org.apache.hadoop.hbase.procedure2

Interface LockStatus

All Known Implementing Classes:

LockAndQueue

@InterfaceAudience.Private
public interface LockStatus

Interface to get status of a Lock without getting access to acquire/release lock. Currently used in MasterProcedureScheduler where we want to give Queues access to lock's status for scheduling purposes, but not the ability to acquire/release it.

Method Summary

Modifier and Type	Method and Description
Procedure<?>	getExclusiveLockOwnerProcedure() Get the procedure which holds the exclusive lock.
default long	getExclusiveLockProcIdOwner() Return the id of the procedure which holds the exclusive lock, if exists.
int	getSharedLockCount() Get the number of procedures which hold the shared lock.
boolean	hasExclusiveLock() Whether the exclusive lock has been held.
boolean	hasLockAccess(Procedure<?> proc) Return true if the procedure itself holds the exclusive lock, or any ancestors of the give procedure hold the exclusive lock.
default boolean	isLocked() Return whether this lock has already been held, Notice that, holding the exclusive lock or shared lock are both considered as locked, i.e, this method usually equals to hasExclusiveLock() || getSharedLockCount() > 0.

Method Detail

isLocked

default boolean isLocked()

Return whether this lock has already been held,

Notice that, holding the exclusive lock or shared lock are both considered as locked, i.e, this method usually equals to hasExclusiveLock() || getSharedLockCount() > 0.

hasExclusiveLock

boolean hasExclusiveLock()

Whether the exclusive lock has been held.

hasLockAccess

boolean hasLockAccess(Procedure<?> proc)

Return true if the procedure itself holds the exclusive lock, or any ancestors of the give procedure hold the exclusive lock.

getExclusiveLockOwnerProcedure

Procedure<?> getExclusiveLockOwnerProcedure()

Get the procedure which holds the exclusive lock.

getExclusiveLockProcIdOwner

default long getExclusiveLockProcIdOwner()

Return the id of the procedure which holds the exclusive lock, if exists. Or a negative value which means no one holds the exclusive lock.

Notice that, in HBase, we assume that the procedure id is positive, or at least non-negative.

getSharedLockCount

int getSharedLockCount()

Get the number of procedures which hold the shared lock.