org.corfudb.runtime.object.transactions

Class AbstractTransactionalContext

java.lang.Object

org.corfudb.runtime.object.transactions.AbstractTransactionalContext

All Implemented Interfaces:

Comparable<AbstractTransactionalContext>

Direct Known Subclasses:

OptimisticTransactionalContext, SnapshotTransactionalContext

public abstract class AbstractTransactionalContext
extends Object
implements Comparable<AbstractTransactionalContext>

Represents a transactional context. Transactional contexts manage per-thread transaction state.

Recall from CorfuCompileProxy that an SMR object layer implements objects whose history of updates are backed by a stream. If a Corfu object's method is an Accessor, it invokes the proxy's access() method. Likewise, if a Corfu object's method is a Mutator or Accessor-Mutator, it invokes the proxy's logUpdate() method.

Within transactional context, these methods invoke the transactionalContext accessor/mutator helper.

For example, OptimisticTransactionalContext.access() is responsible for sync'ing the proxy state to the snapshot version, and then doing the access.

logUpdate() within transactional context is responsible for updating the write-set.

Finally, if a Corfu object's method is an Accessor-Mutator, then although the mutation is delayed, it needs to obtain the result by invoking getUpcallResult() on the optimistic stream. This is similar to the second stage of access(), except working on the optimistic stream instead of the underlying stream.

Created by mwei on 4/4/16.

Field Summary

Fields

Modifier and Type	Field and Description
static long	ABORTED_ADDRESS Constant for a transaction which has been aborted.
long	commitAddress The address that the transaction was committed at.
CompletableFuture<Boolean>	completionFuture A future which gets completed when this transaction commits.
static long	FOLDED_ADDRESS Constant for a transaction which has been folded into another transaction.
static long	NOWRITE_ADDRESS Constant for committing a transaction which did not modify the log at all.
long	startTime The start time of the context.
Transaction	transaction The builder used to create this transaction.
UUID	transactionID The ID of the transaction.
static long	UNCOMMITTED_ADDRESS Constant for the address of an uncommitted log entry.

Method Summary

Modifier and Type	Method and Description
void	abortTransaction(TransactionAbortedException ae) Forcefully abort the transaction.
abstract <R,T> R	access(ICorfuSMRProxyInternal<T> proxy, ICorfuSMRAccess<R,T> accessFunction, Object[] conflictObject) Access the state of the object.
void	addToReadSet(ICorfuSMRProxyInternal proxy, Object[] conflictObjects) Add the proxy and conflict-params information to our read set.
abstract void	addTransaction(AbstractTransactionalContext tc) Add a given transaction to this transactional context, merging the read and write sets.
long	commitTransaction() Commit the transaction to the log.
int	compareTo(AbstractTransactionalContext o) Transactions are ordered by their snapshot timestamp.
abstract <T> Object	getUpcallResult(ICorfuSMRProxyInternal<T> proxy, long timestamp, Object[] conflictObject) Get the result of an upcall.
abstract <T> long	logUpdate(ICorfuSMRProxyInternal<T> proxy, SMREntry updateEntry, Object[] conflictObject) Log an SMR update to the Corfu log.
void	syncWithRetryUnsafe(VersionLockedObject vlo, Token snapshotTimestamp, ICorfuSMRProxyInternal proxy, Consumer<VersionLockedObject> optimisticStreamSetter)
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

UNCOMMITTED_ADDRESS

public static final long UNCOMMITTED_ADDRESS

Constant for the address of an uncommitted log entry.

See Also:

Constant Field Values

FOLDED_ADDRESS

public static final long FOLDED_ADDRESS

Constant for a transaction which has been folded into another transaction.

See Also:

Constant Field Values

ABORTED_ADDRESS

public static final long ABORTED_ADDRESS

Constant for a transaction which has been aborted.

See Also:

Constant Field Values

NOWRITE_ADDRESS

public static final long NOWRITE_ADDRESS

Constant for committing a transaction which did not modify the log at all.

See Also:

Constant Field Values

transactionID

public UUID transactionID

The ID of the transaction. This is used for tracking only, it is NOT recorded in the log.

transaction

public final Transaction transaction

The builder used to create this transaction.

startTime

public final long startTime

The start time of the context.

commitAddress

public long commitAddress

The address that the transaction was committed at.

completionFuture

public CompletableFuture<Boolean> completionFuture

A future which gets completed when this transaction commits. It is completed exceptionally when the transaction aborts.

Method Detail

access

public abstract <R,T> R access(ICorfuSMRProxyInternal<T> proxy,
                               ICorfuSMRAccess<R,T> accessFunction,
                               Object[] conflictObject)

Access the state of the object.

Type Parameters:

R - The return type of the access function.

T - The type of the proxy's underlying object.

Parameters:

proxy - The proxy to access the state for.

accessFunction - The function to execute, which will be provided with the state of the object.

conflictObject - Fine-grained conflict information, if available.

Returns:

The return value of the access function.

getUpcallResult

public abstract <T> Object getUpcallResult(ICorfuSMRProxyInternal<T> proxy,
                                           long timestamp,
                                           Object[] conflictObject)

Get the result of an upcall.

Type Parameters:

T - The type of the proxy's underlying object.

Parameters:

proxy - The proxy to retrieve the upcall for.

timestamp - The timestamp to return the upcall for.

conflictObject - Fine-grained conflict information, if available.

Returns:

The result of the upcall.

syncWithRetryUnsafe

public void syncWithRetryUnsafe(VersionLockedObject vlo,
                                Token snapshotTimestamp,
                                ICorfuSMRProxyInternal proxy,
                                @Nullable
                                Consumer<VersionLockedObject> optimisticStreamSetter)

logUpdate

public abstract <T> long logUpdate(ICorfuSMRProxyInternal<T> proxy,
                                   SMREntry updateEntry,
                                   Object[] conflictObject)

Log an SMR update to the Corfu log.

Type Parameters:

T - The type of the proxy's underlying object.

Parameters:

proxy - The proxy which generated the update.

updateEntry - The entry which we are writing to the log.

conflictObject - Fine-grained conflict information, if available.

Returns:

The address the update was written at.

addTransaction

public abstract void addTransaction(AbstractTransactionalContext tc)

Add a given transaction to this transactional context, merging the read and write sets.

Parameters:

tc - The transactional context to merge.

commitTransaction

public long commitTransaction()
                       throws TransactionAbortedException

Commit the transaction to the log.

Throws:

TransactionAbortedException - If the transaction is aborted.

abortTransaction

public void abortTransaction(TransactionAbortedException ae)

Forcefully abort the transaction.

addToReadSet

public void addToReadSet(ICorfuSMRProxyInternal proxy,
                         Object[] conflictObjects)

Add the proxy and conflict-params information to our read set.

Parameters:

proxy - The proxy to add

conflictObjects - The fine-grained conflict information, if available.

compareTo

public int compareTo(AbstractTransactionalContext o)

Transactions are ordered by their snapshot timestamp.

Specified by:

compareTo in interface Comparable<AbstractTransactionalContext>

toString

public String toString()

Overrides:

toString in class Object