com.sleepycat.je.txn

Class BasicLocker

java.lang.Object

com.sleepycat.je.txn.Locker

com.sleepycat.je.txn.BasicLocker

Direct Known Subclasses:

BuddyLocker, HandleLocker, ThreadLocker

public class BasicLocker
extends Locker

A non-transactional Locker that simply tracks locks and releases them when releaseNonTxnLocks or operationEnd is called.

Field Summary

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

afterWaiterHook, envImpl, id, lockManager, thread

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BasicLocker(EnvironmentImpl env) Creates a BasicLocker.
protected	BasicLocker(EnvironmentImpl env, boolean noWait) Creates a BasicLocker with a noWait argument.

Method Summary

Modifier and Type	Method and Description
void	addDbCleanup(DbCleanup cleanup) Database operations like remove, truncate and rename require that DatabaseImpls are deleted or updated at transaction commit or abort.
protected void	addLock(Long lsn, LockType type, LockGrantType grantStatus) Add a lock to set owned by this transaction.
protected void	checkState(boolean ignoreCalledByAbort)
StatGroup	collectStats() Stats.
static BasicLocker	createBasicLocker(EnvironmentImpl env)
static BasicLocker	createBasicLocker(EnvironmentImpl env, boolean noWait)
protected long	generateId(TxnManager txnManager, long ignore) BasicLockers always have a fixed id, because they are never used for recovery.
Txn	getTxnLocker() No transactional locker is available.
WriteLockInfo	getWriteLockInfo(long lsn)
Locker	getWriteOwnerLocker(long lsn) Get the txn that owns the lock on this node.
boolean	isReadCommittedIsolation() Is never read-committed isolation.
boolean	isSerializableIsolation() Is never serializable isolation.
boolean	isTransactional() Is never transactional.
boolean	lockingRequired() Returns true if locking is required for this Locker.
protected LockResult	lockInternal(long lsn, LockType lockType, boolean noWait, boolean jumpAheadOfWaiters, DatabaseImpl database) Abstract method to a blocking or non-blocking lock of the given type on the given LSN.
Locker	newNonTxnLocker() Throws EnvironmentFailureException unconditionally.
void	nonTxnOperationEnd() Release locks and close the cursor at the end of the operation.
void	operationEnd(boolean operationOK) Release locks and close the cursor at the end of the operation.
void	preLogWithoutLock(DatabaseImpl database) In the case where logging occurs before locking, allow lockers to reject the operation (e.g., if writing on a replica) and also prepare to undo in the (very unlikely) event that logging succeeds but locking fails.
void	registerCursor(CursorImpl cursor) This txn doesn't store cursors.
void	releaseNonTxnLocks() Releases all locks, since all locks held by this locker are non-transactional.
void	unRegisterCursor(CursorImpl cursor) This txn doesn't store cursors.

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicLocker

protected BasicLocker(EnvironmentImpl env)

Creates a BasicLocker.

BasicLocker

protected BasicLocker(EnvironmentImpl env,
                      boolean noWait)

Creates a BasicLocker with a noWait argument.

Method Detail

createBasicLocker

public static BasicLocker createBasicLocker(EnvironmentImpl env)
                                     throws DatabaseException

Throws:

DatabaseException

createBasicLocker

public static BasicLocker createBasicLocker(EnvironmentImpl env,
                                            boolean noWait)
                                     throws DatabaseException

Throws:

DatabaseException

generateId

protected long generateId(TxnManager txnManager,
                          long ignore)

BasicLockers always have a fixed id, because they are never used for recovery.

Specified by:

generateId in class Locker

checkState

protected void checkState(boolean ignoreCalledByAbort)

Specified by:

checkState in class Locker

lockInternal

protected LockResult lockInternal(long lsn,
                                  LockType lockType,
                                  boolean noWait,
                                  boolean jumpAheadOfWaiters,
                                  DatabaseImpl database)
                           throws DatabaseException

Description copied from class: Locker

Abstract method to a blocking or non-blocking lock of the given type on the given LSN. Unlike the lock() method, this method does not throw LockNotAvailableException and can therefore be used by nonBlockingLock to probe for a lock without the overhead of an exception stack trace.

