alluxio.worker.block

Class BlockLockManager

java.lang.Object

alluxio.worker.block.BlockLockManager

@ThreadSafe
public final class BlockLockManager
extends Object

Handle all block locks.

Constructor Summary

Constructors

Constructor and Description
BlockLockManager() Constructs a new BlockLockManager.

Method Summary

Modifier and Type	Method and Description
BlockLock	acquireBlockLock(long sessionId, long blockId, BlockLockType blockLockType) Locks a block.
boolean	checkLock(long sessionId, long blockId, long lockId) Validates the lock is hold by the given session for the given block.
void	cleanupSession(long sessionId) Cleans up the locks currently hold by a specific session.
Set<Long>	getLockedBlocks() Gets a snapshot of currently locked blocks.
Optional<BlockLock>	tryAcquireBlockLock(long sessionId, long blockId, BlockLockType blockLockType, long time, TimeUnit unit) Tries to lock a block within the given time.
void	validate() Checks the internal state of the manager to make sure invariants hold.

Methods inherited from class java.lang.Object

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

Constructor Detail

BlockLockManager

public BlockLockManager()

Constructs a new BlockLockManager.

Method Detail

acquireBlockLock

public BlockLock acquireBlockLock(long sessionId,
                                  long blockId,
                                  BlockLockType blockLockType)

Locks a block. Note that even if this block does not exist, a closable lock is still returned. If all PropertyKey.WORKER_TIERED_STORE_BLOCK_LOCKS are already in use and no lock has been allocated for the specified block, this method will need to wait until a lock can be acquired from the lock pool.

Parameters:

sessionId - the session id

blockId - the block id

blockLockType - BlockLockType.READ or BlockLockType.WRITE

Returns:

closable block lock

tryAcquireBlockLock

public Optional<BlockLock> tryAcquireBlockLock(long sessionId,
                                               long blockId,
                                               BlockLockType blockLockType,
                                               long time,
                                               TimeUnit unit)

Tries to lock a block within the given time. Note that even if this block does not exist, a lock id is still returned. If all PropertyKey.WORKER_TIERED_STORE_BLOCK_LOCKS are already in use and no lock has been allocated for the specified block, this method will need to wait until a lock can be acquired from the lock pool.

Parameters:

sessionId - the session id

blockId - the block id

blockLockType - BlockLockType.READ or BlockLockType.WRITE

time - the maximum time to wait for the lock

unit - the time unit of the time argument

Returns:

lock id or INVALID_LOCK_ID if not able to lock within the given time

checkLock

public boolean checkLock(long sessionId,
                         long blockId,
                         long lockId)

Validates the lock is hold by the given session for the given block.

Parameters:

sessionId - the session id

blockId - the block id

lockId - the lock id

Returns:

hold or not

cleanupSession

public void cleanupSession(long sessionId)

Cleans up the locks currently hold by a specific session.

Parameters:

sessionId - the id of the session to cleanup

getLockedBlocks

public Set<Long> getLockedBlocks()

Gets a snapshot of currently locked blocks.

Returns:

a set of locked blocks

validate

public void validate()

Checks the internal state of the manager to make sure invariants hold. This method is intended for testing purposes. A runtime exception will be thrown if invalid state is encountered. This method should only be called when there are no other concurrent threads accessing this manager.