com.sleepycat.je.txn
Class ReadCommittedLocker

java.lang.Object
  com.sleepycat.je.txn.Locker
      com.sleepycat.je.txn.BasicLocker
          com.sleepycat.je.txn.BuddyLocker
              com.sleepycat.je.txn.ReadCommittedLocker

public class ReadCommittedLocker
extends BuddyLocker

Extends BuddyLocker to acquire write locks using the buddy locker (the transaction locker). This is used for ReadCommitted (Degree 2) isolation.

Field Summary

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

defaultNoWait, deleteInfo, envImpl, handleLockToHandleMap, handleToHandleLockMap, id, lockManager, lockTimeOutMillis, readUncommittedDefault, thread

Constructor Summary

ReadCommittedLocker(EnvironmentImpl env, Locker buddy)
Creates a ReadCommittedLocker.

Method Summary

void	addDeleteInfo(BIN bin, Key deletedKey) Forwards this method to the transactional buddy.
boolean	createdNode(long nodeId) Forwards this method to the transactional buddy.
long	getAbortLsn(long nodeId) Forwards this method to the transactional buddy.
WriteLockInfo	getWriteLockInfo(long nodeId)
boolean	isReadCommittedIsolation() Is always read-committed isolation.
boolean	isTransactional() Is always transactional because the buddy locker is transactional.
(package private) LockResult	lockInternal(long nodeId, LockType lockType, boolean noWait, DatabaseImpl database) Forwards write locks to the buddy locker (the transaction locker).
Locker	newNonTxnLocker() Creates a new instance of this txn for the same environment.
void	registerCursor(CursorImpl cursor) Forwards this method to the transactional buddy.
void	releaseLock(long nodeId) Releases the lock from this locker, or if not owned by this locker then releases it from the buddy locker.
void	unRegisterCursor(CursorImpl cursor) Forwards this method to the transactional buddy.

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

getBuddy, getTxnLocker, releaseNonTxnLocks, sharesLocksWith

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

addLock, checkState, collectStats, generateId, getOwnerAbortLsn, getWriteOwnerLocker, isSerializableIsolation, markDeleteAtTxnEnd, moveWriteToReadLock, operationEnd, operationEnd, removeLock, setHandleLockOwner

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

addToHandleMaps, demoteLock, dumpLockTable, getDefaultNoWait, getId, getLockTimeout, getTxnStartMillis, getTxnTimeOut, getWaitingFor, isHandleLockTransferrable, isReadUncommittedDefault, isTimedOut, lock, nonBlockingLock, operationEnd, rememberHandleWriteLock, setLockTimeout, setOnlyAbortable, setTxnTimeout, setWaitingFor, toString, transferHandleLock, transferHandleLockToHandle, unregisterHandle

Methods inherited from class java.lang.Object

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

Constructor Detail

ReadCommittedLocker

public ReadCommittedLocker(EnvironmentImpl env,
                           Locker buddy)
                    throws DatabaseException

Creates a ReadCommittedLocker.

Parameters:

buddy - is a transactional locker that will be used for acquiring write locks.

Throws:

DatabaseException

Method Detail

newNonTxnLocker

public Locker newNonTxnLocker()
                       throws DatabaseException

Creates a new instance of this txn for the same environment. No transactional locks are held by this object, so no locks are retained. newNonTxnLocker is also called for the BuddyLocker.

Overrides:

newNonTxnLocker in class BuddyLocker

Throws:

DatabaseException

lockInternal

LockResult lockInternal(long nodeId,
                        LockType lockType,
                        boolean noWait,
                        DatabaseImpl database)
                  throws DatabaseException

Forwards write locks to the buddy locker (the transaction locker).

Overrides:

lockInternal in class BasicLocker

Parameters:

nodeId - 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 LockNotGrantedException if the lock cannot be granted without waiting.

database - is the database containing nodeId.

Throws:

DeadlockException - if acquiring a blocking lock would result in a deadlock.

DatabaseException

See Also:

Locker.lockInternal(long, com.sleepycat.je.txn.LockType, boolean, com.sleepycat.je.dbi.DatabaseImpl)

releaseLock

public void releaseLock(long nodeId)
                 throws DatabaseException

Releases the lock from this locker, or if not owned by this locker then releases it from the buddy locker.

Overrides:

releaseLock in class Locker

Throws:

DatabaseException

createdNode

public boolean createdNode(long nodeId)
                    throws DatabaseException

Forwards this method to the transactional buddy. Since the buddy handles write locks, it knows whether this transaction created the node.

Overrides:

createdNode in class BasicLocker

Returns:

true if this transaction created this node, for a operation with transactional semantics.

Throws:

DatabaseException

getAbortLsn

public long getAbortLsn(long nodeId)
                 throws DatabaseException

Forwards this method to the transactional buddy. The buddy handles write locks and therefore handles abort information.

Overrides:

getAbortLsn in class BasicLocker

Returns:

the abort LSN for this node.

Throws:

DatabaseException

getWriteLockInfo

public WriteLockInfo getWriteLockInfo(long nodeId)
                               throws DatabaseException

Overrides:

getWriteLockInfo in class BasicLocker

Returns:

the WriteLockInfo for this node.

Throws:

DatabaseException

addDeleteInfo

public void addDeleteInfo(BIN bin,
                          Key deletedKey)
                   throws DatabaseException

Forwards this method to the transactional buddy. The buddy handles write locks and therefore handles delete information.

Overrides:

addDeleteInfo in class Locker

Throws:

DatabaseException

registerCursor

public void registerCursor(CursorImpl cursor)
                    throws DatabaseException

Forwards this method to the transactional buddy. The buddy Txn tracks cursors.

Overrides:

registerCursor in class BasicLocker

Throws:

DatabaseException

unRegisterCursor

public void unRegisterCursor(CursorImpl cursor)
                      throws DatabaseException

Forwards this method to the transactional buddy. The buddy Txn tracks cursors.

Overrides:

unRegisterCursor in class BasicLocker

Throws:

DatabaseException

isTransactional

public boolean isTransactional()

Is always transactional because the buddy locker is transactional.

Overrides:

isTransactional in class BasicLocker

isReadCommittedIsolation

public boolean isReadCommittedIsolation()

Is always read-committed isolation.

Overrides:

isReadCommittedIsolation in class BasicLocker