Netty leak detector can cause native image build to randomly fail

[stuartwdouglas]

2019-01-19T23:00:20.9795528Z Error: Detected a direct/mapped ByteBuffer in the image heap. A direct ByteBuffer has a pointer to unmanaged C memory, and C memory from the image generator is not available at image run time. A mapped ByteBuffer references a file descriptor, which is no longer open and mapped at run time. The object was probably created by a class initializer and is reachable from a static field. By default, all class initialization is done during native image building.You can manually delay class initialization to image run time by using the option --delay-class-initialization-to-runtime=. Or you can write your own initialization methods and call them explicitly from your main entry point.
2019-01-19T23:00:20.9796370Z Trace: object io.netty.buffer.UnpooledByteBufAllocator$InstrumentedUnpooledDirectByteBuf
2019-01-19T23:00:20.9796602Z object io.netty.util.ResourceLeakDetector$DefaultResourceLeak
2019-01-19T23:00:20.9796780Z object java.util.concurrent.ConcurrentHashMap$Node
2019-01-19T23:00:20.9796982Z object java.util.concurrent.ConcurrentHashMap$Node[]
2019-01-19T23:00:20.9797177Z object java.util.concurrent.ConcurrentHashMap
2019-01-19T23:00:20.9797353Z object io.netty.util.ResourceLeakDetector
2019-01-19T23:00:20.9797554Z method io.netty.buffer.AbstractByteBufAllocator.toLeakAwareBuffer(ByteBuf)
2019-01-19T23:00:21.5832486Z Call path from entry point to io.netty.buffer.AbstractByteBufAllocator.toLeakAwareBuffer(ByteBuf):
2019-01-19T23:00:21.5858141Z at io.netty.buffer.AbstractByteBufAllocator.toLeakAwareBuffer(AbstractByteBufAllocator.java:39)
2019-01-19T23:00:21.5859220Z at io.netty.buffer.PooledByteBufAllocator.newHeapBuffer(PooledByteBufAllocator.java:314)
2019-01-19T23:00:21.5860891Z at io.netty.buffer.AbstractByteBufAllocator.heapBuffer(AbstractByteBufAllocator.java:166)
2019-01-19T23:00:21.5861166Z at io.netty.buffer.AbstractByteBufAllocator.buffer(AbstractByteBufAllocator.java:123)
2019-01-19T23:00:21.5861435Z at io.netty.buffer.AbstractByteBuf.readBytes(AbstractByteBuf.java:867)
2019-01-19T23:00:21.5861736Z at io.netty.handler.codec.ByteToMessageDecoder.handlerRemoved(ByteToMessageDecoder.java:247)
2019-01-19T23:00:21.5862252Z at io.netty.channel.DefaultChannelPipeline.callHandlerAdded0(DefaultChannelPipeline.java:643)
2019-01-19T23:00:21.5862428Z at io.netty.channel.DefaultChannelPipeline.access$000(DefaultChannelPipeline.java:46)
2019-01-19T23:00:21.5862514Z at io.netty.channel.DefaultChannelPipeline$4.run(DefaultChannelPipeline.java:281)
2019-01-19T23:00:21.5862636Z at com.oracle.svm.core.jdk.RuntimeSupport.executeHooks(RuntimeSupport.java:144)
2019-01-19T23:00:21.5862723Z at com.oracle.svm.core.jdk.RuntimeSupport.executeStartupHooks(RuntimeSupport.java:89)
2019-01-19T23:00:21.5862831Z at com.oracle.svm.core.JavaMainWrapper.run(JavaMainWrapper.java:156)
2019-01-19T23:00:21.5862923Z at com.oracle.svm.core.code.IsolateEnterStub.JavaMainWrapper_run_5087f5482cc9a6abc971913ece43acb471d2631b(generated:0)
2019-01-19T23:00:21.5864406Z Error: Detected a direct/mapped ByteBuffer in the image heap. A direct ByteBuffer has a pointer to unmanaged C memory, and C memory from the image generator is not available at image run time. A mapped ByteBuffer references a file descriptor, which is no longer open and mapped at run time. The object was probably created by a class initializer and is reachable from a static field. By default, all class initialization is done during native image building.You can manually delay class initialization to image run time by using the option --delay-class-initialization-to-runtime=. Or you can write your own initialization methods and call them explicitly from your main entry point.
2019-01-19T23:00:21.5864695Z Trace: object io.netty.buffer.UnpooledByteBufAllocator$InstrumentedUnpooledDirectByteBuf
2019-01-19T23:00:21.5864804Z object io.netty.util.ResourceLeakDetector$DefaultResourceLeak
2019-01-19T23:00:21.5864882Z object java.util.concurrent.ConcurrentHashMap$Node
2019-01-19T23:00:21.5864971Z object java.util.concurrent.ConcurrentHashMap$Node[]
2019-01-19T23:00:21.5865044Z object java.util.concurrent.ConcurrentHashMap
2019-01-19T23:00:21.5865125Z object io.netty.util.ResourceLeakDetector
2019-01-19T23:00:21.5865197Z method io.netty.buffer.AbstractByteBufAllocator.toLeakAwareBuffer(ByteBuf)
2019-01-19T23:00:21.5865301Z Call path from entry point to io.netty.buffer.AbstractByteBufAllocator.toLeakAwareBuffer(ByteBuf):
2019-01-19T23:00:21.5865395Z at io.netty.buffer.AbstractByteBufAllocator.toLeakAwareBuffer(AbstractByteBufAllocator.java:39)
2019-01-19T23:00:21.5865783Z at io.netty.buffer.PooledByteBufAllocator.newHeapBuffer(PooledByteBufAllocator.java:314)
2019-01-19T23:00:21.5865871Z at io.netty.buffer.AbstractByteBufAllocator.heapBuffer(AbstractByteBufAllocator.java:166)
2019-01-19T23:00:21.5866074Z at io.netty.buffer.AbstractByteBufAllocator.buffer(AbstractByteBufAllocator.java:123)
2019-01-19T23:00:21.5866155Z at io.netty.buffer.AbstractByteBuf.readBytes(AbstractByteBuf.java:867)
2019-01-19T23:00:21.5866254Z at io.netty.handler.codec.ByteToMessageDecoder.handlerRemoved(ByteToMessageDecoder.java:247)
2019-01-19T23:00:21.5866341Z at io.netty.channel.DefaultChannelPipeline.callHandlerAdded0(DefaultChannelPipeline.java:643)
2019-01-19T23:00:21.5866466Z at io.netty.channel.DefaultChannelPipeline.access$000(DefaultChannelPipeline.java:46)
2019-01-19T23:00:21.5866549Z at io.netty.channel.DefaultChannelPipeline$4.run(DefaultChannelPipeline.java:281)
2019-01-19T23:00:21.5866648Z at com.oracle.svm.core.jdk.RuntimeSupport.executeHooks(RuntimeSupport.java:144)
2019-01-19T23:00:21.5866743Z at com.oracle.svm.core.jdk.RuntimeSupport.executeStartupHooks(RuntimeSupport.java:89)
2019-01-19T23:00:21.5869974Z at com.oracle.svm.core.JavaMainWrapper.run(JavaMainWrapper.java:156)
2019-01-19T23:00:21.5873639Z at com.oracle.svm.core.code.IsolateEnterStub.JavaMainWrapper_run_5087f5482cc9a6abc971913ece43acb471d2631b(generated:0)
2019-01-19T23:00:21.5874422Z