org.apache.hadoop.util.concurrent.AsyncGetFuture Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.hadoop.util.concurrent;
import org.apache.hadoop.thirdparty.com.google.common.util.concurrent.AbstractFuture;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
/** A {@link Future} implemented using an {@link AsyncGet} object. */
public class AsyncGetFuture extends AbstractFuture {
public static final Logger LOG =
LoggerFactory.getLogger(AsyncGetFuture.class);
private final AtomicBoolean called = new AtomicBoolean(false);
private final AsyncGet asyncGet;
public AsyncGetFuture(AsyncGet asyncGet) {
this.asyncGet = asyncGet;
}
private void callAsyncGet(long timeout, TimeUnit unit) {
if (!isCancelled() && called.compareAndSet(false, true)) {
try {
set(asyncGet.get(timeout, unit));
} catch (TimeoutException te) {
LOG.trace("TRACE", te);
called.compareAndSet(true, false);
} catch (Throwable e) {
LOG.trace("TRACE", e);
setException(e);
}
}
}
@Override
public T get() throws InterruptedException, ExecutionException {
callAsyncGet(-1, TimeUnit.MILLISECONDS);
return super.get();
}
@Override
public T get(long timeout, TimeUnit unit)
throws InterruptedException, TimeoutException, ExecutionException {
callAsyncGet(timeout, unit);
return super.get(0, TimeUnit.MILLISECONDS);
}
@Override
public boolean isDone() {
callAsyncGet(0, TimeUnit.MILLISECONDS);
return super.isDone();
}
}