| 1 | /* |
| 2 | * Copyright 2002-2007 the original author or authors. |
| 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 org.springframework.batch.repeat.support; |
| 18 | |
| 19 | import edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue; |
| 20 | import edu.emory.mathcs.backport.java.util.concurrent.LinkedBlockingQueue; |
| 21 | import edu.emory.mathcs.backport.java.util.concurrent.Semaphore; |
| 22 | |
| 23 | /** |
| 24 | * An implementation of the {@link ResultQueue} that uses Backport Concurrent Utilities. |
| 25 | * |
| 26 | * @author Ben Hale |
| 27 | */ |
| 28 | class BackportConcurrentResultQueue extends AbstractResultQueue implements RepeatInternalState { |
| 29 | |
| 30 | // Accumulation of result objects as they finish. |
| 31 | private final BlockingQueue results; |
| 32 | |
| 33 | // Accumulation of dummy objects flagging expected results in the future. |
| 34 | private final Semaphore waits; |
| 35 | |
| 36 | BackportConcurrentResultQueue(int throttleLimit) { |
| 37 | results = new LinkedBlockingQueue(); |
| 38 | waits = new Semaphore(throttleLimit); |
| 39 | } |
| 40 | |
| 41 | protected void addResult(ResultHolder resultHolder) { |
| 42 | results.add(resultHolder); |
| 43 | } |
| 44 | |
| 45 | protected void aquireWait() throws InterruptedException { |
| 46 | waits.acquire(); |
| 47 | } |
| 48 | |
| 49 | protected void releaseWait() { |
| 50 | waits.release(); |
| 51 | } |
| 52 | |
| 53 | protected ResultHolder takeResult() throws InterruptedException { |
| 54 | return (ResultHolder) results.take(); |
| 55 | } |
| 56 | |
| 57 | public boolean isEmpty() { |
| 58 | return results.isEmpty(); |
| 59 | } |
| 60 | |
| 61 | } |