org.modeshape.jcr.value.binary
Class NamedLocks

java.lang.Object
  org.modeshape.jcr.value.binary.NamedLocks

public class NamedLocks
extends Object

A utility class that represents a set of named locks, allowing callers to atomically obtain a lock with a given name. Locks are released as normal. This class uses reference counts to remove locks only when a named lock is no longer being used.

Nested Class Summary

protected class	NamedLocks.NamedLock
protected static class	NamedLocks.WrappedLock

Constructor Summary

NamedLocks()

Method Summary

protected Lock	lock(String name, boolean writeLock)
Lock	readLock(String name) Obtain a read lock for the supplied name.
int	size() Get the number of named locks.
protected void	unlock(NamedLocks.NamedLock namedLock, Lock rawLock)
Lock	writeLock(String name) Obtain a write lock for the supplied name.

Methods inherited from class java.lang.Object

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

Constructor Detail

NamedLocks

public NamedLocks()

Method Detail

writeLock

public Lock writeLock(String name)

Obtain a write lock for the supplied name. When this method returns, the current thread will have obtained the lock. Therefore, there is no need to call any of the lock methods (e.g., NamedLocks.WrappedLock.lock(), NamedLocks.WrappedLock.lockInterruptibly(), NamedLocks.WrappedLock.tryLock() or NamedLocks.WrappedLock.tryLock(long, TimeUnit)), as those methods will immediately return.

Parameters:

name - the name of the lock

Returns:

the lock held by the current thread; never null

readLock

public Lock readLock(String name)

Obtain a read lock for the supplied name. When this method returns, the current thread will have obtained the lock. Therefore, there is no need to call any of the lock methods (e.g., NamedLocks.WrappedLock.lock(), NamedLocks.WrappedLock.lockInterruptibly(), NamedLocks.WrappedLock.tryLock() or NamedLocks.WrappedLock.tryLock(long, TimeUnit)), as those methods will immediately return.

Parameters:

name - the name of the lock

Returns:

the lock held by the current thread; never null

lock

protected final Lock lock(String name,
                          boolean writeLock)

unlock

protected void unlock(NamedLocks.NamedLock namedLock,
                      Lock rawLock)

size

public int size()

Get the number of named locks.

Returns:

the number of named locks; never negative