com.sleepycat.je.txn

Class LockManager

java.lang.Object

com.sleepycat.je.txn.LockManager

All Implemented Interfaces:

EnvConfigObserver

Direct Known Subclasses:

DummyLockManager, LatchedLockManager, SyncedLockManager

public abstract class LockManager
extends java.lang.Object
implements EnvConfigObserver

LockManager manages locks. Note that locks are counted as taking up part of the JE cache;

Field Summary

Fields

Modifier and Type	Field and Description
protected Latch[]	lockTableLatches
protected int	nLockTables
(package private) static long	TOTAL_LOCKIMPL_OVERHEAD
(package private) static long	TOTAL_THINLOCKIMPL_OVERHEAD

Constructor Summary

Constructors

Constructor and Description
LockManager(EnvironmentImpl envImpl)

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract LockAttemptResult	attemptLock(java.lang.Long nodeId, Locker locker, LockType type, boolean nonBlockingRequest)
protected LockAttemptResult	attemptLockInternal(java.lang.Long nodeId, Locker locker, LockType type, boolean nonBlockingRequest, int lockTableIndex)
(package private) abstract void	demote(long nodeId, Locker locker) Demote a lock from write to read.
protected void	demoteInternal(long nodeId, Locker locker, int lockTableIndex) Do the real work of demote.
void	dump() Debugging
protected abstract void	dumpLockTable(LockStats stats) Dump the lock table to the lock stats.
protected void	dumpLockTableInternal(LockStats stats, int i) Do the real work of dumpLockTableInternal.
java.lang.String	dumpToString()
void	envConfigUpdate(DbConfigManager configMgr, EnvironmentMutableConfig ignore) Process notifications of mutable property changes.
protected int	getLockTableIndex(long nodeId)
protected int	getLockTableIndex(java.lang.Long nodeId)
(package private) abstract Locker	getWriteOwnerLocker(java.lang.Long nodeId)
protected Locker	getWriteOwnerLockerInternal(java.lang.Long nodeId, int lockTableIndex) Do the real work of getWriteOwnerLocker.
(package private) abstract boolean	isLocked(java.lang.Long nodeId) Test the status of the lock on nodeId.
protected boolean	isLockedInternal(java.lang.Long nodeId, int lockTableIndex) Do the real work of isLocked.
(package private) abstract boolean	isOwner(java.lang.Long nodeId, Locker locker, LockType type) Return true if this locker owns this a lock of this type on given node.
protected boolean	isOwnerInternal(java.lang.Long nodeId, Locker locker, LockType type, int lockTableIndex) Do the real work of isOwner.
(package private) abstract boolean	isWaiter(java.lang.Long nodeId, Locker locker) Return true if this locker is waiting on this lock.
protected boolean	isWaiterInternal(java.lang.Long nodeId, Locker locker, int lockTableIndex) Do the real work of isWaiter.
LockGrantType	lock(long nodeId, Locker locker, LockType type, long timeout, boolean nonBlockingRequest, DatabaseImpl database) Attempt to acquire a lock of type on nodeId.
LockStats	lockStat(StatsConfig config) Statistics
protected abstract Lock	lookupLock(java.lang.Long nodeId)
protected Lock	lookupLockInternal(java.lang.Long nodeId, int lockTableIndex)
protected abstract DeadlockException	makeTimeoutMsg(java.lang.String lockOrTxn, Locker locker, long nodeId, LockType type, LockGrantType grantType, Lock useLock, long timeout, long start, long now, DatabaseImpl database) Create a informative lock or txn timeout message.
protected DeadlockException	makeTimeoutMsgInternal(java.lang.String lockOrTxn, Locker locker, long nodeId, LockType type, LockGrantType grantType, Lock useLock, long timeout, long start, long now, DatabaseImpl database) Do the real work of creating an lock or txn timeout message.
(package private) abstract int	nOwners(java.lang.Long nodeId) Return the number of owners of this lock.
protected int	nOwnersInternal(java.lang.Long nodeId, int lockTableIndex) Do the real work of nWaiters.
(package private) abstract int	nWaiters(java.lang.Long nodeId) Return the number of waiters for this lock.
protected int	nWaitersInternal(java.lang.Long nodeId, int lockTableIndex) Do the real work of nWaiters.
boolean	release(long nodeId, Locker locker) Release a lock and possibly notify any waiters that they have been granted the lock.
protected abstract java.util.Set<Locker>	releaseAndFindNotifyTargets(long nodeId, Locker locker) Release the lock, and return the set of new owners to notify, if any.
protected java.util.Set<Locker>	releaseAndFindNotifyTargetsInternal(long nodeId, Locker locker, int lockTableIndex) Do the real work of releaseAndFindNotifyTargets
(package private) static void	setLockTableDump(boolean enable) Called when the je.txn.dumpLocks property is changed.
(package private) abstract void	transfer(long nodeId, Locker owningLocker, Locker destLocker, boolean demoteToRead) Transfer ownership a lock from one locker to another locker.
protected void	transferInternal(long nodeId, Locker owningLocker, Locker destLocker, boolean demoteToRead, int lockTableIndex) Do the real work of transfer
(package private) abstract void	transferMultiple(long nodeId, Locker owningLocker, Locker[] destLockers) Transfer ownership a lock from one locker to a set of other txns, cloning the lock as necessary.
protected void	transferMultipleInternal(long nodeId, Locker owningLocker, Locker[] destLockers, int lockTableIndex) Do the real work of transferMultiple
protected abstract boolean	validateOwnership(java.lang.Long nodeId, Locker locker, LockType type, boolean flushFromWaiters, MemoryBudget mb)
protected boolean	validateOwnershipInternal(java.lang.Long nodeId, Locker locker, LockType type, boolean flushFromWaiters, MemoryBudget mb, int lockTableIndex)

