NPE in websockets-next

[RobertoUa]

Describe the bug

Getting NPE

java.lang.NullPointerException: Cannot invoke "java.lang.Short.shortValue()" because the return value of "io.vertx.core.http.WebSocketBase.closeStatusCode()" is null
	at io.quarkus.websockets.next.runtime.WebSocketConnectionBase.closeReason(WebSocketConnectionBase.java:134)
	at myapp.core.stream.Streaming_WebSocketServerEndpoint.doOnClose(Unknown Source)
	at io.quarkus.websockets.next.runtime.WebSocketEndpointBase$4.call(WebSocketEndpointBase.java:158)
	at io.quarkus.websockets.next.runtime.WebSocketEndpointBase$4.call(WebSocketEndpointBase.java:152)
	at io.vertx.core.impl.ContextImpl.lambda$executeBlocking$0(ContextImpl.java:178)
	at io.vertx.core.impl.ContextInternal.dispatch(ContextInternal.java:279)
	at io.vertx.core.impl.ContextImpl.lambda$internalExecuteBlocking$2(ContextImpl.java:210)
	at io.quarkus.vertx.core.runtime.VertxCoreRecorder$14.runWith(VertxCoreRecorder.java:635)
	at org.jboss.threads.EnhancedQueueExecutor$Task.doRunWith(EnhancedQueueExecutor.java:2516)
	at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2495)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1521)
	at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:11)
	at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:11)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:1583)

It seems like error is happening here

quarkus/extensions/websockets-next/runtime/src/main/java/io/quarkus/websockets/next/runtime/WebSocketConnectionBase.java

Line 134 in 450681e

return new CloseReason(ws.closeStatusCode(), ws.closeReason());

closeStatusCode is Short and it's null. It throws when it tries to unbox (Short -> short)

Expected behavior

No response

Actual behavior

No response

How to Reproduce?

No response

Output of uname -a or ver

No response

Output of java -version

No response

Quarkus version or git rev

No response

Build tool (ie. output of mvnw --version or gradlew --version)

No response

Additional information

No response

[geoand]

cc @mkouba

[mkouba]

Hm, this could only happen if an @OnClose callback accepts a CloseReason param but when it's called the underlying WebSocket is not closed yet. And that should not normally happen.

@RobertoUa Could you tell me a little bit more about your application/use case?

[RobertoUa]

it happens every time the connection is terminated abruptly. Reproduces every time when I connect with websocat and then kill -9 it.
But sometimes it happens with a regular browser, I couldn't figure out how and when it happens.

I also don't think it's a timeout from reverse proxy/load balancer, I do pings and connections could stay alive for hours.

[mkouba]

Reproduces every time when I connect with websocat and then kill -9 it.

Yes, I was able to reproduce the problem locally. There's not much we can do about it though. I've modified the code to use CloseReason.INTERNAL_SERVER_ERROR instead.