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.

Throws:

LockConflictException - if a blocking lock could not be acquired.

DatabaseException

preLogWithoutLock

public void preLogWithoutLock(DatabaseImpl database)

Description copied from class: Locker

In the case where logging occurs before locking, allow lockers to reject the operation (e.g., if writing on a replica) and also prepare to undo in the (very unlikely) event that logging succeeds but locking fails.

Specified by:

preLogWithoutLock in class Locker

getWriteOwnerLocker

public Locker getWriteOwnerLocker(long lsn)
                           throws DatabaseException

Get the txn that owns the lock on this node. Return null if there's no owning txn found.

Throws:

DatabaseException

isTransactional

public boolean isTransactional()

Is never transactional.

Specified by:

isTransactional in class Locker

isSerializableIsolation

public boolean isSerializableIsolation()

Is never serializable isolation.

Specified by:

isSerializableIsolation in class Locker

isReadCommittedIsolation

public boolean isReadCommittedIsolation()

Is never read-committed isolation.

Specified by:

isReadCommittedIsolation in class Locker

getTxnLocker

public Txn getTxnLocker()

No transactional locker is available.

Specified by:

getTxnLocker in class Locker

newNonTxnLocker

public Locker newNonTxnLocker()
                       throws DatabaseException

Throws EnvironmentFailureException unconditionally. If we were to create a new BasicLocker here, it would not share locks with this locker, which violates the definition of this method. This method is not currently called in direct uses of BasicLocker and is overridden by subclasses where it is allowed (e.g., ThreadLocker and ReadCommittedLocker).

Specified by:

newNonTxnLocker in class Locker

Throws:

DatabaseException - from subclasses.

releaseNonTxnLocks

public void releaseNonTxnLocks()
                        throws DatabaseException

Releases all locks, since all locks held by this locker are non-transactional.

Specified by:

releaseNonTxnLocks in class Locker

Throws:

DatabaseException

nonTxnOperationEnd

public void nonTxnOperationEnd()
                        throws DatabaseException

Release locks and close the cursor at the end of the operation.

Specified by:

nonTxnOperationEnd in class Locker

Throws:

DatabaseException

operationEnd

public void operationEnd(boolean operationOK)
                  throws DatabaseException

Release locks and close the cursor at the end of the operation.

Specified by:

operationEnd in class Locker

Parameters:

operationOK - is whether the operation succeeded, since that may impact ending behavior. (i.e for an auto Txn)

Throws:

DatabaseException

registerCursor

public void registerCursor(CursorImpl cursor)

This txn doesn't store cursors.

Specified by:

registerCursor in class Locker

Throws:

DatabaseException - in subclasses.

unRegisterCursor

public void unRegisterCursor(CursorImpl cursor)

This txn doesn't store cursors.

Specified by:

unRegisterCursor in class Locker

lockingRequired

public boolean lockingRequired()

Description copied from class: Locker

Returns true if locking is required for this Locker. All Txnal lockers require it; most BasicLockers do not, but BasicLockers on internal dbs do.

Specified by:

lockingRequired in class Locker

getWriteLockInfo

public WriteLockInfo getWriteLockInfo(long lsn)

Specified by:

getWriteLockInfo in class Locker

Returns:

a dummy WriteLockInfo for this node.

addDbCleanup

public void addDbCleanup(DbCleanup cleanup)

Description copied from class: Locker

Database operations like remove, truncate and rename require that DatabaseImpls are deleted or updated at transaction commit or abort.

Specified by:

addDbCleanup in class Locker

addLock

protected void addLock(Long lsn,
                       LockType type,
                       LockGrantType grantStatus)

Add a lock to set owned by this transaction.

Specified by:

addLock in class Locker

collectStats

public StatGroup collectStats()
                       throws DatabaseException

Stats. Note lack of synchronization while accessing Lock object. Appropriate for unit testing only.

Specified by:

collectStats in class Locker

Throws:

DatabaseException