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root/jsr166/jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java

Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.30 by dl, Fri Nov 21 17:50:28 2003 UTC vs.
Revision 1.31 by dl, Fri Nov 28 12:37:00 2003 UTC

#	Line 289 | Line 289 | public class ConcurrentHashMap<K, V> ext
289		return false;
290		}
291
292	+	boolean replace(K key, int hash, V oldValue, V newValue) {
293	+	lock();
294	+	try {
295	+	int c = count;
296	+	HashEntry[] tab = table;
297	+	int index = hash & (tab.length - 1);
298	+	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
299	+	HashEntry<K,V> e = first;
300	+	for (;;) {
301	+	if (e == null)
302	+	return false;
303	+	if (e.hash == hash && key.equals(e.key))
304	+	break;
305	+	e = e.next;
306	+	}
307	+
308	+	V v = e.value;
309	+	if (v == null || !oldValue.equals(v))
310	+	return false;
311	+
312	+	e.value = newValue;
313	+	count = c; // write-volatile
314	+	return true;
315	+
316	+	} finally {
317	+	unlock();
318	+	}
319	+	}
320	+
321		V put(K key, int hash, V value, boolean onlyIfAbsent) {
322		lock();
323		try {
#	Line 796 | Line 825 | public class ConcurrentHashMap<K, V> ext
825		}
826
827		/**
828	+	* Replace entry for key only if currently mapped to given value.
829	+	* Acts as
830	+	* <pre>
831	+	*  if (map.get(key).equals(oldValue)) {
832	+	*     map.put(key, newValue);
833	+	*     return true;
834	+	* } else return false;
835	+	* </pre>
836	+	* except that the action is performed atomically.
837	+	* @param key key with which the specified value is associated.
838	+	* @param oldValue value expected to be associated with the specified key.
839	+	* @param newValue value to be associated with the specified key.
840	+	* @return true if the value was replaced
841	+	* @throws NullPointerException if the specified key or values are
842	+	* <tt>null</tt>.
843	+	*/
844	+	public boolean replace(K key, V oldValue, V newValue) {
845	+	if (oldValue == null || newValue == null)
846	+	throw new NullPointerException();
847	+	int hash = hash(key);
848	+	return segmentFor(hash).replace(key, hash, oldValue, newValue);
849	+	}
850	+
851	+
852	+	/**
853		* Removes all mappings from this map.
854		*/
855		public void clear() {

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