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.

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.

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