1 /*
2 * Copyright 2015 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 * 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, 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.netty.channel.pool;
17
18 import io.netty.channel.Channel;
19 import io.netty.util.concurrent.Future;
20 import io.netty.util.concurrent.Promise;
21
22 import java.io.Closeable;
23 import java.io.IOException;
24
25 /**
26 * Allows to acquire and release {@link Channel} and so act as a pool of these.
27 */
28 public interface ChannelPool extends Closeable {
29
30 /**
31 * Acquire a {@link Channel} from this {@link ChannelPool}. The returned {@link Future} is notified once
32 * the acquire is successful and failed otherwise.
33 *
34 * <strong>Its important that an acquired is always released to the pool again, even if the {@link Channel}
35 * is explicitly closed..</strong>
36 */
37 Future<Channel> acquire();
38
39 /**
40 * Acquire a {@link Channel} from this {@link ChannelPool}. The given {@link Promise} is notified once
41 * the acquire is successful and failed otherwise.
42 *
43 * <strong>Its important that an acquired is always released to the pool again, even if the {@link Channel}
44 * is explicitly closed..</strong>
45 */
46 Future<Channel> acquire(Promise<Channel> promise);
47
48 /**
49 * Release a {@link Channel} back to this {@link ChannelPool}. The returned {@link Future} is notified once
50 * the release is successful and failed otherwise. When failed the {@link Channel} will automatically closed.
51 */
52 Future<Void> release(Channel channel);
53
54 /**
55 * Release a {@link Channel} back to this {@link ChannelPool}. The given {@link Promise} is notified once
56 * the release is successful and failed otherwise. When failed the {@link Channel} will automatically closed.
57 */
58 Future<Void> release(Channel channel, Promise<Void> promise);
59
60 @Override
61 void close();
62 }