org.apache.hadoop.hive.metastore.txn.jdbc.functions

Class EnqueueLockFunction

java.lang.Object

org.apache.hadoop.hive.metastore.txn.jdbc.functions.EnqueueLockFunction

All Implemented Interfaces:

TransactionalFunction<Long>

public class EnqueueLockFunction
extends Object
implements TransactionalFunction<Long>

Constructor Summary

Constructors

Constructor and Description
EnqueueLockFunction(LockRequest lockRequest)

Method Summary

Modifier and Type	Method and Description
Long	execute(MultiDataSourceJdbcResource jdbcResource) This enters locks into the queue in LockInfo.LOCK_WAITING mode.

Methods inherited from class java.lang.Object

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

Constructor Detail

EnqueueLockFunction

public EnqueueLockFunction(LockRequest lockRequest)

Method Detail

execute

public Long execute(MultiDataSourceJdbcResource jdbcResource)
             throws MetaException,
                    TxnAbortedException,
                    NoSuchTxnException

This enters locks into the queue in LockInfo.LOCK_WAITING mode. Isolation Level Notes: 1. We use S4U (withe read_committed) to generate the next (ext) lock id. This serializes any 2 enqueueLockWithRetry() calls. 2. We use S4U on the relevant TXNS row to block any concurrent abort/commit/etc. operations

Specified by:

execute in interface TransactionalFunction<Long>

Parameters:

jdbcResource - A MultiDataSourceJdbcResource instance responsible for providing all the necessary resources to be able to perform transactional database calls.

Returns:

Returns with the result of the function call.

Throws:

MetaException - Thrown in case of application error within the function

TxnAbortedException

NoSuchTxnException

See Also:

TxnLockManager.checkLock(long, long, boolean, boolean)