org.testifyproject.guava.common.cache.LongAddables Maven / Gradle / Ivy
/*
* 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 org.testifyproject.guava.common.cache;
import org.testifyproject.guava.common.annotations.GwtCompatible;
import org.testifyproject.guava.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
*/
@GwtCompatible(emulated = true)
final class LongAddables {
private static final Supplier SUPPLIER;
static {
Supplier supplier;
try {
new LongAdder(); // trigger static initialization of the LongAdder class, which may fail
supplier =
new Supplier() {
@Override
public LongAddable get() {
return new LongAdder();
}
};
} catch (Throwable t) { // we really want to catch *everything*
supplier =
new Supplier() {
@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();
}
}
}