2Abort, phase2Cleanup, phase2Commit, prepare, preparedStatus, preventCommit, removeChildAction, removeChildThread, removeChildThread, restore_state, save_state, setCheckedAction, setHeuristicDecision, status, topLevelAction, topLevelActionUid, toString, 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, finalize, getClass, notify, notifyAll, wait, wait, wait

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

get_uid, preventCommit

Field Detail

NO_TIMEOUT

public static final int NO_TIMEOUT

See Also:

Constant Field Values

Constructor Detail

AtomicAction

public AtomicAction()

Create a new transaction. If there is already a transaction associated with the thread then this new transaction will be automatically nested. The transaction is *not* running at this point. No timeout is associated with this transaction, i.e., it will not be automatically rolled back by the system.

AtomicAction

public AtomicAction(Uid objUid)

AtomicAction constructor with a Uid. This constructor is for recreating an AtomicAction, typically during crash recovery.

AtomicAction

protected AtomicAction(int at)

Create a new transaction of the specified type.

Method Detail

begin

public int begin()

Start the transaction running. If the transaction is already running or has terminated, then an error code will be returned. No timeout is associated with the transaction.

Returns:

ActionStatus indicating outcome.

begin

public int begin(int timeout)

Start the transaction running. If the transaction is already running or has terminated, then an error code will be returned.

Parameters:

timeout - the timeout associated with the transaction. If the transaction is still active when this timeout elapses, the system will automatically roll it back.

Returns:

ActionStatus indicating outcome.

commit

public int commit()

Commit the transaction, and have heuristic reporting. Heuristic reporting via the return code is enabled.

Returns:

ActionStatus indicating outcome.

commit

public int commit(boolean report_heuristics)

Commit the transaction. The report_heuristics parameter can be used to determine whether or not heuristic outcomes are reported. If the transaction has already terminated, or has not begun, then an appropriate error code will be returned.

Returns:

ActionStatus indicating outcome.

abort

public int abort()

Abort (rollback) the transaction. If the transaction has already terminated, or has not been begun, then an appropriate error code will be returned.

Returns:

ActionStatus indicating outcome.

end

public int end(boolean report_heuristics)

Overrides:

end in class TwoPhaseCoordinator

cancel

public int cancel()

Specified by:

cancel in interface Reapable

Overrides:

cancel in class TwoPhaseCoordinator

getTimeout

public final int getTimeout()

type

public String type()

The type of the class is used to locate the state of the transaction log in the object store. Overloads BasicAction.type()

Overrides:

type in class TwoPhaseCoordinator

Returns:

a string representation of the hierarchy of the class for storing logs in the transaction object store.

addThread

public boolean addThread()

Register the current thread with the transaction. This operation is not affected by the state of the transaction.

Returns:

true if successful, false otherwise.

addThread

public boolean addThread(Thread t)

Register the specified thread with the transaction. This operation is not affected by the state of the transaction.

Returns:

true if successful, false otherwise.

removeThread

public boolean removeThread()

Unregister the current thread from the transaction. This operation is not affected by the state of the transaction.

Returns:

true if successful, false otherwise.

removeThread

public boolean removeThread(Thread t)

Unregister the specified thread from the transaction. This operation is not affected by the state of the transaction.

Returns:

true if successful, false otherwise.

suspend

public static final AtomicAction suspend()

Suspend all transaction association from the invoking thread. When this operation returns, the thread will be associated with no transactions. If the current transaction is not an AtomicAction then this method will not suspend.

Returns:

a handle on the current AtomicAction (if any) so that the thread can later resume association if required.

resume

public static final boolean resume(AtomicAction act)

Resume transaction association on the current thread. If the specified transaction is null, then this is the same as doing a suspend. If the current thread is associated with transactions then those associations will be lost.

Parameters:

act - the transaction to associate. If this is a nested transaction, then the thread will be associated with all of the transactions in the hierarchy.

Returns:

true if association is successful, false otherwise.

checkForCurrent

protected boolean checkForCurrent()

By default the BasicAction class only allows the termination of a transaction if it's the one currently associated with the thread. We override this here.

Overrides:

checkForCurrent in class BasicAction

Returns:

true to indicate that this transaction can only be terminated by the right thread.