/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * This file is available under and governed by the GNU General Public * License version 2 only, as published by the Free Software Foundation. * However, the following notice accompanied the original version of this * file: * * 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/publicdomain/zero/1.0/ */ package java.util.concurrent.atomic; import java.util.function.LongUnaryOperator; import java.util.function.LongBinaryOperator; /** * A {@code long} value that may be updated atomically. See the * {@link java.util.concurrent.atomic} package specification for * description of the properties of atomic variables. An * {@code AtomicLong} is used in applications such as atomically * incremented sequence numbers, and cannot be used as a replacement * for a {@link java.lang.Long}. However, this class does extend * {@code Number} to allow uniform access by tools and utilities that * deal with numerically-based classes. * * @since 1.5 * @author Doug Lea */ // For desugar: Copy of j.u.c.a.AtomicLong with methods added with 1.8 public class DesugarAtomicLong { private DesugarAtomicLong() {} // for desugar: no instantiation, static members only /** * Atomically updates the current value with the results of * applying the given function, returning the previous value. The * function should be side-effect-free, since it may be re-applied * when attempted updates fail due to contention among threads. * * @param updateFunction a side-effect-free function * @return the previous value * @since 1.8 */ // For desugar: made static so it can exist outside original class public static long getAndUpdate(AtomicLong atomic, LongUnaryOperator updateFunction) { long prev, next; do { prev = atomic.get(); next = updateFunction.applyAsLong(prev); } while (!atomic.compareAndSet(prev, next)); return prev; } /** * Atomically updates the current value with the results of * applying the given function, returning the updated value. The * function should be side-effect-free, since it may be re-applied * when attempted updates fail due to contention among threads. * * @param updateFunction a side-effect-free function * @return the updated value * @since 1.8 */ // For desugar: made static so it can exist outside original class public static long updateAndGet(AtomicLong atomic, LongUnaryOperator updateFunction) { long prev, next; do { prev = atomic.get(); next = updateFunction.applyAsLong(prev); } while (!atomic.compareAndSet(prev, next)); return next; } /** * Atomically updates the current value with the results of * applying the given function to the current and given values, * returning the previous value. The function should be * side-effect-free, since it may be re-applied when attempted * updates fail due to contention among threads. The function * is applied with the current value as its first argument, * and the given update as the second argument. * * @param x the update value * @param accumulatorFunction a side-effect-free function of two arguments * @return the previous value * @since 1.8 */ // For desugar: made static so it can exist outside original class public static long getAndAccumulate(AtomicLong atomic, long x, LongBinaryOperator accumulatorFunction) { long prev, next; do { prev = atomic.get(); next = accumulatorFunction.applyAsLong(prev, x); } while (!atomic.compareAndSet(prev, next)); return prev; } /** * Atomically updates the current value with the results of * applying the given function to the current and given values, * returning the updated value. The function should be * side-effect-free, since it may be re-applied when attempted * updates fail due to contention among threads. The function * is applied with the current value as its first argument, * and the given update as the second argument. * * @param x the update value * @param accumulatorFunction a side-effect-free function of two arguments * @return the updated value * @since 1.8 */ // For desugar: made static so it can exist outside original class public static long accumulateAndGet(AtomicLong atomic, long x, LongBinaryOperator accumulatorFunction) { long prev, next; do { prev = atomic.get(); next = accumulatorFunction.applyAsLong(prev, x); } while (!atomic.compareAndSet(prev, next)); return next; } }