com.hazelcast.concurrent.semaphore

Class SemaphoreService

java.lang.Object

com.hazelcast.concurrent.semaphore.SemaphoreService

All Implemented Interfaces:

ClientAwareService, ManagedService, MembershipAwareService, MigrationAwareService, QuorumAwareService, RemoteService

public class SemaphoreService
extends Object
implements ManagedService, MigrationAwareService, MembershipAwareService, RemoteService, ClientAwareService, QuorumAwareService

Field Summary

Fields

Modifier and Type	Field and Description
static String	SERVICE_NAME

Constructor Summary

Constructors

Constructor and Description
SemaphoreService(NodeEngine nodeEngine)

Method Summary

Modifier and Type	Method and Description
void	beforeMigration(PartitionMigrationEvent partitionMigrationEvent) Called before migration process starts, on both source and destination members.
void	clientDisconnected(String clientUuid) Invoked when a client disconnects from a member.
void	commitMigration(PartitionMigrationEvent event) Commits the migration process for this service, on both source and destination members.
boolean	containsSemaphore(String name)
SemaphoreProxy	createDistributedObject(String objectId) Creates a distributed object.
void	destroyDistributedObject(String objectId) Destroys a distributed object.
String	getQuorumName(String name) Gets the name of the quorum associated with specified operation name.
SemaphoreContainer	getSemaphoreContainer(String name)
void	init(NodeEngine nodeEngine, Properties properties) Initializes this service.
void	insertMigrationData(Map<String,SemaphoreContainer> migrationData)
void	memberAdded(MembershipServiceEvent event) Invoked when a new member is added to the cluster.
void	memberAttributeChanged(MemberAttributeServiceEvent event) Invoked when a member attribute is changed.
void	memberRemoved(MembershipServiceEvent event) Invoked when an existing member leaves the cluster.
Operation	prepareReplicationOperation(PartitionReplicationEvent event) Returns an operation to replicate service data and/or state for a specific partition replica on another cluster member.
void	reset() Resets this service back to its initial state.
void	rollbackMigration(PartitionMigrationEvent event) Rollback the migration process for this service, on both source and destination members.
void	shutdown(boolean terminate) Shuts down this service.

Methods inherited from class java.lang.Object

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

Field Detail

SERVICE_NAME

public static final String SERVICE_NAME

See Also:

Constant Field Values

Constructor Detail

SemaphoreService

public SemaphoreService(NodeEngine nodeEngine)

Method Detail

getSemaphoreContainer

public SemaphoreContainer getSemaphoreContainer(String name)

containsSemaphore

public boolean containsSemaphore(String name)

init

public void init(NodeEngine nodeEngine,
                 Properties properties)

Description copied from interface: ManagedService

Initializes this service.

Specified by:

init in interface ManagedService

Parameters:

nodeEngine - the NodeEngine that this service belongs to

properties - the Properties (can be used to pass settings to the service)

reset

public void reset()

Description copied from interface: ManagedService

Resets this service back to its initial state.

TODO: what is the purpose of reset

Specified by:

reset in interface ManagedService

shutdown

public void shutdown(boolean terminate)

Description copied from interface: ManagedService

Shuts down this service.

TODO: what is the purpose of the terminate variable

Specified by:

shutdown in interface ManagedService

Parameters:

terminate - true to shut down this service

memberAdded

public void memberAdded(MembershipServiceEvent event)

Description copied from interface: MembershipAwareService

Invoked when a new member is added to the cluster. Should be non-blocking.

Specified by:

memberAdded in interface MembershipAwareService

Parameters:

event - the event for a new member added to the cluster

memberRemoved

public void memberRemoved(MembershipServiceEvent event)

Description copied from interface: MembershipAwareService

Invoked when an existing member leaves the cluster. Should be non-blocking.

Specified by:

memberRemoved in interface MembershipAwareService

Parameters:

event - the event for an existing member leaving the cluster

memberAttributeChanged

public void memberAttributeChanged(MemberAttributeServiceEvent event)

Description copied from interface: MembershipAwareService

Invoked when a member attribute is changed.

Specified by:

memberAttributeChanged in interface MembershipAwareService

Parameters:

event - the event for a member attribute being changed

createDistributedObject

public SemaphoreProxy createDistributedObject(String objectId)

Description copied from interface: RemoteService

Creates a distributed object.

Specified by:

createDistributedObject in interface RemoteService

Parameters:

objectId - the name for the created distributed object

Returns:

the created distributed object

destroyDistributedObject

public void destroyDistributedObject(String objectId)

Description copied from interface: RemoteService

Destroys a distributed object.

Specified by:

destroyDistributedObject in interface RemoteService

Parameters:

objectId - the name of the distributed object to destroy

beforeMigration

public void beforeMigration(PartitionMigrationEvent partitionMigrationEvent)

Description copied from interface: MigrationAwareService

Called before migration process starts, on both source and destination members.

Service can take actions required before migration. Migration process will block until this method returns. If this method fails by throwing an exception, migration process for specific partition will fail and will be rolled back.

Specified by:

beforeMigration in interface MigrationAwareService

Parameters:

partitionMigrationEvent - migration event

prepareReplicationOperation

public Operation prepareReplicationOperation(PartitionReplicationEvent event)

Description copied from interface: MigrationAwareService

Returns an operation to replicate service data and/or state for a specific partition replica on another cluster member.

This method will be called on source member whenever partitioning system requires to copy/replicate a partition replica. Returned operation will be executed on destination member. If operation fails by throwing exception, migration process will fail and will be rolled back.

Returning null is allowed and means service does not have anything to replicate.

Specified by:

prepareReplicationOperation in interface MigrationAwareService

Parameters:

event - replication

Returns:

replication operation or null if nothing will be replicated

insertMigrationData

public void insertMigrationData(Map<String,SemaphoreContainer> migrationData)

commitMigration

public void commitMigration(PartitionMigrationEvent event)

Description copied from interface: MigrationAwareService

Commits the migration process for this service, on both source and destination members. This method will be called after all replication operations are executed successfully on destination and master member receives success response from all participants.

Commit is not expected to fail at this point, all exceptions will be suppressed and logged. Implementations of this method must be thread safe as this method may be called concurrently for different migrations on different partitions.

Specified by:

commitMigration in interface MigrationAwareService

Parameters:

event - migration event

rollbackMigration

public void rollbackMigration(PartitionMigrationEvent event)

Description copied from interface: MigrationAwareService

Rollback the migration process for this service, on both source and destination members. This method will be called when migration process fails at any moment. Reasons for failure may be an exception thrown on any migration step or failure(s) of any of the migration participants; either master or source or destination.

Rollback is not expected to fail at this point, all exceptions will be suppressed and logged. Implementations of this method must be thread safe as this method may be called concurrently for different migrations on different partitions.

Specified by:

rollbackMigration in interface MigrationAwareService

Parameters:

event - migration event

clientDisconnected

public void clientDisconnected(String clientUuid)

Description copied from interface: ClientAwareService

Invoked when a client disconnects from a member.

Specified by:

clientDisconnected in interface ClientAwareService

Parameters:

clientUuid - the UUID of the client that disconnected from a member

getQuorumName

public String getQuorumName(String name)

Description copied from interface: QuorumAwareService

Gets the name of the quorum associated with specified operation name.

Specified by:

getQuorumName in interface QuorumAwareService

Parameters:

name - the operation name for which the quorum name is retured

Returns:

name of the associated quorum, null if there is no associated quorum