org.infinispan.interceptors.locking

Class AbstractTxLockingInterceptor

java.lang.Object

org.infinispan.commands.AbstractVisitor

org.infinispan.interceptors.base.CommandInterceptor

org.infinispan.interceptors.locking.AbstractLockingInterceptor

org.infinispan.interceptors.locking.AbstractTxLockingInterceptor

All Implemented Interfaces:

Visitor

Direct Known Subclasses:

OptimisticLockingInterceptor, PessimisticLockingInterceptor

public abstract class AbstractTxLockingInterceptor
extends AbstractLockingInterceptor

Base class for transaction based locking interceptors.

Since:

5.1

Author:

Mircea.Markus@jboss.com

Field Summary

Fields

Modifier and Type	Field and Description
protected RpcManager	rpcManager
protected TransactionTable	txTable

Fields inherited from class org.infinispan.interceptors.locking.AbstractLockingInterceptor

cdl, dataContainer, entryFactory, lockManager

Fields inherited from class org.infinispan.interceptors.base.CommandInterceptor

cacheConfiguration

Constructor Summary

Constructors

Constructor and Description
AbstractTxLockingInterceptor()

Method Summary

Modifier and Type	Method and Description
protected Object	invokeNextAndCommitIf1Pc(TxInvocationContext ctx, PrepareCommand command)
protected void	lockAndRegisterBackupLock(TxInvocationContext ctx, Object key, long lockTimeout, boolean skipLocking) The backup (non-primary) owners keep a "backup lock" for each key they received in a lock/prepare command.
protected void	lockKeyAndCheckOwnership(InvocationContext ctx, Object key, long lockTimeout, boolean skipLocking) Besides acquiring a lock, this method also handles the following situation: 1.
void	setDependencies(TransactionTable txTable, RpcManager rpcManager, TimeService timeService)
Object	visitCommitCommand(TxInvocationContext ctx, CommitCommand command)
Object	visitGetKeyValueCommand(InvocationContext ctx, GetKeyValueCommand command)
Object	visitRollbackCommand(TxInvocationContext ctx, RollbackCommand command)

Methods inherited from class org.infinispan.interceptors.locking.AbstractLockingInterceptor

cleanLocksAndRethrow, lockKey, lockKey, setDependencies, shouldLock, visitEvictCommand, visitInvalidateCommand, visitInvalidateL1Command, visitPutKeyValueCommand

Methods inherited from class org.infinispan.interceptors.base.CommandInterceptor

getLockAcquisitionTimeout, getLog, getNext, handleDefault, hasNext, hasSkipLocking, injectConfiguration, invokeNextInterceptor, setNext

Methods inherited from class org.infinispan.commands.AbstractVisitor

visitApplyDeltaCommand, visitClearCommand, visitCollection, visitDistributedExecuteCommand, visitEntrySetCommand, visitKeySetCommand, visitLockControlCommand, visitPrepareCommand, visitPutMapCommand, visitRemoveCommand, visitReplaceCommand, visitSizeCommand, visitUnknownCommand, visitValuesCommand

Methods inherited from class java.lang.Object

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

Field Detail

txTable

protected TransactionTable txTable

rpcManager

protected RpcManager rpcManager

Constructor Detail

AbstractTxLockingInterceptor

public AbstractTxLockingInterceptor()

Method Detail

setDependencies

public void setDependencies(TransactionTable txTable,
                            RpcManager rpcManager,
                            TimeService timeService)

visitRollbackCommand

public Object visitRollbackCommand(TxInvocationContext ctx,
                                   RollbackCommand command)
                            throws Throwable

Specified by:

visitRollbackCommand in interface Visitor

Overrides:

visitRollbackCommand in class AbstractVisitor

Throws:

Throwable

visitGetKeyValueCommand

public Object visitGetKeyValueCommand(InvocationContext ctx,
                                      GetKeyValueCommand command)
                               throws Throwable

Specified by:

visitGetKeyValueCommand in interface Visitor

Overrides:

visitGetKeyValueCommand in class AbstractVisitor

Throws:

Throwable

visitCommitCommand

public Object visitCommitCommand(TxInvocationContext ctx,
                                 CommitCommand command)
                          throws Throwable

Specified by:

visitCommitCommand in interface Visitor

Overrides:

visitCommitCommand in class AbstractVisitor

Throws:

Throwable

invokeNextAndCommitIf1Pc

protected final Object invokeNextAndCommitIf1Pc(TxInvocationContext ctx,
                                                PrepareCommand command)
                                         throws Throwable

Throws:

Throwable

lockAndRegisterBackupLock

protected final void lockAndRegisterBackupLock(TxInvocationContext ctx,
                                               Object key,
                                               long lockTimeout,
                                               boolean skipLocking)
                                        throws InterruptedException

The backup (non-primary) owners keep a "backup lock" for each key they received in a lock/prepare command. Normally there can be many transactions holding the backup lock at the same time, but when the secondary owner becomes a primary owner a new transaction trying to obtain the "real" lock will have to wait for all backup locks to be released. The backup lock will be released either by a commit/rollback/unlock command or by the originator leaving the cluster (if recovery is disabled).

Throws:

InterruptedException

lockKeyAndCheckOwnership

protected final void lockKeyAndCheckOwnership(InvocationContext ctx,
                                              Object key,
                                              long lockTimeout,
                                              boolean skipLocking)
                                       throws InterruptedException

Besides acquiring a lock, this method also handles the following situation: 1. consistentHash("k") == {A, B}, tx1 prepared on A and B. Then node A crashed (A == single lock owner) 2. at this point tx2 which also writes "k" tries to prepare on B. 3. tx2 has to determine that "k" is already locked by another tx (i.e. tx1) and it has to wait for that tx to finish before acquiring the lock. The algorithm used at step 3 is: - the transaction table(TT) associates the current topology id with every remote and local transaction it creates - TT also keeps track of the minimal value of all the topology ids of all the transactions still present in the cache (minTopologyId) - when a tx wants to acquire lock "k": - if tx.topologyId > TT.minTopologyId then "k" might be a key whose owner crashed. If so: - obtain the list LT of transactions that started in a previous topology (txTable.getTransactionsPreparedBefore) - for each t in LT: - if t wants to write "k" then block until t finishes (CacheTransaction.waitForTransactionsToFinishIfItWritesToKey) - only then try to acquire lock on "k" - if tx.topologyId == TT.minTopologyId try to acquire lock straight away. Note: The algorithm described below only when nodes leave the cluster, so it doesn't add a performance burden when the cluster is stable.

Throws:

InterruptedException