RWCollection.java

// from gee.cs.oswego.edu/home/jsr166/jsr166

package jsr166tests.loops;

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/licenses/publicdomain
 */
import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.locks.*;


/**
 * This is an incomplete implementation of a wrapper class
 * that places read-write locks around unsynchronized Collections.
 * Exists as a sample input for CollectionLoops test.
 */

public final class RWCollection<E> implements Collection<E> {
    private final Collection c;
    private final ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();

    public RWCollection(Collection<E> c) {
        if (c == null)
            throw new NullPointerException();
        this.c = c;
    }

    public RWCollection() {
        this(new ArrayList<E>());
    }

    public final int size() {
        final ReentrantReadWriteLock.ReadLock l =  rwl.readLock();
        l.lock(); try {return c.size();} finally { l.unlock(); }
    }
    public final boolean isEmpty(){
        final ReentrantReadWriteLock.ReadLock l =  rwl.readLock();
        l.lock(); try {return c.isEmpty();} finally { l.unlock(); }
    }

    public final boolean contains(Object o) {
        final ReentrantReadWriteLock.ReadLock l =  rwl.readLock();
        l.lock(); try {return c.contains(o);} finally { l.unlock(); }
    }

    public final boolean equals(Object o) {
        final ReentrantReadWriteLock.ReadLock l =  rwl.readLock();
        l.lock(); try {return c.equals(o);} finally { l.unlock(); }
    }
    public final int hashCode() {
        final ReentrantReadWriteLock.ReadLock l =  rwl.readLock();
        l.lock(); try {return c.hashCode();} finally { l.unlock(); }
    }
    public final String toString() {
        final ReentrantReadWriteLock.ReadLock l =  rwl.readLock();
        l.lock(); try {return c.toString();} finally { l.unlock(); }
    }

    public final Iterator<E> iterator() {
        final ReentrantReadWriteLock.ReadLock l =  rwl.readLock();
        l.lock(); try {return c.iterator();} finally { l.unlock(); }
    }

    public final Object[] toArray() {
        final ReentrantReadWriteLock.ReadLock l =  rwl.readLock();
        l.lock(); try  {return c.toArray();} finally { l.unlock(); }
    }
    public final <T> T[] toArray(T[] a) {
        final ReentrantReadWriteLock.ReadLock l =  rwl.readLock();
        l.lock(); try  {return (T[])c.toArray(a);} finally { l.unlock(); }
    }

    public final boolean add(E e) {
        final ReentrantReadWriteLock.WriteLock l =  rwl.writeLock();
        l.lock(); try  {return c.add(e);} finally { l.unlock(); }
    }
    public final boolean remove(Object o) {
        final ReentrantReadWriteLock.WriteLock l =  rwl.writeLock();
        l.lock(); try  {return c.remove(o);} finally { l.unlock(); }
    }

    public final boolean containsAll(Collection<?> coll) {
        final ReentrantReadWriteLock.WriteLock l =  rwl.writeLock();
        l.lock(); try  {return c.containsAll(coll);} finally { l.unlock(); }
    }
    public final boolean addAll(Collection<? extends E> coll) {
        final ReentrantReadWriteLock.WriteLock l =  rwl.writeLock();
        l.lock(); try  {return c.addAll(coll);} finally { l.unlock(); }
    }
    public final boolean removeAll(Collection<?> coll) {
        final ReentrantReadWriteLock.WriteLock l =  rwl.writeLock();
        l.lock(); try  {return c.removeAll(coll);} finally { l.unlock(); }
    }
    public final boolean retainAll(Collection<?> coll) {
        final ReentrantReadWriteLock.WriteLock l =  rwl.writeLock();
        l.lock(); try  {return c.retainAll(coll);} finally { l.unlock(); }
    }
    public final void clear() {
        final ReentrantReadWriteLock.WriteLock l =  rwl.writeLock();
        l.lock(); try  {c.clear();} finally { l.unlock(); }
    }

}