1 /*
2 * Copyright 2013 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://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, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty5.util.concurrent;
17
18 /**
19 * Special {@link Future} which is writable.
20 */
21 public interface Promise<V> extends AsynchronousResult<V> {
22 /**
23 * Marks this promise as a success and notifies all listeners attached to the {@linkplain #asFuture() future}.
24 * <p>
25 * If it is success or failed already it will throw an {@link IllegalStateException}.
26 */
27 Promise<V> setSuccess(V result);
28
29 /**
30 * Marks this future as a success and notifies all listeners.
31 *
32 * @return {@code true} if and only if successfully marked this promise as a success.
33 * Otherwise {@code false} because this promise is already marked as either a success or a failure.
34 */
35 boolean trySuccess(V result);
36
37 /**
38 * Marks this promise as a failure and notifies all listeners attached to the {@linkplain #asFuture() future}.
39 * <p>
40 * If it is success or failed already it will throw an {@link IllegalStateException}.
41 */
42 Promise<V> setFailure(Throwable cause);
43
44 /**
45 * Marks this promise as a failure and notifies all listeners.
46 *
47 * @return {@code true} if and only if successfully marked this promise as a failure.
48 * Otherwise {@code false} because this promise is already marked as either a success or a failure.
49 */
50 boolean tryFailure(Throwable cause);
51
52 /**
53 * Make this promise impossible to cancel.
54 *
55 * @return {@code true} if and only if successfully marked this promise as uncancellable.
56 * Otherwise {@code false} if this promise has been cancelled already, or has completed.
57 */
58 boolean setUncancellable();
59
60 /**
61 * Return the {@link Future} instance is associated with this promise.
62 * This future will be completed upon completion of this promise.
63 *
64 * @return A future instance associated with this promise.
65 */
66 Future<V> asFuture();
67 }