Intermittent test exception: failed to register an accepted channel

[tsegismont]

Version

5.1

Context

This exception happens intermittently in the Vert.x core test suite:

[vert.x-acceptor-thread-0] WARN io.netty.bootstrap.ServerBootstrap - Failed to register an accepted channel: [id: 0x26ff2859, L:0.0.0.0/0.0.0.0:1234]
java.lang.IllegalStateException
    at io.vertx.core@5.1.0-SNAPSHOT/io.vertx.core.net.impl.VertxEventLoopGroup.next(VertxEventLoopGroup.java:37)
    at io.vertx.core@5.1.0-SNAPSHOT/io.vertx.core.net.impl.VertxEventLoopGroup.register(VertxEventLoopGroup.java:53)
    at io.netty.transport@4.2.12.Final/io.netty.bootstrap.ServerBootstrap$ServerBootstrapAcceptor.channelRead(ServerBootstrap.java:247)
    at io.netty.transport@4.2.12.Final/io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
    at io.netty.transport@4.2.12.Final/io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1429)

It doesn't block the build of fail any test, and it doesn't seem to be specific to a transport, although it happens more often with io_uring.

This is probably related to io.vertx.core.net.impl.tcp.NetServerImpl#handleShutdown :

vert.x/vertx-core/src/main/java/io/vertx/core/net/impl/tcp/NetServerImpl.java

Line 612 in b0d625f

// THIS CAN BE RACY