1 /*
2 * Copyright 2009 Red Hat, Inc.
3 *
4 * Red Hat licenses this file to you under the Apache License, version 2.0
5 * (the "License"); you may not use this file except in compliance with the
6 * 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 org.jboss.netty.channel.socket.nio;
17
18 import java.nio.ByteBuffer;
19 import java.nio.channels.WritableByteChannel;
20
21 import org.jboss.netty.channel.Channel;
22 import org.jboss.netty.channel.ChannelConfig;
23 import org.jboss.netty.channel.socket.DatagramChannel;
24 import org.jboss.netty.channel.socket.DatagramChannelConfig;
25
26 /**
27 * A {@link DatagramChannelConfig} for a NIO TCP/IP {@link DatagramChannel}.
28 *
29 * <h3>Available options</h3>
30 *
31 * In addition to the options provided by {@link ChannelConfig} and
32 * {@link DatagramChannelConfig}, {@link NioDatagramChannelConfig} allows the
33 * following options in the option map:
34 *
35 * <table border="1" cellspacing="0" cellpadding="6">
36 * <tr>
37 * <th>Name</th><th>Associated setter method</th>
38 * </tr><tr>
39 * <td>{@code "writeBufferHighWaterMark"}</td><td>{@link #setWriteBufferHighWaterMark(int)}</td>
40 * </tr><tr>
41 * <td>{@code "writeBufferLowWaterMark"}</td><td>{@link #setWriteBufferLowWaterMark(int)}</td>
42 * </tr><tr>
43 * <td>{@code "writeSpinCount"}</td><td>{@link #setWriteSpinCount(int)}</td>
44 * </tr><tr>
45 * </table>
46 *
47 * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
48 * @author <a href="http://gleamynode.net/">Trustin Lee</a>
49 * @author Daniel Bevenius (dbevenius@jboss.com)
50 *
51 * @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
52 */
53 public interface NioDatagramChannelConfig extends DatagramChannelConfig {
54
55 /**
56 * Returns the high water mark of the write buffer. If the number of bytes
57 * queued in the write buffer exceeds this value, {@link Channel#isWritable()}
58 * will start to return {@code true}.
59 */
60 int getWriteBufferHighWaterMark();
61
62 /**
63 * Sets the high water mark of the write buffer. If the number of bytes
64 * queued in the write buffer exceeds this value, {@link Channel#isWritable()}
65 * will start to return {@code true}.
66 */
67 void setWriteBufferHighWaterMark(int writeBufferHighWaterMark);
68
69 /**
70 * Returns the low water mark of the write buffer. Once the number of bytes
71 * queued in the write buffer exceeded the
72 * {@linkplain #setWriteBufferHighWaterMark(int) high water mark} and then
73 * dropped down below this value, {@link Channel#isWritable()} will return
74 * {@code false} again.
75 */
76 int getWriteBufferLowWaterMark();
77
78 /**
79 * Sets the low water mark of the write buffer. Once the number of bytes
80 * queued in the write buffer exceeded the
81 * {@linkplain #setWriteBufferHighWaterMark(int) high water mark} and then
82 * dropped down below this value, {@link Channel#isWritable()} will return
83 * {@code false} again.
84 */
85 void setWriteBufferLowWaterMark(int writeBufferLowWaterMark);
86
87 /**
88 * Returns the maximum loop count for a write operation until
89 * {@link WritableByteChannel#write(ByteBuffer)} returns a non-zero value.
90 * It is similar to what a spin lock is used for in concurrency programming.
91 * It improves memory utilization and write throughput depending on
92 * the platform that JVM runs on. The default value is {@code 16}.
93 */
94 int getWriteSpinCount();
95
96 /**
97 * Sets the maximum loop count for a write operation until
98 * {@link WritableByteChannel#write(ByteBuffer)} returns a non-zero value.
99 * It is similar to what a spin lock is used for in concurrency programming.
100 * It improves memory utilization and write throughput depending on
101 * the platform that JVM runs on. The default value is {@code 16}.
102 *
103 * @throws IllegalArgumentException
104 * if the specified value is {@code 0} or less than {@code 0}
105 */
106 void setWriteSpinCount(int writeSpinCount);
107 }