| /* |
| * Copyright (C) 2012 The Guava Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except |
| * in compliance with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software distributed under the License |
| * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express |
| * or implied. See the License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| |
| package com.google.common.hash; |
| |
| import com.google.common.base.Supplier; |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| /** |
| * Source of {@link LongAddable} objects that deals with GWT, Unsafe, and all that. |
| * |
| * @author Louis Wasserman |
| */ |
| final class LongAddables { |
| private static final Supplier<LongAddable> SUPPLIER; |
| |
| static { |
| Supplier<LongAddable> supplier; |
| try { |
| new LongAdder(); // trigger static initialization of the LongAdder class, which may fail |
| supplier = |
| new Supplier<LongAddable>() { |
| @Override |
| public LongAddable get() { |
| return new LongAdder(); |
| } |
| }; |
| } catch (Throwable t) { // we really want to catch *everything* |
| supplier = |
| new Supplier<LongAddable>() { |
| @Override |
| public LongAddable get() { |
| return new PureJavaLongAddable(); |
| } |
| }; |
| } |
| SUPPLIER = supplier; |
| } |
| |
| public static LongAddable create() { |
| return SUPPLIER.get(); |
| } |
| |
| private static final class PureJavaLongAddable extends AtomicLong implements LongAddable { |
| @Override |
| public void increment() { |
| getAndIncrement(); |
| } |
| |
| @Override |
| public void add(long x) { |
| getAndAdd(x); |
| } |
| |
| @Override |
| public long sum() { |
| return get(); |
| } |
| } |
| } |