Allow to recover from exception triggered by accept() more easily

This is done by stop accept() new sockets for 1 seconds
Beside this this commit also makes sure accept() exceptions of OioServerSocketChannel trigger
the fireExceptionCaught(...). The same is true fo the AioServerSocketChannel.

transport/src/main/java/io/netty/bootstrap/ServerBootstrap.java

@@ -18,6 +18,7 @@ package io.netty.bootstrap;
 import io.netty.buffer.MessageBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
+import io.netty.channel.ChannelConfig;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundMessageHandler;
@@ -35,6 +36,7 @@ import io.netty.util.internal.logging.InternalLoggerFactory;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.concurrent.TimeUnit;
 
 /**
  * {@link Bootstrap} sub-class which allows easy bootstrap of {@link ServerChannel}
@@ -267,6 +269,25 @@ public final class ServerBootstrap extends AbstractBootstrap<ServerBootstrap, Se
                 }
             }
         }
+
+        @Override
+        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+            final ChannelConfig config = ctx.channel().config();
+            if (config.isAutoRead()) {
+                // stop accept new connections for 1 second to allow the channel to recover
+                // See https://github.com/netty/netty/issues/1328
+                config.setAutoRead(false);
+                ctx.channel().eventLoop().schedule(new Runnable() {
+                    @Override
+                    public void run() {
+                       config.setAutoRead(true);
+                    }
+                }, 1, TimeUnit.SECONDS);
+            }
+            // still let the exceptionCaught event flow through the pipeline to give the user
+            // a chance to do something with it
+            ctx.fireExceptionCaught(cause);
+        }
     }
 
     @Override

transport/src/main/java/io/netty/channel/socket/aio/AioServerSocketChannel.java

@@ -216,6 +216,7 @@ public class AioServerSocketChannel extends AbstractAioChannel implements Server
             // log something
             if (channel.isOpen() && ! asyncClosed) {
                 logger.warn("Failed to create a new channel from an accepted socket.", t);
+                channel.pipeline().fireExceptionCaught(t);
             }
         }
     }

transport/src/main/java/io/netty/channel/socket/oio/OioServerSocketChannel.java

@@ -160,26 +160,26 @@ public class OioServerSocketChannel extends AbstractOioMessageChannel
             return -1;
         }
 
-        Socket s = null;
         try {
-            s = socket.accept();
-            if (s != null) {
-                buf.add(new OioSocketChannel(this, null, s));
-                return 1;
+            Socket s = socket.accept();
+            try {
+                if (s != null) {
+                    buf.add(new OioSocketChannel(this, null, s));
+                    return 1;
+                }
+            } catch (Throwable t) {
+                logger.warn("Failed to create a new channel from an accepted socket.", t);
+                if (s != null) {
+                    try {
+                        s.close();
+                    } catch (Throwable t2) {
+                        logger.warn("Failed to close a socket.", t2);
+                    }
+                }
             }
         } catch (SocketTimeoutException e) {
             // Expected
-        } catch (Throwable t) {
-            logger.warn("Failed to create a new channel from an accepted socket.", t);
-            if (s != null) {
-                try {
-                    s.close();
-                } catch (Throwable t2) {
-                    logger.warn("Failed to close a socket.", t2);
-                }
-            }
         }
-
         return 0;
     }