/* * 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/publicdomain/zero/1.0/ */ 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 Maps. * Exists as a sample input for MapLoops test. */ public class RWMap implements Map { private final Map m; private final ReentrantReadWriteLock rwl = new ReentrantReadWriteLock(); public RWMap(Map m) { if (m == null) throw new NullPointerException(); this.m = m; } public RWMap() { this(new TreeMap()); // use TreeMap by default // this(new IdentityHashMap()); } public int size() { ReentrantReadWriteLock.ReadLock l = rwl.readLock(); l.lock(); try { return m.size(); } finally { l.unlock(); } } public boolean isEmpty() { ReentrantReadWriteLock.ReadLock l = rwl.readLock(); l.lock(); try { return m.isEmpty(); } finally { l.unlock(); } } public Object get(Object key) { ReentrantReadWriteLock.ReadLock l = rwl.readLock(); l.lock(); try { return m.get(key); } finally { l.unlock(); } } public boolean containsKey(Object key) { ReentrantReadWriteLock.ReadLock l = rwl.readLock(); l.lock(); try { return m.containsKey(key); } finally { l.unlock(); } } public boolean containsValue(Object value) { ReentrantReadWriteLock.ReadLock l = rwl.readLock(); l.lock(); try { return m.containsValue(value); } finally { l.unlock(); } } public Set keySet() { // Not implemented return m.keySet(); } public Set entrySet() { // Not implemented return m.entrySet(); } public Collection values() { // Not implemented return m.values(); } public boolean equals(Object o) { ReentrantReadWriteLock.ReadLock l = rwl.readLock(); l.lock(); try { return m.equals(o); } finally { l.unlock(); } } public int hashCode() { ReentrantReadWriteLock.ReadLock l = rwl.readLock(); l.lock(); try { return m.hashCode(); } finally { l.unlock(); } } public String toString() { ReentrantReadWriteLock.ReadLock l = rwl.readLock(); l.lock(); try { return m.toString(); } finally { l.unlock(); } } public Object put(Object key, Object value) { ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); l.lock(); try { return m.put(key, value); } finally { l.unlock(); } } public Object remove(Object key) { ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); l.lock(); try { return m.remove(key); } finally { l.unlock(); } } public void putAll(Map map) { ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); l.lock(); try { m.putAll(map); } finally { l.unlock(); } } public void clear() { ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); l.lock(); try { m.clear(); } finally { l.unlock(); } } }