com.bigdata.journal

Class JournalTransactionService.ValidateWriteSetTask

java.lang.Object

com.bigdata.journal.AbstractTask<Boolean>

com.bigdata.journal.JournalTransactionService.ValidateWriteSetTask

All Implemented Interfaces:

ITask<Boolean>, Callable<Boolean>

Enclosing class:

JournalTransactionService

public static class JournalTransactionService.ValidateWriteSetTask
extends AbstractTask<Boolean>

This task is an UNISOLATED operation that validates a transaction known to have non-empty write sets.

Note: DO NOT Tx.lock while you submit this task as it could cause a deadlock if there is a task ahead of you in the queue for the same tx!

Note: DO NOT use this task for a distributed transaction (one with writes on more than one DataService) since it will fail to obtain a coherent commit time for the transaction as a whole.

Author:

Bryan Thompson

Nested Class Summary

Nested classes/interfaces inherited from class com.bigdata.journal.AbstractTask

AbstractTask.DelegateTask<T>, AbstractTask.InnerReadWriteTxServiceCallable<T>, AbstractTask.InnerWriteServiceCallable<T>, AbstractTask.ResubmitException

Field Summary

Fields inherited from class com.bigdata.journal.AbstractTask

checkpointNanoTime, concurrencyManager, isReadWriteTx, log, nanoTime_assignedWorker, nanoTime_beginWork, nanoTime_finishedWork, nanoTime_submitTask, readOnly, resourceManager, taskCounters, timestamp, transactionManager, tx

Constructor Summary

Constructors

Constructor and Description
JournalTransactionService.ValidateWriteSetTask(IConcurrencyManager concurrencyManager, ILocalTransactionManager localTransactionManager, Tx state)

Method Summary

Methods

Modifier and Type	Method and Description
Boolean	doTask() Implement the task behavior here.

Methods inherited from class com.bigdata.journal.AbstractTask

assertResource, assertRunning, assertUnisolated, call, clearLoggingContext, dropIndex, getCommitTime, getIndex, getJournal, getOnlyResource, getResource, getResourceManager, getTaskCounters, getTaskName, getTimestamp, isResource, registerIndex, setupLoggingContext, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

JournalTransactionService.ValidateWriteSetTask

public JournalTransactionService.ValidateWriteSetTask(IConcurrencyManager concurrencyManager,
                                              ILocalTransactionManager localTransactionManager,
                                              Tx state)

Method Detail

doTask

public Boolean doTask()
               throws Exception

Description copied from class: AbstractTask

Implement the task behavior here.

Note: Long-running implementations MUST periodically test Thread.interrupted() and MUST throw an exception, such as InterruptedException, if they are interrupted. This behavior allows tasks to be canceled in a timely manner.

If you ignore or fail to test Thread.interrupted() then your task CAN NOT be aborted. If it is Future.cancel(boolean) with false then the task will run to completion even though it has been cancelled (but the Future will appear to have been cancelled).

If you simply return rather than throwing an exception then the WriteExecutorService will assume that your task completed and your (partial) results will be made restart-safe at the next commit!

Specified by:

doTask in class AbstractTask<Boolean>

Returns:

The object that will be returned by AbstractTask.call() iff the operation succeeds.

Throws:

Exception - The exception that will be thrown by AbstractTask.call() iff the operation fails.

InterruptedException - This exception SHOULD be thrown if Thread.interrupted() becomes true during execution.