Move generic unix classes/interfaces out of epoll package

Motivation:

As we plan to have other native transports soon (like a kqueue transport) we should move unix classes/interfaces out of the epoll package so we
introduce other implementations without breaking stuff before the next stable release.

Modifications:

Create a new io.netty.channel.unix package and move stuff over there.

Result:

Possible to introduce other native impls beside epoll.

transport-native-epoll/src/main/c/io_netty_channel_unix_FileDescriptor.c

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2015 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.
+ */
+#include <jni.h>
+#include <unistd.h>
+#include <errno.h>
+#include "io_netty_channel_unix_FileDescriptor.h"
+
+JNIEXPORT int JNICALL Java_io_netty_channel_unix_FileDescriptor_close(JNIEnv* env, jclass clazz, jint fd) {
+   if (close(fd) < 0) {
+       return -errno;
+   }
+   return 0;
+}

transport-native-epoll/src/main/c/io_netty_channel_unix_FileDescriptor.h

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2014 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.
+ */
+#include <jni.h>
+
+int Java_io_netty_channel_unix_FileDescriptor_close(JNIEnv* env, jclass clazz, jint fd);

transport-native-epoll/src/main/java/io/netty/channel/epoll/AbstractEpollChannel.java

@@ -23,15 +23,16 @@
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelMetadata;
 import io.netty.channel.EventLoop;
-import io.netty.channel.FileDescriptor;
+import io.netty.channel.unix.FileDescriptor;
+import io.netty.channel.unix.UnixChannel;
 import io.netty.util.ReferenceCountUtil;
 import io.netty.util.internal.OneTimeTask;
 
 import java.net.InetSocketAddress;
 import java.nio.ByteBuffer;
 import java.nio.channels.UnresolvedAddressException;
 
-abstract class AbstractEpollChannel extends AbstractChannel {
+abstract class AbstractEpollChannel extends AbstractChannel implements UnixChannel {
     private static final ChannelMetadata DATA = new ChannelMetadata(false);
     private final int readFlag;
     private volatile FileDescriptor fileDescriptor;
@@ -44,7 +45,7 @@ abstract class AbstractEpollChannel extends AbstractChannel {
     }
 
     AbstractEpollChannel(Channel parent, int fd, int flag, boolean active) {
-        this(parent, new NativeFileDescriptor(fd), flag, active);
+        this(parent, new FileDescriptor(fd), flag, active);
     }
 
     AbstractEpollChannel(Channel parent, FileDescriptor fd, int flag, boolean active) {
@@ -76,9 +77,7 @@ boolean isFlagSet(int flag) {
         return (flags & flag) != 0;
     }
 
-    /**
-     * Returns the {@link FileDescriptor} that is used by this {@link Channel}.
-     */
+    @Override
     public final FileDescriptor fd() {
         return fileDescriptor;
     }

transport-native-epoll/src/main/java/io/netty/channel/epoll/AbstractEpollServerChannel.java

@@ -20,8 +20,8 @@
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.EventLoop;
-import io.netty.channel.FileDescriptor;
 import io.netty.channel.ServerChannel;
+import io.netty.channel.unix.FileDescriptor;
 
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;

transport-native-epoll/src/main/java/io/netty/channel/epoll/AbstractEpollStreamChannel.java

@@ -28,10 +28,9 @@
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.ConnectTimeoutException;
 import io.netty.channel.DefaultFileRegion;
-import io.netty.channel.EventLoop;
-import io.netty.channel.FileDescriptor;
 import io.netty.channel.RecvByteBufAllocator;
 import io.netty.channel.socket.ChannelInputShutdownEvent;
+import io.netty.channel.unix.FileDescriptor;
 import io.netty.util.internal.PlatformDependent;
 import io.netty.util.internal.StringUtil;
 

transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollChannelOption.java

@@ -16,6 +16,7 @@
 package io.netty.channel.epoll;
 
 import io.netty.channel.ChannelOption;
+import io.netty.channel.unix.DomainSocketReadMode;
 
 public final class EpollChannelOption {
     private static final Class<EpollChannelOption> T = EpollChannelOption.class;

transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollDatagramChannel.java

@@ -25,11 +25,11 @@
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.DefaultAddressedEnvelope;
-import io.netty.channel.FileDescriptor;
 import io.netty.channel.RecvByteBufAllocator;
 import io.netty.channel.socket.DatagramChannel;
 import io.netty.channel.socket.DatagramChannelConfig;
 import io.netty.channel.socket.DatagramPacket;
+import io.netty.channel.unix.FileDescriptor;
 import io.netty.util.internal.PlatformDependent;
 import io.netty.util.internal.StringUtil;
 

transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollDomainSocketChannel.java

