Source Code : Coarse-grained hash set.

Java Is Open Source Programming Language You Can Download From Java and Java Libraries From http://www.oracle.com. Click Here to download
We provide this code related to title for you to solve your developing problem easily. Libraries which is import in this program you can download from http://www.oracle.com. Click Here or search from google with Libraries Name you get jar file related it

Coarse-grained hash set.

     
/*
 * CoarseHashSet.java
 *
 * Created on December 29, 2005, 11:50 PM
 *
 * From "The Art of Multiprocessor Programming",
 * by Maurice Herlihy and Nir Shavit.
 *
 * This work is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.
 * http://i.creativecommons.org/l/by-sa/3.0/us/88x31.png
 */
//package xbird.util.concurrent.set;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * Coarse-grained hash set.
 * @param <T> type
 * @author Maurice Herlihy
 */
public class CoarseHashSet<T> extends BaseHashSet<T> {
    final Lock lock;

    CoarseHashSet(int capacity) {
        super(capacity);
        lock = new ReentrantLock();
    }

    /**
     * double the set size
     */
    @Override
    public void resize() {
        int oldCapacity = table.length;
        lock.lock();
        try {
            if(oldCapacity != table.length) {
                return; // someone beat us to it
            }
            int newCapacity = 2 * oldCapacity;
            List<T>[] oldTable = table;
            table = (List<T>[]) new List[newCapacity];
            for(int i = 0; i < newCapacity; i++)
                table[i] = new ArrayList<T>();
            for(List<T> bucket : oldTable) {
                for(T x : bucket) {
                    int myBucket = Math.abs(x.hashCode() % table.length);
                    table[myBucket].add(x);
                }
            }
        } finally {
            lock.unlock();
        }
    }

    /**
     * Synchronize before adding, removing, or testing for item
     * @param x item involved
     */
    @Override
    public final void acquire(T x) {
        lock.lock();
    }

    /**
     * synchronize after adding, removing, or testing for item
     * @param x item involved
     */
    @Override
    public void release(T x) {
        lock.unlock();
    }

    @Override
    public boolean policy() {
        return size / table.length > 4;
    }
}



/**
 * Simple fine-grained hash map.
 * @param <T> type
 * @author Maurice Herlihy
 */
 abstract class BaseHashSet<T> {
    protected List<T>[] table;
    protected int size;

    public BaseHashSet(int capacity) {
        size = 0;
        table = (List<T>[]) new List[capacity];
        for(int i = 0; i < capacity; i++) {
            table[i] = new ArrayList<T>();
        }
    }

    /**
     * Is item in set?
     * @param x item to test
     * @return <code>true</code> iff item present
     */
    public boolean contains(T x) {
        acquire(x);
        try {
            int myBucket = Math.abs(x.hashCode() % table.length);
            return table[myBucket].contains(x);
        } finally {
            release(x);
        }
    }

    /**
     * Add item to set
     * @param x item to add
     * @return <code>true</code> iff set changed
     */
    public boolean add(T x) {
        boolean result = false;
        acquire(x);
        try {
            int myBucket = Math.abs(x.hashCode() % table.length);
            result = table[myBucket].add(x);
            size = result ? size + 1 : size;
        } finally {
            release(x); // always unlock
        }
        if(policy())
            resize();
        return result;
    }

    /**
     * Remove item from set
     * @param x item to remove
     * @return <code>true</code> iff set changed
     */
    public boolean remove(T x) {
        acquire(x);
        try {
            int myBucket = Math.abs(x.hashCode() % table.length);
            boolean result = table[myBucket].remove(x);
            size = result ? size - 1 : size;
            return result;
        } finally {
            release(x); // always unlock
        }
    }

    /**
     * Synchronize before adding, removing, or testing for item
     * @param x item involved
     */
    public abstract void acquire(T x);

    /**
     * synchronize after adding, removing, or testing for item
     * @param x item involved
     */
    public abstract void release(T x);

    /**
     * double the set size
     */
    public abstract void resize();

    /**
     * decide whether to resize
     * @return whether to resize
     */
    public abstract boolean policy();

}

   
    
    
    
    
  

Thank with us