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com.tangosol.io.bdb
Class DatabaseFactory.EnvironmentHolder.DirectoryLock

java.lang.Object
com.tangosol.io.bdb.DatabaseFactory.EnvironmentHolder.DirectoryLock

Enclosing class:

DatabaseFactory.EnvironmentHolder

protected static class DatabaseFactory.EnvironmentHolder.DirectoryLock

extends java.lang.Object

Directory based lock. <p/> A single instance of the DirectoryLock is not intended for inter thread locking. Multiple instance refering to the same File should be used instead.

Field Summary

static java.lang.String	LOCK_FILE_NAME Name of warning file.
protected java.io.File	m_dir Directory to lock.
protected java.io.FileOutputStream	m_fstreamLocked The FileStream which the actuall lock is held on.
protected java.nio.channels.FileLock	m_lockDir The actual FileLock.
protected java.lang.String	m_sLockText Text to include in the lock file.

Constructor Summary

DatabaseFactory.EnvironmentHolder.DirectoryLock(java.io.File dir, java.lang.String sLockText)
Create a DirectoryLock which can be used to try to lock a directory.

Method Summary

protected void	finalize() Automatically release the lock on finalization.
boolean	tryLock() Try to lock the directory.
boolean	tryUnlock() Try to unlock the directory.

Field Detail

LOCK_FILE_NAME

public static final java.lang.String LOCK_FILE_NAME

Name of warning file.

See Also:

Constant Field Values

m_dir

protected java.io.File m_dir

Directory to lock.

m_fstreamLocked

protected java.io.FileOutputStream m_fstreamLocked

The FileStream which the actuall lock is held on.

m_lockDir

protected java.nio.channels.FileLock m_lockDir

The actual FileLock.

m_sLockText

protected java.lang.String m_sLockText

Text to include in the lock file.

Constructor Detail

DatabaseFactory.EnvironmentHolder.DirectoryLock

public DatabaseFactory.EnvironmentHolder.DirectoryLock(java.io.File dir,
                                                       java.lang.String sLockText)

Create a DirectoryLock which can be used to try to lock a directory. The object is created in an unlocked state.

Parameters:

dir - the directory to lock

sLockText - the text to include in the lock file

Method Detail

tryLock

public boolean tryLock()
                throws java.io.IOException

Try to lock the directory.

Returns:

true if a lock is obtained, false if it is locked by another DirectoryLock

Throws:

java.io.IOException - if an IO error occurs while creating the lock file

tryUnlock

public boolean tryUnlock()
                  throws java.io.IOException

Try to unlock the directory.

Returns:

true if a lock is released, false if the directory was not locked by this DirectoryLock

Throws:

java.io.IOException - if an IO error occurs while deleting the lock file, the lock may be left in an unlocked state

finalize

protected void finalize()
                 throws java.lang.Throwable

Automatically release the lock on finalization. <p/> The OS will ensure that the lock is released regardless but this allows the lock file to be deleted as well.

Throws:

java.lang.Throwable

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