Methods inherited from class java.lang.Object

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

Field Detail

TOTAL_LOCKIMPL_OVERHEAD

static final long TOTAL_LOCKIMPL_OVERHEAD

TOTAL_THINLOCKIMPL_OVERHEAD

static final long TOTAL_THINLOCKIMPL_OVERHEAD

nLockTables

protected int nLockTables

lockTableLatches

protected Latch[] lockTableLatches

Constructor Detail

LockManager

public LockManager(EnvironmentImpl envImpl)
            throws DatabaseException

Throws:

DatabaseException

Method Detail

envConfigUpdate

public void envConfigUpdate(DbConfigManager configMgr,
                   EnvironmentMutableConfig ignore)
                     throws DatabaseException

Process notifications of mutable property changes.

Specified by:

envConfigUpdate in interface EnvConfigObserver

Throws:

DatabaseException

setLockTableDump

static void setLockTableDump(boolean enable)

Called when the je.txn.dumpLocks property is changed.

getLockTableIndex

protected int getLockTableIndex(java.lang.Long nodeId)

getLockTableIndex

protected int getLockTableIndex(long nodeId)

lock

public LockGrantType lock(long nodeId,
                 Locker locker,
                 LockType type,
                 long timeout,
                 boolean nonBlockingRequest,
                 DatabaseImpl database)
                   throws DeadlockException,
                          DatabaseException

Attempt to acquire a lock of type on nodeId. If the lock acquisition would result in a deadlock, throw an exception.
If the requested lock is not currently available, block until it is or until timeout milliseconds have elapsed.
If a lock of type is already held, return EXISTING.
If a WRITE lock is held and a READ lock is requested, return PROMOTION.
If a lock request is for a lock that is not currently held, return either NEW or DENIED depending on whether the lock is granted or not.

Parameters:

nodeId - The NodeId to lock.

locker - The Locker to lock this on behalf of.

type - The lock type requested.

timeout - milliseconds to time out after if lock couldn't be obtained. 0 means block indefinitely. Not used if nonBlockingRequest is true.

nonBlockingRequest - if true, means don't block if lock can't be acquired, and ignore the timeout parameter.

Returns:

a LockGrantType indicating whether the request was fulfilled or not. LockGrantType.NEW means the lock grant was fulfilled and the caller did not previously hold the lock. PROMOTION means the lock was granted and it was a promotion from READ to WRITE. EXISTING means the lock was already granted (not a promotion). DENIED means the lock was not granted either because the timeout passed without acquiring the lock or timeout was -1 and the lock was not immediately available.

