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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.googlecode.android_scripting.future;
     18 
     19 import java.util.concurrent.CountDownLatch;
     20 import java.util.concurrent.Future;
     21 import java.util.concurrent.TimeUnit;
     22 
     23 /**
     24  * FutureResult represents an eventual execution result for asynchronous operations.
     25  *
     26  */
     27 public class FutureResult<T> implements Future<T> {
     28 
     29     private final CountDownLatch mLatch = new CountDownLatch(1);
     30     private volatile T mResult = null;
     31 
     32     public void set(T result) {
     33         mResult = result;
     34         mLatch.countDown();
     35     }
     36 
     37     @Override
     38     public boolean cancel(boolean mayInterruptIfRunning) {
     39         return false;
     40     }
     41 
     42     @Override
     43     public T get() throws InterruptedException {
     44         mLatch.await();
     45         return mResult;
     46     }
     47 
     48     @Override
     49     public T get(long timeout, TimeUnit unit) throws InterruptedException {
     50         mLatch.await(timeout, unit);
     51         return mResult;
     52     }
     53 
     54     @Override
     55     public boolean isCancelled() {
     56         return false;
     57     }
     58 
     59     @Override
     60     public boolean isDone() {
     61         return mResult != null;
     62     }
     63 
     64 }
     65