@@ -19,11 +19,13 @@
 import io.netty.channel.ChannelConfig;
 import io.netty.channel.ChannelOutboundBuffer;
 import io.netty.channel.ChannelPipeline;
-import io.netty.channel.FileDescriptor;
+import io.netty.channel.unix.DomainSocketAddress;
+import io.netty.channel.unix.DomainSocketChannel;
+import io.netty.channel.unix.FileDescriptor;
 
 import java.net.SocketAddress;
 
-public final class EpollDomainSocketChannel extends AbstractEpollStreamChannel {
+public final class EpollDomainSocketChannel extends AbstractEpollStreamChannel implements DomainSocketChannel {
     private final EpollDomainSocketChannelConfig config = new EpollDomainSocketChannelConfig(this);
 
     private volatile DomainSocketAddress local;
@@ -107,7 +109,7 @@ protected boolean doWriteSingle(ChannelOutboundBuffer in, int writeSpinCount) th
 
     @Override
     protected Object filterOutboundMessage(Object msg) {
-        if (msg instanceof NativeFileDescriptor) {
+        if (msg instanceof FileDescriptor) {
             return msg;
         }
         return super.filterOutboundMessage(msg);
@@ -150,7 +152,7 @@ private void epollInReadFd() {
                     readPending = false;
 
                     try {
-                        pipeline.fireChannelRead(new NativeFileDescriptor(socketFd));
+                        pipeline.fireChannelRead(new FileDescriptor(socketFd));
                     } catch (Throwable t) {
                         // keep on reading as we use epoll ET and need to consume everything from the socket
                         pipeline.fireChannelReadComplete();

transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollDomainSocketChannelConfig.java

@@ -21,10 +21,13 @@
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.MessageSizeEstimator;
 import io.netty.channel.RecvByteBufAllocator;
+import io.netty.channel.unix.DomainSocketChannelConfig;
+import io.netty.channel.unix.DomainSocketReadMode;
 
 import java.util.Map;
 
-public final class EpollDomainSocketChannelConfig extends EpollChannelConfig {
+public final class EpollDomainSocketChannelConfig extends EpollChannelConfig
+        implements DomainSocketChannelConfig {
     private volatile DomainSocketReadMode mode =
             DomainSocketReadMode.BYTES;
 
@@ -124,15 +127,7 @@ public EpollDomainSocketChannelConfig setEpollMode(EpollMode mode) {
         return this;
     }
 
-    /**
-     * Change the {@link DomainSocketReadMode} for the channel. The default is
-     * {@link DomainSocketReadMode#BYTES} which means bytes will be read from the
-     * {@link Channel} and passed through the pipeline. If
-     * {@link DomainSocketReadMode#FILE_DESCRIPTORS} is used
-     * {@link NativeFileDescriptor}s will be passed through the {@link ChannelPipeline}.
-     *
-     * This setting can be modified on the fly if needed.
-     */
+    @Override
     public EpollDomainSocketChannelConfig setReadMode(DomainSocketReadMode mode) {
         if (mode == null) {
             throw new NullPointerException("mode");
@@ -141,9 +136,7 @@ public EpollDomainSocketChannelConfig setReadMode(DomainSocketReadMode mode) {
         return this;
     }
 
-    /**
-     * Return the {@link DomainSocketReadMode} for the channel.
-     */
+    @Override
     public DomainSocketReadMode getReadMode() {
         return mode;
     }

transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollServerDomainSocketChannel.java

@@ -16,15 +16,18 @@
 package io.netty.channel.epoll;
 
 import io.netty.channel.Channel;
-import io.netty.channel.FileDescriptor;
+import io.netty.channel.unix.DomainSocketAddress;
+import io.netty.channel.unix.FileDescriptor;
+import io.netty.channel.unix.ServerDomainSocketChannel;
 import io.netty.util.internal.logging.InternalLogger;
 import io.netty.util.internal.logging.InternalLoggerFactory;
 
 import java.io.File;
 import java.net.SocketAddress;
 
 
-public final class EpollServerDomainSocketChannel extends AbstractEpollServerChannel {
+public final class EpollServerDomainSocketChannel extends AbstractEpollServerChannel
+        implements ServerDomainSocketChannel {
     private static final InternalLogger logger = InternalLoggerFactory.getInstance(
             EpollServerDomainSocketChannel.class);
 

transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollServerSocketChannel.java

@@ -17,8 +17,8 @@
 
 import io.netty.channel.Channel;
 import io.netty.channel.EventLoop;
-import io.netty.channel.FileDescriptor;
 import io.netty.channel.socket.ServerSocketChannel;
+import io.netty.channel.unix.FileDescriptor;
 