Throws:

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

DatabaseException

lookupLock

protected abstract Lock lookupLock(java.lang.Long nodeId)
                            throws DatabaseException

Throws:

DatabaseException

lookupLockInternal

protected Lock lookupLockInternal(java.lang.Long nodeId,
                      int lockTableIndex)
                           throws DatabaseException

Throws:

DatabaseException

attemptLock

protected abstract LockAttemptResult attemptLock(java.lang.Long nodeId,
                            Locker locker,
                            LockType type,
                            boolean nonBlockingRequest)
                                          throws DatabaseException

Throws:

DatabaseException

attemptLockInternal

protected LockAttemptResult attemptLockInternal(java.lang.Long nodeId,
                                    Locker locker,
                                    LockType type,
                                    boolean nonBlockingRequest,
                                    int lockTableIndex)
                                         throws DatabaseException

Throws:

DatabaseException

makeTimeoutMsg

protected abstract DeadlockException makeTimeoutMsg(java.lang.String lockOrTxn,
                               Locker locker,
                               long nodeId,
                               LockType type,
                               LockGrantType grantType,
                               Lock useLock,
                               long timeout,
                               long start,
                               long now,
                               DatabaseImpl database)
                                             throws DatabaseException

Create a informative lock or txn timeout message.

Throws:

DatabaseException

makeTimeoutMsgInternal

protected DeadlockException makeTimeoutMsgInternal(java.lang.String lockOrTxn,
                                       Locker locker,
                                       long nodeId,
                                       LockType type,
                                       LockGrantType grantType,
                                       Lock useLock,
                                       long timeout,
                                       long start,
                                       long now,
                                       DatabaseImpl database)

Do the real work of creating an lock or txn timeout message.

release

public boolean release(long nodeId,
              Locker locker)
                throws DatabaseException

Release a lock and possibly notify any waiters that they have been granted the lock.

Parameters:

nodeId - The node ID of the lock to release.

Returns:

true if the lock is released successfully, false if the lock is not currently being held.

Throws:

DatabaseException

releaseAndFindNotifyTargets

protected abstract java.util.Set<Locker> releaseAndFindNotifyTargets(long nodeId,
                                                Locker locker)
                                                              throws DatabaseException

Release the lock, and return the set of new owners to notify, if any.

Returns:

null if the lock does not exist or the given locker was not the owner, a non-empty set if owners should be notified after releasing, an empty set if no notification is required.

Throws:

DatabaseException

releaseAndFindNotifyTargetsInternal

protected java.util.Set<Locker> releaseAndFindNotifyTargetsInternal(long nodeId,
                                                        Locker locker,
                                                        int lockTableIndex)
                                                             throws DatabaseException

Do the real work of releaseAndFindNotifyTargets

Throws:

DatabaseException

transfer

abstract void transfer(long nodeId,
            Locker owningLocker,
            Locker destLocker,
            boolean demoteToRead)
                throws DatabaseException

Transfer ownership a lock from one locker to another locker. We're not sending any notification to the waiters on the lock table, and the past and present owner should be ready for the transfer.

Throws:

DatabaseException

transferInternal

protected void transferInternal(long nodeId,
                    Locker owningLocker,
                    Locker destLocker,
                    boolean demoteToRead,
                    int lockTableIndex)
                         throws DatabaseException

Do the real work of transfer

Throws:

DatabaseException

transferMultiple

abstract void transferMultiple(long nodeId,
                    Locker owningLocker,
                    Locker[] destLockers)
                        throws DatabaseException

Transfer ownership a lock from one locker to a set of other txns, cloning the lock as necessary. This will always be demoted to read, as we can't have multiple locker owners any other way. We're not sending any notification to the waiters on the lock table, and the past and present owners should be ready for the transfer.

Throws:

DatabaseException

transferMultipleInternal

protected void transferMultipleInternal(long nodeId,
                            Locker owningLocker,
                            Locker[] destLockers,
                            int lockTableIndex)
                                 throws DatabaseException

Do the real work of transferMultiple

Throws:

DatabaseException

demote

abstract void demote(long nodeId,
          Locker locker)
              throws DatabaseException

Demote a lock from write to read. Call back to the owning locker to move this to its read collection.

