Author: julien_viet Date: 2011-06-09 17:24:49 -0400 (Thu, 09 Jun 2011) New Revision: 6621 Modified: components/common/trunk/common/src/main/java/org/gatein/common/concurrent/BoundedBuffer.java components/common/trunk/common/src/main/java/org/gatein/common/concurrent/ObjectRef.java Log: GTNCOMMON-16 : Decrease synchronization in BoundedBuffer Modified: components/common/trunk/common/src/main/java/org/gatein/common/concurrent/BoundedBuffer.java =================================================================== --- components/common/trunk/common/src/main/java/org/gatein/common/concurrent/BoundedBuffer.java 2011-06-09 11:35:59 UTC (rev 6620) +++ components/common/trunk/common/src/main/java/org/gatein/common/concurrent/BoundedBuffer.java 2011-06-09 21:24:49 UTC (rev 6621) @@ -60,7 +60,7 @@ private ObjectRef<T> first; /** The size, it is declared as volatile for the @link{getSize()} method. */ - private volatile int size; + private int size; public BoundedBuffer(int maxSize) { @@ -79,11 +79,6 @@ return maxSize; } - public int getSize() - { - return size; - } - /** * Add an element to the buffer. * @@ -91,26 +86,26 @@ */ public void add(T t) { + ObjectRef<T> added = new ObjectRef<T>(t); synchronized (this) { if (first == null) { - first = new ObjectRef<T>(t); - last = first; + last = first = added; size = 1; } else { ObjectRef<T> tmp = first; - first = new ObjectRef<T>(t); - tmp.next.set(first); + first = added; + tmp.next = first; if (size < maxSize) { size++; } else { - last = last.next.get(); + last = last.next; } } } @@ -124,22 +119,20 @@ */ public Iterator<T> iterator() { + ObjectRef<T> last; + int size; + synchronized (this) + { + last = this.last; + size = this.size; + } if (size == 0) { - List<T> empty = Collections.emptyList(); - return empty.iterator(); + return Collections.<T>emptyList().iterator(); } else { - // Get consistent state - final ObjectRef<T> lastSnapshot; - final int sizeSnapshot; - synchronized (this) - { - lastSnapshot = last; - sizeSnapshot = size; - } - return new BoundedIterator<T>(lastSnapshot, sizeSnapshot); + return new BoundedIterator<T>(last, size); } } @@ -171,7 +164,7 @@ throw new NoSuchElementException(); } T next = current.object; - current = current.next.get(); + current = current.next; count++; return next; } Modified: components/common/trunk/common/src/main/java/org/gatein/common/concurrent/ObjectRef.java =================================================================== --- components/common/trunk/common/src/main/java/org/gatein/common/concurrent/ObjectRef.java 2011-06-09 11:35:59 UTC (rev 6620) +++ components/common/trunk/common/src/main/java/org/gatein/common/concurrent/ObjectRef.java 2011-06-09 21:24:49 UTC (rev 6621) @@ -18,8 +18,6 @@ */ package org.gatein.common.concurrent; -import java.util.concurrent.atomic.AtomicReference; - /** * An internal class to keep a reference onto another object, it is used in the bounded buffer implementation. * @@ -33,11 +31,11 @@ final T object; /** . */ - final AtomicReference<ObjectRef<T>> next; + volatile ObjectRef<T> next; ObjectRef(T object) { this.object = object; - this.next = new AtomicReference<ObjectRef<T>>(); + this.next = null; } }