Package net.adoptopenjdk.icedteaweb.lockingfile

Class LockableFile

java.lang.Object

net.adoptopenjdk.icedteaweb.lockingfile.LockableFile

public class LockableFile
extends java.lang.Object

Process & thread lockable access to a file. Creates file if it does not already exist.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static interface	LockableFile.InterProcessLock	Interface for abstracting away the details of how a file is locked system wide.
private class	LockableFile.LockFile	This is an alternative approach to locking a file system-wide.
private class	LockableFile.NioFileLock	This is the recommended way to lock a file system wide (across multiple processes).

Field Summary

Fields

Modifier and Type	Field	Description
private java.io.File	file
private static java.util.Map<java.io.File,LockableFile>	instanceCache
private static Logger	logger
private LockableFile.InterProcessLock	processLock
private boolean	readOnly
private java.util.concurrent.locks.ReentrantLock	threadLock

Constructor Summary

Constructors

Modifier	Constructor	Description
private	LockableFile(java.io.File file)

Method Summary

Modifier and Type	Method	Description
private boolean	canWriteFile(java.io.File file)
private boolean	canWriteParent(java.io.File file)
private void	createFileIfMissing()
private void	createLockableFile()
private void	createParentDirIfMissing(java.io.File f)
java.io.File	getFile()	Get the file being locked.
static LockableFile	getInstance(java.io.File file)	Get a LockableFile for a given File.
boolean	isHeldByCurrentThread()
boolean	isReadOnly()
private boolean	isReadOnly(java.io.File file)
void	lock()	Lock access to the file.Lock is reentrant.
boolean	tryLock()
void	unlock()	Unlock access to the file.Lock is reentrant.

Methods inherited from class java.lang.Object

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

Field Detail

logger

private static final Logger logger

instanceCache

private static final java.util.Map<java.io.File,LockableFile> instanceCache

file

private final java.io.File file

readOnly

private final boolean readOnly

threadLock

private final java.util.concurrent.locks.ReentrantLock threadLock

processLock

private final LockableFile.InterProcessLock processLock

Constructor Detail

LockableFile

private LockableFile(java.io.File file)

Method Detail

getInstance

public static LockableFile getInstance(java.io.File file)

Get a LockableFile for a given File. Ensures that we share the same instance for all threads.

Parameters:

file - the file to lock

Returns:

a LockableFile instance

isReadOnly

private boolean isReadOnly(java.io.File file)

canWriteFile

private boolean canWriteFile(java.io.File file)

canWriteParent

private boolean canWriteParent(java.io.File file)

createParentDirIfMissing

private void createParentDirIfMissing(java.io.File f)

createLockableFile

private void createLockableFile()

getFile

public java.io.File getFile()

Get the file being locked.

Returns:

the file

isReadOnly

public boolean isReadOnly()

Returns:

if the file is read only.

lock

public void lock()
          throws java.io.IOException

Lock access to the file.Lock is reentrant.

Throws:

java.io.IOException - if an I/O error occurs.

tryLock

public boolean tryLock()

createFileIfMissing

private void createFileIfMissing()
                          throws java.io.IOException

Throws:

java.io.IOException

unlock

public void unlock()
            throws java.io.IOException

Unlock access to the file.Lock is reentrant. Does not do anything if not holding the lock.

Throws:

java.io.IOException - if an I/O error occurs.

isHeldByCurrentThread

public boolean isHeldByCurrentThread()