Parameters:

lock - The lock to release. If null, use nodeId to find lock

locker -

Throws:

DatabaseException

demoteInternal

protected void demoteInternal(long nodeId,
                  Locker locker,
                  int lockTableIndex)
                       throws DatabaseException

Do the real work of demote.

Throws:

DatabaseException

isLocked

abstract boolean isLocked(java.lang.Long nodeId)
                   throws DatabaseException

Test the status of the lock on nodeId. If any transaction holds any lock on it, true is returned. If no transaction holds a lock on it, false is returned. This method is only used by unit tests.

Parameters:

nodeId - The NodeId to check.

Returns:

true if any transaction holds any lock on the nodeid. false if no lock is held by any transaction.

Throws:

DatabaseException

isLockedInternal

protected boolean isLockedInternal(java.lang.Long nodeId,
                       int lockTableIndex)

Do the real work of isLocked.

isOwner

abstract boolean isOwner(java.lang.Long nodeId,
              Locker locker,
              LockType type)
                  throws DatabaseException

Return true if this locker owns this a lock of this type on given node. This method is only used by unit tests.

Throws:

DatabaseException

isOwnerInternal

protected boolean isOwnerInternal(java.lang.Long nodeId,
                      Locker locker,
                      LockType type,
                      int lockTableIndex)

Do the real work of isOwner.

isWaiter

abstract boolean isWaiter(java.lang.Long nodeId,
               Locker locker)
                   throws DatabaseException

Return true if this locker is waiting on this lock. This method is only used by unit tests.

Throws:

DatabaseException

isWaiterInternal

protected boolean isWaiterInternal(java.lang.Long nodeId,
                       Locker locker,
                       int lockTableIndex)

Do the real work of isWaiter.

nWaiters

abstract int nWaiters(java.lang.Long nodeId)
               throws DatabaseException

Return the number of waiters for this lock.

Throws:

DatabaseException

nWaitersInternal

protected int nWaitersInternal(java.lang.Long nodeId,
                   int lockTableIndex)

Do the real work of nWaiters.

nOwners

abstract int nOwners(java.lang.Long nodeId)
              throws DatabaseException

Return the number of owners of this lock.

Throws:

DatabaseException

nOwnersInternal

protected int nOwnersInternal(java.lang.Long nodeId,
                  int lockTableIndex)

Do the real work of nWaiters.

getWriteOwnerLocker

abstract Locker getWriteOwnerLocker(java.lang.Long nodeId)
                             throws DatabaseException

Returns:

the transaction that owns the write lock for this

Throws:

DatabaseException

getWriteOwnerLockerInternal

protected Locker getWriteOwnerLockerInternal(java.lang.Long nodeId,
                                 int lockTableIndex)
                                      throws DatabaseException

Do the real work of getWriteOwnerLocker.

Throws:

DatabaseException

validateOwnership

protected abstract boolean validateOwnership(java.lang.Long nodeId,
                        Locker locker,
                        LockType type,
                        boolean flushFromWaiters,
                        MemoryBudget mb)
                                      throws DatabaseException

Throws:

DatabaseException

validateOwnershipInternal

protected boolean validateOwnershipInternal(java.lang.Long nodeId,
                                Locker locker,
                                LockType type,
                                boolean flushFromWaiters,
                                MemoryBudget mb,
                                int lockTableIndex)
                                     throws DatabaseException

Throws:

DatabaseException

lockStat

public LockStats lockStat(StatsConfig config)
                   throws DatabaseException

Statistics

Throws:

DatabaseException

dumpLockTable

protected abstract void dumpLockTable(LockStats stats)
                               throws DatabaseException

Dump the lock table to the lock stats.

Throws:

DatabaseException

dumpLockTableInternal

protected void dumpLockTableInternal(LockStats stats,
                         int i)

Do the real work of dumpLockTableInternal.

dump

public void dump()
          throws DatabaseException

Debugging

Throws:

DatabaseException

dumpToString

public java.lang.String dumpToString()
                              throws DatabaseException

Throws:

DatabaseException