alluxio.master

Class AbstractPrimarySelector

java.lang.Object

alluxio.master.AbstractPrimarySelector

All Implemented Interfaces:

PrimarySelector

Direct Known Subclasses:

RaftPrimarySelector, UfsJournalMultiMasterPrimarySelector, UfsJournalSingleMasterPrimarySelector

@ThreadSafe
public abstract class AbstractPrimarySelector
extends Object
implements PrimarySelector

Base class for implementing primary selectors. This class handles the synchronization logic of getting the current state, waiting for a certain state, or registering a state change listener. Subclasses just need to call setState(NodeState) when they detect a state change. The selector starts off in STANDBY state.

Nested Class Summary

Nested classes/interfaces inherited from interface alluxio.master.PrimarySelector

PrimarySelector.Factory

Constructor Summary

Constructors

Constructor and Description
AbstractPrimarySelector()

Method Summary

Modifier and Type	Method and Description
NodeState	getState()
NodeState	getStateUnsafe()
Scoped	onStateChange(java.util.function.Consumer<NodeState> listener) Registers a listener to be executed whenever the selector's state updates.
protected void	setState(NodeState state)
void	waitForState(NodeState state) Blocks until the primary selector enters the specified state.

Methods inherited from class java.lang.Object

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

Methods inherited from interface alluxio.master.PrimarySelector

start, stop

Constructor Detail

AbstractPrimarySelector

public AbstractPrimarySelector()

Method Detail

setState

protected final void setState(NodeState state)

getState

public final NodeState getState()

Specified by:

getState in interface PrimarySelector

Returns:

the current state

getStateUnsafe

public final NodeState getStateUnsafe()

Specified by:

getStateUnsafe in interface PrimarySelector

Returns:

the current state without the lock acquired

onStateChange

public final Scoped onStateChange(java.util.function.Consumer<NodeState> listener)

Description copied from interface: PrimarySelector

Registers a listener to be executed whenever the selector's state updates. The listener will be executed synchronously in the state update thread, so it should run quickly.

Specified by:

onStateChange in interface PrimarySelector

Parameters:

listener - the listener

Returns:

an object which will unregister the listener when closed

waitForState

public final void waitForState(NodeState state)
                        throws InterruptedException

Description copied from interface: PrimarySelector

Blocks until the primary selector enters the specified state.

Specified by:

waitForState in interface PrimarySelector

Parameters:

state - the state to wait for

Throws:

InterruptedException