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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    *   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.netty.channel.kqueue;
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 KQueueStaticallyReferencedJniMethods {
30      private KQueueStaticallyReferencedJniMethods() { }
31  
32      static native short evAdd();
33      static native short evEnable();
34      static native short evDisable();
35      static native short evDelete();
36      static native short evClear();
37      static native short evEOF();
38      static native short evError();
39  
40      // data/hint fflags for EVFILT_SOCK, shared with userspace.
41      static native short noteReadClosed();
42      static native short noteConnReset();
43      static native short noteDisconnected();
44  
45      static native short evfiltRead();
46      static native short evfiltWrite();
47      static native short evfiltUser();
48      static native short evfiltSock();
49  
50      // Flags for connectx(2)
51      static native int connectResumeOnReadWrite();
52      static native int connectDataIdempotent();
53  
54      // Sysctl values.
55      static native int fastOpenClient();
56      static native int fastOpenServer();
57  }