util/concurrent/AtomicLinkedNode.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain. Use, modify, and
 * redistribute this code in any way without acknowledgement.
 */

package java.util.concurrent;
import java.util.concurrent.atomic.*;

/**
 * A linked list node supporting atomic operations on both item and
 * next fields, Used by non-blocking linked-list based classes.
 * @since 1.5
 * @author Doug Lea
 */

final class AtomicLinkedNode {
    private volatile Object item;
    private volatile AtomicLinkedNode next;

    private static final AtomicReferenceFieldUpdater<AtomicLinkedNode, AtomicLinkedNode> nextUpdater =
    new AtomicReferenceFieldUpdater<AtomicLinkedNode, AtomicLinkedNode>(new AtomicLinkedNode[0], new AtomicLinkedNode[0], "next");
    private static final AtomicReferenceFieldUpdater<AtomicLinkedNode, Object> itemUpdater
     = new AtomicReferenceFieldUpdater<AtomicLinkedNode, Object>(new AtomicLinkedNode[0], new Object[0], "item");

    AtomicLinkedNode(Object x) { item = x; }

    AtomicLinkedNode(Object x, AtomicLinkedNode n) { item = x; next = n; }

    Object getItem() {
        return item;
    }

    boolean casItem(Object cmp, Object val) {
        return itemUpdater.compareAndSet(this, cmp, val);
    }

    void setItem(Object val) {
        itemUpdater.set(this, val);
    }

    AtomicLinkedNode getNext() {
        return next;
    }

    boolean casNext(AtomicLinkedNode cmp, AtomicLinkedNode val) {
        return nextUpdater.compareAndSet(this, cmp, val);
    }

    void setNext(AtomicLinkedNode val) {
        nextUpdater.set(this, val);
    }

}
Revision:	1.2
Committed:	Tue Jun 24 14:34:47 2003 UTC (20 years, 11 months ago) by dl
Branch:	MAIN
CVS Tags:	JSR166_PRELIMINARY_TEST_RELEASE_2
Changes since 1.1:	+4 -2 lines
Log Message:	Added missing javadoc tags; minor reformatting
#	User	Rev	Content
1	dl	1.1	/*
2			* Written by Doug Lea with assistance from members of JCP JSR-166
3			* Expert Group and released to the public domain. Use, modify, and
4			* redistribute this code in any way without acknowledgement.
5			*/
6
7			package java.util.concurrent;
8			import java.util.concurrent.atomic.*;
9
10			/**
11			* A linked list node supporting atomic operations on both item and
12			* next fields, Used by non-blocking linked-list based classes.
13	dl	1.2	* @since 1.5
14			* @author Doug Lea
15	dl	1.1	*/
16
17			final class AtomicLinkedNode {
18			private volatile Object item;
19			private volatile AtomicLinkedNode next;
20
21	dl	1.2	private static final AtomicReferenceFieldUpdater<AtomicLinkedNode, AtomicLinkedNode> nextUpdater =
22	dl	1.1	new AtomicReferenceFieldUpdater<AtomicLinkedNode, AtomicLinkedNode>(new AtomicLinkedNode[0], new AtomicLinkedNode[0], "next");
23	dl	1.2	private static final AtomicReferenceFieldUpdater<AtomicLinkedNode, Object> itemUpdater
24	dl	1.1	= new AtomicReferenceFieldUpdater<AtomicLinkedNode, Object>(new AtomicLinkedNode[0], new Object[0], "item");
25
26			AtomicLinkedNode(Object x) { item = x; }
27
28			AtomicLinkedNode(Object x, AtomicLinkedNode n) { item = x; next = n; }
29
30			Object getItem() {
31			return item;
32			}
33
34			boolean casItem(Object cmp, Object val) {
35			return itemUpdater.compareAndSet(this, cmp, val);
36			}
37
38			void setItem(Object val) {
39			itemUpdater.set(this, val);
40			}
41
42			AtomicLinkedNode getNext() {
43			return next;
44			}
45
46			boolean casNext(AtomicLinkedNode cmp, AtomicLinkedNode val) {
47			return nextUpdater.compareAndSet(this, cmp, val);
48			}
49
50			void setNext(AtomicLinkedNode val) {
51			nextUpdater.set(this, val);
52			}
53
54			}