de.grogra.util

Interface Lock

public interface Lock

A Lock on a Lockable resource is either a read lock or an exclusive write lock. It is acquired indirectly by one of the execute methods in Lockable.

Author:

Ole Kniemeyer

Method Summary

Methods

Modifier and Type	Method and Description
void	executeWithoutWriteLock(java.lang.Runnable callback) Executes callback while temporarily reducing this write lock to a read lock.
Lockable	getLockable() Returns the resource on which this lock is held.
boolean	isWriteLock() Returns the type of lock.
void	retain() A lock may be retained by invocation of this method within the LockProtectedRunnable.run(boolean, Lock) method of a task.

Method Detail

executeWithoutWriteLock

void executeWithoutWriteLock(java.lang.Runnable callback)
                             throws java.lang.InterruptedException

Executes callback while temporarily reducing this write lock to a read lock. This gives threads waiting for a read lock the chance to execute.

Throws:

java.lang.IllegalStateException - if this lock is not a write lock

java.lang.InterruptedException - if this thread is interrupted while reacquiring the write lock. In this case the lock stays a read lock

getLockable

Lockable getLockable()

Returns the resource on which this lock is held.

Returns:

resource locked by this lock

isWriteLock

boolean isWriteLock()

Returns the type of lock.

Returns:

is this lock a read or write lock?

retain

void retain()

A lock may be retained by invocation of this method within the LockProtectedRunnable.run(boolean, Lock) method of a task. In this case, the lock is not released after the task has been finished: The lock remains active and has to be passed to one of the execute methods in Lockable which take a lock as parameter, only then the lock will be released.