| /* |
| * Copyright 2009-2010 by The Regents of the University of California |
| * 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 from |
| * |
| * 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 edu.uci.ics.hyracks.control.common.work; |
| |
| public class FutureValue<T> implements IResultCallback<T> { |
| private boolean done; |
| |
| private T value; |
| |
| private Exception e; |
| |
| public FutureValue() { |
| done = false; |
| value = null; |
| e = null; |
| } |
| |
| @Override |
| public synchronized void setValue(T value) { |
| done = true; |
| this.value = value; |
| e = null; |
| notifyAll(); |
| } |
| |
| @Override |
| public synchronized void setException(Exception e) { |
| done = true; |
| this.e = e; |
| value = null; |
| notifyAll(); |
| } |
| |
| public synchronized void reset() { |
| done = false; |
| value = null; |
| e = null; |
| notifyAll(); |
| } |
| |
| public synchronized T get() throws Exception { |
| while (!done) { |
| wait(); |
| } |
| if (e != null) { |
| throw e; |
| } |
| return value; |
| } |
| } |