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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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import java.util.*; |
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import java.util.concurrent.*; |
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import java.util.concurrent.locks.*; |
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|
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/** |
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* This is an incomplete implementation of a wrapper class |
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* that places read-write locks around unsynchronized Maps. |
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* Exists as a sample input for MapLoops test. |
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*/ |
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public class RWMap implements ConcurrentMap { |
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private final Map m; |
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private final ReentrantReadWriteLock rwl = new ReentrantReadWriteLock(); |
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|
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public RWMap(Map m) { |
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if (m == null) |
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throw new NullPointerException(); |
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this.m = m; |
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} |
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|
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public RWMap() { |
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this(new TreeMap()); // use TreeMap by default |
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// this(new IdentityHashMap()); |
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} |
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|
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public int size() { |
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ReentrantReadWriteLock.ReadLock l = rwl.readLock(); |
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l.lock(); |
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try { return m.size(); } |
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finally { l.unlock(); } |
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} |
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|
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public boolean isEmpty() { |
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ReentrantReadWriteLock.ReadLock l = rwl.readLock(); |
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l.lock(); |
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try { return m.isEmpty(); } |
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finally { l.unlock(); } |
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} |
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|
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public Object get(Object key) { |
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ReentrantReadWriteLock.ReadLock l = rwl.readLock(); |
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l.lock(); |
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try { return m.get(key); } |
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finally { l.unlock(); } |
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} |
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|
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public boolean containsKey(Object key) { |
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ReentrantReadWriteLock.ReadLock l = rwl.readLock(); |
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l.lock(); |
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try { return m.containsKey(key); } |
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finally { l.unlock(); } |
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} |
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|
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public boolean containsValue(Object value) { |
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ReentrantReadWriteLock.ReadLock l = rwl.readLock(); |
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l.lock(); |
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try { return m.containsValue(value); } |
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finally { l.unlock(); } |
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} |
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|
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public Set keySet() { // Not implemented |
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return m.keySet(); |
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} |
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|
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public Set entrySet() { // Not implemented |
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return m.entrySet(); |
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} |
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|
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public Collection values() { // Not implemented |
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return m.values(); |
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} |
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|
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public boolean equals(Object o) { |
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ReentrantReadWriteLock.ReadLock l = rwl.readLock(); |
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l.lock(); |
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try { return m.equals(o); } |
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finally { l.unlock(); } |
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} |
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|
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public int hashCode() { |
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ReentrantReadWriteLock.ReadLock l = rwl.readLock(); |
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l.lock(); |
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try { return m.hashCode(); } |
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finally { l.unlock(); } |
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} |
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|
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public String toString() { |
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ReentrantReadWriteLock.ReadLock l = rwl.readLock(); |
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l.lock(); |
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try { return m.toString(); } |
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finally { l.unlock(); } |
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} |
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|
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public Object put(Object key, Object value) { |
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ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); |
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l.lock(); |
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try { return m.put(key, value); } |
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finally { l.unlock(); } |
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} |
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|
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public Object putIfAbsent(Object key, Object value) { |
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ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); |
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l.lock(); |
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try { |
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Object v = m.get(key); |
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return (v == null) ? m.put(key, value) : v; |
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} |
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finally { l.unlock(); } |
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} |
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|
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public boolean replace(Object key, Object oldValue, Object newValue) { |
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ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); |
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l.lock(); |
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try { |
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if (m.get(key).equals(oldValue)) { |
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m.put(key, newValue); |
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return true; |
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} |
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return false; |
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} |
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finally { l.unlock(); } |
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} |
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|
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public Object replace(Object key, Object newValue) { |
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ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); |
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l.lock(); |
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try { |
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if (m.containsKey(key)) |
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return m.put(key, newValue); |
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return null; |
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} |
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finally { l.unlock(); } |
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} |
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|
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public Object remove(Object key) { |
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ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); |
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l.lock(); |
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try { return m.remove(key); } |
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finally { l.unlock(); } |
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} |
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|
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public boolean remove(Object key, Object value) { |
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ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); |
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l.lock(); |
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try { |
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if (m.get(key).equals(value)) { |
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m.remove(key); |
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return true; |
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} |
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return false; |
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} |
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finally { l.unlock(); } |
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} |
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|
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public void putAll(Map map) { |
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ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); |
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l.lock(); |
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try { m.putAll(map); } |
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finally { l.unlock(); } |
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} |
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|
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public void clear() { |
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ReentrantReadWriteLock.WriteLock l = rwl.writeLock(); |
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l.lock(); |
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try { m.clear(); } |
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finally { l.unlock(); } |
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} |
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|
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} |
