org.apache.hadoop.hive.metastore.txn

Class DefaultTxnLockManager

java.lang.Object

org.apache.hadoop.hive.metastore.txn.DefaultTxnLockManager

All Implemented Interfaces:

TxnLockManager

public class DefaultTxnLockManager
extends Object
implements TxnLockManager

Constructor Summary

Constructors

Constructor and Description
DefaultTxnLockManager(MultiDataSourceJdbcResource jdbcResource)

Method Summary

Modifier and Type	Method and Description
LockResponse	checkLock(long extLockId, long txnId, boolean zeroWaitReadEnabled, boolean isExclusiveCTAS) Check whether a lock has been obtained.
long	enqueueLock(LockRequest rqst)
ShowLocksResponse	showLocks(ShowLocksRequest rqst) Get information on current locks.
void	unlock(UnlockRequest rqst) Unlock a lock.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultTxnLockManager

public DefaultTxnLockManager(MultiDataSourceJdbcResource jdbcResource)

Method Detail

enqueueLock

public long enqueueLock(LockRequest rqst)
                 throws NoSuchTxnException,
                        TxnAbortedException,
                        MetaException

Specified by:

enqueueLock in interface TxnLockManager

Throws:

NoSuchTxnException

TxnAbortedException

MetaException

checkLock

public LockResponse checkLock(long extLockId,
                              long txnId,
                              boolean zeroWaitReadEnabled,
                              boolean isExclusiveCTAS)
                       throws NoSuchTxnException,
                              NoSuchLockException,
                              TxnAbortedException,
                              MetaException

Description copied from interface: TxnLockManager

Check whether a lock has been obtained. This is used after TxnLockManager.enqueueLock(LockRequest) returned a wait state.

Specified by:

checkLock in interface TxnLockManager

txnId - Transaction id

Returns:

info on the state of the lock

Throws:

NoSuchTxnException

NoSuchLockException

TxnAbortedException

MetaException

unlock

public void unlock(UnlockRequest rqst)
            throws TxnOpenException,
                   MetaException

Description copied from interface: TxnLockManager

Unlock a lock. It is not legal to call this if the caller is part of a txn. In that case the txn should be committed or aborted instead. (Note someday this will change since multi-statement transactions will allow unlocking in the transaction.)

Specified by:

unlock in interface TxnLockManager

Parameters:

rqst - lock to unlock

Throws:

TxnOpenException

MetaException

showLocks

public ShowLocksResponse showLocks(ShowLocksRequest rqst)
                            throws MetaException

Description copied from interface: TxnLockManager

Get information on current locks.

Specified by:

showLocks in interface TxnLockManager

Parameters:

rqst - lock information to retrieve

Returns:

lock information.

Throws:

MetaException