locklib

Class LockGrant<LockType>

java.lang.Object

locklib.LockGrant<LockType>

Type Parameters:

LockType - type of lock

public class LockGrant<LockType>
extends Object

A lock grant represents the successful acquisition of a lock. Lock grants can be either valid or invalid. They are created valid but, once the lock is released, they become invalid (meaning the lock granted has been revoked).

Lock grants are organized in chains: the previous lock in a chain is called the predecessor lock and the next lock in the chain is called the successor lock. The first lock in the chain has no predecessor and the last has no successor. Chains are built from the target hierarchy: beginning of the chain is the top element in the target hierarchy and the last element in the lock chain is placed in the bottom element locked in target hierarchy.

When being acquired, predecessor locks must be acquired before and released after. This is handled transparently by locklib.

Lock grants are acquired through LockGrantFuture.

Synchronization locks on LockGrant should never be made outside locklib

.

Method Summary

Modifier and Type	Method and Description
void	release() Releases the grant.
LockRequest<LockType>	request() Obtains the lock request that generated this grant.
Target<LockType>	target() Obtains the locked target.
String	toString()
boolean	valid() Checks whether this grant is still valid or not.

Methods inherited from class java.lang.Object

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

Method Detail

valid

public boolean valid()

Checks whether this grant is still valid or not.

Returns:

is the grant still valid?

request

public LockRequest<LockType> request()

Obtains the lock request that generated this grant.

Returns:

the request

target

public Target<LockType> target()

Obtains the locked target.

Returns:

the target

release

public void release()

Releases the grant. This is equivalent to invoke the Target.unlock(LockGrant) method of this grant's target.

toString

public String toString()

Overrides:

toString in class Object