Package org.terracotta.utilities.test.net

Class SystemLevelLocker

java.lang.Object

org.terracotta.utilities.test.net.SystemLevelLocker

class SystemLevelLocker
extends java.lang.Object

Supplies a system-level locking mechanism supporting port management. An instance of this class may be used to coordinate port reservations among multiple JVM instances in a single system.

Field Summary

Fields

Modifier and Type	Field	Description
private java.nio.file.Path	lockFilePath
private static org.slf4j.Logger	LOGGER
private java.nio.channels.FileChannel	openChannel
private int	outstandingLocks
private static java.nio.file.Path	RELATIVE_LOCK_FILE_PATH

Constructor Summary

Constructors

Constructor	Description
SystemLevelLocker()	Creates a new instance of SystemLevelLocker.

Method Summary

Modifier and Type	Method	Description
private void	closeChannelIfUnused()	Closes openChannel if there are no outstanding locks.
(package private) boolean	lock(PortManager.PortRef portRef)	Obtains a system-level lock against the lock file for the identified port.
private void	release(int port, java.nio.channels.FileLock lock)	Release the system-level lock for the specified PortRef instance.

Methods inherited from class java.lang.Object

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

Field Detail

LOGGER

private static final org.slf4j.Logger LOGGER

RELATIVE_LOCK_FILE_PATH

private static final java.nio.file.Path RELATIVE_LOCK_FILE_PATH

lockFilePath

private final java.nio.file.Path lockFilePath

openChannel

private java.nio.channels.FileChannel openChannel

outstandingLocks

private int outstandingLocks

Constructor Detail

SystemLevelLocker

SystemLevelLocker()

Creates a new instance of SystemLevelLocker. This constructor creates or gains access to the common file used for port locking.

The common locking file is not deleted when a SystemLevelLocker instance is discarded. The common locking file persists across uses and is re-used if available.

Throws:

java.lang.IllegalStateException - if the common locking file cannot be created or is otherwise not accessible

Method Detail

lock

boolean lock(PortManager.PortRef portRef)

Obtains a system-level lock against the lock file for the identified port.

Parameters:

portRef - the PortRef identifying the port.

Returns:

true if the system-level lock was obtained; false otherwise

Throws:

java.lang.IllegalStateException - if the lock cannot be obtained because of an IOException

release

private void release(int port,
                     java.nio.channels.FileLock lock)

Release the system-level lock for the specified PortRef instance.

Parameters:

port - the PortRef instance to unlock

lock - the existing FileLock instance

closeChannelIfUnused

private void closeChannelIfUnused()

Closes openChannel if there are no outstanding locks.