| 1 | package org.jtoolkit.essence.concurrency.impl; |
| 2 | |
| 3 | import org.jetbrains.annotations.NotNull; |
| 4 | import org.jtoolkit.essence.concurrency.CallbackEx; |
| 5 | import org.jtoolkit.essence.concurrency.Timeout; |
| 6 | import org.jtoolkit.essence.utils.Closeable; |
| 7 | |
| 8 | import java.util.ArrayList; |
| 9 | import java.util.List; |
| 10 | import java.util.concurrent.*; |
| 11 | |
| 12 | /* |
| 13 | Copyright 2006 Peter Lawrey |
| 14 | |
| 15 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 16 | you may not use this file except in compliance with the License. |
| 17 | You may obtain a copy of the License at |
| 18 | |
| 19 | http://www.apache.org/licenses/LICENSE-2.0 |
| 20 | |
| 21 | Unless required by applicable law or agreed to in writing, software |
| 22 | distributed under the License is distributed on an "AS IS" BASIS, |
| 23 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 24 | See the License for the specific language governing permissions and |
| 25 | limitations under the License. |
| 26 | */ |
| 27 | |
| 28 | /** |
| 29 | * @author Peter Lawrey |
| 30 | */ |
| 31 | public class CallbackQueue<E> implements CallbackEx<E>, Closeable { |
| 32 | private final BlockingQueue<Object> queue = new LinkedBlockingQueue<Object>(); |
| 33 | private boolean closed = false; |
| 34 | |
| 35 | public void onCallback(@NotNull E element) throws IllegalStateException { |
| 36 | checkClosed(); |
| 37 | queue.add(element); |
| 38 | } |
| 39 | |
| 40 | public void onException(@NotNull Throwable t) throws IllegalStateException { |
| 41 | checkClosed(); |
| 42 | queue.add(t); |
| 43 | } |
| 44 | |
| 45 | public E take(Timeout timeout) throws InterruptedException, TimeoutException, ExecutionException { |
| 46 | checkClosed(); |
| 47 | Object element; |
| 48 | if (timeout.isNever()) |
| 49 | element = queue.take(); |
| 50 | else { |
| 51 | long timeout2 = timeout.getMillisLeft(); |
| 52 | if (timeout2 <= 0) |
| 53 | element = queue.poll(); |
| 54 | else |
| 55 | element = queue.poll(timeout2, TimeUnit.MILLISECONDS); |
| 56 | } |
| 57 | if (element == null) |
| 58 | throw new TimeoutException("After " + timeout); |
| 59 | |
| 60 | if (element instanceof Throwable) |
| 61 | throw new ExecutionException((Throwable) element); |
| 62 | return (E) element; |
| 63 | } |
| 64 | |
| 65 | private void checkClosed() { |
| 66 | if (closed) throw new IllegalStateException(CLOSED); |
| 67 | } |
| 68 | |
| 69 | public List drain(int maxCount, Timeout timeout) throws InterruptedException { |
| 70 | // long start = System.nanoTime(); |
| 71 | List ret = new ArrayList(); |
| 72 | queue.drainTo(ret, maxCount); |
| 73 | while (!closed && ret.size() < maxCount) { |
| 74 | long millisLeft = timeout.getMillisLeft(); |
| 75 | if (millisLeft < 0) break; |
| 76 | Object element2; |
| 77 | if (millisLeft == 0) { |
| 78 | element2 = queue.poll(); |
| 79 | if (element2 == null) { |
| 80 | // noinspection CallToThreadYield |
| 81 | Thread.yield(); |
| 82 | element2 = queue.poll(); |
| 83 | } |
| 84 | if (element2 == null) break; |
| 85 | } else { |
| 86 | element2 = queue.poll(millisLeft, TimeUnit.MILLISECONDS); |
| 87 | } |
| 88 | if (element2 != null) |
| 89 | ret.add(element2); |
| 90 | } |
| 91 | return ret; |
| 92 | } |
| 93 | |
| 94 | public String toString() { |
| 95 | return "CallbackQueue " + queue; |
| 96 | } |
| 97 | |
| 98 | public void close() { |
| 99 | closed = true; |
| 100 | queue.add(null); |
| 101 | } |
| 102 | |
| 103 | public boolean isClosed() { |
| 104 | return closed; |
| 105 | } |
| 106 | } |