co.paralleluniverse.concurrent.util.EnhancedAtomicLong Maven / Gradle / Ivy
/*
* Quasar: lightweight threads and actors for the JVM.
* Copyright (c) 2013-2015, Parallel Universe Software Co. All rights reserved.
*
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation
*
* or (per the licensee's choosing)
*
* under the terms of the GNU Lesser General Public License version 3.0
* as published by the Free Software Foundation.
*/
package co.paralleluniverse.concurrent.util;
import com.google.common.base.Function;
import com.google.common.base.Predicate;
import java.util.concurrent.atomic.AtomicLong;
/**
* Extension of {@link AtomicLong} with useful methods based on CAS.
*
* @author circlespainter
*/
public class EnhancedAtomicLong extends AtomicLong {
public static final Function DEC =
new Function() {
@Override
public Long apply(final Long l) {
return l - 1;
}
};
public static Predicate gt(final long n) {
return new Predicate() {
public boolean apply(final Long l) {
return l > n;
}
};
}
public boolean evalAndUpdate(final Predicate predicate, final Function update) {
long val;
boolean satisfied;
do {
val = get();
satisfied = predicate.apply(val);
} while (satisfied && !compareAndSet(val, update.apply(val)));
return satisfied;
}
}