1 /*
2 * Copyright 2016 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.epoll;
17
18 /**
19 * This class is necessary to break the following cyclic dependency:
20 * <ol>
21 * <li>JNI_OnLoad</li>
22 * <li>JNI Calls FindClass because RegisterNatives (used to register JNI methods) requires a class</li>
23 * <li>FindClass loads the class, but static members variables of that class attempt to call a JNI method which has not
24 * yet been registered.</li>
25 * <li>java.lang.UnsatisfiedLinkError is thrown because native method has not yet been registered.</li>
26 * </ol>
27 * Static members which call JNI methods must not be declared in this class!
28 */
29 final class NativeStaticallyReferencedJniMethods {
30
31 private NativeStaticallyReferencedJniMethods() { }
32
33 static native int epollin();
34 static native int epollout();
35 static native int epollrdhup();
36 static native int epollet();
37 static native int epollerr();
38 static native long ssizeMax();
39 static native int tcpMd5SigMaxKeyLen();
40 static native int iovMax();
41 static native int uioMaxIov();
42 static native boolean isSupportingSendmmsg();
43 static native boolean isSupportingTcpFastopen();
44 static native String kernelVersion();
45 }