netty5/transport-native-epoll/src/main/java/io/netty/channel/epoll/NativeStaticallyReferencedJniMethods.java
Norman Maurer 3add35fe82 Remove dependency on GLIBC 2.12 by using syscalls directly (#9797)
Motivation:

394a1b3485 introduced a hard dependency on GLIBC 2.12 which was not the case before. This had the effect of not be able to use the native epoll transports on platforms which ship with earlier versions of GLIBC.
To make things a backward compatible as possible we should not introduce such changes in a bugfix release.

Special thanks to @weissi with all the help to fix this.

Modifications:

- Use syscalls directly to remove dependency on GLIBC 2.12
- Make code consistent that needs newer GLIBC versions
- Adjust scattering read test to only run if recvmmsg syscall is supported
- Cleanup pom.xml as some stuff is not needed anymore after using syscalls.

Result:

Fixes https://github.com/netty/netty/issues/9758.
2019-11-23 21:17:39 +01:00

47 lines
1.8 KiB
Java

/*
* Copyright 2016 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.channel.epoll;
/**
* This class is necessary to break the following cyclic dependency:
* <ol>
* <li>JNI_OnLoad</li>
* <li>JNI Calls FindClass because RegisterNatives (used to register JNI methods) requires a class</li>
* <li>FindClass loads the class, but static members variables of that class attempt to call a JNI method which has not
* yet been registered.</li>
* <li>java.lang.UnsatisfiedLinkError is thrown because native method has not yet been registered.</li>
* </ol>
* Static members which call JNI methods must not be declared in this class!
*/
final class NativeStaticallyReferencedJniMethods {
private NativeStaticallyReferencedJniMethods() { }
static native int epollin();
static native int epollout();
static native int epollrdhup();
static native int epollet();
static native int epollerr();
static native long ssizeMax();
static native int tcpMd5SigMaxKeyLen();
static native int iovMax();
static native int uioMaxIov();
static native boolean isSupportingSendmmsg();
static native boolean isSupportingRecvmmsg();
static native boolean isSupportingTcpFastopen();
static native String kernelVersion();
}