From 97b8365cafc3a344a22d3980b8ed885f5c6d8357 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Tue, 9 Jan 2007 19:58:05 +0000 Subject: Merged gcj-eclipse branch to trunk. From-SVN: r120621 --- .../jsr166/java/util/concurrent/ConcurrentMap.java | 134 +++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 libjava/classpath/external/jsr166/java/util/concurrent/ConcurrentMap.java (limited to 'libjava/classpath/external/jsr166/java/util/concurrent/ConcurrentMap.java') diff --git a/libjava/classpath/external/jsr166/java/util/concurrent/ConcurrentMap.java b/libjava/classpath/external/jsr166/java/util/concurrent/ConcurrentMap.java new file mode 100644 index 00000000000..6e5bd073880 --- /dev/null +++ b/libjava/classpath/external/jsr166/java/util/concurrent/ConcurrentMap.java @@ -0,0 +1,134 @@ +/* + * 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/licenses/publicdomain + */ + +package java.util.concurrent; +import java.util.Map; + +/** + * A {@link java.util.Map} providing additional atomic + * putIfAbsent, remove, and replace methods. + * + *

Memory consistency effects: As with other concurrent + * collections, actions in a thread prior to placing an object into a + * {@code ConcurrentMap} as a key or value + * happen-before + * actions subsequent to the access or removal of that object from + * the {@code ConcurrentMap} in another thread. + * + *

This interface is a member of the + * + * Java Collections Framework. + * + * @since 1.5 + * @author Doug Lea + * @param the type of keys maintained by this map + * @param the type of mapped values + */ +public interface ConcurrentMap extends Map { + /** + * If the specified key is not already associated + * with a value, associate it with the given value. + * This is equivalent to + * 

+     *   if (!map.containsKey(key))
+     *       return map.put(key, value);
+     *   else
+     *       return map.get(key);
+ * except that the action is performed atomically. + * + * @param key key with which the specified value is to be associated + * @param value value to be associated with the specified key + * @return the previous value associated with the specified key, or + * null if there was no mapping for the key. + * (A null return can also indicate that the map + * previously associated null with the key, + * if the implementation supports null values.) + * @throws UnsupportedOperationException if the put operation + * is not supported by this map + * @throws ClassCastException if the class of the specified key or value + * prevents it from being stored in this map + * @throws NullPointerException if the specified key or value is null, + * and this map does not permit null keys or values + * @throws IllegalArgumentException if some property of the specified key + * or value prevents it from being stored in this map + * + */ + V putIfAbsent(K key, V value); + + /** + * Removes the entry for a key only if currently mapped to a given value. + * This is equivalent to + * 
+     *   if (map.containsKey(key) && map.get(key).equals(value)) {
+     *       map.remove(key);
+     *       return true;
+     *   } else return false;
+ * except that the action is performed atomically. + * + * @param key key with which the specified value is associated + * @param value value expected to be associated with the specified key + * @return true if the value was removed + * @throws UnsupportedOperationException if the remove operation + * is not supported by this map + * @throws ClassCastException if the key or value is of an inappropriate + * type for this map (optional) + * @throws NullPointerException if the specified key or value is null, + * and this map does not permit null keys or values (optional) + */ + boolean remove(Object key, Object value); + + /** + * Replaces the entry for a key only if currently mapped to a given value. + * This is equivalent to + * 
+     *   if (map.containsKey(key) && map.get(key).equals(oldValue)) {
+     *       map.put(key, newValue);
+     *       return true;
+     *   } else return false;
+ * except that the action is performed atomically. + * + * @param key key with which the specified value is associated + * @param oldValue value expected to be associated with the specified key + * @param newValue value to be associated with the specified key + * @return true if the value was replaced + * @throws UnsupportedOperationException if the put operation + * is not supported by this map + * @throws ClassCastException if the class of a specified key or value + * prevents it from being stored in this map + * @throws NullPointerException if a specified key or value is null, + * and this map does not permit null keys or values + * @throws IllegalArgumentException if some property of a specified key + * or value prevents it from being stored in this map + */ + boolean replace(K key, V oldValue, V newValue); + + /** + * Replaces the entry for a key only if currently mapped to some value. + * This is equivalent to + * 
+     *   if (map.containsKey(key)) {
+     *       return map.put(key, value);
+     *   } else return null;
+ * except that the action is performed atomically. + * + * @param key key with which the specified value is associated + * @param value value to be associated with the specified key + * @return the previous value associated with the specified key, or + * null if there was no mapping for the key. + * (A null return can also indicate that the map + * previously associated null with the key, + * if the implementation supports null values.) + * @throws UnsupportedOperationException if the put operation + * is not supported by this map + * @throws ClassCastException if the class of the specified key or value + * prevents it from being stored in this map + * @throws NullPointerException if the specified key or value is null, + * and this map does not permit null keys or values + * @throws IllegalArgumentException if some property of the specified key + * or value prevents it from being stored in this map + */ + V replace(K key, V value); +} -- cgit v1.2.3