com.sleepycat.je.rep.txn

Class ReplicaThreadLocker

java.lang.Object

com.sleepycat.je.txn.Locker

com.sleepycat.je.txn.BasicLocker

com.sleepycat.je.txn.ThreadLocker

com.sleepycat.je.rep.txn.ReplicaThreadLocker

public class ReplicaThreadLocker
extends ThreadLocker

A ReplicaThreadLocker is used with a user initiated non-transactional operation on a Replica, for a replicated DB. Like ReadonlyTxn, it enforces read-only semantics and implements the ReplicaConsistencyPolicy. Unlike ReadonlyTxn, the environment default ReplicaConsistencyPolicy is enforced rather than the policy specified via TransactionConfig, and this policy is enforced via the openCursorHook rather than the txnBeginHook.

Field Summary

Fields inherited from class com.sleepycat.je.txn.Locker

afterWaiterHook, envImpl, id, lockManager, thread

Constructor Summary

Constructors

Constructor and Description
ReplicaThreadLocker(RepImpl repImpl)

Method Summary

Modifier and Type	Method and Description
void	disallowReplicaWrite() Unconditionally throws ReplicaWriteException because this locker was created on a replica.
LockResult	lockInternal(long lsn, LockType lockType, boolean noWait, boolean jumpAheadOfWaiters, DatabaseImpl database) This overridden method prevents writes on a replica.
ThreadLocker	newEmptyThreadLockerClone()
void	openCursorHook(DatabaseImpl dbImpl) Verifies that consistency requirements are met before allowing the cursor to be opened.
void	preLogWithoutLock(DatabaseImpl database) If logging occurs before locking, we must screen out write locks here.

Methods inherited from class com.sleepycat.je.txn.ThreadLocker

checkPreempted, checkState, createThreadLocker, lockAfterLsnChange, newNonTxnLocker, sharesLocksWith

Methods inherited from class com.sleepycat.je.txn.BasicLocker

addDbCleanup, addLock, collectStats, createBasicLocker, createBasicLocker, generateId, getTxnLocker, getWriteLockInfo, getWriteOwnerLocker, isReadCommittedIsolation, isSerializableIsolation, isTransactional, lockingRequired, nonTxnOperationEnd, operationEnd, registerCursor, releaseNonTxnLocks, unRegisterCursor

Methods inherited from class com.sleepycat.je.txn.Locker

addDeleteInfo, addOpenedDatabase, allowReleaseLockAfterLsnChange, demoteLock, dumpLockTable, getDefaultNoWait, getEnvironment, getId, getImportunate, getInitialLockTimeout, getLockTimeout, getPreemptable, getTransaction, getTxnTimeout, isLocalWrite, isReadOnly, isReadUncommittedDefault, isReplicated, isRolledBack, isTimedOut, isValid, lock, nonBlockingLock, operationEnd, operationEnd, releaseLock, setClosingLocker, setDefaultNoWait, setImportunate, setLockTimeout, setOnlyAbortable, setPreemptable, setPreempted, setTxnTimeout, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ReplicaThreadLocker

public ReplicaThreadLocker(RepImpl repImpl)

Method Detail

newEmptyThreadLockerClone

public ThreadLocker newEmptyThreadLockerClone()

Overrides:

newEmptyThreadLockerClone in class ThreadLocker

lockInternal

public LockResult lockInternal(long lsn,
                               LockType lockType,
                               boolean noWait,
                               boolean jumpAheadOfWaiters,
                               DatabaseImpl database)

This overridden method prevents writes on a replica. This check is redundant because Cursor won't allow writes to a transactional database when no Transaction is specified. But we check here also for safety and for consistency with ReadonlyTxn.

Overrides:

lockInternal in class BasicLocker

Parameters:

lsn - is the node to lock.

lockType - is the type of lock to request.

noWait - is true to override the defaultNoWait setting. If true, or if defaultNoWait is true, throws LockNotAvailableException if the lock cannot be granted without waiting.

jumpAheadOfWaiters - grant the lock before other waiters, if any.

database - is the database containing lsn.

preLogWithoutLock

public void preLogWithoutLock(DatabaseImpl database)

If logging occurs before locking, we must screen out write locks here. If we allow the operation (e.g., for a non-replicated DB), then be sure to call the base class method to prepare to undo in the (very unlikely) event that logging succeeds but locking fails. [#22875]

Overrides:

preLogWithoutLock in class BasicLocker

disallowReplicaWrite

public void disallowReplicaWrite()

Unconditionally throws ReplicaWriteException because this locker was created on a replica.

Overrides:

disallowReplicaWrite in class Locker

openCursorHook

public void openCursorHook(DatabaseImpl dbImpl)
                    throws ReplicaConsistencyException

Verifies that consistency requirements are met before allowing the cursor to be opened.

Overrides:

openCursorHook in class Locker

Throws:

ReplicaConsistencyException