gistfile1.txt

package com.thenet.training.threads;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import com.thenet.training.ass6.Person;

public class MapCheck {

	public long getMax(List<MapThread> threads) {
		long max = 0;
		for (int i = 0; i < threads.size(); i++) {
			if (threads.get(i).time > max) {
				max = threads.get(i).time;
			}
		}
		
		return max;
	}

	public void runCWith3Threads() {
		System.out.println("WARM UP ....");
		for (int i = 0; i < 500; i++) {
			Map<Integer, Person> shm = Collections.synchronizedMap(new HashMap<Integer, Person>());
			Map<Integer, Person> chm = new ConcurrentHashMap<Integer, Person>(20000);

			test(shm, 2, 1000, "SynchronizedMap");
			test(chm, 2, 1000, "ConcurrentMap" );		
			
			if (i % 100 == 0) {
				System.out.println( (i / 100) + " warm up");
			}
		}
		
		System.out.println("TESTING ....");
		
		for (int i = 0; i < 5; i++) {
			Map<Integer, Person> shm = Collections.synchronizedMap(new HashMap<Integer, Person>());
			Map<Integer, Person> chm = new ConcurrentHashMap<Integer, Person>(100000);
			
			System.out.println(test(shm, 4, 10000 * (i + 1), "SynchronizedMap"));
			System.out.println(test(chm, 4, 10000 * (i + 1), "ConcurrentMap" ));		
			
			System.out.println();
		}
	}

	private String test(Map<Integer, Person> map, int threadNo, int objNum, String type) {
		List<MapThread> threads = new ArrayList<MapThread>();

		for (int t = 1; t <= threadNo ; t++) {
			threads.add(new MapThread(map, objNum * (t - 1), objNum * t));
		}

		for (int t = 0; t < threadNo; t++) {
			threads.get(t).start();
		}
		
		while (true) {
			try {
				for (int t = 0; t < threadNo; t++) {
					threads.get(t).join();
				}
				break;
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}

		return threadNo + " threads for " + objNum + " objects of  " + type + " cost: " + getMax(threads);
	}

	public class MapThread extends Thread {
		Map<Integer, Person> map;
		int from;
		int to;
		long time;
		

		public MapThread(Map<Integer, Person> map, int from, int to) {
			this.map = map;
			this.from = from;
			this.to = to;
		}

		public void run() {

			long start = System.nanoTime();
			for (int i = from; i < to; i++) {
				map.put(i, new Person());
			}
			long end = System.nanoTime();
			time = (end - start) / 1000000;
			return;
		}
	}

	public static void main(String[] args) {
		MapCheck check = new MapCheck();
		check.runCWith3Threads();
	}	
}