Synchronized hashmap read-only access in Java

[spyrian]

In Java, there are 3 threads that want to access (read-only) an immutable hashmap to do something. Is \[code\]SynchronizedMap\[/code\] class below the fastest solution for that purpose? If not, then what would be faster to use?\[code\]import com.carrotsearch.hppc.IntObjectMap;import com.carrotsearch.hppc.IntObjectOpenHashMap;public class abc { public static void main(String[] args) { final IntObjectMap<int[]> map = new IntObjectOpenHashMap<int[]>(); for (int i = 0; i < 4; i++) { map.put(i, new int[] {1, 2, 3, 4, 5}); } Thread[] threads = new Thread[3]; class SynchronizedMap { private final Object syncObject = new Object(); public final int[] read(int i) { final int[] value; synchronized (syncObject) { // code that reads-only immutable map object value = http://stackoverflow.com/questions/15751224/map.get(i); } return value; } } final SynchronizedMap syncMap = new SynchronizedMap(); class AccessMap implements Runnable { private int id; AccessMap(int index) { id = index; } public void run() { // code that reads-only immutable map object like this: for (int i = 0; i < 4; i++) { final int[] array = syncMap.read(i); for (int j = 0; j < array.length; j++) System.out.println(id +": " + array[j] + " "); } } } for (int i = 0; i < threads.length; i++) { threads = new Thread(new AccessMap(i) {}); threads.start(); } for (int i = 0; i < threads.length; i++) { try { threads.join(); } catch (InterruptedException e) { e.printStackTrace(); } } }}\[/code\]