ca.odell.glazedlists.impl.ThreadSafeList Maven / Gradle / Ivy
/* Glazed Lists (c) 2003-2006 */
/* http://publicobject.com/glazedlists/ publicobject.com,*/
/* O'Dell Engineering Ltd.*/
package ca.odell.glazedlists.impl;
import ca.odell.glazedlists.EventList;
import ca.odell.glazedlists.TransformedList;
import ca.odell.glazedlists.event.ListEvent;
import ca.odell.glazedlists.util.concurrent.ReadWriteLock;
import java.util.Collection;
/**
* An {@link EventList} that obtains a {@link ReadWriteLock} for all operations.
*
* This provides some support for sharing {@link EventList}s between multiple
* threads.
*
*
Using a {@link ThreadSafeList} for concurrent access to lists can be expensive
* because a {@link ReadWriteLock} is aquired and released for every operation.
*
*
Warning: Although this class
* provides thread safe access, it does not provide any guarantees that changes
* will not happen between method calls. For example, the following code is unsafe
* because the source {@link EventList} may change between calls to {@link #size() size()}
* and {@link #get(int) get()}:
*
EventList source = ...
* ThreadSafeList myList = new ThreadSafeList(source);
* if(myList.size() > 3) {
* System.out.println(myList.get(3));
* }
*
* Warning: The objects returned
* by {@link #iterator() iterator()}, {@link #subList(int,int) subList()}, etc. are
* not thread safe.
*
* @see ca.odell.glazedlists.util.concurrent
*
* @author Kevin Maltby
*/
public final class ThreadSafeList extends TransformedList {
/**
* Creates a {@link ThreadSafeList} that provides thread safe access to all
* methods in the source {@link EventList}.
*/
public ThreadSafeList(EventList source) {
super(source);
source.addListEventListener(this);
}
/** {@inheritDoc} */
@Override
public void listChanged(ListEvent listChanges) {
// just pass on the changes
updates.forwardEvent(listChanges);
}
/** {@inheritDoc} */
@Override
public E get(int index) {
getReadWriteLock().readLock().lock();
try {
return source.get(index);
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public int size() {
getReadWriteLock().readLock().lock();
try {
return source.size();
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
protected boolean isWritable() {
return true;
}
/** {@inheritDoc} */
@Override
public boolean contains(Object object) {
getReadWriteLock().readLock().lock();
try {
return source.contains(object);
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public boolean containsAll(Collection collection) {
getReadWriteLock().readLock().lock();
try {
return source.containsAll(collection);
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public boolean equals(Object object) {
getReadWriteLock().readLock().lock();
try {
return source.equals(object);
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public int hashCode() {
getReadWriteLock().readLock().lock();
try {
return source.hashCode();
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public int indexOf(Object object) {
getReadWriteLock().readLock().lock();
try {
return source.indexOf(object);
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public int lastIndexOf(Object object) {
getReadWriteLock().readLock().lock();
try {
return source.lastIndexOf(object);
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public boolean isEmpty() {
getReadWriteLock().readLock().lock();
try {
return source.isEmpty();
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public Object[] toArray() {
getReadWriteLock().readLock().lock();
try {
return source.toArray();
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public T[] toArray(T[] array) {
getReadWriteLock().readLock().lock();
try {
return source.toArray(array);
} finally {
getReadWriteLock().readLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public boolean add(E value) {
getReadWriteLock().writeLock().lock();
try {
return source.add(value);
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public boolean remove(Object toRemove) {
getReadWriteLock().writeLock().lock();
try {
return source.remove(toRemove);
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public boolean addAll(Collection values) {
getReadWriteLock().writeLock().lock();
try {
return source.addAll(values);
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public boolean addAll(int index, Collection values) {
getReadWriteLock().writeLock().lock();
try {
return source.addAll(index, values);
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public boolean removeAll(Collection values) {
getReadWriteLock().writeLock().lock();
try {
return source.removeAll(values);
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public boolean retainAll(Collection values) {
getReadWriteLock().writeLock().lock();
try {
return source.retainAll(values);
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public void clear() {
getReadWriteLock().writeLock().lock();
try {
source.clear();
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public E set(int index, E value) {
getReadWriteLock().writeLock().lock();
try {
return source.set(index, value);
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public void add(int index, E value) {
getReadWriteLock().writeLock().lock();
try {
source.add(index, value);
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public E remove(int index) {
getReadWriteLock().writeLock().lock();
try {
return source.remove(index);
} finally {
getReadWriteLock().writeLock().unlock();
}
}
/** {@inheritDoc} */
@Override
public String toString() {
getReadWriteLock().readLock().lock();
try {
return source.toString();
} finally {
getReadWriteLock().readLock().unlock();
}
}
}