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;

transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollSocketChannel.java

@@ -19,9 +19,9 @@
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.EventLoop;
-import io.netty.channel.FileDescriptor;
 import io.netty.channel.socket.ServerSocketChannel;
 import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.unix.FileDescriptor;
 import io.netty.util.concurrent.GlobalEventExecutor;
 import io.netty.util.internal.OneTimeTask;
 

transport-native-epoll/src/main/java/io/netty/channel/epoll/Native.java

@@ -18,6 +18,7 @@
 
 import io.netty.channel.ChannelException;
 import io.netty.channel.DefaultFileRegion;
+import io.netty.channel.unix.DomainSocketAddress;
 import io.netty.util.internal.EmptyArrays;
 import io.netty.util.internal.NativeLibraryLoader;
 import io.netty.util.internal.PlatformDependent;

transport-native-epoll/src/main/java/io/netty/channel/epoll/DomainSocketAddress.java → transport-native-epoll/src/main/java/io/netty/channel/unix/DomainSocketAddress.java

@@ -13,11 +13,15 @@
  * License for the specific language governing permissions and limitations
  * under the License.
  */
-package io.netty.channel.epoll;
+package io.netty.channel.unix;
 
 import java.io.File;
 import java.net.SocketAddress;
 
+/**
+ * A address for a
+ * <a href="http://en.wikipedia.org/wiki/Unix_domain_socket">Unix Domain Socket</a>.
+ */
 public final class DomainSocketAddress extends SocketAddress {
     private final String socketPath;
 

transport-native-epoll/src/main/java/io/netty/channel/unix/DomainSocketChannel.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2015 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.unix;
+
+/**
+ * A {@link UnixChannel} that supports communication via
+ * <a href="http://en.wikipedia.org/wiki/Unix_domain_socket">Unix Domain Socket</a>.
+ */
+public interface DomainSocketChannel extends UnixChannel {
+    @Override
+    DomainSocketAddress remoteAddress();
+
+    @Override
+    DomainSocketAddress localAddress();
+
+    @Override
+    DomainSocketChannelConfig config();
+}

transport-native-epoll/src/main/java/io/netty/channel/unix/DomainSocketChannelConfig.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2015 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.unix;
+
+import io.netty.buffer.ByteBufAllocator;
+import io.netty.channel.ChannelConfig;
+import io.netty.channel.MessageSizeEstimator;
+import io.netty.channel.RecvByteBufAllocator;
+
+/**
+ * Special {@link ChannelConfig} for {@link DomainSocketChannel}s.
+ */
+public interface DomainSocketChannelConfig extends ChannelConfig {
+
+    @Override
+    DomainSocketChannelConfig setMaxMessagesPerRead(int maxMessagesPerRead);
+
+    @Override
+    DomainSocketChannelConfig setConnectTimeoutMillis(int connectTimeoutMillis);
+
+    @Override
+    DomainSocketChannelConfig setWriteSpinCount(int writeSpinCount);
+
+    @Override
+    DomainSocketChannelConfig setAllocator(ByteBufAllocator allocator);
+
+    @Override
+    DomainSocketChannelConfig setRecvByteBufAllocator(RecvByteBufAllocator allocator);
+
+    @Override
+    DomainSocketChannelConfig setAutoRead(boolean autoRead);
+
+    @Override
+    DomainSocketChannelConfig setAutoClose(boolean autoClose);
+
+    @Override
+    DomainSocketChannelConfig setWriteBufferHighWaterMark(int writeBufferHighWaterMark);
+
+    @Override
+    DomainSocketChannelConfig setWriteBufferLowWaterMark(int writeBufferLowWaterMark);
+
+    @Override
+    DomainSocketChannelConfig setMessageSizeEstimator(MessageSizeEstimator estimator);
+
+    /**
+     * Change the {@link DomainSocketReadMode} for the channel. The default is
+     * {@link DomainSocketReadMode#BYTES} which means bytes will be read from the
+     * {@link io.netty.channel.Channel} and passed through the pipeline. If
+     * {@link DomainSocketReadMode#FILE_DESCRIPTORS} is used
+     * {@link FileDescriptor}s will be passed through the {@link io.netty.channel.ChannelPipeline}.
+     *
+     * This setting can be modified on the fly if needed.
+     */
+    DomainSocketChannelConfig setReadMode(DomainSocketReadMode mode);
+
+    /**
+     * Return the {@link DomainSocketReadMode} for the channel.
+     */
+    DomainSocketReadMode getReadMode();
+}