com.fr.third.jgroups.protocols

类 CENTRAL_LOCK

java.lang.Object

com.fr.third.jgroups.stack.Protocol

com.fr.third.jgroups.protocols.Locking

com.fr.third.jgroups.protocols.CENTRAL_LOCK

所有已实现的接口:

LockNotification

public class CENTRAL_LOCK
extends Locking
implements LockNotification

Implementation of a locking protocol which acquires locks by contacting the coordinator.

Because the coordinator maintains all locks, no total order configuration is required.

CENTRAL_LOCK has all members send lock and unlock requests to a central coordinator. The coordinator has a queue for incoming requests, and grants locks based on order of arrival. To prevent all acquired locks from being forgotten when the coordinator crashes, setting num_backups lets the coordinator backup lock information to a number of backup nodes. Valid values for num_backups are 0 (no backup) to N-1, e.g. in a cluster of 4, we can have only 3 backup nodes.

Say we have a cluster of {A,B,C,D,E} and num_backups=1. A is the coordinator, and A updates all locks (and released locks) in B as well. When A crashes, everybody falls over to B for sending lock and unlock requests. B in turn copies all existing locks over to C and - when locks are acquired or released - forwards this information to C as well.

An alternative is also the PEER_LOCK protocol.

从以下版本开始:

2.12

作者:

Bela Ban

另请参阅:

Locking, PEER_LOCK

嵌套类概要

从类继承的嵌套类/接口 com.fr.third.jgroups.protocols.Locking

Locking.ClientCondition, Locking.ClientLock, Locking.ClientLockTable, Locking.LockingHeader, Locking.Request, Locking.Response, Locking.ServerCondition, Locking.ServerLock, Locking.Type

字段概要

字段

限定符和类型	字段和说明
protected java.util.List<Address>	backups
protected Address	coord
protected boolean	is_coord
protected int	num_backups

从类继承的字段 com.fr.third.jgroups.protocols.Locking

bypass_bundling, client_lock_table, current_lock_id, local_addr, lock_listeners, lock_stripes, lock_striping_size, server_locks, view

从类继承的字段 com.fr.third.jgroups.stack.Protocol

down_prot, ergonomics, id, log, name, stack, stats, up_prot

构造器概要

构造器

构造器和说明
CENTRAL_LOCK()

方法概要

方法

限定符和类型	方法和说明
void	awaited(java.lang.String lock_name, Owner owner)
void	awaiting(java.lang.String lock_name, Owner owner)
protected void	copyLocksTo(java.util.List<Address> new_joiners)
java.lang.String	getBackups()
Address	getCoord()
java.lang.String	getCoordinator()
int	getNumberOfBackups()
void	handleView(View view)
boolean	isCoord()
void	lockCreated(java.lang.String name)
void	lockDeleted(java.lang.String name)
void	locked(java.lang.String lock_name, Owner owner)
protected void	sendAwaitConditionRequest(java.lang.String lock_name, Owner owner)
protected void	sendCreateLockRequest(Address dest, java.lang.String lock_name, Owner owner)
protected void	sendDeleteAwaitConditionRequest(java.lang.String lock_name, Owner owner)
protected void	sendDeleteLockRequest(Address dest, java.lang.String lock_name)
protected void	sendGrantLockRequest(java.lang.String lock_name, int lock_id, Owner owner, long timeout, boolean is_trylock)
protected void	sendReleaseLockRequest(java.lang.String lock_name, Owner owner)
protected void	sendSignalConditionRequest(java.lang.String lock_name, boolean all)
void	setNumberOfBackups(int num_backups)
void	unlocked(java.lang.String lock_name, Owner owner)
protected void	updateBackups(Locking.Type type, java.lang.String lock_name, Owner owner)

从类继承的方法 com.fr.third.jgroups.protocols.Locking

_getLock, addLockListener, createLock, down, getAddress, getBypassBundling, getLock, getLock, getOwner, getView, handleAwaitRequest, handleCreateAwaitingRequest, handleCreateLockRequest, handleDeleteAwaitingRequest, handleDeleteAwaitRequest, handleDeleteLockRequest, handleLockDeniedResponse, handleLockGrantedResponse, handleLockRequest, handleSignalRequest, handleSignalResponse, init, notifyAwaited, notifyAwaiting, notifyLockCreated, notifyLockDeleted, notifyLocked, notifyUnlocked, printLocks, removeLockListener, send, sendLockResponse, sendRequest, sendRequest, sendSignalResponse, setBypassBundling, unlockAll, up

从类继承的方法 com.fr.third.jgroups.stack.Protocol

accept, destroy, dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, isErgonomics, level, parse, printStats, providedDownServices, providedUpServices, requiredDownServices, requiredUpServices, resetStatistics, resetStats, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, setValues, start, statsEnabled, stop, up

从类继承的方法 java.lang.Object

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

字段详细资料

num_backups

protected int num_backups

coord

protected Address coord

is_coord

protected boolean is_coord

backups

protected final java.util.List<Address> backups

构造器详细资料

CENTRAL_LOCK

public CENTRAL_LOCK()

方法详细资料

getCoord

public Address getCoord()

isCoord

public boolean isCoord()

getCoordinator

public java.lang.String getCoordinator()

getNumberOfBackups

public int getNumberOfBackups()

setNumberOfBackups

public void setNumberOfBackups(int num_backups)

getBackups

public java.lang.String getBackups()

sendGrantLockRequest

protected void sendGrantLockRequest(java.lang.String lock_name,
                        int lock_id,
                        Owner owner,
                        long timeout,
                        boolean is_trylock)

指定者:

sendGrantLockRequest 在类中 Locking

sendReleaseLockRequest

protected void sendReleaseLockRequest(java.lang.String lock_name,
                          Owner owner)

指定者:

sendReleaseLockRequest 在类中 Locking

sendCreateLockRequest

protected void sendCreateLockRequest(Address dest,
                         java.lang.String lock_name,
                         Owner owner)

sendDeleteLockRequest

protected void sendDeleteLockRequest(Address dest,
                         java.lang.String lock_name)

sendAwaitConditionRequest

protected void sendAwaitConditionRequest(java.lang.String lock_name,
                             Owner owner)

指定者:

sendAwaitConditionRequest 在类中 Locking

sendSignalConditionRequest

protected void sendSignalConditionRequest(java.lang.String lock_name,
                              boolean all)

指定者:

sendSignalConditionRequest 在类中 Locking

sendDeleteAwaitConditionRequest

protected void sendDeleteAwaitConditionRequest(java.lang.String lock_name,
                                   Owner owner)

指定者:

sendDeleteAwaitConditionRequest 在类中 Locking

handleView

public void handleView(View view)

覆盖:

handleView 在类中 Locking

lockCreated

public void lockCreated(java.lang.String name)

指定者:

lockCreated 在接口中 LockNotification

lockDeleted

public void lockDeleted(java.lang.String name)

指定者:

lockDeleted 在接口中 LockNotification

locked

public void locked(java.lang.String lock_name,
          Owner owner)

指定者:

locked 在接口中 LockNotification

unlocked

public void unlocked(java.lang.String lock_name,
            Owner owner)

指定者:

unlocked 在接口中 LockNotification

awaiting

public void awaiting(java.lang.String lock_name,
            Owner owner)

指定者:

awaiting 在接口中 LockNotification

awaited

public void awaited(java.lang.String lock_name,
           Owner owner)

指定者:

awaited 在接口中 LockNotification

updateBackups

protected void updateBackups(Locking.Type type,
                 java.lang.String lock_name,
                 Owner owner)

copyLocksTo

protected void copyLocksTo(java.util.List<Address> new_joiners)