de.grogra.util
Class LockableImpl

java.lang.Object
  de.grogra.util.LockableImpl

All Implemented Interfaces:

Lockable

Direct Known Subclasses:

PersistenceManager

public class LockableImpl
extends java.lang.Object
implements Lockable

Nested Class Summary

Nested classes/interfaces inherited from interface de.grogra.util.Lockable

Lockable.DeadLockException

Constructor Summary

LockableImpl()

Method Summary

protected void	enterWriteLock()
void	execute(LockProtectedRunnable task, boolean write) Asynchronously executes a task such that it possesses a lock on this Lockable.
void	execute(LockProtectedRunnable task, Lock retained) Asynchronously executes a task using a lock which has been retained before within another task.
void	executeForcedly(LockProtectedRunnable task, boolean write) Synchronously executes a task such that it possesses a lock on this Lockable.
void	executeForcedly(LockProtectedRunnable task, Lock retained) Synchronously executes a task using a lock which has been retained before within another task.
protected void	executeInAllowedThread(java.lang.Runnable r)
long	getMaxWaitingTime() Returns the waiting time of the pending task which is waiting longest, or -1 if there is no pending task.
int	getQueueLength() Returns the current number of tasks which are waiting for locked execution.
protected void	invokeRun(LockProtectedRunnable task, boolean sync, Lock lock)
protected boolean	isAllowedThread(boolean write)
boolean	isLocked(boolean write) Determines if the current thread has a lock for this Lockable.
protected void	leaveWriteLock()

Methods inherited from class java.lang.Object

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

Constructor Detail

LockableImpl

public LockableImpl()

Method Detail

enterWriteLock

protected void enterWriteLock()

execute

public void execute(LockProtectedRunnable task,
                    boolean write)

Description copied from interface: Lockable

Asynchronously executes a task such that it possesses a lock on this Lockable. Note that the execution is asynchronous, so that the thread in which the task will actually be executed may differ from the current thread.

Specified by:

execute in interface Lockable

Parameters:

task - the task to execute

write - shall a write lock be obtained?

execute

public void execute(LockProtectedRunnable task,
                    Lock retained)

Description copied from interface: Lockable

Asynchronously executes a task using a lock which has been retained before within another task. Note that the execution is asynchronous, so that the thread in which the task will actually be executed may differ from the current thread.

Specified by:

execute in interface Lockable

Parameters:

task - the task to execute

retained - the previously retained lock

See Also:

Lock.retain()

executeForcedly

public void executeForcedly(LockProtectedRunnable task,
                            boolean write)
                     throws java.lang.InterruptedException,
                            Lockable.DeadLockException

Description copied from interface: Lockable

Synchronously executes a task such that it possesses a lock on this Lockable. The execution is performed in the current thread.

Specified by:

executeForcedly in interface Lockable

Parameters:

task - the task to execute

write - shall a write lock be obtained?

Throws:

java.lang.InterruptedException

Lockable.DeadLockException

executeForcedly

public void executeForcedly(LockProtectedRunnable task,
                            Lock retained)
                     throws java.lang.InterruptedException

Description copied from interface: Lockable

Synchronously executes a task using a lock which has been retained before within another task. The execution is performed in the current thread.

Specified by:

executeForcedly in interface Lockable

Parameters:

task - the task to execute

retained - the previously retained lock

Throws:

java.lang.InterruptedException

See Also:

Lock.retain()

executeInAllowedThread

protected void executeInAllowedThread(java.lang.Runnable r)

getMaxWaitingTime

public long getMaxWaitingTime()

Description copied from interface: Lockable

Returns the waiting time of the pending task which is waiting longest, or -1 if there is no pending task.

Specified by:

getMaxWaitingTime in interface Lockable

Returns:

current maximum waiting time of pending tasks

getQueueLength

public int getQueueLength()

Description copied from interface: Lockable

Returns the current number of tasks which are waiting for locked execution.

Specified by:

getQueueLength in interface Lockable

Returns:

current number of waiting tasks

invokeRun

protected void invokeRun(LockProtectedRunnable task,
                         boolean sync,
                         Lock lock)

isAllowedThread

protected boolean isAllowedThread(boolean write)

isLocked

public boolean isLocked(boolean write)

Description copied from interface: Lockable

Determines if the current thread has a lock for this Lockable.

Specified by:

isLocked in interface Lockable

Parameters:

write - check for write locks only (true) or for both read and write locks (false)

Returns:

true if the current thread has a lock

leaveWriteLock

protected void leaveWriteLock()