SpigotMC#3828: Set allocator using Netty system property to apply pooled allocator default globally

Author: onebeastchris

proxy/src/main/java/net/md_5/bungee/BungeeCord.java

@@ -262,6 +262,14 @@ public void start() throws Exception
             ResourceLeakDetector.setLevel( ResourceLeakDetector.Level.DISABLED ); // Eats performance
         }
 
+        // https://github.com/netty/netty/wiki/Netty-4.2-Migration-Guide
+        // The adaptive allocator, the new default allocator since Netty 4.2, has some memory issues.
+        // Setting it globally also ensures that any plugins would also use the pooled allocator.
+        if ( System.getProperty( "io.netty.allocator.type" ) == null )
+        {
+            System.setProperty( "io.netty.allocator.type", "pooled" );
+        }
+
         eventLoops = PipelineUtils.newEventLoopGroup( 0, new ThreadFactoryBuilder().setNameFormat( "Netty IO Thread #%1$d" ).build() );
 
         File moduleDirectory = new File( "modules" );

proxy/src/main/java/net/md_5/bungee/netty/PipelineUtils.java

@@ -1,7 +1,6 @@
 package net.md_5.bungee.netty;
 
 import com.google.common.base.Preconditions;
-import io.netty.buffer.PooledByteBufAllocator;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelException;
 import io.netty.channel.ChannelOption;
@@ -219,9 +218,6 @@ public boolean accept(Channel ch)
             {
                 // IP_TOS is not supported (Windows XP / Windows Server 2003)
             }
-            // https://github.com/netty/netty/wiki/Netty-4.2-Migration-Guide
-            // TODO: check for AdaptiveByteBufAllocator
-            ch.config().setAllocator( PooledByteBufAllocator.DEFAULT );
             ch.config().setWriteBufferWaterMark( MARK );
 
             ch.pipeline().addLast( FRAME_DECODER, new Varint21FrameDecoder() );