1/*
2 * Copyright (C) 2016 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
17package libcore.java.nio.channels;
18
19import java.nio.channels.CompletionHandler;
20
21/** A CompletionHandler that behaves like a Future and enables compact, single-threaded tests. */
22public class FutureLikeCompletionHandler<V> implements CompletionHandler<V, Object> {
23    Throwable e;
24    boolean done;
25    V result;
26    Object attachment;
27
28    public void completed(V result, Object attachment) {
29        synchronized (this) {
30            if (done) {
31                e = new IllegalStateException("CompletionHandler used twice");
32            }
33            this.result = result;
34            this.done = true;
35            this.attachment = attachment;
36            this.notifyAll();
37        }
38    }
39
40    public void failed(Throwable exc, Object attachment) {
41        synchronized (this) {
42            if (done) {
43                e = new IllegalStateException("CompletionHandler used twice");
44            }
45            this.e = exc;
46            this.done = true;
47            this.attachment = attachment;
48            this.notifyAll();
49        }
50    }
51
52    V get(long timeoutMiliseconds) throws Throwable {
53        synchronized (this) {
54            while (!done) {
55                wait(timeoutMiliseconds);
56            }
57            if (e != null) {
58                throw e;
59            }
60            return result;
61        }
62    }
63
64    public Object getAttachment() {
65        synchronized (this) {
66            return attachment;
67        }
68    }
69}
70